WO2021206616A1

WO2021206616A1 - Multi-connectivity operation in a wireless communication network

Info

Publication number: WO2021206616A1
Application number: PCT/SE2021/050308
Authority: WO
Inventors: Icaro L. J. Da Silva; Julien Muller
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2020-04-09
Filing date: 2021-04-07
Publication date: 2021-10-14

Abstract

A first network node (14) is configured to operate as a master network node for multi-connectivity operation of a wireless device (12). The first network node (14) receives a message that indicates that the wireless device (12) has executed a conditional handover. Based on receiving the message, the first network node (14) transmits a secondary node release request message (24) to a second network node (16) operating as a secondary network node for multi-connectivity operation of the wireless device (12). The secondary node release request message (24) requests release of resources for the wireless device (12) at the second network node (16). The first network node (14) may for example refrain from transmitting the secondary node release request message (24) in response to receiving a handover request acknowledge message, and instead wait to transmit the secondary node release request message (24) until reception of the message that indicates the wireless device (12) has executed the conditional handover.

Description

MULTI-CONNECTIVITY OPERATION IN A WIRELESS COMMUNICATION NETWORK

TECHNICAL FIELD

The present application relates generally to a wireless communication network, and relates more particularly to multi-connectivity operation in such a network.

BACKGROUND

Some reconfiguration procedures are particularly susceptible to failure in New Radio (NR) systems whose radio links are more prone to fast fading due to their higher operating frequencies. Conditional reconfiguration is one approach to improve robustness against failure in this regard. Under this approach, the network transmits a conditional reconfiguration to a wireless device and specifies a condition that is to trigger the wireless device to execute that conditional reconfiguration. The wireless device waits to execute the conditional reconfiguration until the wireless device detects that the condition is fulfilled. Once the device detects that condition, the device may autonomously execute the conditional reconfiguration without receiving any other signaling, so that the reconfiguration proves robust to link deterioration.

Although this conditional reconfiguration approach can improve robustness against failure, its use proves challenging in some contexts. For example, multi-connectivity refers to the simultaneous connection of a wireless device (e.g., at a radio resource control, RRC, layer) to multiple different radio network nodes, or to multiple different cells provided by different radio network nodes. Known approaches to conditional reconfiguration fail to adequately account for the multiplicity of radio network nodes or cells involved in multi-connectivity.

SUMMARY

Some embodiments herein facilitate conditional reconfiguration (e.g., conditional handover) in the context of multi-connectivity operation, where a wireless device is served by a master network node and a secondary network node. One or more embodiments in this regard preserve the wireless device’s service from the secondary network node, until the wireless device has actually executed conditional handover to a candidate target node. Some embodiments for example avoid prematurely releasing resources for the wireless device at the secondary network node, so that those resources remain intact during the interim between when the wireless device begins monitoring for fulfillment of a condition for executing the conditional handover and when the wireless device actually executes the conditional handover upon such fulfillment. These and other embodiments may be realized by the master network node delaying a request to the secondary network node to release resources for the wireless device, e.g., until the master network node receives a message indicating the conditional handover has been executed. Some embodiments may thereby allow a wireless device to achieve increased data rates with multi-connectivity operation, while also enjoying improved robustness of reconfiguration (e.g., handover) against failure. More particularly, embodiments herein include a method performed by a first network node configured to operate as a master network node for multi-connectivity operation of a wireless device. The method includes receiving a message that indicates a wireless device operating in multi-connectivity has executed a conditional handover. The method may further include, based on receiving the message, transmitting a secondary node release request message to a second network node operating as a secondary network node for multi connectivity operation of the wireless device, wherein the secondary node release request message requests release of resources for the wireless device at the second network node.

In some embodiments, the method also includes receiving, from the second network node, a secondary node release request acknowledge message confirming the secondary node release request message and/or confirming that the second network node has released resources for the wireless device at the second network node. Alternatively or additionally, the method may include, after or in conjunction with transmitting the secondary node release request message, receiving data from the second network node and forwarding the data to the candidate target node.

In some embodiments, the message is a handover success message that indicates the wireless device has successfully accessed a candidate target node for the conditional handover (or, more particularly, a cell of a candidate target node for the conditional handover).

The message in some embodiments may be received from the wireless device or from a candidate target node for the conditional handover.

In some embodiments, the method further comprises transmitting, from the first network node to a candidate target node, a handover request message that requests preparation of resources at the candidate target node for the conditional handover. In this case, the method may also comprise, after transmitting the handover request message, receiving from the candidate target node a handover request acknowledge message that informs the first network node about prepared resources at the candidate target node for the conditional handover. The method may further comprise refraining from transmitting the secondary node release request message to the second network node in response to receiving the handover request acknowledge message, and instead waiting to transmit the secondary node release request message to the second network node until the first network node receives the message that indicates the wireless device has executed the conditional handover.

In any of these embodiments, the secondary node release request message may indicate a cause of the secondary node release request message as being conditional MCG mobility or conditional master node mobility.

In any of these embodiments, the master network node may be a source master network node for the conditional handover and the second network node may be a source secondary network node for the conditional handover.

In any of these embodiments, the method may further comprise, based on receiving the message, initiating a handover cancel procedure towards one or more other candidate target nodes of the conditional handover.

In some embodiments, the method further comprises, after receiving the message that indicates the wireless device has executed the conditional handover, initiating an address indication procedure with the second network node in order to provide a data forwarding address to the second network node. Here, the data forwarding address is an address to which the second network node is to forward data for the wireless device.

In one embodiment, for example, the method further comprises transmitting, from the first network node to a candidate target node, a handover request message that requests preparation of resources at the candidate target node for the conditional handover. In this case, the method may also comprise, after transmitting the handover request, receiving from the candidate target node a handover request acknowledge message that informs the first network node about prepared resources at the candidate target node for the conditional handover. The method may further comprise refraining from initiating the address indication procedure with the second network node in response to receiving the handover request acknowledge message, and instead waiting to initiate the address indication procedure with the second network node until the first network node receives the message that indicates the wireless device has executed the conditional handover.

Embodiments herein also include corresponding apparatuses, computer programs, and carriers of those computer programs. Embodiments herein for instance include a network node (e.g., a first network node) configured to perform any of the steps of any of the embodiments described above. In particular, embodiments herein include a first network node configured to operate as a master network node for multi-connectivity operation of a wireless device. The first network node (e.g., via communication circuitry and processing circuitry) is configured to receive a message that indicates a wireless device operating in multi-connectivity has executed a conditional handover. The first network node is further configured to, based on receiving the message, transmit a secondary node release request message to a second network node operating as a secondary network node for multi-connectivity operation of the wireless device, wherein the secondary node release request message requests release of resources for the wireless device at the second network node.

Of course, the present invention is not limited to the above features and advantages. Indeed, those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a block diagram of a wireless communication network according to some embodiments.

Figure 2 is a logic flow diagram of a method performed by a first network node according to some embodiments. Figure 3 is a logic flow diagram of a method performed by a first network node according to other embodiments.

Figure 4 is a block diagram of a network node according to some embodiments.

Figure 5 is a signaling flow diagram of a master node to ng-eNB/gNB change procedure for unconditional handover according to some embodiments.

Figure 6 is a signaling flow diagram of a secondary node release procedure according to some embodiments.

Figure 7 is a signaling flow diagram of a master node to eNB change procedure for unconditional handover according to some embodiments.

Figure 8 is a logic flow diagram of a method performed by a first network node for conditional handover (CHO) preparation according to some embodiments.

Figure 9 is a signaling flow diagram for conditional handover (CHO) preparation according to some embodiments.

Figure 10 is a logic flow diagram of a method performed by a first network node for conditional handover (CHO) execution according to some embodiments.

Figure 11 is a signaling flow diagram for conditional handover (CHO) execution according to some embodiments.

Figure 12 is a signaling flow diagram of a handover success procedure according to some embodiments.

Figure 13 is a logic flow diagram of a method performed by a second network node according to some embodiments.

Figure 14 is a block diagram of a wireless communication network according to some embodiments.

Figure 15 is a block diagram of a user equipment according to some embodiments.

Figure 16 is a block diagram of a virtualization environment according to some embodiments.

Figure 17 is a block diagram of a communication network with a host computer according to some embodiments.

Figure 18 is a block diagram of a host computer according to some embodiments.

Figure 19 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

Figure 20 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

Figure 21 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

Figure 22 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. DETAILED DESCRIPTION

Figure 1 shows a wireless device 12 configured for use in a wireless communication network according to some embodiments. The wireless device 12 is configured for multi connectivity operation. Multi-connectivity in this regard refers to the simultaneous connection of the wireless device 12 (e.g., at a radio resource control, RRC, layer) to multiple different radio network nodes, or to multiple different cells provided by different radio network nodes. The multiple different radio network nodes or cells may use the same radio access technology (e.g., both may use Evolved Universal Terrestrial Radio Access (E-UTRA) or both may use New Radio (NR)). Or, the multiple different radio network nodes or cells may use different radio access technologies, e.g., one may use E-UTRA and another may use NR.

One example of multi-connectivity is dual connectivity (DC) in which the wireless device 12 is simultaneously connected to two different radio network nodes, or to two different cells provided by two different radio network nodes. In this case, the wireless device 12 may be configured with a so-called master cell group (MCG) and a secondary cell group (SCG), where the MCG includes one or more cells provided by the radio network node acting as a master node (MN) and the SCG includes one or more cells served by the radio network node acting as a secondary node (SN). The master node may be a master in the sense that it controls the secondary node and/or provides the control plane connection to the core network. For example, E-UTRA-NR (EN) DC refers to where the master node uses E-UTRA and the secondary node uses NR, whereas NR-E-UTRA (NE) refers to where the master node uses NR and the secondary node uses E-UTRA.

For example, in multi-connectivity operation, the wireless device 12 with multiple receivers (Rx) and/or transmitters (Tx) may utilize radio resources amongst one or more radio access technologies (e.g., New Radio, NR, and/or E-UTRA) provided by multiple distinct schedulers connected via a non-ideal backhaul. Multi-radio dual connectivity (MR-DC) in this regard is a generalization of Intra-E-UTRA DC, where a multiple Rx/Tx wireless device may be configured to utilize resources provided by two different nodes connected via a non-ideal backhaul, one providing NR access and the other one providing either E-UTRA or NR access. One node acts as the master node (MN) and the other as a secondary node (SN). E-UTRAN for instance supports MR-DC via E-UTRA-NR dual connectivity (EN-DC), in which a wireless device is connected to one eNB that acts as a MN and one en-gNB that acts as a secondary node (SN), where an en-gNB is the logical entity name of a gNB used as a Secondary Node in EN-DC. Either way, in MR-DC, the wireless device 12 may have a single Radio Resource Control (RRC) state, based on the MN RRC and a single control plane connection towards the core network.

In this context, Figure 1 shows a first network node 14 that operates as a master network node (i.e. , MN) for multi-connectivity operation of the wireless device 12. Figure 1 also shows a second network node 16 that operates as a secondary network node (i.e., SN) for multi-connectivity operation of the wireless device 12. During multi-connectivity operation, though, the first network node 14 decides to configure the wireless device 12 for handover with respect to one or more candidate target nodes 18-1,... 18-N. As a result of the handover, the master network node for the device’s multi-connectivity operation would change from being the first network node 14 to being one of the candidate target nodes 18-1...18-N.

Towards this end, the first network node 14 as shown transmits a handover request message 20 to each of one or more of the candidate target nodes 18-1... 18-N. The handover request message 20 requests preparation of resources at the candidate target node for the handover of the wireless device 12. Each candidate target node may return a response to the handover request message 20, to inform the first network node 14 whether resources were prepared for the handover at that candidate target node. As shown in this example, each candidate target node 18-1...18-N responds with a respective handover request acknowledgement (ACK) message 22 that informs the first network node 14 about prepared resources at the respective candidate target node for the handover. With resources prepared for the handover, the master network node 14 may transmit a handover command 13 to the wireless device 12, e.g., in the form of an RRC reconfiguration.

