WO2020077560A1

WO2020077560A1 - L1 signaling for serving cells

Info

Publication number: WO2020077560A1
Application number: PCT/CN2018/110644
Authority: WO
Inventors: Tao Yang; Karol Schober
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2018-10-17
Filing date: 2018-10-17
Publication date: 2020-04-23
Also published as: CN112868261B; CN112868261A

Abstract

Example embodiments of the present disclosure relate to devices, methods, apparatuses and computer readable storage media for scheduling and activating serving cells using Layer 1 (L1) signaling. In example embodiments, a first indication of a first set of active serving cells from a plurality of serving cells is sent by a network device to a terminal device in a first L1 signaling message. A second indication of a second set of active bandwidth parts for the first set of active serving cells is sent to the terminal device in a second L1 signaling message. A third indication of a third set of scheduled active serving cells from the first set of active serving cells is sent to the terminal device in a third L1 signaling message.

Description

L1 SIGNALING FOR SERVING CELLS

FIELD

Embodiments of the present disclosure generally relate to the field of communications, and in particular, to devices, methods, apparatuses and computer readable storage media for scheduling and activating serving cells using Layer 1 (L1) signaling.

BACKGROUND

In the standardization of the 3rd Generation Partnership Project (3GPP) Radio Access Network (RAN) , it is approved to enhance the Carrier Aggregation (CA) and Dual Connectivity (DC) functionality of New Radio (NR) . One of the objectives is to fasten activation and de-activation of serving cells, Bandwidth Part (BWP) switching and corresponding scheduling. For example, the efficiency and low latency of serving cell configuration, activation and setup may be enabled by minimizing signaling overhead and latency induced in L1, Layer 2 (L2) or Layer 3 (L3) during initial cell setup, additional cell setup or additional cell activation for data transmission. This objective is applied in various scenarios of Multi-RAT (Radio Access Technology) DC, NR-NR DC, CA and the like. The enhancements may be achieved in IDLE, INACTIVE and CONNECTED modes.

To reduce activation delay of serving cells in NR L1 layer, activation and de-activation of serving ceils based on downlink control information (DCI) are proposed to replace conventional activation and de-activation of the serving cells based on Media Access Control (MAC) Control Elements (CEs) as used in Long Term Evolution (LTE) . However, no effective and efficient L1 signaling design is presented.

SUMMARY

In general, example embodiments of the present disclosure provide devices, methods, apparatuses and computer readable storage media for scheduling and activating serving cells using L1 signaling.

In a first aspect, a device is provided comprising at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the device to send, by a network device to a terminal device, a first indication of a first set of active serving cells from a plurality of serving cells in a first L1 signaling message. The device is also caused to send, to the terminal device, a second indication of a second set of active bandwidth parts for the first set of active serving cells in a second L1 signaling message. The device is further caused to send, to the terminal device, a third indication of a third set of scheduled active serving cells from the first set of active serving cells in a third L1 signaling message.

In a second aspect, a device is provided comprising at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the device to receive, by a terminal device from a network device, a first indication of a first set of active serving cells from a plurality of serving cells in a first L1 signaling message. The device is also caused to receive, from the network device, a second indication of a second set of active bandwidth parts for the first set of active serving cells in a second L1 signaling message. The device is further caused to receive, from the network device, a third indication of a third set of scheduled active serving cells from the first set of active serving cells in a third L1 signaling message.

In a third aspect, a method is provided. In the method, a first indication of a first set of active serving cells from a plurality of serving cells is sent by a network device to a terminal device in a first L1 signaling message. A second indication of a second set of active bandwidth parts for the first set of active serving cells is sent to the terminal device in a second L1 signaling message. A third indication of a third set of scheduled active serving cells from the first set of active serving cells is sent to the terminal device in a third L1 signaling message.

In a fourth aspect, a method is provided. In the method, a first indication of a first set of active serving cells from a plurality of serving cells is received by a terminal device from a network device in a first L1 signaling message. A second indication of a second set of active bandwidth parts for the first set of active serving cells is received from the network device in a second L1 signaling message. A third indication of a third set of scheduled active serving cells from the first set of active serving cells is received from the network device in a third L1 signaling message.

In a fifth aspect, there is provided an apparatus comprising means for performing the method according to the third or fourth aspect.

In a sixth aspect, there is provided a computer readable storage medium that stores a computer program thereon. The computer program, when executed by a processor of a device, causes the device to perform the method according to the third or fourth aspect.

It is to be understood that the summary section is not intended to identify key or essential features of example embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

FIG. 1 illustrates an example environment in which example embodiments of the present disclosure can be implemented;

FIG. 2 illustrates a flowchart of an example method in accordance with some example embodiments of the present disclosure;

FIG. 3 illustrates an example process of transmitting two L1 signaling messages to indicate the active or de-active status of the serving cells and the corresponding BWPs and resources in accordance with some example embodiments of the present disclosure;

FIG. 4 illustrates a flowchart of an example method in accordance with some other example embodiments of the present disclosure;

FIG. 5 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodirnents are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

As used herein, the term “network device” refers to any suitable device at a network side of a communication network. The network device may include any suitable device in an access network of the communication network, for example, including a base station (BS) , a relay, an access point (AP) , a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NodeB (gNB) , a Remote Radio Module (RRU) , a radio header (RH) , a remote radio head (RRH) , a low power node such as a femto, a pico, and the like.

