WO2019200507A1

WO2019200507A1 - Control of d2d duplication

Info

Publication number: WO2019200507A1
Application number: PCT/CN2018/083195
Authority: WO
Inventors: Ling Yu; Vinh Van Phan; Dawid Koziol; Haitao Li; Jedrzej STANCZAK
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2018-04-16
Filing date: 2018-04-16
Publication date: 2019-10-24
Also published as: CN112237048A; CN112237048B

Abstract

An apparatus comprising means for: receiving a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group; causing a device to device communication transmission of a data packet that is part of the logical channel group in a first at least one resource; and in response to the indication, causing a device to device communication transmission of a duplicate of the data packet that is part of the logical channel group in a second at least one resource.

Description

CONTROL OF D2D DUPLICATION

Field

The present application relates to a method, apparatus, system and computer program. In particular, but not exclusively, the present application relates to indicating in a device to device communication’s grant message that duplicate transmission is enabled for a logical channel group.

Background

A communication system can be seen as a facility that enables communication sessions between two or more entities such as user terminals, base stations and/or other nodes by providing carriers between the various entities involved in the communications path. A communication system can be provided, for example, by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, video, electronic mail (email) , text message, multimedia and/or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

In a wireless communication system, at least a part of a communication session between at least two stations occurs over a wireless link. Examples of wireless systems comprise public land mobile networks (PLMN) , satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN) . The wireless systems can typically be divided into cells, and are therefore often referred to as cellular systems.

A user can access the communication system by means of an appropriate communication device or terminal. A communication device of a user may be referred to as user equipment (UE) or user device. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other users. The communication device may access a carrier provided by a station, for example a base station of a cell, and transmit and/or receive communications on the carrier.

The communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and/or parameters which shall be used for the connection are also typically defined. One example of a communications system is UTRAN (3G radio) . Other examples of communication systems are the long-term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology and so-called 5G or New Radio (NR) networks. Standardization of 5G or New Radio networks is currently under discussion. LTE is being standardized by the 3rd Generation Partnership Project (3GPP) .

Summary

According to a first aspect, there is provided apparatus comprising means for: receiving a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group; causing a device to device communication transmission of a data packet that is part of the logical channel group in a first at least one resource; and in response to the indication, causing a device to device communication transmission of a duplicate of the data packet that is part of the logical channel group in a second at least one resource.

In some embodiments, the grant message comprises an instruction to autonomously select resources, the apparatus comprising means for in response to the instruction, autonomously selecting the second at least one resource.

In some embodiments, the grant message comprises an indication of a carrier, the apparatus comprising means for, in response to the indication, autonomously selecting the second at least one resource from the carrier.

In some embodiments, the device to device communication grant message provides a grant for a carrier comprising the first at least one resource.

In some embodiments, the device to device communication grant message comprises an indication of the second at least one resource, and the apparatus comprises means for, in response to the indication of the second at least one resource, causing the device to device communication transmission of the duplicate of the data packet in the second at least one resource.

In some embodiments, the device to device communication grant message provides a grant for a carrier comprising the second at least one resource.

In some embodiments, the first at least one resource and the second at least one resource belong to different carriers.

According to a second aspect, there is provided an apparatus comprising means for transmitting to a communication device, a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group.

In some embodiments, the grant message comprises an instruction to autonomously select resources.

In some embodiments, the indication comprises an indication of a carrier on which the duplicate transmission is to be made.

In some embodiments, the device to device communication grant message comprises a grant for a carrier in which an original transmission corresponding to the duplicate transmission is to be made by the communication device.

In some embodiments, the indication comprises an indication of a second at least one resource on which the duplicate transmission is to be made.

In some embodiments, the device to device communication grant message provides a grant for a carrier in which the duplicate transmission is to be made.

In some embodiments, the apparatus comprises means for: receiving from a plurality of communication devices, a plurality of buffer status reports; and determining from the plurality of buffer status reports, to enable the duplicate transmission for the logical channel group.

In some embodiments, the apparatus comprises means for determining to enable the duplicate transmission for the logical channel group in dependence upon a load of one or more carriers associated with the logical channel group.

In some embodiments, the grant message comprises an identifier of the logical channel group.

According to a third aspect, there is provided a method comprising: receiving a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group; causing a device to device communication transmission of a data packet that is part of the logical channel group in a first at least one resource; and in response to the indication, causing a device to device communication transmission of a duplicate of the data packet that is part of the logical channel group in a second at least one resource.

In some embodiments, the grant message comprises an instruction to autonomously select resources, the method comprising in response to the instruction, autonomously selecting the second at least one resource.

In some embodiments, the grant message comprises an indication of a carrier, the method comprising, in response to the indication, autonomously selecting the second at least one resource from the carrier.

In some embodiments, the device to device communication grant message comprises an indication of the second at least one resource, and the method comprises, in response to the indication of the second at least one resource, causing the device to device communication transmission of the duplicate of the data packet in the second at least one resource.

According to a fourth aspect, there is provided a method comprising transmitting to a communication device, a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group.

In some embodiments, the method comprises: receiving from a plurality of communication devices, a plurality of buffer status reports; and determining from the plurality of buffer status reports, to enable the duplicate transmission for the logical channel group.

