WO2020168467A1

WO2020168467A1 - Terminal and method for performing a group communication

Info

Publication number: WO2020168467A1
Application number: PCT/CN2019/075478
Authority: WO
Inventors: Jianhua Liu
Original assignee: Guangdong Oppo Mobile Telecommunications Corp., Ltd.
Priority date: 2019-02-19
Filing date: 2019-02-19
Publication date: 2020-08-27
Also published as: CN112368976A; CN112368976B

Abstract

A terminal and a method for performing a group communication are provided. The method for performing the group communication of the terminal includes performing a group communication of a group by communicating with a first terminal using an interface and handing of the interface between the terminal and the first terminal when the group communication of the group terminates the first terminal.

Description

TERMINAL AND METHOD FOR PERFORMING A GROUP COMMUNICATION

BACKGROUND OF DISCLOSURE

1. Field of Disclosure

The present disclosure relates to the field of communication systems, and more particularly, to a terminal and a method for performing a group communication.

2. Description of Related Art

In long term evolution (LTE) and new radio (NR) systems, a public network system, such as, a public land network based on public land mobile network (PLMN) , is usually deployed. However, in some scenarios, such as offices, homes, and factories, in order to be more effective and securely managed, local users or administrators usually lay out a local network. Members in a local network group can communicate in a point-to-point manner or point-to-multipoint communication. Further, the prior art does not support a group communication of the members in the local network group within 5G systems.

Therefore, there is a need for a terminal and a method for performing a group communication.

SUMMARY

An object of the present disclosure is to propose a terminal and a method for performing a group communication capable of providing a good group communication performance and high reliability and providing a solution that how a user data is transmitted within 5G system and corresponding control information and/or procedure.

In a first aspect of the present disclosure, a terminal in a group communication includes a memory, a transceiver, and a processor coupled to the memory and the transceiver. The processor is configured to perform a group communication of a group by communicating with a first terminal using an interface and hand of the interface between the terminal and the first terminal when the group communication of the group terminates the first terminal.

In a second aspect of the present disclosure, a method for performing a group communication of a terminal includes performing a group communication of a group by communicating with a first terminal using an interface and handing of the interface between the terminal and the first terminal when the group communication of the group terminates the first terminal.

In a third aspect of the present disclosure, a non-transitory machine-readable storage medium has stored thereon instructions that, when executed by a computer, cause the computer to perform the above method.

In a fourth aspect of the present disclosure, a terminal device includes a processor and a memory configured to store a computer program. The processor is configured to execute the computer program stored in the memory to perform the above method.

BRIEF DESCRIPTION OF DRAWINGS

In order to more clearly illustrate the embodiments of the present disclosure or related art, the following figures will be described in the embodiments are briefly introduced. It is obvious that the drawings are merely some embodiments of the present disclosure, a person having ordinary skill in this field can obtain other figures according to these figures without paying the premise.

FIG. 1 is a block diagram of a user equipment and a terminal performing a group communication according to an embodiment of the present disclosure.

FIG. 2 is a flowchart illustrating a method for performing a group communication of a terminal according to an embodiment of the present disclosure.

FIG. 3 is a schematic diagram illustrating an access network (AN) release procedure according to an embodiment of the present disclosure.

FIG. 4 is a schematic diagram of exemplary illustration of point-to-multipoint communication user plane topologies according to an embodiment of the present disclosure.

FIG. 5 is a schematic diagram of exemplary illustration of point-to-multipoint communication group protocol data unit (PDU) session according to an embodiment of the present disclosure.

FIG. 6 is a block diagram of a system for wireless communication according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure are described in detail with the technical matters, structural features, achieved objects, and effects with reference to the accompanying drawings as follows. Specifically, the terminologies in the embodiments of the present disclosure are merely for describing the purpose of the certain embodiment, but not to limit the disclosure.

FIG. 1 illustrates that, in some embodiments, a user equipment (UE) 10 and a terminal 20 performing a group communication according to an embodiment of the present disclosure are provided. The UE 10 may include a processor 11, a memory 12, and a transceiver 13. The terminal 20 such as a network node may include a processor 21, a memory 22 and a transceiver 23. The

processor

11 or 21 may be configured to implement proposed functions, procedures and/or methods described in this description. Layers of radio interface protocol may be implemented in the

processor

11 or 21. The

memory

12 or 22 is operatively coupled with the

processor

11 or 21 and stores a variety of information to operate the

processor

11 or 21. The

transceiver

13 or 23 is operatively coupled with the

processor

11 or 21, and the

transceiver

13 or 23 transmits and/or receives a radio signal.

The

processor

11 or 21 may include an application-specific integrated circuit (ASIC) , other chipsets, logic circuit and/or data processing devices. The

memory

12 or 22 may include a read-only memory (ROM) , a random access memory (RAM) , a flash memory, a memory card, a storage medium and/or other storage devices. The

transceiver

13 or 23 may include baseband circuitry to process radio frequency signals. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The modules can be stored in the

memory

12 or 22 and executed by the

processor

11 or 21. The

memory

12 or 22 can be implemented within the

processor

11 or 21 or external to the

processor

11 or 21, in which those can be communicatively coupled to the

processor

11 or 21 via various means are known in the art.

