Letters to the Editor
Some spectrum still needs protection
I am astounded, but not surprised, by the comments of Jock Gill in 'The spectrum debate is obsolete'. While there are some valid points identified, the ability to separate these points from the fear, uncertainty and doubt negates many of the arguments he presents.
David Reed's comments regarding quantum mechanics may be accurate, but he has apparently little understanding of the inherent noise levels present in all electronic devices, or of the relationship between frequency and propagation characteristics of a signal and its associated losses. The ability to receive any signal involves having a signal level above the internal noise of the device used as a receiver.
The current allocation of the spectrum was designed and agreed upon based on type of service, quality of service and propagation characteristics. Some radio services require significant protection from interference and degradation. For example, the emergency and life-critical communications functions deserve this protection.
These services require quality of service over specific areas that, based on wave propagation characteristics, have resulted in the specific frequency allocations.
Many of the nonsafety services could benefit from some of the technological approaches Gill discussed, but there are limits.
During the 1990s many spectrum slices were reallocated to benefit someone's vision of a connected society. Most of these changes have not proven to be of any value in proportion to the magnitude of the changes. Take, for example, the spectrum auctions intended to bring money into the treasury and provide spectrum for the new telecommunications providers. More than half of the auctions failed and resulted in default to the government.
The money from those auctions was supposed to pay for the new equipment the government would require as a result of selling a portion of the spectrum. The money never arrived and the taxpayer had to pick up the expense for something that benefited only a few.
More serious is that the new services were cherry picked'aimed at major metropolitan centers. The rest of the population didn't receive fair value for the sale of the frequencies and resulting loss of services.
I firmly believe that the spectrum required for adequate defense of the nation and life safety services is more important than some people's desire to pollute the spectrum for their own limited commercial exploitation.
The radio frequency spectrum is considered by many in IT as just another medium. But RF has significant limitations'including the laws of physics.
Hopefully someone will recognize this and come up with valid proposals based on full consideration of the many uses of the spectrum.Donald Smith
Huntsville Operations Manager
Modern Technologies Corp.
Huntsville, Ala.Physics of bumblebees
After reading and digesting Jock Gill's column, I must point out a very basic, but extremely important, distinction regarding the statement, 'Radio waves simply don't interfere.' The distinction: It is not the so-called collision between radio waves which causes interference but the receiver getting an unwanted signal with enough power to override or hide the desired signal.
Think of what happens when you are driving a car between the overlapping coverage areas of several FM stations, and notice how the station you are listening to is slowly overwhelmed or replaced by the increasingly closer and stronger station.
At no time did the electromagnetic waves collide, but the desired signal was replaced by the greater power of the undesired one.
I have no real knowledge of quantum mechanics, but I do know radios get interfered with. I also believe analyses that conclude bumblebees shouldn't be able to fly, but don't tell the bees that.Chris Lewis
Office of the CIO
Treasury Telecommunications System Division