Of all the companies I’ve written about during the past several years, none of them have created as much of a stir as xG Technology, the Florida-based startup that has earned a host of patents for wireless technology breakthroughs and criticism from many on the Internet, claiming that the company was overhyping its solution.

Those blogosphere debates aside, here’s the bottom line: xG has deployed test networks in Florida and Arkansas that deliver mobile VoIP calls over spectrum in the unlicensed 900 MHz band. And respected third-party observers — not just company officials — are saying the xMax system works.

Two of those observers who have seen firsthand xG Techology’s five-site, 32-square-mile system in Florida are Akshay Sharma, research director in the carrier network infrastructure group of Gartner Research, and mobile wireless consultant Andrew Seybold.

Both have visited xG Technology during the past few weeks, and both were admittedly skeptical after reading some of the criticisms of the company on the Internet. However, both came away impressed with xG Technology’s Florida network after testing it.

Sharma noted that the voice quality was carrier grade, saying he “did not notice any noticeable echo or jitter” in the calls he made on the network. Sharma said he purposely visited a location with heavy unlicensed 900 MHz traffic to determine whether the higher noise floor would create problems with an xMax, and the call quality was unchanged.

Of course, the idea of delivering carrier-class voice calls without having to spend big bucks to buy licensed spectrum is a monumental notion. Seybold said he was impressed by the Florida but stopped short of saying that any large-scale commercial wireless system using unlicensed spectrum can compete with the networks operating on licensed spectrum. Sharma said he would like to see the network perform with more xMax users in a given cell sector to determine whether it can scale in the manner needed in a commercial network.

However, of all the unlicensed solutions he has seen, Seybold said the xMax technology “has the best chance” of deliver quality-of-service levels that carriers offer routinely.

Meanwhile, xG Technology officials are considering markets beyond the commercial sector. The company is able to avoid interference in the unlicensed band by using cognitive-radio technology, which is something the military has been researching heavily in recent years.

With this in mind, new COO John Coleman — a longtime Marine familiar with military procurement procedures — has opened some doors that have allowed military personnel to see the xG Technology solution in action. A recent demonstration of the technology left military officials with “their jaws on the floor,” Coleman said.

Exactly what comes of this is anybody’s guess, as there are lots of technical hurdles and business realities that must be addressed before any soldier will be communicating over an xMax network. However, since seeing the xMax technology years ago, I’ve been intrigued by the potential of xG Technology’s frequency-agile, low-power solution to serve both military and public-safety needs. Hopefully, some people with proper credentials will take a look and determine if xMax can help first responders both domestically and abroad.

What do you think? Tell us in the comment box below.