Motorola Corporation

Kwok K Choi

Tri Thien Dang

Thomas Casey Hill

Morris A Moore

Douglas I Ayerst

Leonard E Nelson

Malik J Khan

Lowell C Hufferd, Iii

Lowell C Hufferd Iii

A selective call receiver (106) has a frequency synthesizer (708) for scanning a plurality of frequencies to determine a control channel to receive a signal and a receiver (704) for receiving the signal representative of an available frequency associated with a geographic region. The signal includes a channel identifier (404), a frequency assignment (406) and an active channel indicator (408). A processor (712) associates the channel identifier (404) with the frequency assignment (406) in response to the active channel indicator (408) indicating an available frequency of the geographic region and a memory (720) stores channel identifiers (404) associated with frequency assignments (406) designating available frequencies (408). The receiver (704) receives an address (333) and the channel identifier (404) on the control channel, a decoder (714) decodes the channel identifier (404) associated with the frequency assignment (406) to determine the available frequency where a message will be transmitted and the frequency synthesizer (708) switches to the available frequency indicated by the channel identifier (404) for receiving the message.

Method for determining available frequencies in selective call receivers

A communication system (100) providing analog message re-transmission on demand comprises a base station (114) and at least one portable communication transceiver (118). The base station (114) transmits an address (414) identifying the portable communication transceiver (118) to which a voice message is directed, and a session number (415) modulated in a first modulation format and a compressed analog message (418) representing the voice message modulated in a second modulation format. When the signal quality of the voice message played back in the portable communication transceiver (118) is perceived by the user to be unintelligible, the user can receive from the base station (114) a re-transmission of the compressed analog message (418) by generating a request for re-transmission of the compressed analog message (418).

Apparatus for message re-transmission on demand

A method and apparatus remotely retrieves messages intended for an acknowledge-back pager (400, 700) in a communication system including a fixed portion (100) and the pager (400, 700). The communication system has provisions for interconnection with a user by telephone. The fixed portion (100) accepts (502) a selective call origination from a caller, including a message intended for the pager (400, 700) and sends (504) the message to the pager (400, 700) in response. The pager (400, 700) stores (506) the message within a pager memory (418). Thereafter the fixed portion (100) accepts (508) a selective call origination from the user, including a predetermined retrieval code associated with the pager (400, 700). The fixed portion (100) sends (510) a predetermined retrieval command to the pager (400, 700) in response, and the pager (400, 700) retrieves the message from the pager memory (418) in response. The pager (400, 700) transmits (512) the message retrieved to the fixed portion (100), which then stores (514) the message within a controller memory (232, 602) and sends (514) the message by telephone to the user.

Method and apparatus for remotely retrieving messages intended for an

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Coral Springs, FL, United States of America

Kwok K Choi