This paper was published in IRSE NEWS September 2017.

Railways are always increasing the number of network services to cope with emerging technologies. A quick fix solution that railways currently adopt is to deploy parallel networks over the communication backbone system to cope with the demand of emerging technologies like video analytics in closed circuit television cameras, Long Term Evolution 4G digital radio and communications-based train control. This basically means
adding a new box each time a new network service is required and the funding comes on top of the operational costs for maintaining the railway in the form of capital expenditure for an information and communications technology refresh. The drawbacks with these hardware-based solutions are:

• The hardware rapidly reaches end of life.
• They require reiteration of the design-integrate-deploy cycle with little or no revenue benefit.
• They require operational outages for deployment of changes or upgrades.

Telecoms service providers who are faced with the same set of problems every time there is a new network service to be launched are embracing the virtualisation and automation trends in information technology to perform network functions which are traditionally provided by hardware such as routers and switches.

The aim of this paper is to show how these software defined networks (SDN) can benefit the railway
networking environment to cope with constantly emerging technologies and become the platform for innovation.