Abstract: Failures in a message exchange, during a procedure for determining the location of a mobile station, are alleviated by providing a retry mechanism. Upon receipt of a particular failure message, such as the SMS Cause Code 33, rather than abort the location operation, the node receiving the failure message retransmits its last previous message. In an Assisted GPS (AGPS) example, essentially, whenever the Position Determining Entity (PDE) 25 receives an SMS Cause Code 33 from the mobile switching center (MSC) 15, it will resend the last previous Invoke message, without delay or alteration. This will give MSC 15 another chance to deliver the message to the mobile station 5 and ideally continue the message flow until the mobile station has been successfully located. The PDE 25 may retry a particular Invoke message one or multiple times. The receipt of other SMSCauseCode values may still cause the message exchange to abort.