Dispositivi "white spaces": la FCC pronta ad approvarli

Potrebbe essere uno dei primi esempi reali, applicati di radio cognitiva. Si discute da parecchio negli Stati Uniti se autorizzare o meno l'uso non licenziato di dispositivi radio in grado di utilizzare le frequenze negli "spazi vuoti" i white spaces, tra i canali televisivi occupati dalle stazioni televisive digitali terrestri nella banda UHF. Oggi questa banda viene utilizzata anche dai broadcaster e da altri organismi (per esempio sportivi) per i collegamenti dei microfoni professionali senza-fili. E sono proprio questi ultimi player a nutrire grande diffidenza nei confronti di un utilizzo alternativo basato su tecnologie di "sensing", di rilevamento automatico. Il dispositivo non licenziato dovrebbe esplorare la banda televisiva, individuare gli "spazi vuoti" di una determinata area e autoconfigurarsi per la trasmissione e la ricezione in quegli spazi. I broadcaster sono addirittura inviperiti per il possibile ingresso di utenti non licenziati in un dominio superregolato come quello televisivo.
Qualche giorno fa il capo della FCC Kevin Martin ha ufficialmente sponsorizzato le istanze dei fautori di questi dispositivi, rappresentati dalla Wireless Innovation Alliance. Martin ha convocato una seduta che voterà sulla proposta il prossimo 4 novembre, mentre la FCC ha già reso noto un approfondito studio di fattibilità (trovate tutti i riferimenti nei link raccolti qui sotto dalla società di consulenza di Robert Gonsett, alla cui newsletter ho già attinto parecchio in passato. Io aggiungo la documentazione che ho trovato sul sito della Wireless Innovation Alliance, con un comunicato stampa riassuntivo e un riferimento al dettaglio delle richieste presentate alla FCC, e un pezzo della Associated Press che fa la cronaca delle dichiarazioni di questi giorni.
Tanto per essere chiari, dietro la WIA e la White Spaces Coalition, che propongono l'uso di questi dispositivi intelligenti e chiedono il permesso di condividere la banda con l'industria della televisione, ci sono aziendine come Microsoft. Tra gli oppositori, invece, segnalerei la Maximum Service Television Association, che da almeno due anni ripete che i dispositivi "unlicensed" in questa porzione di spettro sarebbero una jattura.
i risultati dello studio della FCC sono immediatamente diventati controversi. A quanto si legge il regolatore si dice soddisfatto dei primi test sulla capacità di rilevare le frequenze occupate, ma i critici ribattono che le percentuali di errore sono ancora elevate e che le interferenze potranno essere molto dannose. La WIA propone di rafforzare tali capacità con l'uso di tecnologie apposite, per esempio imponendo agli apparati utilizzati oggi, come i radiomicrofoni, l'uso di veri e propri "radiofari" in grado di segnalare la loro presenza in banda. Nessuno ha mai detto che la cognitive radio sia una cosa facile, ma forse ci si può almeno provare.

White Space Devices

o The FCC'S Office of Engineering and Technology has released a report on tests of prototype white space devices. Radio World synopsis followed by FCC executive summary:
http://www.radioworld.com/pages/s.0100/t.15991.html
http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-08-2243A2.doc

o FCC Chairman Martin's recently announced plan to allow unlicensed wireless computer devices in unoccupied portions of the TV broadcast spectrum (the so-called white spaces) has drawn heavy fire from AMST's president David Donovan:
http://www.tvnewsday.com/articles/2008/10/15/daily.19/

o White spaces vote reportedly scheduled for Nov 4:
http://www.broadcastingcable.com/article/CA6605731.html?desc=topstory
http://tinyurl.com/WhiteSpacesVote (WSJ subscription required)

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White Space Supporters Propose Solution for Wireless Mic Industry