The communication between UEs relates to vehicle-to-everything (V2X) communication including vehicle-to-vehicle (V2V) , vehicle-to-pedestrian (V2P) , and vehicle-to-infrastructure/network (V2I/N) according to a sidelink technology developed under 3rd generation partnership project (3GPP) release 14, 15, and beyond. UEs communicate with each other directly via a sidelink interface such as a PC5 interface. The communication between a UE and a terminal such as a network node is according to 3rd generation partnership project (3GPP) new radio (NR) release 14, 15, and beyond.

Some embodiments of the present disclosure propose a terminal and a method for performing a group communication capable of providing a good group communication performance and high reliability and providing a solution that how a user data is transmitted within 5G system and corresponding control information and/or procedure. Further, uplink (DL) and/or downlink (DL) traffic for a 5G-local area network (LAN) communication is forwarded between user plane functions (UPFs) such as protocol data unit session anchor (PSA) UPFs of different protocol data unit (PDU) sessions via Nx. Nx is for example, an interface based on a shared user plane tunnel connecting PSA UPFs of a single 5G LAN group.

In some embodiments, the processor 21 is configured to perform a group communication of a group by communicating with a first terminal using an interface and hand of the interface between the terminal and the first terminal when the group communication of the group terminates the first terminal.

In some embodiments, the processor 21 is configured to initiate an access network (AN) release. In some embodiments, the processor 21 initiating the AN release further includes if the interface is used and all resources for the group communication of the group terminating the first terminal are released, the processor 21 determines to release the interface. In some embodiments, the processor 21 initiating the AN release further includes that the interface and a related tunnel for the interface are kept along with the group. In some embodiments, when the group is created, the terminal configures the interface and the related tunnel for the interface and selects the first terminal to serve for the group according to group information of the group. In some embodiments, when the group is removed, the interface and the related tunnel for the interface are released. In some embodiments, the terminal is a session management function (SMF) , the first terminal is a user plane function (UPF) , the group communication is a protocol data unit (PDU) session, and the interface is a Nx interface. In some embodiments, the processor 21 initiating the AN release further includes if there is a confirmed (R) AN condition or a (R) AN internal reason, a (R) AN decide to initiate a user equipment (UE) context release in the (R) AN.

In some embodiments, when the (R) AN initiates the UE context release in the (R) AN, the (R) AN sends a UE context release request message to an access and mobility management function (AMF) . In some embodiments, the UE context release request message includes a list of PDU session identities (IDs) , and the list of the PDU session IDs indicates a plurality of PDU sessions served by the (R) AN of a UE. In some embodiments, if the AMF receives the UE context release request message or due to an internal AMF event including a reception of a service request or a registration request to establish a non-access stratum (NAS) signaling connection via a NextGen RAN (NG RAN) , the AMF sends a UE context release command to the (R) AN. In some embodiments, if the AMF receives the service request or the registration request to establish the NAS signaling connection via the NG RAN, after successfully authenticating the UE, the AMF releases an old NAS signaling connection and continues a service request or registration request procedure. In some embodiments, if a (R) AN connection with the UE is not already released, either a) the (R) AN requests the UE to release the (R) AN connection, and the (R) AN deletes a UE's context upon receiving a (R) AN connection release confirmation from the UE, or b) if the UE context release command indicates that the UE has already locally released a radio resource control (RRC) connection, the (R) AN locally releases the RRC connection.

In some embodiments, the (R) AN confirms the UE context release command by returning a UE context release complete message to the AMF, and a signaling connection between the AMF and the (R) AN for the UE is released. In some embodiments, for each group communication in the UE context release complete, the AMF invokes, to a SMF, a request including a PDU session ID, a PDU session deactivation, a cause, an operation type, a user location information, an age of location information, and/or a session management (SM) information. In some embodiments, the SMF initiates, to the UPF, a session modification request indicating a need to remove tunnel information of an AN, a UPF terminating N3 interface, or a UPF terminating Nx interface. In some embodiments, the UPF initiates, to the SMF, a session modification response acknowledging the session modification request from the SMF. In some embodiments, for each group communication in the UE context release complete, the SMF invokes, to the AMF, a response acknowledging the request including the PDU session ID, the PDU session deactivation, the cause, the operation type, the user location information, the age of location information, and/or the session management (SM) information.

In some embodiments, the processor 21 is configured to initiate a PDU session release. In some embodiments, the processor 21 initiating the PDU session release further includes when the group communication terminating the first terminal is released, the first terminal, the interface, and a related tunnel for the interface are kept. In some embodiments, the processor 21 initiating the PDU session release further includes when all group communications of the group terminating the first terminal are released, the first terminal, the interface, and a related tunnel for the interface are kept. In some embodiments, the processor 21 initiating the PDU session release further includes when all group communications of the group are released or the group is removed, the first terminal, the interface, and a related tunnel for the interface are released. In some embodiments, the processor 21 initiating the PDU session release further includes when all group communications of the group terminating the first terminal are released, the first terminal is released and/or the interface and a related tunnel for the interface are released. In some embodiments, the first terminal is a UPF, the group communication is a PDU session, and the interface is a Nx interface. In some embodiments, the processor 21 initiating the PDU session release further includes releasing all resources associated with the PDU session including an internet protocol (IP) address and/or prefixes allocated for an IP-based PDU session and/or a UPF resource used by the PDU session.

