Point-to-multipoint (PTM) transmissions in wireless communication

1 . A user equipment (UE) for wireless communications, the UE comprising:

a transceiver configured to maintain a first timer and transmit

a first message, as a response to any condition in a first condition set being satisfied;

wherein a condition in the first condition set is that the first timer is expired; wherein the first message is used for indicating at least one non-unicast identifier; wherein the first node is in a first radio resource control (RRC) state when transmitting the first message; wherein the first RRC state is an RRC connected state or an RRC inactive state; and

the transceiver is further configured to receive a first signaling, a second signaling, a first signal and a second signal;

wherein the first signaling is used to determine at least one of time-domain resources or frequency-domain resources occupied by the first signal, while the second signaling is used to determine at least one of time-domain resources or frequency-domain resources occupied by the second signal; wherein overlapping time-domain resources exist between the time-domain resources occupied by the first signal and the time-domain resources occupied by the second signal; wherein the first signaling comprises a first field used to indicate a first reference signal resource and the second signaling comprises a second field used to indicate a second reference signal resource different from the first reference signal resource; wherein a demodulation reference signal (DMRS) of a channel occupied by the first signal is Quasi Co-located (QCL) with a target reference signal resource and a DMRS of a channel occupied by the second signal is QCL with the target reference signal resource; wherein the target reference signal resource is one of the first reference signal resource or the second reference signal resource; and wherein a priority of the first signal and a priority of the second signal are used to determine the target reference signal resource from the first reference signal resource and the second reference signal resource, or, a Radio Network Temporary Identifier (RNTI) for scrambling a Cyclic Redundancy Check (CRC) carried by the first signaling and an RNTI for scrambling a CRC carried by the second signaling are used to determine the target reference signal resource from the first reference signal resource and the second reference signal resource.

2 . The UE according to claim 1 , wherein the transceiver is further configured to receive target data; wherein the maintaining the first timer comprises: as a response to receiving the target data, starting or restarting the first timer; wherein the target data comprises a Medium Access Control (MAC) Service Data Unit (SDU) from a Dedicated Traffic Channel (DTCH), or a Dedicated Control Channel (DCCH) or a Common Control Channel (CCCH).

3 . The UE according to claim 1 , wherein the transceiver is further configured to monitor a second message in a first time window; and determine whether to enter into an RRC idle state according to whether the second message is detected; wherein an expiration of the first timer is used to trigger a transmission of the first message; wherein a time of transmitting the first message is used to determine the first time window; and wherein the determining whether to enter into an RRC idle state according to whether the second message is detected comprises: not entering the RRC idle state when the second message is detected, or entering the RRC idle state when the second message is not detected.

4 . The UE according to claim 1 , wherein the transceiver is further configured to switch from a first Bandwidth Part (BWP) to a second BWP; wherein maintaining a first timer comprises: as a response to switching from the first BWP to the second BWP, starting or continuing the first timer.

5 . The UE according to claim 4 , wherein the transceiver is further configured to monitor a third message in a first time window; and determine whether to be camped on the second BWP according to whether the third message is detected; wherein an expiration of the first timer is used to trigger a transmission of the first message; wherein a time of transmitting the first message is used to determine the first time window; and wherein determining whether to be camped on the second BWP according to whether the third message is detected comprises: not being camped on the second BWP when the third message is detected, or being camped on the second BWP when the third message is detected.

6 . The UE according to claim 1 , wherein frequency-domain resources occupied by the first signal is a first subcarrier set, while frequency-domain resources occupied by the second signal is a second subcarrier set, wherein the first subcarrier set and the second subcarrier set belonging to a target Bandwidth Part (BWP), and wherein the first subcarrier set being orthogonal with the second subcarrier set in frequency domain.

7 . The UE according to claim 1 , wherein both frequency-domain resources occupied by the first signaling and frequency-domain resources occupied by the second signaling belong to a target control resource set associated with a first-type reference signal resource set and a second-type reference signal resource set; wherein the first field of the first signaling is used to indicate the first reference signal resource in the first-type reference signal resource set; and wherein the second field of the second signaling is used to indicate the second reference signal resource in the second-type reference signal resource set.

8 . The UE according to claim 1 , wherein frequency-domain resources occupied by the first signaling and frequency-domain resources occupied by the second signaling respectively belong to a first control resource set and a second control resource set, wherein overlapping frequency-domain resources exist between frequency-domain resources occupied by the first control resource set and frequency-domain resources occupied by the second control resource set; wherein a search space set associated with the first control resource set is associated with the first identifier, while a search space set associated with the second control resource set is not associated with the first identifier; and wherein a DMRS of a control signaling in the second control resource set and a DMRS of a control signaling in the first control resource set are Quasi Co-located (QCL).

