WO2024060189A1

WO2024060189A1 - New srb design for group rrc message transmission

Info

Publication number: WO2024060189A1
Application number: PCT/CN2022/120811
Authority: WO
Inventors: Fangli Xu; Yuqin Chen; Peng Cheng; Haijing Hu; Shu Guo
Original assignee: Apple Inc.
Priority date: 2022-09-23
Filing date: 2022-09-23
Publication date: 2024-03-28

Abstract

A new SRB design for group RRC message transmission is disclosed. A network device may be configured to provide a configuration of a group signaling radio bearer (SRB) to a group of user equipment (UEs), and transmit, on the group SRB, at least one group radio resource controlling (RRC) message that is dedicated to the group of UEs.

Description

NEW SRB DESIGN FOR GROUP RRC MESSAGE TRANSMISSION

TECHNICAL FIELD

This application relates generally to wireless communication systems, including a new signaling radio bearer (SRB) design for group radio resource controlling (RRC) message transmission.

BACKGROUND

Wireless mobile communication technology uses various standards and protocols to transmit data between a base station and a wireless communication device. Wireless communication system standards and protocols can include, for example, 3rd Generation Partnership Project (3GPP) long term evolution (LTE) (e.g., 4G) , 3GPP new radio (NR) (e.g., 5G) , and IEEE 802.11 standard for wireless local area networks (WLAN) (commonly known to industry groups as

) .

As contemplated by the 3GPP, different wireless communication systems standards and protocols can use various radio access networks (RANs) for communicating between a base station of the RAN (which may also sometimes be referred to generally as a RAN node, a network node, or simply a node) and a wireless communication device known as a user equipment (UE) . 3GPP RANs can include, for example, global system for mobile communications (GSM) , enhanced data rates for GSM evolution (EDGE) RAN (GERAN) , Universal Terrestrial Radio Access Network (UTRAN) , Evolved Universal Terrestrial Radio Access Network (E-UTRAN) , and/or Next-Generation Radio Access Network (NG-RAN) .

Each RAN may use one or more radio access technologies (RATs) to perform communication between the base station and the UE. For example, the GERAN implements GSM and/or EDGE RAT, the UTRAN implements universal mobile telecommunication system (UMTS) RAT or other 3GPP RAT, the E-UTRAN implements LTE RAT (sometimes simply referred to as LTE) , and NG-RAN implements NR RAT (sometimes referred to herein as 5G RAT, 5G NR RAT, or simply NR) . In certain deployments, the E-UTRAN may also implement NR RAT. In certain deployments, NG-RAN may also implement LTE RAT.

A base station used by a RAN may correspond to that RAN. One example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly denoted as evolved Node B, enhanced Node B, eNodeB, or eNB) . One example of an NG-RAN base station is a next generation Node B (also sometimes referred to as a or g Node B or gNB) .

A RAN provides its communication services with external entities through its connection to a core network (CN) . For example, E-UTRAN may utilize an Evolved Packet Core (EPC) , while NG-RAN may utilize a 5G Core Network (5GC) .

Frequency bands for 5G NR may be separated into two or more different frequency ranges. For example, Frequency Range 1 (FR1) may include frequency bands operating in sub-6 GHz frequencies, some of which are bands that may be used by previous standards, and may potentially be extended to cover new spectrum offerings from 410 MHz to 7125 MHz. Frequency Range 2 (FR2) may include frequency bands from 24.25 GHz to 52.6 GHz. Bands in the millimeter wave (mmWave) range of FR2 may have smaller coverage but potentially higher available bandwidth than bands in the FR1. Skilled persons will recognize these frequency ranges, which are provided by way of example, may change from time to time or from region to region.

SUMMARY

One aspect of the disclosure provides a network device, comprising: at least one antenna; at least one radio coupled to the at least one antenna; and a processor coupled to the at least one radio; wherein the processor is configured to: provide a configuration of a group SRB to a group of UEs; and transmit, on the group SRB, at least one group RRC message that is dedicated to the group of UEs.

Another aspect of the disclosure provides a first UE, comprising: at least one antenna; at least one radio coupled to the at least one antenna; and a processor coupled to the at least one radio; wherein the processor is configured to: receive, from a network device, a configuration of a group SRB; and receive, from the network device and on the group SRB, at least one group RRC message that is dedicated to the group of UEs comprising the first UE.

Another aspect of the disclosure provides a method of a network device, comprising: providing a configuration of a group SRB to a group of UEs; and transmitting, on the group SRB, at least one group RRC message that is dedicated to the group of UEs.

Another aspect of the disclosure provides a method of a first UE, comprising: receiving, from a network device, a configuration of a group SRB; and receiving, from the network device and on the group SRB, at least one group RRC message that is dedicated to the group of UEs comprising the first UE.

Another aspect of the disclosure provides a computer-readable medium comprising instructions that when executed by a processor of a network device, cause the processor to perform any method disclosed herein for the network device.

Another aspect of the disclosure provides a computer-readable medium comprising instructions that when executed by a processor of a UE, cause the processor to perform any method disclosed herein for the UE.

Another aspect of the disclosure provides a computer program product comprising programs that when executed by a processor of a network device, cause the processor to perform any method disclosed herein for the network device.

Another aspect of the disclosure provides a computer program product comprising programs that when executed by a processor of a UE, cause the processor to perform any method disclosed herein for the UE.

Another aspect of the disclosure provides an apparatus comprising means for performing any method disclosed herein for a network device.

Another aspect of the disclosure provides an apparatus comprising means for performing any method disclosed herein for a UE.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

FIG. 1 illustrates an example architecture of a wireless communication system, according to embodiments disclosed herein.

FIG. 2 illustrates a system for performing signaling between a wireless device and a network device, according to embodiments disclosed herein.

FIG. 3 illustrates an example process for use of the group SRB, according to embodiments disclosed herein.

FIG. 4 illustrates an example process for use of the group SRB, according to embodiments disclosed herein.

FIG. 5 illustrates an example procedure for configuration of a group SRB, according to embodiments disclosed herein.

FIG. 6A illustrates an exemplary PTP transmission mode, according to embodiments disclosed herein.

FIG. 6B illustrates an exemplary PMP transmission mode, according to embodiments disclosed herein.

FIG. 6C illustrates an exemplary hybrid transmission mode, according to embodiments disclosed herein.

FIG. 7A illustrates an example transmission of one or more RRC response messages, according to some embodiments disclosed herein.

FIG. 7B illustrates an example transmission of one or more RRC response messages, according to some embodiments disclosed herein.

FIG. 7C illustrates an example transmission of one or more RRC response messages, according to some embodiments disclosed herein.

FIG. 8A illustrates an example transmission of one or more RRC response messages, according to some embodiments disclosed herein.

FIG. 8B illustrates an example transmission of one or more RRC response messages, according to some embodiments disclosed herein.

DETAILED DESCRIPTION

Various embodiments are described with regard to a UE. However, reference to a UE is merely provided for illustrative purposes. The example embodiments may be utilized with any electronic component that may establish a connection to a network and is configured with the hardware, software, and/or firmware to exchange information and data with the network. Therefore, the UE as described herein is used to represent any appropriate electronic component.

FIG. 1 illustrates an example architecture of a wireless communication system 100, according to embodiments disclosed herein. The following description is provided for an example wireless communication system 100 that operates in conjunction with the LTE system standards 5G or NR system standards, and/or any future cellular communication standards (such as 6G or subsequent generations of standards) as provided by 3GPP technical specifications.

As shown by FIG. 1, the wireless communication system 100 includes UE 102 and UE 104 (although any number of UEs may be used) . In this example, the UE 102 and the UE 104 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks) , but may also comprise any mobile or non-mobile computing device configured for wireless communication.

The UE 102 and UE 104 may be configured to communicatively couple with a RAN 106. In embodiments, the RAN 106 may be NG-RAN, E-UTRAN, etc. The UE 102 and UE 104 utilize connections (or channels) (shown as connection 108 and connection 110, respectively) with the RAN 106, each of which comprises a physical communications interface. The RAN 106 can include one or more base stations, such as base station 112 and base station 114, that enable the connection 108 and connection 110.