In some embodiments, the method comprises determining to enable the duplicate transmission for the logical channel group in dependence upon a load of one or more carriers associated with the logical channel group.

According to a fifth aspect, there is provided a computer program product for a computer, comprising software code portions for performing a method when said product is run on the computer, the method comprising: receiving a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group; causing a device to device communication transmission of a data packet that is part of the logical channel group in a first at least one resource; and in response to the indication, causing a device to device communication transmission of a duplicate of the data packet that is part of the logical channel group in a second at least one resource.

According to a sixth aspect, there is provided a computer program product for a computer, comprising software code portions for performing a method when said product is run on the computer, the method comprising: transmitting to a communication device, a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group.

According to a seventh aspect, there is provided an apparatus comprising: at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: receive a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group; cause a device to device communication transmission of a data packet that is part of the logical channel group in a first at least one resource; and in response to the indication, cause a device to device communication transmission of a duplicate of the data packet that is part of the logical channel group in a second at least one resource.

According to an eighth aspect, there is provided an apparatus comprising: at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: transmit to a communication device, a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group.

In the above, many different examples have been described. It should be appreciated that further examples may be provided by the combination of any two or more of the examples described above.

Description of Figures

Some examples will now be described with reference to the accompanying Figures in which:

Figure 1 shows a schematic diagram of an example communication system comprising a base station and a plurality of communication devices;

Figure 2 shows a schematic diagram of an example mobile communication device;

Figure 3 shows a schematic diagram of an example control apparatus;

Figure 4 illustrates a communication system according to examples of the application;

Figure 5 illustrates a message signalling diagram;

Figure 6 illustrates a method that may be performed in a communication device;

Figure 7 illustrates a method that may be performed in a base station or in a control apparatus for a base station; and

Figure 8 illustrates an example of a non-transitory computer readable medium.

Detailed description

Before explaining in detail the examples, certain general principles of a wireless communication system and mobile communication devices are briefly explained with reference to Figures 1 to 2 to assist in understanding the technology underlying the described examples.

In a wireless communication system 100, such as that shown in Figure 1, mobile communication devices or user equipment (UE) 102, 104, 105 are provided wireless access via at least one base station or similar wireless transmitting and/or receiving node or point. Base stations are typically controlled by at least one appropriate controller apparatus, so as to enable operation thereof and management of mobile communication devices in communication with the base stations. The controller apparatus may be located in a radio access network (e.g. wireless communication system 100) or in a core network (CN) (not shown) and may be implemented as one central apparatus or its functionality may be distributed over several apparatus. The controller apparatus may be part of the base station and/or provided by a separate entity such as a Radio Network Controller. In Figure 1

control apparatus

108 and 109 are shown to control the respective macro

level base stations

106 and 107. The control apparatus of a base station can be interconnected with other control entities. The control apparatus is typically provided with memory capacity and at least one data processor. The control apparatus and functions may be distributed between a plurality of control units. In some systems, the control apparatus may additionally or alternatively be provided in a radio network controller.

In Figure 1,

base stations

106 and 107 are shown as connected to a wider communications network 113 via gateway 112. A further gateway function may be provided to connect to another network.

The

smaller base stations

116, 118 and 120 may also be connected to the network 113, for example by a separate gateway function and/or via the controllers of the macro level stations. The

base stations

116, 118 and 120 may be pico or femto level base stations or the like. In the example,

stations

116 and 118 are connected via a gateway 111 whilst station 120 connects via the controller apparatus 108. In some embodiments, the smaller stations may not be provided.

Smaller base stations

116, 118 and 120 may be part of a second network, for example WLAN and may be WLAN APs.

An example of wireless communication systems are architectures standardized by the 3rd Generation Partnership Project (3GPP) . A 3GPP based development is often referred to as the long term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology. The various development stages of the 3GPP specifications are referred to as releases. More recent developments of the LTE are often referred to as LTE Advanced (LTE-A) . The LTE employs a mobile architecture known as the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) . Base stations of such systems are known as evolved or enhanced Node Bs (eNBs) and provide E-UTRAN features such as user plane Packet Data Convergence/Radio Link Control/Medium Access Control/Physical layer protocol (PDCP/RLC/MAC/PHY) and control plane Radio Resource Control (RRC) protocol terminations towards the communication devices. Other examples of radio access system comprise those provided by base stations of systems that are based on technologies such as wireless local area network (WLAN) and/or WiMax (Worldwide Interoperability for Microwave Access) . A base station can provide coverage for an entire cell or similar radio service area.

An example of a suitable communications system is the 5G or NR concept. Network architecture in NR may be similar to that of LTE-advanced. Base stations of NR systems may be known as next generation Node Bs (gNBs) . Changes to the network architecture may depend on the need to support various radio technologies and finer QoS support, and some on-demand requirements for e.g. QoS levels to support QoE of user point of view. Also network aware services and applications, and service and application aware networks may bring changes to the architecture. Those are related to Information Centric Network (ICN) and User-Centric Content Delivery Network (UC-CDN) approaches. NR may use multiple input -multiple output (MIMO) antennas, many more base stations or nodes than the LTE (a so-called small cell concept) , including macro sites operating in co-operation with smaller stations and perhaps also employing a variety of radio technologies for better coverage and enhanced data rates.

