Telephony system (MTS) is one of the oldest standards of the mobile phone. It in either direction. means is that, if you from the side lines, fixed the alarm, throw the call to an operator (human) cell phone transmission can be found, and then he call your cell phone, transfer. and your phone is ringing. Like a long distance call, you mobile operators must go, he from you on a mobile phone number that intend to call with it you have asked and a call for you establish.
this system by Bell System was created for the first time on 17 June 1946 was activated. The main equipment of 80 pounds in weight and were in the beginning only 3 channels for all users of the metropolitan area. later permits more was added that the total number of channels to 32 PCs in 3-band).
This service around the year 1980 in large parts of North America were used.
the contract with the IMTS was replaced.