What will happen to the spectrum held by the telecom companies when their license period is over?

The 20 years loicense period for the existing license will be over by 2014/15 for Airtel, Vodafone and by 2017 for MTNL and 2020 for BSNL. When the license period is over by 2014 for Airtel or Vodafone for any circle, what will happen to the spectrum held by them?

For the 2G GSM services, the spectrum is held by these Companies in 900 MHz band and 1800 MHz band.  As per the existing guidelines, the 900 MHz band spectrum has to be surrendered entirely on completion of the license period and if the Company wants it again, it has to  get it in the auction. The 1800 MHz band spectrum can be retained, but the Company has to pay the market rate (to be determined in the auction to be held in November 2012) for it. In case the Company does not want the 900 MHz spectrum once again on completion of its license period, it can get it replaced by 1800 MHz band spectrum by paying the market price. But in such case it has to replace its network constructed earlier for 900 MHz band spectrum with a new network suitable for 1800 MHz band spectrum.

Now the Finance Ministry wants that the 1800 MHz band spectrum also should be taken away from the Company on completion of license period and the Company has to get it back by participating in the auction. As per the argument of the Finance AMinistry, the towers need not be constructed by any telecom company now since there are separate tower companies from whom they can be taken on rent, and the active infrastructure requiring technology will not be required for more than 20 years since the technology is becoming obsolete every few years in telecom sector and hence any how it needs to be replaced every few years. The Cabinet has to take a final decision in this regard.