Broadband Wireless Internet Access (BWIA) News

Television Broadcasters Need To Embrace Whitespace Usage... Or Else

In his post White spaces could be the broadcaster's best hope, Brough Turner says, in part:

But fighting the White Space Coalition is short sighted. The NAB faces a much bigger and more powerful enemy — mobile operators.

The White Spaces Coalition merely seeks permission to use spectrum where NAB members are not using it, i.e. on a non-interference basis as "secondary users" with purely secondary rights.  

The mobile industry wants it all.  They'd prefer that broadcast spectrum be taken back and auctioned off for mobile use.

I saw the same thing Brough sees, back in March 2008 in a post called The White Space Sucker Punch in which I said, in part:

What the CTIA knows in its filing is that television broadcast white spaces is merely a brief stopgap on the way to severely consolidating the television broadcast spectrum(s) considerably more. Remember that there were originally 83 television broadcast channels. 70-83 became the original (analog) cellular telephone band and the 800 MHz public safety and commercial two-way radio bands. Now we've given over channels 52-69 to more commercial and public safety communications use. It's just a matter of time ... and demand... before there's yet another round, or two, of further consolidation of television broadcasting and "freeing up" of, say, channels 31-50 - a further 120 MHz.

But license-exempt communications use of television broadcast white space would make another reallocation of television broadcast spectrum totally impossible! Once there are millions of license-exempt devices (and networks of devices) out there "in the wild", they couldn't be recalled. The television white spaces would be "forever polluted" for the kind of "stupid wireless" command-and-control communications systems that wireless telephony technology uses. WiMAX is no different than wireless telephony systems in this regard - there are no "cognitive" capabilities in "licensed" communications systems because the license is "the intelligence" in the system that insures that systems function well and don't cause interference. Cognitive techniques, on the other hand, assume that there will be interference, and accommodate interference when it does occur... and keep working.

The wireless carriers are thinking strategically... that's why they're positing the current problems in delivering reliable service as a "lack of spectrum" issue. They have allies within the FCC that are sympathetic to that position. (That the FCC is sympathetic is a byproduct of most FCC personnel being lawyers and thus seeing "spectrum as property", and the wireless carriers [arguably] need more spectrum/property, but that's a discussion for another time.)

In comparison, the television broadcasters are thinking tactically, that they don't want to share their spectrum with white spaces usage. They think they're winning the fight by requiring Whitespace devices to use a central database and a "Mother, May I ?" "permission-to-transmit" paradigm, but that paradigm will just make it very easy to "clear out" those devices when television broadcast spectrum is reassigned yet again to wireless communications use. What the television broadcasters need to do is to acquiesce to uncoordinated (but non-interfering) usage from not only Whitespace devices, but also things like neighborhood television transmitters (even lower power than low power TV, and usage by Amateur Radio operators.

That's... if they want to stay in the "spray modulated RF energy across a wide area" business. Eventually, they won't be. The question they have to ask is if now is the time they want to be forced into consolidating their operations into an even smaller chunk of spectrum from the onslaught of the wireless carriers. If yes, then they'll keep fighting Whitespace operations and won't invite Amateur Radio operators to use their spectrum on a non-interference basis.

Steve Stroh

If I Was In College, And Interested In BWIA...

I recently had an undergrad student in India contact me to critique his application letter for US Grad Schools. While he knew some of the buzzwords, he didn't seem to know much about what was really going on in BWIA. Here's some advice for students in a similar position.

1. Get an Amateur Radio license and get on the air in some capacity, even if it's a 2 meter portable working through repeaters (but you'll have more fun experimenting with things you didn't imagine possible, like SoftRock. This isn't just advice for US students - Amateur Radio exists in almost all countries. You'll learn more about the real world of wireless communications actually getting some hands-on experience than anything you'll learn in a class. The physics of wireless are universal, like the relationship of frequency vs wavelenth vs antenna length. You'll learn simple, but profound things like that when you try to build an antenna that actually works the way the Matlab model says it should.

Some words of warning that shouldn't be required, but unfortunately... are. Amateur Radio is infested with way too many crusty old farts who just seem to hate the idea of someone under the age of sixty getting an Amateur Radio license to use "their" frequencies for something other than Morse Code (CW). Just get your license and proceed to ignore them and use Amateur Radio to learn and experiment. You have as much right to be using Amateur Radio spectrum as the old farts. More right, in my opinion, in fact, because students are the future of Amateur Radio, if it's to have one, and they're the past.

A good start / challenge is to get Amateur Radio digital gear up and running using Linux, and then proceed to write some "good stuff" for Amateur Radio with open source / Linux code. Two great pieces of software I recommend highly are D-RATS and Xastir.

