ABSTRACT
The ordinary telephone system is an example of wire telephony, whereas a pager, mobile, etc. are the examples of wireless or radio telephony, in which signal does not flow through wires but flows through space in the form of radiowaves. A cordless telephone basically is a wireless telephone. The receiving antenna of his base receives the same, demodules and sends to the telephone exchange of the area. The paging transmitter sends out a coded radio signal which is received and decoded by the paging receiver. The moving person then contacts a prearranged telephone number and gets the detailed message. The pager receiver is always to be worn on the body. It has a marked effect on its antenna performance. The mobile phone has replaced cordless telephone, pager etc. Cellular mobile services offer telephone and data communication services even when the calling party or the called party or both are mobile.
