System and method for beam switching and reporting
A user equipment (UE) may be configured to perform a random access channel (RACH) procedure with a base station. As part of the RACH procedure, the base station may transmit a contention resolution message to the UE. The UE may receive, from the base station, the contention resolution message. The contention resolution message may indicate at least a beam index corresponding to a beam, such as a transmit beam of the base station. The UE may determine whether the beam index is applicable to the UE. The UE may communicate with the base station through the beam corresponding to the beam index when the beam index is applicable to the UE. For example, the UE may send an acknowledgement message to the base station, and the base station and UE may switch to a beam corresponding to the beam index after communication of the acknowledgement message.
1. A method of wireless communication by a user equipment (UE), comprising:
receiving, after receiving a random access response for a random access channel (RACH) procedure with a base station, a contention resolution message for the RACH procedure, the contention resolution message including information indicating at least a beam index corresponding to a beam;
determining whether the beam index is applicable to the UE; and
communicating with the base station through the beam corresponding to the beam index when the beam index is applicable to the UE.
2. The method of claim 1 , further comprising:
transmitting, to the base station, an acknowledgement message when the beam index is determined to be applicable to the UE.
3. The method of claim 1 , wherein the contention resolution message is associated with a random access procedure.
4. The method of claim 1 , wherein the determining whether the beam index is applicable to the UE comprises:
attempting to decode the contention resolution message based on a radio network temporary identifier (RNTI) associated with the UE,
wherein the beam index is determined to be applicable to the UE when the contention resolution message is successfully decoded.
5. The method of claim 1 , further comprising:
refraining from transmitting a non-acknowledgement message to the base station when the beam index is determined to be inapplicable to the UE or if the contention resolution message is unsuccessfully decoded.
6. The method of claim 1 , wherein the contention resolution message further includes an indication of one or more channels associated with the beam index, and the communication with the base station through the beam corresponding to the beam index is performed on the one or more indicated channels.
7. The method of claim 1 , further comprising;
transmitting, to the base station, a random access preamble;
receiving, from the base station, the random access response based on the random access preamble; and
transmitting, to the base station, a connection request message based on the random access response,
wherein the contention resolution message is received based on the connection request message.
8. A method of wireless communication by a base station, comprising:
transmitting, after transmitting a random access response for a random access channel (RACH) procedure with a user equipment (UE), a contention resolution message for the RACH procedure, the contention resolution message including information indicating at least a beam index corresponding to a beam and the contention resolution message indicating that the beam index is applicable to the UE;
determining whether an acknowledgement message is received from the UE in response to the contention resolution message; and
communicating with the UE through the beam corresponding to the beam index when the acknowledgement message is determined to be received from the UE.
9. The method of claim 8 , wherein the contention resolution message is associated with a random access procedure.
10. The method of claim 9 , further comprising:
scrambling at least a portion of the contention resolution message using a radio network temporary identifier (RNTI) associated the UE.
11. The method of claim 8 , wherein the contention resolution message further includes an indication of one or more channels associated with the beam index, and the communication with the UE through the beam corresponding to the beam index is performed on the one or more indicated channels.
12. The method of claim 8 , further comprising:
communicating with the UE through a serving beam before transmission of the contention resolution message,
wherein the communication with the UE continues through the serving beam based on an absence of an acknowledgement message from the UE.
13. The method of claim 8 , further comprising:
receiving, from the UE, a random access preamble;
transmitting, to the UE, the random access response based on the random access preamble; and
receiving, from the UE, a connection request message based on the random access response,
wherein the contention resolution message is transmitted based on the connection request message.
14. An apparatus for wireless communication, the apparatus comprising:
means for receiving, after receiving a random access response for a random access channel (RACH) procedure with a base station, a contention resolution message for the RACH procedure, the contention resolution message including information indicating at least a beam index corresponding to a beam;
means for determining whether the beam index is applicable to the apparatus; and
means for communicating with the base station through the beam corresponding to the beam index when the beam index is applicable to the apparatus.