9 . A method for a user equipment (UE) in wireless communications, method comprising:

maintaining a first timer;

transmitting a first message, as a response to any condition in a first condition set being satisfied, wherein a condition in the first condition set is that the first timer is expired, wherein the first message is used for indicating at least one non-unicast identifier; wherein the first node is in a first radio resource control (RRC) state when transmitting the first message; wherein the first RRC state is an RRC connected state or an RRC inactive state; and

receiving a first signaling, a second signaling, a first signal and a second signal;

wherein the first signaling is used to determine at least one of time-domain resources or frequency-domain resources occupied by the first signal, while the second signaling is used to determine at least one of time-domain resources or frequency-domain resources occupied by the second signal; wherein overlapping time-domain resources exist between the time-domain resources occupied by the first signal and the time-domain resources occupied by the second signal; wherein the first signaling comprises a first field used to indicate a first reference signal resource and the second signaling comprises a second field used to indicate a second reference signal resource different from the first reference signal resource; wherein a demodulation reference signal (DMRS) of a channel occupied by the first signal is Quasi Co-located (QCL) with a target reference signal resource and a DMRS of a channel occupied by the second signal is QCL with the target reference signal resource; wherein the target reference signal resource is one of the first reference signal resource or the second reference signal resource; and wherein a priority of the first signal and a priority of the second signal are used to determine the target reference signal resource from the first reference signal resource and the second reference signal resource, or, a Radio Network Temporary Identifier (RNTI) for scrambling a Cyclic Redundancy Check (CRC) carried by the first signaling and an RNTI for scrambling a CRC carried by the second signaling are used to determine the target reference signal resource from the first reference signal resource and the second reference signal resource.

10 . The method according to claim 9 , further comprising:

receiving target data; wherein maintaining the first timer comprises: as a response to receiving the target data, starting or restarting the first timer; wherein the target data comprises a Medium Access Control (MAC) Service Data Unit (SDU) from a Dedicated Traffic Channel (DTCH), or a Dedicated Control Channel (DCCH) or a Common Control Channel (CCCH).

11 . The method according to claim 9 , further comprising:

monitoring a second message in a first time window; and

determining whether to enter into an RRC idle state according to whether the second message is detected; wherein an expiration of the first timer is used to trigger a transmission of the first message; wherein a time of transmitting the first message is used to determine the first time window; and wherein determining whether to enter into an RRC idle state according to whether the second message is detected comprises: not entering the RRC idle state when the second message is detected, or entering the RRC idle state when the second message is not detected.

12 . The method according to claim 9 , further comprises:

switching from a first Bandwidth Part (BWP) to a second BWP; wherein maintaining a first timer comprises: as a response to switching from the first BWP to the second BWP, starting or continuing the first timer.

13 . The method according to claim 12 , further comprising:

monitoring for a third message in a first time window; and

determining whether to be camped on the second BWP according to whether the third message is detected; wherein an expiration of the first timer is used to trigger a transmission of the first message; wherein a time of transmitting the first message is used to determine the first time window; and wherein determining whether to be camped on the second BWP according to whether the third message is detected comprises: not being camped on the second BWP when the third message is detected, or being camped on the second BWP when the third message is detected.

14 . The method according to claim 9 , wherein frequency-domain resources occupied by the first signal is a first subcarrier set, while frequency-domain resources occupied by the second signal is a second subcarrier set, wherein the first subcarrier set and the second subcarrier set belonging to a target Bandwidth Part (BWP), and wherein the first subcarrier set being orthogonal with the second subcarrier set in frequency domain.

15 . The method according to claim 9 , wherein both frequency-domain resources occupied by the first signaling and frequency-domain resources occupied by the second signaling belong to a target control resource set associated with a first-type reference signal resource set and a second-type reference signal resource set; wherein the first field of the first signaling is used to indicate the first reference signal resource in the first-type reference signal resource set; and wherein the second field of the second signaling is used to indicate the second reference signal resource in the second-type reference signal resource set.

16 . The method according to claim 9 , wherein frequency-domain resources occupied by the first signaling and frequency-domain resources occupied by the second signaling respectively belong to a first control resource set and a second control resource set, wherein overlapping frequency-domain resources exist between frequency-domain resources occupied by the first control resource set and frequency-domain resources occupied by the second control resource set; wherein a search space set associated with the first control resource set is associated with the first identifier, while a search space set associated with the second control resource set is not associated with the first identifier; and wherein a DMRS of a control signaling in the second control resource set and a DMRS of a control signaling in the first control resource set are Quasi Co-located (QCL).