WO2022077444A1

WO2022077444A1 - Method and device for dynamicaly switching multicast and broadcast service (mbs) data packet delivery modes

Info

Publication number: WO2022077444A1
Application number: PCT/CN2020/121531
Authority: WO
Inventors: Xin Zhang; Jia SHENG
Original assignee: JRD Communication (Shenzhen) Ltd.
Priority date: 2020-10-16
Filing date: 2020-10-16
Publication date: 2022-04-21
Also published as: CN116391408A

Abstract

Disclosed are a base station, a user equipment (UE) and a method for dynamically switching Multicast and Broadcast Service (MBS) data packet delivery modes. The method includes: in response to no radio bearer of the MBS having been configured, transmitting a first message for the UE to establish a radio bearer corresponding to an initial delivery mode, wherein the delivery mode is a point-to-point (PTP) mode, a point-to-multipoint (PTM) mode or a combination of PTP and PTM; and in response to radio bearers having been configured, transmitting a second message indicating configuration information representative of one or more operations based on a difference between the initial delivery mode and a target delivery mode for the UE to switch to the target delivery mode. The method realizes dynamic change of MBS data packet delivery between multicast (PTM) and unicast (PTP) with service continuity for a given UE.

Description

METHOD AND DEVICE FOR DYNAMICALY SWITCHING MULTICAST AND BROADCAST SERVICE (MBS) DATA PACKET DELIVERY MODES

Technical Field

The present disclosure relates to wireless communication, and more particularly, to a base station, a user equipment (UE) and a method for dynamically switching Multicast and Broadcast Service (MBS) data packet delivery modes.

Background Art

Wireless communication systems, such as the third-generation (3G) of mobile telephone standards and technology are well known. Such 3G standards and technology have been developed by the Third Generation Partnership Project (3GPP) . The 3rd generation of wireless communications has generally been developed to support macro-cell mobile phone communications. Communication systems and networks have developed towards being a broadband and mobile system. In cellular wireless communication systems, user equipment (UE) is connected by a wireless link to a radio access network (RAN) . The RAN includes a set of base stations (BSs) which provide wireless links to the UEs located in cells covered by the base station, and an interface to a core network (CN) which provides overall network control. The RAN and CN each conducts respective functions in relation to the overall network.

The 3rd Generation Partnership Project has developed the so-called Long Term Evolution (LTE) system, namely, an Evolved Universal Mobile Telecommunication System Territorial Radio Access Network, (E-UTRAN) , for a mobile access network where one or more macro-cells are supported by a base station known as an eNodeB or eNB (evolved NodeB) . More recently, LTE is evolving further towards the so-called 5G or NR (new radio) systems where one or more cells are supported by a base station known as a next generation Node B called gNodeB (gNB) .

The 5G standard will support a multitude of different services each with very different requirements. These services include Enhanced Mobile Broadband (eMBB) for high data rate transmission, Ultra-Reliable Low Latency Communication (URLLC) for devices requiring low latency and high link reliability and Massive Machine-Type Communication (mMTC) to support a large number of low-power devices for a long life-time requiring highly energy efficient communication.

The first and second 3GPP release of 5G technology (3GPP Release 15 and Release 16) only support unicast communications or point-to-point (PTP) transmissions for data packets. The so-called unicast means that information is transmitted point-to-point. Distributing the same data to multiple UEs or devices using above technique would result in inefficient service provisioning, and utilization of the network and spectrum resources. For instance, 10 resources will be needed if a data packet is sent to 10 users in the form of unicast. The utilization of system resources is really low. Both broadcast and multicast data packets belong to point-to-multipoint (PTM) transmission. The difference is that broadcast is to transmit information to all UEs or devices while multicast is to transmit information to UEs or devices in a group. In an example, only 1 resource may be needed if a data packet is sent to 10 users in the form of multicast and broadcast. This greatly improves the utilization of system resources. The PTM transmission is needed to realize flexible multicast/broadcast services in the fields of media and entertainment (M&E) , automotive, Internet-of-Things IoT (machine-type communications) and Public Warning (PW) , for example.

At RAN#86, a new work item on the support of NR Multicast and Broadcast was approved. Based on the related discussion at SA2 for 5G Multicast and Broadcast Service (MBS) , there are two delivery methods for the transmission of MBS packet flows over radio as illustrated in FIG. 1:

- PTM delivery method: a RAN node delivers a single copy of MBS data packets over radio to a set of UEs.

- PTP delivery method: a RAN node delivers separate copies of MBS data packet over radio to individual UE.

The RAN node (e.g., gNB) may use PTM, PTP or a combination of PTP/PTM mode to deliver the MBS data of a particular MBS to the interested UEs within a cell. The support of the simultaneous PTP/PTM delivery method is to cater for the diverse handling for the UEs for the MBS service reception e.g., radio resource utilization scheme, different QoS requirements.

In 3GPP Release 17, Multicast and Broadcast Services will include the following set of objectives:

- Specify RAN basic functions for broadcast/multicast for UEs in RRC_CONNECTED state [RAN1, RAN2, RAN3] :

○ Specify a group scheduling mechanism to allow UEs to receive Broadcast/Multicast service [RAN1, RAN2]

■ This objective includes specifying necessary enhancements that are required to enable simultaneous operation with unicast reception.

○ Specify support for dynamic change of Broadcast/Multicast service delivery between multicast (PTM) and unicast (PTP) with service continuity for a given UE [RAN2, RAN3]

○ Specify support for basic mobility with service continuity [RAN2, RAN3]

○ Assuming that the necessary coordination function (like functions hosted by MCE, if any) resides in the gNB-CU, specify required changes on the RAN architecture and interfaces, considering the results of the SA2 SI on Broadcast/Multicast (SP-190625) [RAN3]

○ Specify required changes to improve reliability of Broadcast/Multicast service, e.g. by UL feedback. The level of reliability should be based on the requirements of the application/service provided. [RAN1, RAN2]

○ Study the support for dynamic control of the Broadcast/Multicast transmission area within one gNB-DU and specify what is needed to enable it, if anything [RAN2, RAN3]

- Specify RAN basic functions for broadcast/multicast for UEs in RRC_IDLE/RRC_INACTIVE states [RAN2, RAN1] :

○ Specify required changes to enable the reception of Point to Multipoint transmissions by UEs in RRC_IDLE/RRC_INACTIVE states, with the aim of keeping maximum commonality between RRC_CONNECTED state and RRC_IDLE/RRC_INACTIVE state for the configuration of PTM reception. [RAN2, RAN1] .