In this example, the connection 108 and connection 110 are air interfaces to enable such communicative coupling, and may be consistent with RAT (s) used by the RAN 106, such as, for example, an LTE and/or NR.

In some embodiments, the UE 102 and UE 104 may also directly exchange communication data via a sidelink interface 116. The UE 104 is shown to be configured to access an access point (shown as AP 118) via connection 120. By way of example, the connection 120 can comprise a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, wherein the AP 118 may comprise a

router. In this example, the AP 118 may be connected to another network (for example, the Internet) without going through a CN 124.

In embodiments, the UE 102 and UE 104 can be configured to communicate using orthogonal frequency division multiplexing (OFDM) communication signals with each other or with the base station 112 and/or the base station 114 over a multicarrier communication channel in accordance with various communication techniques, such as, but not limited to, an orthogonal frequency division multiple access (OFDMA) communication technique (e.g., for downlink communications) or a single carrier frequency division multiple access (SC-FDMA) communication technique (e.g., for uplink and ProSe or sidelink communications) , although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers.

In some embodiments, all or parts of the base station 112 or base station 114 may be implemented as one or more software entities running on server computers as part of a virtual network. In addition, or in other embodiments, the base station 112 or base station 114 may be configured to communicate with one another via interface 122. In embodiments where the wireless communication system 100 is an LTE system (e.g., when the CN 124 is an EPC) , the interface 122 may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs and the like) that connect to an EPC, and/or between two eNBs connecting to the EPC. In embodiments where the wireless communication system 100 is an NR system (e.g., when CN 124 is a 5GC) , the interface 122 may be an Xn interface. The Xn interface is defined between two or more base stations (e.g., two or more gNBs and the like) that connect to 5GC, between a base station 112 (e.g., a gNB) connecting to 5GC and an eNB, and/or between two eNBs connecting to 5GC (e.g., CN 124) .

The RAN 106 is shown to be communicatively coupled to the CN 124. The CN 124 may comprise one or more network elements 126, which are configured to offer various data and telecommunications services to customers/subscribers (e.g., users of UE 102 and UE 104) who are connected to the CN 124 via the RAN 106. The components of the CN 124 may be implemented in one physical device or separate physical devices including components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) .

In embodiments, the CN 124 may be an EPC, and the RAN 106 may be connected with the CN 124 via an S1 interface 128. In embodiments, the S1 interface 128 may be split into two parts, an S1 user plane (S1-U) interface, which carries traffic data between the base station 112 or base station 114 and a serving gateway (S-GW) , and the S1-MME interface, which is a signaling interface between the base station 112 or base station 114 and mobility management entities (MMEs) .

In embodiments, the CN 124 may be a 5GC, and the RAN 106 may be connected with the CN 124 via an NG interface 128. In embodiments, the NG interface 128 may be split into two parts, an NG user plane (NG-U) interface, which carries traffic data between the base station 112 or base station 114 and a user plane function (UPF) , and the S1 control plane (NG-C) interface, which is a signaling interface between the base station 112 or base station 114 and access and mobility management functions (AMFs) .

Generally, an application server 130 may be an element offering applications that use internet protocol (IP) bearer resources with the CN 124 (e.g., packet switched data services) . The application server 130 can also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc. ) for the UE 102 and UE 104 via the CN 124. The application server 130 may communicate with the CN 124 through an IP communications interface 132.

FIG. 2 illustrates a system 200 for performing signaling 234 between a wireless device 202 and a network device 218, according to embodiments disclosed herein. The system 200 may be a portion of a wireless communications system as herein described. The wireless device 202 may be, for example, a UE of a wireless communication system. The network device 218 may be, for example, a base station (e.g., an eNB or a gNB) of a wireless communication system.

The wireless device 202 may include one or more processor (s) 204. The processor (s) 204 may execute instructions such that various operations of the wireless device 202 are performed, as described herein. The processor (s) 204 may include one or more baseband processors implemented using, for example, a central processing unit (CPU) , a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

The wireless device 202 may include a memory 206. The memory 206 may be a non-transitory computer-readable storage medium that stores instructions 208 (which may include, for example, the instructions being executed by the processor (s) 204) . The instructions 208 may also be referred to as program code or a computer program. The memory 206 may also store data used by, and results computed by, the processor (s) 204.

The wireless device 202 may include one or more transceiver (s) 210 that may include radio frequency (RF) transmitter and/or receiver circuitry that use the antenna (s) 212 of the wireless device 202 to facilitate signaling (e.g., the signaling 234) to and/or from the wireless device 202 with other devices (e.g., the network device 218) according to corresponding RATs.

The wireless device 202 may include one or more antenna (s) 212 (e.g., one, two, four, or more) . For embodiments with multiple antenna (s) 212, the wireless device 202 may leverage the spatial diversity of such multiple antenna (s) 212 to send and/or receive multiple different data streams on the same time and frequency resources. This behavior may be referred to as, for example, multiple input multiple output (MIMO) behavior (referring to the multiple antennas used at each of a transmitting device and a receiving device that enable this aspect) . MIMO transmissions by the wireless device 202 may be accomplished according to precoding (or digital beamforming) that is applied at the wireless device 202 that multiplexes the data streams across the antenna (s) 212 according to known or assumed channel characteristics such that each data stream is received with an appropriate signal strength relative to other streams and at a desired location in the spatial domain (e.g., the location of a receiver associated with that data stream) . Certain embodiments may use single user MIMO (SU-MIMO) methods (where the data streams are all directed to a single receiver) and/or multi user MIMO (MU-MIMO) methods (where individual data streams may be directed to individual (different) receivers in different locations in the spatial domain) .

In certain embodiments having multiple antennas, the wireless device 202 may implement analog beamforming techniques, whereby phases of the signals sent by the antenna (s) 212 are relatively adjusted such that the (joint) transmission of the antenna (s) 212 can be directed (this is sometimes referred to as beam steering) .

The wireless device 202 may include one or more interface (s) 214. The interface (s) 214 may be used to provide input to or output from the wireless device 202. For example, a wireless device 202 that is a UE may include interface (s) 214 such as microphones, speakers, a touchscreen, buttons, and the like in order to allow for input and/or output to the UE by a user of the UE. Other interfaces of such a UE may be made up of made up of transmitters, receivers, and other circuitry (e.g., other than the transceiver (s) 210/antenna (s) 212 already described) that allow for communication between the UE and other devices and may operate according to known protocols (e.g.,

and the like) .

The wireless device 202 may include an SRB management module 216. The SRB management module 216 may be implemented via hardware, software, or combinations thereof. For example, the SRB management module 216 may be implemented as a processor, circuit, and/or instructions 208 stored in the memory 206 and executed by the processor (s) 204. In some examples, the SRB management module 216 may be integrated within the processor (s) 204 and/or the transceiver (s) 210. For example, the SRB management module 216 may be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the processor (s) 204 or the transceiver (s) 210.

The SRB management module 216 may be used for various aspects of the present disclosure, for example, aspects of FIG. 4. The SRB management module 216 is configured to perform any of the steps described herein for configuration of the group SRB and/or use of the group SRB on the UE side.

The network device 218 may include one or more processor (s) 220. The processor (s) 220 may execute instructions such that various operations of the network device 218 are performed, as described herein. The processor (s) 204 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

The network device 218 may include a memory 222. The memory 222 may be a non-transitory computer-readable storage medium that stores instructions 224 (which may include, for example, the instructions being executed by the processor (s) 220) . The instructions 224 may also be referred to as program code or a computer program. The memory 222 may also store data used by, and results computed by, the processor (s) 220.

The network device 218 may include one or more transceiver (s) 226 that may include RF transmitter and/or receiver circuitry that use the antenna (s) 228 of the network device 218 to facilitate signaling (e.g., the signaling 234) to and/or from the network device 218 with other devices (e.g., the wireless device 202) according to corresponding RATs.

