'Out of this world' audio

It is being called the biggest breakthrough in broadcast technology since FM - and interestingly, India is already enjoying it, ahead of many countries, including the U.S. Anand Parthasarathy savours the excitement over the current state and future prospects, of satellite-based digital radio.

IN THE local showroom of BPL, a group of curious teenagers crowded around a table where what looked like four stereo systems were on display. The only difference was that each set had a flat metallic dish, the size of a small dosa, latched on to its top. But when the sets were switched on and the dishes were twisted slightly, there was an audible gasp. The music that was heard - western pop music from one set, a veena recital from another, a full blown philharmonic orchestra from the third - was stunning in quality - as good as that produced by a good stereophonic CD player.

Yet there were no CD's or audio cassettes any where in the works: This was good old radio - but of an unbelievably crystal clear quality. The reason? It was digital-all-the-way -and it was coming directly to the set, from a satellite orbiting 35,000 kms above the earth. This was radio in the 21st century - of a kind that compared well with the best hi fi audio systems. Already, industry watchers are hailing this as the greatest advance in radio technology after Frequency Modulation ( FM).

The sets on display came from four manufacturers - Hitachi, JVC, Panasonic and Sanyo - and ranged in price from Rs 4990 for the hand held Hitachi KH-WS 1 mono version to Rs 11,990 for the top- of-the-line Panasonic RE-WS 10, which boasts a four way stereo speaker system. The ``WS'' in the model names, revealed that all four models were made to the specification of WorldSpace, a 10 year old company based in Washington DC, with its core business in Africa - and now in Asia.

It has been an early leader in the race, since 1990, to create a global network of direct satellite radio stations, offering a rich mix of ``edutainment'' and music of a quality hitherto unattainable by FM or AM broadcast systems.

Interestingly, WorldSpace decided to launch its technology first in the developing world. It planned a network of three geostationary satellites, each with three beams capable of carrying 40 plus broadcast channels, and each covering a footprint of 14 million square kilometers on earth. The broadcasts are currently uplinked from Australia using a satellite dish antenna on a frequency of 7025 - 7075 MHz., at data rates selectable from 16 to 128 kilo bits per second.

The former compares roughly with monophonic Amplitude Modulation broadcasts while the latter is comparable to CD-quality stereo. Equipment on the satellite decodes these signals and beams it the customers' individual receivers on earth in the L Band ( 1467- 1492 MHz). A proprietary chip called Starmano, in each of the four brand receivers, unscrambles the signal which is compressed in the standard MPEG 2.5, Layer 3 code. When its first satellite Afristar was lofted in October 1999, WorldSpace commenced operations in Africa and the Middle East including a small portion of the Mediterranean. When the second satellite, AsiaStar was launched, a year ago this month, its swathe enabled WorldSpace to offer its service across the pan-Asian region. The third, AmeriStar is due for launch this year.In India, WorldSpace debuted its service six months ago, though its dealer network was largely confined to Bangalore. Earlier this year, the network has been extended to other neighbouring states. The company has cannily tied up with international broadcasters like BBC and CNN so that their radio services are available to customers. But the difference in quality in speech programmes may not be palpable: the real attraction of satellite digital radio is in the quality and range of music it provides - round-the-clock access to separate channels which broadcast nothing but rock, pop, jazz, classical western and Indian, indipop and regional language Indian music. Indian broadcasters who have been tied up to uplink via Worldspace include VRG (Tamil); Radio India, and Radio Khanak (both Hindi), and the Asianet Group's RM Radio ( Kannada and Malayalam). The Mumbai-based Radio Midday, a popular FM broadcaster belonging to the media group of the same name, offers a channel of its special brand of ``Hinglish'' fare.

The four receiver models available here have common features like alphanumeric display of channel name and music type, a scanner that allows you to search for the type of music you like since they are all coded) and outlets for external speakers or head phones. They can also be used for the normal AM/FM terrestrial broadcasts. Since satellite broadcasts use line of site transmissions, it may require some adjustment of the antenna to achieve good reception.

A 5-meter extension cable is provided so that you can stick the antenna dish out of your window if required. Optionally one can buy a Yagi type antenna with 25 meters of cable and put it on the roof top. These receivers are not designed to be used in moving platforms - but users in Africa have reported good reception in cars when driving through open spaces.

In the US, the Federal Communications Commission (FCC) had allocated bandwidths for digital satellite broadcasting a decade ago in the S Band ( 12.5 MHz). But the clout of the huge network of lucrative private FM station franchises, ensured that all attempts to exploit this technology were thwarted - till a year ago. That was when two competing agencies - Sirius Satellite Radio based in New York City and XM Radio of Washington, made the investment necessary to launch the satellites required for an American satellite radio service.

The focal market there was slightly different from that of WorldSpace - the 200 million car drivers on the road, hitherto stuck with CD players or local FM music-and-news radio stations which faded in and out every few kilometres. So in addition to the satellite net, the American providers had to invest in terrestrial repeaters to ensure a continuous signal in moving vehicles. Sirius launched its third and last satellite in November last and has just commenced test transmissions, having persuaded the leading car manufacturers to modify their systems to facilitate installation of satellite dishes, and audio manufacturers like Kenwood and Sony to put the matching satellite radios on shop shelves.

XM Radio is still to launch its third satellite. Customers on the North American continent may have to wait till mid 2001 to get a satellite radio service. And in addition to paying a typical $ 300 for the receivers, they can also expect to be charged a monthly subscription of about $ 10 for receiving the satellite broadcasts - something that is free in India. What next on the digital radio front? It is interesting that the WorldSpace receivers, include a 128 KBPS data port. If and when there are content providers, ready to beam not just audio but multimedia content, these same receivers can be used to download - and cache on a PC hard disk - a rich mix of sound, picture and video, at speeds that will better than the best telephone-based Internet connections.

Today's digital satellite radios may then become the front end of tomorrow's satellite-based multimedia-rich Internet feeds. They would still be one way-affairs ( unlike Internet, as we know it now, the system will not allow the user to upload files), but think of what a long way the science of radio has come! It will be exactly 100 years this year - on December 11 - since Guglielmo Marconi made his first historic wireless transmission across the Atlantic.

He struggled to hear a brief morse coded signal over the static. For broadcast speech and music the world had to wait another 17 years. Today, as we listen to the rich tones of mellifluous music flowing out of a small device that grabs it off a satellite, we are privileged to experience something like the shiver of pleasure, that pioneers like him may have felt when they first thrilled to the wonders of wireless.

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