BellSouth Corp has enlisted radio technology to provide its rural customers with digital telephony services, a move which has landed International Mobile Machines Corp a $27m contract: its Ultraphone Wireless Digital Loop Carrier system is to be installed at 35 sites within four of the states within BellSouth’s fiefdom by 1990, the idea of the system being that providing radio capacity in the local loop allows geographically inaccessible customers to be connected to the telephone network where the high cost of cable and wiring would otherwise isolate customers; four simultaneous conversations can be transmitted over one radio channel and International Mobile hopes to sell the system to other Bells and is currently talking to a number of other telephone companies and is developing a digital cellular telephone application that can be integrated onto the cellular system.