Tetrapol and TETRA: a briefing
How did it happen and with what outcomes?
Both Tetrapol and TETRA are digital, cellular trunked radio systems. The main differences between these professional mobile radio (PMR) systems and public mobile radio systems such as GSM are faster call set-up, group calls, priority calls, encryption, and ability to make direct calls without connection via a base station.
Although TETRA was adopted by the European Telecommunications Standardisation Institute (ETSI) as the European standard, Tetrapol delivered operational systems at an earlier date, rolling out the worlds first large-scale digital PMR network in 1988 (RUBIS for the French National Gendarmarie). The first TETRA systems were installed in 1997. By comparison, Tetrapol is a mature, proven system with a successful history of use in large-scale/national networks, while TETRA implementation continues to be fraught with technical problems. (See Will it work?)
Beware of this myth: TETRA is THE (only/preferred) European standard. Since 1996, the TETRAPOL Standard was recognised by the vast majority of the European and International bodies such as the International Telecommunication Union; CEPT; European Police Co-operation Council; ETSI Board (in March 1999 ETSI accepted the Tetrapol Publicly Available Specification TETRAPOL is fully compliant with the ETSI Technical Specifications [ETS]); and The Radio Communication Agency.
Tetrapol currently has over 80 networks deployed in 34 countries with over 70% of the European digital PMR market.
Tetrapol is a continuous wave transmission that does not pulse.
Tetrapol utilises frequency division multiple access (FDMA) which divides a set of channels amongst users who are each given a portion of the available bandwidth for their permanent use. Greater range and therefore better coverage is achieved than with other channel access methods (eg, TDMA), giving better reception over wider cell coverage. The dedicated control channel provides a more robust air interface.
Tetrapol is interoperable with TETRA and with analogue systems in both network and direct mode. This has been demonstrated at recent exhibitions.
Satellite communications are operationally deployed, with Her Majestys Government interfacing with Tetrapol.
Lead times for Tetrapol depend on the size of network and scope of provision. In response to an urgent operational requirement, a complete system shelter was deployed in Kosovo in four weeks, while a network of 2,500 users was implemented in Iraq in nine months. Following an extension of the initial contract, the Sirdee network serving the police and guardia civil in Spain now provides a national network, delivered within three years, on budget and on time.
Tetrapol meets all European standards for interfacing with other equipment, including ETSI 300-113 specification for co-siting with other electrical equipment. It may therefore be deployed in sensitive areas without detriment or risk to, for example, medical equipment in ambulances and hospitals.
The increased cell range achieved means that fewer base stations are required for a Tetrapol network, in comparison with a TETRA network providing similar coverage. Planning exercises have indicated that ratios of 1:2 to 1:5 can be expected.
Tetrapol networks currently cover in excess of 1.4 million square kilometres, providing a service to 420,000 users. There are no known health problems for these users.
Tetrapol has been used successfully by the British military, with satellite links, in Iraq throughout the latest conflict. It is reported as performing very well indeed.
Footnote, May 2005: EADS, who own Tetrapol, are buying Nokias interest in TETRA. Their perspective? Perfect interoperability, always denied by O2 Airwave.
Tetrapol mast in Switzerland