Disclosed are techniques for wireless communication. In an aspect, a user equipment (UE) determines at least one random access channel (RACH) preamble from a first set of RACH preambles, wherein the first set of RACH preambles is for positioning purposes and a second set of RACH preambles is for communication purposes, and wherein the first set of RACH preambles and the second set of RACH preambles are associated with at least one transmission-reception point (TRP), transmits, to the at least one TRP, the at least one RACH preamble to indicate that the UE is involved in a positioning session, receives, from the at least one TRP, in response to transmitting the at least one RACH preamble, an allocation of one or more resources for transmission of uplink positioning signals for the positioning session, and transmits the uplink positioning signals via the one or more resources.