Why dynamic change of broadcast/multicast service delivery between PTM and PTP is needed is explained below. A specific service is sometimes suitable for unicast transmission and sometimes suitable for broadcast-multicast transmission. If the number of users receiving the service at a certain time is relatively large, the system is more appropriate to use PTM transmission; if the number of users receiving the service at the next time is very small, the system can switch to PTP transmission. 33GPP Release 17 requires that unicast and broadcast multicast can be dynamically switched and ensure business continuity. For example, the service has been using broadcast-multicast (i.e., PTM) transmission for some time. As the number of users receiving the service decreases, the network converts the service to unicast (i.e., PTP) . The service can still be guaranteed during the conversion process from broadcast/multicast to unicast.

Accordingly, there is a need to develop a mechanism to realize the dynamic switching between PTM and PTP.

Technical Problem

The objective of the present disclosure is to provide a base station, a user equipment (UE) and a method for dynamically switching Multicast and Broadcast Service (MBS) data packet delivery modes, for realizing dynamic change of MBS delivery between multicast (PTM) and unicast (PTP) with service continuity.

Technical Solution

A first aspect of the present disclosure provides a method for dynamically switching Multicast and Broadcast Service (MBS) data packet delivery modes, wherein MBS data packets are delivered from a base station to a user equipment (UE) in a new radio (NR) communication system, the method performed by the base station and including: in response to no radio bearer of the MBS having been configured, transmitting to the UE a first message indicating configuration information used to establish a radio bearer corresponding to an initial delivery mode for delivering the MBS data packets, wherein the delivery mode is a point-to-point (PTP) mode, a point-to-multipoint (PTM) mode or a combination of PTP and PTM; and in response to radio bearers that correspond to the PTP mode and the PTM mode and have been configured, transmitting to the UE a second message indicating configuration information representative of one or more operations selected from a set of operations based on a difference between the initial delivery mode and a target delivery mode for switching from the initial delivery mode to the target delivery mode.

A second aspect of the present disclosure provides a method for dynamically switching Multicast and Broadcast Service (MBS) data packet delivery modes, wherein MBS data packets are delivered from a base station to a user equipment (UE) in a new radio (NR) communication system, the method performed by the UE and including: in response to no radio bearer of the MBS having been configured, receiving from the base station a first message indicating configuration information used to establish a radio bearer corresponding to an initial delivery mode for receiving the MBS data packets, wherein the delivery mode is a point-to-point (PTP) mode, a point-to-multipoint (PTM) mode or a combination of PTP and PTM; and in response to radio bearers that correspond to the PTP mode and the PTM mode and have been configured, receiving from the base station a second message indicating configuration information representative of one or more operations selected from a set of operations based on a difference between the initial delivery mode and a target delivery mode for switching from the initial delivery mode to the target delivery mode.

The disclosed method may be implemented in a user equipment or a base station.

The disclosed method may be programmed as computer executable instructions stored in non-transitory computer readable medium. The non-transitory computer readable medium, when loaded to a computer, directs a processor of the computer to execute the disclosed method.

The non-transitory computer readable medium may include at least one from a group consisting of: a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a Read Only Memory, a Programmable Read Only Memory, an Erasable Programmable Read Only Memory, EPROM, an Electrically Erasable Programmable Read Only Memory and a Flash memory.

The disclosed method may be programmed as computer program product, that causes a computer to execute the disclosed method.

Advantageous Effects

The invention provides an efficient way to realize dynamic change of BMS delivery between multicast (PTM) and unicast (PTP) with service continuity, thereby improving service provisioning and utilization of the network and spectrum resources.

Description of Drawings

In order to more clearly illustrate the embodiments of the present disclosure or related art, the following figures that 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 schematic diagram illustrating PTP mode and PTM mode.

FIG. 2A is a schematic diagram illustrating SDAP split based approach.

FIG. 2B is a schematic diagram illustrating PDCP split based approach.

FIG. 2C is a schematic diagram illustrating RLC split based approach.

FIG. 3 is a flowchart of RB establishment based on dedicating signaling.

FIG. 4A is a flowchart of a mode switch from PTP mode to PTM mode based on dedicating signaling.

FIG. 4B is a flowchart of a mode switch from PTM mode to PTP mode based on dedicating signaling.

FIG. 4C is a flowchart of a mode switch from PTP mode to a combination of PTP and PTM based on dedicating signaling.

FIG. 4D is a flowchart of a mode switch from PTM mode to a combination of PTM and PTP based on dedicating signaling.

FIG. 4E is a flowchart of a mode switch from a combination of PTP and PTM to PTM mode based on dedicating signaling.

FIG. 4F is a flowchart of a mode switch from a combination of PTP and PTM to PTP mode based on dedicating signaling.

FIG. 5 is a flowchart of a mode switch from PTP mode to PTM mode based on dedicating signaling.

FIG. 6A is a flowchart of a mode switch from PTP mode to PTM mode based on broadcast signaling.

FIG. 6B is a flowchart of a mode switch from PTP mode to PTM mode based on SC-MCCH likely mechanism.

FIG. 7 is a flowchart of a mode switch from PTP mode to PTM mode based on broadcast signaling.

FIG. 8 is a flowchart of a mode switch from PTP mode to PTM mode based on MAC CE.

FIG. 9A shows an example for one-octet MAC CE.

FIG. 9B shows an example for two-octet MAC CE.

FIG. 10 is a flowchart of a mode switch from PTP mode to PTM mode based on DCI.

FIG. 11A is a flowchart of contention-based RAP.

FIG. 11A is a flowchart of 2-step contention-based RAP.

FIG. 12 is a block diagram of an example system for wireless communication according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the 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.

The invention provides a method for dynamically switching Multicast and Broadcast Service (MBS) data packet delivery modes. The method can be realized both in a base station and a user equipment (UE) that may be located in a new radio (NR) communication system, for example. The delivery modes may include a point-to-point (PTP) mode, a point-to-multipoint (PTM) mode and a combination of PTP and PTM for delivering MBS data packets from the base station to the UE. Two conditions have to be considered in making a switch between these modes, that is, (a) no radio bearer (RB) of a multicast service has been configured or no RB configuration has been stored; and (b) RBs has been configured or RB configuration has been stored. The invention provides different mechanisms to realize mode switch in consideration of above two conditions. In condition (a) , the mode switch is associated with RB establishment/addition/modification/release. In condition (b) , the mode switch is associated with RB activation/deactivation. The invention provides such an efficient way to realize dynamic change of BMS delivery between multicast (PTM) and unicast (PTP) with service continuity, thereby improving service provisioning and utilization of the network and spectrum resources.

