WO2024092751A1

WO2024092751A1 - Methods and apparatuses for paging and ptm multicast configuration update for mbs multicast service reception in rrc inactive state

Info

Publication number: WO2024092751A1
Application number: PCT/CN2022/129992
Authority: WO
Inventors: Ahmed MOHAMMED MIKAEIL SALIH
Original assignee: Shenzhen Tcl New Technology Co., Ltd.
Priority date: 2022-11-04
Filing date: 2022-11-04
Publication date: 2024-05-10

Abstract

A method for paging and point to multi-point (PTM) multicast configuration update for multicast/broadcast service (MBS) multicast service reception in radio resource control (RRC) inactive state performed by a communication network system includes categorizing, by a base station, user equipment (UEs) based on UE's preferred reception multicast service preference and/or a knowledge of UE's current RRC states into different groups, paging, by the base station, the UEs in different time slots according to UE categories to allow the UEs to trigger RRC connection resume procedures differently to response to a multicast group paging, and/or providing, by the base station, a PTM configuration update to the UEs in a group based signaling.

Description

METHODS AND APPARATUSES FOR PAGING AND PTM MULTICAST CONFIGURATION UPDATE FOR MBS MULTICAST SERVICE RECEPTION IN RRC INACTIVE STATE

BACKGROUND OF DISCLOSURE

1. Field of the Disclosure

The present disclosure relates to the field of wireless communication systems, and more particularly, to methods and apparatuses for paging and point to multi-point (PTM) multicast configuration update for multicast/broadcast service (MBS) multicast service reception in radio resource control (RRC) inactive state. For example, the present disclosure relates to MBS radio resource configuration for user equipments within a cell.

2. Description of the Related Art

In 3GPP Rel-17 multicast and broadcast service (MBS) , the multicast service reception was specified for UEs in RRC_CONNECTED state only. Later on, it was argued during RAN #94-e Meeting that multicast reception by UEs in RRC connected only may not fully fulfil the requirements of Mission Critical Services (i.e., especially for a scenario of a cell with a large number of UEs) , and may also require keeping UEs always in RRC_CONNECTED state which is not power efficient. Therefore, in RAN#94 meeting a new working item has been agreed targeting RAN enhancement to support multicast reception by UEs in RRC_INACTIVE in Rel-18 MBS. One objective of this working item is to specify the enhancements required to support of multicast reception by UEs in RRC_INACTIVE state including the PTM configuration for UEs receiving multicast in RRC_INACTIVE state.

During RAN2#119-e, two PTM configuration delivery options were agreed for further investigation. The first option is to deliver PTM configuration for UE receiving multicast in inactive state via dedicated RRC signaling and second option is to deliver the PTM configuration to UE via SIB and MCCH similar to release 17 broadcast. For the first option, it was agreed that; if this option is supported for PTM configuration delivery to UE, the multicast group paging mechanism can be used to inform the UE when the network changes the PTM configurations. When adopting such a paging mechanism, there will be an of issue of RACH congestion in Uu radio interface uplink direction due to multiple UE triggering RRC connection resume procedures at the same time to obtain the updated PTM configurations provided within the paging. In addition, there will also be an issue of system load and/or signaling overhead in Uu radio interface downlink direction due to a large number of UEs in the cell (i.e., mission critical UEs) requiring PTM configuration update.

This report provides a method for efficient paging and PTM multicast configuration update for MBS multicast service reception in RRC inactive state which address the issue of the signaling or system load when a large number of UEs in the cell need PTM configuration update.

SUMMARY

An object of the present disclosure is to propose methods and apparatuses for paging and point to multi-point (PTM) multicast configuration update for multicast/broadcast service (MBS) multicast service reception in radio resource control (RRC) inactive state.

In a first aspect of the present disclosure, a method for paging and point to multi-point (PTM) multicast configuration update for multicast/broadcast service (MBS) multicast service reception in radio resource control (RRC) inactive state performed by a communication network system includes categorizing by base station, the user equipment (UEs) the UEs based on their preferred reception multicast service preference and/or the knowledge of current their RRC states into different or groups and defining the appropriate action or mechanisms to alleviate/reduce the congestion in random access channel (RACH) uplink Uu radio interface and/or the signaling load in the downlink Uu radio interface.

In a second aspect of the present disclosure, to reduce the congestion in random access channel (RACH) uplink Uu radio interface, the base station can page UEs within one group can in different time than other UEs in another group so that they can trigger RRC connection resume procedure toward a gNB in different time.