Future networks may utilise network functions virtualization (NFV) which is a network architecture concept that proposes virtualizing network node functions into “building blocks” or entities that may be operationally connected or linked together to provide services. A virtualized network function (VNF) may comprise one or more virtual machines running computer program codes using standard or general type servers instead of customized hardware. Cloud computing or data storage may also be utilized. In radio communications this may mean node operations to be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. It should also be understood that the distribution of labour between core network operations and base station operations may differ from that of the LTE or even be non-existent.

A possible mobile communication device will now be described in more detail with reference to Figure 2 showing a schematic, partially sectioned view of a communication device 200. Such a communication device is often referred to as a user equipment (UE) or terminal. An appropriate mobile communication device may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’ , a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle) , personal data assistant (PDA) or a tablet provided with wireless communication capabilities, or any combinations of these or the like. A mobile communication device may provide, for example, communication of data for carrying communications such as voice, electronic mail (email) , text message, multimedia and so on. Users may thus be offered and provided numerous services via their communication devices. Non-limiting examples of these services comprise two-way or multi-way calls, data communication or multimedia services or simply an access to a data communications network system, such as the Internet. Users may also be provided broadcast or multicast data. Non-limiting examples of the content comprise downloads, television and radio programs, videos, advertisements, various alerts and other information.

The

communication devices

102, 104, 105 may access the communication system based on various access techniques, such as code division multiple access (CDMA) , or wideband CDMA (WCDMA) . Other non-limiting examples comprise time division multiple access (TDMA) , frequency division multiple access (FDMA) and various schemes thereof such as the interleaved frequency division multiple access (IFDMA) , single carrier frequency division multiple access (SC-FDMA) and orthogonal frequency division multiple access (OFDMA) , space division multiple access (SDMA) and so on.

The mobile device 200 may receive signals over an air or radio interface 207 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 2, transceiver apparatus is designated schematically by block 206. The transceiver apparatus 206 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

A mobile device is typically provided with at least one data processing entity 201, at least one memory 202 and other possible components 203 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 204. The user may control the operation of the mobile device by means of a suitable user interface such as key pad 205, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 208, a speaker and a microphone can be also provided. Furthermore, a mobile communication device may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto.

Figure 3 shows an example of a control apparatus for a communication system, for example to be coupled to and/or for controlling a station of an access system, such as a RAN node, e.g. a base station, (e) node B or 5G AP, or a node of a core network such as an MME or S-GW, or a server or host. The method may be implemented in a single control apparatus or across more than one control apparatus. The control apparatus may be integrated with or external to a node or module of a core network or RAN. In some embodiments, base stations comprise a separate control apparatus unit or module. In other embodiments, the control apparatus can be another network element such as a radio network controller or a spectrum controller. In some embodiments, each base station may have such a control apparatus as well as a control apparatus being provided in a radio network controller. The control apparatus 300 can be arranged to provide control on communications in the service area of the system. The control apparatus 300 comprises at least one random access memory 310, at least one read only memory 350 at least one

data processing unit

320, 330 and an input/output interface 340. Via the interface, the control apparatus can be coupled to a receiver and a transmitter of the base station. The receiver and/or the transmitter may be implemented as a radio front end or a remote radio head.

Devices typically communicate with each other via sending and receiving communications with the base station. However, another form of communication, known as device-to-device (D2D) communication, may be used. In D2D communication, data is exchanged between two devices without traversing the base station or the core network. Sidelink is an LTE feature introduced in 3GPP Release 12 aiming at enabling device-to-device (D2D) communications within legacy cellular-based LTE radio access networks. Sidelink enables the direct communication between proximal UEs using the newly defined PC5 interface, so that data does not need to traverse the eNB.

For example, referring back to Figure 1, a communication device 121 is shown exchanging D2D communications 122 with the device 105. These communications are exchanged between the devices, without being routed via the base station 116.

The sidelink D2D is applicable to public safety and commercial communication use-cases, and recently (in 3GPP Release 14) to vehicle-to-vehicle (V2V) scenarios and (in 3GPP Release 14) to vehicle-to-everything (V2X) scenarios.

During sidelink communications, it is desirable to reduce the probability of collisions. For example, if a first device and a second device are configured to perform transmissions on one or more of the same resources, the transmissions may interfere with one another leading to the receiving device failing to correctly receive the transmission from the sending device. For the sidelink communications for V2X, two transmission modes have been defined so as to reduce the probability of collisions. These modes may be referred to as “eNB-scheduled mode” (or mode 3) and “UE-autonomous mode” (or mode 4) . These modes are used to select transmission resources from a resource pool. A resource pool defines the subset of available subframes and resource blocks for either sidelink transmission or sidelink reception. Sidelink communication is a half-duplex scheme and a UE can be configured with multiple transmit resource pools and multiple receive resource pools. When data is to be sent using a resource pool, the actual transmission resources are selected dynamically or semi-persistently from within the pool using “eNB-scheduled mode” or “UE-autonomous mode” .

