PMR plus a SIM

Stretching right across the capital region, the bus network is run wholly by franchised operators under contract. “We had it running with a standard set of systems”, Mr Reed explained. “iBus is a system which tracks every single vehicle in real time, polls each vehicle’s position every 30 seconds, and that is the core of how we manage the service. So when we talk about cutting a route, we identify the vehicles that are on it, we notify them – perhaps we do it via our own radio system, we notify them electronically – and then we monitor the effect of it.

“We have our own PMR system, an MPT 1327 system, but it’s got fallback to GSM – so every bus has got a SIM in it as well. The location telegrams are transmitted every 30 seconds on 2G. Each bus is also fitted with a wireless LAN. There’s 85 garages – they download and upload software and data every night. And there’s a short-wave radio on it to trigger traffic light priority. There are around 1850 junctions where we can hold green slightly longer or accelerate green if we need to do so.”

In addition, London Buses is an ‘orange light’ user of the Airwave network, as Mr Reed put it. “We use Airwave purely for blue-light liaison and if our own operational radio systems pack up and go down – that’s the only two uses that we are allowed to do.”

Co-located control

Perhaps the most far-reaching move made in preparation for the Olympics was a decision to co-locate TfL’s bus control centre with the Metropolitan Police’s traffic control centre. “Hopefully we are going to move the rest of our control centres in there as well”, Mr Reed commented. “So all of our road traffic control, bus traffic control and Met Police traffic control are on the same floor of the same place.

“All the systems are ‘air-gapped’, but everybody can see what each other can see. If we need the police, they are behind us. If we need to do something with the traffic lights, they are just the other side of us. All of those systems all operate with the specialists that do them and we just use proximity of human beings talking to each other.”

This proximity benefits police operations too, he added. “Because we were co-located with the Met police, you could think of our 8000 vehicles as another set of points of presence for those guys. So when our system was up and running they could ask our bus drivers to keep a look-out for things.”

To help in this, London Buses persuaded Airwave to lend it an additional 150 Airwave terminals for its ‘games ambassadors’ during the games period. “That increase in service really helped us in service provision”, Mr Reed said. “We made sure that we had the right people out there, and should anything be needed, we were there ready to cover it.”

Old-school PMR

Other communications preparations for the games included bringing maintenance work forward, change freezes and introducing additional resilience. But there was little that could be done about the system’s reliance on GPRS for tracking buses. “You could guess what was going to happen”, Simon Reed said. “We were going to get contention problems, we were going to get – people said – coverage problems. I don’t think coverage was ever the issue but contention definitely was.

“When the main stadium was open, that changed spectators twice a day. You can do the maths yourself: there’s 80 000 inside, 80 000 trying to get in, plus the other venues around – so, oddly enough, we tended to lose bus telegrams in the Stratford area when those things were changing around.

“We expected that; but you have to plan to make sure that you can deal with it and you know where your vehicles are. And that’s where the MPT radio comes into its own: it’s our own radio, it’s our own base stations and our own frequency. So we did manage to protect that at
all costs.”

Over an ordinary weekend, the MPT system typically handles between 40 and 45 000 calls a day – yet during the games period this radio traffic actually fell. Mr Reed believes that this was because London’s road network was running exceptionally smoothly, thanks to publicity campaigns designed to steer private cars and goods traffic away. “Spookily enough, now the games are over, everybody is back”, he said. “It’s a free-for-all.”

Olympic legacy

Asked about the legacy of the Olympics experience, Mr Reed highlighted an innovative ‘live information’ desk established for customer contact. “That sits with the joint operation control and is purely focused on customer information. That is one immediate point that has proved itself during the Games and that will get funded, going forward.”
(中国集群通信网 | 责任编辑：陈晓亮)