RCA Onboarding

Aatish Mishra
Aatish Mishra
Last updated 
This document aims to assist the reader to understand the purpose and working methods of RCA (Reference CCS Architecture).

Recommended start is a short introduction video:
RCA In a nutshell (subtitled).mp4 25.6 MB View full-size Download

What is RCA?
  • RCA: Reference Control Command and Signalling Architecture 
  • RCA is an initiative driven by railways organized in EUG and EULYNX, based on the RCA White Paper published in summer 2018. 
  • The RCA initiative strives establishing a trackside reference architecture resulting in a substantial improvement in cost, capacity, safety, reliability of the CCS system. 
  • RCA starts with radio-based ETCS cab-signalling and EULYNX interfaces and adds a harmonized architecture with clearly defined interfaces leading to an upgradable system with interchangeable components. 
  • RCA includes the game-changers such as ATO, moving block, train-borne localization, FRMCS, and introduces additional innovations and higher degree of automation.
  • The scope of RCA has been illustrated below:

Scope of RCA

Goals of RCA:
  • Key goals as defined in the RCA White Paper:
    • Lower Life Cycle Costs
    • Establishment of a single modular framework that can be used by IM's for constructing their own CCS systems.
    • Easier and cheaper migration solutions
    • Allowing various requirements of factors such as availability, safety, etc.
    • Safe Investment - Allow future innovation, upwards and downwards compatibilty, standardized interfaces prevents deviations from suppliers. 

Impact of RCA Goals 60.3 KB View full-size Download

Impacts of RCA from a Business Standpoint:
  •  Increased capacity with reduced investment in infrastructure such as tracks or points.
  • Onboard Localisation/Full Supervision allows for better safety levels and precise customer information.
  • Increased Security due to it being included in the system design from the start.
  • Energy savings in terms of avoided braking or reduced CO2 emissions.
  • Increased speed of rollout to cope with the need of replacement of existing systems.

RCA, OCORA and the game-changers:
  • RCA: Focus on modular CCS Architecture for radio-based ETCS and game-changers.
  • OCORA: Focus on modular on-board CCS architecture.
  • EULYNX: Providing specifications for control trackside assets .
  • ERTMS: Incorporates game-changers such as localization, FRMCS.

RCA incorporates EULYNX, ERTMS and OCORA 39.8 KB View full-size Download

RCA Deliverables
  • The main deliverable of RCA will be a set of interface specifications for the defined RCA subsystems. 
  • The RCA specifications may be used as tender templates for infrastructure managers (IMs) building/procuring an RCA-based system. 
  • Supporting material helping to understand the concepts and capabilities of RCA, as well as planning of RCA subsystems, will also be available in addition to formal specifications.

The latest RCA deliverables can be publically accessed here:

A more detailed document explaining RCA and its clusters can be found here

For extra reading on RCA please refer to below links:
  1. RCA and EULYNX
  2. RCA and System Pillar
  3. Realisation of RCA Goals (for more information of RCA goals and measures)
  4. Rethinking the heart of Railway Operations
  5. Command and Control 4.0
  6. Glossary of Terms and Abbreviations (from RCA Gamma)
  7. List of FAQ's (from RCA Gamma)
  8. RCA White Paper 
  9. RCA Wikipedia Page
  10. An Application of RCA: Start of Mission

Detailed overview on  RCA Clusters:
For more information on each cluster please visit the following links:
  1. Architecture
  2. Migration
  3. Digital Map
  4. Operational Harmonization
  5. Modelling and Tooling
  6. Security

Overview on EULYNX Clusters
  1. DataPrep (DP)