In a third aspect of the present disclosure, to reduce the signaling load in the downlink Uu radio interface which could occur due to transmission of multiple PTM configurations individually to UE in a dedicated manner; the base station may provide the PTM configuration update to a group of UEs via group based signaling, and provide the configuration to other UE group via dedicated signaling.

In a fourth aspect of the present disclosure, a communication network system comprises a memory, a transceiver, and a processor coupled to the memory and the transceiver. The processor is configured to perform the above method.

In a fifth 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 sixth aspect of the present disclosure, a chip includes a processor, configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute the above method.

In a seventh aspect of the present disclosure, a computer readable storage medium, in which a computer program is stored, causes a computer to execute the above method.

In an eighth aspect of the present disclosure, a computer program product includes a computer program, and the computer program causes a computer to execute the above method.

In a ninth aspect of the present disclosure, a computer program causes a computer to execute the above method.

BRIEF DESCRIPTION OF DRAWINGS

In order to illustrate the embodiments of the present disclosure or related art more clearly, 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 an example of signaling congestion type during multicast PTM configuration update including (A) uplink RACH Uu interface congestion in response to the group paging and (B) downlink Uu interface load or congestion due to multiple PTM update transmission in downlink, according to an embodiment of the present disclosure.

FIG. 2 is a diagram of the method for efficient paging and PTM configuration update for multicast reception in RRC inactive state according to an embodiment of the present disclosure.

FIG. 3 is an example of handling of (A) Uu interface uplink RACH congestion due multiple responding to a group paging and (B) Uu interface downlink load or congestion due to multiple PTM update transmission in downlink according to an embodiment of the present disclosure.

FIG. 4 is an example of handling of uplink RACH congestion due to multiple UE resuming the connection in response to multicast paging according to an embodiment of the present disclosure.

FIG. 5A is an example of paging groups UE category and in a different paging occasion within a paging frame according to an embodiment of the present disclosure.

FIG. 5B is an example of paging groups UE category and in a different paging frame according to an embodiment of the present disclosure.

FIG. 6 is an example of handling Uu downlink congestion due to transmitting of PTM configuration to multiple UE simultaneously according to an embodiment of the present disclosure.

FIG. 7 is a block diagram of a system for wireless communication according to an embodiment of the present disclosure.

FIG. 8 is a block diagram of one or more user equipments (UEs) , an RAN node, and a network node of communication in a communication network system according to an embodiment of the present disclosure.

FIG. 9 is a flowchart illustrating a method for paging and point to multi-point (PTM) multicast configuration update for multicast/broadcast service (MBS) multicast service reception in radio resource control (RRC) inactive state performed by a communication network system 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.

In 3GPP Rel-17 multicast and broadcast service (MBS) , the multicast service reception was specified for UEs in RRC_CONNECTED state only. Later on, it was argued during Rel-18 MBS related discussion that multicast reception by UEs in RRC connected only may not fully fulfil the requirements of, e.g., Mission Critical Services and may also require keeping UEs always in RRC_CONNECTED state is not power efficient. Therefore, in 3gpp RAN#94 meeting a new working item has been agreed targeting RAN enhancement to support multicast reception by UEs in RRC_INACTIVE in Rel-18 MBS. One objective of this working item is to specify the enhancements required to support of multicast reception by UEs in RRC_INACTIVE state including the PTM configuration for UEs receiving multicast in RRC_INACTIVE state. During RAN2#119-e, two PTM configuration delivery options were agreed for further investigation. The first option is to deliver PTM configuration for UE receiving multicast in inactive state via dedicated RRC signaling and second option is to deliver the PTM configuration to UE via system information block (SIB) and MBS control channel (MCCH) similar to release 17 broadcast. For the first option, it was agreed if this supported for PTM configuration delivery to UE, the multicast group paging mechanism can be used/adopted to inform the UE when network changes the PTM configurations. When adopting such a mechanism, there will be an of issue of RACH congestion in Uu radio interface uplink direction due to multiple UE triggering RRC connection resume procedures at the same time to obtain the updated PTM configurations provided within the paging as illustrated in FIG. (1A) . In addition, there will also be an issue of system load and/or signaling overhead in Uu radio interface downlink direction due to a large number of UEs in the cell (i.e., mission critical UEs) requiring PTM configuration update as illustrated in FIG. 1 (B) .

