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Trilithic EAS Decoder - EASy to Use

The Federal Communications Commission (FCC) mandates that all licensed, fully operational cable and wireless cable, and radio broadcast stations install an Emergency Alert Service (EAS) transmitter. In the event of a national emergency, the EAS interrupts a televised or radio program by transmitting its message on screen or on air.

Designed to serve cable television systems handling less than 5,000 subscribers, Low Power TV Broadcasters, Full Power Radio Broadcasters and the Low Power (LP) FM radio stations, Trilithic's EASy-Decoder series provides EAS monitoring that meets full FCC regulatory demands.

Trilithic's EAS Division Sales Manager, Dominick Maio, explains that the EASy-Decoder series is able to retain a rolling log of the last 1,000 EAS activations. Programmable FIPS codes (similar to zip codes) enable EASy-Decoder users to receive more specific local alerts, in addition to the national emergency signals. Should a catastrophe occur (child abduction, terrorism threat, weather disaster, etc.), the EAS system overrides the radio waves and cable systems, accelerating the process of getting the information to the public. For the nearly six million vision/hearing impaired United States residents, this practice has become an essential safety advantage.

"Trilithic is poised to stay on top of emerging technology in its field," adds Maio, stressing that the decoder series is was designed and manufactured "digital-ready" for its system applications and is all that is needed for the LP marketplace. "It's a series that was developed and scaled down from our original EASy-PLUS encoder/decoder and just for this (purpose)," validates Maio. EAS specifications state that the Trilithic EASy-Decoder can be programmed and will maintain up to as many as 64 event codes and up to 64 FIPS codes.

In addition to its valuable memory and control features, the EASy-Decoder, which measures only 3 ½ inches high, possesses a multiplicity of other assets. The PC platform is Windows-based, totally software-driven; and properly equipped, downloads and upgrades can be accessed from Trilithic's web-site. "Fifteen years from now, all you will have to do is upgrade your system from the web-site," Maio adds. Hardware changes are not necessary due to the decoder's Flash BIOS and Digital Signal Processing technology feature. Two built-in programmable AM, FM and NOAA (National Weather Service) receivers are included. Four additional receivers are an option.

The Trilithic EASy-Decoder for the LP-FM marketplace, complete with balanced stereo audio switch, retails for $1795.00, a comparatively priced amount, considering that there is no need for additional equipment, says Maio.

For more information, log onto Trilithic Inc.'s web-site at www.TrilithicEAS.com or contact Dominick Maio at 888-344-6838.

RDS: The Radio System

Questions and Answers

By Jim Wood (Inovonics Inc.)

What is the Radio Data System?

The Radio Data System is a 'hidden' communications channel within the FM radio transmission structure that provides the listener with certain added reception features, and gives the broadcaster a path for sending text and other data and for exercising some control over the listener's radio. RDS provides certain 'housekeeping' functions to help the listener find and maintain the programming he prefers, as well as affording a complete information channel of modest speed, or 'throughput'.

Digital RDS data is transmitted as a robust, inaudible 'subcarrier' at a level that does not compromise main channel audio performance or in any way interfere with other analog (SCA) or special-function digital (paging or instrumentation) FM subcarrier services.

What is the history of the Radio Data System?

RDS was developed in Europe in the early 1980s, with service beginning there between 1984 and 1987. By the mid-1990s, nearly every FM station in Europe had implemented RDS. Today there is hardly a station in Europe that does not broadcast RDS. Even low-power "local radio" services have this feature.

RDS was evaluated for use in the US about this same time. The National Radio Systems Committee (NRSC) drafted a US standard as early as 1992, naming the service "Radio Broadcast Data System," or RBDS, to distinguish it from the European standard.

By 1998 both the European and US RadioData standards had been revised to minimize the difference between the two. In all common and practical applications, RBDS and RDS can be considered the same thing.

If RDS is so widespread in Europe, why has it taken so long to catch on here?

For two primary reasons. First, there is a big difference between broadcast practices between Europe and the US. In contrast with the US, Europe utilizes a large number of lower-power transmitters to cover a given service area, which can even include the entire country. These smaller transmitters are 'networked' and carry the identical programming.

In fact, with its long history of government-controlled broadcasting, Europe still offers many networked services. A good example is the British Broadcasting Company (BBC) with its BBC-1, -2, -3, and -4 programs. One function of the RDS receiver is to keep track of networked stations and automatically—and seamlessly—re-tune to the strongest signal that carries the identical program.

