Saturday, August 27, 2005

I Could Do Better

Business Week Online has an article from a Standard & Poor analyst which does a good job of perpetuating several popular WiMAX myths, confusing various technologies, and generally confusing the hell out of anyone who's trying to understand broadband wireless access.

Let's start with the simple fact-checking that you would think a professional analyst writing in a respected publication would have been able to get right: WiMAX compatibility testing is being performed by CETECOM, el Centro de Technologia de las Comunicaciones, S.A., not "Cenecom, the WiMax Forum Certification Laboratory, which opened in early August". CETECOM has been around since 1991; it's the WiMAX testing that started in August.

Then there's the ever-popular, "has a service range of up to 50 kilometers and provides data rates of up to 280 megabits per second per base station." This is even more outlandish than the usual hype, which limits its irrational exuberance to 70 Mb/s and 50 kilometers.

That "up to" is a great two words. My car can go up to 200 miles per hour and get up to 100 MPG. If I pushed it off a high enough cliff; otherwise, its performance is somewhat less.

I suppose with 80 MHz of spectrum and subscribers within half a mile of the base station (with line of sight to the base station antenna) that would enable the base station to run all the subscribers on 64QAM you could get 280 Mb/s out of a single base station. And I suppose with a really tall tower, really flat terrain, and remote units with their antennas sitting in a window facing the base station antenna, you could push a signal 50 km. But in anything approaching the real world, you're not going to get either 280 Mb/s or 50 km.

Realistically, with a 5/5.5 MHz channel (US WCS or BRS spectrum), you'll get around 13 Mb/s user payload, and in something approaching normal suburban/rural terrain, you'll be able to push a reasonable signal out 3 to 5 miles. Useful? Sure, especially for DSL-equivalent services where you can run oversubscription of 25:1 or higher. But let's not get carried away.

And by the way, that WCS or BRS spectrum is licensed and usable for WiMAX (though the WiMAX Forum profiles for 2.3/2.5 GHz haven't been completed yet). So saying that "there's no authorized radio frequency spectrum from the Federal Communications Commission for the issuance of WiMax licenses" is, well, wrong.

The article also says, "AirBand, Clearwire, and TowerStream... believe bandwidth is adequate within 50 megahertz to 500 megahertz bands for Wi-Fi and WiMax without seeking radio frequency licenses from the FCC." Actually, AirBand and Towerstream use frequencies in the 5 GHz unlicensed bands (that's 5000 MHz); Clearwire is the second-largest owner of BRS frequency licenses and has leased additional licenses (some from Sprint/Nextel).

And I'm not even going to get into the butchering of OFDM, OFDMA, and FLASH-OFDM.

I do not pretend to be a professional analyst; I write about things that interest me. I have some knowledge from my day job, and I have half a dozen tabs open in Firefox as I write this to track down the rest. If I can get this stuff right, you'd think a professional analyst who gets paid to follow this stuff could.

Maybe I'm in the wrong line of work.

Saturday, August 06, 2005


I'm probably going to be unpopular for saying this (the blogger community tends to be rather anti-establishment, I find), but: I feel the FCC did the right thing in extending CALEA obligations to "interconnected VoIP service providers."

CALEA came about largely because of, believe it or not, ISDN. Unlike a traditional phone line, you can't wiretap an ISDN line. At one time, it was actually believed that ISDN would be widely adopted in the US (please, hold your laughter), and this would have a detrimental effect on the ability of law enforcement to administer authorized wiretaps.

Fast forward a few years, and there's a new problem for wiretaps; namely, cellular phones. Can't tap one of them, either. In my opinion, cellphones became the major impetus for CALEA continuing to move forward once it was apparent that ISDN was pretty much a non-starter in the US.

