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irwave is the world leader in ‘wide area retunes’ of TETRA public safety networks. With the addition of new sites, and changes in topography particularly in London, wide area retunes are needed periodically to ensure the Network is fully optimised to deliver the best possible quality of service, and utilises the available spectrum in the most effcient way. Airwave’s experience in retuning its Network led to an approach from Meldkamer Diensten Centrum, (MDC), from The Netherlands, to provide consultancy for the frst wide area retune of the country’s nationwide C2000 TETRA public safety network. A large number of new sites were being introduced along with an increase in capacity. This meant a redistribution of current spectrum to allow the integration of the sites and capacity requirements.

Owned by the Government, the management of the C2000 network is delegated to the National Police. The tactical and operational management, maintenance and improvement of the network within the National Police are the responsibilities of MDC, the Control Room Services Centre. Over several months, a small team of skilled Airwave individuals from the Wide Area Retune project team worked with MDC to ensure a successful retune of their network. The project was planned in phases. For the frequency planning and preparation phase, a delegation from MDC visited Hemel Hempstead to witness a wide area retune of the Airwave Network, the fourth to date. The Airwave project team then visited The Netherlands to work alongside the MDC team to

assess their network, and review the availability of spectrum.

MDC has challenges that Airwave has not yet faced, such as the frequency coordination with land bordered countries (Germany and Belgium). Further constraints had to be applied to the frequency plan, due to restrictions on equipment and the factoring in of new sites as new data became available.

During the pre-retune phase, a series of workshops was held with the MDC technical team, with Airwave supporting the end to end processes, from reviewing the initial data collection through to the frequency plan implementation and verifcation on the night of the retune. Events, such as the abdication of Queen Beatrix of The Netherlands, affected the timescales as capacity had to be added to, and then removed from, the network to deal with the increased network traffc.

The abdication also clashed with the date of the retune, and delayed it by a week.

For the actual retune, Airwave was on hand to help if necessary. Jason Barnett, Airwave’s Confguration and Network Manager, paid tribute to the MDC team: “Their company structure is different to ours, and they had to consolidate many cross-functional roles into a small technical team. They followed the plans and processes, and carried out the retune with a success rate of 99% on the night with the remaining issues being mopped up within 24hrs. MDC is now the second company in the world, after Airwave, to have undertaken a wide area retune of a TETRA network on this large scale.

“This was a valuable exercise with lessons learned on both sides, and we have built up a good relationship which will stand us in good stead for the future.”