Abstract: A method and apparatus for notifying of changes made to contact information (700, 800) in an electronic contact list includes updating a first electronic contact list with updated information (710) and electronically sending the updated information (720) to at least one second contact list (820) in an electronic format based upon changes made to the first contract list. Optionally, an acknowledgment (850) may be sent by the recipient of the contact information in order to delete the recipient from the sender's contact list.

Abstract: A radio frequency (RF) communication system transmits information including multiple data formats. The RF communication system receives the information (102) and parses the information into a plurality of nibbles (126), each of the nibbles comprising a predetermined number of bits. The plurality of nibbles are then provided to a terminal (10) as a message (154), the message is encoded by the terminal (10), and the encoded message is transmitted to a transmitter (15) for transmission therefrom.

Abstract: A paging receiver (15) for receiving secure radio frequency (RF) communications comprises a receiver circuit (102) for receiving and demodulating a signal to obtain information. A memory device (108) is coupled to the receiver circuit (102) for storing the information. A de-encrypter (110) is coupled to the memory device (108) for de-encrypting the information and a decoder (112) is coupled to the de-encrypter (110) for decoding the de-encrypted information to derive a message. User input controls (120) selectably generate a user input signal. A controller (114) is coupled to the memory device (108) and the user input controls (120) for causing the memory device (108) to provide the information stored therein to the de-encrypter (110) in response to the user input signal being equivalent to a predetermined de-encryption signal.

Abstract: Increased efficiency in the use of a communications channel between a Control Unit and a multiplicity of terminal or satellite units by utilizing the combinations of the unit address code words and their complements as coded commands and automatically returned responses. At least one combination of the Control Unit address code words and word complements can be manually entered at any one of the satellite units to serve as a special response to one combination of the respective satellite address code words and word complements, to cause a change of function or operation at the Control Unit. The system may be coupled to a Host Computer and normally the information received by the Control Unit would be encoded for transmission to the computer, in which case the change of function could be the disenabling of transmission to the Host Computer.

Abstract: A two-way communications system for use with a host computer includes a control unit, a base station and multiple radio/data terminal units. The control unit interfaces directly with the computer but uses a radio link to the portable units. Voice and data signals can be transmitted and data between units is decoded, sorted, stored, encoded, and sent to its destination in accordance with predetermined protocol in queue discipline. An extensive self-diagnostic system is included. An active redundancy arrangement switches between two control units/base stations on a regular schedule if both units are up, and instantaneously if the "on" unit goes down.