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Evolution of critical communication has been much slower. The original TETRA air interface standard, established in 1996, was supplemented by standards defining many other interfaces during 1996–2001, and this phase was later called Release 1. Services included were group call, individual call, direct mode operation, status messages, text messages (SDS), narrowband packet data and a group of supplementary services. The next evolutionary phase (Release 2) was established in 2005 and has been supplemented up to the present time. Its most important feature is the TETRA Enhanced Data Service (TEDS), which offers wideband data transmission with practical rates of 10–500 kbit/s, depending on the radio channel width, number of timeslots used and modulation. VIRVE could be updated with Release 2 features in 2012, but no decision on that has been made yet. Possible broadband support for VIRVE is farther off. There may be at least 5–10 years to wait, because the ETSI workgroup responsible has only just begun its discussions. Starting of the standardization process and the technology choices to be made will depend on future spectrum allocation decisions. Unless a sufficiently large frequency band can be identified – and it should also be harmonized across Europe for public service use, to assure a viable ecosystem – we can say goodbye to broadband within TETRA and any other dedicated technology. In that case, TETRA might remain important for mission-critical voice and low or medium rate data services, but for broadband data other technologies would have to be used. Spectrum decisions will be a key factor in determining the future of mission-critical communication. To add to the present 2×5 MHz band, the ETSI Technical Committee has put forward a proposal for an additional 2×3 MHz for narrowband, 2×3?MHz for wideband (TEDS) and 2×10?MHz for broadband data transmission. Altogether, this additional spectrum need amounts to 2×16?MHz. In Finland, an additional 2×5?MHz adjacent to the current band could be taken into use quite rapidly, adding capacity for narrowband and wideband transmission. No band suitable for broadband data is currently in sight – yet it is clear that a dedicated band will be needed for broadband communication by public authorities, irrespective of the technology to be chosen. For economic reasons, this band should be closer to 400?MHz than 1?GHz. Towards the future Information and command and control systems and their interoperability will be crucial for the successful future development of fire and rescue services. A recent development project on multi-authority co-operation and information systems (TOTI) has resulted in requirement specifications for information systems to be used by ERCs and also for command and control systems of field units (KEJO). This common definition project will ensure that future information systems are interoperable, forming a solid basis for successful multi-authority co-operation. These information systems will be deployed in 2015 at the latest, when the reconfiguration of ERCs has been completed. The position of VIRVE remains unchallenged, since no competing technology is in sight which could offer group calls and direct mode operation better than TETRA. Support for narrowband data transmission in TETRA is also adequate – it is suitable for conveying status, location and incident information. At the moment, a question mark hangs over the deployment of wideband TEDS – but TEDS could bring extra capacity to mission-critical IP data, status and SDS messages and would ensure the quality of speech services during periods of network congestion. Nonetheless, broadband data services based on VIRVE are far in the future and there is no guarantee that they will ever exist. This is why dedicated broadband data services for safety and security authorities will be needed in the near future. Today it is necessary to use commercial mobile networks, even though they are not intended for critical communication.
PUBLIC SAFETY COMMUNICATION IN FINLAND: A BOUQUET OF BEARERS
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