From Arthur S. DeVany and others.
One possible way to take explicit account of the unpredictable variations in field strength is to devise a stochastic definition for the spectrum-use property rights. For example, an operator could be permitted to exceed the field-strength limit (X v/m) in adjacent areas by up to 10 percent during 15 percent of the time he transmits.
The problem is that your cow could randomly walk from your field over the edge into my field. If I insist that any intrusion is a violation, then you have to keep your cow well inside your field, effectively reducing the size of your field. A stochastic definition of my property rights could allow your cow to come 10 percent into my field 15 percent of the time without penalty. In the end, though, the authors think that a stochastic definition is not better than a fixed definition. I would agree. To me, it seems that under the stochastic definition, the size of my field has been effectively reduced, because I cannot be sure that my crops near the edge won’t be trampled by your cow.
Later,
intermodulation interference occurs in a third frequency only when the frequency equals either the sum of the other two frequencies or their difference.
I do not know with modern technology how important this is. If it is important, then authors propose a rule for assigning liability for such interference, and that rule puts the burden on the owner of that transmitter to negotiate a solution. Again, I have no idea where that solution is practical in today’s environment.
Still later,
require that all agreements by TAS [Time/Area/Spectrum] owners relating to the use of spectrum be recorded in a central registry.
This is analogous to having property deeds recorded in a central registry, such as the county recorder’s office. Right now, the FCC has to manually approve every transfer of spectrum. In a true spectrum market, the FCC might be responsible for maintaining the database, but private parties would not require approval for spectrum transfer. TAS means that what you own is the right to use at a particular time (which might be 24 hours a day) in a particular area a particular band of spectrum.
On the one hand, I am very pleased to see detailed specifics in their proposal for spectrum property rights. On the other hand, I worry that over fifty years later some of the analysis needs to be redone.
Technology has changed quite a bit. The key idea is that signals have a point of origin. Two signals even on the same frequency can coexist even if the path of the signals crosses. Compound attennas allow receivers to sort this out, selecting the signal coming from the correct direction. This works particularly well at high frequencies. eg 2.4GHz abd modern electronics makes working at high frequencies easy. So spectrum regulation is gradually becoming obsolete.
Have you seen any discussion about the way international shortwave bandwidth is allocated? Obviously there’s no central authority, so broadcasters voluntarily allocate frequencies and times at semiannual meetings.my dad went to these four years, so let me know if you want to ask him about it.
There must be an allowance for stochasticity. Everything is stochastic. Only government rules that out. You cannot hold someone guilty of trespass if variations in the troposphere alter signal paths. One could have a boundary, as you suggest. That is like having a “fuzzy fence” on your property. Since that means a probability density function at your boundary, it is a matter of the probabilities that one agrees to.
To take the point another step, there are no freqency allocations. They are all probabilistic. That is our world too. Thanks, Arnold for this post. That was my very first journal article. I never thought it would become a classic.
And, the other point is that intermodulation interference is really a problem with the receiver’s receiver. It is easily designe out, were it important. Intermodulation is simply a non-linear response of the receiver and not properly understood to be a violation
of issuer’s property right.