Re Gilder's comments - So you have a situation where the assignment of these specific frequency channels just no longer makes sense.
Rather than issuing spectrum licenses, they [should] issue driver's
licenses. Anybody can use spectrum as long as they don't interfere with other users or they don't exceed the speed limit - use too much power or pollute the environment by all sorts of uncontrolled frequencies.
Although I am loathe to disagree with one of Qualcomm's supporters, I think that this is perhaps a little optimistic. There are a variety of problems with this, and although its possible there might some way to work around them, it isn't immediately clear:
1) As he points out, if you have a free-for-all within the spectrum, then power must be rigidly controlled. But this requires some form of central control since an absolute level is not adequate. Without central control you run into the same problems that Qualcomm worked so hard to get around - the near/far problem. (Note that this may be workable by assuming that instead of using fixed bandwidth with variable power, you use variable bandwidth with fixed power level, but the technology for that isn't here yet in a practical handheld, nor is it absolutely clear to me that it solves the problem.)
2) Spectrum is, in fact, limited, although we may not hit that limit for a while yet. The problem is that even with CDMA the signals cannot be perfectly orthogonal since each of the transmitter/reciever pairs is located differently. Thus each signal, by definition, interferes with every other signal being broadcast from a different location. Thus, for any given amount of spectrum, there is only so much stuff you can pack into it. CDMA may be more efficient than most and there may be some that are even more efficient, but it isn't unbounded.
3) In order to take the full advantage of the spectrum that he talks about you really need to be able to have transmitters/recievers that are very flexible. Imagine you didn't have such flexible devices and someone else started transmitting in what is now Sprint's allocated spectrum. The installed hardware that Sprint has cannot just move to some other, less busy, frequency willy-nilly. It just isn't tuned for it. Thus, Sprint is just plain out of luck. In 15 years when we can control 1 or 2 GHz devices in software this becomes more practical, but as of now this would be very very difficult.
Again, I don't like to disagree with someone so eminent as GG, but... .
Clark
|
