Metro-North Railroad telecommunications infrastructure project

Metropolitan Transportation Authority Metro-North Railroad (MTA MNR) is one of the largest commuter line in the United States, providing more than 200,000 customer trips each weekday and some 62,000,000 trips per year. MTA MNR has an existing voice and data communications infrastructure consisting of older fiber optic equipment, copper cable plant and leased lines used for voice and data transmission services that are central to the day-to-day operations of the Railroad. The existing infrastructure has exceeded its useful service life, and in some cases reliability of certain network elements is poor. To accommodate existing and projected voice and data communications requirements of the railroad a hybrid telecommunications network has been engineered combining several widely deployed technologies. The network design is standards-based and provides a scalable platform that will provide a migration path for the future. This paper focuses upon the design process used at MNR and the rationale behind key decisions reached by the design team that led to the selection of the technologies and topologies utilized in this novel hybrid network.