A trip down memory lane

Pre – xG Technology


  • 3/2000
  • 6/2000
  • 9/2000
  • 12/2000 ” … Jeff Bobier, director of operations, said, “We could not be more pleased with the level of excitement that our Wish wireless product has generated. Our client partners are delighted with the progress of the deployments in Florida and across the US.””
  • 2/2001
  • 1/2002
  • 2/2003 “… Karason said he found out later that the whole demonstration was fraudulent, “using illegal power, illegal equipment, preloaded stuff on computers that we were told was downloaded over the system, etc., and in fact the Icelandic system did not work at all, as the people running it found out after the presentation — when the ‘magic dust’ had disappeared.””
  • 4/2004 “Surviving Smear” (contradicts some of the information stated in the 2/2003 item)

Finally, an interesting article from the early days of xG Technology 4/2003. Note that

“A small startup claiming breakthroughs in phase-coherent filter modulation will be demonstrating its signal-processing techniques in analog pager bands later this year, as a prelude to offering its technology for a range of wireless and wireline networks.”  “Bobier previously presented details of his work at the Telecommunications Industry Association’s Ventures 2002 show last July. At the time, Bobier claimed that analog paging channels would be able to transmit data at speeds of up to 150 Mbits/sec. He also began work last summer in reducing a typical TV transmission channel for coaxial cable from 6 MHz to 30 kHz.”

In other words he is talking about a spectral efficiency of 200, even bigger than that of Ultra Spectral Modulation (USM) who were going to demonstrate spectral efficiency of “only” 100! (Such a system would require an SNR greater than 600 dB.) Unlike Walker of VMSK fame and the USM folks he apparently managed to get rid of this particular delusion (xMax has a spectral efficiency on the order of 1 which is of course feasible). So he is learning, but still has some fundamental misconceptions about signal and systems, filters, and communication theory as will be immediately recognized by any competent communication engineer reading his patents.

Aren’t there any competent communication engineers on the xG team who could teach him this basic stuff? Or are they carefully hiring people who will not challenge the founder? Surely when they tested their systems he must have realized that the performance claims they have been making all along are based on serious conceptual errors (as xG’s own BER curve shows), not unlike the errors leading him to try and develop a system with spectral efficiency of 200! There is so much to learn in order to put together a working wireless network, and so little time …


5 responses to “A trip down memory lane

  1. Just out of curiosity… Part of xg’s explanation for their unwillingness to have the technology independently verified has been their concern over IP theft. Now they claim to begin rolling out and delivering handsets ot he general public. In your opinion; how long would it take some skilled person to reverse engineer the “magic filter” given access to a handset?

  2. JimDeGries@gmail.com

    The “magic filter” is discussed in detail in one of the patents – see the end of my post on “A little knowledge is a dangerous thing.” There is absolutely nothing special about it and no competent communication engineer would need to or want to reverse engineer it. Also, to the best of my knowledge there is no interest in xMax in any of the serious wireless companies. As I keep saying, anyone with competence in wireless communications who hears this story will dismiss it out of hand. A skilled person would most certainly not spend time reverse engineering xMax. At most they will measure a BER vs. Eb/N0 curve and verify that nothing unusual is going on (or they can just look at the curve published on the xMax web page instead).

  3. I guess you’re right. I was just so depressed by your bedtimestory and the fact that even in the face of evidence and reality these companies still exist (even at reduced market values), people still spend time on them and I’m sure they inspire others.

    I guess I was just looking for some kind of closure seeing how reason and science won’t do the trick for some people.

  4. JimDeGries@gmail.com

    Well, if you really want to get depressed you should look at the various perpetual motion and free energy claims. Wireless is a somewhat arcane technology, but you would think that people should know more about energy, engines and so on. Look at crank.net or my recent favorite, the Carl Tilley Foundation.

    I must emphasize that xMax is not in that category, because it is in fact a viable modulation technique that should (and apparently does) work. It is just that its performance is no better than that of alternative existing communication systems. This is very different from proposing to build something that can not work at all. It should be feasible to build a wireless network using xMax, which would work almost as well as a network which uses some other standard modulation technique. So perhaps you should not be depressed about xMax, just cautious. It is indeed worrisome that the inventor of xMax was apparently trying to build a communication system with a spectral efficiency of 200, but perhaps he learned from his mistakes.

  5. JimDeGries@gmail.com

    Another article I meant to include above:

    Idigi has tough time keeping its customers
    Published on January 30, 2002,
    Sarasota Herald-Tribune (FL)

    Perry Corneau says he made a mistake in December when he purchased Internet service from Idigi Communications. He bought into the company’s claim that it offered high-speed access at affordable rates. After the service was hooked up, Corneau says, it was no faster than his dial-up modem. “I could stick a broom out the window and it would have worked better,” he said. Corneau isn’t the only one complaining. …….

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