The DoT is understood to be in the process of preparing a new set of show cause notices against Airtel, Vodafone and Idea Cellular for allegedly violating 3G service norms.
"Draft Show cause notice for 'giver' licencees (telecom operator) for violation of the UAS licence (permit for offering telecom services) conditions by allowing use of their 3G spectrum under the garb of 3G ICR (intra-circle roaming) ...Has been attempted," a DoT source said.
The source further said: "Initially the notices have been attempted for UAS licences of Idea Cellular, Vodafone and Bharti only."
No comments on the issue were immediately provided by the companies concerned.
The notices being worked out by DoT are for alleged violation of licence conditions by Idea in Jammu and Kashmir circle where it allowed Vodafone to access its spectrum to offer 3G services.
The Department is also readying notices for violation by Vodafone in Delhi, Chennai, Uttar Pradesh (East), Haryana, Maharashtra, Tamil Nadu (excluding Chennai) and Kolkata service areas.
Bharti Airtel is likely to be served notice for violation in Assam, Bihar, Karnataka, Mumbai, UP (West) and West Bengal. Bharti Hexacom, a joint venture of Bharti Airtel with state-run TCIL, is also likely to be issued notice for violation of licence condition in Rajasthan service area.
The DoT had earlier issued 'taker' notice to Bharti Airtel, Idea Cellular and Vodafone for alleged violation of licence condition in the name of 3G intra-circle roaming agreement.
The 'taker' notice was for accessing the 3G spectrum of other player where the company did not had the airwaves for offering 3G services to their customers.
The 'taker' notice has been challenged by the companies and the matter is sub-judice now.