On-demand user equipment positioning

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

receiving a synchronization signal using a physical broadcast channel (SS/PBCH) from a base station;

receiving a minimum system information block (MSIB) or a master information block (MIB) indicating support for uplink UE positioning, the MIB or MSIB received using a Physical Downlink Control Channel (PDCCH) or a Physical Downlink Shared Channel (PDSCH);

transmitting a request to participate in at least an uplink UE positioning procedure using a UE positioning request channel; and

receiving a configuration for the uplink UE positioning procedure using the PDCCH or the PDSCH, wherein the configuration is included in a system information block (SIB), wherein the configuration comprises positioning reference signal configuration; and

transmitting an uplink positioning reference signal according to the configuration.

2. The method of claim 1 , wherein the positioning reference signal has:

a first format if the UE is in a first radio resource control (RRC) state; or

a second format if the UE is in a second radio RRC state.

3. The method of claim 2 , further comprising:

determining the first format or the second format of the positioning reference signal based on at least one of:

a service requirement of communications performed by the UE; or

operating bandwidth of the communications.

4. A method for wireless communication by a base station (BS) comprising:

transmitting a synchronization signal using a physical broadcast channel (SS/PBCH) to a user equipment (UE);

transmitting a minimum system information block (MSIB) or a master information block (MIB) indicating support for uplink and/or downlink UE positioning, the MIB or MSIB transmitted using a Physical Downlink Control Channel (PDCCH) or a Physical Downlink Shared Channel (PDSCH);

receiving a request from the UE to participate in at least one of an uplink or a downlink UE positioning procedure;

in response to the request, transmitting a configuration for the at least one of the uplink or downlink UE positioning procedure using the PDCCH or the PDSCH, wherein the configuration is included in a system information block (SIB), wherein the configuration comprises positioning reference signal configuration; and

receiving an uplink positioning reference signal at the base station, in accordance with the configuration, and wherein:

the request is to participate in the uplink UE positioning procedure;

the configuration is for the uplink UE positioning procedure;

a first format if the UE is in a first radio resource control (RRC) state; or

a second format if the UE is in a second radio RRC state.

5. The method of claim 4 , further comprising determining the first format or second format based on at least one of:

a service requirement of communications performed by the UE; or

operating bandwidth of the communications.

6. The method of claim 4 , wherein the configuration indicates at least one of a numerology, periodicity, or reference signal (RS) pattern for the positioning reference signal.

7. An apparatus for wireless communication by a user equipment (UE) comprising:

at least one processor coupled to a memory, the processor configured to generate a request to participate in at least one of an uplink UE positioning procedure or a downlink UE positioning procedure; and

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

receive a synchronization signal using a physical broadcast channel (SS/PBCH);

receive a minimum system information block (MSIB) or a master information block (MIB) indicating support for the uplink and/or downlink UE positioning, the MIB or MSIB transmitted using a Physical Downlink Control Channel (PDCCH) or a Physical Downlink Shared Channel (PDSCH);

transmit the request to participate in the at least one of an uplink UE positioning procedure or downlink UE positioning procedure;

receive a configuration for the at least one of the uplink UE positioning procedure or the downlink UE positioning procedure in response to the request, the configuration received using the PDCCH or the PDSCH, wherein the configuration is included in a system information block (SIB), wherein the configuration comprises positioning reference signal configuration; and

receive a downlink positioning reference signal or transmit an uplink positioning reference signal according to the configuration, wherein:

the request is to participate in the uplink UE positioning procedure and the received configuration is for the uplink UE positioning procedure, and

the at least one processor and the transmitter further configured to:

transmit an uplink positioning reference signal in accordance with the configuration.