A Repeater is a network device which is used for Re-transmit the received signal with more power form and also extended geographical topological network boundary for original signal. A Repeater is implemented in computer networks to expand the coverage area of the network and it responsible for power up the weak or broken signal and service remote nodes. Repeater amplify the received/input signal to a higher frequency domain so that it is reusable, scalable and available. Repeater is first used in wired data communication networks due to the limitation of a signal in propagating over a longer distance. After some time it common installation in wireless networks for expanding cell size. Repeater are also known as signal boosters.