2. Become familiar with all of the work that you can possibly find about the use of open source software and hardware as it applies to wireless communications. Gnu Radio is a great place to start.

3. Off the top of my head, some promising areas of research related to BWIA that a grad student could dive into, in my opinion, are:

• Self organizing wireless mesh networks and peer-to-peer wireless networks
• Use of IPv6 in wireless networks
• The license-exempt spectrum allocation model, and why it works. Bonus points and personal attention from me if you can ferret out an explanation of my Darwinian Effect of License-exempt Wireless and give me a cogent synopsis. (And for those of you really paying attention... GREAT topic for a thesis.)
• Software Defined Radio
• "Smart" (adaptive) antenna systems / Phased Array Antenna systems
• Use of 60 GHz band for both LAN and point-to-point metro use
• New generations of satellite technology (we're never going to fiber the entire world)
• Coexistence of 802.15 wireless technologies with 802.16 wireless technologies
• Adaptive use of bands occupied by licensed systems, like television broadcast whitespace
• Use of license-exempt systems in a coordinated way (using cheap GPS receiver chips as a highly accurate timebase) to create wide-area coverage similar to cellular
• User-scale wireless mapping systems that can plot coverage of wireless systems (which could then feed in to adaptive antenna and dynamic power control to help fill in the gaps)
• Wireless "maker" devices that can combine license-exempt services in new and innovative ways like citizens band radio, Family Radio Service, MURS, pico-power FM broadcast transmitters, Zigbee, wireless USB, etc. (look it all up - you're supposed to be good at research)
• What went wrong... and what went right with Metricom Ricochet (bonus points, and again, personal attention from me if you can ferret out the original inspiration of Metricom Ricochet)
• Another great topic for a thesis is why the US Military RADARs are vulnerable to interference from simple, cheap 5 GHz Wireless LAN devices.
• "Stealth" wireless communications techniques - if you can't be "heard", likely you're not causing interference.

4. Dive deep into the capabilities of some of the more advanced wireless chipsets, like Atheros. I've been told that talented engineers have made the Atheros chipsets do things that even Atheros didn't know was possible. It also helps to learn what's possible by picking just a few good companies and learning the capabilities of their various product lines as representative of what's possible in BWIA. Two such companies that I recommend highly are Redline Communications and Dragonwave. You'll quickly realize why I recommend studying those two companies in particular. One last company to study... that's incredibly innovative in its own niche is MikroTik.

5. Do whatever it takes to utterly divest yourself of the notion, beloved in the legal industry, that spectrum is a finite resource or "property". Read all you can about what David Reed has to say about the subject.

6. Find the nearest Wireless Internet Service Provider (WISP) and intern with them for a summer, or a quarter. Like Amateur Radio, it will be some of the best fundamental knowledge you could ever hope for. Consult WISPA to find one nearby.

7. When you think you have enough perspective about something related to BWIA, write a book(let). Yes, really. Numerous services make it incredibly easy - Lulu, Booksense, Cafe Press, etc. Do not pay a company to "help" you - just get it out there using one of these services. If may never sell more than a handful of copies, but you'll be out there with some perspective, and you may be surprised at the results. Hint... books on demand never need become obsolete. When you've learned that some of the things you originally wrote were wrong or incomplete, revise it into the 2nd edition... then the 3rd, etc. You can do such things with a print on demand model. Hint - price the first few editions low - you're not trying to make (lots of) money - you're just trying to establish credibility. Once people have bought your book(let), you're an actual published author.

8. Form a wireless Special Interest Group at your school to meet face to face once a month or so to talk about wireless-related tech. This kind of personal interaction pays incredible dividends. Find some interesting people - cellular reps, wireless equipment vendor reps, all are delighted to come to talk to groups.

9. Try to attend a big wireless conference like CTIA Wireless or even IWCE. Believe me, I know that they don't make it easy for students or anyone but deep-pocketed corporate types, but it's really worth attending if you can find a way to get in free. Bonus points if you're hands-on enough to be able to figure out why anyone with any interest in wireless communications would want to spend an often-rainy three-day weekend in Dayton, Ohio every Spring.

10. Join IEEE as a student and soak up as much knowledge from IEEE and its member organizations as you possibly can. The IEEE has a lot of different groups (societies) related to wireless, and the IEEE standards organizations such as IEEE 802.11, 802.15, and 802.16 have, essentially, created much of the wealth of wireless technology we now enjoy.

If you use any of the advice to further your academic career and/or find it useful, I'd enjoy hearing about it, either in the comments or via email.

Steve Stroh