Notably, though, the first network node 14 according to some embodiments herein advantageously preserves the wireless device’s service from the second network node 16 in multi-connectivity operation, until the wireless device has actually executed handover to a candidate target node. The first network node 14 in this regard accounts for whether the handover is conditional or not. If, for example, the wireless device 12 is to execute the handover unconditionally in response to the handover command 13, the first network node 14 may go ahead and request release of resources for the wireless device 12 at the second network node 16, by transmitting a secondary node release request message 24 (or simply ‘release request message 24’) to the second network node 16 in response to receiving the handover request acknowledge message(s) 22. But, if the handover is a conditional handover such that the wireless device 12 is to execute the handover only upon the wireless device 12 detecting fulfillment of a condition, the first network node 14 may delay transmitting the secondary node release request message 24 to the second network node 16, e.g., until the master network node receives a message 26 indicating the conditional handover has been executed. The message 26 may for instance be a handover success message that indicates the wireless device 12 has successfully accessed a candidate target node for the handover. As shown in the handover timelines of Figure 1, therefore, the amount of time between when the first network node 14 receives the handover request acknowledge message(s) 22 and when the first network node 14 transmits the secondary node release request message 24 may be relatively longer if the handover is a conditional handover or relatively shorter if the handover is an unconditional handover. In this sense, then, transmission of the secondary node release request message 14 in the conditional handover case is delayed with respect to when the message 14 would have been transmitted had the handover been unconditional. Regardless, delaying the secondary node release request message 24 may advantageously avoid prematurely releasing resources for the wireless device 12 at the second network node 16, so that those resources remain intact during the interim between when the wireless device 12 begins monitoring for fulfillment of the condition for executing the conditional handover and when the wireless device 12 actually executes the conditional handover upon such fulfillment. Some embodiments may thereby allow the wireless device 12 to achieve increased data rates with multi-connectivity operation, while also enjoying improved robustness of reconfiguration (e.g., handover) against failure.

In view of the above modifications and variations, Figure 2 depicts a method performed by a first network node 14 configured to operate as a master network node for multi-connectivity operation of a wireless device 12 in accordance with particular embodiments. The method in some embodiments includes transmitting, from the first network node 12 to a candidate target node 18-1...18-N, a handover request message 20 that requests preparation of resources at the candidate target node 18-1...18-N for a handover of a wireless device 12 operating in multi connectivity with the first network node 14 as a master network node and a second network node 16 as a secondary network node (Block 200). The method may also include, after transmitting the handover request message 20, receiving from the candidate target node 18- 1...18-N a handover request acknowledge message 22 that informs the first network node 14 about prepared resources at the candidate target node 18-1...18-N for the handover (Block 210). The method may further include transmitting or refraining from transmitting a secondary node release request message 24 to the second network node 16 in response to receiving the handover request acknowledge message 22, depending respectively on whether the handover is not or is a conditional handover, wherein the secondary node release request message 24 requests release of resources for the wireless device 12 at the second network node 16 (Block 220).

In some embodiments, the method further comprises deciding whether to transmit the secondary node release request message 24 to the second network node 16 in response to receiving the handover request acknowledge message 22 or to refrain from transmitting the secondary node release request message 24 to the second network node 16 in response to receiving the handover request acknowledge message 24, based respectively on whether the handover is not or is a conditional handover. In this case, the transmitting or refraining is performed according to said deciding.

In any of the embodiments where the handover is a conditional handover, the transmitting or refraining may comprise refraining from transmitting the secondary node release request message 24 to the second network node 16 in response to receiving the handover request acknowledge message 22. This may mean that the first network node 14 instead waits to transmit the secondary node release request message 24 to the second network node 16 until the wireless device 12 executes the conditional handover. Such waiting may comprise waiting to transmit the secondary node release request message 24 to the second network node 16 until the first network node 12 receives a message 26 that indicates the wireless device 12 has executed the conditional handover. This message 26 may for example be a handover success message that indicates the wireless device 12 has successfully accessed the same or a different candidate target node for the handover (or has successfully access a cell of a candidate target node for the handover). As another example, the message 26 may be a context release message or a retrieve context request message. The message 26 in any event may be received in some embodiments from the wireless device 12 or from the same or a different candidate target node. Regardless, in any of the embodiments where the first network node 14 waits until receipt of the message 26, the method may further comprise, based on receiving the message 26, initiating a handover cancel procedure towards one or more other candidate target nodes of the handover.

In any of the embodiments above, the master network node may be a source master network node for the handover and the secondary network node may be a source secondary network node for the handover.

In any of the embodiments above, the secondary node release request message 24 may indicate a cause of the secondary node release request message 24 as being master cell group, MCG, mobility or master node mobility. Or, in other embodiments, the secondary node release request message 24 indicates a cause of the secondary node release request message 24 as being conditional MCG mobility or conditional master node mobility.

In any of the embodiments above, the method may further comprise receiving, from the second network node 16, a secondary node release request acknowledge message confirming the secondary node release request message 24 and/or confirming that the second network node 16 has released resources for the wireless device 12 at the second network node 16.

In any of the embodiments above, the method may further comprise, after or in conjunction with transmitting the secondary node release request message 24, receiving data from the second network node 16 and forwarding the data to the candidate target node.

Figure 3 depicts a method performed by a first network node 14 configured to operate as a master network node for multi-connectivity operation of a wireless device 12 in accordance with other particular embodiments. The method includes receiving a message 26 that indicates that a wireless device 12 operating in multi-connectivity has executed a conditional handover (Block 300). In some embodiments, the message 26 is a handover success message that indicates the wireless device 12 has successfully accessed a candidate target node for the conditional handover (or, more particularly, a cell of a candidate target node for the conditional handover). In other embodiments, the message 26 is a context release message or a retrieve context request message. Generally, then, the message 26 in some embodiments may be received from the wireless device 12 or from a candidate target node for the conditional handover. Regardless, the method may further include, based on receiving the message 26, transmitting a secondary node release request message 24 to a second network node 16 operating as a secondary network node for multi-connectivity operation of the wireless device 12, wherein the secondary node release request message 24 requests release of resources for the wireless device 12 at the second network node 16 (Block 310).

In any of these embodiments, the secondary node release request message 24 may indicate a cause of the secondary node release request message 24 as being master cell group, MCG, mobility or master node mobility. In other embodiments, the secondary node release request message 24 may indicate a cause of the secondary node release request message 24 as being conditional MCG mobility or conditional master node mobility.

In any of these embodiments, the master network node may be a source master network node for the conditional handover and the second network node may be a source secondary network node for the handover.

In any of these embodiments, the method may further comprise, based on receiving the message 26, initiating a handover cancel procedure towards one or more other candidate target nodes of the conditional handover.

In some embodiments, the method also includes receiving, from the second network node 16, a secondary node release request acknowledge message confirming the secondary node release request message 24 and/or confirming that the second network node 16 has released resources for the wireless device 12 at the second network node 16 (Block 320). Alternatively or additionally, the method may include, after or in conjunction with transmitting the secondary node release request message 24, receiving data from the second network node 16 and forwarding the data to the candidate target node 18-1...18-N (Block 330).

Note that the method in Figure 3 may be implemented separately from or in combination with the method in Figure 2. When implemented in combination, for example, the method in Figure 3 may further comprise steps 200, 210, and 220. In particular, the method in Figure 3 may further comprise transmitting, from the first network node 14 to a candidate target node, a handover request message 20 that requests preparation of resources at the candidate target node for the conditional handover. In this case, the method may also comprise, after transmitting the handover request message 20, receiving from the candidate target node a handover request acknowledge message 22 that informs the first network node 14 about prepared resources at the candidate target node for the conditional handover. The method may further comprise refraining from transmitting the secondary node release request message 24 to the second network node 16 in response to receiving the handover request acknowledge message 22, and instead waiting to transmit the secondary node release request message 24 to the second network node 16 until the first network node 14 receives the message 26 that indicates the wireless device 12 has executed the conditional handover.

Although not shown, other embodiments herein include a method performed by a first network node 14 configured to operate as a master network node for multi-connectivity operation of a wireless device 12. The method comprises receiving, from a second network node 16 operating as a secondary network node for multi-connectivity operation of the wireless device 12, a handover success message 26 that indicates the wireless device 12 has accessed a candidate target node for a conditional handover.

Embodiments herein also include corresponding apparatuses. Embodiments herein for instance include a network node (e.g., a first network node 14, a second network node 16, or a third network node) configured to perform any of the steps of any of the embodiments described above.

Embodiments also include a network node (e.g., a first network node 14, a second network node 16, or a third network node) comprising processing circuitry and power supply circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above. The power supply circuitry is configured to supply power to the network node.

Embodiments further include a network node (e.g., a first network node 14, a second network node 16, or a third network node) comprising processing circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above.

In some embodiments, the network node further comprises communication circuitry.

Embodiments further include a network node (e.g., a first network node 14, a second network node 16, or a third network node) comprising processing circuitry and memory. The memory contains instructions executable by the processing circuitry whereby the network node is configured to perform any of the steps of any of the embodiments described above.

More particularly, the apparatuses described above may perform the methods herein and any other processing by implementing any functional means, modules, units, or circuitry. In one embodiment, for example, the apparatuses comprise respective circuits or circuitry configured to perform the steps shown in the method figures. The circuits or circuitry in this regard may comprise circuits dedicated to performing certain functional processing and/or one or more microprocessors in conjunction with memory. For instance, the circuitry may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory may include program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein, in several embodiments. In embodiments that employ memory, the memory stores program code that, when executed by the one or more processors, carries out the techniques described herein. Figure 4 for example illustrates a network node 400 as implemented in accordance with one or more embodiments. The network node 400 may for example be the first network node 14 in Figure 1. As shown, the network node 400 includes processing circuitry 410 and communication circuitry 420. The communication circuitry 420 (e.g., radio circuitry) is configured to transmit and/or receive information to and/or from one or more other nodes, e.g., via any communication technology. Such communication may occur via one or more antennas that are either internal or external to the network node 400. The processing circuitry 410 is configured to perform processing described above, e.g., in Figure 2 and/or Figure 3, such as by executing instructions stored in memory 430. The processing circuitry 410 in this regard may implement certain functional means, units, or modules.

Those skilled in the art will also appreciate that embodiments herein further include corresponding computer programs.

A computer program comprises instructions which, when executed on at least one processor of an apparatus, cause the apparatus to carry out any of the respective processing described above. A computer program in this regard may comprise one or more code modules corresponding to the means or units described above.

Embodiments further include a carrier containing such a computer program. This carrier may comprise one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

In this regard, embodiments herein also include a computer program product stored on a non-transitory computer readable (storage or recording) medium and comprising instructions that, when executed by a processor of an apparatus, cause the apparatus to perform as described above.

Embodiments further include a computer program product comprising program code portions for performing the steps of any of the embodiments herein when the computer program product is executed by a computing device. This computer program product may be stored on a computer readable recording medium.

Additional embodiments will now be described. At least some of these embodiments may be described as applicable in certain contexts and/or wireless network types for illustrative purposes, but the embodiments are similarly applicable in other contexts and/or wireless network types not explicitly described.

Some embodiments herein are applicable to release of MR-DC during mobility for a UE operating in MR-DC. Here, the wireless device 12 in Figure 1 is exemplified as a UE operating in MR-DC. And the first network node 14 in Figure 1 is exemplified as a node operating as an MN for the UE, where the MN triggers a handover (reconfiguration with sync) for the UE. The simplest scenario is when the target MN decides not to continue the MR-DC operation with the incoming UE. In that case, an MN to ng-eNB/gNB Change procedure is used, as described in TS 37.340 V16.1.0. The MN to ng-eNB/gNB Change procedure is used to transfer UE context data from a source MN/SN to a target ng-eNB/gNB. Both the cases where the source MN and the target node belong to the same radio access technology (RAT) (i.e. they are both ng-eNBs or both gNBs) and the cases where the source MN and the target node belong to different RATs are supported. Inter-system HO from ng-eNB/gNB MN to eNB is also supported.

Figure 5 shows an example signalling flow for the MN to ng-eNB/gNB Change procedure according to some embodiments where the handover is a legacy, unconditional handover.

1. The source MN starts the MN to ng-eNB/gNB Change procedure by initiating the Xn Handover Preparation procedure, including both MCG and SCG configuration. This includes the source MN (S-MN) sending a Handover Request to the target ng-eNB/gNB of the Handover Preparation procedure.

2. The target ng-eNB/gNB sends a Handover Request Acknowledge to the S-MN. The target ng-eNB/gNB includes the field in the handover (HO) command which releases the SCG configuration, and may also provide forwarding addresses to the source MN.

