In-building networks may get more spectrum

In a move that could alleviate the tremendous crunch for spectrum, the department of telecom is considering the possibility of allocating 3 MHz in the GSM 1800 band and 1.25 MHz in the CDMA 800 band exclusively for "in-building" use nationwide.

It is also exploring the possibility of delicensing 5 GHz to 5.35 GHz spectrum for similar use by mobile service providers. For users, this means far superior mobile coverage when inside buildings.

Despite the high costs, the allocation of 3 MHz will enable operators to use this chunk of spectrum for mobile calls within large buildings.

"This is an expensive process, but can be used as an EPABX for very large buildings. Up to 1,000 mobile calls can be simultaneously supported on these frequencies," said a CDMA operator.

In a bid to ensure that the frequencies are not misused and also to prevent future cartelisation, the DoT may also incorporate clauses to prevent operators and internet service providers from using these frequencies.

Sources added that technology steps, if implemented, will address the concern over the tremendous increase in number of mobile towers, especially in cities.

Mobile companies are also quite keen for delicensing of the 5 GHz to the 5.35 GHz frequency, also called Wi-Fi spectrum, as this will enable them to incorporate fusion technology in their networks. Fusion permits calls to and from mobile subscribers within a building to be routed through the fixed network.

This technology permits an outgoing call from a mobile handset in a building to be carried on a Wi-Fi spectrum to the nearest fixed line network.

Similarly, an incoming call is carried through the fixed line network and transferred to the 5-5.35 GHz spectrum, to be received on the mobile handset.

The logic behind in-building spectrum is the estimation that over 60 per cent of mobile calls originate and terminate within buildings.

This solution has also been recommended by the Telecom Regulatory Authority of India. Besides, it has also been successfully deployed in some parts of Europe.

"In addition to saving scarce spectrum, operators do not have to incur huge network expenditures to incorporate this "" they only need specific equipment in the building for the routing process," said an executive with a service provider.

In fact, Reliance Infocomm has conducted trials of an in-building solution in Pune. Tata Indicom has also conducted a similar trial, among other operators, sources added.