A two way dial private mobile system for telephone construction and maintenance

The assignment of frequencies by the Federal Communications Commission in 1958 for use by the Telephone Industry opened the way for obtaining more efficient plant operations through vehicular communications. The mobile communication system described in this paper was designed to serve the needs of the construction and maintenance forces in the Southwest District of the Bell Telephone Company of Pennsylvania. The system employs decentralized dispatching which permits the supervisory personnel to use the service directly from their respective job locations. This is accomplished by incorporating the talking and signaling functions of the radio system into the standard Bell System 500 type telephone set normally used for the wire line service. Since the dispatch points are located in administrative offices where loudspeaker operation must be avoided, mobile to base station dial signaling is employed. Similarly, dial signaling from base to mobile was used to protect the public from indiscriminate loudspeaker operation. Arrangements are also provided for mobile to mobile calls on a dialing basis. This feature is of significant value to the foremen who supervise a number of cable or line crews throughout a relatively large area.