FIG. 2 illustrates a method 200 for performing a group communication of a terminal according to an embodiment of the present disclosure. The method 200 includes: at block 202, performing a group communication of a group by communicating with a first terminal using an interface, and at block 204, handing of the interface between the terminal and the first terminal when the group communication of the group terminates the first terminal.

In some embodiments, the method 200 further includes initiating an access network (AN) release. In some embodiments, the method 200 initiating the AN release further includes if the interface is used and all resources for the group communication of the group terminating the first terminal are released, the method 200 determines to release the interface. In some embodiments, the method 200 initiating the AN release further includes that the interface and a related tunnel for the interface are kept along with the group. In some embodiments, when the group is created, the terminal configures the interface and the related tunnel for the interface and selects the first terminal to serve for the group according to group information of the group. In some embodiments, when the group is removed, the interface and the related tunnel for the interface are released. In some embodiments, the terminal is a session management function (SMF) , the first terminal is a user plane function (UPF) , the group communication is a protocol data unit (PDU) session, and the interface is a Nx interface. In some embodiments, the method 200 initiating the AN release further includes if there is a confirmed (R) AN condition or a (R) AN internal reason, a (R) AN decide to initiate a user equipment (UE) context release in the (R) AN.

In some embodiments, the method 200 further includes initiating a PDU session release. In some embodiments, the method 200 initiating the PDU session release further includes when the group communication terminating the first terminal is released, the first terminal, the interface, and a related tunnel for the interface are kept. In some embodiments, the method 200 initiating the PDU session release further includes when all group communications of the group terminating the first terminal are released, the first terminal, the interface, and a related tunnel for the interface are kept. In some embodiments, the method 200 initiating the PDU session release further includes when all group communications of the group are released or the group is removed, the first terminal, the interface, and a related tunnel for the interface are released. In some embodiments, the method 200 initiating the PDU session release further includes when all group communications of the group terminating the first terminal are released, the first terminal is released and/or the interface and a related tunnel for the interface are released. In some embodiments, the first terminal is a UPF, the group communication is a PDU session, and the interface is a Nx interface. In some embodiments, the method 200 initiating the PDU session release further includes releasing all resources associated with the PDU session including an internet protocol (IP) address and/or prefixes allocated for an IP-based PDU session and/or a UPF resource used by the PDU session.

FIG. 3 illustrates that, in some embodiments, an access network (AN) release procedure according to an embodiment of the present disclosure is provided. In some embodiments, AN release procedure is used to release a logical NG-access point (AP) signaling connection and associated N3 user plane connections, and (R) AN RRC signaling and resources. When a NG-AP signaling connection is lost due to (R) AN or AMF failure, an AN release is performed locally by an AMF 330 or a (R) AN 320 as described in the procedure flow below without using or relying on any of the signaling shown between the (R) AN 320 and the AMF 330. The AN release causes all UP connections of a UE 310 to be deactivated.

In some embodiments, an initiation of AN release may be due to: (R) AN-initiated with cause e.g. O&M intervention, unspecified failure, (R) AN (e.g. Radio) link failure, user inactivity, inter-system redirection, request for establishment of a quality of experience (QoS) flow for IP multimedia subsystem (IMS) voice, release due to UE generated signaling connection release, mobility restriction etc., or AMF-initiated with cause e.g. unspecified failure, etc.

In some embodiments, both (R) AN-initiated and AMF-initiated AN release procedures are shown in FIG. 3. For this procedure, impacted SMF 350 and UPF 340 are all under control of public land mobile network (PLMN) serving the UE 310, e.g. in home routed roaming case the SMF 350 and UPF 340 in home public land mobile network (HPLMN) are not involved.

In some embodiments, in

steps

1a and 1b, if there is some confirmed (R) AN conditions (e.g. radio link failure) or for other (R) AN internal reason, the (R) AN 320 may decide to initiate the UE context release in the (R) AN 320. In this case, the (R) AN 320 sends an N2 UE context release request (Cause, list of PDU session ID (s) with active N3 user plane) message to the AMF 330. Cause indicates the reason for the release (e.g. AN link failure, O&M intervention, unspecified failure, etc. ) . The list of PDU session ID (s) indicates the PDU sessions served by the (R) AN 320 of the UE 310. The

steps

1a and 1 b are described in TS 38.413 , clause 8.3.2 "UE Context Release Request (gNB initiated) " .

