Satellite radio
From Wikipedia, the free encyclopedia
A satellite radio or subscription radio (SR) is a digital radio signal that is broadcast by a communications satellite, which covers a much wider geographical range than terrestrial radio signals.
Satellite radio is currently at the forefront of the evolution of radio services in some countries, notably the United States. Mobile services, such as Sirius, XM, and Worldspace allow a listener to roam across an entire continent, listening to the same audio programming anywhere he goes. Other services, such as Music Choice or Muzak's satellite-delivered content require a fixed-location receiver and a dish antenna. In all cases, the antenna must have a clear view to the satellites. In areas where tall buildings, bridges, or even parking garages obscure the signal, repeaters can be placed to make the signal available to listeners.
Radio services are usually provided by commercial ventures, and are subscription-based. The various services are proprietary signals, requiring specialized hardware for decoding and playback. Providers usually carry a variety of news, weather, sports, and music channels, with the music channels generally being commercial-free.
In areas with a relatively high population density, it is easier and less expensive to reach the bulk of the population with terrestrial broadcasts. In the UK and some other countries, the contemporary evolution of radio services is focused on Digital Audio Broadcasting (DAB) services, such as HD Radio.
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[edit] Satellite Radio Providers
[edit] United States
In North America, there are two satellite radio companies, XM Satellite Radio and Sirius Satellite Radio. These two former rivals have announced their intention to merge, which would create a single satellite radio entity in the United States with nearly 14 million subscribers.
[edit] Canada
XM Canada and Sirius Canada, operated as separate entities from their American counterparts with 51% ownership by different Canadian companies, may eventually merge as well. However, Sirius Canada's market share is quadruple that of XM, and their standpoint is that a 50/50 ownership split in a new company would be inequitable. XM Canada, however, owns a lucrative contract with the NHL, which it feels would bring a great deal to the merged company in hockey-crazed Canada.
[edit] Europe, Asia, and Africa
WorldSpace is the sole mobile satellite radio provider in Asia and Africa, and seeks to expand into Europe. The European Space Agency, however, has unveiled a plan and a prototype to use pre-existing satellites to construct a satellite radio service. The satellites were part of Europe's original satellite TV system, and are nearing the end of their operational lives. As satellite radio doesn't require the exact satellite positioning that a dish-based TV system does, their lives can be extended even though the satellites are drifting out of their original orbits.
[edit] Other areas
Areas outside of the Worldspace, XM, or Sirius footprint, including Australia, New Zealand, and the Hawaiian Islands, do not yet have access to mobile satellite radio services. There are several satellite TV services which operate in these areas and can provide audio programming via dish antennas.
[edit] Business applications
Satellite radio, particularly in the United States, has become a major provider of background music to businesses such as hotels, retail chains, and restaurants. Compared to old-line competitors such as Muzak, satellite radio's significantly lower price, commercial-free channel variety, and more reliable technology make it a very attractive option. Both North American satellite radio providers offer business subscriptions, though given the merger of XM Satellite Radio with Sirius, the future of XM for Business is uncertain. Sirius' commercial services are provided nationally by third-party partner Applied Media Technologies Corporation.
[edit] System design
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 Broadcasting (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. For example, Sirius uses channel 184 "Sirius Weather & Emergency".
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.
Like other radio services, satellite radio also transmits program-associated data (PAD or metadata), with the artist and title of each song or program, and possibly the name of the channel.
[edit] Satellite radio vs. other formats
Satellite radio differs from AM or FM radio, and digital television radio (or DTR) in the following ways. The table applies primarily to the United States.
| 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 television set-top box (the primary function of the set top-box is normally designed for cable or satellite television viewing) |
| 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 high |
| Sound quality | Varies2 | AM: Very low FM: High |
Varies2 |
| Variety and depth of programming | Highest | Variable — highly dependent upon economic/demographic factors | Variable - dependent on the satellite television provider and the various packages they provide and on the user's subscription |
| Frequency of programming interruptions (by DJs or commercial advertising)3 | none to high - mostly dependent on the channels which some have DJs, most channels are advertisements free because of the paid subscription model of satellite radio | Highest4 | none to low - dependent on the provider, however it's common that some stations will have DJs. usually no advertisements (DirecTV and Dish Network both claim to provide advertisement free content) |
| Governmental regulation | Yes5 | Yes — significant governmental regulations regarding content6 | Low to none 5 |
2 The sound quality with both satellite radio providers and DTR providers varies with each channel. Some channels have near CD-quality audio, and others use low-bandwith audio suitable only for speech. Since only a certain amount of bandwidth is available within the licenses available, adding more channels means that the quality on some channels must be reduced. Both the frequency response and the dynamic range of satellite channels can be superior to FM, and even the worst channels are still superior to AM broadcasts.
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.
4 Nonprofit stations and public radio networks such as CBC/Radio-Canada, NPR, and PRI-affiliated stations and the BBC are commercial-free. In the US, all stations are required to have periodic station identifications and public service announcements.
