Sidelink capability signaling and configuration

1. A method of wireless communication at a user equipment (UE), comprising:

transmitting a capability indication message to a network entity, the capability indication message comprising a first sidelink capability for direct communication between the UE and one or more secondary UEs;

receiving a configuration message from the network entity in response to the capability indication message, wherein the configuration message includes one or more configuration parameters of one or more bandwidth parts (BWPs) based on the first sidelink capability for sidelink communications between the UE and the one or more secondary UEs;

establishing a communication link based on the one or more configuration parameters received in response to the configuration message;

determining a change in capability from the first sidelink capability to a second sidelink capability subsequent to establishing the communication link, wherein the second sidelink capability is different from the first sidelink capability;

transmitting the second sidelink capability to the network entity or the one or more secondary UEs subsequent to determining the change in capability; and

continuing communications on the communication link based on the second sidelink capability subsequent to transmitting the second sidelink capability to the network entity or the one or more secondary UEs.

2. The method of claim 1 , further comprising determining a capability value associated with the configuration message, the capability value indicating one or more enabled configurations corresponding to the first sidelink capability, wherein establishing the communication link is further based on the one or more enabled configurations.

3. The method of claim 1 , wherein transmitting the capability indication message comprising the first sidelink capability comprises transmitting a sidelink duplexing mode capability;

wherein establishing the communication link between the UE and the one or more secondary UEs further comprises operating, by the UE, in a duplexing mode corresponding to the first sidelink duplexing mode capability.

4. The method of claim 3 , wherein transmitting the sidelink duplexing mode capability comprises transmitting one or any combination of:

a half duplex mode capability of communication between an access link with the network entity and a sidelink with a respective secondary UE;

a transmit multiplex mode capability of being able to transmit to one or more network entities using one or more access links while concurrently being able to transmit to one or multiple ones of the one or more secondary UEs using a respective sidelink or respective multiple sidelinks;

a receive multiplex mode capability of being able to receive from the one or more network entities using the one or more access links while concurrently being able to receive from the one or the multiple ones of the one or more secondary UEs using the respective sidelink or the respective multiple sidelinks;

a transmit full-duplex mode capability of being able to transmit to a first node while concurrently being able to receive from a second node; and

a receive full-duplex mode capability of being able to receive from the first node while concurrently being able to transmit to the second node.

5. The method of claim 4 , wherein each of the transmit multiplex mode capability, the receive multiplex mode capability, the transmit full-duplex mode capability, and the receive full-duplex mode capability correspond to at least one of a spatial division multiplexing (SDM), frequency division multiplexing (FDM), or a combination thereof.

6. The method of claim 4 , wherein each of the first node and the second node correspond to at least one of a UE, network entity, or combination thereof.

7. The method of claim 4 , wherein the first node is the same as the second node.

8. The method of claim 4 , wherein the first node differs from the second node.

9. The method of claim 1 , wherein transmitting the capability indication message comprising the first sidelink capability comprises transmitting a number of antenna panels, wherein a sidelink duplexing mode capability corresponds to the number of antenna panels.

10. The method of claim 1 , wherein the first sidelink capability uses a first bandwidth part, and wherein the second sidelink capability uses a second bandwidth part different from the first bandwidth part.

11. The method of claim 1 , wherein receiving the configuration message comprises receiving a first bandwidth part identification associated with use of the first sidelink capability and a second bandwidth part identification associated with use of a second sidelink capability, wherein the first bandwidth part identification corresponds to a first bandwidth part that is different from the second bandwidth part identification that corresponds to a second bandwidth part; and

wherein establishing the communication link comprises:

communicating using the first bandwidth part based on the first sidelink capability; and

communicating using the second bandwidth part based on the second sidelink capability.

12. The method of claim 1 , wherein transmitting the capability indication message comprising the first sidelink capability comprises transmitting a half duplex mode capability, and

wherein establishing the communication link further comprises operating, by the UE, in a half duplex mode between an access link with a network entity and a sidelink with a respective secondary UE.

13. The method of claim 1 , wherein transmitting the capability indication message comprising the first sidelink capability comprises transmitting a transmit multiplex mode capability, and

wherein establishing the communication link further comprises operating, by the UE, in a transmit multiplex mode for transmitting to one or more network entities using one or more access links while concurrently being able to transmit to one or multiple ones of the secondary UEs using a respective sidelink or respective multiple sidelinks.

14. The method of claim 1 , wherein transmitting the capability indication message comprising the first sidelink capability comprises transmitting a receive multiplex mode capability, and

wherein establishing the communication link further comprises operating, by the UE, in a receive multiplex mode for receiving from one or more network entities using one or more access links while concurrently being able to receive from one or multiple ones of the secondary UEs using a respective sidelink or respective multiple sidelinks.

15. The method of claim 1 , wherein transmitting the capability indication message comprising the first sidelink capability comprises transmitting a transmit full-duplex mode capability, and

wherein establishing the communication link further comprises transmitting, by the UE, to one or more network entities using one or more access link while concurrently being able to receive from one or multiple ones of secondary UEs using a respective sidelink or respective multiple sidelinks.

16. The method of claim 1 , wherein transmitting the capability indication message comprising the first sidelink capability comprises transmitting a receive full-duplex mode capability, and

wherein establishing the communication link further comprises receiving, by the UE, from one or more network entities using one or more access links while concurrently being able to transmit to the one or the multiple ones of the one or more secondary UEs using a respective sidelink or respective multiple sidelinks.

