Data system smoothes the journey

Dublin Bus, Irish public transport operator, has chosen Tait to carry out an upgrade of its existing communications infrastructure.

The company identified the need to improve both its provision of information to the travelling public and its ability to track its vehicles and monitor their performance against a timetable.

To achieve this, the company selected a regular update of data (AVL)/real-time passenger information (RTPI) system from INIT, a German-based supplier.

Real-time systems necessitate the frequent transmission of AVL and timetable data between buses, control rooms and information displays at bus stops. For this task, the company chose the TaitNet Data System (TNDS) transmission solution.

The system enhances the company’s current multi-site voice radio system by adding digital data channels, enabling it to monitor and provide timetable compliance, improve bus headway by traffic light pre-emption, deliver real-time passenger information and provide accurate information for inter-modal services.

Existing radio systems are often unable to cope with the data speeds and volumes. This results either in buses having multiple radio systems onboard or inconsistent and incomplete data being supplied.

To deal with this, Tait developed the TDNS, based on TaitNet MPT1327 systems and TM8200 trunked terminals.

The system is scalable to the operator’s requirements and offers the capability of polling up to 900 vehicles per minute, the reliable transmission of data between vehicles, at stop signs, control rooms and traffic lights, and voice communication on the same radio.

The TNDS uses a single in-bus radio unit to provide: all the services of the trunking radio system, a regular update of data (AVL) with no bus computer required and short data bursts to pre-empt traffic lights or clear passenger signs.

The system can also control traffic light priorities. Traffic light changes could be on demand, or automatic, for example the bus computer knows the route and where traffic lights are and, if behind schedule, then changes lights to green. Also, bus stop signage can provide real time of arrival times.

“Dublin Bus selected Tait technology for the key communications aspect of the passenger information system, which will help it to further enhance the service that it offers its customers,” Paul Gwynn, business development manager at Tait Europe, said.

“TNDS offered a technologically advanced, scalable and flexible solution with low operating costs. It is also compatible with existing RTPI solutions, which will enable it to work seamlessly with Init’s bus hardware and control software.”

Tait specifically developed its TNDS system for public transport applications. It provides benefits unavailable from other offerings on the market, including:

• Voice and data are fully integrated within the same system;
• Faster polling rates than other systems;
• Sends data over a system designed to carry data;
• Includes direct traffic light control signalling; •Offers direct mode sign clear-down communications, if required.

The technology gives operators the ability to generate, capture and use KPIs for fleet operational performance, and address issues such as route selection, traffic flow and driver behaviour.

This makes for better decision making and control of the operation. All this is possible through the system as it can provide voice, data and emergency functionality all on the same technology platform.

The additional benefit is that the TNDS functionality can be added to an existing Tait trunked radio system, rather than replacing it. This made the TNDS an attractive solution for Dublin Bus.

The company has operated a Tait six-site trunked radio system since 2002. This has provided voice communications across Dublin for the company’s 1200 buses and 3000 drivers.

Tait Electronics