Latency Really Matters, O3b Argues

For any number of new networks, latency is as important as bandwidth. That is true for satellite constellation O3b, the coming fifth generation mobile network standard, and likely for cloud computing networks generally.

In the satellite trunking business (long haul or wide area network transport), which at present is the biggest single revenue driver for O3b, it arguably is latency, not bandwidth, which is the primary user experience advantage for a medium earth orbit (MEO) constellation, compared to the more-traditional geostationary approach, argues David Burr, O3b VP.

And a surprisingly large number of application types provide better user experience when delivered over a MEO constellation, rather than a geostationary constellation.

Basic web site downloads, Internet video streaming, video conferencing and regular voice calls, video conferencing and Interactive gaming are consumer and business applications that work better over a MEO link, because of the much-lower latency.

Also, many business applications such as remote database access and interactive transaction processing contain software timers that do not adjust for long delays over geosynchronous satellites.

Banking applications and airline reservation and scheduling applications are examples.

So the point is that bandwidth, while important, might not be as important as latency reduction, for satellite trunking operations, especially those related to applications and services running Internet Protocol.

“Latency does matter,” said Burr. On an 8,000-kilometer route between London and Lagos, Nigeria, an undersea cable might have latency of about 80 milliseconds.

A geostationary satellite link might have latency of 496 milliseconds. The same path, using the O3b constellation, might have latency of about 133 milliseconds, O3b said.

As a practical matter, geosynchronous satellite users must wait almost 750 msec. before they start getting data, whereas the lower latency O3b satellite link will receive it nearly four times sooner, O3b argues.