Progress through power – removing latency as a satellite broadband concern

01 September 2016 | Tom Eidenschink

Cover

Tom Eidenschink

Blog Author | ViaSat; Corporate Vice President, Strategic Planning


In the satellite communications world, latency is one instance where bigger never means better. Simply put, the less time a data packet takes to travel from the source, to the server, and back again, the happier everyone will be. Latency itself has somewhat been a dirty word – as even on the most technically advanced geostationary (GEO) satellites, the 22,500 mile distance from Earth to the satellite gives latency of around 700 milliseconds (ms). LEO, or low earth orbit, satellites face the same latency issues but, as these satellites are lower to the Earth and have shorter distances to travel, their latency numbers are closer to around 60 - 100ms.

In the satellite communications world, latency is one instance where bigger never means better. Simply put, the less time a data packet takes to travel from the source, to the server, and back again, the happier everyone will be. Latency itself has somewhat been a dirty word – as even on the most technically advanced geostationary (GEO) satellites, the 22,500 mile distance from Earth to the satellite gives latency of around 700 milliseconds (ms). LEO, or low earth orbit, satellites face the same latency issues but, as these satellites are lower to the Earth and have shorter distances to travel, their latency numbers are closer to around 60 - 100ms.

Regardless of the type of satellite, we cannot shy away from the fact that latency is still a problem that exists. However, we must ask ourselves what is most important in a broadband connection? And the answer is speed and bandwidth. To understand how much bandwidth is needed today versus tomorrow, and whether latency will still be an issue, we need to understand how people are using the internet and where growth drivers exist.

What do people do with their broadband connections?

The Cisco Visual Networking Index (VNI) report shows that video is by far the largest share of internet traffic at 65 to 70%. In fact, the 2015 Cisco VNI estimates that video traffic over the internet will grow at a compound annual growth rate of 26% until 2019. In simple terms, that means video volume tripling from 2014 to 2019.

For the developed world it’s easy to see the over-the-top (OTT) story of Netflix, YouTube, Hulu, Amazon and a range of new IPTV streaming devices reflected in those stats. Beyond this, we see new implementations where streaming or interactive video will add to these burgeoning internet numbers.

One case is online learning. Many students living in remote towns typically participate in approximately 7.5 hours of video lessons each week, then spend the rest of the school time in independent home study. Video lessons, similar to a Skype call, enable the interaction between the teacher and the student.

This education application is just one example of an interactive internet video connection that requires massive amounts of bandwidth. As these students live remotely in unconnected, unserved locations how do they meet their need for video streaming and chat services? They can use satellite internet and are virtually unaffected by satellite latency; latency becomes ‘near invisible’ to people using a high-speed satellite internet service. Put simply, the faster you can reach your destination, the less the delay matters.

Give the people what they want

When looking to deal with the latency issue, providers need to ask one simple question: what do their customers want? The examples of video-on-demand providers and initiatives like online learning show that video is a significant growth opportunity: whether users are streaming Mad Max, Mad Men or Mathematics. In this case, many users will prefer networks with more bandwidth and longer latency over systems with less bandwidth and shorter latency. For instance, we’ve seen users in the USswitch from lower-latency terrestrial internet, mainly DSL-based, to higher-capacity satellite services that now have subscriber numbers of 700,000 or more. Trials of service plans that provide more bandwidth without any latency improvement have still shown dramatic increases in subscriber numbers.

The same is proving true outside home internet; for example, with in-flight connectivity. The terrestrial-based Air-to-Ground (ATG) system, the most common form of commercial in-flight connectivity, has almost no latency but is riddled with congestion because ATG has minimal bandwidth. The net result: less bandwidth yields slower overall network speeds as more users log-on and slow down the network. This is one reason why high-capacity satellites are attracting new airlines to switch from ATG to satellite-based in-flight internet services. These are in turn proving more popular with passengers, with some services pulling in take-up rates of nearly 40%. Additionally, airlines that have installed high capacity satellite-based internet service are consistently ranked by passengers and the industry as offering the best in-flight Wi-Fi experience.

These residential and commercial airline experiences show that the stigma of satellite latency is falling away. When you improve bandwidth, even if you keep latency the same, people will perceive a big improvement in the quality of the service. For instance, with video streaming, if you don't have bandwidth and speed, what you get is buffering and a very poor user experience; the video may start faster on a lower-latency service, but it’s anyone’s guess when it will finish. 

The best route to serving customers

Latency is, and will be, part of the satellite system story; however, there is ongoing investment to reduce network delays. There are many techniques to reduce response time other than just reducing latency and many companies are implementing web acceleration, caching, pre-fetching of web pages and other more efficient data processing techniques. A few are even moving beyond that line of thinking, to more innovative, dynamic ways to make content “snap” to the screen.

But rather than being entangled in the latency argument, it is becoming clear that latency is not the core issue providers should address. Satellite services that can deliver more bandwidth, with the ability to focus that bandwidth where it is most needed, are the best investment. Experience with consumers using such services operating today has proven that more bandwidth, not less latency, is what they really want.