Are cable companies just being big bullies in the LTE-U debate? The Media Freedom's Mike Wendy thinks so -- and no, he's not being paid by Qualcomm (NASDAQ:QCOM) to say that.
"More specifically, Big Cable has been moving in overdrive to create fear, uncertainty and doubt around the proposed rollout of LTE-U (i.e., LTE cell services designed to operate over unlicensed spectrum to relieve cell site congestion) by the competitive mobile carriers, hoping that the FCC helps it forestall or squash this nascent technological competition under the guise of protecting Wi-Fi," Wendy wrote in blog post this week. He also posted this rather humorous video.
For the record, Wendy told me that while Media Freedom accepts funding from unnamed resources, it gets no funding from Qualcomm. As Wendy points out, LTE-U is a competitive threat to Big Cable because it will provide consumers with a better wireless service. That, however, doesn't come through in the public spin. "It's warning all who can hear that LTE-U will somehow interfere with Wi-Fi for everyone if and when it gets rolled out," he said.
Indeed, the day after Wendy posted his opinion, CableLabs coincidentally posted a blog explaining its position. "The fundamental problem here is that LTE-U does not "listen before talk," a most basic politeness protocol; instead, LTE-U 'listens and talks anyway' regardless of whether somebody else is talking or not," said Jennifer Andreoli-Fang, principal architect at CableLabs, in the blog. "Put another way, once the LTE-U node determines the duty cycle parameters, the coexistence spec allows the node to transmit uninterrupted for an undefined period of time regardless of other network traffic on the channel."
She reiterated the Wi-Fi community's support for LBT. "There seems to be consensus all over the world that LBT is a fundamental coexistence requirement. The cellular industry itself (3GPP) has explicitly rejected non-LBT based approaches to the LAA standard, and regulations in the EU and Japan require LBT," she said, adding that CableLabs encourages the LTE-U Forum to follow the 3GPP's lead.
What seems to really bug the cable community is the fact that Verizon (NYSE: VZ) got together with some vendor partners -- Alcatel-Lucent (NYSE: ALU), Ericsson (NASDAQ: ERIC), Qualcomm Technologies and Samsung -- and they developed LTE-U outside of any standards groups. That raised a lot of questions and suspicions. When I first heard about it, it sounded kind of strange, like they were trying to be deliberatively secretive. Since then, however, LTE-U Forum members explained they weren't being sneaky; they welcome input from others and even incorporated some of that feedback into their specs. They're holding workshops and meetings, but they don't like the idea of being told that whatever they produce somehow needs the blessing of the Wi-Fi Alliance; in short, they feel like their innovations are being held hostage.
More than one executive has told me they think the entire argument now boils down to an emotional one rather than something based on facts. Qualcomm et al. argue that the LTE-U Forum's version of LTE-U actually makes Wi-Fi work better, and they say they've been trying to be inclusive rather than exclusive.
But Rob Alderfer, vice president of technology policy at CableLabs who contributed to the aforementioned blog, said via email that the LTE-Forum is a closed, ad-hoc group of companies developing non-standard technology. "Unlike working in standards bodies, which have well-understood processes and means of contributing, there is no clear path for engaging with the LTE-U Forum," he said. "The use of shared unlicensed spectrum requires shared responsibility for development. The benefit of working through standards bodies is that solutions are developed, which become widely supported."
In one corner, you've got the cable industry and the Wi-Fi Alliance that are concerned about the future of Wi-Fi. In the other, you've got people who insist they are being innovative by figuring ways to make Wi-Fi work better. The whole thing brings up a lot of touchy issues. After all, it is the unlicensed band, and while you can't release something that's going to cause harmful interference, likewise, how can you hold the "innovators" back if, as they say, they're not going to interfere but actually make everybody work better?
While the Wi-Fi camp favors LBT, the LTE-U crowd says that's not really necessary. "The LBT spec is required in the 5 GHz band in Europe and Japan, but not in the United States or elsewhere around the world, and contrary to the quote from CableLabs, different technologies use different coexistence techniques in unlicensed spectrum," Dean Brenner, senior vice president of government affairs at Qualcomm, told FierceWirelessTech. "In fact, we have filed a mountain of test results proving that the CSAT coexistence mechanism in LTE-U works extremely well and ensures that LTE-U will not have any adverse impact on Wi-Fi." And by "mountain" of test results, I have no doubt that is true. Qualcomm showed off some of the test results to a group of journalists whom it hosted last month.
"Moreover, as we have repeatedly explained in FCC filings and in our extensive interactions with CableLabs, each LTE-U small cell scans the spectrum to find a vacant channel," Brenner said. "If there is no vacant channel, the small cell identifies and uses the least occupied channel. When the LTE-U small cell goes on that channel, it will listen to neighbors on that channel and only use the spectrum for a proportionate share of the time, ensuring that Wi-Fi nodes can access the spectrum for their proportionate share of the time."
Contrary to what CableLabs says, the maximum continuous transmission time in LTE-U set out in the LTE-U Forum specification is no more than 50 milliseconds, Brenner said. "During its operation, the LTE-U small cell periodically rescans the spectrum, again looking for a vacant channel or the least occupied channel, and repeats this process. From our extensive testing of Wi-Fi access points, we know that they often do not share spectrum fairly with one another even though they use LBT for coexistence."
Meanwhile, Alderfer also said CableLabs' focus is technology research, and "it is clear that the use of LTE in unlicensed spectrum poses a significant threat of interference to Wi-Fi and other unlicensed technologies. We do not think this problem is unsolvable, and we do not fundamentally oppose the use of LTE in unlicensed spectrum. It will take broad agreement on the right technology solutions, and our goal is to see unlicensed LTE developed in a way that enables all unlicensed technologies to thrive."
Verizon recently told the FCC that LTE-U is based on 3GPP's current standards of Release 10/11/12 and complies with the FCC's Part 15 regulations. Verizon says it and the LTE-U Forum have done extensive testing to show that LTE-U will operate in the 5 GHz band without causing harmful interference. And here's one you might not have expected a few years ago: "Verizon emphasized our longstanding support of unlicensed spectrum and our strong commitment to Wi-Fi," the operator said in its filing.
It's reasonable to think that Verizon and its partners are not going to create something that is going to mess with Wi-Fi since they all have a stake in it as well. But without more and more tests, no one is going to believe them. A lot of smart people believe the industry can find the solution without resorting to the FCC's further involvement; there's just a lot of bad blood getting splashed around in the meantime. --Monica