The arrangement, which has no financial implication, is for only 45 days. Through this understanding, Airtel and Vodafone will get some time to deploy their networks in their newly alloted frequencies and their services will not disrupted during this period.
"For the convenience of customers, we have agreed to let Airtel and Vodafone use the spectrum up to January 15. The decision was taken in cognizance with the Department of Telecom," a Idea Cellular official said.
Idea will be alloted 5MHz block in 900MHz spectrum won by it in the last auction held in February, on November 30. It at present holds no airwaves in this band
Airtel and Vodafone at present hold 8MHz spectrum each in premium 900MHz band in Delhi, but they have to vacate them and shift to their newly acquired frequencies in 900MHz band.
In the auction, Airtel could win back only 6MHz and Vodafone 5MHz of spectrum in the same band.
The licences of Bharti Airtel and Vodafone are expiring in Delhi on November 29.
The two companies also bought some spectrum in 1800MHz band to make up for spectrum they lost in 900MHz band.
Mobile signals transmitted in 900MHz band cover almost double area compared to signals transmitted in 1800MHz band.
These operators have about 20 million mobile subscribers on their networks in Delhi or in other words 45 percent of the total subscriber base here.
Trai had earlier recommended that operators be assigned spectrum 18 months before expiry of their licences so that they can make necessary changes in their network without compromising on quality of service.