The intent (I feel like a Constitutional scholar, talking of "original intent") was to provide capabilities to law enforcement that would enable them to execute lawfully authorized wiretaps (and pen register trap and traces, but let's just stick with the term "wiretap" for now -- it's so semantically loaded) substantially equivalent to what they could execute on a traditional phone line, on "non-traditional" telephones or the equivalent. No more, no less.

So, along comes VoIP. Can't tap VoIP, either. Just as I dislike asymmetrical regulation, I dislike asymmetrical statutes - and requiring landline and wireless carriers to implement CALEA capabilities while not requiring VoIP service providers to implement equivalent capabilities is asymmetrical. Does it serve the public interest if a law enforcement agency gets a lawfully-authorized intercept order against a person, but is only able to execute that intercept if the person's phone is landline or wireless, not VoIP? I don't see it.

That said, I do have some problems with the way the FCC is going about it. For one thing, the FCC established a deadline of 18 months from issuance of the order. The original CALEA statute (passed in October, 1994) had a deadline of four years; the FCC eventually established a deadline of June, 2000 (five years and 8 months), and granted extensions to June, 2002 (over seven and a half years) to any carrier that asked. Seven and a half years for the industry to figure out how to make three-way calls and pen register traps transparent to the calling parties and easier to manage, versus one and a half years to establish entirely new technology for intercepting packetized voice transported over a broadband connection that may be owned and operated by a third party, strikes me as a bit (here we go again) asymmetrical.

It will be interesting to see how this plays out. The telephone companies enlisted the support of the telephone equipment manufacturers, defined a standard, played for time, and got the government to pay a significant amount of money to get compliance ($450M paid or owed as of 9/30/03). I don't know if the VoIP service provider community is as adept at the regulatory dance.

Clearwire Growth

Steve Stroh's BWIA/WiMAX site points to an article on Clearwire's ramping up for growth. The article uses, among other things, a perusal of internet job posting sites to project locations where Clearwire may begin offering service.

One thing that I've not seen anyone pick up on, other than discussing rumors, is that Clearwire has entered into a lease agreement with Sprint to lease 54 BRS licenses in 21 BTAs. It requires some digging through the FCC ULS database to get all the details -- and the work done to uncover them was sufficiently part of my day job that I'm not inclined to list them all here -- except to say that one of them is in fact call sign B050, covering BTA 050, Boise-Nampa ID (one of the cities mentioned in the Puget Sound Business Journal article), and if you look at the Admin data associated with that license it'll clue you in how to find the rest.

It seems to me that the FCC's recent actions are the best thing that could happen for broadband wireless access. Eliminating the requirement that cable companies and telcos make their local access transmission facilities open to other service providers virtually forces aspiring competitors to a wireless access approach (unless you think broadband over power line is viable, which I'm not too sure of).

Wednesday, August 03, 2005

FCC Approves Sprint/Nextel Merger

While officially the FCC only approved the transfer of control of spectrum licenses and leases from Nextel to Sprint, they're basically approving the merger, with very few conditions.

One condition, which will be of interest to the WiMAX watchers out there, is that Sprint committed to "offer service using BRS/EBS spectrum to at least 15 million Americans" (hmm, do they have to check passports of everyone in range of their towers?) within 4 years and to another 15 million within 6 years.

Of course, they can get out of this commitment if "circumstances beyond (their) control" prevent them from meeting it. Sort of like the circumstances beyond the control of SBC that prevented it from meeting a commitment it made to the FCC when it purchased Ameritech, to offer competitive local service in 25 markets outside its regions.

It is interesting to see the difference between the public safety obligations being placed on carriers in a mature industry such as cellular telephony and those being placed on service providers in an immature industry such as VoIP. As noted in Commissioner Copps's statement, Nextel will not meet the FCC requirements on cellular E911 until the end of 2007, two years after the FCC deadline. Not only is the FCC not requiring them to cut off service to their customers (unlike the guidance from the Enforcement Bureau given to VoIP service providers), it is not even imposing merger conditions related to E911 compliance.

Some would call this a double standard.