Techniques and apparatuses for random access procedure in a wireless backhaul network
Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may transmit beam information associated with a set of cells detected by the base station, wherein the beam information is transmitted to a target base station; and receive, based at least in part on transmitting the beam information to the target base station, one or more random access messages, wherein the one or more random access messages are transmitted by one or more other base stations, wherein the one or more other base stations are associated with one or more cells included in the set of cells detected by the base station. Numerous other aspects are provided.
1. A method of wireless communication, comprising:
receiving, by a base station, one or more parameters associated with a target base station, of a plurality of possible target base stations, for initiating a backhaul connection, wherein the target base station is deployed within a wireless backhaul network, wherein the one or more parameters include a random access channel (RACH) configuration period for the wireless backhaul network and a tone spacing for contention free RACH transmission, wherein the tone spacing for contention free RACH transmissions is different from a tone spacing for contention based RACH transmissions, and wherein the RACH configuration period for the wireless backhaul network is different from a RACH configuration period for an access network;
determining, by the base station, a transmission configuration for a first random access message based at least in part on the one or more parameters associated with the target base station; and
transmitting, by the base station, the first random access message using the transmission configuration.
2. The method of claim 1 , where the base station operates with a user equipment functionality (UEF) and the target base station operates with an access node functionality (ANF).
3. The method of claim 1 , wherein the transmission configuration identifies a particular set of resources to be used for a random access channel transmission by the base station,
wherein the first random access message is transmitted using the particular set of resources, and
wherein a different set of resources is to be used for a transmission by a user equipment,
wherein the different set of resources is different from the particular set of resources.
4. The method of claim 1 , wherein the first random access message indicates at least one of:
a classification of the base station as a base station,
a capability of the base station, or
a configuration for another random access message.
5. The method of claim 1 , wherein the first random access message further relates to at least one of:
a maximum bandwidth,
a downlink-to-uplink switching time, or
a beam correspondence.
6. The method of claim 1 , wherein information associated with the transmission configuration for the first random access message is received by the base station via at least one of:
a master information block, or
a radio resource control message.
7. The method of claim 1 , wherein the transmission configuration identifies a particular set of resources,
wherein the particular set of resources is to be used for a transmission by the base station or for a transmission by a user equipment, and
wherein the first random access message is transmitted using the particular set of resources.
8. The method of claim 7 , wherein the particular set of resources is a set of resources used for contention based random access transmissions.
9. The method of claim 1 , wherein the transmission configuration identifies a particular set of resources,
wherein the particular set of resources is to be used for a transmission by the base station only, and wherein the first random access message is transmitted using the particular set of resources.
10. The method of claim 1 , wherein the transmission configuration identifies a particular power characteristic associated with transmitting the first random access message by the base station.
11. The method of claim 10 , wherein the particular power characteristic is associated with at least one of:
a maximum transmit power associated with transmitting the first random access message,
a power ramping counter associated with a retransmission of the first random access message, or
a beam switching configuration associated with transmitting the first random access message.
12. The method of claim 1 , wherein the transmission configuration identifies a particular channel format associated with transmitting the first random access message by the base station.
13. The method of claim 12 , wherein the particular channel format is associated with at least one of:
a length of a cyclic prefix associated with transmitting the first random access message, or
a bandwidth associated with transmitting the first random access message.
14. The method of claim 1 , wherein beam information, associated with a set of detected cells, is transmitted by the base station.
15. The method of claim 14 , wherein the beam information is transmitted via MSG1 or MSG3.
16. The method of claim 14 , wherein the beam information includes a set of beam identifiers associated with the set of detected cells.
17. The method of claim 14 , wherein a random access response is received from the target base station, and
wherein the beam information is transmitted in another random access message.
18. The method of claim 14 , wherein information that identifies a number of detected cells, for which beam information is to be transmitted by the base station, is received from the target base station via a master information block, remaining minimum system information, a random access response, or a handover message.
19. The method of claim 14 , wherein a different set of random access messages is received based at least in part on the beam information being transmitted by the base station,
wherein the different set of random access messages is received from a set of base stations associated with the set of detected cells.
20. The method of claim 19 , wherein the different set of random access messages includes at least two random access messages,
wherein each of the at least two random access messages is received during a different one of a set of interleaved periods of time.
21. The method of claim 19 , wherein the different set of random access messages includes a single random access message,
wherein the single random access message is received during one of a set of interleaved periods of time.
22. The method of claim 19 , wherein the different set of random access messages is received based at least in part on monitoring a set of interleaved periods of time associated with receiving random access messages,
wherein each of the set of interleaved periods of time is associated with a different cell of the set of detected cells.
23. The method of claim 19 , wherein random access messages, included in the different set of random access messages, are received based at least in part on an index.
24. The method of claim 1 , wherein a duration of the RACH configuration period for the wireless backhaul network is greater than a duration of the RACH configuration period for the access network.
25. The method of claim 1 , wherein the one or more parameters further include a preamble length,
wherein the base station is configured to transmit a preamble for a shorter duration as compared to an access user equipment.
26. The method of claim 25 , wherein a same RACH configuration index is configured for the access user equipment and the base station,
wherein the base station is configured to interpret the RACH configuration index differently as compared to the access user equipment.
27. A base station for wireless communication, comprising:
a memory; and
one or more processors operatively coupled to the memory, the one or more processors configured to:
receive one or more parameters associated with a target base station, of a plurality of possible target base stations, for initiating a backhaul connection, wherein the target base station is deployed within a wireless backhaul network, wherein the one or more parameters include a random access channel (RACH) configuration period for the wireless backhaul network and a tone spacing for contention free RACH transmission, wherein the tone spacing for contention free RACH transmissions is different from a tone spacing for contention based RACH transmissions, and wherein the RACH configuration period for the wireless backhaul network is different from a RACH configuration period for an access network;
determine a transmission configuration for a first random access message based at least in part on the one or more parameters associated with the target base station; and
transmit the first random access message using the transmission configuration.
28. The base station of claim 27 , where the base station operates with a user equipment functionality (UEF) and the target base station operates with an access node functionality (ANF).
29. A non-transitory computer-readable medium storing instructions for wireless communication, the instructions comprising:
one or more instructions that, when executed by one or more processors of a base station, cause the one or more processors to:
receive one or more parameters associated with a target base station, of a plurality of possible target base stations, for initiating a backhaul connection, wherein the target base station is deployed within a wireless backhaul network, wherein the one or more parameters include a random access channel (RACH) configuration period for the wireless backhaul network and a tone spacing for contention free RACH transmission, wherein the tone spacing for contention free RACH transmissions is different from a tone spacing for contention based RACH transmissions, and wherein the RACH configuration period for the wireless backhaul network is different from a RACH configuration period for an access network;
determine a transmission configuration for a first random access message based at least in part on the one or more parameters associated with the target base station; and
transmit the first random access message using the transmission configuration.
30. An apparatus for wireless communication, comprising:
means for receiving one or more parameters associated with a target base station, of a plurality of possible target base stations, for initiating a backhaul connection, wherein the target base station is deployed within a wireless backhaul network, wherein the one or more parameters include a random access channel (RACH) configuration period for the wireless backhaul network and a tone spacing for contention free RACH transmission, wherein the tone spacing for contention free RACH transmissions is different from a tone spacing for contention based RACH transmissions, and wherein the RACH configuration period for the wireless backhaul network is different from a RACH configuration period for an access network;
means for determining a transmission configuration for a first random access message based at least in part on the one or more parameters associated with the target base station; and
means for transmitting the first random access message using the transmission configuration.