The generic cellular communication system, shown in , is an integrated network comprising a land base wire line telephone network and a composite wired-wireless network. The land base network is the traditional telephone system in which all telephone subscribers are connected to a central switching network, commonly known as PSTN (Public Switching Telephone Network). It is a digital switching system, providing: i) Switching, ii) Billing, iii) 911 dialing, iv)l-800 and 1-900 calling features, v).
