Bandwidth part configuration based on a clear channel assessment
Apparatuses, methods, and systems are disclosed for bandwidth part (“BWP”) configuration based on a clear channel assessment (“CCA”). One method includes configuring at least one BWP. Each BWP of the at least one BWP comprises a downlink BWP and an uplink BWP. The method includes indicating a first BWP of the at least one BWP as an active BWP. The method includes performing a CCA prior to transmitting a message. The method includes, in response to the CCA being successful for the active BWP, transmitting the message using the active BWP. The method includes, in response to the CCA being unsuccessful for the active BWP and the CCA being successful for only a second BWP of the at least one BWP: indicating the second BWP as the active BWP; and transmitting the message using the active BWP.
1. A method comprising:
configuring at least one bandwidth part, wherein each bandwidth part of the at least one bandwidth part comprises a downlink bandwidth part and an uplink bandwidth part;
indicating a first bandwidth part of the at least one bandwidth part as an active bandwidth part;
performing a clear channel assessment on the active bandwidth part prior to transmitting a message;
in response to the clear channel assessment being successful for the active bandwidth part, transmitting the message using the active bandwidth part; and
in response to the clear channel assessment being unsuccessful for the active bandwidth part:
performing a clear channel assessment on a plurality of bandwidth parts of the at least one bandwidth part other than the active bandwidth part; and
in response to the clear channel assessment being successful for only a second bandwidth part of the plurality of bandwidth parts on which the clear channel assessment is performed:
indicating the second bandwidth part as the active bandwidth part; and
transmitting the message using the active bandwidth part.
2. The method of claim 1 , further comprising, in response to the clear channel assessment being unsuccessful for the active bandwidth part and the clear channel assessment being successful for a plurality of bandwidth parts of the at least one bandwidth part:
selecting a third bandwidth part of the plurality of bandwidth parts as the active bandwidth part; and
transmitting the message using the active bandwidth part.
3. The method of claim 2 , wherein selecting the third bandwidth part as the active bandwidth part comprises randomly selecting a bandwidth part of the plurality of bandwidth parts as the active bandwidth part.
4. The method of claim 2 , wherein selecting the third bandwidth part as the active bandwidth part comprises selecting a bandwidth part of the plurality of bandwidth parts having a lowest required transmission power.
5. The method of claim 1 , wherein the message comprises a random access procedure message 1.
6. The method of claim 1 , wherein each bandwidth part of the at least one bandwidth part comprises the downlink bandwidth part and a plurality of uplink bandwidth parts.
7. The method of claim 1 , wherein the active bandwidth part comprises the downlink bandwidth part and a plurality of uplink bandwidth parts.
8. The method of claim 1 , further comprising receiving information indicating a random access channel preamble to transmit in the message.
9. The method of claim 1 , further comprising receiving information indicating a set of bandwidth parts of the at least one bandwidth part for performing the clear channel assessment.
10. The method of claim 9 , wherein the information comprises a bitmap with each bit of the bitmap corresponding to a bandwidth part of the set of bandwidth parts.
11. The method of claim 1 , further comprising receiving a response to transmission of the message.
12. The method of claim 11 , wherein the response is received on a linked downlink bandwidth part corresponding to the active bandwidth part.
13. The method of claim 11 , wherein the response is received on one of a plurality of linked downlink bandwidth parts corresponding to the active bandwidth part.
14. The method of claim 11 , wherein the response comprises one or more grants for a plurality of uplink bandwidth parts to transmit a random access channel message 3.
15. An apparatus comprising:
a processor that:
configures at least one bandwidth part, wherein each bandwidth part of the at least one bandwidth part comprises a downlink bandwidth part and an uplink bandwidth part;
indicates a first bandwidth part of the at least one bandwidth part as an active bandwidth part; and
performs a clear channel assessment on the active bandwidth part prior to transmitting a message;
a transmitter that, in response to the clear channel assessment being successful for the active bandwidth part, transmits the message using the active bandwidth part;
wherein, in response to the clear channel assessment being unsuccessful for the active bandwidth part:
the processor performs a clear channel assessment on a plurality of bandwidth parts of the at least one bandwidth part other than the active bandwidth part; and
in response to the clear channel assessment being successful for only a second bandwidth part of the plurality of bandwidth parts on which the clear channel assessment is performed:
the processor indicates the second bandwidth part as the active bandwidth part; and
the transmitter transmits the message using the active bandwidth part.
16. The apparatus of claim 15 , wherein the processor selects a third bandwidth part as the active bandwidth part by randomly selecting a bandwidth part of the plurality of bandwidth parts as the active bandwidth part.
17. The apparatus of claim 15 , wherein the processor selects a third bandwidth part as the active bandwidth part by selecting a bandwidth part of the plurality of bandwidth parts having a lowest required transmission power.
18. The apparatus of claim 15 , further comprising a receiver that receives information indicating a random access channel preamble to transmit in the message.
19. The apparatus of claim 15 , further comprising a receiver that receives information indicating a set of bandwidth parts of the at least one bandwidth part for performing the clear channel assessment.
20. The apparatus of claim 15 , further comprising a receiver that receives a response to transmission of the message.