The network device 218 may include one or more antenna (s) 228 (e.g., one, two, four, or more) . In embodiments having multiple antenna (s) 228, the network device 218 may perform MIMO, digital beamforming, analog beamforming, beam steering, etc., as has been described.

The network device 218 may include one or more interface (s) 230. The interface (s) 230 may be used to provide input to or output from the network device 218. For example, a network device 218 that is a base station may include interface (s) 230 made up of transmitters, receivers, and other circuitry (e.g., other than the transceiver (s) 226/antenna (s) 228 already described) that enables the base station to communicate with other equipment in a core network, and/or that enables the base station to communicate with external networks, computers, databases, and the like for purposes of operations, administration, and maintenance of the base station or other equipment operably connected thereto.

The network device 218 may include a SRB management module 232. The SRB management module 232 may be implemented via hardware, software, or combinations thereof. For example, the SRB management module 232 may be implemented as a processor, circuit, and/or instructions 224 stored in the memory 222 and executed by the processor (s) 220. In some examples, the SRB management module 232 may be integrated within the processor (s) 220 and/or the transceiver (s) 226. For example, the SRB management module 232 may be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the processor (s) 220 or the transceiver (s) 226.

The SRB management module 232 may be used for various aspects of the present disclosure, for example, aspects of FIG. 3. The SRB management module 232 is configured to perform any of the steps described herein for configuration of the group SRB and/or use of the group SRB on the network side.

Embodiments contemplated herein provides a new SRB design for group RRC message transmission in wireless communication systems. The SRB described herein may comprise a group SRB, which may be used to provide RRC message transmissions to a group of UEs with reduced signaling overhead, reduced signaling congestion and/or improved security.

FIG. 3 illustrates an example process 300 for use of the group SRB, according to embodiments disclosed herein. The process 300 may be performed by a network device, or by a module of the network device. The network device may be a base station of a cellular network. In an example, the network device may be implemented as an instance of the network device 218. In this example, the process 300 may be performed by processor (s) 220 of the network device 218.

The process 300 may start with step 302. In this step, the network device may be configured to provide a configuration of a group SRB to a group of UEs. The group of UEs may be a selected subset of all the UEs served by a cell associated with the network device. The selected subset may include a plurality of UEs.

The process 300 may then proceed to step 304. In this step, the network device may be configured to transmit, on the group SRB, at least one group RRC message that is dedicated to the group of UEs. The at least one group RRC message dedicated to the group of UEs may include a group RRC signaling message that is intended for the group of UEs, such as a group RRCReconfiguration message.

Existing SRBs, such as SRB1, SRB2, SRB3 or SRB4, include a first type of SRB (for example, SRB1) that is dedicated to a single UE and a second type of SRB that is commonly used for all the UEs served by the network device. Unlike the existing SRBs, the group SRB disclosed herein may be configured to carry transmissions that are dedicated to a group of UEs, which may be a selected subset of all the UEs served by the cell and contain more than one UE. Such group transmissions may be transmitted between the network device and UEs within the group. Moreover, the group transmissions may be protected with one or more security mechanisms that are specific to the corresponding group of UEs. The group transmissions may not be received or decoded by a UE that is not a member of the group.

According to embodiments disclosed herein, the configuration of the group SRB may be based on UE capability and/or network capability. For example, the network device may be configured to determine, based on UE capability and/or network capability, whether or not to enable the group SRB feature for the network, or for a particular UE. Additionally, the network device may be configured to determine how to configure the group SRB (e.g., contents of the configuration of the group SRB) based on UE capability and/or network capability.

According to embodiments disclosed herein, the configuration of the group SRB may be initially provided to each UE of the group of UEs through a UE-dedicated signaling that is associated with said each UE. In an example, the UE-dedicated signaling may be a SRB1 signaling that is dedicatedly used by a respective UE. Different SRB1 signaling may be used for different UEs.

According to embodiments disclosed herein, the configuration of the group SRB may include one or more rules configured for transmissions on the group SRB. The network and the group of UEs may be configured to follow the one or more rules when performing transmissions on the group SRB.

In some embodiments, the one or more rules configured for transmissions on the group SRB may comprise an indication for a transmission mode associated with the group SRB. The transmission mode may include one or more of the following modes:

· a point-to-point (PTP) transmission mode, in which the network device is configured to transmit the at least one group RRC message to each of the group of UEs in a respective transmission;

· a point-to-multiple-point (PTM) transmission mode, in which the network device is configured to transmit the at least one group RRC message to the group of UEs in a common transmission; or

· a hybrid mode that combines the PTP transmission mode and the PTM transmission mode, in which the processor is configured to transmit the at least one group RRC message to each of a first subset of the group of UEs in the PTP transmission mode and transmit the at least one group RRC message to a second subset of the group of UEs in the PTM transmission mode.

In some embodiments, the one or more rules configured for transmissions on the group SRB may further include at least one of:

· a configuration of a Group Radio Network Temporary Identifier (G-RNTI) associated with the group of UEs;

· a configuration of Physical Downlink Control Channel (PDCCH) , Physical Downlink Shared Channel (PDSCH) , Physical Uplink Control Channel (PUCCH) and/or Physical Uplink Shared Channel (PUSCH) ; and/or

· a discontinuous reception (DRX) pattern to be used by the UEs.

In some embodiments, the one or more rules configured for transmissions on the group SRB may further comprise a predetermined condition for the UE to start reception on the group SRB. As such, the one or more rules may indicate the UE to not start reception until the predetermined condition has been satisfied.

In some embodiments, the one or more rules configured for transmissions on the group SRB may comprise a security configuration associated with the group SRB. The security configuration may be specific to the group of UEs. The security configuration may be used for security protection of one or more messages on the group SRB. In an example, the security configuration may include one or more group security keys for security protection of one or more messages on the group SRB. In another example, the security configuration may include at least one group key index for the group of UEs to derive the one or more group security keys for security protection of one or more messages on the group SRB.

According to embodiments disclosed herein, the network device may be further configured to receive one or more RRC response messages from the group of UEs. Optionally, each of the one or more RRC response messages may carry an RRC transaction identifier of the at least one group RRC message.

In some embodiments, each of the one or more RRC response messages may be received via a UE-dedicated scheduling. For example, each of the one or more RRC response messages may be implemented as one of: a response message delivered via a UE-dedicated transmission on the group SRB; a response message carried in a container of a SRB1 message; or a dedicated SRB1 message.

In other embodiments, the one or more RRC response messages may be received on the group SRB via a UE group scheduling. Optionally, each of the one or more RRC response messages may be received in accordance with an uplink grant that is selected by a respective UE based on a predetermined condition. As a result, a first RRC response message of the one or more RRC response messages may be received from a first UE of the group of UEs according to a first uplink grant while a second RRC response message of the one or more RRC response messages may be received from a second UE of the group of UEs according to a different second uplink grant.

In some embodiments, the one or more RRC response messages may be received only from one or more UEs of the group of UEs that satisfy a predetermined radio quality condition. Other UEs that do not satisfy the predetermined radio quality condition may be configured to not transmit the RRC response messages to the network device.

FIG. 4 illustrates an example process 400 for use of the group SRB, according to embodiments disclosed herein. The process 400 may be performed by a UE device, or by a module of the UE device. The UE device may be a wireless device connected to a cellular network. In an example, the wireless device may be implemented as an instance of the wireless device 202. In this example, the process 400 may be performed by processor (s) 204 of the wireless device 202.

The process 400 may start with step 402. In this step, the UE may be configured to receive, from a network device, a configuration of a group SRB. The group SRB may be configured as dedicated to a group of UEs comprising the UE.

The process 400 may then proceed to step 404. In this step, the UE may be configured to receive, from the network device and on the group SRB, at least one group RRC message that is dedicated to the group of UEs.

