Satellite communications connect units that cannot reach each other directly: ships at sea, aircraft over enemy territory, units behind mountains, and drones flying far away. The frequency band used determines the character of the link.
| Band | Characteristic | Military use |
|---|---|---|
| UHF | Narrowband, small antennas, works under foliage | Handheld and vehicle radios (e.g. the American MUOS) |
| X band (SHF) | Medium bandwidth, little affected by rain | Classic military broadband (e.g. WGS, Skynet, Syracuse) |
| Ka band | Lots of bandwidth, more sensitive to rain | Broadband for drones and headquarters |
| Ku band | Commercial, high capacity | Commercial networks such as Starlink |
| EHF | Very resistant to jamming and interception, lower data rate | "Protected" links for nuclear and strategic command and control (e.g. AEHF) |
Military networks are expensive and limited in capacity; armed forces therefore rely more and more on commercial SATCOM. That provides a lot of capacity, but makes them dependent on a company — as Starlink in Ukraine showed (see 9.2).