In this disclosure, solutions for Radio Bear configurations and how dynamic switching can be supported between PTM and PTP are introduced.

MBS RADIO BEAR MODELLING

In 5G NR network and Protocol architecture, a protocol stack includes Service Data Adaptation Protocol (SDAP) , Packet Data Convergence Protocol (PDCP) , Radio link control (RLC) , Media Access Control (MAC) and physical (PHY) layer. The following three approaches may be utilized for MBS radio bear modelling, that is, SDAP split based approach, PDCP split based approach and RLC split based approach. These approaches are associated with a split of protocol stacks for PTP and PTM transmissions and which layer or layers of protocols are shared by PTP protocol stack (PTP leg) and PTM protocol stack (PTM leg) .

1. SDAP split based approach

Referring to FIG. 2A, a common SDAP is used for PTM and PTP transmission for a multicast service, and network routing SDAP Protocol Data Units (PDUs) to PTP or PTM PDCP entity. That is, as indicated in FIG. 2A, at a Radio Access Network (RAN) node (e.g., a base station) , SDAP PDUs are routed to PTP leg and PTM leg; at UE side, PDCP PDUs from PTP leg and PTM leg are routed to a common or shared SDAP.

2. PDCP split based approach

Referring to FIG. 2B, common SDAP and PDCP are used for PTM and PTP transmission for a multicast service, and network routing PDCP PDUs to PTP or PTM RLC entity. That is, as indicated in FIG. 2B, at a RAN node (e.g., a base station) , PDCP PDUs are routed to PTP leg and PTM leg; at UE side, RLC PDUs from PTP leg and PTM leg are routed to common or shared SDAP and PDCP.

3. RLC split based approach

Referring to FIG. 2C, common SDAP, PDCP and RLC are used for PTM and PTP transmission for a multicast service, and network map RLC PDUs to different logical channels. That is, as indicated in FIG. 2C, at a RAN node (e.g., a base station) , RLC PDUs maps to the logical channels for PTP transmission and the logical channels for PTM transmission; at UE side, data flows form logical channels for PTP transmission and PTM transmission are routed to common or shared SDAP, PDCP and RLC.

No matter which MSB radio bearer model is specified, unified configuration and mode switch mechanism can be specified. Unless otherwise specified, PTM leg and PTP leg are referred to as MRB and DRB separately for simplification, that is, in this disclosure,

- DRB stands for PTP protocol stack,

- MRB stands for PTM protocol stack, and

- RB establishment includes SDAP, PDCP, RLC, MAC sublayers.

PROCEDURE

The overall concept of invention is illustrated in Table 1 below. For delivering MBS data packets to the UE, the base station decides which mode (PTP mode, PTM mode or a combination of PTP and PTM) is used to transmit the MBS data packets to the UE. If no RB (s) is established, the base station has to establish the RB corresponding to the decided mode first. If the base station decides to switch to another mode to deliver the MBS data packets, and if any RB or any of RBs corresponding to the another mode has not been established, the RB may instruct the UE to do one or more operations selected from a first set of operations (establishment/addition/modification/release) to carry out the mode switch. If RBs has been established, the RB may instruct the UE to do one or more operations selected from a second set of operations (activation/deactivation) to carry out the mode switch.

Table 1

Step 1: Before initial RB established, if RBs have been configured/RB configuration has been stored.

If no (①) , the base station (e.g., gNB) needs to decide the mode and establish the RB first, then switch the mode when necessary (③) .

If yes (②) , the base station (e.g., gNB) switches the mode via activation and deactivation of the RB (④) .

Step 2: Mode switch

The base station may utilize different approaches to instruct the UE to perform the operations to carry out the mode switch. These approaches are classified as illustrated in Table 2 below.

Table 2

1. For RB establishment/addition/modification/release (③) ,

(1) when gNB decides to make the switch, RBs addition and release are needed, including first addition then release and first release then addition.

(2) the solutions for mode switch indication include dedicated signaling (⑤) and broadcast signaling (⑥) .

2. For RB activation/deactivation (④) ,

(1) when gNB decides to make the switch, RBs activation and deactivation are needed, including first activation then deactivation and first deactivation then activation.

(2) The solutions for mode switch indication include dedicated signaling (⑦) , broadcast signaling (⑧) , MAC-CE (⑨) and DCI (⑩) .

(3) DCI includes G-RNTI (⑩-①) and C-RNTI (⑩-②) .

Specifically, dedicated signaling/RRC signaling (⑤, ⑦) includes approaches as illustrated in Table 3 below.

Table 3

Specifically, broadcast signaling/SIB (⑥, ⑧) includes approaches as illustrated in Table 4 below.

Table 4

Specifically, the ways to acquire G-RNTI (⑩-①) include broadcast signaling and RACH, as illustrated in Table 5 below.

Table 5

MODE SWITCH SCENARIOS/USE CASES

The mode for delivering MBS data packets may be switched from an initial delivery mode to a target delivery mode. For example, the base station initially uses PTP mode to deliver the data and decides to switch to PTM; the base station initially uses PTM mode to deliver the data and decides to switch to PTP; the base station initially uses PTP mode to deliver the data and decides to switch to a combination of PTP and PTM; the base station initially uses PTM mode to deliver the data and decides to switch to a combination of PTM and PTP; the base station initially uses a combination of PTP and PTM to deliver the data and decides to switch to PTM; the base station initially uses a combination of PTP and PTM to deliver the data and decides to switch to PTP. These mode switch scenarios/user cases are listed below.

