O3b Networks Ltd. is a network communications service provider building and operating a medium Earth orbit (MEO) satellite constellation primarily intended to provide voice and data communications to mobile operators and Internet service providers.

O3b is the satellite constellation designed for telecommunicationsand data backhaul from remote locations.The constellation is owned and operated by O3b Networks, which is a wholly owned subsidiary of SES S.A. The O3b constellation began offering service in March 2014.

The network combines the relatively large reach of satellite with high speed and medium latency to deliver satellite Internet services and mobile backhaul services to emerging markets. The name “O3b” stands for “[The] Other 3 Billion”, referring to the population of the world where broadband Internet is not available without help.
Since early 2018, the network has consisted of 16 Ka-based satellites in the O3b satellite constellation orbiting at an altitude of 8,062 kilometres (5,009 mi), which is less than one quarter of the altitude of geostationary satellites, significantly reducing satellite latency.

Each satellite is equipped with twelve fully steerable Ka band antennas (two beams for gateways, ten beams for remotes) that use 4.3 GHz of spectrum (2×216 MHz per beam) with a proposed throughput of 1.6 Gbit/s per beam (800 MBit/s per direction), resulting in a total capacity of 16 GBit/s per satellite. Each beam’s footprint measures 700 km in diameter.O3b claims a mouth-to-ear one-way latency of 179 milliseconds for voice communication, and an end-to-end round-trip latency of 140 ms for data services. The maximum throughput per TCP connection is 2.1 Mbit/s. For maritime applications, O3b claims a round-trip latency of 140 ms, and connectivity speeds of over 500 Mbit/s.[
The satellites are powered by gallium arsenide solar arrays and lithium ion batteries and weigh approximately 700 kilograms (1,500 lb) each.

In September 2017, SES announced the next generation of O3b satellites and placed an order for an initial seven from Boeing Satellite Systems using a new satellite platform based on Boeing’s 702 line of scalable buses. Expected to launch in 2021, the O3b mPower constellation of MEO satellites for broadband internet services will “be able to deliver anywhere from hundreds of megabits to 10 gigabits to any ship at sea” through 30,000 spot beams. Software-defined routing will direct traffic between the mPower MEO satellites and SES’ geostationary fleet.

O3b will transform communications by deploying an innovative Medium Earth Orbit satellite constellation, capable of offering customers connectivity which is better, faster and more affordable. O3b has the flexibility to meet the capacity and network demands of Resellers, Telcos, Mobile/Wireless Operators, ISPs and Government Entities in 177 countries across Asia, Africa, Latin America and the Middle East.