AIRWAVE is a new £2.9 billion police communications system currently being rolled out across all of the UK.

Critics, including members of the scientific and communications communities, have claimed that because the system uses different frequencies to earlier emergency communications systems it could be dangerous to health.

The system has also been accused of being vastly over-priced compared to alternative systems and the Government has had its method of tendering the contract criticised by the European court. 

Recent estimates claim that 85% of the 3,300 required transmitters have already been installed across the UK and the operators say that the remaining 15% will be in place before the end of the year.

Eventually it is planned that the system will be used by all the emergency services.

The Airwave system is being installed because the Government sold off the frequencies previously used by police radios as part of the £20billion mobile phone licence auction.

The controversy surrounding Airwave has grown because it uses a TETRA or Terrestrial Trunked Radio system to transmit and receive signals.

TETRA promises greatly improved sound quality and numerous additional facilities useful to the police such as one-to-one, one-to-group and group-to-group communications. The system’s operators also claim TETRA is unaffected by other signals such as those from taxi cab firms and pirate radios, which have previously plagued police communications systems.

Unlike other radio systems, TETRA uses something called Time Division Multiple Access (TDMA) and operates with four channels on a single radio carrier wave.

The system operates its TDMA at 17.6 hertz meaning that TETRA operates by sending out pulsed frequencies slightly over 17 times each second, ensuring its signals are classified as microwaves rather than radio waves like previous emergency communication systems.

A frequency of 17.6hz is considered very low and even Government-appointed experts have warned it may prove dangerous.   

Various scientists have claimed such a frequency interferes with normal human brain activity in people either using the receivers or living or working near the transmitting base stations.

It is also thought that frequencies above 16hz can interfere with the human immune system and may lead to an increased likelihood of some forms of cancer.