Abstract: A method and apparatus in a communication system operated by a service provider controls utilization of a module (602, 606) added to a portable communication device (122) including a transceiver (302) which communicates with a fixed portion (102) of the communication system. The portable communication device (122) receives (604) a request for utilization of the module. In response, the portable communication device (122) acts (612) to obtain a usage authorization for utilizing the module. The portable communication device (122) disallows (640) the utilization of the module, in response to the usage authorization being unobtainable.

Abstract: A switching system operated from switching areas in a housing of an electronic device includes first and second sets of ambient light sensors and switch sensing means secured in the housing. An ambient sensing circuit and averaging circuit means connects to the first set of light sensors to produce a reference signal representing an average ambient light reaching the first set. A shielding sensing circuit means couples to the second set of light sensors to produce a switch sensing signal in response to an operator shielding ambient light therefrom. A comparison means coupled to the averaging and shielding sensing signal and the reference signal to provide an output after a predetermined delay; and a switch connected to said comparison means performs at least one switching function in response to the output from the comparison means.

Abstract: An interface circuit is coupled between the last stage of an FSK receiver and a limiter to provide a biasing voltage signal to the limiter. The receiver includes a power saver circuit which supplies power on an interrupted basis. The interface circuit contains maximum and minimum detectors which derive and hold voltages corresponding to the maximum and minimum values of the discriminated signal from the receiver. These maximum and minimum corresponding voltages are averaged in a predetermined manner to provide the biasing voltage to the limiter. Thus, a proper bias voltage level can be accurately and quickly determined, and supplied to the limiter when power is supplied.

Abstract: A radio paging device is provided which includes apparatus for preventing turn off of the paging device until all selective calling message signals which are stored in the pagers memory have been displayed. The pager of the present invention further includes apparatus for automatically initiating interrogation of the memory when the user attempts to turn off the paging device.

Abstract: A pager includes means for receiving emergency calls immediately upon reception of the emergency calls and means for receiving non-emergency calls and, storing the non-emergency calls for subsequent readout upon interrogation. The pager is shown implemented in hard-wired logic form and alternatively in a programmable microprocessor form.

Abstract: A current-mode output stage for a digital phase detector has its output current magnitude controllable, with the output polarity determined by the phase detector. Either two or three output states can be provided.