Fixed radio links are frequently used for various purposes within telecommunications and broadcast networks, on either a permanent or temporary basis. Usually the justification for using a radio link instead of a wired or optical fibre link relates to geography or economics. They can often be used to provide fixed communication links between stations in a network supporting a different service (such as mobile telephony): an application known as 'infrastructure' or 'backhaul'.
Types of fixed radio links
Point-to-point (PP) links are typically used within telecommunications core networks. They may also be used within local access networks (connecting users to the core network) and as broadcast contribution and distribution links.
Point-to-multipoint (PMP) links are normally used within access networks, enabling network operators to provide services without the need to install conventional cables. A point to multipoint network topology provides a communication route (on a single radio channel for each sector) from one central point to a number of terminals where users are located. Each user location may be served directly from the central location or via one or more radio repeaters.
Multipoint to multipoint (MPMP) links, sometimes called mesh networks, provide communication pathways between various system nodes where each node has a communication pathway with a few of its near neighbours. These pathways share a limited number of radio channels. Most of the nodes will be at user terminal locations, whilst one or several of the nodes might be associated with a core network interface.
The above fixed radio links applications are also frequently referred to as Fixed Wireless Access (FWA) or as Fixed Wireless Systems (FWS), a term recently adopted by ITU-R SG 9.