In eNB-scheduled mode, also known as mode 3, resources for D2D transmissions are scheduled by the eNB. UEs operating in eNB-scheduled mode are informed about their resource allocation by the eNB using physical layer signalling. The physical layer signalling may comprise Downlink Control Information (DCI) in format 5A. The scheduling in eNB-scheduled mode may either be dynamic or semi-persistent. In dynamic scheduling, a device has to request and the eNB has to grant resources separately for each transport block to be transmitted. In semi-persistent scheduling (SPS) , control information (e.g. DCI format 5A) may be sent by the base station to activate transmissions to be made periodically in a set of resources. The transmissions may occur in the same set of resources periodically without any further control information for scheduling the transmissions being received. The periodic transmissions on this set of resources may continue until the base station deschedules the periodic transmission (i.e. until the device making the transmissions is released) .

In UE-autonomous mode, also known as mode 4, on the other hand, devices autonomously select resources for sidelink transmissions. In other words, the devices themselves determine the scheduling for their D2D transmissions without being instructed as to the resources on which to transmit by the base station. A device performs the resource selection based upon sensing other devices′transmissions in order to avoid colliding with the resources on which nearby devices are transmitting. This mechanism relies on the assumption that the generation of most V2X traffic is approximately periodic in time and, as a result, transmissions can be periodic.

In 3GPP Release 15, the eV2X (enhanced Vehicle to Everything) work item includes the objective to specify solutions for the certain PC5 functionalities, which can co-exist in the same resource pools as Release 14 functionality and use the same scheduling assignment format (which can be decoded by Release 14 devices) , without causing significant degradation to Release 14 PC5 operation compared to that of Release 14 devices. The PC5 functionalities may comprise carrier aggregation of up to 8 PC5 carriers; 64 Quadrature Amplitude Modulation; a reduced maximum time between arrival of a packet at layer 1 and selection of resources for transmission; and radio resource pool sharing between devices using eNB-scheduled mode and devices using UE-autonomous mode.

As part of the carrier aggregation feature, it has been agreed to enhance packet delivery reliability for V2X it was agreed to support PDCP duplication over two carriers with configured V2X sidelink resources. The details are illustrated by the 3GPP agreements shown in Annex A.

In order to improve the reliability of device to device transmissions between devices, a first device may be configured to transmit duplicate packets to a second device. One issue that has arisen is how to control the packet duplication so as to utilise available resources efficiently. A QoS parameter referred to as ProSe Per-Packet Reliability (PPPR) has been introduced. This parameter is defined and set by the application layer for each corresponding packet that is delivered from application layer to the access stratum for transmission over PC5 interface. The PPPR is passed from the application layer to the packet data convergence protocol (PDCP) layer along with the corresponding packet (which is a service data unit of the PDCP) at the transmitting device. The PPPR values may be used to enable/disable the packet duplication.

One proposal to enable/disable packet duplication for device to device communications in eNB-scheduled mode is to use either or both of Radio Resource Control (RRC) signalling or Medium Access Control (MAC) Control Element signalling to configure the PPPR values and/or value-range and/or value threshold for controlling the packet duplication. Based on the configured PPPR values and/or value range and/or value threshold, the device determines whether or not to perform a duplicate transmission of a packet. The device compares the PPPR value of a packet delivered from the upper layer for transmission to the configured PPPR value and/or value range and/or configured PPPR value threshold to determine whether or not to perform a duplicate transmission of the packet. For example, this may involve determining to perform a duplicate transmission of a packet if the set PPPR of the packet is among the configured PPPR values or value range. Additionally or alternatively, this may involve determining to perform a duplicate transmission if the set PPPR of the packet is above the configured PPPR value threshold.

However, there remain issues with the above mentioned proposal. Firstly, in the case that there are more than 2 carriers that may be used for sidelink carrier-aggregation based transmissions between two devices, there is no indication provided by the base station as to which carrier should be used for the packet duplication, i.e. there is no indication of which carriers should be used for transmission of the original packet and the duplicate packet.

Secondly, it is not clear how the buffer status report (BSR) related to the packet duplication should be reported to the network. The buffer status report, which may be a MAC Control Element, is sent from the transmitting device to the base station and provides an indication of the amount of data to be sent by the device. In response to receiving the buffer status report, the network may allocate the resources required to the device to enable it to perform the transmission. The sidelink BSR is sent to the same base station that allocates the resources. However, the original and duplicated D2D packets are transmitted on separate carriers. Therefore, the base station unaware as to whether the reported sidelink BSR for a carrier corresponds to the duplicated data or not.

One proposal for the BSR for packet duplication involves including carrier information in the BSR, indicating the carrier that the device requests transmission of duplicate data packets for. This proposal would operate under the assumption that the device knows on which carriers the original and duplicate packets should be transmitted. Since, for sidelink communications, packet duplication on a single carrier is not supported (i.e. the original packet and the duplicate packet must be transmitted on separate carriers) in the case that there are more than two carriers, a selection of a carrier on which transmission of a duplicate packet is to be performed must be made. If the selection of the carriers for packet duplication is pre-configured, this may result in a less efficient utilisation of the available carriers. Such pre-configured carriers for packet duplication may be less dynamic and involve less efficient utilisation of the available carriers, as compared to a more dynamically controlled option which may adapt to e.g. the actual load of each carrier.

