Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Digital Radio shopping experience:

1. Compare - without doubt the biggest advantage that the Digital Radio offers shoppers today is the ability to compare thousands of Digital Radio at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.

2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about

3. Testimonials - don't know anybody that has bought a Digital Radio? Wrong! If the Digital Radio is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.

4. Questions - Got a question about Digital Radio then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....

5. Reputation - Never heard of the company selling Digital Radio? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Digital Radio and build up a picture of their reputation for sales, returns, customer service, delivery etc.

6. Returns - still worried that even after all of the above your Digital Radio wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.

7. Feedback - happy with your Digital Radio then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.

8. Security - check for the yellow padlock on the Digital Radio site before you buy, and the s after http:/ /i.e. https:// = a secure site

9. Contact - got a question about Digital Radio, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.

10. Payment - ready to pay for your Digital Radio, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.

Digital radio describes radio technologies which carry information as a digital signal. The topic covers both broadcasting by radio and two-way communications. The acronym Digital audio broadcasting has been used to identify the generic technology of digital audio broadcasting, although now it has become synonymous with the EUREKA 147 standard.

One-way digital radio One-way digital radio standards One-way standards are those used for broadcasting, as opposed to those used for two-way communication. While digital broadcasting offers many potential benefits, its introduction has been hindered by a lack of global agreement on standards. The Digital audio broadcasting (DAB) for digital radio is the most commonly used and is coordinated by the World DMB Forum, which represents more than 30 countries. This standard of digital radio technology was defined in the late 1980s, and is now being introduced in many countries. Commercial DAB receivers began to be sold in 1999 and, by 2006, 500 million people were in the coverage area of DAB broadcasts, although by this time sales had only taken off in the UK and Denmark. In 2006 there are approximately 1,000 DAB stations in operation. http://www.worlddab.org/benefits.php There have been criticisms of the Eureka 147 standard and so a new 'Digital audio broadcasting#DAB+' standard has been proposed.

To date the following standards have been defined for one-way digital radio:

See also software radio for a discussion of radios which use digital signal processing.

Status by country DAB adopters Digital Audio Broadcasting (DAB), also known as Eureka 147, has been under development since the early eighties, has been adopted by around 20 countries worldwide. It is based around the MPEG-1 Audio Layer II audio codec and this has been co-ordinated by the World DAB Forum. DAB receivers are selling well in some markets.

WorldDMB announced in a press release in November 2006http://www.worlddab.org/upload/uploaddocs/WorldDMBPress%20Release_November.pdf, that DAB would be adopting the HE-AAC audio codechttp://www.worlddab.org/upload/uploaddocs/WorldDMBPress%20Release_November.pdf, which is also known as eAAC+. Also being adopted are the MPEG Surround format, and stronger error correction coding called Reed-Solomon coding.http://www.worlddab.org/upload/uploaddocs/WorldDMBPress%20Release_November.pdf. The update has been named DAB+. Receivers that support the new DAB standard will be released during 2007.

DAB and DAB+ cannot be used for mobile TV because they do not include any video codecs. DAB related standards Digital Multimedia Broadcasting (DMB) and DAB-IP are suitable for mobile radio and TV both because they have MPEG 4 AVC and WMV9 respectively as video codecs. However a DMB video sub-channel can easily be added to any DAB transmission - as DMB was designed from the outset to be carried on a DAB subchannel. DMB broadcasts in Korea carry conventional MPEG 1 Layer II DAB audio services alongside their DMB video services.

USA The United States has opted for a proprietary system called HD Radio or IBOC. The three US IBOC schemes are being promoted by iBiquity Digital. All three schemes are based on "Orthogonal Frequency Division Multiplexing (OFDM)" modulation, which is also used for European terrestrial digital TV broadcast (DVB-T). All three companies have now entered into a joint venture to form iBiquity.

The FM digital schemes in the U.S. provide audio at rates from 96 to 128 kilobits per second (kbit/s), with auxiliary "subcarrier" transmissions at up to 64 kbit/s. The AM digital schemes have data rates of about 48 kbit/s, with auxiliary services provided at a much lower data rate. Both the FM and AM schemes use lossy compression techniques to make the best use of the limited bandwidth.

The National Radio Systems Committee (NRSC) and the three IBOC companies began tests in December 1999. Results of these tests remain unclear, which in general describes the status of the terrestrial digital radio broadcasting effort in North America. Some terrestrial analog broadcast stations are apprehensive about the impact of satellite radio on their business, while others plan to convert to digital broadcasting as soon as it is economically and technically feasible.

While traditional terrestrial radio broadcasters are trying to "go digital", most major US automobile manufacturers are promoting digital satellite radio. Satellite radio is distinguished by its freedom from censorship, its relative lack of advertising, and its ability to allow people on the road to listen to the same stations at any location in the country. While these are clear advantages, listeners must currently pay an annual or monthly subscription fee in order to access the service, and must install a separate security card in each radio or receiver they use.

Ford Motor Company and DaimlerChrysler are working with Sirius Satellite Radio, previously CD Radio, of New York City, and General Motors Corporation and Honda are working with XM Satellite Radio of Washington, D.C. to build and promote satellite DAB radio systems for North America, each offering "CD quality" audio and about a hundred channels.

Sirius Satellite Radio launched a satellite constellation of three Sirius satellites during the course of 2000. The satellites were built by Space Systems/Loral and were launched by Russian Proton (rocket) boosters. As with XM Satellite Radio, Sirius implemented a series of terrestrial ground repeaters where satellite signal would otherwise be blocked by large structures including natural structures and high-rise buildings.

XM Satellite Radio has a constellation of three satellites, two of which were launched in the spring of 2001, with one following later in 2005. The satellites are Boeing (previously Hughes) 702 comsats, and were put into orbit by Sea Launch boosters. Back-up ground transmitters (repeaters) will be built in cities where satellite signals could be blocked by big buildings.

The Federal Communications Commission has auctioned bandwidth allocations for satellite broadcast in the S band range, around 2.3 GHz.

The perceived wisdom of the radio industry is that the medium has two great strengths: it is free and it is local. Satellite radio is neither of these things; however, in recent years, it has grown to make a name for itself by providing uncensored content (most notably, the crossover of Howard Stern from terrestrial radio to satellite radio) and commercial-free, all-digital music channels that offer similar genres to local broadcast favorites.

Japan Japan has started terrestrial sound broadcasting using Integrated Services Digital Broadcasting#ISDB-Tsb and Integrated Services Digital Broadcasting#2.6 GHz Satellite Sound digital broadcasting

Korea On 1 December 2005 South Korea launched its T-DMB service which includes both television and radio stations. T-DMB is a derivative of DAB with specifications published by ETSI. More than 110,000 receivers had been sold in one month only in 2005.

Developing nations Digital radio is now being provided to the developing world. A satellite communications company named WorldSpace is setting up a network of three satellites, including "AfriStar", "AsiaStar", and "AmeriStar", to provide digital audio information services to Africa, Asia, and Latin America. AfriStar and AsiaStar are in orbit. AmeriStar cannot be launched from the United States as Worldspace transmits on the L-band and would interfere with USA military as mentioned above.

Each satellite provides three transmission beams that can support 50 channels each, carrying news, music, entertainment, and education, and including a computer multimedia service. Local, regional, and international broadcasters are working with WorldStar to provide services.

A consortium of broadcasters and equipment manufacturers are also working to bring the benefits of digital broadcasting to the radio spectrum currently used for terrestrial AM radio broadcasts, including international shortwave transmissions. Over seventy broadcasters are now transmitting programs using the new standard, known as Digital Radio Mondiale (DRM), and commercial DRM receivers are available. DRM's system uses the MPEG-4 based standard aacPlus to code the music and CELP or HVXC for speech programs. At present these are priced too high to be affordable by many in the third world, however.

Low-cost DAB radio receivers are now available from various Japanese manufacturers, and WorldSpace has worked with Thomson Broadcast to introduce a village communications center known as a Telekiosk to bring communications services to rural areas. The Telekiosks are self-contained and are available as fixed or mobile units.

Two-way digital radio standards

References External links



Digital radio describes radio technologies which carry information as a digital signal. The topic covers both broadcasting by radio and two-way communications. The acronym Digital audio broadcasting has been used to identify the generic technology of digital audio broadcasting, although now it has become synonymous with the EUREKA 147 standard.

