Memberships
- Mr. Trehan is an active Member of Indian Science Congress Association. Twice elected as the Chairman of the Engineering Sciences Section of the Association, he founded Delhi Chapter of Indian Science Congress Association (ISCA) in1995 and was its Convener till 2007. He is now Chairman of the Chapter and under his leadership the activities under taken by the Chapter have been appreciated by all concerned.
- He has also been a Member of Technology Information Forecasting and Assessment Council (TIFAC) of Dept of Science and Technology, Govt. of India.
- Honorary Fellow of Institution of Electronics & Telecommunication Engineers.
- Mr. Trehan has been Member of the Advisory Panel of Telecommunications of the Planning Commission.
- Mr Trehan has been the President of Indian Association for Productivity, Quality & Reliability which is affiliated with International Statistical Institute.
- As Member of the FICCI (Federation of Indian Chambers of Commerce & Industry) Joint Business Council, International Chamber of Commerce, and Indo- American Chamber of Commerce, Mr Trehan was part of several delegations to Holland, Spain, Portugal, Japan, USA and France in late 1980s and early 1990s. Was also member of the delegations accompanying the Prime Minister to Japan and France in early 90s