As used herein, the term “terminal device” refers to a device capable of, configured for, arranged for, and/or operable for communications with a network device or a further terminal device in a communication network. The communications may involve transmitting and/or receiving wireless signals using electromagnetic signals, radio waves, infrared signals, and/or other types of signals suitable for conveying information over air. In some example embodiments, the terminal device may be configured to transmit and/or receive information without direct human interaction. For example, the terminal device may transmit information to the network device on predetermined schedules, when triggered by an internal or external event, or in response to requests from the network side.

Examples of the terminal device include, but are not limited to, user equipment (UE) such as smart phones, wireless-enabled tablet computers, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , and/or wireless customer-premises equipment (CPE) . For the purpose of discussion, some example embodiments will be described with reference to UEs as examples of the terminal devices, and the terms “terminal device” and “user equipment” (UE) may be used interchangeably in the context of the present disclosure.

As used herein, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) : (i) a combination of analog and/or digital hardware circuit (s) with software/finnware and (ii) any portions of hardware processor (s) with software (including digital signal processor (s)) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the singular forms “a” , “an” , and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to” . The term “based on” is to be read as “based at least in part on” . The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment” . The term “another embodiment” is to be read as “at least one other embodiment” . Other definitions, explicit and implicit, may be included below.

Conventionally, MAC CEs in LTE are used to activate and de-activate a serving cell in NR for the trade-off between fast signaling transmission and signaling accuracy, for example. Compared to LTE, the latency requirement is more critical in NR. As a result, MAC CEs in LTE seem not to be fast enough due to longer L2 signaling caused, for example, by multiple Hybrid Automatic Repeat request (HARQ) retransmissions or necessary communications between different layers, such as L1 or a physical (PHY) layer and L2 or a MAC layer) . It has already been proposed to leverage L1 signaling such as DCI to fasten the activation and de-activation of the serving cell. However, there is no effective and efficient L1 signaling design to support it.

In the fifth generation (5G) NR, a BWP concept is specified to allow a wide bandwidth as well as different user equipment (UE) capabilities. Up to 4 BWPs may be potentially configured for a NR serving cell. At most one BWP is active for data transmission per serving cell. For example, upon the activation of a serving cell, a predefined BWP of the serving cell, configured in a higher layer such as L2 or L3, becomes active.

The switching or activation of BWPs based on DCI has been defined to enable data transmission on different BWPs of a serving cell at different time slots. These BWPs may be jointly scheduled or activated. However, such joint scheduling and activation may not be applied to the case where the multiple active BWPs are active in multiple serving cells, one active BWP in one active serving ceil.

Embodiments of the present disclosure provide a novel L1 signaling design to enable simultaneous activation (or de-activation) , scheduling of serving cells and BWP switching. At a network device side, an indication of active serving cells is sent to a terminal device in a L1 signaling message. The L1 signaling message may be sent in any of the active serving ceils. For the active serving cells, an indication of corresponding active BWPs (one active per serving cell) is sent to the terminal device in this L1 signaling message or a different L1 signaling message. An indication of scheduled ones of the active serving cells is further sent to the terminal device. The indication of the scheduled active serving cells may be sent together with the indication of the active BWPs. Accordingly, at a terminal device side, active or de-active status of the serving cells, the active BWPs for the active serving cells and the scheduled or non-scheduled status of the active serving cells can be determined based on the indications received in the L1 from the network device.

In this way, the activation and de-activation of the serving cells and the corresponding BWPs activation/switching/scheduling may be combined. Fast data transmission may be enabled by fast and efficient activation or de-activation of the serving cell (s) and BWP operations. The delay is far shorter compared with the conventional MAC CE-based activation/de-activation operation of serving cells. Thus, fast data transmission requirement may be met. Moreover, signaling overhead for the activation or de-activation of the serving cells and BWPs may be reduced, and therefore higher signaling efficiency may be achieved. In addition, with L1 signaling, the scheduling of the active serving may be more flexible or dynamic.

FIG. 1 shows an example environment 100 in which example embodiments of the present disclosure can be implemented. The environment 100, which may be a part of a communication network, comprises a network device 110 and a terminal device 120. It is to be understood that one network device 110 and one terminal device 120 are shown in the environment 100 only for the purpose of illustration, without suggesting any limitation to the scope of the present disclosure. The environment 100 may include any suitable number of network devices and terminal devices adapted for implementing example embodiments of the present disclosure.

The terminal device 120 can communicate with the network device 110 or with another terminal device (not shown) directly or via the network device 110. The communication may follow any suitable communication standards or protocols such as Universal Mobile Telecommunications System (UMTS) , long term evolution (LTE) , LTE-Advanced (LTE-A) , the fifth generation (5G) NR, Wireless Fidelity (Wi-Fi) and Worldwide Interoperability for Microwave Access (WiMAX) standards, and employs any suitable communication technologies, including, for example, Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiplexing (OFDM) , time division multiplexing (TDM) , frequency division multiplexing (FDM) , code division multiplexing (CDM) , Bluetooth, ZigBee, and machine type communication (MTC) , enhanced mobile broadband (eMBB) , massive machine type communication (mMTC) and ultra-reliable low latency communication (URLLC) technologies.

