Network repeaters regenerate incoming electrical, wireless or optical signals to preserve signal integrity and extend the distance over which data can travel. With physical media such as Ethernet, data transmissions can travel only a limited distance before signal quality degrades. Consequently, network repeaters are often used to connect cable segments in IEEE 802.3 networks, a standard developed by the Institute of Electrical and Electronic Engineers (IEEE) for Ethernet-based local area networks (LAN). In terms of the Open Systems Interconnection (OSI) model, network repeaters are physical layer devices. Most high-level devices such as switches and routers do not incorporate the functions of network repeaters. In wireless LAN (WLAN) or Wi-Fi networks, access points serve as repeaters only when operating in repeater mode. Some network repeaters are stand-alone and enclosed. Others are integrated circuit (IC) chips or printed circuit boards (PCBs). Stackable, rack-mounted, hardened, full-duplex and wireless devices are also available.

