Mobile-phone jamming device wins award

A device that jams mobile phone signals, developed by two researchers at the National Electronic and Computer Technology Centre (Nectec), has won the Inventors' Day award in industrial science and technology from The National Research Council of Thailand.

The device, called "T-box 3.0", was developed by Komain Pibulyarojana and Siwaruk Siwamogsatham. They began more than three years ago in an attempt to cut down on the number of bombs being exploded in the southernmost provinces of Thailand. Many of the bombs used mobile phones as trigger devices.

With its potential to save lives, the project also received an honourable mention in the IT Princess Awards 2007.

Although the T-box has a simple concept of interfering with cellular phone signals, its development was far from easy and the team spent almost a year working on it.

Komain and Siwaruk - who is head of the National Security Technology and Innovation Laboratory - did everything themselves, starting with designing every circuit used in the device to searching for suitable materials and assembling the T-box.

Komain said the T-box contained integrated circuits that generated a signal jamming any incoming cellular signals, preventing anyone from making mobile-phone calls within a 100-metre radius.

The team worked with the Defence Science and Technology Office to outline the requirements for the T-box as well as testing it when complete. The first T-box was used to tackle the South's insurgency problems in late 2005 and about 50 T-boxes have since been built for the Defence Ministry.

The boxes are designed to jam four cellular frequencies: 800, 900, 1,800 and 1,900 megahertz.

Since the box was intended for a critical national security application, it had to be tested in conjunction with the Defence Ministry to ensure that it conformed to military standards.

Earlier, the ministry imported cellular jamming equipment from abroad at a cost of between Bt1 million and Bt2 million per unit. The T-boxes cost only Bt100,000 each, achieving considerable savings.

The T-boxes also cover an area with a radius of about 100m - about 10 to 20 metres wider than the imported devices. The boxes are also designed for better durability and shock resistance.

According to a military report, the boxes are used for bomb recovery missions - especially in the deep South - at least once a week.