Police forces across the country are turning their backs on the controversial £2.9bn Tetra mobile communications system, because it cannot process data at acceptable rates.

The Association of Chief Police Officers (ACPO) is now demanding that forces have a choice over how they transmit data.

"We want bearer independence," said Paul Friday, head of information systems at West Yorkshire Police.

The Home Office wants to reduce the admin burden on police officers and get more of them back on the beat.

Officers can be made more productive by running Police National Computer (PNC) checks quickly themselves while on patrol. A PNC check will flag up stolen vehicles, or alert officers that they are dealing with a potentially dangerous suspect.

The Terrestrial Trunk Radio system, better known as Tetra, was chosen by the government to deliver a secure radio facility to the emergency services.

But while the O2-run Airwave Tetra system is meant eventually to carry significant volumes of data traffic as well as voice calls, it can currently only offer data transfer rates of just 3Kbps.

Friday helped ACPO draw up its policy towards mobile data transmission, and insisted that forces be allowed to develop services with whichever carrier suits them best.

Some forces are already making their moves. Staffordshire Police will complete its trial using PDAs to give 60 officers access to the PNC and file crime reports while on patrol.

Staffordshire is using Orange's GPRS network rather than Airwave because it could not wait for the system to develop, according to Ian De Soyza, project manager at the force.

"The Airwave project is going to concentrate on national projects at first. Only Staffordshire and Durham Constabulary use our crime reporting system. Airwave won't support this for quite a few years," he said.

Compared to Airwave's current data speed of 3Kbps, Staffordshire Police gets connection speeds of between 20Kbps and 26Kbps with its GPRS service.

West Yorkshire Police is also piloting a mobile scheme, accessing the PNC over the Transcomm Airtime network. Meanwhile North Wales Police has been using Vodafone's GPRS network to transmit data services such as email.

O2 Airwave admitted that police forces will make a choice over how to transmit data, and acknowledged that access to PNC checks was a "vital" part of its contract with government.

"We will be testing access to the PNC over the next few months and are confident that we can meet the requirements of the emergency services," said an O2 Airwave spokeswoman.