Abstract: A portable paging system communicates a paging message including a first portion having at least a selective call address (406) and a first activation code (407), and a second portion having a first segment (409) of an audio portion, to a selective call receiver (300). In the portable paging system, an input device (104) prompts an originator to request an extension of the second portion of the paging message, the extension including at least a second segment (410) of the audio portion. Upon receiving an affirmative talk time extension request from the originator, and if extending the second portion of the paging message does not exceed a predetermined number of extension requests or a predetermined total broadcast time allocated for the second portion of the paging message, a paging terminal controller (210) extends the second portion of the paging message.

Abstract: An on-site selective call receiver interacts with a wide area selective call system to increase the probability of timely message reception by a selective call receiver capable of operating in either the wide area or the on-site selective call system. A frequency shifting signal is transmitted from the wide area system in response to addition of the selective call receiver to the on-site registry or automatic detection of entry of the selective call receiver into the on-site selective call system coverage area. The selective call receiver shifts to the wide area frequency in response to detecting that the receiver is out of range of the on-site system signal or in response to a signal transmitted by the on-site system in response to deletion of the receiver from the on-site registry or detection of the exit of the receiver from the on-site coverage area. The on-site system increases message throughput by interleaving data messages with voice messages.

Abstract: A battery charging device wherein the charging current level is controllable by a thermal circuit responsive to battery temperature also includes a circuit responsive to battery voltage and a timing circuit. The timing circuit is activated when a battery is inserted into the device for charging and immediately times a very brief interval. If the battery voltage exceeds a predetermined level during the timed interval, the charging current level is reduced as by the thermal circuit. The circuit protects both cold and charged batteries from damage due to overcharging.