IRSE L&SE - The Radio Access Network in the World's Largest CBTC Project

This presentation will centre on the 4LM project which is a signalling upgrade using CBTC technology (Communication-Based Train Control) for four London tube lines (H&C, Circle, District and Metropolitan).

The key focus will be on the Radio Access Network (RAN) a crucial subsystem of CBTC. This radio infrastructure enables real time communication between the onboard computers of the entire train fleet and wayside equipment throughout the entire railway.

The presentation will cover following topics:

• An overview of the project and the technology used

• The challenges we encountered and the solutions we applied

• Our approach to system validation and tuning

• The critical role of big data tools, including a look at our toolset

Julien PUYON CEng is an experienced systems engineer with expertise in the integration, validation, and commissioning of complex critical communication systems. Known for his data-driven approach, he leverages advanced software and big data analytics to solve intricate technical challenges. Julien has earned recognition for his contributions to international projects across industries such as railways and national grids, ensuring the successful delivery of both greenfield and brownfield projects.

Passionate about tackling complex challenges, Julien enjoys solving everything from tricky systems at work to assembling IKEA furniture without losing his sanity!

Currently, as a Principal Systems Engineer at HITACHI RAIL, Julien oversees the integration and validation of the critical communication system for the 4LM project. He is also a key contributor to the development of the big data platform that supports 4LM project.

This will be a hybrid presentation: The online part will be using MS Teams. Details will be sent before the meeting to those that register. Please register before 1700 on 25/9/25 for on-line access.

The face-to-face part will take place at Hitachi Rail's Quadrant House office, 4 Thomas More Square, Thomas More Street, London, E1W 1YW. There are only a limited number of spaces. Face-to-face registration closes at 1800 on 19/9/25.