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.
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.”