However, before it changes the licence conditions to accommodate number portability, the department will initiate a fresh round of discussions with mobile phone operators and may fine-tune some of the suggestions made by Trai. DoT officials said these discussions would be held well before the deadline.

Number portability allows cellphone subscribers to switch service providers without changing their numbers. In general, telecom operators have opposed it, stating that the process will involve huge investments, to the tune of Rs 18,000 crore, for implementing number portability on a national scale. In fact, the Cellular Operators' Association of India (COAI) had even conducted a consumer survey which showed that mobile phone subscribers did not accord high priority to number portability.

In its recommendations, Trai had suggested that number portability be implemented in a phased manner - first in the metros and category A circles, and then in the B and C category circles within a span of six months. To enable operators recover their cost, Trai had suggested that subscribers porting their numbers be charged a one-time fee of Rs 200. This way the operators would be able to recover their investments in a period of three to five years, Trai had said.

Another objection of the operators to number portability was that Trai had suggested number portability only in mobile services and not in fixed line services.

Mobile companies had suggested that number portability must be first implemented in fixed line services since 95 per cent of landline subscribers are with the incumbent operator Bharat Sanchar Nigam.

Trai, however, had said that implementing number portability in fixed lines is not feasible right now.

It is not clear yet whether there would be a change in this stance after DoT completes its discussions with the operators.

Mobile number portability has already been implemented in places like Hong Kong, the UK, Australia, the US, Germany, France, Netherlands and Singapore.

Even Pakistan, which has mobile penetration of a mere 6.9 per cent, is planning to introduce number portability.