This disclosure provides a method for efficient paging and PTM multicast configuration update for MBS multicast service reception in RRC inactive state to address these two issues. The method relies on categorizing by a base station (e.g.., gNB) the UEs based on their preferred reception multicast service preference (i.e., connected or inactive) and/or the knowledge of current their RRC states (i.e., connected or inactive) into different groups. Then, in order to paging a base station the UEs in different time slot according to UE categories to allow them trigger RRC connection resume procedure differently and reduce the RACH congestion in uplink Uu radio interface which could occur if multiple UE were allowed to trigger RRC connection resume procedure simultaneously to response to the multicast group paging, and/or providing by a base station a PTM configuration update to UEs in a group based signaling instead of dedicated one so as so as to reduce system load or Uu radio interface downlink signaling overhead which could resulted if multiple PTM configurations are to be transmitted separately to each individual UE in a dedicated manner. The detail of the method is provided in the following embodiments.

The major advantages of the new method provided in this disclosure may include: 1. The new method could help reducing system load or Uu radio interface downlink signaling overheads the result of frequent transmission UEs paging or PTM configuration separately in a dedicated manner over the air interface and/or help to save some downlink Uu radio interface resource. 2. The new method could help reducing the RACH congestion in uplink Uu radio interface which could occur due to multiple UE triggering RRC connection resume procedure in response to the multicast group paging for obtaining PTM configurations update. 3. The new method allows to have some UEs receiving in RRC connected state while other UEs receiving in RRC inactive state within a cell as per SA requirements.

The detailed description of the method is provided in following embodiments.

This disclosure provides a method for efficient paging and PTM multicast configuration update for MBS multicast service reception in RRC inactive state to address these two issues. The method relies on categorizing by a base station (e.g.., gNB) the UEs based on their preferred reception multicast service preference (i.e., connected or inactive) and/or the knowledge of current their RRC states (i.e., connected or inactive) into different groups . Then, paging a base station the UEs in different time slot according to UE categories to allow them trigger RRC connection resume procedure differently and reduce the RACH congestion in uplink Uu radio interface which could occur if multiple UE were allowed to trigger RRC connection resume procedure simultaneously to response to the multicast group paging, and/or providing by a base station a PTM configuration update to UEs in a group based signaling instead of dedicated one so as so as to reduce system load or Uu radio interface downlink signaling overhead or congestion which could resulted if multiple PTM configurations are to be transmitted separately to each individual UE in a dedicated manner.

In this method (FIG. 2) , upon the reception of multicast service announcement or activation from the network (e.g., NR core network) , the UE may indicate to the network (e.g., via a service request or a session join procedure in a non-access stratum (NAS) signaling it preferred multicast service RRC reception mode (i.e., RRC connected or RRC inactive) . The core network or the UE may provide the UE preferred reception multicast service RRC state and/or the QoS related information (e.g., via NG-C-NG-U or N2/N3 signaling) or the UE may provide it preferred multicast service reception RRC state (e.g., via RRC signaling) to the RAN node or the base station. The base station may categorize the UEs based on the preferred multicast service reception state and/or the knowledge of current their RRC states into different or groups and defining an appropriate action or mechanisms to reduce the uplink/downlink congestion based on UEs preferred RRC reception state, the concurrent UEs RRC state and/or the congestion type as given in Table 1.

In one example, to reduce the congestion in random access channel (RACH) uplink Uu radio interface, the base station can page UEs within one group can in different time slot than other UEs in another group so that differs UEs may trigger RRC connection resume procedure toward a gNB in different time (FIG. 3) (as detailed in the following embodiments) .

In another example, to reduce the signaling load in the downlink Uu radio interface which could occur due to transmission of multiple PTM configurations individually to UE in a dedicated manner; the base station may provide the PTM configuration update to a group of UEs via group based signaling, and provide the configuration to other UE group via dedicated signaling (as detailed in the following embodiments) .

In the above method, the base station may categorize the UEs into:

Group 1: UEs in inactive state prefer multicast reception in inactive state.

Group 2: UEs in inactive state prefer multicast reception in connected state.

Group 3 UEs in connected state prefer multicast reception in inactive state.

Group 4: UEs in connected state prefer multicast reception in connected state.

In the above method, PTM configuration comprises a MAC entity configuration, a set of logical channels with associated RLC entities configurations and PHY channel configurations for MBS radio bearer (MRB) of the multicast session which UE has joined for multicast service reception in inactive or connected mode.

In the above method, group based signaling comprises, a PTM configuration carried within MBS control channel (MCCH) channel and the configuration update is addressed via DCI within the MCCH while the scheduling of MCCH channel is provided via a specific system information block (SIB)

In the above method, the dedicated RRC signaling comprises a PTM configuration carried within an RRC signaling message such as RRC reconfiguration message.

