Roaming is the facility that enables mobile users to make and receive calls or send text SMS and access all other services even when they carry their mobiles outside the coverage area of their home network. As the subscribers move out of this zone their calls are automatically "handed over" to the network in the new area.

Currently different operators levy different roaming charges within the country. These can vary from Rs1.50 to Rs3 per call — made or received — depending on the network. There are no ceilings on such roaming rates.

TRAI's view is that despite competition in voice telephony segment of mobile services, the roaming services market does not have significant competition and that there are justifiable grounds for a review of the tariff structure applicable for roaming services as determined in 2002.

The service providers contend that it is not TRAI but market forces that should determine roaming tariffs. The public sector BSNL has joined service providers in demanding that they should be allowed to continue to charge higher outgoing all and SMS rates while under roaming.

Bharti Airtel has already communicated to TRAI that a ceiling on national roaming charges would lead to an increase in the overall tariffs. COAI contends that since the overall tariff for mobile services in India is the lowest since basic voice services are often provided at below cost tariffs, revenues from VAS are an important source of revenue compensation.

BSNL has justified the need to charge higher tariffs for SMSs when the subscriber is on roaming on the ground that SMS under roaming involves signalling network and the expense on clearing house service.

However, national operators with networks all over the country like BSNL, AirTel and Reliance too impose roaming charges even though they do not need to transfer a roaming subscriber to any other network. In most European countries there are no roaming charges.

TRAI had introduced a consultation paper on roaming last November. The key issue it addressed was whether, in the case of a subscriber using the roaming facility, the terminating network service provider should get only the prescribed termination charges, or whether there should be any revenue share between this provider and the network to which the subscriber is temporarily transferred. No final decision in the matter has been reached.

Consumers contend that they should only be charged the cost incurred by operators on providing roaming facilities.