Inmarsat

Inmarsat, headquartered in London and founded in 1979 as an intergovernmental organization before privatization in 1999, was one of the world's pioneering and most significant mobile satellite communications companies — operating the world's most extensive L-band GEO satellite network for maritime, aviation, government, and enterprise mobile connectivity — acquired by Viasat in 2023 in a $7.3 billion transaction that created one of the world's largest integrated satellite communications companies.

Inmarsat pioneered mobile satellite communications for maritime vessels, establishing the global maritime distress and safety system (GMDSS) standard that requires all vessels over 300 gross tons in international waters to carry Inmarsat-compatible emergency communications equipment — a mandate embedded in the International Maritime Organization's (IMO) SOLAS (Safety of Life at Sea) convention. Inmarsat's L-band constellation (currently I-4 and I-6 series GEO satellites) provides omnidirectional, highly reliable connectivity even in adverse weather through the 1.5-1.6 GHz L-band, which penetrates rain, atmospheric absorption, and moderate cloud cover better than higher frequency bands.

Inmarsat's product portfolio spans: BGAN (Broadband Global Area Network) for portable satellite terminals used by journalists, humanitarian organizations, and military forces in remote areas; FleetBroadband and Fleet One for maritime ship broadband and IoT; SwiftBroadband for aviation passenger connectivity and cockpit communications; and Global Xpress (GX) — Inmarsat's Ka-band high-throughput satellite service providing 50-100+ Mbps for maritime and aviation broadband that competes with Viasat's ViaSat-3 and SES's O3b mPOWER.

Viasat's acquisition of Inmarsat combined Viasat's U.S. government satellite communications, consumer broadband, and ViaSat-3 Ka-band constellation with Inmarsat's L-band global GMDSS franchise, aviation IFC market leadership, and GX Ka-band network, creating a full-spectrum competitor to SES, Intelsat, and SpaceX Starlink for maritime and aviation connectivity.