Courtesy of James Duncan Davidson, here’s a snap from the Spectrum 2.0 panel at eComm09.
The general discussion was about the lessons learned from light licensing of wireless spectrum in the US, on the success of Wi-Fi and the failure of UWB, and what we can realistically hope to gain from the White Spaces licensing regime. As a person with a foot in both camps – technical and regulatory – it was an interesting exercise in the contrast in the ways that engineers and policy people deal with these issues. In general, hard-core RF engineer Peter Ecclesine and I were the most pessimistic about White Space futures, while the policy folks still see the FCC’s Report and Order as a victory.
In lobbying, you frequently run into circumstances where the bill you’re trying to pass becomes so heavily encumbered with amendments that it’s not worth passing. Rather than get your policy vehicle adopted in a crippled form, it’s better in such circumstances to take it off the table and work with the decision-makers to revive it in a future session without the shackles. While this is a judgment call – sometimes you go ahead and take the victory hoping to fix it later – it’s dangerous to pass crippled bills in a tit-for-tat system because you’re conceding a win in the next round to the other side.
I suggested that the FCC’s order was so badly flawed that the best thing for White Space Liberation would be to have the court void the order and the FCC to start over. This message wasn’t well-received by Rick Whitt, but I had the feeling Peter is on board with it.
The problem with the White Spaces is that the FCC couldn’t make up its mind whether these bands are best used for home networking or for a Third (or is it fourth or fifth?) pipe. The power limits (40 milliwatts to 1 watt) doom it to home networking use only, which simply leads to more fragmentation in the home net market and no additional WAN pipes. That’s not the outcome the champions of open networks wanted, but it’s what they got.
eComm, incidentally, is a terrific conference. The focus is very much on the applications people are developing for mobile phones, and it’s essential for people like me who build networks to see what people want to do with them, especially the things they can’t do very well today. Lee Dryburgh did a fantastic job of organization and selecting speakers, and is to be congratulated for putting on such a stellar meeting of the minds.
“The power limits (40 milliwatts to 1 watt) doom it to home networking use only, which simply leads to more fragmentation in the home net market and no additional WAN pipes. That’s not the outcome the champions of open networks wanted, but it’s what they got”
Gigi Sohn made the same argument in her debate with Thomas Hazlett last week at Catholic University: that the permitted power levels for the white spaces were too low like Wi-Fi. The problem with this argument, as you rightfully noted in a previous blog here, is that range is not an “unmitigated good”. What is signal to you is interference to someone else.
When I used to design and build Wi-Fi networks, I often only used 1/10th of the permissible power level because using smaller cell sizes permitted maximum spectrum reuse. 10 mW radios and small built-in antennas is more than sufficient for most enterprise applications if you had a dense deployment of access points. Wi-Fi is already too powerful in many cases, and I can get too many of my neighbor’s access points coming in to my home with strong signal levels. Bumping up the power level for Wi-Fi would be a really bad idea and even Brett Glass in rural Wyoming will tell you he often doesn’t use his peak budget.
I can’t see how any unlicensed spectrum can be useful as a WAN solution unless there was strict guidelines on spectrum etiquette and ad hoc schedulers that worked across multiple providers. But that would require quite a bit of engineering and there’s no guarantee that this could work well if there are too many ISPs trying to use the same spectrum.
While your details are correct, you’re missing the larger point. If we want to use the White Spaces for home (and enterprise) networking, the existing power limits are fine and we’re good to go with existing medium access protocols such as Wi-Fi and the Wi-Media MAC. However, we already have a lot of channels for Wi-Fi, especially in the 5.8 GHz band where new H-band channels 100-140 were recently added to shipping products, so this order doesn’t address an unmet need.
But the problem is that the White Space advocates were actually looking for a 3rd Pipe solution, which involves higher power limits as well as spectrum etiquette. The spectrum etiquette problem (how competing systems mediate access to the air) is a digital communications problem, and the FCC is an analog regulator. The FCC literally doesn’t know how to begin drawing up rules for digital systems that share spectrum. But they have taken a few steps down that road, as you’ll see when the video of this panel goes live. There’s actually a fair bit of standards work that’s been done already on the coordination of schedulers on wireless systems, and it’s a topic I’ve covered on this blog since 2002.
There is no need, and in fact no good reason, to use the “white space” frequencies for home netowrking. There is already more spectrum allocated for that purpose than for any other! They already get 20 MHz in the 900 MHz band, plus 60 in the 2.4 GHz band, plus several HUNDRED in the 5 GHz band. To allocate more for this purpose, when there is ZERO space allocated for outdoor wireless broadband, is not just silly but dangerously unwise. The FCC should void its earlier ruling and devote the band to creating third, fourth, fifth, and Nth pipes — enabling broadband competition.
I didn’t mention the points you made Richard, but I saw your point and I agreed with it. Since you’ve already stated it better than I can, there was no point in me being redundant.
Fair enough.
Brett, you’re absolutely right.
There’s 80 MHz of spectrum in the 2.4 GHz range (20 MHz of optional guard band since you can do 4 channels with intelligent placement of adjacent channels). Some people will call this spectrum worthless, but it’s worth $6 billion if we project the value from the 2.5 GHz auction.
There’s another 10 MHz in the 1.9 GHz spectrum with DECT, which is a much more spectrally efficient way to use the spectrum for voice applications.
There’s the 20 MHz of 900 MHz spectrum which is darn close to 700 MHz.
There’s 3.65 to 3.7 GHz range for 802.11y.
There’s 480 MHz in the 5.3 to 5.9 GHz range.
So yes, there’s really no need for another piece of spectrum for home networking.