Another proposal is to only report the BSR for one carrier so that no duplication indication need be included in the BSR. In this proposal, the base station may make the decision as to whether or not packet duplication is to be performed and on which carrier the original and duplicated packets are to be transmitted if duplication is activated.

The use of semi-static packet duplication activation/deactivation configurations has been proposed, which can be applied for both eNB-scheduled mode and UE-scheduled mode operation. However, a semi-static configuration may fail to adapt to the real traffic and carrier conditions.

Certain Logical Channel Prioritisation (LCP) restrictions specified in NR (New Radio) may be used to limit the usage of a particular numerology and/or transmission timing to a subset of the logical channels configured. However, this is, as for the proposal mentioned above, controlled and configured by the RRC signalling and is not performed on a per grant basis.

Embodiments of the application may address the above mentioned issues by having the base station dynamically controlling whether or not packet duplication is enabled and controlling the carriers for which packet duplication is performed if enabled. The base station is aware of the load placed on each carrier (at least for eNB-scheduled mode operation) . The base station, for example, may determine the load placed on each carrier based upon one or more of: the reported Channel Busy Ratios (CBRs) of each carrier (which are measured and reported by selected communication devices on certain carrier/s) ; the BSRs received from all the devices to which it is connected; and the corresponding carriers that each BSR is associated with as well as allocated semi-persistent scheduling (SPS) resources. Therefore, the base station is in a strong position to dynamically control packet duplication by providing an indication for each logical channel group as to whether or not packet duplication should be performed. The base station may also provide an indication as to the carrier on which the duplicate packet should be transmitted. By having the base station dynamically control packet duplication, the above mentioned proposal in which the BSR is modified to include an indication of a carrier for the duplicate packet transmission may not be needed.

According to embodiments of the application, to introduce more dynamic packet duplication control in eNB-scheduled mode operation, e.g. based on the resource usage condition and exploit the dynamic cooperation of eNB-scheduled mode and UE-schedule mode operation, embodiments provide dynamic control of D2D packet duplication on a per Logical Channel Group (LCG) and per grant basis.

Reference is made to Figure 4, which illustrates a communication system 400 according to embodiments of the application. The communication system comprises a base station 405. The base station 405 is connected to a core network (not shown) . The base station 405 is configured to communicate with a first device 410. The first device 410 is configured to perform device to device communication with a second device 415. The first device 410 and/or second device 415 may be vehicle user equipment.

The packet duplication may be determined and controlled by the base station 405 for a given LCG. A Logical Channel Group is a group of logical channels for which buffer status is reported. In LTE, there are 4 LCGs and each has its own ID from 0 to 3. Since keeping the eNB informed of the status of a large number of radio bearers (each corresponding to a logical channel) requires considerable signalling overhead, the logical channels are grouped in this way such that a status report (BSR) can be sent for each group, as opposed to for each logical channel.

Since the packet duplication may be determined and controlled for a given LCG, the grant message 420 may comprise an indication of the LCG for which the packet duplication is enabled or disabled. Since, the status is reported for an LCG, the base station enables/disables the packet duplication for each LCG. In some examples, packet duplication may be preconfigured for a specific LCG. In this case, the grant message 420 may omit the indication of the LCG.

The determination as to whether or not to enable or disable the duplicate transmission may be based on the carriers that are associated with the LCG. For instance, carriers may be selected based on their channel busy ratios (CBR) . The carriers with a lower CBR may be prioritised for selection. The two carriers with the lowest CBR may be selected for transmission of the original packet and the duplicate packet. The determination may be based on the resource pool usage status and/or CBR in the corresponding carriers. The resource pool usage status may comprise UE-autonomous mode and eNB-scheduled mode resource pool usage status. For instance, the duplication may be activated only if the CBR is lower than certain threshold. The determination may be based on the received BSR for the LCG. The determination may be based on reliability information (e.g. the PPPR) and/or packet priority information (e.g. the ProSe per packet priority (PPPP) ) corresponding to the LCG in the BSR. For instance, the duplication may be activated if the LCG reported in BSR is associated with predetermined reliability information and/or predetermined packet priority information.

The base station 405 may be configured to communicate with a plurality of communication devices other than those shown. The base station 405 receives a plurality of buffer status reports from the plurality of communication devices. Using the buffer status reports, the base station 405 may determine the load on different transmission resources. The base station 405 may, therefore, use the buffer status reports to determine whether to enable or disable packet duplication for a logical channel group. The base station 405 may also use the buffer status reports to select a first at least one resource for performing a transmission of a duplicate data packet.

The base station 405 may also receive a buffer status report from the device 410. The buffer status report is associated with the logical channel group for which an indication is included in the grant message. This buffer status report may be used to determine to enable packet duplication for the logical channel group.

The base station (or a control apparatus of the base station) is configured to transmit a grant message 420 to a device 410. The grant message 420 comprises an indication that a duplication transmission is to be performed for a logical channel group. The grant message 420 may comprise an indication of a carrier in which the duplicate packet is to be transmitted. The grant message 420 may be a sidelink grant message.

