Diagram:

Explanation:

 Paging systems are communication systems that send brief messgaes to subsciber. Message may be either a numeric, alpha numeric or voice message.

 A message is sent to a paging subscriber via the paging system access number with a telephone keypad or modem. The issued message is called a page.

 The paging system then transmits the page throughout the service area using base stations which broadcast the page on a radio carrier.

 Paging system vary widely in their complexity and coverage area while simple paging systems may cover a limited range of 2 to 5 km or may even be confined to with in individual buildings, wide area paging systems can provide world wide coverage.

 Though paging receivers are simple and inexpensive, the transmission system required is quite sophisticated.

 Wide area paging systems consists of a network of telephone lines, many base station trasnmitters and large radio towers that simultaneously broadcast a page from each base station.(this is called simulcasting)

 Large trasnmitter power and low data rate are necessary for maximum coverage from each base station