Techniques disclosed herein provide for enhanced LTE Positioning Protocol (LPP) Reliable Transport where the receiver of an LPP message sends a non-piggybacked acknowledgement. An example method for executing on a mobile device a protocol session with a location server includes sending a first protocol session message associated with a first protocol session to the location server, entering a wait-for-acknowledgement state in which uplink transmissions from the mobile device to the location server are suspended while waiting for an acknowledgement from the location server in response to the first protocol session message, receiving a second protocol session message associated with a second protocol session which is not an acknowledgement to the first protocol session message but includes information requested in the first protocol session message; exiting the wait-for-acknowledgement state responsive to receiving the second protocol session message; and performing an action using the information received in the second protocol session message.