In some markets, such as India, spectrum sharing might be essential, not simply helpful. The immediate issue is the ability to share frequencies supporting mobile services across 2G, 3G and 4G networks.
Efficiency and cost are the drivers. Larger blocks of spectrum simply are more efficient, able to deliver more volume in any fixed amount of spectrum. Also, by combining spectrum holdings, partners sharing spectrum often can reduce capital investment.
So far, at least two Indian mobile companies are talking about sharing their spectrum. State-run telecom operator Bharat Sanchar Nigam Ltd (BSNL) is in discussions with MTS, the Indian unit of Russian telecom company Sistema, for fourth generation Long Term Evolution services across the country.
Other forms of spectrum sharing include methods to allow Long Term Evolution networks to share spectrum, ways for LTE networks to use Wi-Fi spectrum, TV white spaces and new proposals to allow commercial users access to spectrum licensed on a primary basis to non-profit government entties.
The Telecom Regulatory Authority of India (TRAI) recommended allowing mobile operators to share spectrum, so long as all the sharing parties own licenses in the same bands (800 MHz, 900 MHz, 1,800 MHz, 2,300 MHz and 2,500 MHz).
In other words, two or more operators with spectrum in the 800 MHz band, for example, could agree to pool their respective spectrum holdings to create larger or more-contiguous blocks of spectrum.