Satellite Communications Characteristics – GateHouse

Satellite Communications Characteristics

Spotlight

Satellite connections behave very differently to fixed line and cellular networks. In the following you will find listed the basic characteristics of a satellite link, which makes the satellite link different from other communications links.

  • High latency
  • Significant jitter
  • Limited & shared bandwidth
  • Variable service level
  • Non-trivial setup
  • Many different failure modes

 

These are the basic characteristics that makes satellite IP communications different from your typical modern fiber, cable or ADSL internet connection. Satellite links provided with geostationary satellites have significant latencies of 480 milliseconds and up. The variation in how long it takes data to get through is typically high (jitter) and the throughput is depending on effective buffering mechanisms and buffer size in order to be able to obtain the expected bandwidth. The bandwidth itself is limited (hundred-of-kilobit to megabit-range) and is typically shared with other users. The service level can vary widely; You may be lucky and have a channel all to yourself, or unlucky and be in a spot where the network is congested, and if so, you only get a fraction of the bandwidth, or possibly no service at all.

In situations where you need to demo or test terminals or applications, the uncontrollable and sometimes unpredictable parameters can be quite problematic. To obtain full control of the test or demo conditions you can emulate the data link instead. This means that your terminal or application works as under real-life scenarios, but defined by the conditions you set up. This eliminates the need to use expensive air-time, but more importantly it provides you with complete control of the conditions for a test or demo. An example of use could be a situation where you want to demo your application to a potential customer. To prove functionality and stability, you can stress test your solution or application, proving that your product can handle errors or challenges such as latency, jitters etc.

Test or demo on-air furthermore entails a great deal of preparation. Setting up and connecting a satellite terminal is fairly easy, but not trivial. Users have to be aware of satellite pointing, service costs, and external factors that may affect them, such as weather fade or network congestion. Finally, satellite communications require a number of systems and technologies to work together in concert, and if just one of these fails, the operation of the others is impacted. The result is that there are many different ways you can experience impact of the signal when using satellite communications as a data link.

Comprehensive testing of a terminal or application in a lab is essential to obtain more robust, and better performing products. A controlled and reproducible test environment makes it easier to identify the source of a problem and avoid the problems caused by the large number of uncontrolled parameters when doing a test or demo on air.

Satellite Communications Test Capabilities

Decrease costs and time-to-market by employing one or more of our satellite communications test and demo tools.

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