According to embodiments disclosed herein, the configuration of the group SRB may be based on UE capability of the UE and/or network capability. For example, the UE may be configured to report its UE capability to the network device. The UE may further receive, from the network device, an indication as to whether the group SRB feature is enabled. If the group SRB feature is enabled, the UE may further receive the configuration of the group SRB (e.g., in step 402) .

According to embodiments disclosed herein, the configuration of the group SRB may be initially provided to the UE through a UE-dedicated signaling that is associated with that UE. For a different UE of the same group, the configuration of the group SRB may be initially provided to the different UE through a UE-dedicated signaling that is associated with that different UE. The UE-dedicated signaling may be implemented as a SRB1 signaling, or any other suitable type of UE-dedicated signaling.

According to embodiments disclosed herein, the configuration of the group SRB may include an indication for a transmission mode associated with the group SRB. The transmission mode may include at least one of the PTP transmission mode, the PTM transmission mode, or a hybrid mode that combines the PTP transmission mode and the PTM transmission mode. In the PTP transmission mode, the UE may be configured to monitor a Cell Radio Network Temporary Identifier (C-RNTI) scheduling for transmissions on the group SRB. In the PTM transmission mode, the UE may be configured to monitor a Group Radio Network Temporary Identifier (G-RNTI) scheduling for transmissions on the group SRB. In the hybrid transmission mode, the UE may be configured to monitor both of the C-RNTI scheduling and the G-RNTI scheduling for transmissions on the group SRB.

In some embodiments, the configuration of the group SRB further comprises at least one of: a configuration of G-RNTI associated with the group of UEs; a configuration of PDCCH, PDSCH, PUCCH and/or PUSCH; or a DRX pattern to be used by the UE.

According to embodiments disclosed herein, the configuration of the group SRB may include a predetermined condition for the UE to start reception on the group SRB. The UE may be configured to not start reception until the predetermined condition has been satisfied.

According to embodiments disclosed herein, the configuration of the group SRB may include a security configuration associated with the group SRB. In an example, the security configuration may include one or more group security keys for security protection of one or more messages on the group SRB. In another example, the security configuration may include at least one group key index for the group of UEs to derive the one or more group security keys for security protection of one or more messages on the group SRB.

According to embodiments disclosed herein, the UE may be further configured to transmit an RRC response message to the network device, in response to receiving the at least one group RRC message. The RRC response message may carry an RRC transaction identifier of the at least one group RRC message.

In some embodiments, the RRC response message may be transmitted via a UE-dedicated scheduling that is associated with the UE. For example, the RRC response message may be implemented as one of: a response message delivered via a UE-dedicated transmission on the group SRB; a response message carried in a container of a SRB1 message; or a dedicated SRB1 message.

In other embodiments, the RRC response message may be transmitted on the group SRB via a UE group scheduling. Optionally, the UE may be configured to select an uplink grant for transmission of the RRC response message based on a predetermined condition. As such, the UE may transmit the RRC response message according to a first uplink grant while a different second UE in the group of UEs may transmit a second RRC response message according to a different second uplink grant.

In some embodiments, the UE may be configured to transmit the RRC response message only if a predetermined radio quality condition is satisfied for the UE.

One or more additional details about the process 300 and the process 400 will be described below.

FIG. 5 illustrates an example procedure 500 for configuration of a group SRB, according to embodiments disclosed herein. The procedure 500 may be performed by a network device (NW) and a group of UEs. The network device may be implemented as an instance of the network device 218. Each of the group of UEs may be implemented as an instance of the wireless device 202.

In the embodiment shown in FIG. 5, the UE group may consist of two UEs, UE1 and UE2. According to embodiments disclosed herein, the group of UEs for which the group SRB will be configured may be a selected subset of all the UEs served by a cell of the network device. The selected subset may be determined in a variety of manners. In some embodiments, UEs with same or similar characteristics may be organized into a same group. For example, multiple UEs that are close to each other (e.g., within a specified area/distance from each other) may be grouped together. In other embodiments, UEs that are likely to be controlled together may be organized into a same group. For example, multiple UEs with a same machine function in a manufacture factory may be grouped together, such that the network device may be able to broadcast a group command to all these UEs. Other criteria to group the UEs may be available, without limitation.

Although the group of UEs in the illustrated embodiment includes only UE1 and UE2, it is readily understood that the group of UEs in other embodiments may include more UEs. Also, although a single group of UEs is illustrated, it is readily understood that the network device may serve one or more additional group of UEs (not shown) .

At step 502, an RRC connection may be established between the network device and each of the group of UEs. Specifically, a first RRC connection may be established between the network device and UE1, and a second RRC connection may be established between the network device and UE2. The first and second RRC connections are established within a same step number (i.e., 502) because they belong to a same type of operation. It is readily understood that these connections are not necessarily established simultaneously. The same is also true for the following steps 504, 506, and 508.

As step 504, the network device may be configured to exchange capability information with each of the group of UEs. For example, the network device may transmit a capability request to UE1 and UE2. In response to the capability request, each of the UE1 and UE2 may report its capability information to the network device.

The capability information may include UE’s capability for support of the group SRB feature. Different UEs may have different support of the group SRB feature. The capability information from a particular UE may indicate whether the particular UE supports the group SRB feature and/or how the particular UE supports the group SRB feature. The UE capability for support of the group SRB feature may be reported in a variety of granularities. In one embodiment, the UE capability may be reported per UE, indicating whether and/or how the UE supports the group SRB feature. In another embodiment, the UE capability may be reported per FR (e.g., FR1 or FR2) , indicating whether and/or how the UE supports the group SRB feature in a specific one of FR1 or FR2. In another embodiment, the UE capability may be reported per band, indicating whether and/or how the UE supports the group SRB feature in a specific band. In another embodiment, the UE capability may be reported per division duplex mode (e.g., time division duplex or frequency division duplex) , indicating whether and/or how the UE supports the group SRB feature in a specific division duplex mode.

According to embodiments disclosed herein, the configuration of the group SRB may be based on UE capability and/or network capability. The UE’s capability may include, but is not limited to, those discussed above. The network capability may include, but is not limited to, whether the network associated with the network device possesses the capability to provide the group SRB and/or whether the network chooses to enable the group SRB feature.

For example, the network device may be configured to determine whether or not to enable the group SRB feature for a particular UE. The determination may be at least based on the UE’s capability and/or the network capability. If the network device determines not to enable the group SRB feature for the particular UE, the UE may be configured to receive, on a conventional signaling (such as SRB1) , a conventional UE-dedicated RRC signaling. If the network device determines to enable the group SRB feature for a group of UEs, the network device may determine and provide configuration of the group SRB to the group of UEs.

In the embodiment shown in FIG. 5, the network device determines to enable the group SRB feature for the group of UE1 and UE2. As such, the network device may be configured to provide a configuration of a group SRB to each of UE1 and UE2 at step 506.

According to some embodiments disclosed herein, the configuration of the group SRB may be initially provided to each of UE1 and UE2 through a UE-dedicated signaling. For example, the network device may be configured to provide the configuration of the group SRB to UE1 through a first signaling and provide the configuration of the group SRB to UE2 through a second signaling. The first signaling may be dedicated to UE1 while the second signal may be dedicated to UE2. In the embodiment shown in FIG. 5, the first signaling may be an RRCReconfiguration message carried on a SRB1 transmission dedicated to UE1 and the second signaling may be an RRCReconfiguration message carried in a SRB1 transmission dedicated to UE2. In other embodiments, other types of UE-dedicated transmission than the SRB1 transmissions may be alternatively used without limitation.

In some embodiments, the one or more rules configured for transmissions on the group SRB may include an indication for a transmission mode associated with the group SRB. The indication may be used to indicate how the network device will transmit on the group SRB, such that the group of UEs may receive on the group SRB in a corresponding receiving mode. Exemplary transmission modes may include but are not limited to a PTP transmission mode, a PTM transmission mode, and a hybrid mode that combines the PTP transmission mode and the PTM transmission mode.

