Satellite communication is used to transmit television signals, internet access and telephone calls. (a) Describe how satellite communication works to trans...

(a) How satellite communication transmits a television broadcast:

1. The broadcast signal is transmitted from a ground station (called an uplink station or earth station) up to a communications satellite in geostationary orbit approximately 36,000 km above the Earth. [1]
2. The satellite receives the signal, amplifies it to compensate for signal weakening during transmission, and retransmits (downlinks) it back towards Earth, covering a large geographical area known as the satellite's footprint. [1]
3. A satellite dish at the viewer's home receives the downlinked signal, and a set-top box (decoder/receiver) converts the digital signal into video and audio that the television can display. [1]

(b) Two advantages of satellite communication:

1. Satellites can cover extremely large geographic areas, including remote, rural and oceanic locations where laying cable or fibre-optic connections would be impractical or prohibitively expensive. [1]
2. A single satellite can broadcast to millions of receivers simultaneously, making it highly efficient for distributing television channels, radio stations and emergency alerts. [1]

(c) Two disadvantages:

1. There is a noticeable time delay (latency) because the signal must travel approximately 72,000 km in total (up to the satellite and back), which can affect real-time interactive communication such as video calls. [1]
2. Satellite receiving equipment (dishes, decoders, installation) can be expensive, and the signal can be disrupted by heavy rain, storms or physical obstructions blocking the line of sight to the satellite. [1]