Repeater is the equipment used in telecommunication networks to regenerate the signal. Transmission range of signals is limited by distortion, interference and absorption of the transmission media. Regeneration of the transmitted signals allows us to incrase the transmission range. Repeaters operate at the physical layer signals (the first layer of the OSI model) and do not try to interpret the data transmitted by it under the terms of their correctness (consistency). Information sent via the cable is distorted in proportion to its length. One of the devices that amplifies and regenerates signals from cable is the repeater. Therefore, repeater increases size of the physical network. They usually comprise is the use of several repeaters. In telecommunications, the term repeater can mean:
Repeater repeats (copies) the received signals and amplifies it. This is done by increasing the level of the received waveform without changing the frequency. This device type is simple. It can be applied in the network with equal architecture and use the equal protocols and transmission techniques. However, repeater can be connected to network segments with different transmission media. Installation of a repeater is very simple, it does not require any configuration and is transparent for other network devices. It is treated as a node in each of the segments connected to it. Repeater adapted to the transmission speed of the network transmits packets at the same rate, with results that it is slower solution than a bridge. It is less intelligent device than router. It does not provide isolation between segments, it also does not isolate defects and does not provide packet filters. Therefore, information, often local, penetrates into other segments by loading them unnecessarily. Therefore, its price is relatively mild. Repeaters are now being used in small LANs.