Satellite signal problems

Updated February 21, 2017

Satellite TV and Internet equipment use radio wave technology to send transmissions to and from communications equipment placed into a low, stationary orbit around the Earth. This technology, almost 50 years old, has a number of drawbacks; a weak signal, blocked signal, misaligned dish or lack of authorised reception hardware could prevent communication.

Line of sight

Radio waves used to propagate data, through either an analogue or digital signal, require a line-of-sight, or unobstructed view from the transmitter to the receiver. This is the reason that terrestrial radio stations place the transmitter antenna on the top of large towers or buildings, to expand the effective horizon of the signal. When using a satellite the signal must not be blocked by precipitation, trees, buildings or mountains. Satellite television normally travels one-way from the satellite to the TV equipment, using a phone line for account authentication. Some newer systems will employ two-way communication, much like satellite Internet service, which can be identified by the dish's extra transmitter node. The two-way dishes are more prone to problems caused by blockage of the signal, as they have relatively weak transmitters. Rain, clouds, snow or even low-flying aircraft can prevent the radio wave from reaching either location.

Misaligned dish

A common problem with satellite communications is a misaligned dish. When the dish was installed by the provider, a technician used sophisticated instruments to point the dish at the satellite in the sky and measure signal strength. In Earth's northern hemisphere most communications satellites are in the southern sky, as they orbit closer to the equator to give maximum coverage. The sky is sectioned off into degrees and an object in orbit can be located by a set of coordinates, much like how latitude and longitude work on the ground. On most satellite dishes, there are adjustable mount plates that are marked with a range of settings for the azimuth and zenith. They can be locked in, to point the dish at the satellite and keep it there. Falling objects, birds or rodents can disturb the calibration of these mounts. It may take a signal strength meter to reacquire the lost satellite.

Authentication issues

Since the 1980s, satellite transmissions have evolved, and the ability to track users for any number of reasons has become a complicated issue. Tracking and monitoring usage is not just to charge a user for service, the satellite has a finite capacity of users that it can accommodate at one time. To prevent the equipment from becoming overwhelmed, and to limit malicious intent, the satellite works very much like a large computer server in space. Any deviation in login credentials or change in the equipment could cause the satellite to not "recognise" a valid user.

Rare instances

In some extremely rare cases, the satellite could just be "jammed" by a closer signal on the same frequency. This has been known to occur with 2.4 Ghz cordless phones and wireless network routers, and it can occur with any radio transmission. A signal on the same frequency, but closer than the desired signal, will cause reception problems. Satellite equipment placed too close to large microwave towers or near high-powered ham radio antennas will experience a disrupted or nonexistent signal.

Satellite has been lost

Satellites, as man-made technological instruments, can break down and stop working in any location. Unfortunately, sending a technician to repair the broken equipment may not be feasible, and the companies usually take the opportunity to send up a new satellite instead. This may cause a "backup" satellite to attempt to take over the functions of the old one, but a backup is not always available.

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About the Author

Eli Laurens is a ninth-grade physics teacher as well as a computer programmer and writer. He studied electrical engineering and architecture at Southern Polytechnic University in Marietta, Ga., and now lives in Colorado.