The first device 410 is configured to receive the grant message 420. The first device 410 duplicates a packet that is to be transmitted to the second device 415 to produce an original packet and a duplicate packet. It should be appreciated that, although, in the application, the packets are referred to as “original” and “duplicate” , the packets may be identical, such that either packet could be considered to be the original or the duplicate.

The grant message 420 may be sent in the physical downlink control channel (PDCCH) .

The grant message 420 may be a grant message for the carrier in which the duplicate data packet is to be transmitted. The first device 410 that receives the grant message 420 may determine from the indication of the LCG in the grant message, the data that is to be duplicated and transmitted in the carrier.

The first device 410 is configured to transmit the original packet using a first at least one resource 425 via a device to device transmission. The first at least one resource 425 belongs to the logical channel group indicated in the grant message 420. The first device 410 is also configured to transmit the duplicate packet to the second device 415 on a second at least one resource 430 that is also part of the logical channel group indicated in the grant message 420. The second at least one resource 430 may belong to a carrier indicated in the in the received grant message 420. The first at least one resource 430 and the second at least one resource 425 may belong to different carriers.

In some examples, the first device 410 may transmit both the original data packet and the duplicate data packet using eNB-scheduled mode transmission. In some examples, the first device 410 may transmit the original data packet using eNB-scheduled mode transmission, whilst transmitting the duplicate data packet using UE-autonomous mode transmission.

In some examples, the grant message 420 may comprise an indication of the second at least one resource 430 on which the duplicate data packet is to be transmitted. The first device 410 is configured to transmit the duplicate data packet on the second at least one resource 430. This transmission is, therefore, made in eNB-scheduled mode.

In some examples, the device 410 is configured to autonomously select resources for transmission of the duplicate data packet. The grant message 420 may comprise an instruction to the device to autonomously select transmission resources for transmission of the duplicate data packet. The grant message 420 may be an instruction to autonomously select resources from the carrier indicated in the grant message. The device 410 may be configured to receive the instruction and to autonomously select the resources from the carrier 430. In some cases, the grant message 420 may indicate the carrier 425 from which resources are to be selected. In other cases, the device 410 may be configured to autonomously select both the carrier and the resources. The device 410 may autonomously select the second at least one resource 430. The device 410 may then transmit the duplicate data packet on the second at least one resource 430. This transmission is, therefore, made in UE-autonomous mode.

In the case that the device is configured to transmit the duplicate packet in eNB-scheduled mode, the base station 405 may transmit to the first device 410 a grant message for the carrier in which the original data packet is transmitted and a grant message for the carrier in which the duplicate data packet is transmitted. The indication that duplication is enabled for the LCG to which these two carriers belong may be included in either or both of these grant messages. The grant message for the original data packet and the grant message for the duplicate data packet may contain redundant versions of the coding scheme. The two grant messages may contain redundant indications that duplicate transmission is enabled for the LCG.

In the case that the device is configured to transmit the duplicate packet in UE-autonomous mode, the base station 405 may transmit to the first device 410 a single grant message for the carrier in which the original data packet is transmitted. The indication that duplication is enabled for the LCG to which the carriers in which the original and duplicate packets are transmitted is included in this grant message. This grant message includes an indication that the duplicate packet is to be transmitted in autonomously selected resources and optionally includes an indication of the carrier from the resources are to be autonomously selected.

Reference is made to Figure 5, which illustrates the messages passed between the base station 505 and the first communication device 510. In the diagram 500, the base station 505 is shown as an eNB, but may be another form of base station. The first communication device 510 is shown as a VUE, but may be another form of communication device.

The base station 505 transmits to the device 510, a message comprising an indication of the mapping of PPPP and/or PPPR to the LCG. The message may be an RRC_Reconfiguation message for example. Additionally or alternatively, MAC CE based signalling may be used to provide this indication.

The base station 505 may configure the PPPP and PPPR to LCG mapping in such a way that data reported in one or more LCGs may be selected and indicated by the base station as being for duplication. This mechanism may incorporate flexible mapping on PPPP and PPPR onto LCG mapping and thus provide better control over the packet duplication.

The device 510 transmits to the base station a buffer status report. The buffer status report may be a report for a particular LCG. The buffer status report includes at least one of an indication of the Logical Channel Group, an indication of the data buffer for which status is reported, and a destination index. Since the base station configures the PPPP and PPPR to LCG mapping, the base station can determine whether or not to enable duplicate transmission based on the LCG indication without the need for the explicit PPPR and PPPP values to be included in the buffer status report.

The base station 505 receives the status report and determines whether or not to enable duplication of data for an LCG. The determination may be based on at least one of the reliability information; the packet priority information associated with or mapped on the LCG in the status report; and information from BSRs of other devices in communication with the base station 505. The base station 505 may determine whether the duplicate data is to be transmitted in eNB-scheduled mode or UE-autonomous mode. The base station 505 may select a carrier for transmission of a duplicate data packet by the first device. The selection of the carrier may be made on the basis of the status reports provided by a plurality of devices. The selection may be made so as to spread the load over different carriers.

The base station 505 transmits to the communication device 510, the grant message. The grant message comprises an indication that duplication is enabled for the LCG indicated in the grant message. The grant message may comprise an instruction to the device 510 to autonomously select resources in which to perform the transmission of the duplicate packet. The grant message may comprise an indication of a carrier from which resources for performing the transmission of the duplicate packet are to be selected. The grant message may comprise an indication of second at least one resource in which the duplicate packet should be transmitted.

