Radio-Based Wireless Point-to-Point Network

Radio-Based Wireless Point-to-Point Network
Wireless point-to-point networks (often called wireless metropolitan area networks) use technologies
very similar to wireless LANs. Therefore, this section concentrates on technological
aspects differing from wireless LANs.
A radio-based wireless point-to-point network (see Figure 2.15) is currently the most common
method for providing connectivity within a metropolitan area. These products have highly
directional antennas to focus the signal power in a narrow beam, maximizing the transmission
distance. As a result, spread spectrum products operating under one watt of power can reach
single-hop transmission distances of 30 miles. The actual transmission distance of a particular
product, though, depends on environmental conditions and terrain. Rain, for example, causes
resistance to the propagation of radio signals, decreasing the effective range. A mountainous
area will also hamper the transmission range of the signals. Radio-based wireless point-to-point network data rates are 11Mbps for the shorter-range products
operating over two- to three-mile links. Applicable products operate over a 30-mile link,
but they will transmit at much lower data rates to obtain the longer range. In addition, these
products use either spread spectrum or narrowband modulation.