A method for execution by a mobile station (MS) in a mobile communications network, the method comprising: receiving a first MS identifier from the network during a ranging operation involving the MS; using the first MS identifier to extract the contents of at least one message received from the network during said ranging operation; using a second MS identifier, different from the first MS identifier, to extract the contents of at least one message received from the network after said ranging operation is complete. Also, a method for execution by the base station, comprising: outputting a first message destined for the MS, the first message including a first identifier for use by the MS during a ranging operation; determining that said ranging operation is complete; outputting a second message destined for the MS, the second message including a second identifier for use by the MS in subsequent communication with the network.