From 2007 to 2014, he served as Director of ITU's Telecommunication Standardization Bureau, spearheading activities in areas including cybersecurity, climate change and accessibility. Between 2003-2006 he served as International Coordinator at the United Kingdom’s Office of Communications (Ofcom), and was Director of the UK Radiocommunications Agency from 1992-2003.
Johnson has an MSc and a BSc from the University of Wales, Cardiff. He is a Chartered Engineer, a Fellow of the Institution of Engineering and Technology, and an Academician of the International Telecommunication Academy. He is married with one daughter.