From Free net encyclopedia
A satellite radio or subscription radio (SR) is a digital radio that receives signals broadcast by communications satellite, which covers a much wider geographical range than terrestrial radio signals.
SR functions anyplace there is line of sight between the antenna and the satellite, given there are no major obstructions, such as tunnels or buildings. SR audiences can follow a single channel regardless of location within a given range.
Because the technology requires access to a commercial satellite for signal propagation, SR services are commercial business entities (not private parties), which offer a package of channels as part of their service—requiring a subscription from end users to access its channels. Currently, the main SR providers are WorldSpace in Europe, Asia and Africa, and XM Radio and Sirius in North America. All are proprietary and non-compatible signals, requiring proprietary hardware for decoding and playback. These and other services have news, weather, sports, and several music channels.
Satellite radio uses the 2.3 GHz S band in North America, and generally shares the 1.4 GHz L band with local Digital Audio Broadcast (DAB) stations elsewhere. It is a type of direct broadcast satellite, and is strong enough that it requires no satellite dish to receive. Curvature of the Earth limits the reach of the signal, but due to the high orbit of the satellites, two or three are usually sufficient to provide coverage for an entire continent.
Local repeaters similar to broadcast translator boosters enable signals to be available even if the view of the satellite is blocked, for example, by skyscrapers in a large town. Major tunnels can also have repeaters. This method also allows local programming to be transmitted such as traffic and weather in most major metropolitan areas, as of March 2004.
Each receiver has an electronic serial number (ESN)-Radio ID to identify it. When a unit is activated with a subscription, an authorization code is sent in the digital stream telling the receiver to allow access to the blocked channels. Most services have at least one "free to air" or "in the clear" (ITC) channel as a test, and some outside the U.S. have a few free programming channels, though this may end up being a loss leader tactic to lure more listeners until satellite radio gains more widespread use.
Most (if not all) of the systems in use now are proprietary, using different codecs for audio data compression, different modulation techniques, and/or different methods for encryption and conditional access.
Satellite radio vs. other formats
|Radio format||Satellite radio||AM/FM||Digital television radio (DTR)|
|Monthly fees||$12.95 U.S. and up||None||Very low — DTR represents a small portion of the total monthly television fee|
|Portability||Available||Prominent||None — a typical set consists of a stereo attached to a set-top box|
|Listening availability||Very high — a satellite signal's footprint covers millions of square kilometres||Low to moderate — implementation of AM/FM services requires moderate to high population densities and is thus not practical in rural and/or remote locales||Very high1|
|Sound quality||Lower than cd-quality2||Lowest — especially on the AM band||High|
|Variety and depth of programming||Highest||Variable — highly dependent upon economic/demographic factors||High|
|Frequency of programming interruptions (by DJs or commercial advertising)3||Low to high — satellite radio features a mixture of commercial and non-commercial formats; most stations have DJs||Highest4||None to low — some DTRs have DJs|
|Governmental regulation||Low5||Yes — significant governmental regulations regarding content6||Low|
1 Except in the case of DTR distributed through digital cable services, for which availability is low.
2 The sound quality with both satellite radio providers may not always be comparable to FM radio. This is because XM and Sirius must add many channels in the tight bandwidth limits the FCC has placed on both companies.
3 Some satellite radio services and DTR services act as in situ repeaters for local AM/FM stations and thus feature a high frequency of interruption.
5 In the United States, the FCC regulates technical broadcast spectrum only. Program content is unregulated.
6 Degree of content regulation varies by country, however the majority of industrialized nations have regulations regarding obscene and/or objectionable content.
In the United States, two companies dominate satellite radio: XM Satellite Radio and Sirius Satellite Radio. A monthly fee is charged for both services (as of 2005 Sirius also offers a one time fee of nearly $500 valid for the lifetime of the equipment). Originally some XM music channels had commercials, while Sirius was commercial-free. As of September 2005 XM has 67 commercial-free music channels; 39 channels of news, sports, talk, and entertainment; 21 dedicated traffic and weather channels, and 23 play-by-play sports channels,. Sirius has 65 music-only channels as well as traffic and weather reports for major cities. XM uses fixed-location geostationary satellites in two positions, and Sirius uses three geosynchronous satellites passing over North and South America, to transmit the digital streams. The net difference is that the Sirius signal comes from a higher elevation angle in the northern part of the U.S., and even more so in Canada. (This higher angle makes Sirius' signal less likely to drop out on cities, but more likely to drop out in parking garages, gas stations, and other covered spaces.)
Both services are available mainly via portable receivers in automobiles, but both have many accessories so one can listen at home through a home stereo, with a portable boombox, or online through a personal computer. Both services now have some form of receiver that is completely portable. These units have added a new dimension to the use of portable satellite radio.