In the PTP transmission mode, the network device may be configured to transmit the at least one group RRC message on the group SRB to each of the group of UEs in a point to point manner. The group RRC message from the network device to separate UEs may rely on separate transmissions. The transmission of the group RRC message from the network device to a particular UE may be scheduled by a respective C-RNTI associated with that particular UE Accordingly, each UE may be configured to monitor a respective C-RNTI scheduling for transmissions on the group SRB.

FIG. 6A illustrates an exemplary PTP transmission mode 600A, according to embodiments disclosed herein. As shown, a first transmission of the group RRC message from the network device to UE1 may be scheduled by C-RNTI-1 and via the group SRB, while a second transmission of the group RRC message from the network device to UE2 may be scheduled by C-RNTI-2 and via the group SRB. C-RNTI-1 may be associated with UE1 and C-RNTI-2 may be associated with UE2. C-RNTI-1 may have a different value than C-RNTI-2. UE1 may be configured to monitor a C-RNTI-1 scheduling for transmissions on the group SRB, while UE2 may be configured to monitor a C-RNTI-2 scheduling for transmissions on the group SRB. The first transmission carrying the group RRC message to UE1 may be different from the second transmission carrying the group RRC message to UE2. For example, the first transmission may be directional to the location of UE1 while the second transmission may be directional to the location of UE2.

In the PTM transmission mode, the network device may be configured to transmit the at least one group RRC message to the group of UEs, which includes a plurality of UEs, in a point-to-multiple-point manner. The transmission of at least one group RRC message from the network device to all the plurality of UEs may be scheduled by a common G-RNTI. The common G-RNTI may be specific to the UE group and is common to all the UEs in that group. The configuration of the common G-RNTI may also be a part of the configuration of the group SRB from the network device to the group of UEs. Therefore, each UE in the group may be configured to monitor a common G-RNTI scheduling for transmissions on the group SRB.

FIG. 6B illustrates an exemplary PMP transmission mode 600B, according to embodiments disclosed herein. As shown, a group RRC message may be transmitted from the network device to both of UE1 to UE2 via the group SRB, which may be scheduled by a G-RNTI associated with the group consisting of UE1 and UE2. The transmission of the group RRC message may be carried in a common transmission to both UE1 and UE2. The G-RNTI associated with the group may be allocated to the group of UEs, for example, via the configuration of the group SRB in step 504. UE1 and UE2 may be configured to monitor the G-RNTI scheduling for transmissions on the group SRB.

In addition, UE1 and UE2 under the PTM transmission mode may follow a common DRX pattern, such that these UEs may be able to stay active in a same time window to receive the common transmission on the group SRB. The common DRX pattern may also be allocated to the group of UEs, for example, via the configuration of the group SRB in step 504.

In hybrid transmission mode, the UE may be configured with both of the PTP transmission mode and the PTM transmission mode, but the network device only delivers the data via one of the PTP transmission mode and the PTM transmission mode at one time. That is, the network device may transmit the group RRC message to a particular UE in a transmission mode that is dynamically selected by the network device between the PTP transmission mode and the PTM transmission mode. As a result, the network device may configure different transmission modes to different UEs in the same group of UEs. For example, the network device may transmit the group RRC message to each of a first subset of the group of UEs in the PTP transmission mode while transmit the group RRC message to a second subset of the group of UEs in the PTM transmission mode. The PTP transmission mode and the PTM transmission mode may be the same as described above.

The transmission mode for each UE may be dynamically selected based on a variety of conditions. In one embodiment, the conditions may include a distribution of the group of UEs. For example, if a first subset of the group of UEs are currently widely scattered in the cell, the network device may determine to transmit the group RRC message to each of the first subset of UEs in the PTP transmission mode, because a common transmission under the PTM transmission mode may not be well received by all the scattered UEs. If a second subset of the group of UEs are located closely to each other, the network device may determine to transmit the group RRC message to the second subset of the group of UEs in the PMP transmission mode, because a common transmission under the PMP transmission mode may be well received by all the closely located UEs. With the distribution of the UEs changing (for example, due to UE mobility) over time, the network device may dynamically change the transmission mode selected for each UE. As for the UEs, each UE in the group of UEs may need to prepare for both the PTP transmission mode and the PTM transmission mode, since the UE may not be aware of a currently selected transmission mode for that UE. Specifically, the UE may monitor both the C-RNTI scheduling (associated with that individual UE) and the G-RNTI scheduling (associated with the UE group) for transmissions on the group SRB. Once received a respective one of the C-RNTI scheduling and the G-RNTI scheduling, the UE may operate under a corresponding mode of the PTP transmission mode and the PTM transmission mode.

FIG. 6C illustrates an exemplary hybrid transmission mode 600C, according to embodiments disclosed herein. As shown, the network device may determine the at least one group RRC message may be transmitted to UE1 in the PTM transmission mode. Accordingly, the transmission of the at least one group RRC message to UE1 may be scheduled by a common G-RNTI. The network device may further determine that the at least one group RRC message may be transmitted to UE2 in the PTP transmission mode. Accordingly, a transmission of the at least one group RRC message to UE2 may be scheduled by C-RNTI-2 and via the group SRB. UE1 may not be able to predict which transmission mode the network device is currently used for UE1, so UE1 needs to monitor both of the C-RNTI scheduling (associated with C-RNTI-1) and the G-RNTI scheduling (associated with the common G-RNTI) for transmissions on the group SRB. Similarly, UE2 needs to monitor both of the C-RNTI scheduling (associated with C-RNTI-2) and the G-RNTI scheduling (associated with the common G-RNTI) for transmissions on the group SRB.

The network device may select a suitable transmission mode from the transmission modes discussed above. The selection may be based on various conditions. The various conditions may include but are not limited to a distribution and/or a radio condition of the group of UEs. For example, if all UEs in the group have a radio condition above a threshold, the network device may select the PMP transmission mode for the group of UEs. If all UEs in the group have a radio condition below the threshold, the network device may select the PTP transmission mode for the group of UEs. If the radio condition significantly varies among the group of UEs, the network device may select the hybrid transmission mode for the group of UEs. The network device may include an indication for the selected transmission mode in the configuration of the group SRB.

Turning back to FIG. 5, if the indication for the transmission mode involves the PMP transmission mode (for example, the PMP transmission mode or the hybrid transmission mode) , the one or more rules configured for transmissions on the group SRB may further comprise one or more additional rules associated with PMP transmissions on the group SRB.

In one embodiment, the one or more additional rules may include a configuration of a G-RNTI. The configured G-RNTI may be common to a corresponding group of UEs. The configured G-RNTI may be used for group scheduling for the group of UEs. Specifically, transmissions on the group SRB may be scheduled by the G-RNTI, such that each UE in the corresponding group of UEs may be configured to monitor a corresponding G-RNIT scheduling for transmissions on the group SRB.

Alternatively, or additionally, the one or more additional rules may include a configuration of PDCCH, PDSCH, PUCCH and/or PUSCH. Each UE in a corresponding group of UEs may perform transmissions/receptions on the configured PDCCH, PDSCH, PUCCH and/or PUSCH.

Alternatively, or additionally, the one or more additional rules may include a DRX pattern to be used by each UE associated with the PTM transmission mode. This allows each UE in the PTM transmission mode to stay in a same DRX pattern, such that these UEs may be able to stay active in a same time window to receive a common transmission on the group SRB.

In some embodiments, the one or more rules configured for transmissions on the group SRB may comprise a predetermined condition for the UE to start reception on the group SRB. The UEs in the group of UEs may be configured to not start reception on the group SRB before the predetermined condition has been satisfied.

The predetermined condition may be configured in many aspects. For example, the predetermined condition may be elapse of a specified time period. In this example, the network device may be configured to start transmissions on the group SRB after the specified time period has elapsed, and the UEs may be configured to start reception after the specified time period has elapsed. The network device and/or the UEs may use a timer to determine if the predetermined condition has been satisfied. Other predetermined conditions may be used in other examples.