5 In the United States, the FCC regulates technical broadcast spectrum only. Program content is unregulated. However, the FCC has tried in the past to expand its reach to regulate content to satellite radio and cable television, and its options are still open to attempt such in the future. The FCC does issue licenses to both satellite radio providers (XM and Sirius) and controls who holds these licenses to broadcast.
6 Degree of content regulation varies by country, however the majority of industrialized nations have regulations regarding obscene and/or objectionable content.
[edit] United States
In the United States, two companies operate satellite radio services: 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. Both stations have commercial-free music stations and talk and news stations that include commercials. 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, tunnels, 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.
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. In addition, many people do not want to pay for something that they're used to getting for free; this alone may be the chief obstacle in gaining widespread adoption of satellite radio service. On the other hand, satellite radio's chief asset is the fact that it is not localized: drivers can receive the same programming anywhere in the footprint of the service. A stop at any truck stop will demonstrate the popularity of XM among long-haul drivers. In addition, both XM and Sirius carry programming that is simply not feasible on commercial radio stations. Specialty stations cover things such as family talk, radio drama, classical music, and live events.
The footprint of both Sirius and XM is only the United States (including Alaska), Canada, and the upper third of Mexico; it does not cover Hawaii as satellite TV does.
[edit] Success so far
As of January, 2007, XM has claimed "7.6 million" subscribers, while Sirius claimed "6 million". One critical factor for the success of satellite radio is the deployment of in-car receivers. Both Sirius and XM have attempted to convince automakers to equip vehicles with their receiver. As of 2007, the following manufacturers offer satellite radio as original equipment:
| Provider | BMW MINI Rolls-Royce |
Chrysler Dodge Mercedes-Benz Jeep |
Ford Lincoln Mercury Volvo Land Rover Jaguar Mazda |
GM Cadillac Chevrolet Buick Pontiac GMC Opel Vauxhall Saturn Saab |
Honda Acura |
Hyundai Kia |
Mitsubishi | Nissan Infiniti |
Porsche | Toyota Lexus Scion |
VW Audi Bentley |
Suzuki |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sirius | Yes | Yes | Yes | No | No | Yes | Yes | Yes | No | Yes | Yes | No |
| XM | No | No | No | Yes | Yes | Yes | No | Yes | Yes | Yes | No | Yes |
Sirius has an exclusive contract for VW and Audi vehicles from 2007 through 2012. Those brands previously offered both services. GM, Honda and Suzuki are all major investors in XM, so not surprisingly, Sirius is not offered as options in their vehicles. [1] Bentley and Rolls-Royce come not only with Sirius receivers, but lifetime subscriptions. XM is also featured in select Harley-Davidson motorcycle models, while Sirius can be heard in several brands of recreational vehicles and boats.
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, Sirius S50, Here2Anywhere and the Sirius Stiletto 100. [2] While key agreements with automobile 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.
[edit] Canada
On November 1, 2004, the Canadian Radio-television and Telecommunications Commission (CRTC) began hearing applications for Canada's first satellite radio operations. Three applications were 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.
On June 16, 2005, the CRTC approved all three services.
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 a one time activation fee of $19.99 (100 channels). (All prices are in Canadian dollars)
Read the CRTC's public notice concerning Canadian satellite radio services
[edit] Asia, Africa and most of Europe
WorldSpace has its own satellites covering most of Europe, Asia and Africa. The signal can be received by specialised WorldSpace receivers. Many of the programs are available only to subscribers.
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.
South Korea started S-DMB service in May 1, 2005.
[edit] Standards
[edit] ETSI
ETSI released the following ETSI Satellite Digital Radio (SDR) specifications:
- TS 102 550 Satellite Earth Stations and Systems (SES);Satellite Digital Radio (SDR) Systems;Outer Physical Layer of the Radio Interface
- TS 102 551-1 Satellite Earth Stations and Systems (SES);Satellite Digital Radio (SDR) Systems;Inner Physical Layer of the Radio Interface;Part 1: Single carrier transmission
- TS 102 551-2 Satellite Earth Stations and Systems (SES);Satellite Digital Radio (SDR) Systems;Inner Physical Layer of the Radio Interface;Part 2: Multiple carrier transmission
ETSI Specifications are open standards available at ETSI Publications Download Area (this will open ETSI document search engine; free registration is required to download PDF).
WorldSpace will use ETSI SDR in its new network covering Europe from 2008.
[edit] DVB
DVB-SH is suitable for radio too.
[edit] See also
[edit] External links
- XM Satellite Radio XM Satellite Radio Company
- Sirius Satellite Radio Sirius Satellite Radio Company
- XM Satellite Radio, Canada XM Canada
- Sirius Satellite Radio, Canada Sirius Canada
- WorldSpace Satellite Radio WorldSpace Satellite Radio Company
- Compete: Sirius.com vs XMradio.com Traffic Graph
- Alt.radio.satellite Satellite Radio Newsgroup
