Cellular service companies are to levy users a subscription fee of around Rs 1,000 per month for autoroaming, but billing per subscriber is expected to shoot up considerably to at least on an average of Rs 3,000 per month, say industry sources, given the fact that those who opt for roaming per se, tend to be heavy cellphone users. Out of this, DoT will get Rs 2,000 per subscriber per month as its revenue share.

About 15-20 per cent of the one million cellular subscribers have opted for roaming. This niche is expected to switch over to autoroaming given its benefits, resulting in additional DoT revenues of Rs 350 crore even on a conservative basis.

These approximations have been extrapolated from trends in the growth of roamers in the World 1 Network, which commands a market share of 60-65 per cent currently. MaxTouch, Airtel, Modi Telstra, RPG Skycell, Birla-AT&T, Escotel, Hexacom, Modicom, Tata Cellular and Koshika Telecom form part of the World 1 Network.

DoT's revenue gains on the revenue front in an autoroaming scenario will come from increased inter-city cell-calls being made through an inter-face with it at STD rates. Cellular operators point out that "currently a lot of inter-city calls are not made today as callers have no clue where another cellphone holder is placed".

Inter-city calls will increase as they can be made without the current hassles of changing SIM cards for every circle and incurring additional charges on account of the same. "Under autoroaming, DoT will be able to reap the benefits of higher STD revenues as inter-city calls increase", said sources. In autoroaming, a subscriber can use the same number anywhere in the world. The roaming segment is estimated to bring in DoT Rs 150 crore in revenues as of today. This is based on a current average billing of Rs 1,000 per subscriber per monthfor roaming services.