3a-3c. If the resource allocation of the target ng-eNB/gNB was successful, the MN initiates the release of the source SN resources towards the source SN by transmitting an SN Release Request to the target ng-eNB/gNB, including a Cause indicating MCG mobility (Step 3a). The SN acknowledges the release request by sending an SN Release Request Acknowledge to the S-MN (Step 3b). If data forwarding is needed, the MN provides data forwarding addresses to the source SN by transmitting an Xn-U Address Indication to the S-SN (Step 3c). Reception of the SN Release Request message triggers the source SN to stop providing user data to the UE and, if applicable, to start data forwarding.

4. The MN triggers the UE to perform HO and apply the new configuration by transmitting an RRCConnectionReconfiguration to the UE. Upon receiving the new configuration, the UE releases the entire SCG configuration.

5/6. The UE synchronizes to the target ng-eNB/gNB. The UE in this regard performs a random access procedure with the target ng-eNB/gNB (Step 5). Upon completion of the random access procedure, the UE sends RRCConnectionReconfigurationComplete to the target ng- eNB/gNB (Step 6).

7a-7b. If the Packet Data Convergence Protocol (PDCP) termination point is changed for bearers using Radio Link Control (RLC) Acknowledged Mode (AM), the SN sends the SN Status Transfer to the S-MN (Step 7a), which the source MN sends then to the target ng- eNB/gNB (Step 7b).

8. If applicable, data forwarding takes place from the source side.

9a. The source SN sends the Secondary RAT Data Usage Report message to the source MN and includes the data volumes delivered to and received from the UE.

9b. The source MN sends the Secondary RAT Report message to the Access and Mobility Function (AMF) to provide information on the used NR/E-UTRA resource.

10-14. The target ng-eNB/gNB initiates the Path Switch procedure.

15. The target ng-eNB/gNB initiates the UE Context Release procedure towards the source MN.

16. Upon reception of the UE Context Release message from the MN, the source SN releases radio and C-plane related resources associated to the UE context. Any ongoing data forwarding may continue.

According to some embodiments, the SN release procedure in Steps 3a and 3b of Figure 5 is performed in MCG mobility as shown in Figure 6, as specified in 3GPP TS 38.423 v16.1.0. Note that MCG mobility may also be referred to as MN mobility, e.g., as in TS 38.423 V16.1.0.

As shown in Figure 6, the M-NG-RAN node initiated S-NG-RAN node Release procedure is triggered by the M-NG-RAN node to initiate the release of the resources for a specific UE. The procedure uses UE-associated signalling.

In Step 1, the M-NG-RAN node initiates the procedure by sending the S-NODE RELEASE REQUEST message. Upon reception of the S-NODE RELEASE REQUEST message the S-NG-RAN node shall stop providing user data to the UE.

If the S-NG-RAN node confirms the request to release S-NG-RAN node resources, it shall send the S-NODE RELEASE REQUEST ACKNOWLEDGE message to the M-NG-RAN node in Step 2.

If data forwarding is needed, the MN provides data forwarding addresses to the source SN. Reception of the SN Release Request message triggers the source SN to stop providing user data to the UE and, if applicable, to start data forwarding.

Some embodiments herein are similarly applicable to EN-DC. The procedures share some similarities in the case of EN-DC i.e. a UE operating in EN-DC with an LTE eNB as MN, and a UE operating in EN-DC with an LTE eNB as MN, and an NR gNB as SN. Figure 7 shows one example of the signaling flow for the MN to eNB Change procedure according to some embodiments where the handover is a legacy, unconditional handover.

The Master Node to eNB Change procedure is used to transfer context data from a source MN/SN to a target eNB.

1. The source MN starts the MN to eNB Change procedure by initiating the X2 Handover Preparation procedure, including both MCG and SCG configuration. This includes the source MN (S-MN) sending a Handover Request to the target eNB (T-eNB) of the Handover Preparation procedure. Note that the source MN may trigger the MN-initiated SN Modification procedure (to the source SN) to retrieve the current SCG configuration before step 1.

2. The target eNB sends a Handover Request Acknowledge to the S-MN. The target eNB includes the field in HO command which releases SCG configuration, and may also provide forwarding addresses to the source MN. 3a-3b. If the allocation of target eNB resources was successful, the MN initiates the release of the source SN resources towards the source SN, by transmitting an SN Release Request to the target eNB, including a Cause indicating MCG mobility (Step 3a). The SN acknowledges the release request by sending an SN Release Request Acknowledge to the S- MN (Step 3b). If data forwarding is needed, the MN provides data forwarding addresses to the source SN. Reception of the SgNB Release Request message triggers the source SN to stop providing user data to the UE and, if applicable, to start data forwarding.

4. The MN triggers the UE to apply the new configuration by transmitting an RRCConnectionReconfiguration to the UE. Upon receiving the new configuration, the UE releases the entire SCG configuration.

5/6. The UE synchronizes to the target eNB. The UE in this regard performs a random access procedure with the target eNB (Step 5). Upon completion of the random access procedure, the UE sends RRCConnectionReconfigurationComplete to the target eNB (Step 6).

7a-7b. For SN terminated bearers using RLC AM, the SN sends the SN Status Transfer (Step 7a), which the source MN sends then to the target eNB (Step 7b).

8. If applicable, data forwarding takes place from the source side.

9a. The source SN sends the Secondary RAT Data Usagee Report message to the source MN and includes the data volumes delivered to and received from the UE over the NR radio for the related E-RABs. Note that the order the SN sends the Secondary RAT Data Usage Report message and performs data forwarding with MN is not defined. The SN may send the report when the transmission of the related bearer is stopped.

9b. The source MN sends the Secondary RAT Report message to MME to provide information on the used NR resource.

10-14. The target eNB initiates the S1 Path Switch procedure.

15. The target eNB initiates the UE Context Release procedure towards the source MN.

16. Upon reception of the UE Context Release message, the SN releases radio and C- plane related resources associated to the UE context. Any ongoing data forwarding may continue.

Note that inter-system HO from E-UTRA with EN-DC configuration to NR or to E-UTRA connected to 5GC is also supported.

By contrast, the signaling flows shown in Figures 5 and 7 for an unconditional handover may differ in some embodiments for a conditional handover. A conditional handover (also called ‘early handover command’) may aim at improving the robustness at handover and to decrease the interruption time at handover. In order to avoid the undesired dependence on the serving radio link upon the time (and radio conditions) where the UE should execute the handover, some embodiments provide RRC signaling for the handover to the UE earlier than for a conventional, unconditional handover. Some embodiments achieve this by associating the HO command with a condition e.g. based on radio conditions possibly similar to the ones associated to an A3 event, where a given neighbour becomes X db better than target. As soon as the condition is fulfilled, the UE executes the handover in accordance with the provided handover command.

Such a condition could e.g. be that the quality of the target cell or beam becomes X dB stronger than the the serving cell. The threshold Y used in a preceding measurement reporting event should then be chosen lower than the one in the handover execution condition. This allows the serving cell to prepare the handover upon reception of an early measurement report and to provide the RRCConnectionReconfiguration with mobilityControllnfo at a time when the radio link between the source cell and the UE is still stable. The execution of the handover is done at a later point in time (and threshold) which is considered optimal for the handover execution.

A conditional handover in this regard may more particularly be defined according to some embodiments as described in stage 2, 3GPP TS 38.300 v16.0.0 in a new chapter 9.2.3.X (see also CR R2-2001748). A Conditional Handover (CHO) in this case is defined as a handover that is executed by the UE when one or more handover execution conditions are met. The UE starts evaluating the execution condition(s) upon receiving the CHO configuration, and stops evaluating the execution condition(s) once the execution condition(s) is met.

The CHO configuration contains the configuration of CHO candidate cell(s) generated by the candidate gNB(s) and execution condition(s) generated by the source gNB. An execution condition may consist of one or two trigger condition(s) (e.g., CHO events A3/A5). In some embodiments, only a single reference signal (RS) type is supported and at most two different trigger quantities can be configured simultaneously for the evaluation of CHO execution condition of a single candidate cell. For example, Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ) may be simultaneously configured trigger quantities. Or, RSRP and Signal-To-lnterference-plus-Noise-Ratio (SINR) may be simultaneously configured trigger quantities.

The UE maintains the connection with the source gNB after receiving the CHO configuration, and starts evaluating the CHO execution conditions for the candidate cell(s). If at least one CHO candidate cell satisfies the corresponding CHO execution condition, the UE detaches from the source gNB, applies the stored corresponding configuration for that selected candidate cell, synchronises to that candidate cell and completes the RRC handover procedure by sending RRCReconfigurationComplete message to the target gNB. The UE releases stored CHO configurations after successful completation of RRC handover procedure.

Some embodiments address an issue that exists when CHO (MCG) works together with MR-DC, i.e. receive CHO when MR-DC is configured, and receive SCG addition when CHO condition is configured. So, a UE operating in MR-DC may receive a CHO configuration including an RRCReconfiguration per target candidate MN. And a UE configured with CHO (i.e. monitoring conditions for a target candidate) received an SCG addition. An issue exists as to whether a target candidate MN configuration could include an SCG configuration. One possible resolution of this issue is that the RRCReconfiguration prepared by an MN target candidate cannot contain an SCG configuration.

A source MN may decide to handover a UE operating in MR-DC to a target MN e.g. UE operating in EN-DC or NR-DC. In that case, the Source MN (S-MN) sends a HANDOVER REQUEST message to the target MN (T-MN) including the MCG and SCG configurations. Upon reception, the target MN may create the RRCReconfiguration and include the indication to the UE to release SCG configurations (e.g. an mrdc-SecondaryCellGroupConfig set to release) and a forwarding address to the Source MN in a HANDOVER REQUEST ACKNOLWEDGE to the Source MN. For Conditional Handover, the HANDOVER REQUEST from the Source MN may include additional information indicating to a target candidate MN that this is a CHO and not an ordinary handover, so the target MN is aware that the UE may not come immediately.

At the source MN, if the same procedure as ordinary HO continues to be used for CHO too, upon reception of the HANDOVER REQUEST ACKNOWLEDGE, the Source MN would release the SN upon configuring CHO i.e. it would perform step 3a in Figure 5 and Figure 7.

This would mean the UE would not be configured with CHO while in MR-DC, since MR-DC would be released when the UE is configured with CHO. This is not good in terms of improving data rates, and at the same time, being able to keep robustness of the connection with CHO configuration at the UE.

Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges.

In some embodiments, during CHO preparation, the Source MN receives a HANDOVER REQUEST ACKNOWLEDGE message from at least one target candidate MN in response to a HANDOVER REQUEST for CHO and refrains from transmitting an SN RELEASE REQUEST message to the Source SN (S-SN), e.g., at least as or in response to the HANDOVER REQUEST ACKNOWLEDGE message. The Source MN may instead wait to transmit the SN RELEASE REQUEST message to the Source SN until actual execution of the CHO, e.g., as indicated by a HANDOVER SUCCESS message.

For example, during CHO execution, the Source MN in some embodiments receives a second message (e.g. HANDOVER SUCCESS) from one of the target candidate nodes, i.e., target candidate MN(s) (for which CHO has been configured). The Source MN may then transmit an SN RELEASE REQUEST message to a second network node, e.g., operating as a Source SN (S-SN). The Source MN may also receive an SN RELEASE REQUEST ACKNOWLEDGE message from the second network node operating as a Source SN (S-SN). In some embodiments, the Source MN determines if data forwarding is needed (e.g. late data forwarding). If data forwarding is needed, the Source MN initiates an address indication procedure.

For example, some embodiments may be implemented by changing the timing with which Steps 3a-3b performed in Figures 5 and 7. In particular, in the case that the handover is a conditional handover, Steps 3a-3b in Figures 5 and 7 may be performed after the Source MN receives an indication that the UE has successfully attached to one of the potential target ng- eNB/gNB, i.e. , after Step 6. These embodiments may be implemented for instance by specifying such changes in the 3GPP TS 38.423 specification with regard to the Handover Success procedure.

Certain embodiments may provide one or more of the following technical advantage(s). Some embodiments enable a UE operating in MR-DC to be configured with Conditional Reconfiguration (e.g. Conditional Handover - CHO). In other words, a Source MN would be able to request CHO for target candidates, without necessarily releasing SN resources for the UE at the CHO configuration (i.e. refraining until CHO execution). That would increase UE data rates as UEs may continue to operate in MR-DC and, at the same time, have the possibility to improve the UE’s robustness, as the UE would be configured with CHO.

Thanks to some embodiments herein it is also possible to start data forwarding from the Source SN when CHO is being executed. That would reduce packet losses in CHO scenarios where the UE is configured with MR-DC.

