On demand positioning reference signals and per band deployment aspects

1. A method of wireless communication performed by a user equipment (UE), comprising:

transmitting, during a positioning session, a first request for transmission of first on demand positioning reference signals (PRS);

measuring, during the positioning session, the first on demand PRS in a first band;

measuring, during the positioning session, periodic PRS transmitted in a second band different from the first band, wherein transmitting the first request for the transmission of the first on demand PRS and measuring the periodic PRS transmitted in the second band are based on positioning requirements of the positioning session; and

sending, to a positioning entity, positioning measurements of at least the first on demand PRS and the periodic PRS.

2. The method of claim 1 , further comprising:

transmitting, to a location server, a capability message indicating that the UE can support operation on at least the first band and the second band.

3. The method of claim 1 , wherein:

the first on demand PRS are transmitted by a first set of base stations, and

the periodic PRS are transmitted by a second set of base stations.

4. The method of claim 3 , wherein:

the first set of base stations is the same as the second set of base stations, or

the first set of base stations is different from the second set of base stations.

5. The method of claim 3 , further comprising:

receiving, from the location server, assistance information for at least the first set of base stations and the second set of base stations.

6. The method of claim 5 , wherein the assistance information includes locations of at least the first set of base stations and the second set of base stations.

7. The method of claim 5 , wherein the assistance information indicates at least a number of the first set of base stations operating in the first band and a number of the second set of base stations operating in the second band.

8. The method of claim 3 , further comprising:

determining at least a number of the first set of base stations operating in the first band and a number of the second set of base stations operating in the second band based on detecting at least the first on demand PRS and the periodic PRS.

9. The method of claim 1 , further comprising:

receiving an indication that only the first band supports on demand PRS.

10. The method of claim 1 , wherein:

the first request is transmitted on the first band, and

the first request being transmitted on the first band indicates that the first request is for the first on demand PRS to be transmitted in the first band.

11. The method of claim 1 , wherein the first request is transmitted on the second band.

12. The method of claim 1 , wherein the first request includes an identifier of the first band.

13. The method of claim 1 , wherein transmitting the first request for the transmission of the first on demand PRS and measuring the periodic PRS transmitted in the second band being based on the positioning requirements of the positioning session comprises transmitting the first request for the transmission of the first on demand PRS and measuring the periodic PRS transmitted in the second band based on a positioning need not satisfied by the periodic PRS transmitted in the second band.

14. The method of claim 13 , wherein the positioning need is based on a geometric dilution of precision (GDOP) threshold.

15. The method of claim 1 , further comprising:

transmitting a second request for transmission of second on demand PRS in a third band;

measuring the second on demand PRS in the third band; and

sending, to the positioning entity, positioning measurements of the second on demand PRS.

16. The method of claim 1 , wherein:

the UE transmits the first request to each of a first set of base stations, and

the first on demand PRS are transmitted by the first set of base stations.

17. The method of claim 1 , wherein:

the UE transmits the first request to a location server or a serving base station,

the first request is sent by the location server or the serving base station to each of a first set of base stations, and

the first on demand PRS are transmitted by the first set of base stations.

18. The method of claim 1 , wherein:

the first band comprises a first frequency range, a first frequency band, a first component carrier, or a first positioning frequency layer, and

the second band comprises a second frequency range, a second frequency band, a second component carrier, or a second positioning frequency layer.

19. The method of claim 1 , wherein:

the positioning entity comprises a positioning engine at the UE, and

the method further comprises calculating a location of the UE based on the positioning measurements of at least the first on demand PRS and the periodic PRS.

20. The method of claim 1 , wherein

the positioning entity comprises a location server or a serving base station.

21. The UE of claim 20 , wherein:

the first on demand PRS are transmitted by a first set of base stations, and

the periodic PRS are transmitted by a second set of base stations.

22. The UE of claim 21 , wherein:

the first set of base stations is the same as the second set of base stations, or

the first set of base stations is different from the second set of base stations.

23. The UE of claim 21 , wherein the at least one processor is further configured to:

receive, from the location server via the at least one transceiver, assistance information for at least the first set of base stations and the second set of base stations.

24. The UE of claim 23 , wherein the assistance information includes locations of at least the first set of base stations and the second set of base stations.

25. The UE of claim 23 , wherein the assistance information indicates at least a number of the first set of base stations operating in the first band and a number of the second set of base stations operating in the second band.

26. The UE of claim 21 , wherein the at least one processor is further configured to:

determine at least a number of the first set of base stations operating in the first band and a number of the second set of base stations operating in the second band based on detecting at least the first on demand PRS and the periodic PRS.

27. A user equipment (UE), comprising:

a memory;

at least one transceiver; and

at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to:

cause the at least one transceiver to transmit, during a positioning session, a first request for transmission of first on demand positioning reference signals (PRS);

measure, during the positioning session, the first on demand PRS in a first band;

measure, during the positioning session, periodic PRS transmitted in a second band different from the first band, wherein the at least one processor is configured to transmit the first request for the transmission of the first on demand PRS and to measure the periodic PRS transmitted in the second band based on positioning requirements of the positioning session; and

send, to a positioning entity, positioning measurements of at least the first on demand PRS and the periodic PRS.

28. The UE of claim 27 , wherein the at least one processor is further configured to:

cause the at least one transceiver to transmit, to a location server, a capability message indicating that the UE can support operation on at least the first band and the second band.

29. A user equipment (UE), comprising:

means for transmitting, during a positioning session, a first request for a first set of base stations to transmit first on demand positioning reference signals (PRS);

means for measuring, during the positioning session, the first on demand PRS from the first set of base stations in a first band;

means for measuring, during the positioning session, periodic PRS from a second set of base stations operating in a second band different from the first band, wherein transmission of the first request for the transmission of the first on demand PRS and measurement of the periodic PRS transmitted in the second band are based on positioning requirements of the positioning session; and

means for sending, to a positioning entity, positioning measurements of at least the first on demand PRS and the periodic PRS.

30. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a user equipment (UE), cause the UE to:

transmit, during a positioning session, a first request for a first set of base stations to transmit first on demand positioning reference signals (PRS);

measure, during the positioning session, the first on demand PRS from the first set of base stations in a first band;

measure, during the positioning session, periodic PRS from a second set of base stations operating in a second band different from the first band, wherein transmission of the first request for the transmission of the first on demand PRS and measurement of the periodic PRS transmitted in the second band are based on positioning requirements of the positioning session; and

send, to a positioning entity, positioning measurements of at least the first on demand PRS and the periodic PRS.