Determination of contention resolution timer
Example embodiments of the present disclosure relate to a solution for determining a contention resolution timer. In an aspect, a first device receives, from a second device, an indication to perform Msg3 transmission. The first device transmits, to the second device, information of the first device for contention resolution. In case a configuration of a 4-step random access channel is unavailable in an active bandwidth part for the first device, the first device determines a duration for monitoring a contention resolution message based on one of: a first configuration of a 2-step random access channel in the active bandwidth part, or a second configuration of a 4-step random access channel in a bandwidth part different from the active bandwidth part. Example embodiments of the present disclosure can improve the performance of a random access procedure.
1. A first device comprising:
at least one processor; and
at least one memory storing instructions that, when executed with the at least one processor, cause the first device at least to:
transmit, to a second device, at least one message according to a first configuration of a 2-step random access channel in an active bandwidth part;
receive, from the second device in response to the at least one message, an indication to perform Msg3 transmission;
transmit, to the second device via Msg3, information of the first device for contention resolution;
based on a determination that a configuration of a 4-step random access channel is not configured in the active bandwidth part for the first device, determine a duration for monitoring for a contention resolution message based on one of:
the first configuration of the 2-step random access channel in the active bandwidth part, or
a second configuration of a 4-step random access channel in a bandwidth part that is different from the active bandwidth part; and
based on a determination that the first configuration indicates a contention resolution timer, determine the duration as a time length of the contention resolution timer,
wherein the first configuration indicates the contention resolution timer when the configuration of the 4-step random access channel is not configured in the active bandwidth part for the first device, and does not indicate the contention resolution timer when the configuration of the 4-step random access channel is configured in the active bandwidth part for the first device.
2. The first device of claim 1 , wherein the at least one memory stores instructions that, when executed with the at least one processor, cause the first device to:
based on a determination that the first configuration does not indicate the contention resolution timer, determine the duration as a time length of a contention resolution timer indicated in the second configuration.
3. The first device of claim 1 , wherein the active bandwidth part comprises one of the following:
an initial bandwidth part for the first device,
a default bandwidth part for the first device,
a first active bandwidth part for the first device, or
a predetermined bandwidth part indicated by the second device.
4. The first device of claim 1 , wherein the at least one memory stores instructions that, when executed with the at least one processor, cause the first device to:
based on a determination that the first configuration does not indicate the contention resolution timer, determine the duration as a time length for monitoring a MSGB from the second device, wherein the MSGB comprises a message transmitted by the second device in response to a MSGA transmitted over the 2-step random access channel, wherein the at least one message comprises, at least, the MSGA.
5. The first device of claim 4 , wherein the time length for monitoring the MSGB is a time length of an MSGB response window.
6. The first device of claim 1 , wherein the at least one memory stores instructions that, when executed with the at least one processor, cause the first device to:
receive the first configuration or the second configuration from the second device.
7. The first device of claim 1 , wherein the first device comprises a terminal device, and the second device comprises a network device.
8. The first device of claim 1 , wherein the contention resolution message comprises a contention resolution message in response to the information of the first device transmitted via Msg3, wherein the at least one memory stores instructions that, when executed with the at least one processor, cause the first device to:
monitor for the contention resolution message, in the active bandwidth part and according to the first configuration, for the determined duration.
9. A second device comprising:
at least one processor; and
at least one memory storing instructions that, when executed with the at least one processor, cause the second device to:
receive, from a first device, at least one message according to a first configuration of a 2-step random access channel in an active bandwidth part;
transmit, to the first device in response to the at least one message, an indication to perform Msg3 transmission;
based on a determination that a configuration of a 4-step random access channel is not configured in the active bandwidth part for the first device, determine a duration for transmitting a contention resolution message to the first device based on one of:
the first configuration of the 2-step random access channel in the active bandwidth part, or
a second configuration of a 4-step random access channel in a bandwidth part that is different from the active bandwidth part;
based on a determination that the first configuration indicates the contention resolution timer, determine the duration as a time length of the contention resolution timer; and
based on a determination that information of the first device for contention resolution is received from the first device via Msg3, transmit the contention resolution message to the first device within the duration,
wherein the first configuration indicates the contention resolution timer when the configuration of the 4-step random access channel is not configured in the active bandwidth part for the first device, and does not indicate the contention resolution timer when the configuration of the 4-step random access channel is configured in the active bandwidth part for the first device.
10. The second device of claim 9 , wherein the at least one memory stores instructions that, when executed with the at least one processor, cause the second device to:
based on a determination the first configuration does not indicate the contention resolution timer, determine the duration as a time length of a contention resolution timer indicated in the second configuration.
11. The second device of claim 9 , wherein the active bandwidth part comprises one of the following:
an initial bandwidth part for the first device,
a default bandwidth part for the first device,
a first active bandwidth part for the first device, or
a predetermined bandwidth part indicated by the second device.
12. The second device of claim 9 , wherein the at least one memory stores instructions that, when executed with the at least one processor, cause the second device to:
based on a determination that the first configuration does not indicate the contention resolution timer, determine the duration as a time length for the first device to monitor a MSGB from the second device, wherein the MSGB comprises a message transmitted by the second device in response to a MSGA transmitted over the 2-step random access channel, wherein the at least one message comprises, at least, the MSGA.
13. The second device of claim 12 , wherein the time length for monitoring the MSGB is a time length of an MSGB response window.
14. The second device of claim 9 , wherein the at least one memory stores instructions that, when executed with the at least one processor, cause the second device to:
determine the first configuration or the second configuration; and
transmit the first configuration or the second configuration to the first device.
15. The second device of claim 14 , wherein the at least one memory stores instructions that, when executed with the at least one processor, cause the second device to:
based on a determination that the configuration of the 4-step random access channel is not configured in the active bandwidth part, cause the first configuration to indicate the contention resolution timer for the active bandwidth part.
16. The second device of claim 14 , wherein the at least one memory stores instructions that, when executed with the at least one processor, cause the second device to:
cause the first configuration to indicate the contention resolution timer for the active bandwidth part.
17. The second device of claim 9 , wherein the first device comprises a terminal device, and the second device comprises a network device.
18. A method comprising:
transmitting, with a first device to a second device, at least one message according to a first configuration of a 2-step random access channel in an active bandwidth part;
receiving, from the second device in response to the at least one message, an indication to perform Msg3 transmission;
transmitting, to the second device via Msg3, information of the first device for contention resolution; and
based on a determination that a configuration of a 4-step random access channel is not configured in the active bandwidth part for the first device, determining a duration for monitoring for a contention resolution message based on one of:
the first configuration of the 2-step random access channel in the active bandwidth part, or
a second configuration of a 4-step random access channel in a bandwidth part that is different from the active bandwidth part; and
based on a determination that the first configuration indicates a contention resolution timer, determining the duration as a time length of the contention resolution timer,
wherein the first configuration indicates the contention resolution timer when the configuration of the 4-step random access channel is not configured in the active bandwidth part for the first device, and does not indicate the contention resolution timer when the configuration of the 4-step random access channel is configured in the active bandwidth part for the first device.