1. PTP->PTM

2. PTM->PTP

3. PTP->PTP+PTM

4. PTM->PTM+PTP

5. PTP+PTM->PTM

6. PTP+PTM->PTP

EMBODIMENTS

1. Dedicated signaling/RRC signaling for ⑤

If no RB of the MBS has been configured, the base station may transmit and the UE may receive a message indicating configuration information for establishing an RB corresponding to an initial delivery mode (PTP mode, PTM mode or a combination of PTP and PTM) for delivering the MBS data packets. After that, if the base station decides to switch to a target delivery mode (PTP mode, PTM mode or a combination of PTP and PTM) , the base station may transmit and the UE may receive a message to instruct the UE to do one or more operations (establishment/addition/modification/release) for switching from the initial delivery mode to the target delivery mode for delivering the MBS data packets. The message for mode switch indicates configuration information representative of one or more operations selected from a set of operations including establishing/adding/modifying/releasing operations. The one or more operations are decided based on a difference between the initial delivery mode and the target delivery mode. Any of the messages may be transmitted from the base station to the UE by dedicated signaling or Radio Resource Control (RRC) signaling.

1.1 First step for ⑤: initial RB establishment/configured

FIG. 3 is a flowchart of RB establishment based on dedicating signaling. As illustrated in FIG. 3, gNB decides a delivery mode, which can be PTP mode, PTM mode or a combination of PTP and PTM. The gNB transmits a RRC message to the UE by dedicating signaling or RRC signaling to instruct the UE to establish an RB (DRB/MRB/both DRB and MRB) corresponding to the decided delivery mode. Once the RB is established, the UE reports to the gNB that the establishment is completed.

In an embodiment, the RRC messsage is a RRCreconfiguration message and the configuration information carried on the RRCreconfiguration messag to establish the RB is indicated by an information element (e.g., radioBearerConfig) of the RRCreconfiguration message. The information element radioBearerConfig may include parameters such as drb-ToAddModList and drb-ToReleaseList for instructing the RB establishmenet.

In an emdboment, the RRC messsage is a RRCresume message and the configuration information carried on the RRCresume message to establish the RB is indicated by an information element (e.g., radioBearerConfig) of the RRCresume message. The information element radioBearerConfig may include parameters such as drb-ToAddModList and drb-ToReleaseList for instructing the RB establishmenet.

1.2 RB addition/release/modification (⑤)

(1) PTP->PTM

FIG. 4A is a flowchart of a mode switch from PTP mode to PTM mode based on dedicating signaling. As illustrated in FIG. 4A, if the initial delivery mode is PTP mode and the gNB decides to switch to PTM mode, the gNB may transmit a RRC message to the UE by dedicating signaling or RRC signaling to instruct the UE to perform the mode switch. The RRC message indicates configuration information representative of a releasing operation to release DRB corresponding to the PTP mode and an establishing operation to establish MRB corresponding to the PTM mode. DRB may be released first and then MRB is established; alternatively, MRB may be established first and then DRB is released.

(2) PTM->PTP

FIG. 4B is a flowchart of a mode switch from PTM mode to PTP mode based on dedicating signaling. As illustrated in FIG. 4B, if the initial delivery mode is PTM mode and the gNB decides to switch to PTP mode, the gNB may transmit a RRC message to the UE by dedicating signaling or RRC signaling to instruct the UE to perform the mode switch. The RRC message indicates configuration information representative of a releasing operation to release MRB corresponding to the PTM mode and an establishing operation to establish DRB corresponding to the PTP mode. MRB may be released first and then DRB is established; alternatively, DRB may be established first and then MRB is released.

(3) PTP->PTP+PTM

FIG. 4C is a flowchart of a mode switch from PTP mode to a combination of PTP and PTM based on dedicating signaling. As illustrated in FIG. 4C, if the initial delivery mode is PTP mode and the gNB decides to switch to PTP+PTM mode, the gNB may transmit a RRC message to the UE by dedicating signaling or RRC signaling to instruct the UE to perform the mode switch. The RRC message indicates configuration information representative of an establishing operation to only establish MRB corresponding to the PTM mode to carry out switching to the PTP+PTM mode.

(4) PTM->PTM+PTP

FIG. 4D is a flowchart of a mode switch from PTM mode to a combination of PTM and PTP based on dedicating signaling. As illustrated in FIG. 4D, if the initial delivery mode is PTM mode and the gNB decides to switch to PTM+PTP mode, the gNB may transmit a RRC message to the UE by dedicating signaling or RRC signaling to instruct the UE to perform the mode switch. The RRC message indicates configuration information representative of an establishing operation to only establish DRB corresponding to the PTP mode to carry out switching to the PTM+PTP mode.

(5) PTP+PTM->PTM

FIG. 4E is a flowchart of a mode switch from a combination of PTP and PTM to PTM mode based on dedicating signaling. As illustrated in FIG. 4E, if the initial delivery mode is PTP+PTM mode and the gNB decides to switch to PTM mode, the gNB may transmit a RRC message to the UE by dedicating signaling or RRC signaling to instruct the UE to perform the mode switch. The RRC message indicates configuration information representative of a releasing operation to only release DRB corresponding to the PTP mode to carry out switching to the PTM mode.

(6) PTP+PTM->PTP

FIG. 4F is a flowchart of a mode switch from a combination of PTP and PTM to PTP mode based on dedicating signaling. As illustrated in FIG. 4F, if the initial delivery mode is PTP+PTM mode and the gNB decides to switch to PTP mode, the gNB may transmit a RRC message to the UE by dedicating signaling or RRC signaling to instruct the UE to perform the mode switch. The RRC message indicates configuration information representative of a releasing operation to only release MRB corresponding to the PTM mode to carry out switching to the PTP mode.

Similar to the initial RB establishment, the gNB may transmit the message for mode switch to the UE by dedicated signaling to instruct the UE to perform the mode switch and the message for mode switch is a RRC message such as the RRCreconfiguration message and the RRCresume message described above.

2. Dedicated signaling/RRC signaling for ⑦

It RBs of the MBS corresponding to the PTP mode and the PTM mode have been configured, that is, DRB and MRB have been configured or established previously, the base station may transmit and the UE may receive a message to instruct the UE to do one or more operations (activation/deactivation) for switching from the initial delivery mode to the target delivery mode for delivering the MBS data packets. The message indicates configuration information representative of one or more operations selected from a set of operations including activating/deactivating operations. The one or more operations are decided based on a difference between the initial delivery mode and the target delivery mode. The message for mode switch may be transmitted from the base station to the UE by dedicated signaling or Radio Resource Control (RRC) signaling.

