ATA's Scoop Reporter brings 7 kHz from a single analog telephone jack to Europe 1.

AETA's Scoop Reporter brings 7 kHz from a single analog
telephone jack to Europe 1.

By Patrick Fortier
Chief Engineer
Europe 1

Europe 1 , one of France's major Radio network, has been a pioneering user of 7 kHz Digital Audio Codecs for live sport reports as early as a commercial ISDN service has been available in France in 1987. In 1992, the strong demand for higher quality (15 kHz) lead Europe 1 to move towards the HiFiSCOOP-2 , an Audio Codecs providing 15 kHz on a single "B" channel over ISDN for the same cost than 7 kHz. These equipments allow convenient quality transmission where ISDN is available. The journalists and the technicians are now very familiar with this type of compact and very simple to use Codecs.

The main problem with ISDN Codecs is that when a special event occurs, the telephone companies are not able to set up ISDN access on location within a short notice. As analog telephone lines are in most of the cases available in the area, Europe 1 along with other major Radios have been asking ATA to build a 7 kHz Audio Codec allowing transmission on the plain old telephone network. In response to this demand, ATA developped the Scoop Reporter.

Thanks to the new technology available such as V34 modems it was in theory possible to transmit up to 28.8 kbit/s on analog networks. In fact, it appears that 24 kbit/s is the highest bit rate consistently achievable on existing analog networks. This bit rate has been selected after intensive testing on real analog networks.

A low bit rate , low delay CELP algorithm has been developed by the CNET (France Telecom's world renown research laboratories) in order to provide quality equivalent to ITU G.722 for speech at bit rate as low as 24 kbit/s. This algorithm achieves 10:1 compression ratio and has been optimized for such very low bit rate and short delay. The latest digital technology has been used for implementing this complex algorithm requiring 120 millions mathematical operations per second !.

In order to keep some operational margin, fall back operation at 21.6 kbit/s with a small bandwidth reduction (6.3 kHz), is also possible. This feature allows to keep near broadcast quality even when using noisy lines.

Other requirements from Europe 1 and the other broadcasters relative to the Audio section and the ergonomy for the ATA Scoop Reporter were taken into account, and are described below:

The equipment is designed for field operation.
Rugged metal case, compact size and Audio interface allowing to a journalist and a guest to be simultaneously connected.
Two microphone inputs are available, as well as two headsets outputs, one auxiliary input and auxiliary output allows to connect a tape recorder for instance.
There are mixing capability, input selection and gain control.
The equipment can be operated from main AC or from battery.
Call is set up from a built in keypad, incoming calls are automatically answered.
There is a built in V34 modem allowing real time full duplex audio transmission.
Regular telephone quality fall back when digital connection is not possible.

The product was officially announced at the AES 95 in Paris. Europe 1 acquired immediately some equipments and put them on the field early April 1995.

After having used the Scoop Reporter on the field for six months, Europe 1 had impressive results:

The quality is perfectly convenient for live reporting. The relatively low delay allows for real interactive full duplex interviews.
Europe 1 had positive response from Scoop Reporter users as the quality is impressive and as the equipment is as simple as a plain telephone to use.
There is a real connectivity within analog telephone networks of developed countries.
During the field test, the equipment has been used nationwide with success.
The main restrictions are when telecommunication operators perform "data compression" on their lines in order to multiply the number of voice communications (ADPCM for instance). In this case as the 3 kHz telephone channels are not clear and as the V34 modulation requires the full channel capacity, some high speed data services are squeezed down to lower bit rate. This is not the case in Europe on public telephone networks even for international calls but may occur on some transcontinental calls or on private networks.
The field test has been very positive providing both good service and satisfaction of the user.
The flexibility of use on analog PSTN makes possible broadcast quality reports on the field , without notice.

Patrick Fortier
Europe 1, Telecommunications Department