Table 1: An Example of categorizing UEs based on their preferred multicast service reception indication and the knowledge of their concurrent RRC state by the gNB

Embodiment: RACH congestion in uplink due to multiple triggers RRC connection resume on responsd to PTM update paging

In the above method, to reduce the RACH congestion in uplink Uu radio interface which could occur due to multiple UE triggering RRC connection resume procedure in response to the multicast group paging, the base station may the base station may page UEs based on UEs group category in different time slot so that it can receive the RRC resume connection from these UEs in different time and therefore the congestion on RACH can be alleviated in time domain (FIG. 4) . The configuration of the time slot for paging in different group category can be according to the following options.

Option 1: Paging Group 1 UE category (i.e., the UEs in inactive state and prefer multicast reception in inactive} in a different paging occasion other than the paging occasion where the Group 2 UE category (i.e., the UEs in inactive and prefer multicast reception in connected) are paged as illustrated in FIG. 5 (A) .

Option 2: Paging Group 1 UE category (i.e., the UEs in inactive state and prefer multicast reception in inactive} in a different paging frame other than the paging frame where the Group 2 UE category (i.e., the UEs in inactive and prefer multicast reception in connected) are paged as illustrated in FIG. 5 (B) . For this option, Base station is aware about, it may use such QoS requirement of the UEs (which is normally provided by the CN for MBS) when categorizing the UEs or paging them, i.e., it may always page the UEs requiring higher QoS in term of latency or the UE who preferring to move to connected mode for multicast reception in an earlier paging frame than other UEs who not requiring higher QoS or the UE preferring to stay in inactive mode for multicast service reception.

In the above method, to reduce system load in downlink when providing the PTM configurations to a large number of UEs in the cell, the gNB may provide PTM configuration update to a UE group via dedicated signaling and to other UE group via group based signaling as given in FIG. 6.

FIG. 7 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. 7 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 combination of general purpose processors and dedicated processors, such as graphics processors, 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.

FIG. 8 illustrates that, in some embodiments, one or more UEs 10, an RAN node (e.g., gNB) 20, and a network node (e.g., core network (CN) ) 30 for communication in a communication network system 40 according to an embodiment of the present disclosure are provided. The communication network system 40 includes the one or more UEs 10, the RAN node (e.g., gNB) 20, and the network node (e.g., CN) 30. The one or more UEs 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12 and the transceiver 13. The RAN node (e.g., gNB) 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22 and the transceiver 23. The network node (e.g., CN) 30 may include a memory 32, a transceiver 33, and a processor 31 coupled to the memory 32 and the transceiver 33. The

processor

11, 21, or 31 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, 21, or 31. The

memory

12, 22, or 32 is operatively coupled with the

processor

11, 21, or 31 and stores a variety of information to operate the

processor

11, 21, or 31. The

transceiver

13, 23, or 33 is operatively coupled with the

processor

11, 21, or 31, and the

transceiver

13, 23, or 33 transmits and/or receives a radio signal.

The

processor

11, 21, or 31 may include application specific integrated circuit (ASIC) , other chipset, logic circuit and/or data processing device. The

memory

12, 22, or 32 may include read only memory (ROM) , random access memory (RAM) , flash memory, memory card, storage medium and/or other storage device. The

transceiver

13, 23, or 33 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, 22, or 32 and executed by the

processor

11, 21, or 31. The

memory

12, 22, or 32 can be implemented within the

processor

11, 21, or 31 or external to the

processor

11, 21, or 31 in which case those can be communicatively coupled to the

processor

11, 21, or 31 via various means as is known in the art. In some embodiments, the communication network system 40 is configured to perform the followings: categorizing, by a base station, user equipment (UEs) based on UE’s preferred reception multicast service preference and/or a knowledge of UE’s current RRC states into different groups, paging, by the base station, the UEs in different time slots according to UE categories to allow the UEs to trigger RRC connection resume procedures differently to response to a multicast group paging, and/or providing, by the base station, a PTM configuration update to the UEs in a group based signaling.

FIG. 9 is a flowchart illustrating a method for paging and point to multi-point (PTM) multicast configuration update for multicast/broadcast service (MBS) multicast service reception in radio resource control (RRC) inactive state performed by a communication network system according to an embodiment of the present disclosure. FIG. 9 illustrates that in some embodiments, a method for paging and point to multi-point (PTM) multicast configuration update for multicast/broadcast service (MBS) multicast service reception in radio resource control (RRC) inactive state performed by a communication network system includes categorizing by base station, the user equipment (UEs) the UEs based on their preferred reception multicast service preference and/or the knowledge of current their RRC states into different or groups and defining the appropriate action or mechanisms to alleviate/reduce the congestion in random access channel (RACH) uplink Uu radio interface and/or the signaling load in the downlink Uu radio interface. In some embodiments, to reduce the congestion in random access channel (RACH) uplink Uu radio interface, the base station paging UEs within one group in different time than other UEs in another group so that they trigger RRC connection resume procedure toward a gNB in different time. In some embodiments, to reduce the signaling load in the downlink Uu radio interface which occurs due to transmission of multiple PTM configurations individually to a UE in a dedicated manner; a base station providing the PTM configuration update to a group of UEs via group based signaling, and providing the configuration to other UE group via dedicated signaling.