Flow chart: PTP->PTM

FIG. 5 is a flowchart of a mode switch from PTP mode to PTM mode based on dedicating signaling. As illustrated in FIG. 5, if the initial delivery mode is PTP mode and the gNB decides to switch to PTM mode, and if both MRB and DRM configurations have been stored, the gNB may transmit a RRC message to the UE by dedicating signaling or RRC signaling to instruct the UE to perform the mode switch. The RRC message indicates configuration information representative of a deactivating operation to deactivate DRB corresponding to the PTP mode and an activating operation to activate MRB corresponding to the PTM mode. DRB may be deactivated first and then MRB is activated; alternatively, MRB may be activated first and then DRB is deactivated.

Other scenarios such as PTM->PTP, PTP->PTP+PTM, PTM->PTM+PTP, PTP+PTM->PTM, PTP+PTM->PTP use the same principle and thus are not detailed herein. For PTP->PTP+PTM and PTM->PTM+PTP, the message for mode switch may indicate configuration information representative of an activating operation only; for PTP+PTM->PTM and PTP+PTM->PTP, the message for mode switch may indicate configuration information representative of a deactivating operation only. These operations are decided based on the difference between the initial delivery mode and the target delivery mode.

Similar to the above, the gNB may transmit the message for mode switch to the UE by dedicated signaling to instruct the UE to perform the mode switch and the message is a RRC message such as the RRCreconfiguration message and the RRCresume message described above. The configuration information carried on the RRCreconfiguration message or the RRCresume message may be indicated by an information element (e.g., radioBearerConfig) , which may include parameters such as drb-ToActiveList and drb-ToDeactiveList.

3. Broadcast signaling for ⑥

If no RB of the MBS has been configured, the base station may transmit and the UE may receive a message for establishing a RB corresponding to an initial delivery mode, and if the base station decides to do mode switch, a message is transmitted to instruct the UE to do one or more operations (establishment/addition/modification/release) for switching from the initial delivery mode to a target delivery mode for delivering the MBS data packets. The one or more operations are decided based on a difference between the initial delivery mode and the target delivery mode. In an embodiment, any of the messages may be transmitted from the base station to the UE by broadcast signaling or System Information Block (SIB) signaling and the message is a SIB message. In another embodiment, the message for RB establishment is transmitted by the broadcast signaling and a control channel configuration is also transmitted to the UE by the broadcast signaling for the UE to establish a control channel based on the control channel configuration, and then the message for mode switch is transmitted on the control channel. The control channel for transmission of the message is carried and sent on a Physical Downlink Shared Channel (PDSCH) .

(1) SIB

Flow chart: PTP->PTM

FIG. 6A is a flowchart of a mode switch from PTP mode to PTM mode based on broadcast signaling. As illustrated in FIG. 6A, gNB transmits a SIB message to the UE by broadcast signaling to instruct the UE to establish an RB (DRB/MRB/both DRB and MRB) corresponding to the decided delivery mode. If the decided delivery mode (i.e., the initial delivery mode) is PTP mode and the gNB decides to switch to PTM mode, the gNB may transmit a SIB message to the UE by broadcast signaling to instruct the UE to perform the mode switch. The SIB message indicates configuration information representative of a releasing operation to release DRB corresponding to the PTP mode and an establishing operation to establish MRB corresponding to the PTM mode. DRB may be released first and then MRB is established; alternatively, MRB may be established first and then DRB is released.

Other scenarios use the same principle and thus are not detailed herein. For PTP->PTP+PTM and PTM->PTM+PTP, the message for mode switch may indicate configuration information representative of an establishing operation only; for PTP+PTM->PTM and PTP+PTM->PTP, the message for mode switch may indicate configuration information representative of a releasing operation only. These operations are decided based on the difference between the initial delivery mode and the target delivery mode. SIBs could be normal SI or on-demand SI.

(2) SC-MCCH likely mechanism

Flow chart: PTP->PTM

FIG. 6B is a flowchart of a mode switch from PTP mode to PTM mode based on SC-MCCH likely mechanism. As illustrated in FIG. 6B, gNB transmits a SIB message to the UE by broadcast signaling to instruct the UE to establish an RB (DRB/MRB/both DRB and MRB) corresponding to the decided delivery mode. A control channel configuration is also transmitted to the UE by the broadcast signaling for the UE to establish a control channel based on the control channel configuration. The control channel may be a Single-Cell Multicast Control Channel (SC-MCCH) or the like carried and sent on the PDSCH. If the decided delivery mode (i.e., the initial delivery mode) is PTP mode and the gNB decides to switch to PTM mode, the gNB may transmit to the UE a message on the control channel such as SC-MCCH or a control channel like SC-MCCH to instruct the UE to perform the mode switch. The message for mode switch indicates configuration information representative of a releasing operation to release DRB corresponding to the PTP mode and an establishing operation to establish MRB corresponding to the PTM mode. DRB may be released first and then MRB is established; alternatively, MRB may be established first and then DRB is released.

Other scenarios use the same principle and thus are not detailed herein. For PTP->PTP+PTM and PTM->PTM+PTP, the message for mode switch may indicate configuration information representative of an establishing operation only; for PTP+PTM->PTM and PTP+PTM->PTP, the message for mode switch may indicate configuration information representative of a releasing operation only. These operations are decided based on the difference between the initial delivery mode and the target delivery mode. SIBs could be normal SI or on-demand SI. “SC-MCCH” is the terminology specified in LTE MBMS.

4. Broadcast signaling for ⑧

It RBs of the MBS corresponding to the PTP mode and the PTM mode have been configured, that is, DRB and MRB have been configured or established previously, the base station may transmit and the UE may receive a message to instruct the UE to do one or more operations (activation/deactivation) for switching from the initial delivery mode to the target delivery mode for delivering the MBS data packets. The message for mode switch indicates configuration information representative of one or more operations selected from a set of operations including activating/deactivating operations. The one or more operations are decided based on a difference between the initial delivery mode and the target delivery mode. In an embodiment, the message for mode switch may be transmitted from the base station to the UE by broadcast signaling or SIB signaling. In another embodiment, the message for mode switch may also be transmitted using the afore-described SC-MCCH likely mechanism.