WASHINGTON D.C. – The Wireless Innovation Alliance (WIA) today announced its support for a compromise proposed by the White Space Coalition to ensure the protection of wireless microphones. The compromise, outlined today in a letter to the Federal Communications Commission (Available here), would employ both protection beacons and the capability to sense and avoid wireless microphones. The “belt-and-suspenders” concept of a combined beacon/sensing protection for wireless microphones had been previously proposed by Shure, the leading manufacturer of wireless microphones. The Coalition’s letter specifically proposes a way for the Commission to: (1) ensure extraordinary protection for legal wireless microphones, (2) address the open secret that most wireless microphone use in the TV bands is illegal, and (3) recognize that the use of wireless microphones by churches and other socially important users should be legalized.
“White space supporters are aware and sympathetic of the Commission’s difficult task of balancing the benefits of innovation with the legitimate concerns of incumbents,” Ed Thomas, Senior Policy Advisor and spokesperson for the Coalition said. “It has been our long held belief that balance is in the best interest of everyone involved and is simply a matter of adopting the right technological solution. Today’s proposal is that solution.”
“WIA, our partners, and supporters of white space technology in general have every interest in ensuring the continued operations of legitimate wireless microphone users,” Brian Peters, a spokesperson for the Wireless Innovation Alliance said. “A beaconing design would alleviate any concerns the Commission or the Microphone Industry Coalition (MIC) would have regarding the continued development of white space technology, and should be embraced as soon as possible. WIA is committed to working with any and all of the interested stakeholders to find reasonable solutions that can move this important process forward.”
Today’s submission also proposed that the Commission include, for the first time, most churches, Broadway theatres, and other organizations for which the Commission determines the use of wireless microphones is in the public interest, in the Agency’s list of permissible license holders in the TV band. Today most wireless microphones use in the TV band violates FCC rules.

About the Wireless Innovation Alliance:
The WIA includes more than 15 organizations, representing the technology industry, consumer and public interest groups, and educational and technical organizations. The Alliance also enjoys strong bipartisan support from a growing number of Congressional Members committed to actively working to create opportunity and enable innovation in the U.S. The goal of the Alliance is to work closely with policymakers to craft rules of the road that will realize the opportunity of TV White spaces, which lie vacant in as much as 75% in some areas of the country.
For more information about the Wireless Innovation Alliance, please visit us at: http://www.wirelessinnovationalliance.com.

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FCC chair eyes fallow TV airwaves for broadband

Wednesday October 15
By Joelle Tessler, AP Technology Writer

Federal Communications Commission pushes plan to use unused TV spectrum to deliver broadband

WASHINGTON (AP) -- The chairman of the Federal Communications Commission on Wednesday proposed opening up unused portions of the television airwaves known as "white spaces" to deliver wireless broadband service.
The proposal by FCC chief Kevin Martin appeals to public interest groups and many of the nation's biggest technology companies, including Google Inc. and Microsoft Corp., which hope it will bring affordable high-speed Internet connections to more Americans.
"No one should ever underestimate the potential that new technologies and innovations may bring to society," Martin said in a statement.
His plan could run into opposition from the nation's big television broadcasters, which have argued that the use of the fallow spectrum to deliver wireless Internet services could disrupt their over-the-air signals. The National Association of Broadcasters had no immediate comment.
Shure Inc., a manufacturer of wireless microphones, has also raised concerns about interference with audio systems at concerts and sporting events.
Martin issued his proposal ahead of the official release of a technical report by FCC engineers concluding that potential interference could be eliminated with the use of wireless transmitter devices that rely on spectrum-sensing and "geo-location" technologies to detect and avoid nearby broadcast signals.
Martin, one of three Republicans on the five-member FCC, circulated his proposal to his colleagues ahead of a Nov. 4 vote on the plan. He wants to allow the use of white spaces to provide broadband following the upcoming transition from analog to digital TV broadcasting in February, which will free up additional wireless spectrum. That space could be used to deliver high-speed Internet connections as well as improved communications networks to connect police officers, fire fighters and other emergency responders.
Supporters of the plan say the vacant spaces between television channels are particularly well suited to providing broadband since they can penetrate walls, carry a great deal of data and reach a wide geographic area.
"Freeing up these powerful airwaves will create a boom in innovative technologies and expand the opportunities for citizens to communicate with one another and the rest of the world," said Ben Scott, policy director for the advocacy group Free Press.
Scott Blake Harris, counsel to the White Spaces Coalition, added that harnessing white spaces will create a multibillion market for advanced wireless devices to transmit and receive signals, including laptops, personal digital assistants and set-top boxes. Members of the White Spaces Coalition include Microsoft, Google, Dell Inc., Hewlett-Packard Co. and Phillips Electronics.
Martin's white spaces proposal is one of several in which he is pushing to use wireless technology to bring affordable broadband to parts of the country that lack high-speed Internet. He also wants to require telecommunications carriers to use the Universal Service fund, which subsidizes phone service in underserved areas, to invest in broadband.
And he is backing a plan to auction off airwaves to a bidder that agrees to offer a free, national wireless Internet service. That proposal has run into opposition from several large wireless carriers, including T-Mobile, which warn that it could interfere with their own broadband services that rely on adjacent spectrum. But in a separate technical report released late last week, FCC engineers found that technical safeguards would prevent interference.