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Trunking


backed up by a generator and battery backup, and suchlike”, Mr Hunt continues. “At Crys- tal Palace, for example [south London], we are wired into the Crystal Palace main generators, which I believe can run for three months. And it’s the same at Emley Moor. “At all of our platinum sites, also, we


have fully-redundant aerial arrays. I think we’ve only got two sites which we haven’t got two aerials at. Te equipment, by its design, is inherently extremely reli- able. If one base station fails, it doesn’t affect customer quality of service.”


Data applications Traffic loadings on the net- work are being monitored weekly so that system capacity can be increased if necessary – or, conversely, reduced if it is


not being used. Besides voice communica- tion, Fleetcomm’s network will also be able to offer data servic-


Above: radio coverage of the reborn Fleetcomm MPT 1327 network. Zones tinted in pink are currently being added to complete the network’s national backbone. Further coverage in England will be added next year. The company also hopes to serve the Edinburgh– Glasgow–Aberdeen transport axes later


ment that any digital system is mature enough to put on such a demanding client base. “We’ve also played a lot with digital com-


panding on the mobile radios – digital signal processing – and that seems to offer as many improvements in audio or speech quality. It gets rid of all the noise, which is what digital does, and then you have all the advantages of ana- logue. Tait radios support it, Kenwood mobiles support it; most analogue radios now support companding using digital signal processing. And that seems to offer just as many advantages to the audio quality as digital does.”


Performance Speech quality is also benefiting from the new inter-site links, thanks to some in-house engi- neering effort. Mr Hunt says: “I developed an IP linking technology whereby the sites actually communicate with each other now and the au- dio doesn’t come near Goole. Which I believe is unique. Te Goole end will be involved with the call setup; but then, once it’s going, none of the audio will come anywhere near Goole – which gives you much better audio.” For a reliable network, extensive protection


against failure is necessary at the radio sites. “We don’t classify a site as platinum unless it’s


30 es, including data-only applications.


Mr Hunt says he has been in discussions with one potential customer who has a requirement to broadcast data at a very low bit rate, nation- wide. Up to now, this stream has been broadcast on the RDS carrier of Classic FM radio – but the RDS service is expensive to use and very limited in capacity. “So just by using our control chan- nel and sending out a packet every five seconds, which will put very low loading on the network, our network then becomes the data carrier for them”, Mr Hunt explains. “We are looking at applications such as that and we are attracting quite a lot of interest.” Another potential use is for emergency re-


sponder type applications, as a fall-back option for Airwave service users. “We’re aiming to make our network fully in- dependent from the BT network”, he explains. “Several people are looking at it as an alternative to the Airwave network, because it’s a completely independent wide-area cover- age network.”


Return to trunking With the improvements which have been made across its system, Fleetcomm hopes to win back some of the customers who have drifted from trunked radio across to cheap mobile phones. One factor which may lure them over is the very fast call set-up for voice communication in an MPT system – a significant benefit, espe- cially in any kind of emergency. “We’ve got this debate with one of our cus-


tomers at the moment”, Mr Hunt says. “Tey went over to mobile phones, but they said the call set-up time was too slow. Tey’ve come


back to us because of the call set-up time. An inter-site call sets up in about 1½ seconds – so you could call from Manchester to your base in London and it should take about 1½ seconds for the call to set up. If you’re local, the call sets up in about a quarter of a second.” And he adds: “Suppose you are a lorry driver


carrying high value stuff in the back of your lorry. If you suddenly get attacked, you can just pick up the microphone and say, ‘Help, I’m be- ing attacked!’. It takes three seconds. Try to get your PDA to do any of that: by the time you’ve pressed the emergency button on one of these PDA devices, you still haven’t told information. “It’s a much quicker backwards-and-for-


wards method then mobile phones. Tere’s no call charges, so you can use it as much as you want, which is another advantage. We’ve got group call across a very wide area with a single site – and the single sites are very cheap now. We are aiming to try and cut our single site costs as much as we possibly can. And we’ve got the tracking.” In addition, he points that the mobile phone


networks are beginning to become congested by heavy data usage – and he believes that their coverage is becoming intermittent in some ar- eas as operators withdraw sites to cut costs. So now, with service options to suit a wide


range of business users, and coverage fast ex- panding, Fleetcomm is ready to demonstrate the full potential of trunked radio as a subscrip- tion service once again. “I’m a great believer in MPT 1327”, com-


ments John Kelly, managing director of the company. “Tere’s a whole realm of things that we are endeavouring to do – but the first thing is to get back to some kind of even quasi-na- tional infrastructure.”


Remember these names? Nationwide two-way radio services for business have been absent from the UK for some years, but now an operator is busy reviving the concept – and working to build the case for their performance and value for money


LAND mobile October 2011


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