(1) SIB

Flow chart: PTP->PTM

FIG. 7 is a flowchart of a mode switch from PTP mode to PTM mode based on broadcast signaling. As illustrated in FIG. 7, if the initial delivery mode is PTP mode and the gNB decides to switch to PTM mode, and if both MRB and DRM configurations have been stored, the gNB may transmit a SIB message to the UE by broadcast signaling or SIB signaling to instruct the UE to perform the mode switch. The SIB message indicates configuration information representative of a deactivating operation to deactivate DRB corresponding to the PTP mode and an activating operation to activate MRB corresponding to the PTM mode. DRB may be deactivated first and then MRB is activated; alternatively, MRB may be activated first and then DRB is deactivated.

Other scenarios use the same principle and thus are not detailed herein. For PTP->PTP+PTM and PTM->PTM+PTP, the message for mode switch may indicate configuration information representative of an activating operation only; for PTP+PTM->PTM and PTP+PTM->PTP, the message for mode switch may indicate configuration information representative of a deactivating operation only. These operations are decided based on the difference between the initial delivery mode and the target delivery mode. SIBs could be normal SI or on-demand SI.

(2) SC-MCCH likely mechanism

Based on similar idea introduced above, the message for mode switch may also be transmitted using the afore-described SC-MCCH likely mechanism.

5. MAC CE for ⑨

It RBs of the MBS corresponding to the PTP mode and the PTM mode have been configured, that is, DRB and MRB have been configured or established previously, the base station may transmit and the UE may receive a message indicating configuration information representative of one or more operations for the UE to do the one or more operations (activation/deactivation) for switching from the initial delivery mode to the target delivery mode for delivering the MBS data packets. The configuration information of the message for mode switch may be indicated by a Medium Access Control (MAC) Control Element (CE) .

(1) Flow chart: PTP->PTM

FIG. 8 is a flowchart of a mode switch from PTP mode to PTM mode based on MAC CE. As illustrated in FIG. 8, if the initial delivery mode is PTP mode and the gNB decides to switch to PTM mode, and if both MRB and DRM configurations have been stored, the gNB may transmit a MAC CE to the UE to instruct the UE to perform the mode switch. The MAC CE indicates configuration information representative of a deactivating operation to deactivate DRB corresponding to the PTP mode and an activating operation to activate MRB corresponding to the PTM mode. DRB may be deactivated first and then MRB is activated; alternatively, MRB may be activated first and then DRB is deactivated.

Other scenarios use the same principle and thus are not detailed herein. For PTP->PTP+PTM and PTM->PTM+PTP, the MAC CE may indicate configuration information representative of an activating operation only; for PTP+PTM->PTM and PTP+PTM->PTP, the MAC CE may indicate configuration information representative of a deactivating operation only. These operations are decided based on the difference between the initial delivery mode and the target delivery mode.

(2) MAC CE

A new MAC CE is introduced for MBS RB activation/deactivation. The LCID for this new MAC CE could be added as illustrated in Tables 6, 7 and 8. Table 6 depicts values of LCID for DL-SCH, wherein MBS RB Activation/Deactivation is listed at Index 63. Table 7 depicts values of two-octet eLCID for DL-SCH with MBS RB Activation/Deactivation specified. Table 8 depicts values of one-octet eLCID for DL-SCH with MBS RB Activation/Deactivation specified.

Table 6

Table 7

Codepoint	Index	LCID values
0 to 255	64	MBS RB Activation/Deactivation
0 to 255	64 to 319	reserved

Table 8

Solution 1:

The MAC CE corresponds to one or more octets, a first value of a field of the one or more octets indicates activation of a radio bearer corresponding to one of the PTP mode and the PTM mode and a second value of the field of the one or more octets indicates deactivation of the radio bearer corresponding to the one of the PTP mode and the PTM mode.

The MAC CE could be one to N octets. FIG. 9A shows an example for one-octet MAC CE. For example, the field is set to 1 to indicate the RB shall be activated and the field is set to 0 to indicate the RB shall be deactivated; alternatively, the field is set to 1 to indicate the RB shall be deactivated and the field is set to 0 to indicate the RB shall be activated.

Solution 2:

The MAC CE corresponds to two octets, and a field of one of the two octets indicates activation or deactivation of a radio bearer corresponding to one of the PTP mode and the PTM mode and a field of the other one of the two octets indicates activation or deactivation of a radio bearer corresponding to the other one of the PTP mode and the PTM mode.

FIG. 9B shows an example for two-octet MAC CE. The field to indicate if it is DRB or MRB is introduced. For example, M/D field is introduced to indicate this octet is for MRB or DRB.

6. DCI for ⑩

It RBs of the MBS corresponding to the PTP mode and the PTM mode have been configured, that is, DRB and MRB have been configured or established previously, the base station may transmit and the UE may receive a message indicating configuration information representative of one or more operations for the UE to do the one or more operations (activation/deactivation) for switching from the initial delivery mode to the target delivery mode for delivering the MBS data packets. The message for mode switch may correspond to Downlink Control Information (DCI) transmitted on a Physical Downlink Control Channel (PDCCH) . The DCI includes a Cell Radio Network Temporary Identifier (C-RNTI) configured to identify which UE is to be applied, especially for PTP mode. The DCI copes with a Group Radio Network Temporary Identifier (G-RNTI) configured to identify which group of UEs is to be applied, especially for PTM mode.

(1) Flow chart: PTP->PTM

FIG. 10 is a flowchart of a mode switch from PTP mode to PTM mode based on DCI. As illustrated in FIG. 10, if both MRB and DRM configurations have been stored, and if gNB decides PTP mode as the delivery mode to deliver MBS data packets, the gNB may instruct the UE to do related operations by DCI with C-RNTI such that the UE knows whether the instruction is for it. If the gNB decides to switch from the PTP mode to PTM mode, the gNB may again transmit DCI to the UE to instruct the UE to perform the mode switch. The DCI copes with a G-RNTI to identify which group of UEs is to be applied, and thus the UE knows whether it belongs to the group. The DCI indicates configuration information representative of a deactivating operation to deactivate DRB corresponding to the PTP mode and an activating operation to activate MRB corresponding to the PTM mode. DRB may be deactivated first and then MRB is activated; alternatively, MRB may be activated first and then DRB is deactivated.

Other scenarios use the same principle and thus are not detailed herein. For PTP->PTP+PTM and PTM->PTM+PTP, the DCI may indicate configuration information representative of an activating operation only; for PTP+PTM->PTM and PTP+PTM->PTP, the DCI may indicate configuration information representative of a deactivating operation only. These operations are decided based on the difference between the initial delivery mode and the target delivery mode.

