The European Switch

The increase of efficiency within wireless train control systems is essential. The circuit-switched technologies actually used will not provide the needed transmission quality for ERTMS/ETCS if the number of concurrent users increases as prognosticated until 2015. The promising solution might be the packet-switched approach of GPRS, but there are still a lot of open questions to be answered; mostly, the transfer delay of the GPRS network must be analyzed in detail. The next main important steps to establishing the whole GPRS-R simulation environment will be the integration and validation of the wireless medium access via the GPRS-R MAC/RLC module as well as the integration and validation of the GPRS-R air interface module. These two modules will provide, on the one hand, a detailed analysis of the possibilities of packet-switched GPRS regarding an efficient use of wireless communications channels and, on the other hand, significant values regarding the BER and transfer delay expected because of collisions and the characteristics of the air interface possibly having the highest impact of those parameters.