A single number '112' can be used for all emergency phone calls across the country including for police, fire and ambulance, telecom regulator TRAI proposed on Tuesday.br br Similar to the '911' all-in-one emergency service in the US, government can integrate all existing emergency numbers such as 100, 101, 102 and 108 into the proposed '112' helpline number, TRAI said in its recommendations on emergency number.