Abstract: The process of the present invention first synchronizes to incoming messages from the base station. The first data word is received and stored in the radiotelephone. The error code in the data word is next checked to determine if errors exist in the word. If there are errors, the word is corrected. This process is repeated on another data word and the second received word is compared with the first. If the words are not equal, the receiver remains on until at least two words are equal or the entire length of the message is received. If the words are equal, the word is processed by the radiotelephone and the receiver is turned off for the remaining portion of the message until the next synchronization word is to be received.

Abstract: A process for use in a radiotelephone that has multiple telephone numbers for use in different cellular radiotelephone systems. The numbers are stored in number assignment modules (NAM's) with its corresponding system identification code. The process compares a received system identification code with the ones in memory (103). If a match is found, the radiotelephone user is prompted to select the new telephone number (104). If the new number is not selected or the identification code is not found in memory, the radiotelephone becomes a roaming unit and enters an idle state (107) waiting for an incoming call.

Abstract: A radiotelephone subscriber unit which overcomes the problem of attempting to access an undesired radiotelephone system is disclosed. A comparison between the system identification transmitted on a control channel of a desired radiotelephone system and the system identification transmitted on an access channel is made during the access process of the subscriber unit. Access is permitted if the control channel system identification and the access channel system identification match.

Abstract: The apparatus and method for transferring radio specific data from the memory of an integral logic unit of a radiotelephone to a second, replacement, memory is disclosed. Security of the data is realized by encoding the radio specific data with an operative number generated from a seed number. If the radio specific data is properly transferred to the second memory, the radio specific data is deleted from the memory of the integral logic unit.