In the environment 100, the network device 110 by itself or together with other network devices (not shown) can provide a plurality of serving cells. In the CA scenario, different serving cells may operate on different carriers. These serving cells may be available to the terminal device 120 for communication.

In various example embodiments of the present disclosure, for the terminal device 120, some of the serving cells are active, and others are de-active. The terminal device 120 can transmit or receive data in the active serving cells. Moreover, in any of the active serving cells, the terminal device 120 can receive at least one L1 signaling message from the network device 110. The L1 signaling message may comprise any suitable signaling message in L1 or the PHY layer, such as a DCI message. Using the L1 signaling, the activation or de-activation of the serving cells, the activation of the corresponding BWPs and the scheduling of the active serving cells may be more fast and flexible.

FIG. 2 illustrates a flowchart of an example method 200 in accordance with some example embodiments of the present disclosure. The method 200 can be implemented by the network device 110 as shown in FIG. 1. For the purpose of discussion, the method 200 will be described with reference to FIG. 1.

At block 205, the network device 110 sends to the terminal device 120 an indication (referred to as a first indication) of a set (referred to as a first set) of active serving cells from a plurality of serving cells in one of one or more L1 signaling messages (referred to as a first L1 signaling message) . The first L1 signaling message may be sent in any of the active serving cells.

The first indication can identify which one of the serving cells will be in active status for potential data scheduling. In some example embodiments, the first indication may only identify active serving cells among serving cell configured for the terminal device 120. In some other example embodiments, the first indication may identify active or de-active status of each serving cell configured for the terminal device 120.

The first indication may be implemented in any suitable format. In some example embodiments, the first indication may be contained in an Information Element (IE) (referred to as a first IE) of the first L1 signaling message. The first IE may comprise a plurality of bits indicating active or de-active status of different serving cells. The bits corresponding to the different serving cells may be ordered according to the corresponding carrier indication field (CIF) sequence of the serving cells.

A plurality of serving cells may be activated for the terminal device 120 in the CA scenario, and therefore these serving cells may be in active status simultaneously. Accordingly, in the example embodiments where the first indication identifies only the active serving cells, a size (or length) of the first IE may be variable depending on the number of actually/currently active serving cells. At the terminal device 120, blind decoding (BD) may be performed to detect the first IE, as will be detailed in the following paragraphs with reference to FIG. 4.

In the example embodiments where the first indication identifies active or de-active status of each serving cell, the first IE may have a predetermined size or length, such as a predetermined number of bits. Each of the bits is used to indicate the active or de-active status of the respective serving cell of the configured serving cells. The predetermined size may be indicated by the network device 110 in a higher layer signaling message, such as a Radio Resource Control (RRC) signaling message. For example, the network device 110 may use the higher layer signaling message to transmit an explicit indication of the predetermined size to the terminal device 120. As another example, the indication may be implicit. For example, the network device 110 may use other higher layer signaling, for example, for indicating the number of configured cells to implicitly indicate the predetermined size. It is also possible to specify the predetermined size, for example, as the maximum number of cells or carriers allowed for a terminal device in the communication network, based on the terminal device capability. As an alternative example, the predetermined size may be determined as the maximum number of cells supported by the communication network in CA, for example, specified in the related standards.

The configured serving cells may comprise a primary cell (Pcell) and a set of secondary cells (Scell) where the Pcell is generally in active status. In this case, the first set of active serving cells indicated by the first indication may include only the active secondary cells. For example, one bit for the Pcell may be skipped or omitted in the first IE to further reduce the overhead. It is also possible to reserve such a bit in the first IE to align with the Scells. In this situation, this bit may always be set to indicate the active status of the Pcell.

At block 210, the network device 110 sends to the terminal device 120 an indication (referred to as a second indication) of a set (referred to as a second set) of active BWPs for the first set of active serving cells in one of the one or more L1 signaling messages (referred to as a second L1 signaling message) . The second L1 signaling message may or may not be different from the first signaling message. The second indication may be used to switch (or activate) at least one BWP for each active serving cell, for example, for DL measurement and/or data transmission.

In some example embodiments, the second indication may be sent in another IE (referred to as a second IE) of the second L1 signaling message. In some implementations, the second IE may consist of a number of BWP fields. Each of the BWP fields corresponds to an active serving cell and indicates at least one BWP activated for the active serving cell.

In some example embodiments, each BWP field may include a number (for example, N) of bits. N is a positive integer and may depend on the number of BWPs allowed based on capability of a terminal device or based on configured number of BWPs for a serving cell for a terminal device. For example, in the case that one of up to four configured BWPs is active for one active serving cell, 2-bit BWP field may be used.

In some example embodiments, the number of BWP fields may be associated with the number of the active serving cells. By the number of the active serving cells or the size of the first IE containing the first indication, the network device 110 may implicitly indicate the number of BWP fields to the terminal device 120.

In some example embodiments, the number of BWP fields may depend on the number of BWPs activated for previously-active serving cells. In this case, the terminal device 120 may be aware of the size of the second IE beforehand and detect this IE accordingly if no additional cell is activated. In some other example embodiments, the number of BWPI fields may equal to the number of configured serving cells to ensure the reliability. Accordingly, all these BWP fields may be ordered according to the corresponding CIF sequences of the active, previously-active or configured serving cells.