The communication device 510 receives the grant message and performs duplicate transmission for data packets belonging to the logical channel group indicated in the grant message. The device 510 performs a transmission of a duplicate packet on the resources indicated in the grant message (when operating in eNB-scheduled mode) and on resources autonomously selected by the device (when operating in UE-autonomous mode) . The grant message may provide an indication as to the mode to be used for determining the resources on which the transmission is to be made.

Since the LCG is indicated in the grant message, the logical channel prioritisation (LCP) in the device 510 may also take into account the LCG indicated in the grant. The LCP may be in the MAC layer of the device 510. For example, when the device 510 receives the grant message 420 indicating that packet duplication is to be performed for a specified LCG, the device should prioritise the data corresponding to the indicated LCG to transmit the duplicate data in the carrier indicated in the grant message 420.

The proposed dynamic control of D2D packet duplication via the scheduled grant from the serving base station can be applied together with the semi-static mapping of PPPP and/or PPPR on LCG for duplication control (e.g. via RRC signalling or a MAC control element) as discussed above. For instance, the device can determine to enable packet duplication based on PPPR values that may be configured by RRC signalling or MAC control element signalling. However, the duplicate packet transmission will be performed only if the grant message includes the indication that duplication is to be performed. Otherwise, the duplicate packets will be deleted from the transmission buffer.

Reference is made to Figure 6, which illustrates an example of a method that may be performed in a communication device according to embodiments of the application.

At S605, the device transmits a buffer status report to the base station. The buffer status report is a buffer status report for an LCG. The buffer status report implicitly indicates the reliability information and/or packet priority information associated with the LCG based on the configuration received from the base station.

At S610, the device receives a grant message for D2D communication from the base station. The grant message indicates that duplicate transmission is enabled for the LCG for which the buffer status report is transmitted. The grant message may also indicate whether or not the transmission of a duplicate data packet should be carried out in resources selected autonomously by the device or in resources specified in the grant message itself.

At S615, if the grant message indicates that the transmission is to take place in resources specified in the message, the method proceeds to S620. At S620, the device transmits the duplicate data packet on the second at least one resource indicated in the grant message. The device also transmits the original packet in a first at least one resource. Both the second at least one resource and the first at least one resource are associated with the logical channel group indicated in the grant message.

If the grant message indicates that transmission is to take place on resources autonomously selected by the device, the method proceeds to S625. At S625, the device autonomously selects resources and performs the transmission of the duplicate data packet on the selected second at least one resource. The grant message may optionally include an indication of a carrier associated with the logical channel group from which the resources are to be selected by the device. The device may then select the resources from this carrier. The device also transmits the original packet in a first at least one resource. Again, both the second at least one resource and the first at least one resource are associated with the logical channel group indicated in the grant message.

Reference is made to Figure 7, which illustrates a method 700 according to examples of the application.

At S705, the base station receives a plurality of buffer status reports from a plurality of communication devices. Included in the plurality of buffer status reports is a buffer status report associated with a logical channel group from a first communication device.

At S710, the base station determines to enable packet duplication for the logical channel group for the first communication device. The determination may be made on the basis of the plurality of buffer status reports. The determination may be made on the basis of reliability and/or packet priority information in the buffer status report associated with the logical channel group from the first communication device.

At S715, the base station determines whether or not the duplicate packet is to be transmitted in resources indicated in the grant message or in resources autonomously selected by the device.

At S720, the base station transmits the grant message comprising the indication that duplicate packet transmission is enabled for the data packet. The grant message also includes the indications as to the mode of transmission (i.e. eNB-scheduled mode or UE-autonomous mode) that were determined in S715.

It should be understood that each block of the flowcharts of Figures 6 and 7 and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and/or circuitry.

The methods may be implemented on a mobile device as described with respect to Figure 2 or control apparatus as shown in Figure 3.

Control functions may comprise receiving a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group; causing a device to device communication transmission of a data packet that is part of the logical channel group in a first at least one resource; and in response to the indication, causing a device to device communication transmission of a duplicate of the data packet that is part of the logical channel group in a second at least one resource.

Additionally or alternatively, control functions may comprise: transmitting to a communication device, a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group.

It should be understood that the apparatuses may comprise or be coupled to other units or modules etc., such as radio parts or radio heads, used in or for transmission and/or reception. Although the apparatuses have been described as one entity, different modules and memory may be implemented in one or more physical or logical entities.

It is noted that whilst embodiments have been described in relation to LTE/LTE-A/Sidelink, similar principles can be applied in relation to other networks and communication systems. For example, the principles may be applies to devices operating using multi-connectivity. Therefore, although certain embodiments were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, embodiments may be applied to any other suitable forms of communication systems than those illustrated and described herein.

It is also noted herein that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The embodiments of this invention may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and/or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out embodiments. The one or more computer-executable components may be at least one software code or portions of it.

Further in this regard it should be noted that any blocks of the logic flow as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media. An example of a non-transitory computer readable medium 800 is shown in Figure 8. The non-transitory computer readable medium 800 may be a CD or DVD.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) , application specific integrated circuits (ASIC) , FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims.

