Sumarry
BASIC OF
WIRELESS NETWORKS
The first comercially available
radio and telephone system, known as the improved Mobile Telephone Service
(IMTS), was put into service in 1946. In order to us IMTS, a tall transmitter
tower was erected near the center of a
metropolitan area. Several assigent channels were then transmitted and received
from the antenna atop this tower and any vechile within range could attempt to
seize one of those channels and complete a call. Given this constructions, the
number of channels available did not come close to satisfying the demand.
Two important characteristics of
cellular systems contribute to their usefulness. The first is their controlled
handoff. As subscribers are diving out of one cell and into another, their
mobile ( subscribers) units, in conjuction with sophisticated electronic equipment
at the cells sites [also known as base stations (BS)] and the telephone
switching offices [ also known as mobileswitching centers, (MSCS)], are
transferred from one frequency set to another with no audible pause. Second,
system were designed to locate particular subsrcibers by paging them in each of
the cells. After locating the vechile in which the United States, called Group
Speciale Mobile (GSM), now known as Global system for Mobile Communications.