Since the Pcell is generally in active status as discussed above, the BWP field for Pcell may be included in the second IE to identify the BWP (s) activated for the Pcell. Such a BWP field may be located in any predetermined position within the second IE. For example, this BWP field may be arranged at the beginning of this IE.

At block 215, the network device 110 sends to the terminal device 120 an indication (referred to as a third indication) of a set (referred to as a third set) of scheduled active serving cells from the first set of active serving cells in one of the one or more L1 signaling messages (referred to as a third L1 signaling message) . In some example embodiments, the third L1 signaling message may be the same as the second L1 signaling message. It is also possible that the first, second and third L1 signaling messages are different. The third indication may identify scheduled or non-scheduled status of each active serving cell.

In some example embodiments, the third indication may be sent in a further IE (referred to as a third IE) of the first L1 signaling message. In some implementations, the third IE may comprise a number of resource allocation (RA) fields to indicate resources scheduled (or allocated) to the active serving cells for data transmission and/or reception, for example. For the scheduled active serving cell, the RA fields may explicitly identify the corresponding resource allocation.

Different RA values may be used to identify scheduled or non-scheduled status of the active serving cells. For example, a specific value of the RA field (for example, the valid resource allocation in the RA field) may indicate that the corresponding active serving cell is scheduled for data transmission or reception on the corresponding active BWP. A special value of the RA field indicates that the corresponding active serving cell is just in active status but not scheduled for data transmission or reception.

In some example embodiments, a predefined special RA value may be used to indicate “not scheduled and DL measurement triggered” serving cell. For these serving cells, the terminal device 120 may just perform downlink (DL) measurement or transmit Sounding Reference Signals (SRSs) , that is, no data transmission or reception. In some example embodiments, a further predefined RA value may be used indicated no transmission or reception at all.

The number of RA fields may also depend on the number of the active, previously-active or configured serving cells. Accordingly, the RA fields are ordered according to the CIF sequences of the active, previously active or configured serving cells. The implementations of the number of RA fields are similar to those of the number of BWP fields contained in the second IE as discussed above, and the details thereof will be omitted.

In some example embodiments, one dedicated RA field may be included to identify the scheduled status of the active BWP of the Pcell. This field may be arranged at the beginning of the third IE, or other positions.

In some example embodiments, the first, second and third indications may be sent in the same L1 signaling message, or in different L1 signaling messages. If the three indications are included in one L1 signaling message (for example, one DCI message) , only one round of a L1 signaling procedure is needed to activate and schedule a serving cell as well as its corresponding BWP, thereby allowing fast data transmission and reception and short delay for data transmission. Meanwhile, the DL control overhead may be reduced significantly. At the terminal device 120, the BD may be used for decoding the L1 signaling message since the sizes (or lengths or the numbers of bits) of the first, second and third IEs may be dynamically changed depending on the number of active serving cells.

In the case that the three indications is separated in different L1 signaling messages, for example, in some example embodiments, the first indication may be contained in one of two L1 signaling messages, and the second and third indications may be contained in the other of the two L1 signaling messages. In these embodiments, the first indication may be sent only when necessary, for example, only when the active or de-active status of the serving cells changes. In the example embodiments where the sizes of the second and third IEs are associated with the size of the first IE, the size of the second and third IEs may be implicitly indicated by the size of the first IE.

FIG. 3 illustrates an example process 300 of transmitting two L1 signaling messages to indicate the active or de-active status of the serving cells and the corresponding active BWPs and resources in accordance with some example embodiments of the present disclosure. In this example, the terminal device 120 is configured with two serving cells operating in different component carriers (CCs) , respectively referred to as CC#0 and CC#1. CC#0 is primary, and CC#1 is secondary.

As shown, in a time slot 302 (for example, Slot#0) , a L1 signaling message 304 is transmitted on an active BWP (for example, BWP#0) of CC#0 in Physical Downlink Shared Channel (PDSCH) to indicate that CC#0 is active and CC#1 is not active. A L1 signaling message 306 is also transmitted in the PDSCH to indicate the RA for BWP#0 of CC#0. In a time slot 308 (for example, Slot#1) , a L1 signaling message 310 is sent on BWP#0 of CC#0 to indicate new RA scheduled for BWP#0 of CC#0. In this example, the active status of the serving cells are not changed, and thus the L1 signaling message indicating active status of the serving cells is not transmitted.

In a time slot 312 (for example, Slot#2) , a L1 signaling message 314 is sent on BWP#0 of CC#0 to indicate that both CC#0 and CC#1 are active. On BWP#0 of CC#1, a L1 signaling message 316 is sent to indicate the resources scheduled for BWP#0 of CC#0 and BWP#0 of CC#1. In this example, the RA field corresponding to CC#1 indicates with special predetermined value that only measurement is triggered on BWP#0 of CC#1 but no data are scheduled, as shown.

Subsequently,

L1 signaling messages

318 and 320 are sent on BWP#0 of CC#1 in time slots 322 and 324 (for example, slot#3 and slot#4) to indicate the resources newly scheduled for BWPs of CC#0 and CC#1. As shown, the RA field in the L1 signaling message 318 indicates with special predetermined value of corresponding RA field that BWP#0 of CC#1 is not scheduled.

It is to be understood that the L1 signaling messages for indicating the active status of the serving cell and the corresponding scheduled resource and BWP is shown to be sent in the same time slot only for the purpose of illustration, without suggesting any limitation. In other implementations, the L1 signaling messages may be sent in different time slots.

