"We hope to come out with the final guidelines on interconnection norms in the post-unified regime in about 15 days... Telephone numbering scheme may also undergo some change," TRAI member DPS Seth said in New Delhi.
In the meantime, all the operators should continue to operate on the existing interconnection agreements, he said.
TRAI has received complaints from basic operators on the issue, Seth said, adding the service providers have sought the regulator's intervention in this regard.
Meanwhile, BSNL on Wednesday refuted allegations it was blocking calls.
"We are not blocking any calls. We have just sought instructions from DoT and TRAI on Interconnection Usage Charges (IUC) arrangement," BSNL chairman and managing director Prithipal Singh said.
Singh's comments come in the wake of reports that BSNL has been blocking incoming calls from Reliance, and seeking changes in the interconnection norms in line with the new Unified Access regime.