Abstract: The procedure for Programmable System Determination (PSD) utilizes the over-the-air programming protocol and procedures which support the Over-The-Air Service Provisioning (OTASP) feature in accordance with established industry standards (TIA/EIA/IS-683). Using the OTASP procedure, the re-scan timer and digital acquisition timer of a mobile station are programmable by the network carrier as Number Assignment Modules (NAMs) within the mobile station. OTASP Data Messages permit the NAM values to be programmed without requiring intervention by a third party. In the OTASP procedure, programming occurs while the mobile station and base station are in the Conversation Substate using designated OTASP Data Messages. Certain OTASP Data Messages are specified according to the standard as providing a pre-determined procedure, while others are set aside for manufacturer-specific information.