Skip Links

Q&A: What the FCC's Wi-Fi expansion means for you

And why Aerohive's Matthew Gast has an engineer's crush on the FCC chairman

By , Network World
January 23, 2013 10:04 AM ET

Page 3 of 4

But the radio that can use the new channels will have a better signal-to-noise ratio. It can pick a different data rate, and make use of 256 QAM. It will be 25% faster. In a hospital with big medical images or a classroom with streaming video, these will all load faster.

Actually, the new channels will also help other Wi-Fi clients even if they can't use them.

How so?

All kinds of networks just trundle along, with their load increasing, and they work until they collapse. You can see this in highway commuting at rush hour: if I leave home too late, the traffic load gets too much and I spend way too much time in second gear.

The new channels remove some of that load. If just you and I are sharing a Wi-Fi network and you run on 11ac and I'm not, I get faster data rates. You take less time to do what you do. And it reduces traffic congestion. It's like carpooling: even though I don't carpool, those who do carpool mean there are fewer cars on the highway when I'm driving. So the new spectrum improves the Wi-Fi experiences even for those with older devices.

So what happens next?

A press release is not an official commission action. Those FCC actions are based on rules, under what's called Part 15. There are rules you need to operate in this spectrum: you can use this much power, use a modulation like this; you can't interfere with weather radar, and so on.

What matters is the precise technical rules that will be put in place. The FCC issues a "notice of proposed rulemaking" or NPR, with a public comment period. This formal rule-making process by the FCC starts Feb. 20.

What will Wi-Fi vendors do? Can they modify existing products to use the new channels, or do they have to build new ones?

That depends on the nature of the rules. What Wi-Fi chip vendors realized years ago was they could build very flexible radio chips, in effect software-defined radios, and reprogram them to do different things. For a 5 GHz radio, I might [be able to] load software to support new 20MHz channels or other features.

If the new rules are simple enough, it's possible to just update the software on the chip and an access point radio, for example, can access the new channels. This depends on a whole bunch of things. For example there will be some kind of testing procedures for the chips, which in effect will be asking something like "can I use channel 72?" Now we already do this with DFS channels. So in the best case, there will be a very small change or even none at all. Worst case: completely new software to implement and pass these new tests.

Then systems vendors like Aerohive will have to take our products to an FCC-authorized testing lab, pass the prescribed tests and get an FCC number that indicates we passed.

What kind of time frame are we talking about?

I have no idea. The FCC is very, very careful. They're aware that a lot of their work has safety implications. The hard part is figuring out, in their engineering division, the tests that will have to be run. Unfortunately that is not an overnight process.

Our Commenting Policies
Latest News
rssRss Feed
View more Latest News