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Transit routes

Date: 08th October 2012
Topic: Monthly Features
Issue: Issue 10
Manufacturer: Sepura
Tags: TCCA

CB180708_018.jpgAs the world’s population rises and more and more people make their way to cities, the opportunity for TETRA to be used in urban mass transit applications is also increasing – all adding up to major opportunities for vendors and system builders. According to the International Association of Public Transport (, by 2025 around 60 per cent of the world’s population will live in cities. This in turn will lead to an expected increase of around 50 per cent in passenger journeys compared with 2005.

The benefits of an efficient mass transit system are both economic and environmental. In ‘dense’ cities, the cost of transport to the community accounts for around five per cent of gross domestic product (GDP) – but this rises to over 12 per cent in sprawling cities where the car is the only effective means of transport. For example, it is estimated that Singapore, Hong Kong and Munich spend around six per cent of their GDP on mobility – while in Houston that figures rises to 14 per cent. 

Similarly, when we look at the carbon footprint of those journeys, far greater efficiencies are realizable through the use of more advanced light mass transit systems – especially when initiatives involving increased electrification and the use of biofuels are involved. On top of this, many cities are also introducing congestion charges and increasing their fees for parking in city centres.

Technology of choice

Robin Davis, chair of the TCCA Transport Group sums up the current situation – and the opportunities for the TETRA community: “There’s been a steady and continuous increase in the number of TETRA installations on trams, buses and light rail systems over the last few years and it’s become recognized as the de facto technology for these types of operations. In fact, though large-scale public safety projects drove TETRA’s early applications development, recent figures show that transport applications have now overtaken that market.

He continues: “Transport operators have been deploying TETRA since its inception and the reasons are very clear. Operators are typically looking for high-quality, reliable, resilient and secure transmission coverage over the entire area of their operations. They’re looking for technology that can accommodate both voice and data channels as well as the facility to have private, group and individual calls. This, combined with PTT and emergency call operation – plus the ability to readily interoperate with emergency services – has made it the technology of choice. In some situations, existing networks deployed for metro use are now being expanded to cover other transport systems such as buses and trams, leveraging the original investment.”

While metro systems are already well established around the world, light rail systems are becoming increasingly attractive because they can often be installed on top of existing rights of way without the kinds of delay, disruption or expense involved in acquiring rights of way, excavation and construction.

Currently, Europe is leading the way in use of light rail systems, with around 170 already in use and another 100 more under construction or being planned. Though the USA is second with 30 systems in operation and 10 under construction, the Asia-Pacific market represents the fastest growing sector, while some Middle Eastern countries are also well advanced. 

Voice plus data

Voice communications have always been the basics of TETRA, but the system’s ability to support data applications will be increasingly exploited as communities try to make the shift towards ‘smart city’ models. The complexity of the modern urban environment – and especially its increasing vulnerability to disruption from both natural and man-made disasters – requires newer, more integrated ways of running utilities and societies in intelligent and dynamic ways.

Steve Barber, head of product strategy at Sepura, believes that while voice communications are going to remain important, transmitting data is now a key issue for transport operators. “There are multiple drivers for investment in urban transport communications systems beyond the standard macro issues to do with operating costs, environmental concerns and expanding capacity. For example, there’s a growing expectation from an increasingly connected public that detailed data will be available to help them plan their journeys. There’s also a complementary requirement from regulators to measure both performance and conformance with operating licences.” 

He adds: “While the delivery of location information has been a common requirement, traffic light pre-emption, vehicle telemetry including engine temperatures, fuel usage and so on are the other common uses for data.”

In terms of the market potential, it’s also significant that there’s considerable strategic work underway around the world to integrate and streamline previously separate urban transport operations under one central authority. In addition, there’s also a growing consolidation amongst commercial transport operators around the world. Both forces spell good news for the TETRA community in the coming years.

Nantes: pioneering TETRA in public transport

The city of Nantes, which sits at the gateway between Brittany and the west coast of France, has long been a pioneer in the area of public transport. As early as 1985, when trams were seen by many as an outmoded form of transport, the city became the first in country to re-introduce trams and now has the third largest tram network in France – with 42 km of routes spread across three lines. At the time, the wholesale removal of tramlines from cities across Europe after the Second World War was still a recent memory and so this was a brave step.

The city, in the form of its transport authority SEMITAN (Société d’Économie Mixte des Transports en commun de l’Agglomération Nantaise), has also gone against the trend in other parts of Europe by increasing the degree of separation between its radio system and its passenger information and vehicle location system. It has, however, also shown itself to be leading the way in adopting a city-wide TETRA network, on which a wide variety of public services will operate their voice and data communications.

