**5.2.1 Functionality**

486 Wireless Communications and Networks – Recent Advances

In this section, we describe the most important technical considerations about the BTMS. The main issues are those related to (1) trains positioning, (2) wireless 'train-to-earth' communications and (3) added value services. These three issues are described below.

1. **Train positioning system.** The BTMS permits a new way of train positioning which works independently of the main system operation. In order to achieve this target, a new hardware/software module is boarded on each train. This module combines the positioning data provided by some hardware devices (accelerometers, gyroscope, odometer, etc.) with the coordinates given by a GPS module. To generate the most accurate positioning information, this system parts from a railway lines different tabulation ways. In this case, the tabulation is related to lines lengths (in kilometres) and the traffic signals positions. Based on this information, and the data extracted from the hardware and software modules boarded on trains (including GPS), this system translates this information to kilometric points (Shang-Guan et al., 2009). Then this

Besides, the BTMS communicates with an external positioning information system which permits the reception of train positioning information generated by the main

2. **Real-time train-to-earth wireless communications.** The BTMS permits real-time train traffic management, so it is necessary to enable a real-time wireless communication channel between the BTMS installed on the control centre and the trains. For this reason, this service needs to use the previously explained train-to-earth wireless communications architecture, which enables slight communications and is based on

3. **Additional Services.** Using the mentioned train-to-earth communication architecture and the information provided by the on board positioning system positioning, two

The first one is a *Statistical Analysis Service*, which using the information stored by the positioning system on a data base, the BTMS can make statistical analysis related to the system's reliability level, GPS and GPRS coverage, and other system functionality aspects. Thus, one of the main goals of this service is to compare the received information, determining if the positioning provided by the train-side systems is according to the information generated by the primary CTC system. And the second is a *Control Message Exchanged Service*, which allows the procedural alarms transmission to the train-side systems. These kinds of alarms indicate anomalous situations to the train drivers: primary system failure, signal exceeds authorization to a certain point as a consequence of a failure

One of the main objectives of applications running inside the train is to provide information in order to facilitate the work of the train driver. Usually these applications need to use information generated in the ground centre. If this information changes, it needs to be updated remotely. In addition, there are terrestrial applications that use information generated by some on board applications. Therefore, it is necessary to be able to download

services have been developed related with the functionality of the BTMS.

positioning information is sent to the control centre in real-time.

mobile technologies (Aguado et al., 2005).

of any electro-mechanical track component, etc.

that information from trains.

**5.2 Remote Application Management Service (Remote-AMS)** 

**5.1.2 Architectural and design issues** 

CTC system.

The main functionality of this service is to control the updating of the information used by applications running on the train terminal (for example track flat information or supporting documentation for the driver generated by the ground information systems) as well as downloading and deleting information generated by some on board applications (for example log files) remotely from the ground centre.

The solution consists of two software applications, one for the "ground" (control centre) and the other to be deployed in all train terminals. These applications are integrated with the previously described connectivity architecture via heavy communication since it involves the exchange of large volumes of information that do not require real-time communications.

Therefore, in this case, the Broadband Communication Manager (BCM) will be responsible for the arbitration of the train-to-earth heavy communication requests which are made by the software application running on the ground centre. This terrestrial application aims to communicate with those applications running inside the train to carry out all tasks related to the described service.

Thus, the terrestrial Remote-AMS application is installed on ground centre, and it will be responsible for managing the status of all applications in each terminal. On the other hand, on board Remote-AMS application will handle update, download and deletion requests made by the terrestrial Remote-AMS application. So, **terrestrial and on board Remote-AMS functionality** involves these issues:

