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JP-7857401-B2 - Managing the reception of multicast and/or broadcast services after state transitions.

JP7857401B2JP 7857401 B2JP7857401 B2JP 7857401B2JP-7857401-B2

Inventors

  • チー－シャン・ウ
  • テミン・チェン

Assignees

  • グーグル エルエルシー

Dates

Publication Date
20260512
Application Date
20221021
Priority Date
20211021

Claims (11)

  1. A method for managing multicast and/or broadcast service (MBS) communications after state transitions, performed by user equipment (UE), The steps include: receiving MBS data from a wireless access network (RAN) using MBS configuration parameters while the UE is connected to the RAN; The step of transitioning from the aforementioned connected state to an idle state, While the UE is in the idle state, the UE includes the steps of continuing to receive or not receiving MBS data using the MBS configuration parameter , based on whether the MBS configuration parameter is for ( i) receiving broadcast MBS sessions or (ii) receiving unicast or multicast MBS sessions, respectively. The method described above is When the MBS configuration parameter is for receiving a broadcast MBS session, the steps include: retaining the MBS configuration parameter and continuing to receive MBS data using the MBS configuration parameter; A method comprising the step of releasing the MBS configuration parameter when the MBS configuration parameter is for receiving a unicast or multicast MBS session.
  2. The method according to claim 1, further comprising the step of not continuing to receive MBS data using the MBS configuration parameter when the MBS configuration parameter is for receiving a multicast MBS session.
  3. The method according to claim 1, further comprising the step of not continuing to receive MBS data using the MBS configuration parameter when the MBS configuration parameter is for receiving a unicast MBS session.
  4. A method for managing multicast and/or broadcast service (MBS) communications after state transitions, performed by user equipment (UE), The steps include: receiving MBS data from a wireless access network (RAN) using MBS configuration parameters while the UE is connected to the RAN; The step of transitioning from the connected state to an inactive state, While the UE is in the inactive state, the UE includes the steps of continuing to receive or ceasing to receive MBS data using the MBS configuration parameter, based on whether the MBS configuration parameter is for (i) receiving broadcast MBS sessions or (ii) receiving unicast or multicast MBS sessions, respectively. The method described above is When the MBS configuration parameter is for receiving a broadcast MBS session, the steps include: retaining the MBS configuration parameter and continuing to receive MBS data using the MBS configuration parameter; A method comprising the steps of retaining the MBS configuration parameter and discontinuing the use of the MBS configuration parameter when the MBS configuration parameter is for receiving a unicast or multicast MBS session.
  5. The method according to claim 4, further comprising the step of not continuing to receive MBS data using the MBS configuration parameter when the MBS configuration parameter is for receiving a multicast MBS session.
  6. The method according to claim 4, further comprising the step of not continuing to receive MBS data using the MBS configuration parameter when the MBS configuration parameter is for receiving a unicast MBS session.
  7. A method for managing multicast and/or broadcast service (MBS) communications after state transitions, performed by user equipment (UE), The steps include: receiving MBS data from a wireless access network (RAN) using MBS configuration parameters while the UE is connected to the RAN; The steps include receiving a radio resource control (RRC) release message from the aforementioned RAN, The steps include transitioning from the connected state to an idle state or an inactive state in response to the RRC release message, While the UE is in the idle state or the inactive state, the UE includes the steps of continuing to receive or not continuing to receive MBS data using the MBS configuration parameter, based on whether the MBS configuration parameter is for (i) receiving broadcast MBS sessions or (ii) receiving unicast or multicast MBS sessions, respectively. The method described above is When the RRC release message indicates a transition to the idle state, (i) the transition step includes a step of transitioning to the idle state, and (ii) the method includes a step of holding or releasing the MBS configuration parameter, based on whether the MBS configuration parameter is for (i) receiving a broadcast MBS session or (ii) receiving a unicast or multicast MBS session, method.
  8. When the RRC release message indicates a transition to the inactive state, (i) the transition step includes a step of transitioning to the inactive state, and (ii) the method includes a step of holding the MBS configuration parameter and continuing to use or not using the MBS configuration parameter to receive MBS data, based on whether the MBS configuration parameter is for (i) receiving a broadcast MBS session or (ii) receiving a unicast or multicast MBS session, respectively. The method according to claim 7.
  9. The method according to claim 7 , further comprising the step of not continuing to receive MBS data using the MBS configuration parameter when the MBS configuration parameter is for receiving a multicast MBS session.
  10. The method according to claim 7 , further comprising the step of not continuing to receive MBS data using the MBS configuration parameter when the MBS configuration parameter is for receiving a unicast MBS session.
  11. A user device (UE) configured to carry out the method described in any one of claims 1 to 10.