Generally, then, some embodiments herein include methods performed by a first network node 14 in the context of CHO preparation and CHO execution for a UE. These embodiments refer to a first network node 14, a second network node 16, and a third network node 18. The UE exemplifies the wireless device 12 in Figure 1, and accordingly will be referred to as UE 12.

The first network node 14 may correspond to (e.g. operate as) one of the following: a Source Master Node (MN), S-MN, Source gNodeB, source eNodeB, Source NG-RAN node, an M-NG-RAN node indicating a gNodeB (e.g. connected to 5GC) operating in MR-DC as an MN, and associated to NG-RAN; an M-NG-RAN node indicating an ng-eNodeB (e.g. connected to 5GC) operating in MR-DC as an MN, and associated to NG-RAN; an LTE eNodeB connected to EPC operating a MeNodeB or MeNB.

The second network node 16 may correspond (e.g. operate as) one of the following: to a Source Secondary Node (SN), S-SN, Source Secondary gNodeB (SgNB), source Secondary eNodeB (SeNB), Secondary Source NG-RAN node, etc.

The third network node 18 may correspond to (e.g. operate as) a target candidate node, candidate target node, target MN (T-MN), target node, target candidate gNodeB, target candidate eNodeB, target candidate NG-RAN node, candidate target gNodeB, candidate target eNodeB, candidate target NG-RAN node, target gNodeB, target eNodeB, target NG-RAN node; A target candidate NG-RAN node indicating a gNodeB (e.g. connected to 5GC) associated to NG-RAN; A target candidate NG-RAN node indicating an ng-eNodeB (e.g. connected to 5GC) associated to NG-RAN; A target candidate LTE eNodeB connected to EPC, possibly a target candidate MeNodeB or target candidate MeNB. Note here that the terms target, target node, target candidate node, target candidate, candidate target node should be interpreted as synonyms, unless explicitly said otherwise.

In an EN-DC configuration, for example, the first network node 14 corresponds to a Source eNodeB (S-eNB), the second network node 16 corresponds to an NR gNodeB operating as Secondary S-gNodeB (SgNB), and the third network node 18 corresponds to a Target eNodeB.

In an NR-DC configuration, for example, the first network node 14 corresponds to a Source gNodeB (S-gNB), the second network node 16 corresponds to an NR gNodeB operating as Secondary S-gNodeB (SgNB), and the third network node 18 corresponds to a Target gNodeB.

Figure 8 shows that, with respect to CHO preparation, some embodiments herein include a method performed at a first network node 14 operating as Source MN.

In some embodiments, an optional step of the method (Step 800) includes determining to configure a UE 12 with a conditional reconfiguration (e.g. Conditional Handover - CHO), wherein the UE 12 is operating in MR-DC with the first network node 14 as Master Node (e.g. Source MN, S-MN). The determination may be based on measurement reports received from the UE 12 at the Source MN, including measurements for cells associated to neighbour nodes (e.g. neighbour gNodeB(s)) that may be target candidate nodes for CHO.

Regardless, the method may include transmitting a HANDOVER REQUEST message to a third network node 18 (which is a target candidate node, e.g. a target gNodeB) including an indication that the procedure is for CHO (Step 810). This HANDOVER REQUEST message may exemplify the handover request message 20 in Figure 1. In one embodiment, the first network node 14 transmits a HANDOVER REQUEST message to a single target candidate including an indication that the procedure is for CHO. For example, a target candidate may have one target cell candidate associated to it. In another embodiment, the first network node 14 transmits HANDOVER REQUEST messages to a single target candidate including an indication that the procedure is for CHO. For example, a target candidate may have multiple target cells candidates associated to it. In that case there may be one HANDOVER REQUEST message transmitted for each target cell candidate. In yet another embodiment, the first network node 14 transmits HANDOVER REQUEST messages to multiple target candidates including an indication that the procedure is for CHO. For example, a target candidate may have multiple target cells candidates associated to it. In that case there may be one HANDOVER REQUEST message transmitted for each target cell candidate. And, there may be multiple candidate cells in different target candidate nodes.

Regardless, the method may also include receiving a HANDOVER REQUEST ACKNOWLEDGE message from the third network node 18 (which is a target candidate node, e.g. a target gNodeB) (Step 820). This HANDOVER REQUEST ACKNOWLEDGE message may exemplify the handover request ACK message 22 in Figure 1. In one embodiment, the first network node 14 receives one HANDOVER REQUEST ACKNOWLEDGE from a single target candidate. For example, a target candidate may have one target cell candidate associated to it. In another embodiment, the first network node 14 receives HANDOVER REQUEST ACKNOWLEDGE messages from a single target candidate node. For example, a target candidate may have multiple target cells candidates associated to it. In that case there may be one HANDOVER REQUEST ACKNOWLEDGE message received for each target cell candidate. In yet another embodiment, the first network node 14 receives HANDOVER REQUEST ACKNOWLEDGE messages from multiple target candidates. For example, a target candidate may have multiple target cells candidates associated to it. In that case there may be one HANDOVER REQUEST ACKNOWLEDGE message received for each target cell candidate. And, there may be multiple candidate cells in different target candidate nodes.

The method may further include refraining from transmitting an SN RELEASE REQUEST message to a second network node 16 operating as Source Secondary Node SN (S-SN) (Step 830). This SN RELEASE REQUEST message may exemplify the secondary node release request message 24 in Figure 1. In one embodiment, the method comprises the refraining to trigger (i.e. refraining to initiate or refraining to start) an SN release procedure e.g. upon reception of the HANDOVER REQUEST ACKNOWLEDGE. The SN release procedure may correspond to an MeNB initiated SgNB Release procedure as defined in TS 36.423, v16.1.0, sub-clause 8.7.9, e.g., in the case the MN is an LTE node and the SN is an NR node (for a UE 12 operating in EN-DC). In other embodiments, the SN release procedure may correspond to an M-NG-RAN node initiated S-NG-RAN node Release procedure as defined in TS 38.423, v16.1.0, sub-clause 8.3.6, e.g., in the case the MN is an NR node and the SN is an NR node (for a UE operating in NR-DC).

In one embodiment, the refraining action in Step 830 is performed upon determining that the HANDOVER REQUEST ACKNOWLEDGE has been received in response to a HANDOVER REQUEST for a conditional reconfiguration (e.g. Conditional Handover).

The SN RELEASE REQUEST message may be at least one of the following messages. The SN RELEASE REQUEST message may correspond to an SGNB RELEASE REQUEST message as defined in TS 36.423, v16.1.0, e.g., in the case the MN is an LTE node and the SN is an NR node (for a UE operating in EN-DC). In other embodiments, the SN RELEASE REQUEST message may correspond to an S-NODE RELEASE REQUEST message as defined in TS 38.423, v16.1.0, e.g., in the case the MN is an NR node and the SN is an NR node (for a UE 12 operating in NR-DC).

In one embodiment, if the HANDOVER REQUEST ACKNOWLEDGE has been received in response to a HANDOVER REQUEST for a legacy reconfiguration (e.g. Handover), the method may comprise initiating the SN release procedure (if the UE 12 is operating in MR-DC). Else, if the HANDOVER REQUEST ACKNOWLEDGE has been received in response to a HANDOVER REQUEST for a conditional reconfiguration (e.g. Conditional Handover), the method may comprise refraining from initiating the SN release procedure (if the UE 12 is operating in MR-DC).

In one embodiment, the method may comprise monitoring for the reception of a first message from one of the target candidates (Step 840). This first message may exemplify the message 26 in Figure 1 that indicates conditional handover execution. Upon reception of that first message, the method may comprise initiating the SN release procedure (if the UE 12 is operating in MR-DC) (Step 850). The reason to add “if the UE is operating in MR-DC” here is that the UE 12 may have been reconfigured after the CHO configuration i.e. upon CHO execution the UE 12 may not be any longer operating in MR-DC.

In one embodiment, the method comprises the first network node 14 (e.g. Source MN, S-MN, which may be an LTE eNodeB operating as MN) configuring the UE with Conditional Reconfiguration, such as Conditional Handover (CHO). In other words, the first network node 14 transmits to the UE 12 an RRC Reconfiguration message containing a CHO configuration e.g. the field conditionalReconfiguration of IE ConditionalReconfiguration to be defined in TS 38.331 V16.0.0.

Generally, then, the method at the first network node 14 may comprise: (i) transmitting an SN RELEASE REQUEST message to a second network node 16 operating as a Source SN (S-SN), e.g., a Source Secondary gNodeB (Source SgNB); and (ii) receiving an SN RELEASE REQUEST ACKNOWLEDGE message from the second network node 16 operating as a Source SN (S-SN) e.g., a Source Secondary gNodeB (Source SgNB).

In some embodiments, if data forwarding is needed, the first network node 14 (e.g. Source MN) initiates an address indication procedure with the second network node 16. Although not shown, then, in some embodiments, the method may include determining that late data forwarding is to be performed. In some embodiments, the method may include receiving an SN Status Transfer from the second network node 16 operating as Source SN. In some embodiments, the method may include transmitting an SN Status Transfer to the third network node 18 (e.g. target candidate node, target gNodeB). In some embodiments, the method may include receiving forwarded data from the second network node 16 operating as Source SN. In some embodiments, the method may include forwarding data to the third network node 18 (e.g. target gNodeB).

Figure 9 shows a corresponding signaling flow for the method in Figure 8 according to some embodiments. Step 1 in Figure 9 corresponds to Step 800 in Figure 8. Steps 2A-2B in Figure 9 correspond to Steps 810 and 820 in Figure 8. Step 3 in Figure 9 corresponds to Step 830 in Figure 8. And Step 6 in Figure 9 corresponds to Step 840 in Figure 8.

Some embodiments alternatively or additionally to those exemplifed for CHO preparation in Figures 8 and 9 include another method performed at the first network node 14 operating as Source MN. This method relates to CHO execution, as exemplified in Figures 10 and 11 according to some embodiments. CHO execution occurs after CHO preparation, e.g., such that the steps in Figures 10 and 11 may be performed after the steps in Figures 8 and 9.

The method may comprise receiving a second message from the third node18, which is a target candidate node (e.g., target candidate gNodeB for which CHO has been configured) (Step 1000 in Figure 10). This second message may exemplify the message 26 in Figure 1.

In one embodiment, as shown in Step 9 of Figure 11 , the second message is HANDOVER SUCCESS message. The HANDOVER SUCCESS message is received as part of the Handover Success procedure and is used during a conditional handover or a Dual Active Protocol Stack (DAPS) handover, to enable a target NG-RAN node to inform the source NG- RAN node that the UE has successfully accessed the target NG-RAN node. In other words, the reception of the HANDOVER SUCCESS message from a specific target NG-RAN (i.e. one of the target candidate MN(s)) indicates that the UE 12 has successfully accessed that specific target NG-RAN node. Figure 12 shows one example of successful operation of the HANDOVER SUCCESS procedure.

If late data forwarding is configured, the source NG-RAN node shall start data forwarding using the tunnel information related to the global target cell ID provided in the HANDOVER SUCCESS message. In this particular case where the UE 18 is in MR-DC when CHO is executed and notified via the HANDVOER SUCCESS message, data forwarding may involve the Source SN node (e.g. STATUS TRANSFER, data forwarding from the Source SN to the Source MN, etc.).

When the source NG-RAN node receives the HANDOVER SUCCESS message, it shall consider all other CHO preparations accepted for this UE 12 in the target NG-RAN node as cancelled and may initiate Handover Cancel procedure towards other candidate target NG-RAN nodes for this UE 12, if any, and may initiate the M-NG-RAN node initiated S-NG-RAN node Release procedure if the UE 12 was configured with dual connectivity, as described in TS 37.340 V16.1.0.

The below table shows an example of the HANDOVER SUCCESS message, to be possibly defined in TS 38.423. This message is sent by the target NG-RAN node to the source NG-RAN node to indicate the successful access of the UE toward the target NG-RAN node.

Direction: target NG-RAN node ® source NG-RAN node.

In another embodiment, the second message may be one of the following: UE CONTEXT RELEASE; or RETRIEVE UE CONTEXT REQUEST.

In some embodiments, the second message is NOT a HANDOVER REQUEST ACKNOLWEDGE message

In some embodiments, the second message is any message indicating to the Source MN that Conditional Handover has been executed. In one embodiment, the second message is any message indicating to the Source MN that Conditional Handover has been successfully executed.