One-way digital radio One-way digital radio standards One-way standards are those used for broadcasting, as opposed to those used for two-way communication. While digital broadcasting offers many potential benefits, its introduction has been hindered by a lack of global agreement on standards. The Digital audio broadcasting (DAB) for digital radio is the most commonly used and is coordinated by the World DMB Forum, which represents more than 30 countries. This standard of digital radio technology was defined in the late 1980s, and is now being introduced in many countries. Commercial DAB receivers began to be sold in 1999 and, by 2006, 500 million people were in the coverage area of DAB broadcasts, although by this time sales had only taken off in the UK and Denmark. In 2006 there are approximately 1,000 DAB stations in operation. http://www.worlddab.org/benefits.php There have been criticisms of the Eureka 147 standard and so a new 'Digital audio broadcasting#DAB+' standard has been proposed.

To date the following standards have been defined for one-way digital radio:

See also software radio for a discussion of radios which use digital signal processing.

Status by country DAB adopters Digital Audio Broadcasting (DAB), also known as Eureka 147, has been under development since the early eighties, has been adopted by around 20 countries worldwide. It is based around the MPEG-1 Audio Layer II audio codec and this has been co-ordinated by the World DAB Forum. DAB receivers are selling well in some markets.

WorldDMB announced in a press release in November 2006http://www.worlddab.org/upload/uploaddocs/WorldDMBPress%20Release_November.pdf, that DAB would be adopting the HE-AAC audio codechttp://www.worlddab.org/upload/uploaddocs/WorldDMBPress%20Release_November.pdf, which is also known as eAAC+. Also being adopted are the MPEG Surround format, and stronger error correction coding called Reed-Solomon coding.http://www.worlddab.org/upload/uploaddocs/WorldDMBPress%20Release_November.pdf. The update has been named DAB+. Receivers that support the new DAB standard will be released during 2007.

DAB and DAB+ cannot be used for mobile TV because they do not include any video codecs. DAB related standards Digital Multimedia Broadcasting (DMB) and DAB-IP are suitable for mobile radio and TV both because they have MPEG 4 AVC and WMV9 respectively as video codecs. However a DMB video sub-channel can easily be added to any DAB transmission - as DMB was designed from the outset to be carried on a DAB subchannel. DMB broadcasts in Korea carry conventional MPEG 1 Layer II DAB audio services alongside their DMB video services.

USA The United States has opted for a proprietary system called HD Radio or IBOC. The three US IBOC schemes are being promoted by iBiquity Digital. All three schemes are based on "Orthogonal Frequency Division Multiplexing (OFDM)" modulation, which is also used for European terrestrial digital TV broadcast (DVB-T). All three companies have now entered into a joint venture to form iBiquity.

The FM digital schemes in the U.S. provide audio at rates from 96 to 128 kilobits per second (kbit/s), with auxiliary "subcarrier" transmissions at up to 64 kbit/s. The AM digital schemes have data rates of about 48 kbit/s, with auxiliary services provided at a much lower data rate. Both the FM and AM schemes use lossy compression techniques to make the best use of the limited bandwidth.

The National Radio Systems Committee (NRSC) and the three IBOC companies began tests in December 1999. Results of these tests remain unclear, which in general describes the status of the terrestrial digital radio broadcasting effort in North America. Some terrestrial analog broadcast stations are apprehensive about the impact of satellite radio on their business, while others plan to convert to digital broadcasting as soon as it is economically and technically feasible.

While traditional terrestrial radio broadcasters are trying to "go digital", most major US automobile manufacturers are promoting digital satellite radio. Satellite radio is distinguished by its freedom from censorship, its relative lack of advertising, and its ability to allow people on the road to listen to the same stations at any location in the country. While these are clear advantages, listeners must currently pay an annual or monthly subscription fee in order to access the service, and must install a separate security card in each radio or receiver they use.

Ford Motor Company and DaimlerChrysler are working with Sirius Satellite Radio, previously CD Radio, of New York City, and General Motors Corporation and Honda are working with XM Satellite Radio of Washington, D.C. to build and promote satellite DAB radio systems for North America, each offering "CD quality" audio and about a hundred channels.

Sirius Satellite Radio launched a satellite constellation of three Sirius satellites during the course of 2000. The satellites were built by Space Systems/Loral and were launched by Russian Proton (rocket) boosters. As with XM Satellite Radio, Sirius implemented a series of terrestrial ground repeaters where satellite signal would otherwise be blocked by large structures including natural structures and high-rise buildings.

