Satellite internet and Starlink

In short: Satellite internet serves places without cable. Classic satellites at 36,000 km altitude have high delay, low-flying constellations such as Starlink only about 25 to 60 ms.

In more detail: Distance is decisive: radio signals need time for the path Earth–satellite–Earth, which you feel as latency.

In Depth

• GEO (geostationary): 35,786 km altitude, appears to stand still over one spot. Round trip about 500 to 700 ms latency. Good for television and simple data access, bad for games, telephony and remote access.
• LEO (low orbit): About 550 km. Thousands of satellites sweep quickly across the sky, the antenna switches continuously. Latency usually 25 to 60 ms, data rates often above 100 Mbit/s.
• Technology: A flat phased-array antenna steers the beam electronically. Links run to ground stations, partly also via lasers between satellites.
• Limits: Capacity per cell is shared, heavy rain and a clear view of the sky (trees, buildings) affect quality.
• Use: Rural areas, ships, aircraft, emergency communication.
• Comparison: A good complement where DSL or fibre is missing.

See also: GPS and satellite navigation