InnovOil visited the Thales Alenia Space centre in Rome to preview SES' last batch of four O3b medium Earth orbit (MEO) satellites before their launch in the first half of the year.
O3b stands for “Other 3 billion,” the number of people without broadband access.
MEO satellites orbit 8,000 km above Earth – geostationary satellites orbit 35,750 km from Earth. The lower orbit means the MEO satellites provide latencies of 75 milliseconds for a one way data transfer. Geostationary satellites have a latency of 270 milliseconds between Earth and satellite.
The four satellites will join SES' 16 current satellites to increase their coverage. They orbit around the equator at a speed of 18,918 km per hour, orbiting the Earth five times per day.
Each satellite carries 12 antennae, each of which emits a beam with a 700-km diameter footprint. This means that each antenna covers 384,845 sq km.
The satellites send and receive data to and from a pair of 2.4 metre ground dishes. The antenna on one dish will track the satellite currently being used, while the second tracks another. As the first satellite goes under the horizon, the second terminal links up with the next satellites to ensure there is no gap in transmission.
However, this means that there are two points of failure in the uplink system. If one link goes down, it can create a gap as the other terminal has to compensate and locate the new satellite.
Morten Hansen, vice president Segment Market Management Energy at SES Networks told InnovOil: “What’s new with O3b MEO is the reduced latency and the high throughput available on our solution. That’s something that oil and gas companies are starting to utilise. We have deployments in several parts of the world, from Brazil, West Africa, Angola, Equatorial Guinea to the Gulf of Mexico.”
These developing markets lack the telecommunications infrastructure of areas like the North Sea. MEO satellites look like they can make certain tasks practical.
Hansen noted that the International Telecommunication Union’s end-user multimedia QoS categories standard specifies at least a 100 millisecond single trip latency as key for command/control and voice/video applications.
While ROV inspections do not need latencies of 100 milliseconds or more to be viable, operating a work class ROV will be more difficult if there is a noticeable lag between the operator’s actions and the ROV’s actions.
Working in the cloud can be unpleasant. People using cloud apps perceive latencies of up to 100 milliseconds as instantaneous. With an average typing speed of around 40 words per minute, it takes about 250 milliseconds to type a single character. Geostationary satellites produce a noticeable lag with 270 millisecond latencies.
While SES' MEO satellites are an improvement over geostationary satellites, the benefits they provide are incremental.