5.5 Wireless Bridging and Internetworking

Wireless Bridging and Internetworking is generally used for connecting buildings and facilities on campuses, within metropolitan areas or between offices in different planetary locations by satellite.

For wireless bridging that does not involve satellites, Frequency Hopping Spread Spectrum (FHSS) radio is generally used. Most land-based wireless bridging and products have a range of 3 miles to 6 miles but some have a 25 mile range. While typically in the 2Mbps range, more recent wireless products can operate in the 10Mbps range.

Microwave Transmission

A common form of wireless media used for bridging and internetworking is the microwave, which was first used for communications after World War II. Essentially, microwaves are a radio frequency technology that use a high frequency electromagnetic wave that vibrates at one GigaHertz and above—at approximately one billion cycles per second. Microwaves use higher frequencies than radio waves and are better able to deliver throughput and communications performance.

There are two basic types of microwave transmission systems.

  1. Terrestrial
  2. Satellite
Terrestrial Microwave Systems
Advantages Disadvantages
Long distance transmission FCC licensing required
Speedy MHz and GHz transmission Performance degraded by weather
Flexible analog or digital transmission Frequency congestion
Transmits voice, video, and data Power lines can interfere
Avoid most right of way problems Flash light pattern transmission