My guess is that I don’t need to use the S-word at all; that it can be replaced with simple terms rather than clumsy paraphrases; and that the clarity of a text, and the understanding of the reader, will be greatly improved if one avoids it.
I first raised this possibility in the DySPAN 2008 paper De-Situating Spectrum: Rethinking Radio Policy Using Non-Spatial Metaphors where I recommended a “restatement of wireless policy in terms of system operation rather than spectrum.”
The word “spectrum” has many meanings, depending on context. In policy documents it’s usually short-hand for the topic dealt with by radio regulators, aka their “the object of governance”. There are a range of intended meanings, including a radio license; a range of frequencies; or all the parameters (frequency, geography, transmit power mask, allowed use, single or paired bands, etc.) associated with a radio license.
Engineers use “spectrum” to refer to a range of frequencies, or sometimes to electromagnetic phenomena. Less frequently – curiously, since this is closest to the dictionary definition – they use it to refer to the distribution of electromagnetic energy that results from radio operation.
In short, the following substitution covers most cases:
FOR spectrum SAY radio license OR radio operation OR frequenciesThe S-word is also used in various combinations; here are some translations:
FOR acquire spectrum SAY acquire permissionsThe value of more precise terminology becomes obvious when one looks through this list. One can distinguish between two distinct referents of “spectrum”: the parameters of operation of radios, and the rights to operate. It’s a distinction between assets and operations. One can easily put radio licenses (“spectrum”) on a balance sheet, but not the institutional and technological ways of coordinating radio operation (“spectrum”).
FOR sharing spectrum SAY coordinating operation
FOR use of spectrum SAY operation of radios
FOR spectrum rights SAY rights to operate
FOR spectrum allocation (noun) SAY license type
FOR spectrum allocation (verb) SAY deciding use
FOR spectrum assignment (verb) SAY authorizing a radio operator
FOR Dynamic Spectrum Access ("DSA") SAY dynamic radio operation
FOR stockpiling spectrum SAY stockpiling licenses
FOR demand for spectrum SAY demand for licenses
FOR manage spectrum SAY manage radio operation
FOR improve the efficiency of spectrum use SAY increase concurrent radio operation
FOR a chunk of spectrum SAY operations concentrated in a band
But why bother? An obvious retort is that this is just nitpicking: “Everybody knows what they mean by the word in a given context.” I argue that it’s important because the connotations of words matter, and change how we see the world.
Constant, thoughtless use of the S-word without teasing apart its meanings creates a thing: “the spectrum”. We come to accept as real the illusion that we’re dealing with a concrete thing (like bushels of corn) rather than the behavior of devices and their owners. If one takes away the radios, “spectrum” as an object of governance ceases to exist, although “spectrum” in the sense of “electromagnetic phenomena” persists. This illusion leads to the fallacy that “spectrum” can be counted like bushels of corn, whereas it is in fact a regulated socio-technical arrangement. It leads to the fallacy that “spectrum” can be counted, and that it is permanently divisible and inalienable.
I’m not denying that interference can occur between radio systems, nor that property rights can facilitate the coordination of radio operation. Rather, I’m suggesting that “spectrum” leads too easily to important conclusions that need to be considered more deeply, such as that wireless licenses are necessarily exclusive rights to operate in fixed frequency ranges. A focus on the behavior of radio systems, which changes constantly as technology and institutions evolve, rather than some spectrum-as-thing can produce a more robust and efficient way to coordinate radio operation.