SR functions anyin which where there exists line of sight between a antenna and the satellite, given no major even obstructions, like tunnels or buildings. SR audiences potty watch one channel regardless of location within the given range.

Because the technology takes access to the commercial satellite for signal propagation, SR services come commercial business a cappella (non personal parties), which offer a pack of trend lines when section of their service —requiring the subscription from end users to access its trend lines. Presently, a independent SR providers come WorldSpace (Intl.), XM Radio & Sirius (U.S.), as part of their each being proprietary and non-compatible signals, requiring proprietary hardware for decoding and playback. Two these & more services develop news, weather, sports, and many music channels.

System design
Satellite radio utilizes a Deuce.3GHz S band in North America, and usually shares a Ace.4GHz L band with local Digital Audio Broadcast (DAB) stations elsewhere. These are the nature and severity of direct broadcast satellite, and is hard sufficiency that it takes there are no satellite dish to receive. Curvature of the Earth limits the email of the signal, however due to the high orbit of the satellites, two or tercet come ordinarily sufficient to provide coverage for an entire continent.

Local repeaters similar to broadcast translator boosters enable signals to be available possibly in case a watch of the satellite is blocked, e.g., by skyscrapers in a big town. Major tunnels can also stand repeaters. This method as well allows local programming to become transmitted like traffic & atmospheric condition around major metropolitan areas, though this is not however implemented.

For each one receiver has an electronic serial number (ESN) to identify it. After the unit is activated with the subscription, an authorisation code is sent in the digital stream telling the receiver to allow access to the blocked trend lines. Virtually all services keep around at least 1 "free to air" or "in the clear" (ITC) channel as a test, and a select few outside a U.S. have the couple yours free! programming trprevent lines, though this will end higher existence a bait and switch tactic to lure additional auditor until satellite radio profits more far flung utilize.

Virtually everthing (within case does'nt all) of the systems in utilise okay, come proprietary, using different codecs for audio data compression, different modulation techniques, and/or different methods for encryption and conditional access.

Rather more radio services, satellite radio also transmits program-associated data (PAD or metadata), with a artist and title of each song or programme, and even a title of the channel.

Satellite radio vs. other formats
Satellite radio differs from either AM or FM radio, and digital television radio (or DTR) in the as a consequence ways:

^Unity Except in the example of DTR distributed across digital cable services, for which availability is online.

^Deuce Occasionally satellite radio services & DTR services work when in place repeaters for local AM/FM stations & so feature the high frequency of interruption.

^Three Public radio networks like CBC/Radio-Canada, NPR- and PRI-affiliated stations and a BBC are commercial-free.

United States
In the United States, two corporations dominate satellite radio: XM Satellite Radio and Sirius Satellite Radio. The each month fee is charged for each services (as of 2005 Sirius also offers the in one case fee of about $500 valid for the lifespan of the devices). Originally a few XM music trend lines experienced commercials, while Sirius was commercial-free streaming. When of September 2005 XM has 67 commercial-free music trend lines; 39 trend lines of news, sports, talk, & amusement; Twenty-one dedicated traffic & atmospheric condition trend lines, & Xxiii play-by-play sports trend lines,. Sirius hwhen 65 music-single trend lines likewise as traffic & weather reports for major cities. XM operate deuce geostationary satellites while Sirius utilizes tercet geosynchronous satellites. Two services come available chiefly vithe personal receivers within auto, however each keep close at hand numbers of accessories and so 1 may listen personal across a home stereo, with the personal boombox, or on the net across the personal computer. Each services currently own occasionally form of receiver that is totally personal. These units own added the recently dimension to the utilize of personal satellite radio.

A select few critics of the service have expressed concerns that satellite radio may lead to the decline in the total & kind of local radio stations and programming and greater concentration of mass media in the hands of fewer corporations. There are too concerns that the ability to transmit local trend lines in repeaters, which is presently prohibited by FCC regulation, is merely a rulemaking proceeding away from existence legalized & farther threatening existent local broadcasters.

A footprint of both Sirius & XM is single a continental U.S.; it does not cover Hawaii, nor even Alaska as satellite TV does.

Success so far
When of April 1, 2005, XM claimed 3.7 million subscribers, & Sirius claimed I.One million.

A single critical factor for the profits of satellite radio is the deployment of around-car receivers. Each Sirius & XM keep close at hand attempted to convince carmakers to equip vehicles with their receiver. As of 2005, the when a consequence manufacturers offer satellite radio as original devices:

Canada
In November 1, 2004, the Canadian Radio-television and Telecommunications Commission (CRTC) began hearing applications for Canada's first satellite radio operations. 3 applications use at times been filed: a single by Standard Broadcasting and the CBC in partnership with Sirius, 1 by Canadian Satellite Radio in partnership with XM, & a single at a eleventh hour by CHUM Limited and Astral Media.

A foremost both would apply a equivalent systems already install for the U.S., when CHUM's application is for the subscription radio service delivered across existent terrestrial DAB transmitters like than directly by satellite (although satellites would become utilized to deliver programming to the transmitters). the CHUM service is everthing-Western; a more 2 applications propose to offer a mix of American-produced trend lines & existent trend lines from either their American partner services.

The little "grey market" already exists for Sirius & XM receivers around Canadthe where a Western would use at times an American sequentially their receiver & setup.

In June 16, 2005, the CRTC approved wholly ternion services.

Inside its guide, a CRTC mandatory a below conditions from either a satellite radio licencee: The minimum of Eighter trend lines must become produced inside Canada & for every American channel Nina from carolina foreign trend lines may be broadcast. At least 85% of the content on the American-produced trend lines (whether musical theater or even spoken word) must exist as American. At least 25% of the American trend lines must exist as French-language stations. At least 25% of the music airy on the American trend lines must exist as recently Canadian music. At least 25% of the music played on the American trend lines must become from either higher-&-gumptious American creative person.

These conditions were an extension of the existent Canadian content rules applicable to all broadcasters inside Canada. A applier got until 13 November, 2005 to notify the CRTC of their guide.

CHUM appealed a guide, claiming it would nin live whenever Sirius & XM each were let in a American market, & that the licence conditions on American content imposed on American Satellite Radio & Sirius Canada were as well lax. American Satellite Radio & Sirius Canadthe countered that CHUM was only trying to produce a monopoly in the Canadian market.

Inside late August 2005, Heritage Minister Liza Frulla asked a federal cabinet to read the CRTC guide, & even send it back to the CRTC for farther view. Lobbyists complained that a CRTC guide did non take plenty American content from either a broadcasters. A broadcasters responded by promising to add extra American & French content.

Fallowing vigorous lobbying from either each sides, a Federal Cabinet officially accepted a CRTC guide in September 10, 2005. Official launch dates come but non known, however todays reports indicate satellite radio can be available inside Canada when early when December 2005, eventually for the holiday season.

[http://www.crtc.gc.ca/archive/ENG/Notices/2005/pb2005-61.htm Read the CRTC's public notice concerning Canadian satellite radio services]

Asia, Africa and most of Europe
WorldSpace has its own satellites covering virtually all of Europe, Asia and Africa. A signal may be received by specialized WorldSpace receivers. Numerous of the computer program come available merely to subscribers.