As in many cities, public transport usage has risen over recent years, driven by both an environmental and intelligent transport systems agenda and, more recently, by the economic downturn and the rising cost of fuel. With an estimated 120 million passengers having used the SEMITAN network in 2010, the operator was keen to:

  • maximize usage of the existing bus and tram network;

  • further improve the integration of the bus and tram networks;

  • improve customer service, through improved security, traffic flow and visibility of its timetables.

Radio rollout

SEMITAN operated two separate passenger information/vehicle location systems for the bus and tram networks respectively, as well as a legacy analogue radio system which was inextricably linked to both systems. To ensure that all systems operated optimally, SEMITAN chose to initially install a radio system and then to implement a passenger information/vehicle location system later. The radio system’s objective was to ensure passenger safety and security, primarily through voice calls between drivers, on-street controllers and the control centre.

After a competitive tender, Sysoco was chosen to supply the radio system. This was initially designed to cater for the requirements of SEMITAN’s bus network, however the tram network was then added to the system shortly after completion, and a significant number of other municipal services are now also joining the system. Local police, refuse collection, street cleaning, parks services, road maintenance and parking are all services which could, eventually, use the TETRA network. The 12-site system was intended to cover the entire city and its suburbs, but is also designed to expand into the broader Nantes area. 

More than 400 vehicles are equipped with Sepura SRG3900 mobile radios, whilst the SEMITAN on-street controllers and maintenance staff have a fleet of 90 Sepura STP8000 handportable radios at their disposal. All the terminals are GPS-enabled.

Enhancing service

The radio system’s main uses are to ensure customer safety and to improve customer service. The TETRA network offers secure communications and excellent coverage across the Nantes area.

Sepura’s GPS feature enables accurate vehicle location, which is particularly relevant for the management of incidents and accidents. These are the major causes of interruption and disruption to customers’ journeys and so the use of the radio network to provide effective management of these situations is crucial.

The next stage for SEMITAN will be the implementation of a passenger information system which, whilst procured separately, will need to be closely integrated into the radio system. Currently, SEMITAN uses Sysoco’s multi-operator GEREBUS control and dispatch system with AVL services, but an eventual move to a fully-featured passenger information system is planned.

Integrated TETRA system helps keep Paris moving

'Aimer la ville’ – Love the City – says the slogan of the Régie Autonome des Transports Parisiens’ (RATP). And from the Seine to the Sorbonne, from the Notre Dame to the Musée d’Orsay, from the Tuileries to the Île de la Cité, RATP helps people in and around Paris to truly discover and love the city.

More than three billion passenger journeys are made each year on the Paris metro, tram, bus and regional express trains through Paris and the Île-de-France, making the RATP network the densest and largest metropolitan transportation system in the world.

To keep Parisians and visitors flowing seamlessly, the RATP must keep its communications flowing seamlessly as well. It relies upon a fully integrated TETRA network from Cassidian to connect a total of 15 000 users across 1000 trains, 4500 buses and 300 stations. In addition, RATP now offers access to its TETRA network for use by other organizations.

Among RATP’s radio users is its security force, which employs the TETRA network for group calls, status and SDS messages and emergency calls. It also uses Dynamic Group Number Assignment (DGNA), which enables RATP to create unique user groups on-demand for special events or incidents.

One challenge in setting up RAPT’s network was to provide adequate underground coverage. In particular, the engineers had to share cables between different radio networks, manage planning and power budgets and enable successful handovers in the tunnels.

Sharing the benefits

Since 2004, when the first of the network’s 450 base stations was installed, RATP has developed its own expertise in designing, implementing and operating its fixed and radio communication systems. Now RATP is spreading the word about TETRA by offering its services to other organizations, such as the City of Paris, the municipal police forces of individual cities around Paris, plus a local transport company. Over the next few years, some 2000 to 5000 more users could be added to the network’s capacity.

Despite the diversity of organizations and users involved, security has never been a problem. Organizations can use the secure TETRA radio system without being overheard by anyone outside the network. In addition, the system’s full Virtual Private Network (VPN) functionality enables RATP and the other organizations to share the network without compromising each other’s privacy or security.

Opening up the TETRA radio network will improve RATP’s return on investment. The extra commercial revenues will help ensure long-term sustainability of what is now a strategic regional network.


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