The Syndicat Mixte des Transports pour le Rhône et l'Agglomération Lyonnaise, short SYTRAL, is the public transport system in the Lyon greater metropolitan area of France. It organizes the local public transport and operates the public transport under the names TCL and OPTIBUS. To ensure the
reliability of the urban transit system in the future, SYTRAL required a digital data radio network that transmits, above all, GPS and operating data of the vehicles. In 2006, Hytera Mobilfunk GmbH, formerly known as Rohde & Schwarz Professional Mobile Radio GmbH, received the order to implement a particularly powerful and expandable TETRA system.


SYTRAL in France

Market Segment

Light Rail

Project Time




The Solution

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    In close cooperation with our French system partner, we delivered a complete ACCESSNET-T TETRA system. Two redundant switching nodes ensure its efficiency and reliability. These core components control 17 base stations in the indoor and outdoor area. Depending on the location, they are equipped with a different number of TETRA carriers; overall, we are utilizing 45 TETRA carriers in the network. In addition, our solution integrates more than 1,000 radio terminals: On-board systems as well as handheld devices divided into call groups.
    Since data must be transmitted primarily, e.g. of signal generation and schedule monitoring, our solution rigorously meets the special requirements of SYTRAL on the data transmission via SDS.
    Our mobile radio solution also shows its special strength with respect to security: The pre-emptive priority in the communication hierarchy. This means: Even at highest network utilization, the network transmits important messages such as emergency calls, because the network assigns them the "rightof-
    way" over less important radio communication.
    At the same time, each call group participant is kept up to date, even if the participant could only connect at a later time. In short: Every network user always knows what he or she has to know.


The Results

Convincingly implemented

The public urban transit in the Lyon greater metropolitan area transports 1.2 million passengers every day. Consequently, the reliability of the vehicles in use and the communication technology has top priority. SYTRAL's new TETRA system transmits GPS and operating data of its busses and trams to the
control centre, transmits schedule information and enables communication between train drivers, bus drivers and control centre.
The data volume is high, the ACCESSNET-T network developed by us dimensioned with corresponding size, powerful and redundant. It secures a stable, fault free radio coverage, points with extreme robustness and flexibly adapts to all individual requirements of the customer.



Resources for a large number of SDS transmission through the use of secondary control channels (SCCH)
Late-entry function for call group participants who join ongoing group calls
Emergency call to different destinations
Packet data service

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