A communication system for integrating a paging system with cellular radio telephones

The present invention relates to a cellular mobile radio telephone system which incorporates an independent paging capability with an existing mobile telephone by taking advantage of call forwarding and redirecting features available on the telephone switching network. When a mobile telephone is set to an active or "on" mode, calls are directed to that mobile telephone using the cellular paging channel and conventional cellular paging procedures. However, when the mobile telephone is set to a sleep mode and the power is switched off, the mobile switching center automatically forwards calls to the mobile to an independent paging system which transmits the call as a paging signal to a small pager associated with the mobile telephone. When the pager receives a page signal as a result of the forwarded call, the pager transmits a low-power signal to the mobile telephone which switches on the power of the mobile telephone. A predetermined time after forwarding the call to the paging system, the mobile switching center redirects the forwarded calls using redirecting procedures to the mobile telephone. By the time the call is redirected, the mobile station has been activated and can now receive the call directly. Because the active pager consumes much less lower than the mobile telephone listening to a paging channel of the cellular system, setting the mobile telephone to the sleep mode results in considerably less battery drain. When the mobile is set to a page mode, the pager functions as a conventional paging device.