xG Technology demonstrates xMAX
FORT LAUDERDALE, Fla. — Despite being faced with logistical complications caused by Hurricane Wilma, Florida-based xG Technology twice demonstrated last month the long-range capability of its xMAX solution, transmitting a data stream capable of high-quality video 18 miles using low power levels.
In the Nov. 10 demonstration, xG transmitted a 3.57 MB/s data stream on 10 MHz of spectrum in the unlicensed ISM 900 MHz band using just 35.8 mW of power from its omnidirectional whip antenna on an 850-foot tower to a patch antenna on a 12-foot mast. The off-the-shelf antennas combined for 14 dB gain.
“The message is: It’s real,” Chris Whiteley, xG Technology’s vice president of business development, said. “It really works, and it’s so big that we can’t get our brain around it.”
Indeed, the notion that an entity could become a broadband wireless provider without investing in any spectrum is compelling, especially when xG officials say the company’s receiver — the key to the solution — is “simple” and can be built “dirt cheap.” As a result, an xMAX system can be deployed much more cheaply than networks using other technologies.
“It reduces the costs of deploying broadband services; it finally makes it affordable,” Whiteley said. “It changes the economics, and it’s been the economics that have slowed the deployment of broadband services.”
And the data rates achieved in the demonstration are “as bad as it gets” for xMAX, said Joe Bobier, xG Technology’s president of operations and inventor of xMAX. No carrier signal — which would have required 6 kHz of dedicated spectrum — was used, reducing the data rate by about 25%, he said. In addition, many common techniques to improve performance were not used in an effort to keep the demonstration as simple as possible, he said.
While one Internet report described the Nov. 4 demonstration as a “low power/long range shot heard round the world,” many industry observers question whether xMAX is vastly superior to other modulation schemes. Princeton professor and IEEE fellow Stuart Schwartz said he understands the skepticism.
“There are still things they have to overcome: they have to try it in an urban channel, they have to try it when there are interferers around, and they have to try it in a multi-user environment,” Schwartz said. “[But] I thought it was a fairly impressive demo.”
And xMAX has plenty of room to grow. Whiteley noted that xG used just 10 MHz of the 26 MHz of spectrum available in the ISM 900 MHz band; using the entire band would result in a commensurately faster data rate. In addition, Schwartz said there is no reason that xG should be compelled to operate at such low power levels.
“It’s true, they covered 18 miles of swampland, and it was essentially line-of-sight,” Schwartz said. “But, don’t forget, they [used less than] 50 milliwatts. They can use up to 1000 milliwatts [without violating FCC rules]. So, if you are in an urban area, and you want to send it toward Miami, you boost up your power. And, because you’re using lower frequencies, it goes through buildings better.”
No in-building demonstrations were conducted, but Bobier said xG has run in-building tests with a rudimentary receive antenna on the interior of hotels and other buildings along the beach in Fort Lauderdale about 7 miles from the tower.
“When we were testing, we were in the middle of those buildings at the ground level and were getting an incredibly strong signal … [with a power level of] close to 200 milliwatts,” he said. “We almost had too much signal; it was almost saturating the receiver, there was so much signal.”
If proved to realize the lofty promises made by xG, the Flash Signaling technology at the heart of xMAX will have a “revolutionary” impact on the communications industry, said Rick Mooers, xG Technology CEO (MRT, September, page 40).
While the notion of inexpensively entering the wireless broadband ISP market is compelling, the technology also promises to let current spectrum owners reuse their airwaves. For instance, Whiteley noted that a public-safety agency with an 800 MHz voice system could use xMAX to provide high-speed data over existing spectrum without interfering with the voice system.
“What that would do is … give you two sets of networks,” Whiteley said. “And that’s important for service providers that don’t want to scrap their whole network but want to transition into it. That holds true for coaxial cable and phone lines, as well; you can send a second information-bearing signal without disrupting the current use.”
Although the long-range, fixed wireless application was demonstrated, xG’s signaling technology also can be used at shorter distances. In the lab, xG has transmitted a data stream of 2 MB/s over a distance of 40 feet using just 3.16 nanowatts of power, Schwartz said.
Mooers said xG has secured the funding it needs through early 2007, including an initial commercial rollout during the second half of 2006. Meanwhile, Mooers said he continues to seek large partners that are better positioned to commercialize xG’s solution, as well as help the small company deflect potential regulatory and legal threats that could undermine efforts to get the technology to market.
In pursuit of such an arrangement, Mooers said xG has signed letters of intent or non-disclosure agreements with Intel, two smaller chip manufacturers and Microsoft, although Microsoft has not reciprocated as of press time. In addition, xG has had discussions with Cisco Systems, Apple Computer and several investment banks, he said.
