Monday, August 29, 2011

Spectrum “sharing”: the convenient ambiguity of an English verb

I realized while writing Spectrum Sharing: Not really sharing, and not just spectrum that my confusion over the meaning of spectrum sharing derives from two meanings of the English verb "to share":
(1) to divide and distribute in shares, to apportion;

(2) to use, experience or occupy with others, to have in common.

For example, the first is sharing a bag of peanuts, and the second is sharing a kitchen or an MP3 file. Cellular operators and economists tend to use the word with the first meaning, and Open Spectrum advocates with the second.

But that raises the question: is the double meaning inherent in the concept, or is it just an accident of English vocabulary?

I asked some friends about the regulatory terminology in other languages; so far I have information about Arabic, Chinese and German. If you could shed light on regulatory terminology in other languages, for example French, Japanese or Spanish, please get in touch.

I learned from Dr. Fadel Digham, R&D Director of the National Telecom Regulatory Authority (NTRA) in Egypt, and Mr. Mohamed El-Moghazi, Senior Manager, Spectrum Research & Studies at NTRA, that there are two different words/definitions in Arabic:
mokasama (مقاسمة): distributing things in non-overlapping shares given fixed boundaries. This is the term used in Egyptian regulation when dealing with spectrum; although the exact word is not used, the definition itself is included as the basis of assignment. Fadel Digham observes that in the networking literature, the term time-sharing is used to indicate sharing across time (not simultaneously sharing some resource): TDMA. Likewise, frequency-sharing is synonymous with FDMA. So, both time-sharing and frequency sharing in network and communications literature belong to this denotation.

mosharaka (مشاركة): having common access to a certain resource/utility, e.g. sharing a room. The term is used by NTRA to denote site sharing (the same site used by different operators to install their equipment), duct sharing (laying down different cables in the same duct), and the like. It is not used in the spectrum context; if it were used there, it would imply either concurrent access, or a common pool of frequencies (perhaps something like Wi-Fi).

A Chinese-speaking wireless researcher informs me that there are two popular translations for sharing:

fen(1) xiang(3) (分享): usually used for sharing a file on the internet, for sharing your food, etc. It means sharing a mutual space/item without defining a clear boundary/allocation.

fen(1) pei(4) (分配): allocation; usually used for spectrum, meaning distributing spectrum for exclusive usage across service providers.

This colleague reports that Chinese regulators use the second word (fen(1) pei(4) 分配, exclusive usage) even for the 700Mhz spectrum they plan to release by 2015. Chinese translations of “sharing” always use 分配.

Courtesy of Petri Mähönen at RWTH in Aachen and a German-speaking colleague, I understand that German regulators have a number of different terms for "sharing":

Zuteilen: to slice and point out who retrieves ownership, i.e. "allotment" (see below).

Aufteilen: just 'slicing' spectrum, but does not necessarily imply anything about the ownership of the "slice".

Verteilen: the act of handing objects to a group of people, in English closest would be to "distribute", or "to share".

Teilen: slightly different from verteilen, with the connotation of a lack of hierarchy, a bit of "socialism". In this case there is usually no third party involved that is a decision maker, as when the kids share candies among themselves. (If mother needs to do it, it is more like verteilen.)

Anteilige Nutzung: using a part of the bigger thing, a kind of shared commons use.

Exploring the terminology of the German telecommunications act, I gather that the first step is Frequenzbereichszuweisung, which is the allocation of allowed types of services for a frequency band. Then follows Frequenzzuteilung – here we see the zuteilen part – which is assigning spectrum to a specific use and specific operator. The verteilen is done in the Frequenznutzungsplan, which I understand to be the designation of coexisting uses in a band, e.g. TV transmitters and wireless microphones. A frequency band under Allgemeinzuteilung (allotment to general use, similar to Part 15 in the U.S.) does not need a license. In short, German usage makes a distinction in the terminology of sharing between apportionment (zuteilung) and in-common use (verteilung).

Overall, it seems that the English ambiguity between sharing-apportion and sharing-in-common is unusual, and not seen in some other important regulatory nomenclatures.

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