In some embodiments, the one or more rules configured for transmissions on the group SRB may further comprise a security configuration associated with the group SRB. The security configuration may be used for security protection of one or more messages on the group SRB. The security configuration may be specific to the group of UEs. Different groups of UEs may be configured with different security configurations.

In one embodiment, the security configuration may include one or more group security keys for security protection of one or more messages on the group SRB. The one or more group security keys may be group-specific. Different groups of UEs may be provided with different group security keys, but UEs in a same group may be configured with same group security keys.

As an example, without limitation, the one or more group security keys may include a first key for integrity of RRC messages (e.g., K _RRCint) and/or a second key for encryptingof RRC messages (e.g., K _RRCenc) . The network device may decide these keys and explicitly transmit them to the group of UEs. The group of UEs may apply any suitable security algorithm based on the received one or more group security keys, for security protection of one or more messages on the group SRB. For example, an integrity check mechanism and/or an encryption/decryption algorithm may be applied to the one or more messages on the group SRB with the one or more group security keys. The suitable security algorithm (for example, the integrity check mechanism and/or the encryption/decryption algorithm) may also be configured via the security configuration.

Although the one or more group security keys are explicitly transmitted from the network device to the group of UEs, there is no security risk for such transmissions of group security keys, because the transmissions are carried in a respective UE-dedicated signaling (such as the SRB1 signaling in step 506) .

In another embodiment, the security configuration may include at least one group key index. The at least one group key index may be used by the group of UEs to derive the one or more group security keys for security protection of one or more messages on the group SRB.

In this embodiment, instead of explicitly transmitting the one or more group security keys to the UEs, the network device is configured to transmit at least one group key index to the group of UEs. The UEs may look up, based on the received group key index, at least one corresponding key in a stored key list. The at least one corresponding key may be a group root key. The key list containing a list of candidate group root keys may be provided in advance to the UEs and stored by the UEs. After finding the at least one corresponding key in the stored key list, the UEs may be configured to derive the one or more group security keys (such as, K _RRCint and/or K _RRCenc) based on the at least one corresponding key. After that, the UEs may be configured to apply any security algorithm based on the derived keys, for security protection of one or more messages on the group SRB. Again, an integrity check mechanism and/or an encryption/decryption algorithm may be applied to the one or more messages on the group SRB with the one or more group security keys.

The at least one group key index provided to each group of UEs may be dedicated to that group. Different groups of UEs may be provided with different group key indexes but UEs in a same group may be configured with same group key index. In an example, the at least one group key index provided to a particular group of UEs may be a group identifier of that particular group, associated with the group identifier, or derived from the group identifier. In another example, the at least one group key index provided to a particular group of UEs may be the G-RNTI assigned for that particular group, associated with the G-RNTI, or derived from the G-RNTI. In other examples, the at least one group key index may be any other index that is dedicated to a corresponding group.

According to some embodiments, the security configuration may be applied to Access Spectrum (AS) security of the group SRB disclosed herein. Additionally, if there is any Non-Access Spectrum (NAS) level message supports the group transmission scheme, the same security configuration may be additionally applied to the NAS group message transmission.

After receiving the configuration of group SRB, at step 508, the group of UEs (UE1 and UE2) may operate according to the configuration of the group SRB. Specifically, the UEs may following the one or more configured rules to perform transmissions on the group SRB.

For example, the network device may transmit, on the group SRB, one or more group RRC messages that are dedicated to the group of UEs. The one or more group RRC messages may be transmitted in a transmission mode as indicated in the configuration of step 504. UE1 and UE2, after receiving the configuration of group SRB, may start monitoring a C-RNTI scheduling, a G-RNTI scheduling, or both of them, in accordance with the transmission mode as indicated in the configuration of the group SRB. Additionally, if a predetermined condition for the UE to start reception on the group SRB has been configured, the UEs may monitor the predetermined condition and start reception on the group SRB only after the predetermined condition has been satisfied. Furthermore, transmissions on the group SRB may be protected in accordance with the security configuration discussed above.

According to embodiments disclosed herein, in response to the group RRC message from the network device, the group of UEs may be configured to transmit one or more RRC response messages to the network device. The one or more RRC response messages may be provided as feedback to the group RRC message. For example, when the group RRC message is a RRCReconfiguration message, the one or more RRC response messages may include one or more RRCReconfigurationComplete messages.

According to some embodiments disclosed herein, each of the one or more RRC response messages may be received via a UE-dedicated scheduling. In some examples, each RRC response message may be a group SRB message that is delivered to the network device via the UE-dedicated scheduling. In other examples, the RRC response message may be carried in a SRB1 message, which is delivered to the network device via the UE-dedicated scheduling.

FIGs. 7A-7C illustrates example transmissions of RRC response messages according to embodiments disclosed herein.

FIG. 7 A illustrates an example transmission 700A of one or more RRC response messages, according to some embodiments disclosed herein. In this embodiment, each RRC response messages is a response message delivered via a UE-dedicated transmission on the group SRB. As such, an RRC response message from a particular UE in the group of UEs may be transmitted on the group SRB, which may be scheduled by a respective C-RNTI associated with the particular UE. As shown in FIG. 7A, in response to receiving the group RRC message on group SRB, UE1 is configured to transmit its RRC response message on the group SRB. This transmission is scheduled by C-RNTI-1 associated with UE1. UE2 is configured to transmit its RRC response message on the group SRB. This transmission is scheduled by C-RNTI-2 associated with UE2.

FIG. 7B illustrates an example transmission 700B of one or more RRC response messages, according to some embodiments disclosed herein. In this embodiment, each RRC response messages is a response message carried in a container of a SRB1 message. As such, an RRC response message from a particular UE in the group of UEs may be transmitted on the container in a respective SRB1 signaling, which may be scheduled by a respective C-RNTI associated with the particular UE. As shown in FIG. 7B, in response to receiving the group RRC message on group SRB, UE1 is configured to transmit its RRC response message via a container of a SRB1 dedicated for UE1, which is scheduled by C-RNTI-1 associated with UE1. UE2 is configured to transmit its RRC response message via a container of a SRB1 dedicated for UE2, which is scheduled by C-RNTI-2 associated with UE2. In some examples, the container used to carry the RRC response message may be ULInformationTransfer of a SRB1 signaling. Other suitable containers may also be alternatively used.

FIG. 7C illustrates an example transmission 700C of one or more RRC response messages, according to some embodiments disclosed herein. In this embodiment, a special SRB1 message may be designed as a dedicated SRB1 message for group feedback purpose. The RRC response message from a particular UE in the group of UEs may be transmitted on the special SRB1, which may be scheduled by a respective C-RNTI that is associated with the particular UE. As shown in FIG. 7C, in response to receiving the group RRC message on group SRB, UE1 may be configured to transmit its RRC response message via a special SRB1 dedicated for UE1, which is scheduled by C-RNTI-1 associated with UE1. UE2 is configured to transmit its RRC response message via a special SRB1 dedicated for UE2, which is scheduled by C-RNTI-2 associated with UE2.

According to embodiments disclosed herein, each of the one or more RRC response messages carries an RRC transaction identifier of the at least group RRC message. For one RRC procedure, the group RRC message (e.g., RRCReconfiguration message) and the RRC response message (e.g., RRCReconfigurationComplete message) may have the same RRC transaction identifier (e.g., RRC-TransactionIdentifier) . This allows the network device to identify a corresponding configuration message (e.g., the RRCReconfiguration message) based on the RRC transaction identifier received in the RRC response message.

According to other embodiments disclosed herein, each of the one or more RRC response messages may be received on the group SRB via a UE group scheduling, instead of a UE-dedicated scheduling. The UE group scheduling may be based on the G-RNTI associated with a corresponding group of UEs. In this embodiment, the network device may allocate, via an uplink grant and by the G-RNTI, uplink resources to the UEs for transmitting the one or more RRC response messages. The uplink grant may be a group grant to all UEs in the group.