17. The method of claim 1 , wherein transmitting the capability indication message to the network entity further comprises transmitting to a base station via an access link between the UE and the base station, wherein the base station is configured to operate as a negotiating entity of sidelink connections by relaying at least a subset of the capability indication message to the one or more secondary UEs.

18. The method of claim 1 , wherein transmitting the capability indication message to the network entity further comprises transmitting to the one or more secondary UEs via a sidelink between the UE and the one or more secondary UEs.

19. The method of claim 1 , wherein transmitting the capability indication message further comprises transmitting in at least one of a Radio Resource Control (RRC) message, media access control (MAC) control element (CE), downlink control information (DCI), sidelink control information (SCI), or combination thereof.

20. The method of claim 1 , wherein the network entity corresponds to a base station or a sidelink UE.

21. The method of claim 1 , wherein the first sidelink capability is associated with a first bandwidth part, and wherein the second sidelink capability is associated with a second bandwidth part different from the first bandwidth part.

22. The method of claim 1 , further comprising transmitting a second capability indication message to the network entity comprising the second sidelink capability based on determining the change in capability from the first sidelink capability.

23. An apparatus for wireless communication at a user equipment(UE), comprising:

a transceiver;

a memory configured to store instructions; and

one or more processors coupled with the transceiver and the memory, wherein the one or more processors are configured to execute the instructions to:

transmit a capability indication message to a network entity, the capability indication message comprising a first sidelink capability for direct communication between the UE and one or more secondary UEs;

receive a configuration message from the network entity in response to the capability indication message, wherein the configuration message includes one or more configuration parameters of one or more bandwidth parts (BWPs) based on the first sidelink capability for sidelink communications between the UE and the one or more secondary UEs;

establish a communication link based on the one or more configuration parameters received in response to the configuration message;

determine a change in capability from the first sidelink capability to a second sidelink capability subsequent to establishing the communication link, wherein the second sidelink capability is different from the first sidelink capability;

transmitting the second sidelink capability to the network entity or the one or more secondary UEs subsequent to determining the change in capability; and

continuing communications on the communication link based on the second sidelink capability subsequent to transmitting the second sidelink capability to the network entity or the one or more secondary UEs.

24. A method of wireless communication at a network entity, comprising:

receiving a capability indication message from a user equipment (UE), the capability indication message comprising a first sidelink capability for direct communication between the UE and one or more secondary UEs;

transmitting a configuration message to the UE in response to the capability indication message, wherein the configuration message includes one or more configuration parameters of one or more bandwidth parts (BWPs) based on the first sidelink capability for sidelink communications between the UE and the one or more secondary UEs;

establishing a communication link based on the one or more configuration parameters in response to transmitting the configuration message;

determining a change in capability from the first sidelink capability to a second sidelink capability subsequent to establishing the communication link, wherein the second sidelink capability is different from the first sidelink capability; and

receiving the second sidelink capability from the UE subsequent to determining the change in capability.

25. The method of claim 24 , wherein receiving the capability indication message comprising the first sidelink capability comprises receiving a sidelink duplexing mode capability;

wherein establishing the communication link further comprises operating, by the network entity, in a duplexing mode corresponding to the sidelink duplexing mode capability.

26. The method of claim 25 , wherein receiving the sidelink duplexing mode capability comprises receiving one or any combination of:

a half duplex mode capability of communication between an access link with the network entity and a sidelink with a respective secondary UE;

a transmit multiplex mode capability of being able to transmit to one or more network entities using one or more access links while concurrently being able to transmit to one or multiple ones of the secondary UEs using a respective sidelink or respective multiple sidelinks;

a receive multiplex mode capability of being able to receive from the one or more network entities using the one or more access links while concurrently being able to receive from the one or the multiple ones of the secondary UEs using the respective sidelink or the respective multiple sidelinks;

a transmit full-duplex mode capability of being able to transmit to a first node while concurrently being able to receive from a second node; and

a receive full-duplex mode capability of being able to receive from the first node while concurrently being able to transmit to the second node.

27. The method of claim 24 , wherein receiving the capability indication message comprising the first sidelink capability comprises receiving a number of antenna panels, wherein a sidelink duplexing mode capability corresponds to the number of antenna panels.

28. The method of claim 24 , further comprising transmitting, by the network entity, the capability indication message to the one or more secondary UEs using a respective sidelink or respective multiple sidelinks.

29. The method of claim 24 , wherein receiving the capability indication message further comprises receiving in an Radio Resource Control (RRC) message.

30. An apparatus for wireless communication at a network entity, comprising:

a transceiver;

a memory configured to store instructions; and

one or more processors coupled with the transceiver and the memory, wherein the one or more processors are configured to execute the instructions to:

receive a capability indication message from a user equipment (UE), the capability indication message comprising a first sidelink capability for direct communication between the UE and one or more secondary UEs;

transmit a configuration message to the UE in response to the capability indication message, wherein the configuration message includes one or more configuration parameters of one or more bandwidth parts (BWPs) based on the first sidelink capability for sidelink communications between the UE and the one or more secondary UEs;

establish a communication link based on the one or more configuration parameters in response to transmitting the configuration message;

determine a change in capability from the first sidelink capability to a second sidelink capability subsequent to establishing the communication link, wherein the second sidelink capability is different from the first sidelink capability; and

receiving the second sidelink capability from the UE subsequent to determining the change in capability.