The second message may be received from the UE 12. Or, the second message may be received from a target candidate node.

In any event, the method in Figure 10 may comprise transmitting an SN RELEASE REQUEST message to a second network node 16 operating as a Source SN (S-SN), e.g., a Source Secondary gNodeB (Source SgNB) (Step 1010 in Figure 10 and Step 11 in Figure 11).

In one embodiment, for example, the method comprises the initiation of the SN release procedure towards the Source SN e.g. upon reception of the second message, such as the HANDOVER SUCCESS message from a target candidate MN. The reception of the second message indicates a CHO execution in the target candidate that transmits the second message to the first network node 14. In one embodiment, upon reception of the HANDOVER SUCCESS message, the first network node 14 initiates the release of the source SN resources towards the source SN including a Cause indicating MCG mobility.

If data forwarding is needed, the first network node 14 provides data forwarding addresses to the source SN. Reception of the SN Release Request message triggers the source SN to stop providing user data to the UE and, if applicable, to start data forwarding.

In one embodiment the first network node 14 (e.g. S-MN) indicates to the second network node 16 (e.g. Source SN, S-SN) a cause value for the SN RELEASE REQUEST indicating that the release is triggered due to a conditional handover. The cause value may be at least one of the following.

The cause value may be “MN mobility”. This may be used in case the S-SN does not need to perform any distinction between a CHO and a legacy HO as cause value, e.g., when transmitting the SN RELEASE REQUEST ACKNWLEDGE.

The cause value may be “Conditional MN mobility”. This may be used in case the S-SN needs to perform a distinction between a CHO and a legacy HO as cause value, e.g., when transmitting the SN RELEASE REQUEST ACKNWLEDGE including specific information.

The cause value may be “MCG mobility”. This may be used in case the S-SN does not need to perform any distinction between a CHO and a legacy HO as cause value, e.g., when transmitting the SN RELEASE REQUEST ACKNWLEDGE.

The cause value may be “Conditional MCG mobility”. This may be used in case the S- SN needs to perform a distinction between a CHO and a legacy HO as cause value, e.g., when transmitting the SN RELEASE REQUEST ACKNWLEDGE including specific information.

In one embodiment, if the S-NG-RAN node provides data forwarding related information (which is received in the first network node 14, S-MN) in the S-NODE RELEASE REQUEST ACKNOWLEDGE message for quality of service (QoS) flows mapped to DRBs configured with an SN terminated bearer option in the Protocol Data Unit (PDU) Sessions To Be Released List - SN terminated IE, the M-NG-RAN node may decide to provide data forwarding addresses to the S-NG-RAN node and trigger the Xn-U Address Indication procedure, as specified in TS 37.340 v16.1.0 for CHO.

If data forwarding is needed, the first network node 14 (e.g. Source MN) initiates an address indication procedure with the second network node 16 (Step 13 in Figure 11). In one embodiment, the address indication procedure is an XN-U Address Indication procedure, as defined in TS 38.423 v16.1.0 (e.g. in sub-clause 8.2.6).

In one embodiment, the first network node 14 corresponds to an M-NG-RAN node.

In one embodiment the first network node 12 indicates to the Source SN its own forwarding address (or addresses) during the address indication procedure.

In one embodiment, the first network node 12 (e.g. M-NG-RAN node) transmits an XN-U ADDRESS INDICATION message (Step 14 in Figure 11).

For MR-DC with 5GC, the Xn-U Address Indication procedure is used to provide forwarding addresses and Xn-U bearer address information for completion of setup of SN terminated bearers from the M-NG-RAN node to the S-NG-RAN node as specified in TS 37.340 v16.1.0. In the context of some embodiments, this message is sent by the M-NG-RAN node to provide either data forwarding or Xn-U bearer address information for SN terminated bearers to the S-NG-RAN node.

Note that, before the reception of the Xn-U Address indication the S-SN cannot transmit packets to the S-MN, e.g., in case packets come from the User Plane Function (UPF) to the S- SN, for SN-terminated bearers. Hence, thanks to the GPRS Tunneling Protocol User Plane (GTP-U) tunnel endpoints present in Xn-U Address indication, the S-SN can perform data forwarding to the S-MN. And, for late data forwarding, that needs to be done upon the CHO execution, i.e. , after the S-MN receives the HANDOVER SUCCESS message.

In some embodiments, the method also comprises determining that Late Data Forwarding (LDF) is to be performed (Step 1030 in Figure 10). In one embodiment, that is determined based on a configuration e.g. provided from Operation and Maintenance (OAM) system.

In some embodiments, the method comprises receiving an SN Status Transfer from the second network node operating as Source SN (Step 1040 in Figure 10). The Source MN receives from the S-SN the uplink PDCP SN and Hyper Frame Number (HFN) receiver status and the downlink PDCP SN and HFN transmitter status, for each respective DRB of the S-SN DRB configuration for which PDCP SN and HFN status preservation applies. The Source MN receives the SN STATUS TRANSFER message from the S-SN at the time point when it considers the transmitter/receiver status to be frozen.

In some embodiments, the method comprises transmitting an SN Status Transfer to the third network node (e.g. target candidate node, target gNodeB) (Step 1050 in Figure 10). The method may also comprise forwarding data to the third network node (e.g. target gNodeB) (Step 1060 in Figure 10). The method may further comprise receiving forwarded data from the second network node operating as Source SN (Step 1070 in Figure 10). In one embodiment, if the late data forwarding is applied, the first network node 14 (e.g. source MN) initiates data forwarding once it knows which target MN the UE 12 has successfully accessed. In that case the behavior of the Conditional Handover data forwarding follows the same behavior as defined in 9.2.3.2.3 for the intra-system handover data forwarding, except the behaivor for DRBs configured with DAPS Handover. In another embodiment, the source MN only starts data forwarding towards the target MN (after reception of HANDOVER SUCCESS) once it gets SN STATUS TRANSFER from the S-SN.

Embodiments herein also include a method performed at a second network node 16 operating as Source SN. As shown in Figure 13, the method comprises (e.g. CHO execution) receiving an SN RELEASE REGUEST message from the first network node 14 operating as a Source MN (S-MN) (1300). This SN RELEASE REGUEST message is an example of the secondary node release request message 24 in Figure 1. In one embodiment, the method comprises the initiation of the SN release procedure by the first network node 14 towards the Source SN e.g. upon reception by the first network node 14 of the second message, such as the HANDOVER SUCCESS message from a target candidate. The reception of the second message by the first network node 14 indicates a CHO execution in the target candidate that transmits the second message to the first network node 14. In one embodiment, upon reception of the is HANDOVER SUCCESS message, the first network node 14 initiates the release of the source SN resources towards the source SN including a Cause indicating MCG mobility.

In one embodiment, the reception of the SN RELEASE REQUEST message triggers the source SN to stop providing user data to the UE 12 and, if applicable, to start data forwarding.

The SN acknowledges the release request in some embodiments. If data forwarding is needed, the first network node 14 provides data forwarding addresses to the source SN. Reception of the SN Release Request message triggers the source SN to stop providing user data to the UE and, if applicable, to start data forwarding.

In some embodiments, then, the method further comprises transmitting an SN RELEASE REQUEST ACKNOWLEDGE message to the first network node operating as a Source MN (S-MN) (Step 1310). The transmission of the SN RELEASE REQUEST ACKNOWLEDGE confirms that the SN resources have been released. In one embodiment, the second network node 16 (e.g. an S-NG-RAN node) provides data forwarding related information (which is received in the first network node 14, S-MN) in the S-NODE RELEASE REQUEST ACKNOWLEDGE message for QoS flows mapped to DRBs configured with an SN terminated bearer option in the PDU Sessions To Be Released List - SN terminated IE. The M-NG-RAN node may decide to provide data forwarding addresses to the S-NG-RAN node and trigger the Xn-U Address Indication procedure, as specified in TS 37.340 v16.1.0 for CHO. In one embodiment, that sub-step of including data forwarding information is only performed if late data forwarding for the SN is configured (e.g. request in the SN Release Request, etc.).

In some embodiments, the method also comprises receiving an Xn-U Address Indication from the first network node operating as a Source MN (S-MN) (Step 1320). In this message, the Source MN provides data forwarding addresses to the source SN. Upon reception of the XN-U ADDRESS INDICATION message, in case of data forwarding, the second network node (e.g. S-NG-RAN node) should initiate data forwarding by forwarding pending DL user data to the indicated Transport Network Layer (TNL) addresses (Step 1330). In case of completion of Xn-U bearer establishment for SN terminated bearers, the S-NG-RAN node may start delivery of user data to the indicated TNL address. If the XN-U ADDRESS INDICATION message includes the DRB IDs taken into use IE, the S-NG-RAN node shall, if applicable, act as specified in TS 37.340 V16.1.0.

In some embodiments, then, the method may include determining that data forwarding is needed, and/or determining that late data forwarding is to be performed (Step 1325).

In some embodiments, the method may include transmitting an SN Status Transfer to the first network node 14 operating as Source MN (Step 1340). The S-SN transfers the uplink PDCP SN and HFN receiver status and the downlink PDCP SN and HFN transmitter status from the S-SN to the S-MN, for each respective DRE3§ of the S-SN DRB configuration for which PDCP SN and HFN status preservation applies. The S-SN initiates the procedure by stop assigning PDCP SNs to downlink SDUs and stop delivering UL SDUs towards the 5GC and sending the SN STATUS TRANSFER message to the S-MN node at the time point when it considers the transmitter/receiver status to be frozen.

In some embodiments, the method may include forwarding data to the first network node 14 (e.g. Source gNodeB, Source MN). This is DL data the S-SN may still be receiving from the UPF or DL data that it may still be receiving from the UE 12.

In some embodiments, the method may include the S-SN being notified that CHO is being configured at the UE 12 (Step 1350). The S-SN receives a message from the S-MN (e.g. SN REQUEST RELEASE message) with an indication that this is being triggered because the UE 12 has been configured with CHO. In that case, upon reception, the Source SN does not release the SN resources, but it gets prepared to do so (e.g. upon reception of another SN REQUEST RELEASE message), and transmits to the Source MN an SN REQUEST RELEASE ACKNOLWEDGE.

Consider now an example of possible implementations in 3GPP specifications. Embodiments herein may require changes in the TS 38.423 specifications, such as in the

Handover Success procedure, as follows:

_{*********************************************************************************************}

8.2. A Handover Success

8.2.A.1 General

The Handover Success procedure is used during a conditional handover or a DAPS handover, to enable a target NG-RAN node to inform the source NG-RAN node that the UE has successfully accessed the target NG-RAN node.

The procedure uses UE-associated signalling.

Figure 12 shows successful Operation for the Handover Success procedure. The target NG-RAN node initiates the procedure by sending the HANDOVER SUCCESS message to the source NG-RAN node.

If late data forwarding was configured for this UE, the source NG-RAN node shall start data forwarding using the tunnel information related to the global target cell ID provided in the HANDOVER SUCCESS message.

When the source NG-RAN node receives the HANDOVER SUCCESS message, it shall consider all other CHO preparations accepted for this UE in the target NG-RAN node as cancelled and may initiate Handover Cancel procedure towards other candidate target NG-RAN nodes for this UE, if any, and may initiate the M-NG-RAN node initiated S-NG-RAN node Release procedure if the UE was configured with dual connectivity, as described in TS 37.340 V16.1.0.

Interactions with other procedures

If a CONDITIONAL HANDOVER CANCEL message was received for this UE prior the reception of the HANDOVER SUCCESS message, the source NG-RAN node shall consider that the UE successfully executed the handover.

Some embodiments are described in scenarios where a UE is configured with Multi- Radio Dual Connectivity (MR-DC) when it receives a conditional handover (CHO) configuration. The embodiments described herein are focused on NR-DC (i.e. when both master and secondary node are NR gNBs), but the embodiments are equally applicable to other DC scenarios (e.g. NE-DC, (NG)EN-DC and LTE DC, where NE-DC stands for NR-E-UTRA DC).

Embodiments herein have been described with the term Conditional Handover (CHO) most of the time. Other terms may be considered as synonyms such as conditional reconfiguration, or Conditional Configuration (since the message that is stored and applied upon fulfillment of a condition is an RRCReconfiguration or RRCConnectionReconfiguration).

The principle for the configuration is the same with configuring triggering/execution condition(s) and a reconfiguration message to be applied when the triggering condition(s) are fulfilled.

Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in Figure 14. For simplicity, the wireless network of Figure 14 only depicts network 1406, network nodes 1460 and 1460b, and WDs 1410, 1410b, and 1410c. In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node 1460 and wireless device (WD) 1410 are depicted with additional detail. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices’ access to and/or use of the services provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type of communication, telecommunication, data, cellular, and/or radio network or other similar type of system. In some embodiments, the wireless network may be configured to operate according to specific standards or other types of predefined rules or procedures. Thus, particular embodiments of the wireless network may implement communication standards, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), Narrowband Internet of Things (NB-loT), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless local area network (WLAN) standards, such as the IEEE 802.11 standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards.

Network 1406 may comprise one or more backhaul networks, core networks, IP networks, public switched telephone networks (PSTNs), packet data networks, optical networks, wide-area networks (WANs), local area networks (LANs), wireless local area networks (WLANs), wired networks, wireless networks, metropolitan area networks, and other networks to enable communication between devices.

Network node 1460 and WD 1410 comprise various components described in more detail below. These components work together in order to provide network node and/or wireless device functionality, such as providing wireless connections in a wireless network. In different embodiments, the wireless network may comprise any number of wired or wireless networks, network nodes, base stations, controllers, wireless devices, relay stations, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the wireless network to enable and/or provide wireless access to the wireless device and/or to perform other functions (e.g., administration) in the wireless network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and may then also be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS). Yet further examples of network nodes include multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As another example, a network node may be a virtual network node as described in more detail below. More generally, however, network nodes may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a wireless device with access to the wireless network or to provide some service to a wireless device that has accessed the wireless network.

In Figure 14, network node 1460 includes processing circuitry 1470, device readable medium 1480, interface 1490, auxiliary equipment 1484, power source 1486, power circuitry 1487, and antenna 1462. Although network node 1460 illustrated in the example wireless network of Figure 14 may represent a device that includes the illustrated combination of hardware components, other embodiments may comprise network nodes with different combinations of components. It is to be understood that a network node comprises any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Moreover, while the components of network node 1460 are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node may comprise multiple different physical components that make up a single illustrated component (e.g., device readable medium 1480 may comprise multiple separate hard drives as well as multiple RAM modules).

Similarly, network node 1460 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node 1460 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeB’s. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node 1460 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate device readable medium 1480 for the different RATs) and some components may be reused (e.g., the same antenna 1462 may be shared by the RATs). Network node 1460 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1460, such as, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1460.

Processing circuitry 1470 is configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being provided by a network node. These operations performed by processing circuitry 1470 may include processing information obtained by processing circuitry 1470 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Processing circuitry 1470 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 1460 components, such as device readable medium 1480, network node 1460 functionality. For example, processing circuitry 1470 may execute instructions stored in device readable medium 1480 or in memory within processing circuitry 1470. Such functionality may include providing any of the various wireless features, functions, or benefits discussed herein. In some embodiments, processing circuitry 1470 may include a system on a chip (SOC).

In some embodiments, processing circuitry 1470 may include one or more of radio frequency (RF) transceiver circuitry 1472 and baseband processing circuitry 1474. In some embodiments, radio frequency (RF) transceiver circuitry 1472 and baseband processing circuitry 1474 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1472 and baseband processing circuitry 1474 may be on the same chip or set of chips, boards, or units

In certain embodiments, some or all of the functionality described herein as being provided by a network node, base station, eNB or other such network device may be performed by processing circuitry 1470 executing instructions stored on device readable medium 1480 or memory within processing circuitry 1470. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 1470 without executing instructions stored on a separate or discrete device readable medium, such as in a hard-wired manner. In any of those embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry 1470 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 1470 alone or to other components of network node 1460, but are enjoyed by network node 1460 as a whole, and/or by end users and the wireless network generally.

Device readable medium 1480 may comprise any form of volatile or non-volatile computer readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 1470. Device readable medium 1480 may store any suitable instructions, data or information, including a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 1470 and, utilized by network node 1460. Device readable medium 1480 may be used to store any calculations made by processing circuitry 1470 and/or any data received via interface 1490. In some embodiments, processing circuitry 1470 and device readable medium 1480 may be considered to be integrated.

Interface 1490 is used in the wired or wireless communication of signalling and/or data between network node 1460, network 1406, and/or WDs 1410. As illustrated, interface 1490 comprises port(s)/terminal(s) 1494 to send and receive data, for example to and from network 1406 over a wired connection. Interface 1490 also includes radio front end circuitry 1492 that may be coupled to, or in certain embodiments a part of, antenna 1462. Radio front end circuitry 1492 comprises filters 1498 and amplifiers 1496. Radio front end circuitry 1492 may be connected to antenna 1462 and processing circuitry 1470. Radio front end circuitry may be configured to condition signals communicated between antenna 1462 and processing circuitry 1470. Radio front end circuitry 1492 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 1492 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1498 and/or amplifiers 1496. The radio signal may then be transmitted via antenna 1462. Similarly, when receiving data, antenna 1462 may collect radio signals which are then converted into digital data by radio front end circuitry 1492. The digital data may be passed to processing circuitry 1470. In other embodiments, the interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, network node 1460 may not include separate radio front end circuitry 1492, instead, processing circuitry 1470 may comprise radio front end circuitry and may be connected to antenna 1462 without separate radio front end circuitry 1492. Similarly, in some embodiments, all or some of RF transceiver circuitry 1472 may be considered a part of interface 1490. In still other embodiments, interface 1490 may include one or more ports or terminals 1494, radio front end circuitry 1492, and RF transceiver circuitry 1472, as part of a radio unit (not shown), and interface 1490 may communicate with baseband processing circuitry 1474, which is part of a digital unit (not shown).

Antenna 1462 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna 1462 may be coupled to radio front end circuitry 1490 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna 1462 may comprise one or more omni-directional, sector or panel antennas operable to transmit/receive radio signals between, for example, 2 GHz and 66 GHz. An omni-directional antenna may be used to transmit/receive radio signals in any direction, a sector antenna may be used to transmit/receive radio signals from devices within a particular area, and a panel antenna may be a line of sight antenna used to transmit/receive radio signals in a relatively straight line. In some instances, the use of more than one antenna may be referred to as Ml MO. In certain embodiments, antenna 1462 may be separate from network node 1460 and may be connectable to network node 1460 through an interface or port.

Antenna 1462, interface 1490, and/or processing circuitry 1470 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by a network node. Any information, data and/or signals may be received from a wireless device, another network node and/or any other network equipment. Similarly, antenna 1462, interface 1490, and/or processing circuitry 1470 may be configured to perform any transmitting operations described herein as being performed by a network node. Any information, data and/or signals may be transmitted to a wireless device, another network node and/or any other network equipment.

Power circuitry 1487 may comprise, or be coupled to, power management circuitry and is configured to supply the components of network node 1460 with power for performing the functionality described herein. Power circuitry 1487 may receive power from power source 1486. Power source 1486 and/or power circuitry 1487 may be configured to provide power to the various components of network node 1460 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 1486 may either be included in, or external to, power circuitry 1487 and/or network node 1460. For example, network node 1460 may be connectable to an external power source (e.g., an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry 1487. As a further example, power source 1486 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry 1487. The battery may provide backup power should the external power source fail. Other types of power sources, such as photovoltaic devices, may also be used.

Alternative embodiments of network node 1460 may include additional components beyond those shown in Figure 14 that may be responsible for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, network node 1460 may include user interface equipment to allow input of information into network node 1460 and to allow output of information from network node 1460. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1460.

As used herein, wireless device (WD) refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE) a vehicle-mounted wireless terminal device, etc..

A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device. As yet another specific example, in an Internet of Things (loT) scenario, a WD may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another WD and/or a network node. The WD may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the WD may be a UE implementing the 3GPP narrow band internet of things (NB-loT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

As illustrated, wireless device 1410 includes antenna 1411, interface 1414, processing circuitry 1420, device readable medium 1430, user interface equipment 1432, auxiliary equipment 1434, power source 1436 and power circuitry 1437. WD 1410 may include multiple sets of one or more of the illustrated components for different wireless technologies supported by WD 1410, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WMAX, NB-loT, or Bluetooth wireless technologies, just to mention a few. These wireless technologies may be integrated into the same or different chips or set of chips as other components within WD 1410.

Antenna 1411 may include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface 1414. In certain alternative embodiments, antenna 1411 may be separate from WD 1410 and be connectable to WD 1410 through an interface or port. Antenna 1411, interface 1414, and/or processing circuitry 1420 may be configured to perform any receiving or transmitting operations described herein as being performed by a WD. Any information, data and/or signals may be received from a network node and/or another WD. In some embodiments, radio front end circuitry and/or antenna 1411 may be considered an interface.

As illustrated, interface 1414 comprises radio front end circuitry 1412 and antenna 1411. Radio front end circuitry 1412 comprise one or more filters 1418 and amplifiers 1416. Radio front end circuitry 1414 is connected to antenna 1411 and processing circuitry 1420, and is configured to condition signals communicated between antenna 1411 and processing circuitry 1420. Radio front end circuitry 1412 may be coupled to or a part of antenna 1411. In some embodiments, WD 1410 may not include separate radio front end circuitry 1412; rather, processing circuitry 1420 may comprise radio front end circuitry and may be connected to antenna 1411. Similarly, in some embodiments, some or all of RF transceiver circuitry 1422 may be considered a part of interface 1414. Radio front end circuitry 1412 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 1412 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1418 and/or amplifiers 1416. The radio signal may then be transmitted via antenna 1411. Similarly, when receiving data, antenna 1411 may collect radio signals which are then converted into digital data by radio front end circuitry 1412. The digital data may be passed to processing circuitry 1420. In other embodiments, the interface may comprise different components and/or different combinations of components.

Processing circuitry 1420 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software, and/or encoded logic operable to provide, either alone or in conjunction with other WD 1410 components, such as device readable medium 1430, WD 1410 functionality. Such functionality may include providing any of the various wireless features or benefits discussed herein. For example, processing circuitry 1420 may execute instructions stored in device readable medium 1430 or in memory within processing circuitry 1420 to provide the functionality disclosed herein.

As illustrated, processing circuitry 1420 includes one or more of RF transceiver circuitry 1422, baseband processing circuitry 1424, and application processing circuitry 1426. In other embodiments, the processing circuitry may comprise different components and/or different combinations of components. In certain embodiments processing circuitry 1420 of WD 1410 may comprise a SOC. In some embodiments, RF transceiver circuitry 1422, baseband processing circuitry 1424, and application processing circuitry 1426 may be on separate chips or sets of chips. In alternative embodiments, part or all of baseband processing circuitry 1424 and application processing circuitry 1426 may be combined into one chip or set of chips, and RF transceiver circuitry 1422 may be on a separate chip or set of chips. In still alternative embodiments, part or all of RF transceiver circuitry 1422 and baseband processing circuitry 1424 may be on the same chip or set of chips, and application processing circuitry 1426 may be on a separate chip or set of chips. In yet other alternative embodiments, part or all of RF transceiver circuitry 1422, baseband processing circuitry 1424, and application processing circuitry 1426 may be combined in the same chip or set of chips. In some embodiments, RF transceiver circuitry 1422 may be a part of interface 1414. RF transceiver circuitry 1422 may condition RF signals for processing circuitry 1420.

In certain embodiments, some or all of the functionality described herein as being performed by a WD may be provided by processing circuitry 1420 executing instructions stored on device readable medium 1430, which in certain embodiments may be a computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 1420 without executing instructions stored on a separate or discrete device readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry 1420 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 1420 alone or to other components of WD 1410, but are enjoyed by WD 1410 as a whole, and/or by end users and the wireless network generally.

Processing circuitry 1420 may be configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being performed by a WD. These operations, as performed by processing circuitry 1420, may include processing information obtained by processing circuitry 1420 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD 1410, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Device readable medium 1430 may be operable to store a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 1420. Device readable medium 1430 may include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a Compact

Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 1420. In some embodiments, processing circuitry 1420 and device readable medium 1430 may be considered to be integrated.

