What is L-band in satellite communications?
L-band covers the frequency range of 1–2 GHz. In satellite communications, it is the foundational spectrum for mobile satellite services (MSS) — communications with users who may be moving (ships, aircraft, vehicles) and therefore cannot use large directional antennas. At L-band frequencies, even a small (10–20 cm) omnidirectional antenna can communicate with a satellite, making L-band uniquely suited for handheld satellite phones, low-profile maritime antennas, and emergency beacons.
Key L-band operators and services
Inmarsat: Operates the BGAN (Broadband Global Area Network) service over three L-band GEO satellites (Inmarsat-4 series), providing global coverage for maritime GMDSS safety communications, low-bandwidth data, and voice. BGAN terminals are portable (laptop-sized) and deployable anywhere on Earth. Iridium: Operates 66 LEO satellites in L-band, providing the only truly global MSS coverage including poles — used for satellite phones (Iridium Handsets), Short Burst Data (SBD) IoT, and maritime Iridium Certus broadband. Globalstar: MSS operator using L-band for voice and S-band for return links in a regional GEO/LEO architecture.
Regulatory protection
L-band spectrum is heavily regulated because it hosts safety-of-life services: the 406 MHz band (just below L-band) is the EPIRB/PLB distress frequency; 1,544–1,545 MHz is protected for GMDSS distress traffic. These protections make L-band spectrum politically difficult to reallocate, even as demand from mobile broadband creates pressure on the 1.5/1.6 GHz MSS allocations. 5G expansion has created conflict with L-band MSS allocations in some regions, an active regulatory dispute in the FCC and EU.