Repeaters are network devices operating at physical layer of the OSI model that amplify or regenerate an incoming signal before retransmitting it. They are incorporated in networks to expand its coverage area. They are also known as signal boosters.
When an electrical signal is transmitted via a channel, it gets attenuated depending upon the nature of the channel or the technology. This poses a limitation upon the length of the LAN or coverage area of cellular networks. This problem is alleviated by installing repeaters at certain intervals. Repeaters amplifies the attenuated signal and then retransmits it. Digital repeaters can even reconstruct signals distorted by transmission loss.
So, repeaters are popularly incorporated to connect between two LANs thus forming a large single LAN. This is shown in the following diagram −
According to the types of signals that they regenerate, repeaters can be classified into two categories −
According to the types of networks that they connect, repeaters can be categorized into two types −
According to the domain of LANs they connect, repeaters can be divided into two categories −