Design for system reliability in personal radio signaling

Innovative techniques and attention to frequently-ignored factors have been combined in a new personal radio signaling system. Accessed by means of Touch-Tone^®service, customer dialing errors are effectively controlled through the use of self-checking numbers, eliminating a common cause of missed or false signals. A multiplicity of radio transmitters are arranged to provide adequate building penetration for the entire service area. Simultaneous transmitter operation and low speed, digital receivers work together to make use of multipath radio propagation. Redundancy of equipment and terminal functions assure that electronic failures result in minimal impairment of service. Combining all of the above design features has resulted in a service that is significantly more reliable than that which is provided by systems of earlier design.