The US Cellular Telecommunications Industry Association, meeting in San Antonio, Texas, has taken the first step in deciding a digital cellular standard for the US, and the system chosen means that the US system could end up fully compatible with the Groupe Speciale Mobile standard established for the pan-European system. The US industry group has chosen the Time Division Multiple Access system proposed by L M Ericsson Telefon AB in preference to a Frequency Division Multiple Access system proposed by Motorola Inc and AT&T Co. To create multiple channels on a single radio transmission, time division multiplexing chops each signal – phone conversation – into bursts, each allotted its time slots alongside bursts from many other concurrent conversations; and frequency division multiplexing splits the carrier wave into multiple sub-carriers of carefully-spaced frequencies. The equipment for the US system is not expected to be ready before 1991.
US CELLULAR BODY TAKES STEP TOWARDS GSM EURO-STANDARD
