Ekahau: Public Transport Location Tracking in Madrid

In 2004 the city of Madrid and Consorcio Regional de Transportes de Madrid (CRTM) launched a project to build six urban transport hubs in various points throughout the city (Principe Pío, Conde de Casal, Plaza Elíptica, Plaza Castilla, Chamartín e Moncloa), with an expected completion date sometime between 2007 and 2008.  The objective of the program was to improve the public transportation structure and increase efficiency by linking the existing infrastructures (metro, urban and interurban buses, and urban and interurban railway lines) in unified access zones, hubs or interchange points.  Part of the project included the implementation of information systems to improve the level of service and, in particular, a solution to identify and locate the buses.  When all the interchange stations are completed and when the location tracking is extended to each bus, the project will be one of the most ambitious and innovative of its kind in the European public transport sector.

 

A normal GPS satellite location system was chosen for tracking the surface transportation outside of the interchange points but this technology did not work inside the hubs due to the fact that the majority of them are underground. However this critical gap needed to be filled.  It’s evident today, after a two year pilot project, that the tracking solution inside the hubs is critical for CRTM to manage and coordinate the buses at the interchange stops where thousands of passengers transit and where the availability of precise information can radically change the quality of service that is offered.  With this system, the interchange operators have an instrument available for programming the arrival and departure of the buses and can supply passengers with information about where to find their bus at any moment.   The tracking solution also helps in the maintenance operations.  The exact location is given to the technicians and mechanics so that they can immediately find the bus on which they have to carry out maintenance or repair.  The search for an adequate system for the traffic control within these underground areas took place while the hubs were under design and construction.

 

Consorcio de Transportes conducted a thorough technology study, eliminating along the way the technologies that proved not to be ideal, like GSM cellular technology, ultra wide band (UWB), and analogue radio systems.  Finally Wi-Fi technology was chosen for the tracking system.  Among the positive features of this solution was the capability to simultaneously support data collection and transmission to the control centres, plus the possibility to utilize the same platform for voice, video and data services.  The installation was conducted by Neomedia, experts in the design and implementation of telecommunication infrastructures.  “The key elements of this project, altogether, made up a frightening scenario for us as installers.  Thousands of rapidly moving objects, radio disturbances, and thousands of people, all in an underground environment,” commented Jorge Sánchez, project manager from Neomedia. “In this situation, the Ekahau RTLS system proved to be the only one able to give positive results.”  He adds, “The project started in 2005, with a first pilot phase carried out at the Avenida de America interchange.  During the next year, the system was then implemented.”  The pilot test results were very encouraging.  The tracking precision of the buses was 95,422% on a total of 105,050 passengers.   And this was the result despite the environmental difficulties encountered in the internal area of the interchange, “a very complex environment from the radio point of view, in which there are devices present with high electromagnetic emissions like fans and air treatment systems.”

 

In 2007, Wi-Fi technology was installed at the interchange station at Príncipe Pío and Plaza Castilla and during the course of 2008 the solution will be extended to the stations at Chamartín e Moncloa.

“When the project is complete, it will support two thousand buses,” explains Jorge Sánchez.  “This is a two phase project.  The first phase deals with the creation and implementation of a Wi-Fi structure to locate the buses and this is a complex process that requires very detailed radio engineering.  In an environment as complex as this one, from an electromagnetic point of view, designing the Wi-Fi infrastructure for tracking the buses requires the creation of  digital coverage for each interchange point.  This is accomplished by analyzing the placement and density of the access points, creating a radio propagation model for the antennas and tuning the transmission power of the devices.  Luckily the second phase is easier and that is the installation of the tracking devices on board the buses. As soon as the first two phases are finished, the data collection begins with the precise location coordinates and the positioning of the buses.  This data is then sent to the SGI (Sistema de Gestión Integral) at the interchange station.”

 

Neomedia’s DLA, Device Location Active

 

Neomedia also developed the DLA, the Device Location Active solution. The platform is in the process of being patented and increases the performance of RTLS systems, particularly in environments like the interchange points, where the characteristics and variables excluded the use a standard off-the-shelf product right from the start.  “During the research, test and selection phase of the various RTLS products and options on the market, the positioning engine of the Ekahau RTLS 4.0 attained the highest grade in satisfying the selection criteria” continues Sánchez.  “This 100% software engine is the result of 10 years of research at one of the most prestigious R&D groups in the world, Complex Systems Computation Group at the University of Helsinki.  It incorporates ten patents regarding location algorithms.”  The DLA solution from Neomedia doubles the performance of this solution.  “The locating range in a static positioning situation, for example at a railway platform, goes from two meters to one meter with the DLA solution” explains Sánchez.  “The T201 tag is able to read positioning data every 5 seconds, while the DLA is able to get this information at variable rate, establishing the optimal scanning rate, which could be, for example, just one second.”

 

 

This project became a personal challenge for Ekahau sales director, Jarmo Ikonen, opening doors world-wide.  “Tracking rapidly moving objects is the next frontier for our technology.  Thanks to Neomedia and the CRTM application, we have achieved this.  I believe that the success of this project will open the way to similar projects in other countries.”  “The city of Madrid, yet another time, has introduced the most advanced public transport infrastructure,” declared Manuel Lamela, Counsellor of Transport and Infrastructure for the City of Madrid.  “And this refers not just to the construction but also the management of the infrastructure, allowing more efficient operation of the new sites.  Urban and interurban passengers that use the hubs on a daily basis will be assured of high quality service in terms of speed, ease and comfort.  But not only this, all inhabitants of the city will benefit from the improvement in the quality of life, even those who don’t use public transport at the moment.  This technology, used in the underground hubs, lets us manage the lines better, so that any bus that can find a place underground, is off the surface, and this benefits the overall traffic flow in the city.  I definitely believe that the people in Madrid are proud of the application of leading edge systems in the city infrastructure, which improves service thanks to the step forward that this technology grants us.”