BT's controversial Tetra-based Airwave service is to be adopted by the Ministry of Defence (MoD) despite questions over the system's safety and security.

Tetra, which is a private wireless network, has been the subject of intense media interest because of its dubious reliability.

The expensive network has already been adopted by the police, and the announcement from the MoD that it has become a de facto standard is good news for mm02 as it took over the Airwave service following its demerger from BT last November.

Tetra uses authentication and encryption to protect traffic from unauthorised access and can be enhanced for users needing more sophisticated encryption.

The Israeli Army is using Tetra-based systems to communicate between vehicles in warzones using a highly sophisticated system.

The UK government has set a 2005 deadline for migrating the emergency services from analogue to digital radio systems.

But reports in vnunet.com's sister publication Network News suggest that tests within the police force show a dissatisfaction with Tetra.

There have been reports of signals being lost, and fears still remain that the system could be jammed by criminals.