Last-mile access
Wireless backhaul, can be very cost effective and resilient. Base stations can have multiple antennas which can be directed in any direction to connect to any other peer base station, providing many point-to-multipoint (PtMP) connections from one location. These wireless links can share (re-use) a common spectrum because they are spatially separated by the directional antennas. In addition, with cognitive radio technology, the base stations can dynamically select a different spectrum range when needed to achieve spectral or physical separation to avoid signal interference. A group of base stations linked together can form a mesh network which can reroute traffi c should one or more base stations fail.
Mesh network topology for backhaul
The last consideration for truly redundant backhaul networks is electrical power. Base stations need power, of course. If power lines are disrupted, all of the base stations on these lines are taken down, too. When this happens, there is little value in all of the other redundancies built into the base stations. Practical considerations for power redundancy very much depend on how much power is needed to operate the base station. Generally, installing gas generators for backup power at each base station is not practical! However, if a base station’s power requirement is low, cost-effective alternatives are available. For example, if the base station’s power budget is less than 25 Watts, redundant power can be provided over the base station’s core network connection via Power-over-Ethernet (PoE) technology. Solar panels can be an option for systems requiring up to approximately 100 Watts. Of course, the key determining factor for power redundancy is the overall power consumption of the wireless equipment in the base station.