In some embodiments, in a step 2, the AMF 330 to the (R) AN 320: If the AMF 330 receives an N2 UE context release request message or due to an internal AMF event, including a reception of service request or registration request to establish another NAS signaling connection still via NG-RAN, the AMF 330 sends an N2 UE context release command (Cause) to the (R) AN 320. The Cause indicates either the Cause from the (R) AN 320 in the

steps

1a and 1 b or the Cause due to an AMF event. In case the (R) AN 320 is a NG-RAN, the step 2 is described in detail in TS 38.413, clause 8.3.3 "UE Context Release (AMF initiated) " . In case the (R) AN 320 is an N3IWF, the step 2 is described in clause 4.12. In some embodiments, if the AMF 330 receives a service request or a registration request to establish another NAS signaling connection still via NG-RAN, after successfully authenticating the UE 310, the AMF 330 releases the old NAS signaling connection, and then continues the service request or registration request procedure.

In some embodiments, in a step 3 (conditional) , if the (R) AN connection (e.g. RRC connection or NWu connection) with the UE 310 is not already released (the step 1a) , either: a) the (R) AN 320 requests the UE 310 to release the (R) AN connection. Upon receiving (R) AN connection release confirmation from the UE 310, the (R) AN 320 deletes the UE's context, or b) if the Cause in the N2 UE context release command indicates that the UE 310 has already locally released the RRC connection, the (R) AN 320 locally releases the RRC connection.

In some embodiments, in a step 4, the (R) AN 320 confirms the N2 release by returning an N2 UE context release complete (List of PDU session ID (s) with active N3 user plane, UE radio capability, user location information, age of location information) message to the AMF 330. The list of PDU session ID (s) indicates the PDU sessions served by the (R) AN 320 of the UE 310. The AMF 330 stores always the latest UE radio capability information received from the NG-RAN node. The N2 signaling connection between the AMF 330 and the (R) AN 320 for that UE 310 is released. The (R) AN 320 provides a list of recommended cells /TAs /NG-RAN node identifiers for paging to the AMF 330. In some embodiments, if the PLMN has configured secondary RAT usage reporting, the NG-RAN node may provide RAN usage data report. In some embodiments, the step 4 can be performed promptly after the step 2, i.e. it cannot be delayed, for example, in situations where the UE 310 does not acknowledge the RRC connection release.

In some embodiments, in a step 5 (conditional) , the AMF 330 to the SMF 350: For each of the PDU sessions in the N2 UE context release complete, the AMF 330 invokes Nsmf_PDUSession_UpdateSMContext request (PDU session ID, PDU session deactivation, Cause, operation Type, user location information, age of location information, N2 SM Information (Secondary radio access technology (RAT) usage data) ) . The Cause in the step 5 is the same Cause in the step 2. If the list of PDU session ID (s) with active N3 user plane is included in the step 1b, the steps 5 to 7 are performed before the step 2. The operation type is set to "UP deactivate" to indicate deactivation of user plane resources for the PDU session.

In some embodiments, in a step 6a (conditional) , the SMF 350 to the UPF 340: N4 session modification request (AN or N3 or Nx UPF tunnel information to be removed, buffering on/off) . In some embodiments, in the step 6a, the SMF 350 initiates an N4 session modification procedure indicating the need to remove tunnel information of AN or UPF terminating N3. Buffering on/off indicates whether the UPF 340 can buffer incoming DL PDU or not. In some embodiments, if multiple UPFs are used in the PDU session and the SMF 350 determines to release the UPF terminating N3, the step 6a is performed towards the UPF (e.g. PSA) terminating N9 towards the current N3 UPF. The SMF 350 then releases the N4 session towards the N3 UPF (the N4 release is not shown on the call flow) . In some embodiments, option 1: In 5G-LAN, if Nx interfaces are used and all the resource for the PDU sessions terminating the PSA UPF for the corresponding group are released, the SMF 350 determines to additionally release the PSA UPF terminating Nx. In some embodiments, option 2: The Nx interfaces and the related tunnels are always kept along with the group. That means, when the group is created, the SMF 350 based on the group information configures the Nx interfaces and cor network (CN) tunnels for the interfaces, the SMF 350 based on the group information selects the UPFs serving for the group. When the group is removed, the Nx interface and the tunnels are released. In some embodiments, if the cause of AN release is because of user inactivity, or UE redirection, the SMF 350 can preserve guaranteed bit rate (GBR) QoS flows. Otherwise, the SMF 350 can trigger the PDU session modification procedure for the GBR QoS flows of the UE 310 after the AN release procedure is completed.

In some embodiments, in a step 6b (conditional) , the UPF 340 to the SMF 350: N4 session modification response acknowledging the SMF request. In some embodiments, in a step 7 (conditional) , the SMF 350 to the AMF 330: Nsmf_PDUSession_UpdateSMContext response for the step 5. Upon completion of the procedure, the AMF 330 considers the N2 and N3 as released and enters CM-IDLE state.

In some embodiments, a PDU session release is provided. The PDU session release procedure is used to release all the resources associated with a PDU session, including: The IP address/Prefixes allocated for an IP-based PDU session, this may include the release of multiple prefixes in case of multi-homing (as defined in TS 23.501) , any UPF resource (including N3/N9/termination) that is used by the PDU session. In some embodiments, for 5G-LAN, in an option 1: When the PDU session terminating the PSA UPF is released, the PSA UPF, the terminating Nx interface, and tunnel are kept. In some embodiments, when all the PDU sessions terminating the PSA UPF are released, the PSA UPF, the terminating Nx interface, and tunnel are kept. In some embodiments, when all PDU sessions for the group are released or the group is removed, the related PSA UPF, the Nx interface, and the tunnels are released. Alternately, in some embodiments, in an option 2: When all the PDU sessions terminating the PSA UPF are released, the PSA UPF is released and/or the terminating Nx interface and tunnel are released.