According to some embodiments, only one or more UEs of the group of UEs that satisfy a predetermined radio quality condition may be configured to transmit one or more RRC response messages. Other UEs in the group that do not satisfy the predetermined radio quality condition may not transmit RRC response messages to the network device. This reduces the concurrent transmissions of RRC response messages that share uplink resources of a same uplink grant, thereby reducing resource contention associated with the RRC response messages, and/or avoiding signaling congestion at the network device.

The predetermined radio quality condition may be provided between the UEs and the network device. For example, the predetermined radio quality condition may be configured via the configuration of group SRB of step 504.

The predetermined radio quality condition may involve any suitable condition. For example, the predetermined radio quality condition may be satisfied when the radio quality of a UE is below a predetermined threshold. The radio quality may be measured by Reference Signal Received Power (RSRP) or any other suitable measurement related to the UE. With this predetermined radio quality condition, only UEs that have a relatively poor radio quality are required to provide RRC response messages to explicitly acknowledge receipt of the group RRC message. UEs that have a good radio quality may be deemed, by default, as having successfully received the group RRC message. Other predetermined radio quality condition may be alternatively or additionally used without limitation.

FIG. 8A illustrates an example transmission 800A of one or more RRC response messages, according to some embodiments disclosed herein. In this embodiment, in response to receiving the group RRC message on group SRB, each UE may be configured to determine if the predetermined radio quality condition is satisfied for that UE. In the example shown in FIG. 8A, UE1 determines the predetermined radio quality condition is not satisfied. Therefore, UE1 may not transmit an RRC response message to the network device. UE2 determines the predetermined radio quality condition is satisfied. Therefore, UE2 may transmit an RRC response message to the network device. The RRC response message may be carried on the group SRB, which may be scheduled by G-RNTI.

The mechanism of FIG. 8A may also be applicable to embodiments of FIGs. 7A-7C where RRC response messages are transmitted via a UE-dedicated scheduling. When applied with the mechanism of FIG. 8A, UE1 and UE2 of FIGs. 7A-7C may be configured to transmit the RRC response message only if the predetermined radio quality condition is satisfied for that UE.

According to some embodiments disclosed herein, different UEs in the same group of UEs may transmit RRC response messages in accordance with different uplink grants, such that the concurrent transmissions of RRC response messages that share uplink resources of a same uplink grant may be reduced. For example, a first UE in the group of UEs may transmit a first RRC response message in accordance with a first uplink grant, while a different second UE in the same group of UEs may transmit a second RRC response message in accordance with a different second uplink grant. The first uplink grant and the second uplink grant may be both associated with the same group of UEs. For example, the first uplink grant and the second grant may both schedule resources by a G-RNTI that is specific to the group of UEs. The first uplink grant and the second uplink grant may be associated with different uplink resources. For example, the first uplink grant may be associated with a first set of uplink resources, while the second uplink grant may be associated with a second set of uplink resources that are different from the first set of uplink resources.

FIG. 8B illustrates an example transmission 800B of one or more RRC response messages, according to some embodiments disclosed herein. In this embodiment, in response to receiving the group RRC message on group SRB in the downlink, each UE may be configured to select an uplink grant for use with transmission of the RRC response message in the uplink. For example, each UE may select an uplink grant that is received in a special time-slot and/or a special frequency resource. As shown in the example of FIG. 8B, UE1 may be configured to select a first uplink grant that is received in an odd time slot (e.g., time slot 3) instead of a second uplink grant that is received in an even time slot (e.g., time slot 6) . In contrast, UE2 may be configured to select the second uplink grant that is received in an even time slot (e.g., time slot 6) instead of the first uplink grant that is received in an odd time slot (e.g., time slot 3) . As such, the transmission of the RRC response message from UE1 may be on the group SRB in accordance with the first uplink grant, while the transmission of the RRC response message from UE2 may be on the group SRB in accordance with the second uplink grant. In this manner, the RRC response messages from the group of UEs may be carried on separate transmissions. As such, the network device is less likely to be overwhelmed by a large number of concurrent RRC response messages.

UEs in a same group may select a respective uplink grant based on a variety of factors. As discussed above, UE1 and UE2 may be configured to select a respective uplink grant based on whether an uplink grant is received in an even time slot or an odd time slot. In this example, the UE may select a respective uplink grant based on its C-RNTI value. Specifically, a UE with an odd C-RNTI value (such as UE1) may select an uplink grant that is received in an odd time slot, while a UE with an even C-RNTI value (such as UE2) may select an uplink grant that is received in an even time slot, or vise versa. Other factors for the group of UEs to select different uplink grants may be alternatively used in other embodiments.

Embodiments disclosed herein provide a new SRB design for group RRC message transmission in wireless communication systems. The SRB described herein comprises a group SRB that may be used to provide RRC message transmissions to a group of UEs, with reduced signaling overhead, reduced signaling congestion, and/or improved security. The new SRB design for group RRC message transmission may be applicable in various scenarios, especially those with a large number of UEs within a same cell sharing one or more common RRC messages.

At least one applicable scenario includes communication in a Non-Terrestrial Network (NTN) . In the NTN, an airborne vehicle (e.g., a high altitude platform) or a spaceborne vehicle (e.g., a satellite) may be used for communications with the UEs. An NTN cell may cover a very wide geographic area on the ground. For example, a satellite of the NTN cell may serve across multiple countries, thereby serving hundreds of thousands of UEs. In this scenario, the cell is moving together with the satellite but the UEs may stay relatively static to the earth, such that a large number of the UEs on the ground have to perform a handover at a same time due to the satellite change. Also, in the feeder link switching case, the cell served by the satellite will change, such that all the UEs served by the satellite have to perform the handover process due to the cell info change, even though the service link is no change. Considering the large cell size of the NTN, many UEs may be served within a same cell. Depending on constellation assumptions (e.g., propagation delay and satellite speed) and UE density, a potentially very large number of UEs may need to perform handover at a given time, leading to possibly large signaling overhead and service continuity challenges. The group SRB disclosed herein may provide a potential solution to the such challenges of the NTN. Specifically, the group SRB allows the cell to transmit one or more group RRC messages associated with the handover process to a UE group containing the large number of UEs. Conventional UE-dedicated RRC messages may be replaced with such group RRC messages, which require much less signaling overhead. Besides, the one or more group RRC messages are fairly protected with a security configuration specific to the UE group, so the one or more group RRC messages will be secured even if they might be received by other irrelevant devices. Additionally, the RRC response messages from the large number of UEs may be scheduled in a variety of ways to avoid overwhelming the cell. Although the NTN scenario is discussed herein, it is readily understood that the new SRB design for group RRC message transmission may be applicable in other scenarios without limitation.

Embodiments contemplated herein include an apparatus comprising means to perform one or more elements of the method 400. This apparatus may be, for example, an apparatus of a UE (such as a wireless device 202 that is a UE, as described herein) .

Embodiments contemplated herein include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of the method 400. This non-transitory computer-readable media may be, for example, a memory of a UE (such as a memory 206 of a wireless device 202 that is a UE, as described herein) .

Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry to perform one or more elements of the method 400. This apparatus may be, for example, an apparatus of a UE (such as a wireless device 202 that is a UE, as described herein) .

Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of the method 400. This apparatus may be, for example, an apparatus of a UE (such as a wireless device 202 that is a UE, as described herein) .

Embodiments contemplated herein include a signal as described in or related to one or more elements of the method 400.

Embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processor is to cause the processor to carry out one or more elements of the method 400. The processor may be a processor of a UE (such as a processor (s) 204 of a wireless device 202 that is a UE, as described herein) . These instructions may be, for example, located in the processor and/or on a memory of the UE (such as a memory 206 of a wireless device 202 that is a UE, as described herein) .

Embodiments contemplated herein include an apparatus comprising means to perform one or more elements of the method 300. This apparatus may be, for example, an apparatus of a base station (such as a network device 218 that is a base station, as described herein) .

