
Stefan Zehle
Diploma in Business Studies, MBA Chairman and CEO , United KingdomStefan is the CEO and the co-founder of Coleago Consulting. He has been working in telecoms since 1987 with experience in over 65 countries. Stefan is a director of a start-up mobile operator, and an expert in spectrum valuation and licensing.
Working in telecoms since 1987, Stefan Zehle was involved in the first GSM mobile network licence applications in Europe, Asia, Latin America, and Africa. He ran telecoms projects in 68 countries including 2G, 3G, 4G, and 5G. As the second person on the ground (Director of Marketing, Strategy & Regulatory Affairs) he played a pivotal role in launching Nedjma, the third Algerian GSM operator, launching new propositions transforming the market and introduced best practice interconnect agreements in Algeria. He has worked on over 90 spectrum licence valuation projects, spectrum auctions and beauty contests for mobile and fixed wireless access licences. The report “Estimating the mid-band spectrum needs in the 2025-2030 time frame” authored by Stefan for the GSMA became the most downloaded report in its history from the GSMA website. Other reports in the public domain include “Vision 2030 – Low-band spectrum for 5G”, “Mobile Services, Spectrum and Network Evolution to 2025”, “Sustainable spectrum pricing”, “The cost of spectrum auction distortions”, and “The benefits of technology neutral spectrum licences”. Stefan is a regular speaker at Mobile World Congress in Barcelona and over 70 telecoms, telecoms regulatory, and spectrum conferences. He is the co-author of “Guide to Business Planning”, published by the Economist. A native German speaker, Stefan is also fluent in English and French.
Education
City of London Polytechnic, UK
- Diploma in Business Studies
University of Westminster, UK
- MBA – Business Studies
Other team members

Mike Johnston
Managing ConsultantMike has over 25 years’ experience in telecoms and specialises in fibre network infrastructure and project delivery. He works on strategic development projects for government intervention to accelerate fibre delivery, technical M&A due diligence for private sector and financial institutions and business strategy and planning for telecom operators.

Dave Tanner
Managing ConsultantDave Tanner is an highly experienced senior engineering professional with 30 years of specialist technical and operational expertise in telecoms, specifically, wireless (2G-5G/ WiFi/ IoT), fibre and satellite.

Sebastiaan van den Deijssel
Managing ConsultantSebastiaan has over 15 years of professional experience in marketing, product development, sales, customer care, BSS/OSS, and business modelling for Telecom. He is one of the foremost experts in the field of MVNEs and MVNOs. He gained his experience in key roles within MNOs, MVNOs as well as MVNEs in Europe, Middle East, Africa, Caribbean and the USA.