FIGS. 4 and 5 illustrate that, in some embodiments, point-to-multipoint group communication is provided. in some embodiments, in order to support one to many communications in one group, group specific packet data network (PDU) session is introduced. Fifth generation system (5GS) can support a group specific PDU session establishment, release, modify along with the group/group member addition or removal. It is understood that session management function (SMF) node 108 is responsible for group specific PDU session management. Different members in the group can be served by same user plane function (UPF) node such as a UPF1 node 106 or different UPF nodes such as the UPF1 node 106 and a UPF2 node 112. In one group, scenario can be illustrated in FIGS. 4 and 5. UE-T 102 is a transmitter UE while UE-R1 104 and UE-R2 110 are the receiver UEs, in which UE-T 102 and UE-R1 104 are served by same UPF1 node 106, UE-R2 110 are served by UPF2 node 112. Data from UE-T 102 is transmitted within fifth generation system (5GS) and routed by UPF nodes such as UPF1 node 106 and UPF2 node 112.

The group specific PDU session is terminated at the member and the serving UPF. When a group is established by one application function (AF) or one UE, a group specific PDU session is established for each group member who is added into the group with the group creation. The SMF node 108 is enhanced to support the group-based PDU session management function, including group-based PDU session establishment. After the group creation, when a group member is added into the group, the group specific PDU session is established for a new joined member. The SMF node 108 is responsible for establishing a routing tunnel between the UPF node serving the new joined member and the UPF nodes serving the authorized transmitting members.

In some embodiments, this procedure describes the one to many communications PDU session establishment procedure. It is understood that one group is managed by a same SMF. The group creation and group member joining procedure is based on other solution and not mentioned in this solution. This embodiment is an example, and the present disclosure is not limited thereto.

When the group is created, and group member UE-T 102 and UE-R1 104 are added into the group, and UE-T 102 is authorized to send one to many data to the member in the group. UE-T 102 initiates group specific PDU session establishment request, including the request S-NSSAI, group information, etc. In details, the group information could be e.g. group index, group specific data network name (DNN) information, or group specific application server information.

After receiving the request from UE-T 102, SMF node 108 selects the UPF1 node 106 as the serving UPF for the specific group based on the S-NSSAI information and group information. SMF node 108 sends session establishment request to UPF1 node 106, including the allocated core network (CN) tunnel information on N3 interface. UPF1 node 106 acknowledges by sending session establishment response message. SMF node 108 sends PDU session accept to the UE-T 102. In case of PDU session type IPv4 or IPv6 or IPv4v6, the SMF node 108 allocates an IP address/prefix for the PDU Session, and the address/prefix is for the group specific. Alternatively, if the group shares the PDU session with other groups, a group specific address is also allocated to at least one UE of other groups.

When UE-R2 110 is added into the group, UE-R2 110 initiates PDU session establishment request to the SMF node 108, including S-NSSAI information and group information. SMF node 108 selects UPF2 node 112 as the serving UPF for UE-R2 110, and determines to establish a routing tunnel between UPF1 node 106 serving UE-T 102 and the UPF2 node 112. SMF node 108 sends session establishment request to UPF2 node 112, including the allocated CN tunnel information, the CN tunnel information includes the UPF2 address of the tunnel between UPF1 node 106 and UPF2 node 112 and the UPF2 address of N3 tunnel. UPF2 node 112 acknowledges by sending session establishment response message. SMF node 108 establishes routing tunnel between UPF1 node 106 and UPF2 node 112, and provides the UPF2 address of the tunnel between UPF1 node 106 and UPF2 node 112 to UPF1 node 106. Also, SMF node 108 provides the association information of this routing tunnel and PDU session for UE-T 102. SMF node 108 sends PDU session accept to UE-R2 110. In case of PDU session type IPv4 or IPv6 or IPv4v6, the SMF node 108 allocates an IP address/prefix for the PDU session, and the address/prefix is the group specific for UE-R2 110. If there is existing PDU session for another group for UE-R2 110, the existing PDU Session can be re-used for a newly joined group, i.e. multiple groups can share one PDU session for the receiving member in the group.

Further, UE-T 102 sends the group data to the UPF1 node 106, UPF1 node determines the receiving UE-R1 104, UE-R2 110 according to the routing association information provided at block 8 and routes the data to the tunnel corresponding to UE-R1 104 and UE-R2 110 respectively. If PDU session is shared by multiple groups, UPF 1 node 106 determines the receiving UE-R1 104, UE-R2 110 according to the group specific address information to obtain the group information.

