ESA title


  • ACTIVITYDemonstration Project
  • STATUSOngoing
  • THEMATIC AREATransport & Logistics

Objectives of the service

The objective of the proposed activity is to develop a demonstration of a hybrid satellite communications and terrestrial network for use on trains.

This Satellites for Digitalisation of Railways (SODOR) project will deliver pilot demonstrations of improved network connectivity for train monitoring and passenger broadband. The project aims to demonstrate how new constellations of communication satellites can seamlessly fill gaps in terrestrial coverage and provide additional capacity to improve safety and provide travellers with better connectivity.

CGI will work with IT partners Icomera, Isotropic and 5G3i, alongside Network Rail, and rail operators ScotRail, Northern and LNER, to explore how hybrid networks, based on multi-bearer 5G technology, can improve network availability while offering better value for money than existing solutions.

SODOR will deliver the following: 

  • Improved on-train communications for employees and passengers, with network aggregation for 3G and 4G and a roadmap for 5G, and a choice of satellite constellations dependent on bandwidth and location to ensure a reliable signal

  • Cost-effective communications, including tools to optimise network selection based on cost and performance

  • Operations and management portal

  • Internet of Things sensor solutions to support connected train monitoring

Users and their needs

User Needs

The target users of the service are Train Operating Companies in the UK and in the immediate term will be those directly involved in the project ScotRail, Northern Rail and LNER that have identified the following user needs:

  • Improve availability of communications for diagnostic purposes

  • Increase capacity of communications for all routes

  • Improve availability of Train location Information for rural routes

  • Provide a consistent wi-fi capability for passengers


The project will meet the following challenges in order to deliver the needs listed above:

  • Certification of New Developmental Technology - Electrically Steerable Antenna 

  • Novel Solution to deliver High Bit Rate use case for Passenger Wifi

  • Integration of Novel technologies to deliver High Bit Rate use case

The project has built a consortium of partners who specialise in the different key technologies needed to help address each of these challenges.

Service/ system concept

The SODOR Satellite Communication System (SCS) system will provide additional data connectivity within a parent communications system or network by means of SatCom terminals attached to trains or provided to portable (track-side) users. The SCS will provide Low Bit Rate (LBR) data connectivity services for sensors monitoring and voice comms, as well as High Bit Rate (HBR) services for applications such as Passenger Wi-Fi.

The Resource Planner will provide the ability to plan the Satellite connectivity for any train route and provide the best options based on the best availability,  optimising use of the services in order to provide high availability at an affordable price

System Diagram

The below diagram outlines the system its associated components.


Space Added Value

GEO and LEO Constellation Satellites will be used to provide both a gap fill and augmentation of the existing terrestrial GSM network. Satellite Communication will provide increase network capacity and improve availability through a variety of use cases including Business Critical Operations e.g. voice comms, and train location and the Passenger experience e.g. passenger wifi.

Although many trains already provide passenger Wifi and almost all provide communication facilities for the train crew, these generally rely on access to terrestrial broadband.  The Terrestrial network does not provide 100% coverage across all rail routes, particularly in rural areas of the UK and therefore cannot provide full support to Business Operations and Passenger Services. This is crucial because train crews need to be able to rely on communications being available in all circumstances when they may need them.  The public increasingly rely on applications with continuous access to the internet and so they expect this to also be available when using rail services. Satellite Services can provide the missing communications capability much more economically than expanding Terrestrial connectivity. Additionally, Satellite can also provide additional capacity for peak load and improve the overall network capacity.

Current Status

The user needs and requirements have been identified and reviewed with the stakeholders.  The team is working on identifying and mitigating project and technical risks as they proceed through the technical design stage ready to develop and test the solution. Design and development will take over as the primary focus for the next few months. 

Prime Contractor(s)


United Kingdom

Status Date

Updated: 28 November 2022