Paging for mmW shared radio frequency spectrum bands
Methods, systems, and devices for wireless communication are described. The described techniques provide for transmitting, at a base station, a contention exempt broadcast paging message that includes partial paging information for a user equipment (UE), receiving a random access request message transmitted by a UE in response to the broadcast paging message, and transmitting a unicast paging message which includes complete paging information. The described techniques further provide for determining, at a base station, a first paging opportunity window (POW) and a second POW for a UE, performing a LBT procedure during the first POW, transmitting a broadcast paging message including partial paging information for the UE during the first POW, performing a second LBT procedure during the second POW, transmitting a unicast paging message to the UE during the second POW, the unicast paging message including complete paging information for the UE.
1. A method for wireless communication, comprising:
receiving a contention exempt broadcast paging message comprising partial paging information for a user equipment (UE) over a shared radio frequency spectrum band during a contention exempt transmission (CET) period and concurrent with a reception of a broadcast discovery reference signal (DRS);
transmitting, in response to the received contention exempt broadcast paging message, a random access request message; and
receiving, based on the transmitted random access request, a unicast paging message comprising complete paging information for the UE.
2. The method of claim 1 , wherein:
the contention exempt broadcast paging message is staggered for different UEs across different CET periods.
3. The method of claim 1 , wherein:
the contention exempt broadcast paging message is frequency domain multiplexed with the broadcast DRS.
4. The method of claim 1 , wherein:
receiving the contention exempt broadcast paging message further comprises:
obtaining from the broadcast DRS an indication of a CET random access channel (RACH) location for the UE.
5. The method of claim 1 , wherein:
the partial paging information comprises an indication that the unicast paging message is to be transmitted to the UE.
6. The method of claim 1 , wherein:
the random access request message comprises a CET.
7. The method of claim 1 , wherein:
transmitting the random access request message further comprises: performing a listen before talk (LBT) procedure to gain access to the shared radio frequency spectrum band prior to transmitting the random access request message.
8. The method of claim 7 , wherein:
transmitting the random access request message further comprises: performing the LBT procedure during a contention gap preceding the transmission of the random access request message.
9. The method of claim 1 , wherein:
receiving the unicast paging message further comprises: determining a paging opportunity window (POW) associated with the unicast paging message; and
the method further comprising powering on a receive chain of the UE during the POW.
10. The method of claim 9 , wherein:
the POW comprises multiple transmission time intervals (TTIs).
11. The method of claim 1 , wherein:
the complete paging information comprises an indication of downlink resources associated with a future transmission from a base station to the UE.
12. The method of claim 1 , wherein:
the transmission of the unicast paging message is beam-specific.
13. An apparatus for wireless communication, comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory, wherein the instructions are executable by the processor to:
receive a contention exempt broadcast paging message comprising partial paging information for a user equipment (UE) over a shared radio frequency spectrum band concurrent with a reception of a broadcast discovery reference signal (DRS);
transmit, in response to the received contention exempt broadcast paging message, a random access request message; and
receive, based on the transmitted random access request, a unicast paging message comprising complete paging information for the UE.
14. The apparatus of claim 13 , wherein:
the contention exempt broadcast paging message is staggered for different UEs across different CET periods.
15. The apparatus of claim 13 , wherein:
the contention exempt broadcast paging message is frequency domain multiplexed with the broadcast DRS.
16. The apparatus of claim 13 , wherein the instructions executable by the processor to receive the contention exempt broadcast paging message comprise instructions executable by the processor to:
obtain from the broadcast DRS an indication of a CET random access channel (RACH) location for the UE.
17. The apparatus of claim 13 , wherein:
the partial paging information comprises an indication that the unicast paging message is to be transmitted to the UE.
18. The apparatus of claim 13 , wherein:
the random access request message comprises a CET.
19. The apparatus of claim 13 , wherein the instructions executable by the processor to transmit the random access request message comprise instructions executable by the processor to:
perform a listen before talk (LBT) procedure to gain access to the shared radio frequency spectrum band prior to transmitting the random access request message.
20. The apparatus of claim 19 , wherein the instructions executable by the processor to transmit the random access request message further comprises instructions executable by the processor to:
perform the LBT procedure during a contention gap preceding the transmission of the random access request message.
21. The apparatus of claim 13 , wherein the instructions executable by the processor to receive the unicast paging message comprise instructions executable by the processor to:
determine a paging opportunity window (POW) associated with the unicast paging message; and
the instructions are further executable by the processor to power on a receive chain of the UE during the POW.
22. The apparatus of claim 21 , wherein:
the POW comprises multiple transmission time intervals (TTIs).
23. The apparatus of claim 13 , wherein:
the transmission of the unicast paging message is beam-specific.
24. The apparatus of claim 13 , wherein:
the complete paging information comprises an indication of downlink resources associated with a future transmission from a base station to the UE.
25. An apparatus for wireless communication, comprising:
means for receiving a contention exempt broadcast paging message comprising partial paging information for a user equipment (UE) over a shared radio frequency spectrum band during a contention exempt transmission (CET) period and concurrent with a reception of a broadcast discovery reference signal (DRS);
means for transmitting, in response to the received contention exempt broadcast paging message, a random access request message; and
means for receiving, based on the transmitted random access request, a unicast paging message comprising complete paging information for the UE.
26. The apparatus of claim 25 , wherein:
the contention exempt broadcast paging message is staggered for different UEs across different CET periods.
27. The apparatus of claim 25 , wherein:
the contention exempt broadcast paging message is frequency domain multiplexed with the broadcast DRS.
28. The apparatus of claim 25 , wherein:
receiving the contention exempt broadcast paging message further comprises: obtaining from the broadcast DRS an indication of a CET random access channel (RACH) location for the UE.
29. The apparatus of claim 25 , wherein:
the partial paging information comprises an indication that the unicast paging message is to be transmitted to the UE.
30. A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable to:
receive a contention exempt broadcast paging message comprising partial paging information for the UE over a shared radio frequency spectrum band during a contention exempt transmission (CET) period and concurrent with a reception of a broadcast discovery reference signal (DRS);
transmit, in response to the received contention exempt broadcast paging message, a random access request message; and
receive, based on the transmitted random access request, a unicast paging message comprising complete paging information for the UE.