WPD


spots where radio coverage doesn’t quite meet all expectations. Cornwall, for example, is like a raised plateau surrounded by many small vil- lages down by the sea. “Somebody described it as like a billiard table”, Kevan says. You’ve got the fl at bit and then you’ve got these pockets where you’ve got nothing! “It’s obvious that we can’t get right in there,


although we have got some sites in Wales that fi re down to the North Somerset, North Dev- on coast, and vice versa. Occasionally guys are going to have to drive up the road to get cover- age, but there’s no mobile phone coverage in those villages anyway, so what’s the diff erence?” For voice communications, WPD


has standardized on vehicle radios, not handportables.“We trialled handportables and we decided that the benefi ts didn’t really add up”, Kevan explains. One of the reasons for this was safety – and he paints a verbal pic- ture of a technician working on live wires and speaking to the control room with a radio in one hand while clinging to 11 000 volts with the other. “So they’re in the vehicles”, he says. “We’ve got a few handhelds for test purposes and things, but we didn’t go wholesale there.”


Data devices Once the new network is up and running, Kevan intends to develop the data side of the system much more. “With the lack of chan- nels that are available for scanning telemetry, it seems stupid to have a network out there that has got really good coverage that we’re not us- ing”, he says. “We always intended to develop the project to take data for us, but essentially one of the most important things was being able to bring our fi eld communications back to the control room. T at, to start with, was voice; it will become data and there will be some telemetry on it as well.


“We’ve experimented already with handheld


devices. Handheld devices in the fi eld can be used over this system although the data rates are not as quick as the other systems you can have. So again, it will be an essential backup where coverage isn’t available.” To handle fi eld telemetry, the system will


have to be integrated with a Scada system which is based at present on very elderly equip- ment. “T ey have got 40-year-old technology in the substations, but the system here in the central part of it is really up-to-date. And there were issues with that. So all the guys who were developing the data aspects of the Xfi n tech- nology have all just pulled into that, trying to get those systems to be compatible. “It’s just a huge amount of work we are do-


ing up here – massive. We are changing all our primary Scada outstations out. We started in June and that will be fi nished by December. We are changing fi ve a day.”


When seconds count Summing up, Kevan Scott looks back at the benefi ts Western Power has gained through its trunked radio upgrade project. “It has defi nitely helped with getting customers’ electricity back on faster than it would have been if we hadn’t had it”, he says, with confi dence. “Every time we have a fault, we measure the time it takes for restoration. Each one is documented as to the method of communications to get it back on. “If we overrun on some of the restorations,


then we have to investigate them. It’s usually that we had no mobile phone coverage but we had PMR coverage, or we didn’t have either. But there are fewer cases, obviously, where we didn’t have either. T ere will always be cover- age places that aren’t brilliant – but, essentially, it’s good coverage for the size of the network and the number of sites that we’ve got.”


Engineers installing the Xfi n blade technology for the Western Power Distribution PMR network in Lamerton


D


espite the excitement surrounding DMR Tier III, Andy Grimmett of Simoco still


sees plenty of life in analogue technology. “There will be a take-up for DMR without


a doubt, and we’ve seen a big take-up of DMR Tier II already, replacing conventional radio schemes”, he says. “But we still see a lot of legs in Xfi n. We see that being a technology we will sell for some time, for a couple of reasons. “One, if you look at the market stats from


IMS Research, they show that the analogue market is still going to be dominant above any digital technology, even right up to 2015 and beyond. So analogue has still got its day. The second thing is that DMR Tier III – the trunked equivalent of MPT 1327 – is now only just emerging. “With Xfi n”, he continues, “we sold


single-site systems and two- and three-site systems for several years before we started to get up to networks that were big enough to serve something like a utility company. And I think we will see the same with DMR – probably to a bigger extent, because people going to DMR Tier III won’t just be taking a manufacturer’s new product – they will be taking a brand-new technology which has got some risk associated. “So I think DMR has got some great


At this WPD radio site, the switchless Xfi n equipment (above) has saved a large amount of rack space over the old Marconi equipment (left)


20


benefi ts to deliver. It’s delivering them now in the analogue, conventional space, but I think the trunked emergence will actually take a little while. I think it will be great for small systems. But these big systems, I don’t think we’re going to see those for a few years.”


LAND mobile September 2012


Analogue or digital systems?


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36