However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention as defined in the appended claims. Indeed there is a further embodiment comprising a combination of one or more embodiments with any of the other embodiments previously discussed.

ANNEX A

Agreements in RAN2#100

1 Sidelink packet duplication in LTE is anchored at PDCP.

2 As for the Uu packet duplication, duplicated sidelink PDCP PDUs are submitted to two different RLC entities and associated to two different logical channels.

3 As for the Uu packet duplication, sidelink packet duplication on a single carrier is not supported, i.e. the MAC layer cannot multiplex the two logical channels associated to a duplicate packet into the same HARQ entity.

4 The LCID (s) that can be used for transmission of one replica of a duplicate packet are reserved, i.e. they cannot be used by non-duplicated packet transmission. RAN2 to discuss whether this LCID (s) for the duplicated packet should be (pre) configured or hard-coded or up to the UE implementation. (FFS (pre) configuration or hard-coded or up to the UE implementation. Option should be worked for both mode3 and mode4. )

5 Will ask SA2 the possibility to derive reliability information. Will include some background information for packet duplication and the benefits of reliability indication. Includes background information of Rel-14 PPPP.

Agreements in RAN2#100:

1. For mode4 (connected and idle) , UE autonomous activation of duplication transmission on multiple carriers is allowed based on (pre) configuration. FFS on UE request to NW for duplication transmission.

Agreements in RAN2#101:

- RAN2 confirm that eNB needs to be made aware of the PPPR information

- Define PPPR as 4 levels or 8 levels

- RAN2 confirm that it is beneficial to apply reliability to all V2X messages

- PDCP performs packet duplication detection in Rx UE

- Working assumption: Option1 (Hard-coded mapping between original LCID and duplicate) unless it brings big problem

Claims

An apparatus comprising means for:

receiving a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group;

causing a device to device communication transmission of a data packet that is part of the logical channel group in a first at least one resource; and

in response to the indication, causing a device to device communication transmission of a duplicate of the data packet that is part of the logical channel group in a second at least one resource.
An apparatus as claimed in claim 1, wherein the grant message comprises an instruction to autonomously select resources, the apparatus comprising means for in response to the instruction, autonomously selecting the second at least one resource.
An apparatus as claimed in claim 2, wherein the grant message comprises an indication of a carrier, the apparatus comprising means for, in response to the indication, autonomously selecting the second at least one resource from the carrier.
An apparatus as claimed in any preceding claim, wherein the device to device communication grant message provides a grant for a carrier comprising the first at least one resource.
An apparatus as claimed in claim 1, wherein the device to device communication grant message comprises an indication of the second at least one resource, the apparatus comprising means for, in response to the indication of the second at least one resource, causing the device to device communication transmission of the duplicate of the data packet in the second at least one resource.
An apparatus as claimed in either of claim 1 or claim 4, wherein the device to device communication grant message provides a grant for a carrier comprising the second at least one resource.
An apparatus as claimed in any preceding claim, wherein the first at least one resource and the second at least one resource belong to different carriers.
An apparatus comprising means for transmitting to a communication device, a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group.
An apparatus as claimed in claim 8, wherein the grant message comprises an instruction to autonomously select resources.
An apparatus as claimed in either claim 8 or claim 9, wherein the indication comprises an indication of a carrier on which the duplicate transmission is to be made.
An apparatus as claimed in any of claims 8 to 10, wherein the device to device communication grant message comprises a grant for a carrier in which an original transmission corresponding to the duplicate transmission is to be made by the communication device.
An apparatus as claimed in claim 1, wherein the indication comprises an indication of a second at least one resource on which the duplicate transmission is to be made.
An apparatus as claimed in either claim 8 or claim 12, wherein the device to device communication grant message provides a grant for a carrier in which the duplicate transmission is to be made.
An apparatus as claimed in any of claims 8 to 13, comprising means for:

receiving from a plurality of communication devices, a plurality of buffer status reports; and

determining from the plurality of buffer status reports, to enable the duplicate transmission for the logical channel group.
An apparatus as claimed in any of claims 8 to 14, comprising means for determining to enable the duplicate transmission for the logical channel group in dependence upon a load of one or more carriers associated with the logical channel group.
An apparatus as claimed in any preceding claim, wherein the grant message comprises an identifier of the logical channel group.
A computer program product for a computer, comprising software code portions for performing a method when said product is run on the computer, the method comprising:

receiving a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group;

causing a device to device communication transmission of a data packet that is part of the logical channel group in a first at least one resource; and

in response to the indication, causing a device to device communication transmission of a duplicate of the data packet that is part of the logical channel group in a second at least one resource.
A computer program product for a computer, comprising software code portions for performing a method when said product is run on the computer, the method comprising:

transmitting to a communication device, a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group.
An apparatus comprising:

at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

receive a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group;

cause a device to device communication transmission of a data packet that is part of the logical channel group in a first at least one resource; and

in response to the indication, cause a device to device communication transmission of a duplicate of the data packet that is part of the logical channel group in a second at least one resource.
An apparatus comprising:

at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

transmit to a communication device, a device to device communication grant message comprising an indication that duplicate transmission is enabled for a logical channel group.