Description

This disclosure relates to wireless communications, and more specifically, to configuration parameters for multicast and/or broadcast services (MBS) and to managing the reception of MBS after state transitions. The background art provided herein is intended to provide a general overview of the context of this disclosure. The research of the inventors named herein, to the extent described in this background art section, is not expressly or implicitly considered prior art to this disclosure, as is the case with respect to aspects of this specification where, in some cases, prior art may not be considered prior art at the time of filing. In telecommunications systems, the Packet Data Convergence Protocol (PDCP) sublayer of the radio protocol stack provides services such as the transfer, encryption, and integrity protection of user plane data. For example, the PDCP layer defined for Advanced Universal Terrestrial Radio Access (EUTRA) radio interfaces (see 3GPP specification TS 36.323) and New Radio (NR) (see 3GPP specification TS 38.323) provides sequencing of protocol data units (PDUs) in the uplink direction (from user devices, also known as user equipment (UEs), to base stations) and in the downlink direction (from base stations to UEs). Furthermore, the PDCP sublayer provides services for signaling radio bearers (SRBs) to the Radio Resource Control (RRC) sublayer. The PDCP sublayer also provides services for data radio bearers (DRBs) to protocol layers such as the Service Data Adaptive Protocol (SDAP) sublayer or the Internet Protocol (IP) layer, Ethernet Protocol layer, or Internet Control Message Protocol (ICMP) layer. Generally, UEs and base stations can use SRBs to exchange RRC and Non-Access Layer (NAS) messages, and DRBs to transport data on the user plane. The RRC sublayer specifies three states: RRC_IDLE, where the UE does not have an active radio connection with a base station; RRC_CONNECTED, where the UE has an active radio connection with a base station; and RRC_INACTIVE, which allows the UE to transition back to the RRC_CONNECTED state more quickly through base station coordination and RAN paging procedures at the Radio Access Network (RAN) level. In some scenarios, a UE can operate in a state where its radio resource control connection with the RAN is inactive (e.g., RRC_IDLE or RRC_INACTIVE) and then transition to a connected state. Generally, in the inactive state, the radio connection between the UE and the RAN is suspended. Later, when the UE is triggered to send data (e.g., an outgoing phone call, a browser launch) or receives a paging message from the base station, the UE can then transition to a connected state. To perform this transition, the UE can request the base station to establish a radio connection (e.g., by sending an RRC setup request message) or resume the suspended radio connection (e.g., by sending an RRC resume request message), and as a result, the base station can configure the UE to operate in a connected state. In some cases, a UE in the RRC_IDLE or RRC_INACTIVE state has only one packet (or a relatively small packet) to send, or a base station has only one packet (or a relatively small packet) to send to a UE operating in the RRC_IDLE or RRC_INACTIVE state. In these cases, the UE in the RRC_IDLE or RRC_INACTIVE state can perform early data communication without transitioning to the RRC_CONNECTED state by using, for example, the techniques specified in 3GPP specification 36.300 v16.4.0 sections 7.3a–7.3d. Base stations operating under the requirements of 5G New Radio (NR) support significantly larger bandwidths than 4G base stations. Therefore, the 3G Partnership Project (3GPP®) proposes for Release 15 that UEs support 100MHz bandwidth in frequency range 1 (FR1) and 400MHz bandwidth in frequency range 2 (FR2). Due to the relatively wide bandwidth of typical carriers in 5G NR, 3GPP® proposes for Release 17 that 5G NR base stations can provide multicast and/or broadcast services (MBS) to UEs. MBS can be useful in many content delivery applications, such as transparent IPv4/IPv6 multicast distribution, IPTV, software distribution over wireless, group communications, Internet of Things (IoT) applications, V2X applications, and emergency messaging related to public safety. 5G NR provides both point-to-point (PTP) and point-to-multipoint (PTM) distribution methods for transmitting MBS packet flows over the radio interface. In PTP communication, a RAN node sends different copies of each MBS data packet to different UEs via the radio interface, while in PTM communication, a RAN node sends a single copy of each MBS data packet to multiple UEs via the radio interface. However, it remains unclear how base stations and UEs handle configuration parameters in certain scenarios when an UE transitions from one state to another, for example, from the RRC_CONNECTED state to the RRC_IDLE or RRC_INACTIVE state, or from the RRC_INACTIVE state to the RRC_IDLE state. 3GPP specification TS 36.