London buses now cover more route miles and carry more passengers than ever before. More than 8000 buses now serve more than 700 routes throughout Greater London, and usage has exceeded six million passenger journeys every weekday.
London Bus Services Ltd is a division of Transport for London, and operates one of the largest bus networks in the world.
The London Bus network is one of the largest and most comprehensive urban transport systems in the world. Over six million journeys are made on London buses every day within an area of approximately 659 sq miles.
The existing radio network supporting the buses required a complete turnkey replacement following obsolescence of the core infrastructure and expansion of bus and passenger services. London Bus needed a seamless transition from this legacy radio network to the new TaitNet MPT 1327 trunked radio solution.
The overall TFL project was to introduce a state-of-the-art Automatic Vehicle Location (AVL) system along with comprehensive telecommunications. The broader goal of this and several related projects is to offer passengers Real Time Passenger Information (RTPI) at bus stops, on-board voice and signs buses and from SMS text messaging.
For London Bus it was a major priority to make sure that customers would receive a more reliable and consistent bus service.
London Bus opted for a complete replacement of its six–site network with a 10 site (VHF), 76 channel TaitNet trunked MPT 1327 network capable of supporting high quality voice and data applications. A trunked system was considered optimal for such a large number of vehicles and such a widespread area of coverage.
The radio system replacement represented a major part of an upgrade being supplied by Siemens VDO. This involved work at many locations including 90 garages and 208 dispatch workstations operated by London Buses throughout the whole of the greater London region.
The TaitNet MPT solution was customised to integrate with Siemens VICOS-LIO despatch equipment. This integrated dispatch solution delivers optimal voice communications between dispatchers and bus drivers. Voice communications can be in the form of broadcasts to all vehicles, messages to groups of vehicles or calls to individual drivers.
Other facilities such as emergency (code red) calls are also supported by the Tait system. The code red emergency call was specifically customised for maximum speed and to deliver a location of the vehicle simultaneously.
The system is complemented by Tait's reliable TM8252 and TM8255 mobile radios and robust portable radios.
The TM8252 radios are customised to meet the specific requirements of London Bus to integrate with the Siemens IBISplus on-board computer to be installed in each bus as part of the larger upgrade project. IBISplus provides the user interface for the driver, and also tracks vehicle location by combining information from a GPS unit, mapping, an odometer, Gyroscope and the opening and closing of the bus passenger doors.Prior to this project, Tait had supplied 1500 trunked mobile radios to London Bus, which allowed direct replacement of the obsolete original bus radio terminals. This allowed London Bus to maintain its legacy system while a new system was specified, designed and built. Tait was able to quickly configure a custom solution, based on its current mobile radio series, which allowed London Bus to avoid major investment in infrastructure and operator training during the period before embarking on the comprehensive upgrade provided by Siemens VDO.
Throughout the project Tait has provided a range of services including integration, coverage predictions and verification to deliver a turnkey, system-level solution. A major reason for Tait's success in this project is the ability to provide ongoing maintenance and 24/7 first line support beyond the installation of the network.
Other case studies
In this paper, we will look at reliability specifications, coverage prediction theory, and how physical, location signal measurements can verify it in a robust, repeatable and affordable way.