Dynamic spectrum access

Although all available spectrum is currently allocated in developed countries, many independent studies have found that the total amount of spectrum in use at any one time in any one place is a tiny fraction of the total.

Digital dividend and TV white spaces

[img_assist|nid=14227|title=Figure 4|desc=An example of TV channels adjudication in two cities that are close enough in proximity such that transmissions from one can reach the other.

Broadcasting

As the number of tablets and smart phones grows, telecom operators vie for access to new frequency bands, but the traditional methods of adjudicating the spectrum are facing limitations.

Keep in mind that the spectrum is used for radio and television broadcasts, for satellite communications, for airplane traffic control, for geolocation (Global Positioning Systems – GPS), as well as for militar

Political issues

Figure 3: The “spectrum Police” at work in JakartaFigure 3: The “spectrum Police” at work in Jakarta

The importance of spectrum as a communications enabler cannot be overstated. Television and radio broadcasting have a strong influence in shaping public perceptions on any issue, and have been used overtly for political propaganda.

Beauty contests

The “beauty contest” method requires interested parties to submit proposals on how they intend to use the spectrum. A committee of the spectrum regulating agency then decides which of the proposals better serves public goals.

Auctions

The two most popular means of granting access to licensed spectrum bands are through spectrum auctions and through so-called “beauty contests.”

The auction method is straightforward: interested parties bid for a given spectrum band; whoever commits the higher sum gets the right to use the frequencies.

New opportunities for internet access

The turning point, however, came in 1997 when the Institute of Electrical and Electronics Engineers (IEEE) approved the 802.11 Standard, the basis of what is now known as WiFi.

Unlicensed spectrum

Figure 2: A special vehicle for spectrum monitoring in Montevideo, UruguayFigure 2: A special vehicle for spectrum monitoring in Montevideo, Uruguay

Although the main use of spectrum is for communication purposes, there are also other uses such as cooking food in microwave ovens, medical applications, garage door openers and so on.

Spectrum efficiency

Figure 1: Cellular sharing of spectrumFigure 1: Cellular sharing of spectrum

Besides issues of national sovereignty defence, very strong economic and political interests play a determinant role in the management of spectrum, largely due to the rapidly increasing economic value of spectrum.

Spectrum sharing

Our understanding of spectrum has changed a great deal since Marconi first spanned the Atlantic with his “wireless telegraph message”. In 1902, he used the whole spectrum available at the time to send a few bits per second over thousands of square kilometres.

The spark transmitter used for Marconi’s telegraph occupied all electromagnetic frequencies available to existing receivers.

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