Unhappy over the communication ministry's decision to allot addition spectrum based on regulator Trai's formula, CDMA mobile operator Reliance Communications [Get Quote] on Thursday served a legal notice to the government to freeze allocation of airwaves to existing players.

The notice came in the wake of government accepting Trai's recommendations to award spectrum to mobile operators and deciding to file an affidavit in the Delhi High Court.

RCom also said the government should enforce Telecom Engineering Center's proposed subscriber base for allocation of spectrum, which was earlier accepted by DoT 'in-principle'.

TEC norms were much more stringent than those proposed by Telecom Regulatory Authority of India. TEC had raised subscriber base by up to 15 times while TRAI had suggested up to six times increase in the users base.

The notice has been filed to ensure that excess spectrum held by GSM operators is being returned, RCom said in a statement. It said GSM operators should immediately return over 50 MHz of spectrum being hoarded by them free of cost and beyond their entitlement of 6.2 MHz.

RCom had on Wednesday said the government's decision to accept TRAI's norms for allotment of additional spectrum tantamount to succumbing to the pressure tactics of GSM lobby.