Based on the above first, second and third indications from the network device 110, the terminal device 120 may identify the active status of each configured serving cell, and ma also identify the active BWP of each active serving cell as well as the scheduled status and resource allocation of the active serving cells. Accordingly, different behaviors and operations will be taken at the terminal device 120 in different situations. For example, for active and scheduled serving cells, the terminal device 120 may conduct data reception or transmission. For active but non-scheduled serving cells, the terminal device 120 may just perform the DL measurement or SRS transmissions. In addition, the terminal device 120 may stop all activities on the non-active serving cell.

FIG. 4 shows a flowchart of an example method 400 in accordance with some example embodiments of the present disclosure. The method 400 can be implemented by the terminal device 120 as shown in FIG. 1. For the purpose of discussion, the method 400 will be described with reference to FIG. 1.

At block 405, the terminal device 120 receives the first indication of the first set of active serving cells in the first L1 signaling message in any of the active serving cells. In the example embodiments where the first indication is sent in the first IE, the terminal device 120 may detect the first IE, and then obtain the first indication from the first IE. Thus, the terminal device 120 may identify the active or de-active status of each configured serving cell.

In the example embodiments where the first indication identifies only the active serving cells, the size of the first IE may be dynamically changed depending on the number of active serving cells. In this case, the terminal device 120 may perform the BD for decoding the L1 signaling message.

In the example embodiments where the first IE has the predetermined size, the terminal device 120 may detect the first IE based on the predetermined size. For example, the terminal device 120 may receive an explicit indication of the predetermined size in higher layer signaling or determine implicitly the predetermined size from other parameter (s) received in higher layer signaling, such as RRC signaling, from the network device 110. As another example, the predetermined size is related to the maximum number of configured serving cells which is specified in the communication network or based on the reported capability by the terminal device 120, and the terminal device 120 is aware of the size in advance.

At block 410, the terminal device 120 receives from the network device 110 the second indication of the second set of active BWPs for the first set of active serving cells in the second L1 signaling message. In the embodiments where the second indication is sent in the second IE, the terminal device 120 may detect the second IE, and then obtain the second indication from the second IE. In this way, for active serving cell, the terminal device 120 may identify which configured BWP may be switched or activated for the following data transmission. Upon reception of the first indication, the terminal device 120 may further check the active BWP for all active serving cell based on the second indication. The final behavior of the terminal device 120 may depend on the third indication.

At block 415, the terminal device 120 receives from the network device 110 the third indication of the third set of scheduled active serving cells in the L1 signaling message. In the example embodiments where the third indication is sent in the third IE, the terminal device 120 may detect the third IE, and then obtain the third indication from the third IE. For an active serving cell, the terminal device 120 may identify whether or not the corresponding active BWP is scheduled for data transmission, for example, based on whether RA field (s) indicates the valid resource allocation, such as at least one scheduled resource block (RB) or physical resource block (PRB) , or not. For a scheduled active serving cell, the terminal device 120 may perform data reception or transmission according to the RA and other scheduling information on the corresponding active BWP.

In the example embodiments where the first, second and third indications are contained in one L1 signaling message, the terminal device 120 may perform the BD for all possible sizes of the L1 signaling message given the dynamically changed number of active serving cells. If the size of the second or third IE is based on previously-active serving cells or the size depends to the number of configured serving cells, the terminal device 120 may be aware of the size and detect the corresponding IE base on the assumed size.

In the example embodiments where the first indication is sent in one of two L1 signaling messages and the second and third indications are sent in the other of the two L1 signaling messages, the size of the second or third IE may depend on the size of the first IE. In this case, no blind decoding is needed for decoding the L1 signaling message containing the second and third indications, thereby further reducing the transmission delay and complexity.

In some example embodiments, for an active and non-scheduled serving cell, the terminal device 120 may further be indicated whether the measurement is triggered or not in the cell. For example, a predefined RA value may indicate such measurement triggering. If the measurement is triggered, the terminal device 120 may just conduct configured DL measurements of configured SRS transmissions on the corresponding active BWP of the non-scheduled active serving cell, for example, for mobility management or channel station information (CSI) feedback. Accordingly, a CSI report may be triggered on a Physical Uplink Control Channel (PUCCH) when the network device 110 has large amount of data to be scheduled. This is benefitial to the coming potential scheduling operation.

All operations and features as described above for the method 200 with reference to FIGS. 2 and 3 are likewise applicable to the method 400 and have similar effects. For the purpose of simplification, the details will be omitted.

In some example embodiments, an apparatus capable of performing the

method

200 or 400 may comprise means for performing the respective steps of the

method

200 or 400. The means may be implemented in any suitable rorm. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus capable of performing the method 200 comprises: means for sending, by a network device to a terminal device, a first indication of a first set of active serving cells from a plurality of serving cells in a first Layer 1 signaling message; means for sending, to the terminal device, a second indication of a second set of active bandwidth parts for the first set of active serving cells in a second Layer 1 signaling message; and means for sending, to the terminal device, a third indication of a third set of scheduled active serving cells from the first set of active serving cells in a third Layer 1 signaling message.

In some example embodiments, the means for sending the first indication may comprise means for sending the first indication in a first information element of the first Layer 1 signaling message.