XM Satellite Radio has a constellation of three satellites, two of which were launched in the spring of 2001, with one following later in 2005. The satellites are Boeing (previously Hughes) 702 comsats, and were put into orbit by Sea Launch boosters. Back-up ground transmitters (repeaters) will be built in cities where satellite signals could be blocked by big buildings.

The Federal Communications Commission has auctioned bandwidth allocations for satellite broadcast in the S band range, around 2.3 GHz.

The perceived wisdom of the radio industry is that the medium has two great strengths: it is free and it is local. Satellite radio is neither of these things; however, in recent years, it has grown to make a name for itself by providing uncensored content (most notably, the crossover of Howard Stern from terrestrial radio to satellite radio) and commercial-free, all-digital music channels that offer similar genres to local broadcast favorites.

Japan Japan has started terrestrial sound broadcasting using Integrated Services Digital Broadcasting#ISDB-Tsb and Integrated Services Digital Broadcasting#2.6 GHz Satellite Sound digital broadcasting

Korea On 1 December 2005 South Korea launched its T-DMB service which includes both television and radio stations. T-DMB is a derivative of DAB with specifications published by ETSI. More than 110,000 receivers had been sold in one month only in 2005.

Developing nations Digital radio is now being provided to the developing world. A satellite communications company named WorldSpace is setting up a network of three satellites, including "AfriStar", "AsiaStar", and "AmeriStar", to provide digital audio information services to Africa, Asia, and Latin America. AfriStar and AsiaStar are in orbit. AmeriStar cannot be launched from the United States as Worldspace transmits on the L-band and would interfere with USA military as mentioned above.

Each satellite provides three transmission beams that can support 50 channels each, carrying news, music, entertainment, and education, and including a computer multimedia service. Local, regional, and international broadcasters are working with WorldStar to provide services.

A consortium of broadcasters and equipment manufacturers are also working to bring the benefits of digital broadcasting to the radio spectrum currently used for terrestrial AM radio broadcasts, including international shortwave transmissions. Over seventy broadcasters are now transmitting programs using the new standard, known as Digital Radio Mondiale (DRM), and commercial DRM receivers are available. DRM's system uses the MPEG-4 based standard aacPlus to code the music and CELP or HVXC for speech programs. At present these are priced too high to be affordable by many in the third world, however.

Low-cost DAB radio receivers are now available from various Japanese manufacturers, and WorldSpace has worked with Thomson Broadcast to introduce a village communications center known as a Telekiosk to bring communications services to rural areas. The Telekiosks are self-contained and are available as fixed or mobile units.

Two-way digital radio standards

References External links





Digital Radio Now
A free user guide and resource to the digital radio world, including station lists and finder utility, product information and where to buy.

Digital Radio Now - Stations
Digital Radio Now - A one-stop guide to DAB Digital Radio. Features include a unique, postcode based station finder, complete list of products available and retailers stocking.

Digital One
National commercial digital radio provider. Information on the 10 stations, coverage and digital radio products.

ukdigitalradio: Coverage
National commercial digital radio multiplex operator. Find out more about DAB digital radio and check how many stations you can receive.

BBC - Radio - Digital Radio
With a DAB digital radio you can get the BBC's 11 national stations, including 5 digital only stations, and 32 local stations as well as many non-BBC stations

BBC - Digital - Radio
Find out what digital radio is and how to receive it. ... The BBC is not responsible for the content of external internet sites

Get DAB Digital Radio
Digital radio provider for the West Midlands area, with eight stations. News, coverage map, information about each station and contacts.

Digital Radio Development Bureau - DRDB
Development agency for digital radio. System information, station finder, equipment and retailer details, FAQ and multimedia demo.

Digital Guide - Radio Times
Switchover, Freeview, Freesat, digital terrestrial - it's all explained in Radio Times ... Digital Guide: Welcome to the Radio Times Digital Guide, where we explain all you need to ...

Digital Radio Information - DAB/DAB+, Internet radio and radio via ...
Focuses on DAB audio quality in the UK and campaigns to improve it, with a particular emphasis on the current state of the medium.

 

Digital Radio



 
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