Some critics of the service have expressed concerns that satellite radio will lead to a decline in the number and variety of local radio stations and programming and greater concentration of mass media in the hands of fewer companies. There are also concerns that the ability to transmit local channels on repeaters, which is currently prohibited by FCC regulation, is only a rulemaking proceeding away from being legalized and further threatening existing local broadcasters.
Success so far
One critical factor for the success of satellite radio is the deployment of in-car receivers. Both Sirius and XM have attempted to convince carmakers to equip vehicles with their receiver. As of 2005, the following manufacturers offer satellite radio as original equipment:
Sirius has an exclusive contract for VW and Audi vehicles from 2007 through 2012. Those brands previously offered both services.
One of the challenges for satellite radio has been to move away from cars and into the homes of consumers. Several portable satellite radio receivers have been made for this purpose. XM satellite radio has developed the XM2go™ line of "walkman-like" portable receivers, such as the Delphi MyFi™, the Pioneer AirWare™ and Giant International's Tao™. Sirius has developed the Kenwood Portable Satellite Radio Tuner, Here2Anywhere and the Sirius S50 (although neither is a true portable in comparison to XM's XM2go: Here2Anywhere is a plug-and-play receiver, and the S50 must download programming from a home or car docking kit and cannot receive live programming on its own). While key agreements with car manufacturers are still being made, both companies have made the leap away from satellite radio only in the car and into the homes of consumers.
On November 1, 2004, the Canadian Radio-television and Telecommunications Commission (CRTC) began hearing applications for Canada's first satellite radio operations. Three applications have been filed: one by Standard Broadcasting and the CBC in partnership with Sirius, one by Canadian Satellite Radio in partnership with XM, and one at the last minute by CHUM Limited and Astral Media.
The first two would use the same systems already set up for the U.S., while CHUM's application is for a subscription radio service delivered through existing terrestrial DAB transmitters rather than directly by satellite (although satellites would be used to deliver programming to the transmitters). The CHUM service is all-Canadian; the other two applications propose to offer a mix of Canadian-produced channels and existing channels from their American partner services.
A small "grey market" already exists for Sirius and XM receivers in Canada in which a Canadian would have an American order their receiver and setup.
In its decision, the CRTC required the following conditions from the satellite radio licensees:
- A minimum of 8 channels must be produced in Canada and for each Canadian channel 9 foreign channels can be broadcast.
- At least 85% of the content on the Canadian-produced channels (whether musical or spoken word) must be Canadian.
- At least 25% of the Canadian channels must be French-language stations.
- At least 25% of the music aired on the Canadian channels must be new Canadian music.
- At least 25% of the music played on the Canadian channels must be from up-and-coming Canadian artists.
These conditions were an extension of the existing Canadian content rules applicable to all broadcasters in Canada. The applicants had until 13 November, 2005 to notify the CRTC of their decision. Both companies managed to negotiate the standards a little to their favor, and in return they would instead play 50% French content as opposed to 25%. Also, XM Canada succeeded in getting an extra 5 channels of National Hockey League Play-by-Play onto their platform, without an additional channel creation, by agreeing to cover every Canadian team's game during the season.
CHUM appealed the decision, claiming they would not survive if Sirius and XM both were allowed in the Canadian market, and that the licence conditions regarding Canadian content imposed on Canadian Satellite Radio and Sirius Canada were too lax. Canadian Satellite Radio and Sirius Canada countered that CHUM was simply trying to create a monopoly in the Canadian market.
In late August 2005, Heritage Minister Liza Frulla asked the federal cabinet to review the CRTC decision, and possibly send it back to the CRTC for further review. Lobbyists complained that the CRTC decision did not require enough Canadian content from the broadcasters. The broadcasters responded by promising to add additional Canadian and French content.
After vigorous lobbying from both sides, the Federal Cabinet officially accepted the CRTC decision on September 10, 2005.
XM satellite radio was launched in Canada on November 29, 2005. Sirius followed later on December 1, 2005. Monthly subscription rates are $12.99 for XM (85 channels) with a one time activation fee of $19.99 and $14.99 for Sirius with no activation fee(100 channels). (All prices are in Canadian dollars)
Asia, Africa and most of Europe
A large number of radio stations are available free-to-air on geostationary satellites targeting Europe throughout the Ku band, but these require fixed dish installations and as a result, are impractical for use in vehicles. Reception is often tied to a satellite television decoder. Both analogue stations, as subcarriers in SÉCAM and PAL analogue satellite signals, and digital, as DVB-S streams and Astra Digital Radio subcarriers, are in use.
- Orbitcast.com - All Things Satellite Radio
- Digital Insurrection Satellite Radio Info
- Getting Satellite Radio One subscriber's easy how-to guide
- Digital Home Canada Canadian Satellite Radio Information and Discussion forums.