The cellular concept of space-divided networks was first developed in AT&T in the 1940’s and 1950’s. AMPS, an analog frequency division multiplexing network was first implemented in Chicago in 1983, and was completely saturated with users the next year. The FCC, in response to overwhelming user demand, increased the available cellular bandwidth from 40Mhz to 50Mhz.
The second generation (see below) started in the early 1990’s with the advent of the Digital European Cordless Telephone (DECT) system, and the Global System for Mobile Communication (GSM). Data networks were also developed such as HiperLAN and the IEEE 802.11 working group, which produced the 802.11 legacy standard in 1997. The 802.11a and 802.11b revisions were standardized in October 1999.
The third generation started with the CDMA2000 standard in Korea, and UMTS in Europe and FOMA in Japan. The IEEE 802.16 WiMAX specification was approved in December 2001.
Wireless communications networks Lectures