in 1984, he started assembling push-button phones in india, which he earlier used to import from a taiwan company, kingtel, replacing the old fashioned, bulky rotary phones that were in use in the country then. bharti telecom limited (btl) was incorporated and entered into a technical tie up with siemens ag of germany for manufacture of electronic push button phones. by the early 1990s, sunil was making fax machines, cordless phones and other telecom gear. sunil says, "in 1983, the government imposed a ban on the import of gensets. i was out of business overnight. everything i was doing came to a screeching halt. i was in trouble. the question then was: what should i do next? then, opportunity came calling. while in taiwan, i noticed the popularity of the push-button phone – something which india hadn't seen then. we were still using those rotary dials with no speed dials or redials. i sensed my chance and embraced the telecom business. i started marketing telephones, answering/fax machines under the brand name beetel and the company picked up really fast.". he named his first push-button phones as 'mitbrau'.