You don’t need Comcast’s gigabit broadband. You just need consistent throughput
On February 26, Comcast executive vice president David Cohen said chilling words about the future of his company’s expansion. His remarks came after the FCC issued an order to regulate broadband service under more restrictive rules, and impose principles of network neutrality.
“After seeing the Order, we’ll have to engage in additional internal scrutiny on what our investment plans with respect to broadband will be going forward,” Cohen said to CNN.
I guess they reviewed them quickly. Rather than retreat into a fort made of old pipes held together by coaxial cable, Comcast announced last week that it would be pushing forward with a limited, national roll-out of 2 gigabit per second (Gbps) broadband followed by a nearly complete upgrade of its footprint to 1Gbps.
By the end of 2015, the company said, about 18 million households could select 2Gbps service, starting with Atlanta in just a few weeks. By the end of 2016, almost every house it serves could pay for 1Gbps access. The 2Gbps service relies on fiber, while the 1Gbps service uses an advanced version of cable-modem technology.
But does gigabit to the home even matter? For most people, not really. It’s theconsistency of throughput that matters more than quantity.
Turn on the tap
A variety of broadband problems can spell trouble for streaming video. First there’s poor latency—the round-trip time it takes for a video server to respond to a data request. Then there’s the possibility of high jitter, which you experience when data arrives in spurts. Finally, a high error rate can cause video artifacts and pauses. Put all of these together, and you’ll get a streaming experience that’s worse than no video at all.
Broadband networks typically cite just their bandwidth, which is the peak raw data rate of a network pipe. Bandwidth doesn’t speak to the actual data rate of the content that’s delivered. For this, throughput is the true measure—it’s the amount of data per second that you actually get. And problems with latency, jitter, and error correction can impact even a high-throughput connection.
Local gigabit Ethernet networks score well in all five properties—from bandwidth to error correction—when you use good cabling. So, with 1Gbps of bandwidth, close to 99 percent is often available as throughput with very low latency, jitter, and error rate issues. Ethernet switches allow that level of quality across every connection, too.
The very first Wi-Fi standards started with low bandwidth, high latency, and very low throughput relative to bandwidth. They also had problems with consistent, error-free delivery. The 802.11g standard introduced in 2003, for example, promised “54 Mbps,” which was only its raw bandwidth rate. In practice, speeds of 15- to 20Mbps were more likely, and then only in areas with few other networks. But now, after 16 years of development, the 802.11ac standard has started to approach gigabit Ethernet in the right conditions using a high-frequency band.
Quite a bit of broadband acts like 2003-era Wi-Fi. You’re promised “up to 25Mbps,” but measurements typically show 10- to 15Mbps, if that. During periods of high use, such as during prime time or new episodes of Game of Thrones, your video streaming goes wacky, and stalls, dies, stutters, or pixelates.
What most of us are looking for in “gigabit” broadband is freedom from those problems, and not raw bandwidth.
Video killed the telecom star
When broadband speeds are discussed, companies promoting high rates typically talk about “downloading the Library of Congress in five minutes!” or “getting an entire Blu-Ray movie in two seconds!”
That kind of talk distracts and distorts the utility. Unless you’re running a server operation, you rarely (if ever) need an actual throughput above 50Mbps (which is far below the newly advertised gigabit speeds). What you really want, even in a crowded household, are low-latency, low-jitter, low error-rate connections. In other words: consistent throughput without any footnotes.
The Comcasts of the world focus on bandwidth because it’s fundamentally easier to deliver “up to X Mbps!” than it is to provide seamless, consistent data. During our normal, everyday use of email, web browsing, and file syncing, we notice when we have to wait. The progress bar, the spinning hands. Pre-Dropbox, it was common to mount remote storage like a local drive and deal with the pain of Internet slowness. Cloud-based folder sync adds a different kind of latency—you have to wait for files to show up—but feels immediate.
When you get a chance to work on an unbounded network, like dropping in at a fiber-backed business or university, you can still find yourself waiting on many of those things, because the connection between you and a remote server can be congested, or the remote system can be overloaded.
So, for the most part, the difference between a high-quality 50Mbps broadband connection and a newfangled gigabit connection relates to video downloads and streaming. Because of scarce bandwidth, all the services—iTunes and otherwise—have built clever coping tactics that only work better when you have more throughput or better consistency.
For instance, the last Harry Potter movie is a 5GB download as 720p from the iTunes Store. That’s eight minutes at 50Mbps and 24 seconds at 1Gbps—but, either way, you can start watching in seconds with just a few Mbps. Streaming high-quality compressed video using H.264 can run from a few Mbps for 720p at 30 frames per second (fps) up to tens of Mbps for 1080p at 60 fps. Dynamically adjusting streaming services take care of adjusting upward or downward.
In a household with multiple people watching distinct programs at once, you can wind up limited by throughput, and then you start to need more overhead. That’s where gigabit service comes in.
On the road to a gigabit highway
American’s average broadband bandwidth and throughput has been slowly but inexorably moving upwards, even as ISPs have engaged in a variety of behaviors that throttle some video services in their connections with other networks. Gigabit broadband would be lovely, if priced reasonably, unless the ISPs only have straws, not pipes, connecting to Netflix, iTunes, Amazon Prime, and others.
And 4K video could change things again. 4K legitimately requires substantially more throughput—hundreds of Mbps for a good compressed stream. So that may shift the broadband game once again if 4K becomes popular in the next few years. Rather than stream 4K, customers might choose a much higher throughput method: express shipping. A FedEx plane full of 4K compatible Ultra HD discs (up to 100 GB each) could easily top exabits per second without straining any broadband plumbing at al