FIG. 6 is a block diagram of an example system 700 for wireless communication according to an embodiment of the present disclosure. Embodiments described herein may be implemented into the system using any suitably configured hardware and/or software. FIG. 6 illustrates the system 700 including a radio frequency (RF) circuitry 710, a baseband circuitry 720, an application circuitry 730, a memory/storage 740, a display 750, a camera 760, a sensor 770, and an input/output (I/O) interface 780, coupled with each other at least as illustrated.

The application circuitry 730 may include a circuitry, such as, but not limited to, one or more single-core or multi-core processors. The processors may include any combinations of general-purpose processors and dedicated processors, such as graphics processors and application processors. The processors may be coupled with the memory/storage and configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems running on the system.

The baseband circuitry 720 may include a circuitry, such as, but not limited to, one or more single-core or multi-core processors. The processors may include a baseband processor. The baseband circuitry may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency shifting, etc. In some embodiments, the baseband circuitry may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN) , a wireless local area network (WLAN) , a wireless personal area network (WPAN) . Embodiments in which the baseband circuitry is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

In various embodiments, the baseband circuitry 720 may include circuitry to operate with signals that are not strictly considered as being in a baseband frequency. For example, in some embodiments, baseband circuitry may include circuitry to operate with signals having an intermediate frequency, which is between a baseband frequency and a radio frequency.

The RF circuitry 710 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network.

In various embodiments, the RF circuitry 710 may include circuitry to operate with signals that are not strictly considered as being in a radio frequency. For example, in some embodiments, RF circuitry may include circuitry to operate with signals having an intermediate frequency, which is between a baseband frequency and a radio frequency.

In various embodiments, the transmitter circuitry, control circuitry, or receiver circuitry discussed above with respect to the user equipment, eNB, or gNB may be embodied in whole or in part in one or more of the RF circuitry, the baseband circuitry, and/or the application circuitry. As used herein, “circuitry” may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC) , an electronic circuit, a processor (shared, dedicated, or group) , and/or a memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the electronic device circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules.

In some embodiments, some or all of the constituent components of the baseband circuitry, the application circuitry, and/or the memory/storage may be implemented together on a system on a chip (SOC) .

The memory/storage 740 may be used to load and store data and/or instructions, for example, for system. The memory/storage for one embodiment may include any combination of suitable volatile memory, such as dynamic random access memory (DRAM) ) , and/or non-volatile memory, such as flash memory.

In various embodiments, the I/O interface 780 may include one or more user interfaces designed to enable user interaction with the system and/or peripheral component interfaces designed to enable peripheral component interaction with the system. User interfaces may include, but are not limited to a physical keyboard or keypad, a touchpad, a speaker, a microphone, etc. Peripheral component interfaces may include, but are not limited to, a non-volatile memory port, a universal serial bus (USB) port, an audio jack, and a power supply interface.

In various embodiments, the sensor 770 may include one or more sensing devices to determine environmental conditions and/or location information related to the system. In some embodiments, the sensors may include, but are not limited to, a gyro sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of, or interact with, the baseband circuitry and/or RF circuitry to communicate with components of a positioning network, e.g., a global positioning system (GPS) satellite.

In various embodiments, the display 750 may include a display, such as a liquid crystal display and a touch screen display. In various embodiments, the system 700 may be a mobile computing device such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smartphone, etc. In various embodiments, system may have more or less components, and/or different architectures. Where appropriate, methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-transitory storage medium.

In the embodiment of the present disclosure, a terminal and a method of performing a group communication capable of providing a good group communication performance and high reliability and providing a solution that how a user data is transmitted within 5G system and corresponding control information and/or procedure are provided. The embodiment of the present disclosure is a combination of techniques/processes that can be adopted in 3GPP specification to create an end product.

A person having ordinary skill in the art understands that each of the units, algorithm, and steps described and disclosed in the embodiments of the present disclosure are realized using electronic hardware or combinations of software for computers and electronic hardware. Whether the functions run in hardware or software depends on the condition of application and design requirement for a technical plan.

A person having ordinary skill in the art can use different ways to realize the function for each specific application while such realizations should not go beyond the scope of the present disclosure. It is understood by a person having ordinary skill in the art that he/she can refer to the working processes of the system, device, and unit in the above-mentioned embodiment since the working processes of the above-mentioned system, device, and unit are basically the same. For easy description and simplicity, these working processes will not be detailed.

It is understood that the disclosed system, device, and method in the embodiments of the present disclosure can be realized with other ways. The above-mentioned embodiments are exemplary only. The division of the units is merely based on logical functions while other divisions exist in realization. It is possible that a plurality of units or components are combined or integrated in another system. It is also possible that some characteristics are omitted or skipped. On the other hand, the displayed or discussed mutual coupling, direct coupling, or communicative coupling operate through some ports, devices, or units whether indirectly or communicatively by ways of electrical, mechanical, or other kinds of forms.

The units as separating components for explanation are or are not physically separated. The units for display are or are not physical units, that is, located in one place or distributed on a plurality of network units. Some or all of the units are used according to the purposes of the embodiments. Moreover, each of the functional units in each of the embodiments can be integrated in one processing unit, physically independent, or integrated in one processing unit with two or more than two units.