In some example embodiments, the apparatus may further comprise means for sending, to the terminal device, an indication of a predetermined size of the first information element in a higher layer signaling message.

In some example embodiments, the plurality of serving cells may comprise a primary cell and a set of secondary cells. The first set of active serving cells may comprise at least one active secondary cell in the set of secondary cells.

In some example embodiments, the means for sending the second indication may comprise means for sending the second indication in a second information element of the second Layer 1 signaling message.

In some example embodiments, the second information element may comprise a number of bandwidth part fields for indicating bandwidth parts activated for the first set of active serving cells.

In some example embodiments, the number of bandwidth part fields may be associated to the number of active serving cells in the first set of active serving cells.

In some example embodiments, the means for sending the third indication may comprise means for sending the third indication in a third information element of the third Layer 1 signaling message.

In some example embodiments, the third information element may comprise a number of resource allocation fields for indicating resources scheduled for the first set of active serving cells.

In some example embodiments, the number of resource allocation fields may be associated to the number of active serving cells in the first set of active serving cells.

In some example embodiments, a predefined value of the resource allocation field may indicate downlink measurement to be performed by the terminal device in the active serving cell corresponding to the resource allocation field.

In some example embodiments, the second L1 signaling message may be the same as the third L1 signaling message and different from the first L1 signaling message. In some example embodiments, the first, second and third L1 signaling messages may be the same L1 signaling message.

In some example embodiments, at least one of the first, second and third layer 1 signaling messages may be a downlink control information message.

In some example embodiments, the apparatus capable of performing the method 400 comprises: means for receiving, by a terminal device from a network device, a first indication of a first set of active serving cells from a plurality of serving cells in a first Layer 1 signaling message; means for receiving, from the network device, a second indication of a second set of active bandwidth parts for the first set of active serving cells in a second Layer 1 signaling message; and means for receiving, from the network device, a third indication of a third set of scheduled active serving cells from the first set of active serving cells in a third Layer 1 signaling message.

In some example embodiments, the means for receiving the first indication may comprise: means for detecting a first information element of the first Layer 1 signaling message; and means for obtaining the first indication from the first information element.

In some example embodiments, the apparatus may further comprise means for receiving an indication of a predetermined size of the first information element in a higher layer signaling message.

In some example embodiments, the means for receiving the second indication may comprise: means for detecting a second information element of the second Layer 1 signaling message; and means for obtaining the second indication from the second information element.

In some example embodiments, the means for detecting the second information element may comprise: means for determining a size of the second information element based on the number of active serving cells in the first set of active serving cells; and means for detecting the second information element based on the determined size.

In some example embodiments, the means for receiving the third indication may comprise: means for detecting a third information element of the third Layer 1 signaling message; and means for obtaining the third indication from the third information element.

In some example embodiments, the means for detecting the third information element may comprise: means for determining a size of the third information element based on the number of active serving cells in the first set of active serving cells; and means for detecting the third information element based on the determined size.

In some example embodiments, the apparatus may further comprise means for in response to a predefined value of the resource allocation field, performing measurement in the active serving cell corresponding to the resource allocation field.

FIG. 5 is a simplified block diagram of a device 500 that is suitable for implementing example embodiments of the present disclosure. The device 500 can be implemented at or at least as a part of the network device 110 or the terminal device 120 as shown in FIG. 1.

As shown, the device 500 includes a processor 510, a memory 520 coupled to the processor 510, a communication module 530 coupled to the processor 510, and a communication interface (not shown) coupled to the communication module 530. The memory 520 stores at least a program 540. The communication module 530 is for bidirectional communications. The communication interface may represent any interface that is necessary for communication.

The program 540 is assumed to include program instructions that, when executed by the associated processor 510, enable the device 500 to operate in accordance with example embodiments of the present disclosure, as discussed herein with reference to FIGS. 1-4. The example embodiments herein may be implemented by computer software executable by the processor 510 of the device 500, or by hardware, or by a combination of software and hardware. The processor 510 may be configured to implement various example embodiments of the present disclosure.

The memory 520 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 520 is shown in the device 500, there may be several physically distinct memory modules in the device 500. The processor 510 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 500 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

When the device 500 acts as the network device 110, the memory 520 and the program 540 may work with the processor 510 to cause the device 500 to perform the method 200 as described above with reference to FIGS. 2 and 3. When the device 500 acts as the terminal device 120, the memory 520 and the program 540 may work with the processor 510 cause the device 500 to perform the method 400 as described above with reference to FIG. 4. All operations and features as described above with reference to FIGS. 1-4 are likewise applicable to the device 500 and have similar effects. For the purpose of simplification, the details will be omitted.

Generally, various example embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects 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. While various aspects of example embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method 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 present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the

methods

200 and 400 as described above with reference to FIGS. 1-4. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various example embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable media.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , Digital Versatile Disc (DVD) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular example embodiments. Certain features that are described in the context of separate example embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple example embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Various example embodiments of the techniques have been described. In addition to or as an alternative to the above, the following examples are described. The features described in any of the following examples may be utilized with any of the other examples described herein.

