Without using digital command and control systems ' focussed around ETCS ' it is not going to be possible to keep up with the rate of renewal of life-expiring signalling across the GB rail network. Digital railway, as the system of systems has been termed, presents significant benefits for the operational railway as well, even if it isn't a replacement for conventional capacity enhancement. However, delivering these technologies is immensely complex, and it has taken longer than initially envisaged to get the programme up to speed. This panel will dig into the challenges and recent successes with speakers from leading positions in this domain.