Embodiments contemplated herein include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of the method 300. This non-transitory computer-readable media may be, for example, a memory of a base station (such as a memory 222 of a network device 218 that is a base station, as described herein) .

Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry to perform one or more elements of the method 300. This apparatus may be, for example, an apparatus of a base station (such as a network device 218 that is a base station, as described herein) .

Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of the method 300. This apparatus may be, for example, an apparatus of a base station (such as a network device 218 that is a base station, as described herein) .

Embodiments contemplated herein include a signal as described in or related to one or more elements of the method 300.

Embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processing element is to cause the processing element to carry out one or more elements of the method 300. The processor may be a processor of a base station (such as a processor (s) 220 of a network device 218 that is a base station, as described herein) . These instructions may be, for example, located in the processor and/or on a memory of the UE (such as a memory 222 of a network device 218 that is a base station, as described herein) .

For one or more embodiments, at least one of the components set forth in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and/or methods as set forth herein. For example, a baseband processor as described herein in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth herein. For another example, circuitry associated with a UE, base station, network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth herein.

Any of the above described embodiments may be combined with any other embodiment (or combination of embodiments) , unless explicitly stated otherwise. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

Embodiments and implementations of the systems and methods described herein may include various operations, which may be embodied in machine-executable instructions to be executed by a computer system. A computer system may include one or more general-purpose or special-purpose computers (or other electronic devices) . The computer system may include hardware components that include specific logic for performing the operations or may include a combination of hardware, software, and/or firmware.

It should be recognized that the systems described herein include descriptions of specific embodiments. These embodiments can be combined into single systems, partially combined into other systems, split into multiple systems or divided or combined in other ways. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment can be used in another embodiment. The parameters, attributes, aspects, etc. are merely described in one or more embodiments for clarity, and it is recognized that the parameters, attributes, aspects, etc. can be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless specifically disclaimed herein.

It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

Although the foregoing has been described in some detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and apparatuses described herein. Accordingly, the present embodiments are to be considered illustrative and not restrictive, and the description is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Claims

A network device, comprising:

at least one antenna;

at least one radio coupled to the at least one antenna; and

a processor coupled to the at least one radio;

wherein the processor is configured to:

provide a configuration of a group signaling radio bearer (SRB) to a group of user equipment (UEs) ; and

transmit, on the group SRB, at least one group radio resource controlling (RRC) message that is dedicated to the group of UEs.
The network device of claim 1, wherein the configuration of the group SRB is provided to each UE of the group of UEs through a UE-dedicated signaling that is associated with said each UE.
The network device of claim 1, wherein the configuration of the group SRB is based on UE capability and/or network capability.
The network device of claim 1, wherein the configuration of the group SRB comprises a transmission mode associated with the group SRB, the transmission mode comprising at least one of:

a point-to-point (PTP) transmission mode, in which the processor is configured to transmit the at least one group RRC message to each of the group of UEs in a respective transmission; or

a point-to-multiple-point (PTM) transmission mode, in which the processor is configured to transmit at least one group RRC message to the group of UEs in a common transmission; or

a hybrid transmission mode, in which the processor is configured to transmit at least one group RRC message to each of a first subset of the group of UEs in the PTP transmission mode and transmit at least one group RRC message to a second subset of the group of UEs in the PTM transmission mode.
The network device of claim 4, wherein, for the PTM transmission mode, the configuration of the group SRB further comprises at least one of:

a configuration of G-RNTI associated with the group of UEs;

a configuration of Physical Downlink Control Channel (PDCCH) , Physical Downlink Shared Channel (PDSCH) , Physical Uplink Control Channel (PUCCH) and/or Physical Uplink Shared Channel (PUSCH) ; or

a discontinuous reception (DRX) pattern.
The network device of claim 1, wherein the configuration of the group SRB comprises a predetermined condition for the UE to start reception on the group SRB.
The network device of claim 1, wherein the configuration of the group SRB comprises a security configuration associated with the group SRB.
The network device of claim 7, wherein the security configuration associated with the group SRB comprises at least one of:

one or more group security keys for security protection of one or more messages on the group SRB; or

at least one group key index for the group of UEs to derive the one or more group security keys for security protection of one or more messages on the group SRB.
The network device of claim 1, wherein the processor is further configured to receives one or more RRC response messages from the group of UEs.
The network device of claim 9, wherein each of the one or more RRC response messages is received via a UE-dedicated scheduling.
The network device of claim 10, wherein each of the one or more RRC response messages is one of:

a response message delivered via a UE-dedicated transmission on the group SRB;

a response message carried in a container of a SRB1 message; or

a dedicated SRB1 message.
The network device of claim 9, wherein each of the one or more RRC response messages carries an RRC transaction identifier of the at least one group RRC message.
The network device of claim 9, wherein the one or more RRC response messages are received only from one or more UEs of the group of UEs that satisfy a predetermined radio quality condition.
The network device of claim 9, wherein the one or more RRC response messages are received on the group SRB via a UE group scheduling.
The network device of claim 14, wherein each of the one or more RRC response messages is received in accordance with an uplink grant that is selected by a respective UE based on a predetermined condition.
A first user equipment (UE) , comprising:

at least one antenna;

at least one radio coupled to the at least one antenna; and

a processor coupled to the at least one radio;

wherein the processor is configured to:

receive, from a network device, a configuration of a group signaling radio bearer (SRB) ; and

receive, from the network device and on the group SRB, at least one group radio resource controlling (RRC) message that is dedicated to the group of UEs comprising the first UE.
The first UE of claim 16, wherein the configuration of the group SRB is received through a UE-dedicated signaling that is associated with the first UE.
The first UE of claim 16, wherein the configuration of the group SRB is based on UE capability of the first UE and/or network capability.
The first UE of claim 16, wherein the processor is further configured to operate in accordance with a transmission mode indicated in the configuration of the group SRB, the transmission mode comprising at least one of:

a point-to-point (PTP) transmission mode, in which the processor is configured to monitor a Cell Radio Network Temporary Identifier (C-RNTI) scheduling for transmissions on the group SRB;

a point-to-multiple-point (PTM) transmission mode, in which the processor is configured to monitor a Group Radio Network Temporary Identifier (G-RNTI) scheduling for transmissions on the group SRB; or

a hybrid transmission mode, in which the processor is configured to monitor both of the C-RNTI scheduling and the G-RNTI scheduling for transmissions on the group SRB.
The first UE of claim 19, wherein the configuration of the group SRB further comprises at least one of:

a configuration of G-RNTI associated with the group of UEs;

a configuration of PDCCH, PDSCH, PUCCH and/or PUSCH; or

a DRX pattern to be used by the first UE.
The first UE of claim 16, wherein the processor is further configured to start reception on the group SRB after a predetermined condition has been satisfied.
The first UE of claim 16, wherein the configuration of the group SRB comprises a security configuration associated with the group SRB.
The first UE of claim 22, wherein the security configuration associated with the group SRB comprises at least one of:

one or more group security keys for security protection of one or more messages on the group SRB; or

at least one group key index for the first UE to derive the one or more group security keys for security protection of one or more messages on the group SRB.
The first UE of claim 16, wherein in response to receiving the at least one group RRC message, the processor is further configured to transmit an RRC response message to the network device.
The first UE of claim 24, wherein the RRC response message is transmitted via a UE-dedicated scheduling that is associated with the first UE.
The first UE of claim 25, wherein the RRC response message is one of:

a response message delivered via a UE-dedicated transmission on the group SRB;

a response message carried in a container of a SRB1 message; or

a dedicated SRB1 message.
The first UE of claim 24, wherein the RRC response message carries an RRC transaction identifier of the at least one group RRC message.
The first UE of claim 24, wherein the processor is configured to transmit the RRC response message only if a predetermined radio quality condition is satisfied for the first UE.
The first UE of claim 24, wherein the RRC response message is transmitted on the group SRB via a UE group scheduling.
The first UE of claim 29, wherein the first UE is configured to select, based on a predetermined condition, an uplink grant for transmission of the RRC response message.