The US has relatively few radio networks. Gone are the NBC, CBS and Mutual networks where one could depend on hearing Jack Benny or Amos 'n' Andy at a fixed time anywhere in the country. Even National Public Radio (NPR) stations download satellite feeds and establish their own programming schedules.

US broadcasting rules do allow broadcast 'translators,' however, which are combination receiver-transmitters. These enable a station to extend the range of its coverage and 'fill holes' in its primary coverage area. A large number of translators can even build a network. Educational Media Foundation (EMF), with its 'K-LOVE' and AIR-ONE Christian Music services use satellite program delivery to feed scores of low-power transmitters to blanket a large part of the country.

The second reason that RDS has been adopted so slowly in the US has to do with a difference in broadcast philosophy between Europe and the US. This is reflected even in the terminology used. The nature of commercial broadcasting in the US defines a broadcaster's 'market,' analogous to the 'service area' in Europe. European broadcasters view RDS as an additional service to their listeners, or "what can RDS do for my listener." Commercial broadcasters over here seek additional revenue from RDS, or "what can RDS do for me?" What are the basic RDS functions?

PS – Program Service Name… this is an 8-character ID that is sent out by the broadcaster that automatically pops up on the faceplate of every RDS radio. The PS identifier can be as simple as call letters and frequency: KZLA 939, the station's 'street name': HOT 104, or perhaps an identification of the format: TALK-FM.

The PS identifier was intended to be static. In fact, both the European CENELEC and our own NRSC standards specifically discourage 'scrolling' messages in the PS field. Nevertheless, there are no current laws that forbid this, so many stations regularly send song artist and title information, weather and stock reports, and even advertising messages. These messages must either be broken down into sequential 8-character blocks, or sent as scrolling messages like soldiers marching past a reviewing stand.

PTY – Program Type… this defines the station's format from a list. The PTY list is the big difference between Europe and the US. Since the format is identified only by a 2-digit code, it is the receiver that really determines the difference between European and domestic PTYs.

With the better RDS radios, a listener can enter the type of programming he wants to hear. If it's Country Music, for instance, the radio begins to hunt for Country stations and gives the listener a few seconds' preview of each one in range. By hitting a button, the listener can stop on the station of his choice. As he drives out of range of that station, the radio will continue to hunt for Country music and again allow the listener to choose between available Country Music options.

AF – Alternative Frequencies… the RDS radio downloads an AF list from the station it's tuned to. This list has the frequencies of any translators or other sources of the identical programming. As the listener drives around, the radio continually monitors all AF frequencies and switches over from a fading signal to a better one with little or no interruption.

RT – RadioText… not to be confused with 'scrolling PS,' this is an independent 64-character string of text that is generally transmitted as a static message. The RadioText message does not automatically appear on the faceplate of the radio. In fact, many car radios ignore RadioText, and the ones that do display it require the listener to press an INFO button to bring it up. RadioText is most useful for sending out the station's Web address, telephone numbers or upcoming program notes.

TP/TA and EAS… this feature prioritizes traffic or emergency announcements and can 'take over' the listener's radio, even switching from another station or from a CD or tape to alert the listener to important information. The TA 'flag' is a temporary data bit that controls the RDS radio. Abuse of this feature is widespread in Europe, where a listener might hear, "A big wreck has just been reported on the M25 motorway! Next up, a quarter-hour of your favorites, beginning with Norah Jones." For this reason the TA feature can be defeated on most RDS radios, although when used properly it can be a great service to drivers.

How do I implement RDS?

All it takes is an RDS encoder, which connects between the stereo generator and the broadcast exciter. The encoder samples the multiplex signal and synchronizes with the 19kHz stereo pilot to lock the 57kHz RDS subcarrier. The encoder has either a USB or an RS-232 data connection to allow programming of the RDS with any PC, or to tie directly to station automation equipment for automatic song title and artist information.

What's the cost for RDS?

An encoder with the basic RDS functions and 'static' messaging (fixed IDs and RadioText) costs around $400. For 'dynamic' messaging (scrolling PS for song titles, etc.), encoders start about $1200.

To find out more about RDS visit the Inovonics website at http:/www.inovon.com or call 1 800 733-0552.


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