15. The apparatus of claim 14 , further comprising:
means for transmitting, to the base station, an acknowledgement message when the beam index is determined to be applicable to the apparatus.
16. The apparatus of claim 14 , wherein the contention resolution message is associated with a random access procedure.
17. The apparatus of claim 14 , wherein the means for determining whether the beam index is applicable to the apparatus is configured to:
attempt to decode the contention resolution message based on a radio network temporary identifier (RNTI) associated with the apparatus,
wherein the beam index is determined to be applicable to the apparatus when the contention resolution message is successfully decoded.
18. The apparatus of claim 14 , further comprising:
means for refraining from transmitting a non-acknowledgement message to the base station when the beam index is determined to be inapplicable to the apparatus or if the contention resolution message is unsuccessfully decoded.
19. The apparatus of claim 14 , wherein the contention resolution message further includes an indication of one or more channels associated with the beam index, and the communication with the base station through the beam corresponding to the beam index is performed on the one or more indicated channels.
20. The apparatus of claim 14 , further comprising;
means for transmitting, to the base station, a random access preamble;
means for receiving, from the base station, the random access response based on the random access preamble; and
means for transmitting, to the base station, a connection request message based on the random access response,
wherein the contention resolution message is received based on the connection request message.
21. An apparatus for wireless communication, the apparatus comprising:
means for transmitting, after transmitting a random access response for a random access channel (RACH) procedure with a user equipment (UE), a contention resolution message for the RACH procedure, the contention resolution message including information indicating at least a beam index corresponding to a beam and the contention resolution message indicating that the beam index is applicable to the UE;
means for determining whether an acknowledgement message is received from the UE in response to the contention resolution message; and
means for communicating with the UE through the beam corresponding to the beam index when the acknowledgement message is determined to be received from the UE.
22. The apparatus of claim 21 , wherein the contention resolution message is associated with a random access procedure.
23. The apparatus of claim 22 , further comprising:
means for scrambling at least a portion of the contention resolution message using a radio network temporary identifier (RNTI) associated the UE.
24. The apparatus of claim 21 , wherein the contention resolution message further includes an indication of one or more channels associated with the beam index, and the communication with the UE through the beam corresponding to the beam index is performed on the one or more indicated channels.
25. The apparatus of claim 21 , further comprising:
means for communicating with the UE through a serving beam before transmission of the contention resolution message,
wherein the communication with the UE continues through the serving beam based on an absence of an acknowledgement message from the UE.
26. The apparatus of claim 21 , further comprising:
means for receiving, from the UE, a random access preamble;
means for transmitting, to the UE, the random access response based on the random access preamble; and
means for receiving, from the UE, a connection request message based on the random access response,
wherein the contention resolution message is transmitted based on the connection request message.
27. An apparatus for wireless communication, the apparatus comprising:
a memory; and
at least one processor coupled to the memory and configured to:
receive, after reception of a random access response for a random access channel (RACH) procedure with a base station, a contention resolution message for the RACH procedure, the contention resolution message including information indicating at least a beam index corresponding to a beam;
determine whether the beam index is applicable to the apparatus; and
communicating with the base station through the beam corresponding to the beam index when the beam index is applicable to the apparatus.
28. The apparatus of claim 27 , wherein the at least one processor is further configured to:
transmit, to the base station, an acknowledgement message when the beam index is determined to be applicable to the apparatus.
29. An apparatus for wireless communication, the apparatus comprising:
a memory; and
at least one processor coupled to the memory and configured to:
transmit, after transmission of a random access response for a random access channel (RACH) procedure with a user equipment (UE), a contention resolution message for the RACH procedure, the contention resolution message including information indicating at least a beam index corresponding to a beam and the contention resolution message indicating that the beam index is applicable to the UE;
determine whether an acknowledgement message is received from the UE in response to the contention resolution message; and
communicate with the UE through the beam corresponding to the beam index when the acknowledgement message is determined to be received from the UE.