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T-Mobile Claims, FCC Tests
Friday, 10 October 2008 18:22
With $billions at stake, companies often stretch the facts.  Lawyers in the U.S. system are expected to advocate strongly, with an opposing lawyer expected to bring issues closer to the truth.  Engineers, economists, "independent analysts," and "non-profit groups" are expected to present the truth as best they can. In practice, in D.C. you can find an economist willing to testify to almost anything for an appropriate fee. Some are distinguished university professors who back up work with logic they wouldn't accept from a beginning student. Others are blind to their biases, particularly "keeping government out of things is good."  Some make honest errors and find their opinions magnified enormously by the lobbyists, overwhelming the truth. (Think "publication bias.")

The FCC has just demonstrated that some engineers come to unsupportable conclusions on behalf of their clients.  Milo Medin and John Muleta's M2Z wants to create a wireless network across the U.S. in the 2155-2175 band with an offer to make low speed use free across the country. That would be a good thing, especially if they keep the latency low enough to use for free VOIP calls. 

T-Mobile did what so many others do, and "submitted into the record test results which it claims shows that under the proposed
rules, harmful mobile-to-mobile interference is likely to occur." T-Mobile presented an argument persuasive enough non-technical observers didn't see the fallacy. Fawn Johnson of the WSJ didn't find enough information to detect the fraud. "Until the engineers' report on Friday, T-Mobile and M2Z had offered widely different views of the results." She would have written differently if she knew the T-Mobile claims were invalid.

The Right Response: Find the Facts

The FCC engineers understood what was happening, however, and followed up by doing something very sensible: finding the facts.  "Commission staff, together with interested parties, performed laboratory bench tests to investigate this interference potential."  The tests were "open to the public and conducted at Boeing’s test facility in Seattle Washington." They used a "test setup identical to that described in the T-Mobile Test Report." The conclusions "support allowing power levels of up to 23 dBm/MHz and an OOBE limit of 60 + 10*log(P) dB."  The OET claim to that conclusion using T-Mobile's methods, while repeatedly pointed out that T-Mobile methods "will tend to overestimate the interference." They added "tests generally show that a WiMAX signal [the proposal] has less potential for causing interference than a UMTS signal. Based on these observations, we can reasonably expect that WiMAX in the AWS-3 band would have less impact on an AWS-1 receiver than UMTS."

OET also observed "in actual operation under non-static conditions, the situation only improves. ... [More realistic assumptions result] in a vastly reduced interference risk. Similarly, our analysis assumes an AWS-3 handset transmitting at its maximum power, which will occur only a small portion of the time;25 a reasonable assumption especially if AWS-3 signal patterns are similar to
those cited by T-Mobile in their Test Report.26 This too would reduce the interference potential predicted here. In addition, we note that modern wireless phones operate across multiple frequency bands and channels. Our static analysis only considers the case where the AWS-1 and AWS-3 handsets are operating on directly adjacent channels and in close proximity. Under likely scenarios where this is not the case, the potential for interference would be reduced from that predicted in this report."  Those scenarios result "in fewer instances of interference than would be predicted by this static case."

Looking at comparable problems elsewhere is often a good way to get at the truth. I knew Bell Canada's claim of serious congestion problems in broadband resembled a week old fish because AT&T, Verizon, and British Telecom didn't have similar problems with very similar networks and often identical equipment. OET looked to Britain's regulator, discovering "The situation analyzed by OFCOM is very similar to the situation we are considering here, although there are some differences. OFCOM determined that TDD and FDD mobile handsets can operate in adjacent bands with appropriate technical constraints."

The Incentive For Incumbents to Fight So Hard

The dominant U.S. carriers have spent tens of $billions at auctions to keep out competitors. They are reaping very strong rewards. Wireless calling costs in the U.S. have actually gone up 11% in the last year, by BofA's respected analysis.  Since Nextel and AT&T Wireless were bought out, U.S. mobile customers are paying more.  Post hoc isn't propter hoc, but the transformation is dramatic. If the historical drop in rates had continued, the carriers would have collected $10B to $25B less.

U.S. mobile pricing is consistent with a reasonably effective cartel. As far as I know, that's policed by publicly creating market conditions, not by any secret conspiracy. In a recent example, Verizon and AT&T publicly indicated they would beat down Sprint if they cut. The message was heard, and Sprint only made slight changes in a few expensive plans few people use.

Each additional network enhances security after a disaster, as Ken Ferree eloquently explained after the World Trade Center and Pentagon were hit. I was near the Pentagon that day, unable to get through to Jennie in New York by phone. Fortunately, a hotel datalink stayed up, allowing me to email her I was fine. I believe enhanced security should have been enough to ensure the buildout of WiFi across U.S. cities, but that redundancy was not recommended the "FCC Independent Panel Reviewing the Impact of Hurricane Katrina on Communications Networks." The panel was headed by Nancy Victory, who represents Verizon at Wiley, Rein.