A spectrum of uses

V. SRIDHARTHOMAS CASEY Updated - June 05, 2011 at 07:17 PM.

Handy Internet: Students check results on the mobile. - Photo: K. Pichumani

While opinions vary on whether operators are facing a real spectrum crunch or are not utilising the allotted spectrum effectively, the Ministry of Communications and IT must look beyond the constant tussle with Defence over the release of additional spectrum for commercial mobile services.

It is not hard for us to imagine that given a suitable environment, mobile data and Internet service penetration in India will scale new heights, much as mobile voice has done.

According to recent research, the number of mobile Internet users has jumped from eight million last year to 25 million, and about 49 per cent use mobile only for Internet access. What can the Ministry and the Telecom Regulatory Authority of India (TRAI) do to enable India to take a lead in the adoption of mobile Internet?

Many countries are moving towards a technology-agnostic spectrum policy. The European Union has embarked on re-farming the traditional 2G spectrum in the 800 and 900 MHz bands to deploy 3G or even 4G networks with relatively higher spectral efficiencies, especially for data services. In India, as there is no level playing field for the 2G and 3G operators, we have mandated specific technologies (read 2G in 900 MHz and 3G in 2,100 MHz) for each spectrum band.

The new telecom policy should pave way for a technology- and service-agnostic roadmap for spectrum management and address the use of 900 MHz for 3G services. This is expected to resolve the spectrum bottleneck in dense urban areas with minimum cell sites, thanks to the good propagation characteristics of 900 MHz radio frequencies, including better in-building coverage and quality of service.

The second alternative is to review the Ultra High Frequency (UHF) band traditionally used for terrestrial TV broadcasting. Contrary to many other developed countries, in India there is high penetration of cable TV and direct-to-home digital satellite TV, even in rural areas. The terrestrial over-the-air broadcasting is mainly done by Doordarshan. Hence, there is a clear economic motivation for the Government to switch to digital terrestrial transmission, thus releasing the 700 MHz band — commonly referred to as the “digital dividend spectrum” — for commercial mobile services.

Though there seems to be an initiative on this front by the Department of Telecommunications and TRAI, the pace needs to be quickened. Broadcast services such as Mobile TV can be effectively provided on this band. As the US and most of EU plan to release the abovementioned spectrum band, the compatible equipment and handsets are expected soon in the market at relatively lower prices. India can jumpstart this evolution and become a pioneer in the implementation of digital dividend.

Under the third option, the Government can allow the development of a range of secondary markets. With no operator given nationwide allocation of 3G/ Broadband Wireless Spectrum (BWA), users are expected to pay hefty roaming charges.

In the simplest form, the Government should allow “national roaming” wherein a subscriber of Operator 1 can hook on to the network of Operator 2 wherever the former has no network, through an appropriate spectrum and capacity sharing agreement. The user will be treated as an “in-net” subscriber and no roaming charge will apply. This is allowed in many EU countries. This method promotes sharing of scarce network resources and improves utilisation.

Other approaches range from allowing Mobile Virtual Network Providers access to under-utilised spectrum of network operators; allowing network operators to share spectrum amongst themselves in a manner that promotes efficient utilisation; and, finally, opting for the Dynamic Opportunistic Spectrum Sharing methods, which are being deployed on an experimental basis in the US, wherein any service provider or user can opportunistically seize vacant spectrum blocks, either licensed or unlicensed (as in the case of TV white spaces that exist between adjacent TV channels) in a non-interfering way.

In the US, the Federal Communications Commission has designated eight entities, including Google, for managing such TV white space spectrum databases. The cognitive radio-based systems that embed detection of such vacant spectrum blocks using spectrum databases, though currently at an incipient stage, are expected to completely overhaul today's “command and control” regime of spectrum management.

The Government could think along these lines and provide a roadmap that can help the industry plan better. Tools such as Spectrum Management System for Developing Countries (SMS4DC), developed by the International Telecommunications Union, should be used by the Wireless Planning and Coordination Wing of the Department of Telecommunications. On the other hand, operators should welcome the above initiatives and embrace newer technologies that can enable us to network and communicate better, and hence prosper in the knowledge- and service-based century.

(Dr. V. Sridhar is Research Fellow, Sasken Communication Technologies, Bangalore, India and Thomas Casey is Research Scientist, Department of Communications and Networking, Aalto University, Finland. Views are personal. )

Published on June 5, 2011 13:07