(2) How G-RNTI is acquired

(a) Included in Current SIB, e.g., SIB13, SIB20, or new defined SIBs

The G-RNTI may be transmitted from the gNB to the UE by broadcast signaling in a SIB message. The G-RNTI could be carried on Current SIB, e.g., SIB13, SIB20, or can be included in new defined SIBs.

(b) SC-MCCH likely mechanism:

i. SIBs to indicate “SC-MCCH” configuration

ii. UE to receive “SC-MCCH” which carries G-RNTI

The G-RNTI may be carried on a control channel such as SC-MCCH or a control channel like SC-MCCH on a PDSCH, and a control channel configuration regarding the control channel is transmitted by broadcast signaling using a SIB message.

(c) RACH

The G-RNTI is contained in Msg2 (as depicted in FIG. 11A) or MsgB (as depicted in FIG. 11B) transmitted from the gNB to the UE during a Random Access Channel (RACH) procedure. The G-RNTI and other services and area related information, e.g., Temporary Mobile Group Identity (TMGI) may be transmitted to UE as well.

FIG. 12 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. 12 illustrates the system 700 including a radio frequency (RF) circuitry 710, a baseband circuitry 720, a processing unit 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 as illustrated.

The processing unit 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 5G NR, LTE, 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 UE, eNB, gNB or TRP may be embodied in whole or in part in one or more of the RF circuitries, the baseband circuitry, and/or the processing unit. 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 processing unit, 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.

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 method for dynamicaly switching Multicast and Broadcast Service (MBS) data packet delivery modes, wherein MBS data packets are delivered from a base station to a user equipment (UE) in a new radio (NR) communication system, the method performed by the base station and comprising:

in response to no radio bearer of the MBS having been configured, transmitting to the UE a first message indicating configuration information used to establish a radio bearer corresponding to an initial delivery mode for delivering the MBS data packets, wherein the delivery mode is a point-to-point (PTP) mode, a point-to-multipoint (PTM) mode or a combination of PTP and PTM; and

in response to radio bearers that correspond to the PTP mode and the PTM mode and have beeen configured, transmitting to the UE a second message indicating configuration information representative of one or more operations selected from a set of operations based on a difference between the initial delivery mode and a target delivery mode for switching from the initial delivery mode to the target delivery mode.
The method according to claim 1, during radio bearer configuring stage, the further comprises:

transmitting another message indicating configuration information representative of one or more operations selected from another set of operations based on a difference between the initial delivery mode and the target delivery mode for switching from the initial delivery mode to the target delivery mode.
The method according to claim 2, wherein the the set of operations comprise an activating operation and a deactivating operation, and the another set of operations comprise an establishing operation and a releasing operation.
The method according to claim 2, wherein the step of transmitting the another message comprises:

transmitting the another message indicating configuration information representative of operations to release a radio bearer corresponding to one of the PTP mode and the PTM mode and establish a radio bearer corresponding to the other one of the PTP mode and the PTM mode.
The method according to claim 2, wherein the step of transmitting the another message comprises:

transmitting the another message indicating configuration information representative of an operation to only establish a radio bearer corresponding to one of the PTP mode and the PTM mode in the presence of a radio bearer corresponding to the other one of the PTP mode and the PTM mode.
The method according to claim 2, wherein the step of transmitting the another message comprises:

transmitting the another message indicating configuration information representative of an operation to only release a radio bearer corresponding to one of the PTP mode and the PTM mode in the presence of two radio bearers corresponding to the PTP mode and PTM mode.
The method according to claim 1, wherein the step of transmitting the second message comprises:

transmitting the second message indicating configuration information representative of operations to deactivate a radio bearer corresponding to one of the PTP mode and the PTM mode and activate a radio bearer corresponding to the other one of the PTP mode and the PTM mode.
The method according to claim 1, wherein the step of transmitting the second message comprises:

transmitting the second message indicating configuration information representative of an operation to only activate a radio bearer corresponding to one of the PTP mode and the PTM mode in the presence of a radio bearer corresponding to the other one of the PTP mode and the PTM mode.
The method according to claim 1, wherein the step of transmitting the second message comprises:

transmitting the second message indicating configuration information representative of an operation to only deactivate a radio bearer corresponding to one of the PTP mode and the PTM mode in the presence of two radio bearers corresponding to the PTP mode and PTM mode.
The method according to claim 1, wherein any of the first and second messages is transmitted to the UE by dedicated signaling, and any of the first and second messages is a Radio Resource Control (RRC) message.
The method according to claim 10, wherein any of the first and second messages is a RRCreconfiguration message and the configuration information of any of the first and second messages is indicated by an information element of the RRCreconfiguration message.
The method according to claim 10, wherein any of the first and second messages is a RRCresume message and the configuration information of any of the first and second messages is indicated by an information element of the RRCresume message.
The method according to claim 1, wherein any of the first and second messages is transmitted to the UE by broadcast signaling, and any of the first and second messages is a System Information Block (SIB) message.
The method according to claim 1, further comprising:

transmitting to the UE a control channel configuration, wherein the second message is transmitted on a control channel indicated by the control channel configuration.
The method according to claim 14, wherein the control channel configuration is transmitted by broadcast signaling using a System Information Block (SIB) message, and the control channel for transmission of the second message is carried and sent on a Physical Downlink Shared Channel (PDSCH) .
The method according to claim 1, wherein configuration information of the second message is indicated by a Medium Access Control (MAC) Control Element (CE) .
The method according to claim 16, wherein the MAC CE corresponds to one or more octets, and a first value of a field of the one or more octets indicates activation of a radio bearer corresponding to one of the PTP mode and the PTM mode and a second value of the field of the one or more octets indicates deactivation of the radio bearer corresponding to the one of the PTP mode and the PTM mode.
The method according to claim 16, wherein the MAC CE corresponds to two octets, and a field of one of the two octets indicates activation or deactivation of a radio bearer corresponding to one of the PTP mode and the PTM modee and a field of the other one of the two octets indicates activation or deactivation of a radio bearer corresponding to the other one of the PTP mode and the PTM mode.
The method according to claim 1, wherein the second message corresponds to Downlink Control Information (DCI) transmitted on a Physical Downlink Control Channel (PDCCH) .
The method according to claim 19, wherein the DCI comprises a Cell Radio Network Temporary Identifier (C-RNTI) configured to identify which UE is to be applied.
The method according to claim 19, wherein the DCI copes with a Group Radio Network Temporary Identifier (G-RNTI) configured to identify which group of UEs is to be applied.
The method according to claim 21, wherein the G-RNTI is carried on a control channel on a Physical Downlink Shared Channel (PDSCH) for transmission of the second message, and a control channel configuration regarding the control channel is transmitted by broadcast signaling using a System Information Block (SIB) message.
The method according to claim 21, wherein the G-RNTI is contained in Msg2 or MsgB transmitted from the base station to the UE during a Random Access Channel (RACH) procedure.
A method for dynamicaly switching Multicast and Broadcast Service (MBS) data packet delivery modes, wherein MBS data packets are delivered from a base station to a user equipment (UE) in a new radio (NR) communication system, the method performed by the UE and comprising:

in response to no radio bearer of the MBS having been configured, receiving from the base station a first message indicating configuration information used to establish a radio bearer corresponding to an initial delievey mode for receiving the MBS data packets, wherein the delivery mode is a point-to-point (PTP) mode, a point-to-multipoint (PTM) mode or a combination of PTP and PTM; and

in response to radio bearers that correspond to the PTP mode and the PTM mode and have beeen configured, receiving from the base station a second message indicating configuration information representative of one or more operations selected from a set of operations based on a difference between the initial delivery mode and a target delivery mode for switching from the initial delivery mode to the target delivery mode.
The method according to claim 24, during radio bearer configuring stage, the method further comprises:

receiving another message indicating configuration information representative of one or more operations selected from another set of operations based on a difference between the initial delivery mode and the target delivery mode for switching from the initial delivery mode to the target delivery mode.
The method according to claim 25, wherein the set of operations comprise an activating operation and a deactivating operation, and the another set of operations comprise an establishing operation and a releasing operation.
The method according to claim 25, wherein the step of receiving the another message comprises:

receiving the another message indicating configuration information representative of operations to release a radio bearer corresponding to one of the PTP mode and the PTM mode and establish a radio bearer corresponding to the other one of the PTP mode and the PTM mode.
The method according to claim 25, wherein the step of receiving the another message comprises:

receiving the another message indicating configuration information representative of an operation to only establish a radio bearer corresponding to one of the PTP mode and the PTM mode in the presence of a radio bearer corresponding to the other one of the PTP mode and the PTM mode.
The method according to claim 25, wherein the step of receiving the another message comprises:

receiving the another message indicating configuration information representative of an operation to only release a radio bearer corresponding to one of the PTP mode and the PTM mode in the presence of two radio bearers corresponding to the PTP mode and PTM mode.
The method according to claim 24, wherein the step of receiving the second message comprises:

receiving the second message indicating configuration information representative of operations to deactivate a radio bearer corresponding to one of the PTP mode and the PTM mode and activate a radio bearer corresponding to the other one of the PTP mode and the PTM mode.
The method according to claim 24, wherein the step of receiving the second message comprises:

receiving the second message indicating configuration information representative of an operation to only activate a radio bearer corresponding to one of the PTP mode and the PTM mode in the presence of a radio bearer corresponding to the other one of the PTP mode and the PTM mode.
The method according to claim 24, wherein the step of receiving the second message comprises:

receiving the second message indicating configuration information representative of an operation to only deactivate a radio bearer corresponding to one of the PTP mode and the PTM mode in the presence of two radio bearers corresponding to the PTP mode and PTM mode.
The method according to claim 24, wherein any of the first and second messages is transmitted from the base station by dedicated signaling, and any of the first and second messages is a Radio Resource Control (RRC) message.
The method according to claim 33, wherein any of the first and second messages is a RRCreconfiguration message and the configuration information of any of the first and second messages is indicated by an information element of the RRCreconfiguration message.
The method according to claim 33, wherein any of the first and second messages is a RRCresume message and the configuration information of any of the first and second messages is indicated by an information element of the RRCresume message.
The method according to claim 24, wherein any of the first and second messages is transmitted from the base station by broadcast signaling, and any of the first and second messages is a System Information Block (SIB) message.
The method according to claim 24, further comprising:

receiving from the base station a control channel configuration, wherein the second message is receeived on a control channel indicated by the control channel configuration.
The method according to claim 37, wherein the control channel configuration is transmitted by broadcast signaling using a System Information Block (SIB) message, and the control channel for transmission of the second message is carried and sent on a Physical Downlink Shared Channel (PDSCH) .
The method according to claim 24, wherein configuration information of the second message is indicated by a Medium Access Control (MAC) Control Element (CE) .
The method according to claim 39, wherein the MAC CE corresponds to one or more octets, and a first value of a field of the one or more octets indicates activation of a radio bearer corresponding to one of the PTP mode and the PTM mode and a second value of the field of the one or more octets indicates deactivation of the radio bearer corresponding to the one of the PTP mode and the PTM mode.
The method according to claim 39, wherein the MAC CE corresponds to two octets, and a field of one of the two octets indicates activation or deactivation of a radio bearer corresponding to one of the PTP mode and the PTM modee and a field of the other one of the two octets indicates activation or deactivation of a radio bearer corresponding to the other one of the PTP mode and the PTM mode.
The method according to claim 24, wherein the second message corresponds to Downlink Control Information (DCI) received on a Physical Downlink Control Channel (PDCCH) .
The method according to claim 42, wherein the DCI comprises a Cell Radio Network Temporary Identifier (C-RNTI) configured to identify which UE is to be applied.
The method according to claim 42, wherein the DCI copes with a Group Radio Network Temporary Identifier (G-RNTI) configured to identify which group of UEs is to be applied.
The method according to claim 44, wherein the G-RNTI is carried on a control channel on a Physical Downlink Shared Channel (PDSCH) for transmission of the second message, and a control channel configuration regarding the control channel is transmitted by broadcast signaling using a System Information Block (SIB) message.
The method according to claim 44, wherein the G-RNTI is contained in Msg2 or MsgB transmitted from the base station to the UE during a Random Access Channel (RACH) procedure.
A base station, comprising:

a processor, configured to call and run program instructions stored in a memory, to execute any of the methods of claims 1 to 23.
A user equipment, comprising:

a processor, configured to call and run program instructions stored in a memory, to execute any of the methods of claims 24 to 46.