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 method for paging and point to multi-point (PTM) multicast configuration update for multicast/broadcast service (MBS) multicast service reception in radio resource control (RRC) inactive state performed by a communication network system, comprising:

categorizing by a base station, the user equipments (UEs) the UEs based on their preferred reception multicast service preference and/or the knowledge of current their RRC states into different or groups; and

defining the appropriate action or mechanisms to alleviate/reduce the congestion in random access channel (RACH) uplink Uu radio interface and/or the signaling load in the downlink Uu radio interface.
A method for paging and point to multi-point (PTM) multicast configuration update for multicast/broadcast service (MBS) multicast service reception in radio resource control (RRC) inactive state performed by a communication network system, comprising:

to reduce the congestion in random access channel (RACH) uplink Uu radio interface, the base station paging UEs within one group in different time than other UEs in another group so that they trigger RRC connection resume procedure toward a gNB in different time.
A method for paging and point to multi-point (PTM) multicast configuration update for multicast/broadcast service (MBS) multicast service reception in radio resource control (RRC) inactive state performed by a communication network system, comprising:

to reduce the signaling load in the downlink Uu radio interface which occurs due to transmission of multiple PTM configurations individually to a UE in a dedicated manner; a base station providing the PTM configuration update to a group of UEs via group based signaling, and providing the configuration to other UE group via dedicated signaling.
The method according to any one of claims 1 to 3, wherein UE preferred reception multicast service mode is provided from the UE via RRC signaling.
The method according to any one of claims 1 to 4, wherein upon a reception of a multicast service announcement or an activation from a network, the UE indicates to the network, via a service request or a session join procedure in a non-access stratum (NAS) signaling, UE’s preferred multicast service RRC reception mode.
The method according to claim 5, wherein the network provides UE preferred reception multicast service mode and/or a quality of service (QoS) related information via NG-C-NG-U or N2/N3 signaling to a radio access network (RAN) node or the base station.
The method according to any one of claims 1 to 6, wherein the base station categorizes the UEs into

group 1: UEs in an inactive state and preferring a multicast reception in the inactive state;

group 2: UEs in the inactive state and preferring the multicast reception in a connected state;

group 3: UEs in the connected state and preferring the multicast reception in the inactive state; and

group 4: UEs in the connected state and preferring the multicast reception in the connected state.
The method according to any one of claims 1 to 7, wherein the PTM configuration comprises a medium access control (MAC) entity configuration, a set of logical channels with associated radio link control (RLC) entities configurations and physical (PHY) channel configurations for MBS radio bearer (MRB) of a multicast session which the UE has joined for multicast service reception in an inactive or connected mode.
The method according to any one of claims 1 to 8, wherein the group based signaling comprises a PTM configuration carried within MBS control channel (MCCH) and the configuration update is addressed via downlink control information (DCI) within the MCCH while the scheduling of MCCH is provided via a specific system information block (SIB) .
The method according to any one of claims 1 to 9, wherein the dedicated RRC signaling comprises a PTM configuration carried within an RRC signaling message.
The method according to any one of claims 1 to 10, wherein the configuration of the time slot for paging in different group category is according to at least one of the following options:

paging groups UE category in a different paging occasion within a paging frame; and

paging groups UE category in a different paging frame.
The method according to any one of claims 1 to 11, wherein to reduce system load in downlink when providing the PTM configurations to a large number of UEs in a cell, a base station provides a PTM configuration update to a UE group via a dedicated signaling and to other UE group via a group based signaling.
A communication network system, comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver;

wherein the processor is configured to execute the method of any one of claims 1 to 12.
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 1 to 12.
A chip, comprising:

a processor, configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute the method of any one of claims 1 to 12.
A computer readable storage medium, in which a computer program is stored, wherein the computer program causes a computer to execute the method of any one of claims 1 to 12.
A computer program product, comprising a computer program, wherein the computer program causes a computer to execute the method of any one of claims 1 to 12.
A computer program, wherein the computer program causes a computer to execute the method of any one of claims 1 to 12.