If the software function unit is realized and used and sold as a product, it can be stored in a readable storage medium in a computer. Based on this understanding, the technical plan proposed by the present disclosure can be essentially or partially realized as the form of a software product. Or, one part of the technical plan beneficial to the conventional technology can be realized as the form of a software product. The software product in the computer is stored in a storage medium, including a plurality of commands for a computational device (such as a personal computer, a server, or a network device) to run all or some of the steps disclosed by the embodiments of the present disclosure. The storage medium includes a USB disk, a mobile hard disk, a read-only memory (ROM) , a random access memory (RAM) , a floppy disk, or other kinds of media capable of storing program codes.

While the present disclosure has been described in connection with what is considered the most practical and preferred embodiments, it is understood that the present disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Claims

A terminal in a group communication system, comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver,

wherein the processor is configured to:

perform a group communication of a group by communicating with a first terminal using an interface; and

hand of the interface between the terminal and the first terminal when the group communication of the group terminates the first terminal.
The terminal of claim 1, wherein the processor is configured to initiate an access network (AN) release.
The terminal of claim 2, wherein the processor initiating the AN release further comprises if the interface is used and all resources for the group communication of the group terminating the first terminal are released, the processor determines to release the interface.
The terminal of claim 2, wherein the processor initiating the AN release further comprises that the interface and a related tunnel for the interface are kept along with the group.
The terminal of claim 4, wherein when the group is created, the terminal configures the interface and the related tunnel for the interface and selects the first terminal to serve for the group according to group information of the group.
The terminal of claim 4 or 5, wherein when the group is removed, the interface and the related tunnel for the interface are released.
The terminal of any one of claims 1 to 6, wherein the terminal is a session management function (SMF) , the first terminal is a user plane function (UPF) , the group communication is a protocol data unit (PDU) session, and the interface is a Nx interface.
The terminal of claim 2, wherein the processor initiating the AN release further comprises if there is a confirmed (R) AN condition or a (R) AN internal reason, a (R) AN decide to initiate a user equipment (UE) context release in the (R) AN.
The terminal of claim 8, wherein when the (R) AN initiates the UE context release in the (R) AN, the (R) AN sends a UE context release request message to an access and mobility management function (AMF) .
The terminal of claim 9, wherein the UE context release request message comprises a list of PDU session identities (IDs) , and the list of the PDU session IDs indicates a plurality of PDU sessions served by the (R) AN of a UE.
The terminal of claim 10, wherein if the AMF receives the UE context release request message or due to an internal AMF event comprising a reception of a service request or a registration request to establish a non-access stratum (NAS) signaling connection via a NextGen RAN (NG RAN) , the AMF sends a UE context release command to the (R) AN.
The terminal of claim 11, wherein if the AMF receives the service request or the registration request to establish the NAS signaling connection via the NG RAN, after successfully authenticating the UE, the AMF releases an old NAS signaling connection and continues a service request or registration request procedure.
The terminal of any one of claims 10 to 12, wherein if a (R) AN connection with the UE is not already released, either:

a) the (R) AN requests the UE to release the (R) AN connection, and the (R) AN deletes a UE's context upon receiving a (R) AN connection release confirmation from the UE, or

b) if the UE context release command indicates that the UE has already locally released a radio resource control (RRC) connection, the (R) AN locally releases the RRC connection.
The terminal of claim 13, wherein the (R) AN confirms the UE context release command by returning a UE context release complete message to the AMF, and a signaling connection between the AMF and the (R) AN for the UE is released.
The terminal of claim 14, wherein for each group communication in the UE context release complete, the AMF invokes, to a SMF, a request comprising a PDU session ID, a PDU session deactivation, a cause, an operation type, a user location information, an age of location information, and/or a session management (SM) information.
The terminal of claim 15, wherein the SMF initiates, to the UPF, a session modification request indicating a need to remove tunnel information of an AN, a UPF terminating N3 interface, or a UPF terminating Nx interface.
The terminal of claim 16, wherein the UPF initiates, to the SMF, a session modification response acknowledging the session modification request from the SMF.
The terminal of claim 15, wherein for each group communication in the UE context release complete, the SMF invokes, to the AMF, a response acknowledging the request comprising the PDU session ID, the PDU session deactivation, the cause, the operation type, the user location information, the age of location information, and/or the session management (SM) information.
The terminal of claim 1, wherein the processor is configured to initiate a PDU session release.
The terminal of claim 19, wherein the processor initiating the PDU session release further comprises when the group communication terminating the first terminal is released, the first terminal, the interface, and a related tunnel for the interface are kept.
The terminal of claim 19, wherein the processor initiating the PDU session release further comprises when all group communications of the group terminating the first terminal are released, the first terminal, the interface, and a related tunnel for the interface are kept.
The terminal of claim 19, wherein the processor initiating the PDU session release further comprises when all group communications of the group are released or the group is removed, the first terminal, the interface, and a related tunnel for the interface are released.
The terminal of claim 19, wherein the processor initiating the PDU session release further comprises when all group communications of the group terminating the first terminal are released, the first terminal is released and/or the interface and a related tunnel for the interface are released.
The terminal of any one of claims 19 to 23, wherein the first terminal is a UPF, the group communication is a PDU session, and the interface is a Nx interface.
The terminal of claim 19, wherein the processor initiating the PDU session release further comprises releasing all resources associated with the PDU session comprising an internet protocol (IP) address and/or prefixes allocated for an IP-based PDU session and/or a UPF resource used by the PDU session.
A method performing a group communication of a terminal, comprising:

