NewMax Vs xMax

There's an interesting post over at Brough Turner's Blog HERE. He's an acknowledged radio expert who seems to know his stuff. Back in 2006 he had much the same conclusions as Phil Karn that to work as they then claimed xMax would have to violate physical laws, and/or FCC regulations. Then the claims were of 10,000 times less power than other systems for the same data-rate, cities covered with 4 basestations, and networks run on watch batteries. It was madness. To make matters worse the company was promising an imminent launch of this impossible system: The R&D is over said Mooers in March 2006 "We’re at the commercialization and product stage now." The launch was promised before the end of 2006, with 4G networks coming shortly after. Well, that went well.

This obviously made them a laughing stock and exposed the ridiculous lack of knowledge (like the Shannon Bound) of basic communications theory of the inventor Joe Bobier, and the psychotic optimism of Arsehole Rick Mooers. The fact that xG were touting for investors to buy shares in an invention that couldn't possibly work was fraud pure and simple. And they could never claim they were ignorant of this: Karn told them, I told them, it was all over the Internet.

Then, somehow, Joe seemed to have been introduced to the real world. This culminated in the FCC certification of BSN250. This was a basestation that seemed to use perfectly ordinary modulation methods. Nothing spectacular. Nothing unusual. Boring, but it would at least work.

The problem with that is twofold
1) Investors were promised a Ferrari, xG unveiled a bog standard hatchback. It was the most outrageous misrepresentation.
2) Nobody thought of telling the stockmarket that xG's only product had changed 180 degrees in violation of many stockmarket regulations.

To xG's credit they have used this conventional radio modulation system to make a network. Gone was the Wavelet Pass Filter which Bobier and Schwartz had claimed was the "key to xMax", which meant that interference was 'eliminated' (unless you were conducting a xMax demo obviously), and in was a conventional system that switches frequency many times a second.

In July 2010 Brough actually went to visit Joe to see the system. As we imagined the modulation was standard, and running at 2G speeds, not the 4G promised four years ago. There's nothing special. Most fascinating for me though is an entry in the comments:

Brough

Thanks for the fair overview of where xG is today. It did take a reinvention of the company to move into our new direction of offering carrier class cognitive radios. Hopefully we can get this technology into the standards at some point.

Rick Rotondo
VP Marketing
xG Technology

That, to me is incredible. He's admitted the bait and switch - The 'reinvention'. He's as good as said what they have now is a standard modulation, not the amazing low power/high data rate modulation they were flogging initially. The system around it may be cute, but there are many other cute systems out there.

I'll email Mr Rotondo to comment here. I wonder if he will.

Edit: Surprise! No news from Mr Rotondo. There's another blog over at 4G Wireless Evolution that mentions xG. Carl Ford says:

The chip makers for WiMAX are all finding their way into LTE - mostly through Time Division over Frequency Division, which according to our friends at xG Technology, is a secret sauce that will allow beam forming and cognitive radio to live in noisy spectrum.

TMDA and FDMA (Time and Frequency Division Multiple Access) are fairly common among modern radio systems. The 'Key to xMax' - the wavelet pass filter - is gone. The incredible modulation is gone. And so is the $1.5Bn valuation.

Don't look at the man behind the curtain. Move along, nothing to see here.