Dublin Bus, Ireland

The organisation moved to improve communications between dispatch staff and drivers when it installed a six-site TaitNet MPT 1327 trunked radio system mostly for voice calls. Tait mobile radios are installed in buses and control centres, and 100 Tait portable radios are also carried by supervisors and maintenance staff.

Subsequently Dublin Bus has moved to deploy Automatic Vehicle Location (AVL) throughout the fleet. It was able to implement an AVL system using the current MPT infrastructure with the TaitNet Data System (TNDS) by adding five extra TDMA channels to carry position polling data.

The sites have been designed to accommodate 30-second polling frequency automatic location updates which occur seamlessly via the same radio used for voice communications. The highly efficient switching of the Tait radio allows this to occur at a speed unnoticeable to the drivers. In addition the infrastructure has the facility for dynamic frame linked extension, which ensures that larger-than-expected radio traffic volumes can be accommodated without interrupting the data flow.

The Tait TM8235, mobile radio has since been used to replace the existing T2030 mobiles because of its data capabilities and ability to communicate over MAP27 with the INIT on-board COPILOT. Importantly during the staged rollout of the TM8235, drivers could still utilise the T2030 radio to maintain voice contact with supervisors and controllers.

With the TM8235 Tait also introduced rear port programming, which enables the on-board computer to accommodate software updates sent via wireless LAN. Previously, to update any software in bus applications, such as radios, Dublin Bus had to go through the expensive and time-consuming method of bringing an entire fleet into the workshop to carry out manual updates.