User interface equipment 1432 may provide components that allow for a human user to interact with WD 1410. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment 1432 may be operable to produce output to the user and to allow the user to provide input to WD 1410. The type of interaction may vary depending on the type of user interface equipment 1432 installed in WD 1410. For example, if WD 1410 is a smart phone, the interaction may be via a touch screen; if WD 1410 is a smart meter, the interaction may be through a screen that provides usage (e.g., the number of gallons used) or a speaker that provides an audible alert (e.g., if smoke is detected). User interface equipment 1432 may include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment 1432 is configured to allow input of information into WD 1410, and is connected to processing circuitry 1420 to allow processing circuitry 1420 to process the input information. User interface equipment 1432 may include, for example, a microphone, a proximity or other sensor, keys/buttons, a touch display, one or more cameras, a USB port, or other input circuitry. User interface equipment 1432 is also configured to allow output of information from WD 1410, and to allow processing circuitry 1420 to output information from WD 1410. User interface equipment 1432 may include, for example, a speaker, a display, vibrating circuitry, a USB port, a headphone interface, or other output circuitry. Using one or more input and output interfaces, devices, and circuits, of user interface equipment 1432, WD 1410 may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein.

Auxiliary equipment 1434 is operable to provide more specific functionality which may not be generally performed by WDs. This may comprise specialized sensors for doing measurements for various purposes, interfaces for additional types of communication such as wired communications etc. The inclusion and type of components of auxiliary equipment 1434 may vary depending on the embodiment and/or scenario.

Power source 1436 may, in some embodiments, be in the form of a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic devices or power cells, may also be used. WD 1410 may further comprise power circuitry 1437 for delivering power from power source 1436 to the various parts of WD 1410 which need power from power source 1436 to carry out any functionality described or indicated herein. Power circuitry 1437 may in certain embodiments comprise power management circuitry. Power circuitry 1437 may additionally or alternatively be operable to receive power from an external power source; in which case WD 1410 may be connectable to the external power source (such as an electricity outlet) via input circuitry or an interface such as an electrical power cable. Power circuitry 1437 may also in certain embodiments be operable to deliver power from an external power source to power source 1436. This may be, for example, for the charging of power source 1436. Power circuitry 1437 may perform any formatting, converting, or other modification to the power from power source 1436 to make the power suitable for the respective components of WD 1410 to which power is supplied.

Figure 15 illustrates one embodiment of a UE in accordance with various aspects described herein. As used herein, a user equipment or UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter). UE 15200 may be any UE identified by the 3^rd Generation Partnership Project (3GPP), including a NB-loT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. UE 1500, as illustrated in Figure 15, is one example of a WD configured for communication in accordance with one or more communication standards promulgated by the 3^rd Generation Partnership Project (3GPP), such as 3GPP’s GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, the term WD and UE may be used interchangeable. Accordingly, although Figure 15 is a UE, the components discussed herein are equally applicable to a WD, and vice-versa.

In Figure 15, UE 1500 includes processing circuitry 1501 that is operatively coupled to input/output interface 1505, radio frequency (RF) interface 1509, network connection interface 1511, memory 1515 including random access memory (RAM) 1517, read-only memory (ROM) 1519, and storage medium 1521 or the like, communication subsystem 1531, power source 1533, and/or any other component, or any combination thereof. Storage medium 1521 includes operating system 1523, application program 1525, and data 1527. In other embodiments, storage medium 1521 may include other similar types of information. Certain UEs may utilize all of the components shown in Figure 15, or only a subset of the components. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

In Figure 15, processing circuitry 1501 may be configured to process computer instructions and data. Processing circuitry 1501 may be configured to implement any sequential state machine operative to execute machine instructions stored as machine-readable computer programs in the memory, such as one or more hardware-implemented state machines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logic together with appropriate firmware; one or more stored program, general-purpose processors, such as a microprocessor or Digital

Signal Processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 1501 may include two central processing units (CPUs). Data may be information in a form suitable for use by a computer.

In the depicted embodiment, input/output interface 1505 may be configured to provide a communication interface to an input device, output device, or input and output device. UE 1500 may be configured to use an output device via input/output interface 1505. An output device may use the same type of interface port as an input device. For example, a USB port may be used to provide input to and output from UE 1500. The output device may be a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. UE 1500 may be configured to use an input device via input/output interface 1505 to allow a user to capture information into UE 1500. The input device may include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence- sensitive display may include a capacitive or resistive touch sensor to sense input from a user.

A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, another like sensor, or any combination thereof. For example, the input device may be an accelerometer, a magnetometer, a digital camera, a microphone, and an optical sensor.

In Figure 15, RF interface 1509 may be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna. Network connection interface 1511 may be configured to provide a communication interface to network 1543a. Network 1543a may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1543a may comprise a Wi-Fi network. Network connection interface 1511 may be configured to include a receiver and a transmitter interface used to communicate with one or more other devices over a communication network according to one or more communication protocols, such as Ethernet, TCP/IP, SONET, ATM, or the like. Network connection interface 1511 may implement receiver and transmitter functionality appropriate to the communication network links (e.g., optical, electrical, and the like). The transmitter and receiver functions may share circuit components, software or firmware, or alternatively may be implemented separately.

RAM 1517 may be configured to interface via bus 1502 to processing circuitry 1501 to provide storage or caching of data or computer instructions during the execution of software programs such as the operating system, application programs, and device drivers. ROM 1519 may be configured to provide computer instructions or data to processing circuitry 1501. For example, ROM 1519 may be configured to store invariant low-level system code or data for basic system functions such as basic input and output (I/O), startup, or reception of keystrokes from a keyboard that are stored in a non-volatile memory. Storage medium 1521 may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives. In one example, storage medium 1521 may be configured to include operating system 1523, application program 1525 such as a web browser application, a widget or gadget engine or another application, and data file 1527. Storage medium 1521 may store, for use by UE 1500, any of a variety of various operating systems or combinations of operating systems.

Storage medium 1521 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), floppy disk drive, flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as a subscriber identity module or a removable user identity (SIM/RUIM) module, other memory, or any combination thereof. Storage medium 1521 may allow UE 1500 to access computer-executable instructions, application programs or the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied in storage medium 1521, which may comprise a device readable medium.

In Figure 15, processing circuitry 1501 may be configured to communicate with network 1543b using communication subsystem 1531. Network 1543a and network 1543b may be the same network or networks or different network or networks. Communication subsystem 1531 may be configured to include one or more transceivers used to communicate with network 1543b. For example, communication subsystem 1531 may be configured to include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication such as another WD, UE, or base station of a radio access network (RAN) according to one or more communication protocols, such as IEEE 802.11, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver may include transmitter 1533 and/or receiver 1535 to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter 1533 and receiver 1535 of each transceiver may share circuit components, software or firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions of communication subsystem 1531 may include data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. For example, communication subsystem 1531 may include cellular communication, Wi-Fi communication, Bluetooth communication, and GPS communication. Network 1543b may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1543b may be a cellular network, a W-Fi network, and/or a near-field network. Power source 1513 may be configured to provide alternating current (AC) or direct current (DC) power to components of UE 1500.

The features, benefits and/or functions described herein may be implemented in one of the components of UE 1500 or partitioned across multiple components of UE 1500. Further, the features, benefits, and/or functions described herein may be implemented in any combination of hardware, software or firmware. In one example, communication subsystem 1531 may be configured to include any of the components described herein. Further, processing circuitry 1501 may be configured to communicate with any of such components over bus 1502. In another example, any of such components may be represented by program instructions stored in memory that when executed by processing circuitry 1501 perform the corresponding functions described herein. In another example, the functionality of any of such components may be partitioned between processing circuitry 1501 and communication subsystem 1531. In another example, the non-computationally intensive functions of any of such components may be implemented in software or firmware and the computationally intensive functions may be implemented in hardware.

Figure 16 is a schematic block diagram illustrating a virtualization environment 1600 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to a node (e.g., a virtualized base station or a virtualized radio access node) or to a device (e.g., a UE, a wireless device or any other type of communication device) or components thereof and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components (e.g., via one or more applications, components, functions, virtual machines or containers executing on one or more physical processing nodes in one or more networks).

In some embodiments, some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines implemented in one or more virtual environments 1600 hosted by one or more of hardware nodes 1630.

Further, in embodiments in which the virtual node is not a radio access node or does not require radio connectivity (e.g., a core network node), then the network node may be entirely virtualized.

The functions may be implemented by one or more applications 1620 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) operative to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein. Applications 1620 are run in virtualization environment 1600 which provides hardware 1630 comprising processing circuitry 1660 and memory 1690. Memory 1690 contains instructions 1695 executable by processing circuitry 1660 whereby application 1620 is operative to provide one or more of the features, benefits, and/or functions disclosed herein.

Virtualization environment 1600, comprises general-purpose or special-purpose network hardware devices 1630 comprising a set of one or more processors or processing circuitry 1660, which may be commercial off-the-shelf (COTS) processors, dedicated Application Specific Integrated Circuits (ASICs), or any other type of processing circuitry including digital or analog hardware components or special purpose processors. Each hardware device may comprise memory 1690-1 which may be non-persistent memory for temporarily storing instructions 1695 or software executed by processing circuitry 1660. Each hardware device may comprise one or more network interface controllers (NICs) 1670, also known as network interface cards, which include physical network interface 1680. Each hardware device may also include non-transitory, persistent, machine-readable storage media 1690-2 having stored therein software 1695 and/or instructions executable by processing circuitry 1660. Software 1695 may include any type of software including software for instantiating one or more virtualization layers 1650 (also referred to as hypervisors), software to execute virtual machines 1640 as well as software allowing it to execute functions, features and/or benefits described in relation with some embodiments described herein.

Virtual machines 1640, comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1650 or hypervisor. Different embodiments of the instance of virtual appliance 1620 may be implemented on one or more of virtual machines 1640, and the implementations may be made in different ways.

During operation, processing circuitry 1660 executes software 1695 to instantiate the hypervisor or virtualization layer 1650, which may sometimes be referred to as a virtual machine monitor (VMM). Virtualization layer 1650 may present a virtual operating platform that appears like networking hardware to virtual machine 1640.

As shown in Figure 16, hardware 1630 may be a standalone network node with generic or specific components. Hardware 1630 may comprise antenna 16225 and may implement some functions via virtualization. Alternatively, hardware 1630 may be part of a larger cluster of hardware (e.g. such as in a data center or customer premise equipment (CPE)) where many hardware nodes work together and are managed via management and orchestration (MANO) 16100, which, among others, oversees lifecycle management of applications 1620.

Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

In the context of NFV, virtual machine 1640 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of virtual machines 1640, and that part of hardware 1630 that executes that virtual machine, be it hardware dedicated to that virtual machine and/or hardware shared by that virtual machine with others of the virtual machines 1640, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) is responsible for handling specific network functions that run in one or more virtual machines 1640 on top of hardware networking infrastructure 1630 and corresponds to application 1620 in Figure 16.

In some embodiments, one or more radio units 16200 that each include one or more transmitters 16220 and one or more receivers 16210 may be coupled to one or more antennas 16225. Radio units 16200 may communicate directly with hardware nodes 1630 via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station.

In some embodiments, some signalling can be effected with the use of control system 16230 which may alternatively be used for communication between the hardware nodes 1630 and radio units 16200.

Figure 17 illustrates a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments. In particular, with reference to FIGURE 17, in accordance with an embodiment, a communication system includes telecommunication network 1710, such as a 3GPP-type cellular network, which comprises access network 1711, such as a radio access network, and core network 1714. Access network 1711 comprises a plurality of base stations 1712a, 1712b, 1712c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1713a, 1713b, 1713c. Each base station 1712a, 1712b, 1712c is connectable to core network 1714 over a wired or wireless connection 1715. A first UE 1791 located in coverage area 1713c is configured to wirelessly connect to, or be paged by, the corresponding base station 1712c. A second UE 1792 in coverage area 1713a is wirelessly connectable to the corresponding base station 1712a. While a plurality of UEs 1791, 1792 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 1712.

Telecommunication network 1710 is itself connected to host computer 1730, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer 1730 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 1721 and 1722 between telecommunication network 1710 and host computer 1730 may extend directly from core network 1714 to host computer 1730 or may go via an optional intermediate network 1720. Intermediate network 1720 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 1720, if any, may be a backbone network or the Internet; in particular, intermediate network 1720 may comprise two or more sub-networks (not shown).

The communication system of Figure 17 as a whole enables connectivity between the connected UEs 1791, 1792 and host computer 1730. The connectivity may be described as an over-the-top (OTT) connection 1750. Host computer 1730 and the connected UEs 1791, 1792 are configured to communicate data and/or signaling via OTT connection 1750, using access network 1711, core network 1714, any intermediate network 1720 and possible further infrastructure (not shown) as intermediaries. OTT connection 1750 may be transparent in the sense that the participating communication devices through which OTT connection 1750 passes are unaware of routing of uplink and downlink communications. For example, base station 1712 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 1730 to be forwarded (e.g., handed over) to a connected UE 1791. Similarly, base station 1712 need not be aware of the future routing of an outgoing uplink communication originating from the UE 1791 towards the host computer 1730.

Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Figure 18. Figure 18 illustrates host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments In communication system 1800, host computer 1810 comprises hardware 1815 including communication interface 1816 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 1800. Host computer 1810 further comprises processing circuitry 1818, which may have storage and/or processing capabilities. In particular, processing circuitry 1818 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer 1810 further comprises software 1811, which is stored in or accessible by host computer 1810 and executable by processing circuitry 1818. Software 1811 includes host application 1812. Host application 1812 may be operable to provide a service to a remote user, such as UE 1830 connecting via OTT connection 1850 terminating at UE 1830 and host computer 1810. In providing the service to the remote user, host application 1812 may provide user data which is transmitted using OTT connection 1850.

Communication system 1800 further includes base station 1820 provided in a telecommunication system and comprising hardware 1825 enabling it to communicate with host computer 1810 and with UE 1830. Hardware 1825 may include communication interface 1826 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 1800, as well as radio interface 1827 for setting up and maintaining at least wireless connection 1870 with UE 1830 located in a coverage area (not shown in Figure 18) served by base station 1820. Communication interface 1826 may be configured to facilitate connection 1860 to host computer 1810. Connection 1860 may be direct or it may pass through a core network (not shown in Figure 18) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware 1825 of base station 1820 further includes processing circuitry 1828, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station 1820 further has software 1821 stored internally or accessible via an external connection.

Communication system 1800 further includes UE 1830 already referred to. Its hardware 1835 may include radio interface 1837 configured to set up and maintain wireless connection 1870 with a base station serving a coverage area in which UE 1830 is currently located. Hardware 1835 of UE 1830 further includes processing circuitry 1838, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE 1830 further comprises software 1831, which is stored in or accessible by UE 1830 and executable by processing circuitry 1838. Software 1831 includes client application 1832. Client application 1832 may be operable to provide a service to a human or non-human user via UE 1830, with the support of host computer 1810. In host computer 1810, an executing host application 1812 may communicate with the executing client application 1832 via OTT connection 1850 terminating at UE 1830 and host computer 1810. In providing the service to the user, client application 1832 may receive request data from host application 1812 and provide user data in response to the request data. OTT connection 1850 may transfer both the request data and the user data. Client application 1832 may interact with the user to generate the user data that it provides.

It is noted that host computer 1810, base station 1820 and UE 1830 illustrated in Figure 18 may be similar or identical to host computer 1730, one of base stations 1712a, 1712b, 1712c and one of UEs 1791, 1792 of Figure 17, respectively. This is to say, the inner workings of these entities may be as shown in Figure 18 and independently, the surrounding network topology may be that of Figure 17.

In Figure 18, OTT connection 1850 has been drawn abstractly to illustrate the communication between host computer 1810 and UE 1830 via base station 1820, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE 1830 or from the service provider operating host computer 1810, or both. While OTT connection 1850 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

Wireless connection 1870 between UE 1830 and base station 1820 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE 1830 using OTT connection 1850, in which wireless connection 1870 forms the last segment.

A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection 1850 between host computer 1810 and UE 1830, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection 1850 may be implemented in software 1811 and hardware 1815 of host computer 1810 or in software 1831 and hardware 1835 of UE 1830, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection 1850 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 1811, 1831 may compute or estimate the monitored quantities. The reconfiguring of OTT connection 1850 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station 1820, and it may be unknown or imperceptible to base station 1820. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer 1810’s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software 1811 and 1831 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection 1850 while it monitors propagation times, errors etc.

Figure 19 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 17 and 18. For simplicity of the present disclosure, only drawing references to Figure 19 will be included in this section. In step 1910, the host computer provides user data. In substep 1911 (which may be optional) of step 1910, the host computer provides the user data by executing a host application. In step 1920, the host computer initiates a transmission carrying the user data to the UE. In step 1930 (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1940 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

Figure 20 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 17 and 18. For simplicity of the present disclosure, only drawing references to Figure 20 will be included in this section. In step 2010 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step 2020, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step 2030 (which may be optional), the UE receives the user data carried in the transmission.

Figure 21 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 17 and 18. For simplicity of the present disclosure, only drawing references to Figure 21 will be included in this section. In step 2110 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 2120, the UE provides user data. In substep 2121 (which may be optional) of step 2120, the UE provides the user data by executing a client application. In substep 2111 (which may be optional) of step 2110, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep 2130 (which may be optional), transmission of the user data to the host computer. In step 2140 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

Figure 22 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 17 and 18. For simplicity of the present disclosure, only drawing references to Figure 22 will be included in this section. In step 2210 (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step 2220 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 2230 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station. Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

In view of the above, then, embodiments herein generally include a communication system including a host computer. The host computer may comprise processing circuitry configured to provide user data. The host computer may also comprise a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE). The cellular network may comprise a base station having a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the embodiments described above for a base station.

In some embodiments, the communication system further includes the base station.

In some embodiments, the communication system further includes the UE, wherein the UE is configured to communicate with the base station.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data. In this case, the UE comprises processing circuitry configured to execute a client application associated with the host application.

Embodiments herein also include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, providing user data. The method may also comprise, at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station. The base station performs any of the steps of any of the embodiments described above for a base station.

In some embodiments, the method further comprising, at the base station, transmitting the user data.

In some embodiments, the user data is provided at the host computer by executing a host application. In this case, the method further comprises, at the UE, executing a client application associated with the host application.

Embodiments herein also include a user equipment (UE) configured to communicate with a base station. The UE comprises a radio interface and processing circuitry configured to perform any of the embodiments above described for a UE.

Embodiments herein further include a communication system including a host computer. The host computer comprises processing circuitry configured to provide user data, and a communication interface configured to forward user data to a cellular network for transmission to a user equipment (UE). The UE comprises a radio interface and processing circuitry. The UE’s components are configured to perform any of the steps of any of the embodiments described above for a UE.

In some embodiments, the cellular network further includes a base station configured to communicate with the UE.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data. The UE’s processing circuitry is configured to execute a client application associated with the host application.

Embodiments also include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, providing user data and initiating a transmission carrying the user data to the UE via a cellular network comprising the base station. The UE performs any of the steps of any of the embodiments described above for a UE.

In some embodiments, the method further comprises, at the UE, receiving the user data from the base station.

Embodiments herein further include a communication system including a host computer. The host computer comprises a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station. The UE comprises a radio interface and processing circuitry. The UE’s processing circuitry is configured to perform any of the steps of any of the embodiments described above for a UE.

In some embodiments the communication system further includes the UE.

In some embodiments, the communication system further including the base station. In this case, the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE to the base station.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application. And the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application, thereby providing request data. And the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.

Embodiments herein also include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, receiving user data transmitted to the base station from the UE. The UE performs any of the steps of any of the embodiments described above for the UE.

In some embodiments, the method further comprises, at the UE, providing the user data to the base station.

In some embodiments, the method also comprises, at the UE, executing a client application, thereby providing the user data to be transmitted. The method may further comprise, at the host computer, executing a host application associated with the client application.

In some embodiments, the method further comprises, at the UE, executing a client application, and, at the UE, receiving input data to the client application. The input data is provided at the host computer by executing a host application associated with the client application. The user data to be transmitted is provided by the client application in response to the input data.

Embodiments also include a communication system including a host computer. The host computer comprises a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station. The base station comprises a radio interface and processing circuitry. The base station’s processing circuitry is configured to perform any of the steps of any of the embodiments described above for a base station.

In some embodiments, the communication system further includes the UE. The UE is configured to communicate with the base station.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application. And the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.

Embodiments moreover include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE. The UE performs any of the steps of any of the embodiments described above for a UE.

In some embodiments, the method further comprises, at the base station, receiving the user data from the UE.

In some embodiments, the method further comprises, at the base station, initiating a transmission of the received user data to the host computer.

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the description.

The term unit may have conventional meaning in the field of electronics, electrical devices and/or electronic devices and may include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

Some of the embodiments contemplated herein are described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

Notably, modifications and other embodiments of the disclosed invention(s) will come to mind to one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention(s) is/are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of this disclosure. Although specific terms may be employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

CLAIMS What is claimed is:

1. A method performed by a first network node (14) configured to operate as a master network node for multi-connectivity operation of a wireless device (12), the method comprising: receiving (300) a message (26) that indicates that a wireless device (12) operating in multi-connectivity has executed a conditional handover; and based on receiving the message (26), transmitting (310) a secondary node release request message (24) to a second network node (16) operating as a secondary network node for multi-connectivity operation of the wireless device (12), wherein the secondary node release request message (24) requests release of resources for the wireless device (12) at the second network node (16).

2. The method of claim 1 , wherein the received message (26) is a handover success message that indicates the wireless device (12) has successfully accessed a candidate target node for the conditional handover.

3. The method of any of claims 1-2, wherein the message (26) is received from the wireless device (12) or from a candidate target node (18-1... 18-N) for the conditional handover.

4. The method of any of claims 1-3, further comprising: transmitting (200), from the first network node (14) to a candidate target node, a handover request message that requests preparation of resources at the candidate target node for the conditional handover; after transmitting the handover request, receiving (210) from the candidate target node a handover request acknowledge message that informs the first network node (14) about prepared resources at the candidate target node for the conditional handover; and refraining (220) from transmitting the secondary node release request message (24) to the second network node (16) in response to receiving the handover request acknowledge message, and instead waiting to transmit the secondary node release request message (24) to the second network node (16) until the first network node (14) receives the message that indicates the wireless device (12) has executed the conditional handover.

5. The method of any of claims 1-4, wherein the master network node is a source master network node for the conditional handover and wherein the second network node is a source secondary network node for the conditional handover.

6. The method of any of claims 1-5, wherein the secondary node release request message (24) indicates a cause of the secondary node release request message (24) as being conditional master cell group, MCG, mobility or conditional master node mobility.

7. The method of any of claims 1-6, further comprising, after receiving the message that indicates the wireless device (12) has executed the conditional handover, initiating an address indication procedure with the second network node (16) in order to provide a data forwarding address to the second network node (16), wherein the data forwarding address is an address to which the second network node (16) is to forward data for the wireless device (12).

8. The method of claim 7, further comprising: transmitting, from the first network node (14) to a candidate target node, a handover request message that requests preparation of resources at the candidate target node for the conditional handover; after transmitting the handover request, receiving from the candidate target node a handover request acknowledge message that informs the first network node (14) about prepared resources at the candidate target node for the conditional handover; and refraining from initiating the address indication procedure with the second network node (16) in response to receiving the handover request acknowledge message, and instead waiting to initiate the address indication procedure with the second network node (16) until the first network node (14) receives the message that indicates the wireless device (12) has executed the conditional handover.

9. The method of any of claims 1-8, further comprising, after or in conjunction with transmitting the secondary node release request message (24), receiving (330) data from the second network node (16) and forwarding the data to a target node towards which the wireless device (12) has executed conditional handover.

10. A first network node (14) configured to operate as a master network node for multi connectivity operation of a wireless device (12), the first network node (14) configured to: receive a message that indicates that a wireless device (12) operating in multi connectivity has executed a conditional handover; and based on receiving the message, transmit a secondary node release request message (24) to a second network node (16) operating as a secondary network node for multi-connectivity operation of the wireless device (12), wherein the secondary node release request message (24) requests release of resources for the wireless device (12) at the second network node (16).

11. The first network node (14) of claim 10, configured to perform the method of any of claims 2-9.

12. A computer program comprising instructions which, when executed by at least one processor of a first network node (14), causes the first network node (14) to perform the method of any of claims 1-9.

13. A carrier containing the computer program of claim 12, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

14. A first network node (14) configured to operate as a master network node for multi connectivity operation of a wireless device (12), the first network node (14) comprising: communication circuitry (420); and processing circuitry (410) configured to: receive a message that indicates that a wireless device (12) operating in multi connectivity has executed a conditional handover; and based on receiving the message, transmit a secondary node release request message (24) to a second network node (16) operating as a secondary network node for multi-connectivity operation of the wireless device (12), wherein the secondary node release request message (24) requests release of resources for the wireless device (12) at the second network node (16).

15. The first network node (14) of claim 14, the processing circuitry (410) configured to perform the method of any of claims 2-10.