Claims

A device comprising:

at least one processor; and

at least one memory including computer program code;

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

send, by a network device to a terminal device, a first indication of a first set of active serving cells from a plurality of serving cells in a first Layer 1 signaling message;

send, to the terminal device, a second indication of a second set of active bandwidth parts for the first set of active serving cells in a second Layer 1 signaling message; and

send, to the terminal device, a third indication of a third set of scheduled active serving cells from the first set of active serving cells in a third Layer 1 signaling message.
The device of claim 1, wherein the device is caused to send the first indication by:

sending the first indication in a first information element of the first Layer 1 signaling message.
The device of claim 2, wherein the device is further caused to:

send, to the terminal device, an indication of a predetermined size of the first information element in a higher layer signaling message.
The device of any of claims 1-3, wherein the plurality of serving cells comprise a primary cell and a set of secondary cells, and the first set of active serving cells comprises at least one active secondary cell in the set of secondary cells.
The device of any of claims 1-4, wherein the device is caused to send the second indication by:

sending the second indication in a second information element of the second Layer 1 signaling message.
The device of claim 5, wherein the second information element comprises a number of bandwidth part fields for indicating bandwidth parts activated for the first set of active serving cells.
The device of claim 6, wherein the number of bandwidth part fields is associated to the number of active serving cells in the first set of active serving cells.
The device of any of claims 1-7, wherein the device is caused to send the third indication by:

sending the third indication in a third information element of the third Layer 1 signaling message.
The device of claim 8, wherein the third information element comprises a number of resource allocation fields for indicating resources scheduled for the first set of active serving cells.
The device of claim 9, wherein the number of resource allocation fields is associated to the number of active serving cells in the first set of active serving cells.
The device of claim 9 or 10, wherein a predefined value of the resource allocation field indicates measurement to be performed by the terminal device in the active serving cell corresponding to the resource allocation field.
The device of any of claims 1-11, wherein the second Layer 1 signaling message is the same as the third Layer 1 signaling message and different from the first Layer 1 signaling message.
The device of any of claims 1-11, wherein the first, second and third Layer 1 signaling messages are the same Layer 1 signaling message.
The device of any of claims 1-13, wherein at least one of the first, second and third layer 1 signaling messages is a downlink control information message.
A device comprising:

at least one processor; and

at least one memory including computer program code;

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

receive, by a terminal device from a network device, a first indication of a first set of active serving cells from a plurality of serving cells in a first Layer 1 signaling message;

receive, from the network device, a second indication of a second set of active bandwidth parts for the first set of active serving cells in a second Layer 1 signaling message; and

receive, from the network device, a third indication of a third set of scheduled active serving cells from the first set of active serving cells in a third Layer 1 signaling message.
The device of claim 15, wherein the device is caused to receive the first indication by:

detecting a first information element of the first Layer 1 signaling message; and

obtaining the first indication from the first information element.
The device of claim 16, wherein the device is further caused to:

receive an indication of a predetermined size of the first information element in a higher layer signaling message.
The device of any of claims 15-17, wherein the plurality of serving cells comprise a primary cell and a set of secondary cells, and the first set of active serving cells comprises at least one active secondary cell in the set of secondary cells.
The device of any of claims 15-18, wherein the device is caused to receive the second indication by:

detecting a second information element of the second Layer 1 signaling message; and

obtaining the second indication from the second information element.
The device of claim 19, wherein the second information element comprises a number of bandwidth part fields for indicating bandwidth parts activated for the first set of active serving cells.
The device of claim 20, wherein the number of bandwidth part fields is associated to the number of active serving cells in the first set of active serving cells.
The device of claim 21, wherein the device is caused to detect the second information element by:

determining a size of the second information element based on the number of active serving cells in the first set of active serving cells; and

detecting the second information element based on the determined size.
The device of any of claims 15-22, wherein the device is caused to receive the third indication by:

detecting a third information element of the third Layer 1 signaling message; and

obtaining the third indication from the third information element.
The device of claim 23, wherein the third information element comprises a number of resource allocation fields for indicating resources scheduled for the first set of active serving cells.
The device of claim 24, wherein the number of resource allocation fields is associated to the number of active serving cells in the first set of active serving cells.
The device of claim 25, wherein the device is caused to detect the third information element by:

determining a size of the third information element based on the number of active serving cells in the first set of active serving cells; and

detecting the third information element based on the determined size.
The device of any of claims 15-26, wherein the device is further caused to:

in response to a predefined value of the resource allocation field, perform measurement in the active serving cell corresponding to the resource allocation field.
The device of any of claims 15-27, wherein the second Layer 1 signaling message is the same as the third Layer 1 signaling message and different from the first Layer 1 signaling message.
The device of any of claims 15-27, wherein the first, second and third Layer 1 signaling messages are the same Layer 1 signaling message.
The device of any of claims 15-29, wherein at least one of the first, second and third layer 1 signaling messages is a downlink control information message.
A method comprising:

sending, by a network device to a terminal device, a first indication of a first set of active serving cells from a plurality of serving cells in a first Layer 1 signaling message;

sending, to the terminal device, a second indication of a second set of active bandwidth parts for the first set of active serving cells in a second Layer 1 signaling message; and

sending, to the terminal device, a third indication of a third set of scheduled active serving cells from the first set of active serving cells in a third Layer 1 signaling message.
The method of claim 30, wherein sending the first indication comprises:

sending the first indication in a first information element of the first Layer 1 signaling message.
The method of claim 32, further comprising:

