DB Regio AG is a subsidiary of Deutsche Bahnk which operates short and medium distance commuter train services in Germany . Some states have awarded long-term contracts to DB Regio. The headquarters of DB Regio in Frankfurt is responsible for business development and focuses on framework and service functions for regional units in the conclusion of transport contracts and tenders. In addition, it supports regions in the areas of price and revenue management, marketing and traffic planning. S-Bahn Berlin, Hamburg, Munich, Rhein-Main and Stuttgart are coordinated and controlled by the headquarters.