performing a group communication of a group by communicating with a first terminal using an interface; and

handing of the interface between the terminal and the first terminal when the group communication of the group terminates the first terminal.
The method of claim 26, further comprising initiating an access network (AN) release.
The method of claim 27, wherein initiating the AN release further comprises if the interface is used and all resources for the group communication of the group terminating the first terminal are released, the method comprising determining to release the interface.
The method of claim 27, wherein initiating the AN release further comprises that the interface and a related tunnel for the interface are kept along with the group.
The method of claim 29, wherein when the group is created, the method configures the interface and the related tunnel for the interface and selects the first terminal to serve for the group according to group information of the group.
The method of claim 29 or 30, wherein when the group is removed, the interface and the related tunnel for the interface are released.
The method of any one of claims 26 to 31, wherein the terminal is a session management function (SMF) , the first terminal is a user plane function (UPF) , the group communication is a protocol data unit (PDU) session, and the interface is a Nx interface.
The method of claim 27, wherein initiating the AN release further comprises if there is a confirmed (R) AN condition or a (R) AN internal reason, a (R) AN decide to initiate a user equipment (UE) context release in the (R) AN.
The method of claim 33, wherein when the (R) AN initiates the UE context release in the (R) AN, the (R) AN sends a UE context release request message to an access and mobility management function (AMF) .
The method of claim 34, wherein the UE context release request message comprises a list of PDU session identities (IDs) , and the list of the PDU session IDs indicates a plurality of PDU sessions served by the (R) AN of a UE.
The method of claim 35, wherein if the AMF receives the UE context release request message or due to an internal AMF event comprising a reception of a service request or a registration request to establish a non-access stratum (NAS) signaling connection via a NextGen RAN (NG RAN) , the AMF sends a UE context release command to the (R) AN.
The method of claim 36, wherein if the AMF receives the service request or the registration request to establish the NAS signaling connection via the NG RAN, after successfully authenticating the UE, the AMF releases an old NAS signaling connection and continues a service request or registration request procedure.
The method of any one of claims 35 to 37, wherein if a (R) AN connection with the UE is not already released, either:

a) the (R) AN requests the UE to release the (R) AN connection, and the (R) AN deletes a UE's context upon receiving a (R) AN connection release confirmation from the UE, or

b) if the UE context release command indicates that the UE has already locally released a radio resource control (RRC) connection, the (R) AN locally releases the RRC connection.
The method of claim 13, wherein the (R) AN confirms the UE context release command by returning a UE context release complete message to the AMF, and a signaling connection between the AMF and the (R) AN for the UE is released.
The method of claim 39, wherein for each group communication in the UE context release complete, the AMF invokes, to a SMF, a request comprising a PDU session ID, a PDU session deactivation, a cause, an operation type, a user location information, an age of location information, and/or a session management (SM) information.
The method of claim 40, wherein the SMF initiates, to the UPF, a session modification request indicating a need to remove tunnel information of an AN, a UPF terminating N3 interface, or a UPF terminating Nx interface.
The method of claim 41, wherein the UPF initiates, to the SMF, a session modification response acknowledging the session modification request from the SMF.
The method of claim 40, wherein for each group communication in the UE context release complete, the SMF invokes, to the AMF, a response acknowledging the request comprising the PDU session ID, the PDU session deactivation, the cause, the operation type, the user location information, the age of location information, and/or the session management (SM) information.
The method of claim 26, further comprising initiating a PDU session release.
The method of claim 44, wherein initiating the PDU session release further comprises when the group communication terminating the first terminal is released, the first terminal, the interface, and a related tunnel for the interface are kept.
The method of claim 44, wherein initiating the PDU session release further comprises when all group communications of the group terminating the first terminal are released, the first terminal, the interface, and a related tunnel for the interface are kept.
The method of claim 44, wherein initiating the PDU session release further comprises when all group communications of the group are released or the group is removed, the first terminal, the interface, and a related tunnel for the interface are released.
The method of claim 44, wherein initiating the PDU session release further comprises when all group communications of the group terminating the first terminal are released, the first terminal is released and/or the interface and a related tunnel for the interface are released.
The method of any one of claims 44 to 48, wherein the first terminal is a UPF, the group communication is a PDU session, and the interface is a Nx interface.
The method of claim 44, wherein initiating the PDU session release further comprises releasing all resources associated with the PDU session comprising an internet protocol (IP) address and/or prefixes allocated for an IP-based PDU session and/or a UPF resource used by the PDU session.
A non-transitory machine-readable storage medium having stored thereon instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 26 to 50.
A terminal device, comprising: a processor and a memory configured to store a computer program, the processor configured to execute the computer program stored in the memory to perform the method of any one of claims 26 to 50.