Definition Edit

Satellite communications is

[a] telecommunications service provided via one or more satellite relays and their associated uplinks and downlinks.[1]

Overview Edit

"Satellite communications are limited in terms of the environment in which they can be deployed. First, a ground terminal that connects on-site devices to the satellite(s) in orbit requires an unobstructed view of the sky. Satellite links, much like GPS, will not function indoors and can experience poor performance in areas with physical objects in the way, such as near tall buildings or in forested areas. This is further complicated when the satellite network being used has few physical satel­lites in orbit, since the ground terminal will have fewer options and thus an increased chance of obstruction. Additionally, weather and particulate matter can affect satellite communications, potentially limiting usefulness during severe storms or in thick smoke. This is an active area of research and development, both industrial and academic, because it directly affects commercial viability of satellite networks for phone, television, and Internet access.

"Second, due to the fact that wireless signals must travel to the satellite (which often orbits at a high altitude to maintain geosynchronous orbit) and back down to the ground to connect two end points, satellite communications incur significant latency on the order of hundreds of milliseconds. Therefore, satellite links are more suitable to call-and-response-style voice and video communications, sharing and accessing information, and data telemetry. As space rover operators can attest, real-time remote control of robotics is less advisable over such links. The issue can potentially be addressed using high-altitude solar-powered drones to fill the same role of satellites. . . .

"Third, ground terminals require careful setup by trained technicians before they can establish a link with a satellite. This is because they must be carefully pointed as close to the satellite as possible for the best signal. This issue can be addressed with self-aligning ground terminal dishes that use their location (gleaned via GPS) and the known celestial coordinates of the available satellite(s) to coarsely aim in the right direction and then fine-tune based on signal strength from the ]satellite. Rapid movement makes this impossible for a human technician to address, so mobility requirements should also be carefully considered before satellite links are deployed."[2]

References Edit

  1. ATIS Telecom Glossary 2011.
  2. Research Roadmap for Smart Fire Fighting, at 31.

See also Edit