sending, to the terminal device, an indication of a predetermined size of the first information element in a higher layer signaling message.
The method of any of claims 31-33, wherein the plurality of serving cells comprise a primary cell and a set of secondary cells, and the first set of active serving cells comprises at least one active secondary cell in the set of secondary cells.
The method of any of claims 31-34, wherein sending the second indication comprises:

sending the second indication in a second information element of the second Layer 1 signaling message.
The method of claim 35, wherein the second information element comprises a number of bandwidth part fields for indicating bandwidth parts activated for the first set of active serving cells.
The method of claim 36, wherein the number of bandwidth part fields is associated to the number of active serving cells in the first set of active serving cells.
The method of any of claims 31-37, wherein sending the third indication comprises:

sending the third indication in a third information element of the third Layer 1 signaling message.
The method of claim 38, wherein the third information element comprises a number of resource allocation fields for indicating resources scheduled for the first set of active serving cells.
The method of claim 39, wherein the number of resource allocation fields is associated to the number of active serving cells in the first set of active serving cells.
The method of claim 39 or 40, wherein a predefined value of the resource allocation field indicates measurement to be performed by the terminal device in the active serving cell corresponding to the resource allocation field.
The method of any of claims 31-41, wherein the second Layer 1 signaling message is the same as the third Layer 1 signaling message and different from the first Layer 1 signaling message.
The method of any of claims 31-41, wherein the first, second and third Layer 1 signaling messages are the same Layer 1 signaling message.
The method of any of claims 31-43, wherein the at least one layer 1 signaling message comprises at least one downlink control information message.
A method comprising:

receiving, by a tenninal device from a network device, a first indication of a first set of active serving cells from a plurality of serving cells in a first Layer 1 signaling message;

receiving, from the network device, a second indication of a second set of active bandwidth parts for the first set of active serving cells in a second Layer 1 signaling message; and

receiving, from the network device, a third indication of a third set of scheduled active serving cells from the first set of active serving cells in a third Layer 1 signaling message.
The method of claim 45, wherein receiving the first indication comprises:

detecting a first information element of the first Layer 1 signaling message; and

obtaining the first indication from the first information element.
The method of claim 46, further comprising:

receiving an indication of a predetermined size of the first information element in a higher layer signaling message.
The method of any of claims 45-47, wherein the plurality of serving cells comprise a primary cell and a set of secondary cells, and the first set of active serving cells comprises at least one active secondary cell in the set of secondary cells.
The method of any of claims 45-48, wherein receiving the second indication comprises:

detecting a second information element of the second Layer 1 signaling message; and

obtaining the second indication from the second information element.
The method of claim 49, wherein the second information element comprises a number of bandwidth part fields for indicating bandwidth parts activated for the first set of active serving cells.
The method of claim 50, wherein the number of bandwidth part fields is associated to the number of active serving cells in the first set of active serving cells.
The method of claim 51, wherein detecting the second information element comprises:

determining a size of the second information element based on the number of active serving cells in the first set of active serving cells; and

detecting the second information element based on the determined size.
The method of any of claims 45-52, wherein receiving the third indication comprises:

detecting a third information element of the third Layer 1 signaling message; and

obtaining the third indication from the third information element.
The method of claim 53, wherein the third information element comprises a number of resource allocation fields for indicating resources scheduled for the first set of active serving cells.
The method of claim 54, wherein the number of resource allocation fields is associated to the number of active serving cells in the first set of active serving cells.
The method of claim 55, wherein detecting the third information element comprises:

determining a size of the third information element based on the number of active serving cells in the first set of active serving cells; and

detecting the third information element based on the determined size.
The method of any of claims 54-56, further comprising:

in response to a predefined value of the resource allocation field, performing measurement in the active serving cell corresponding to the resource allocation field.
The method of any of claims 45-57, wherein the second Layer 1 signaling rnessage is the same as the third Layer 1 signaling message and different from the first Layer 1 signaling message.
The method of any of claims 45-57, wherein the first, second and third Layer 1 signaling messages are the same Layer 1 signaling message.
The method of any of claims 45-59, wherein at least one of the first, second and third layer 1 signaling messages is a downlink control information message.
An apparatus comprising:

means for sending, by a network device to a terminal device, a first indication of a first set of active serving cells from a plurality of serving cells in a first Layer 1 signaling message;

means for sending, to the terminal device, a second indication of a second set of active bandwidth parts for the first set of active serving cells in a second Layer 1 signaling message; and

means for sending, to the terminal device, a third indication of a third set of scheduled active serving cells from the first set of active serving cells in a third Layer 1 signaling message.
An apparatus comprising:

means for receiving, by a terminal device from a network device, a first indication of a first set of active serving cells from a plurality of serving cells in a first Layer 1 signaling message;

means for receiving, from the network device, a second indication of a second set of active bandwidth parts for the first set of active serving cells in a second Layer 1 signaling message; and

means for receiving, from the network device, a third indication of a third set of scheduled active serving cells from the first set of active serving cells in a third Layer 1 signaling message.
A computer readable storage medium comprising program instructions stored thereon, the instructions, when executed by a processor of a device, causing the device to perform the method of any of claims 31-44.
A computer readable storage medium comprising program instructions stored thereon, the instructions, when executed by a processor of a device, causing the device to perform the method of any of claims 45-60.