Latency and the Coming Internet Reboot

March 09, 2016
By: Doug Mohney

Best effort Internet only goes so far when it comes to real-time applications.  As service providers talk up the magic wonders of software defined networking (SDN) and network function virtualization (NFV), nobody's addressing the elephant in the room -- latency.  Email and web surfing don't need fast response time, but voice, live video, virtual reality, and gaming all need fast and prioritized service.  Listen to the wireless  industry and you can hear the coming wave for an Internet refresh.

Up until recently, the only people who really cared about latency are the high frequency financial traders.  Shaving milliseconds off of transactions means the difference between making millions and losing them.  Getting faster speed for this elite crowd means finding the absolute straightest piece of fiber between point A to point B, because a cable curving through a city along the way means a longer distance for light and packets to travel.  Distance means time and in the world of rapidly buying and selling stocks , time means money.   Microwave towers, once considered obsolete and inferior to fiber,  are even favored in some circles because they literally run in a straight line in transmitting data, unlike fiber's sometimes meandering paths of rights-of-way.

Few today need the purity of a financial trader network connection, but the wireless industry, shadowed by the satellite world, is about to change the rules.  One of the (many, overhyped) promises of 5G networking is low latency.  LTE (News - Alert), depending on the network and who is measuring, adds anywhere from 20 to 40 milliseconds of latency on a one-way trip.  You don't notice it much on a typical voice call, but if you're trying to control a robot in real time or running a bunch of self-driving vehicles at high speed, all the little bits and pieces add up to potential disaster.

The wireless industry is promising sub-millisecond latency for 5G, enabling smooth, seamless real-time control of robotics from a (reasonable)  distance, virtual reality without lag, and ensure gamers can happily kill each other without dying due to waiting for a refresh.

It sounds great, along with 5G's ability to provide gigabit wireless speeds, but just what happens when the next-generation 5G network hits the best-effort, non-optimized for sub-millisecond response Internet?  Real-time applications either need to be "pure" 5G or the existing Internet needs to be supercharged, both in terms of latency (delay) and bandwidth.  Broadband providers -- including (and perhaps especially) the Tier 1 powers that operate cellular carriers -- will have to upgrade their network to reduce existing latencies and work faster with 5G services.

If 5G isn't enough of a push to get broadband providers into cutting latency, a couple low earth orbit (LEO) satellite providers are advocating satellite links as a faster solution to fiber.  It sounds counterintuitive at first, but a larger network of low-orbiting  -- 200 to 300 miles above the earth -- satellites would act as a door-to-door (well, roof-to-roof) relay, bypassing the existing and sometimes confusing multi-hop and delay-adding Internet with all of the routers and best-effort/lowest-cost routing schemes.  In theory, a point-to-point LEO satellite network could substantially cut latency for many types of users, but nobody has put hardware in the sky yet to demonstrate how much speeds can be improved over traditional terrestrial fiber networks.

With the cellular and parts of the satellite industry starting to talk up reducing latency, it is only a matter of time before broadband providers look over their networks for ways to improve speeds and prepare for the sub-millisecond 5G world. Lower latency might be the next "gigabit" in broadband service.




Edited by Stefania Viscusi