I. Introduction
PROVIDING wireless data services in the railway environment will become increasingly important for train operators and train constructors in the upcoming years. The deregulation of the passenger and cargo rail market will lead to the reorganization of many incumbent rail operators. Reducing the costs will involve optimizations in the current operational processes and gaining extra revenues will require offering new (interactive) passenger services. These indicated changes can gain a lot from the implementation of wireless data services, ranging from network and train control data, surveillance, crew services to passenger Internet traffic.