VietNamNet Bridge – The flight safety has been threatened by the frequency interference from local radio stations.

Radio stations obstruct flights

Nguyen Van Thu, Deputy Director of the Radio Frequency Agency, an arm of the Ministry of Information and Communication (MIC), said the aviation industry has been seriously affected by the frequency interference from local ratio stations since late 2011.

The problem is that the local radio stations commonly use the 87 – 108MHz frequency band with bad reaction quality, going beyond the technical standards, thus causing the interference to the 121MHz frequency used for flight operation.

The frequency agency has stressed that the problem has become serious, because this threatens flight safety.

Buon Ma Thuot City and Gia Lai province in the central region have been cited as the two most affected areas. The agency has repeatedly received the warnings that it is the radio stations broadcasting in Vietnamese language which has caused the interference.

Thu said his workers have been set to different location to trace down the interference sources, even though it is a very difficult work, because the workers have to track every station amid the hills and mountains, including the terrains with full obstacles.

Local authorities, the governing bodies of the radio stations, have been asked to join forces with the local information departments to take necessary measures to fix the problems. The radio stations have been asked to use standard-quality broadcasting equipments.

The efforts by the relevant agencies have helped ease the problem, while airlines and airports have stopped complaining about this.

However, Thu still keeps worried about the interference to the aviation activities, saying that there are some other reasons behind the interference as well.

At the Tan Son Nhat airport, the interference has been very complicated on the 133MHz band and many other frequency bands. Workers have been sent to the site to solve the problems. However, one of the phenomena has not been settled because the reasons have not been found.

Thu has also warned that it’s nearly impossible to settle the problems to the very root, saying that the inference may be more frequent. The technology world changes everyday with new technologies and new wireless equipments created every. Therefore, this happens that some problems are settled today, but other problems would arise tomorrow.

MIC calls for tighter control

In order to minimize the interference, Thu said, it’s necessary to deal with the key of the problem – the radio broadcasting equipment.

Thu suggested keeping a close watch over the itinerary of equipment, from the production, circulation and import. The quality of products must be controlled, especially the ones made by domestic companies and the equipments imported through unofficial channels (travelers bring the equipments to Vietnam when they enter the country).

“It’s necessary to force using the equipment which is in accord with the common standards instead of the current mechanism, which allows institutions to automatically use the equipment after submitting files to the watchdog agencies,” Thu said.

The officials from MIC have also said that the MobiFone’s 3G network has been interfered by the cordless phones Dect 6.0 standard, which have been brought to Vietnam across the borders by the Viet Kieu (overseas Vietnamese) in the US or Canada.

It is estimated that 700 cases of frequency interference caused by Dect 6.0 cordless phones were found and settled in the last two years. The frequency agency had to send technicians to search for the interfering units and found out that these were just small phones priced at less than one million dong.

Buu Dien