When an existing system undergoes a unique improvement, it is wise to give that system a new name. This is what happened with the mobile two-way telephone communications system. Under the original plan, a single medium-power transmitter was placed at the centre of population in an urban community having a service area of about 50 miles in diameter. The central transceiver had a capacity of between 100 and 500 channels; however, because mobile telephones are full-duplex, the system was limited to about 250 conversations at a time. Although the costs were high and subscriber lists were small, the system served the community very well. As the community and the subscriber lists grew, users experienced long waiting periods ...

Get Consumer Electronics now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.