Anil Ambani for spectrum-efficient tech

After seeking the surrender of spectrum, Reliance Communications (RCom) Chairman Anil Ambani is seeking installation of frequency-efficient technologies such as synchronised network and FemtoCells that can be used at no additional cost. Ambani listed seven technologies to improve mobile network efficiency in the country.

In a presentation to the Department of Telecommunications (DoT), Ambani said that in synchronised network the towers were synchronised using global positioning system or suite. This technology helps in improving radio network capacity by 20 per cent.

Another technology suggested by Ambani is the dynamic frequency & channel allocation (DFCA), which eliminates possible frequency collision.

Usually, the frequencies used by two network nodes may cause interference to each other when the two nodes move too close.

To avoid this, there is a need to dynamically assign frequencies to network nodes. According to Ambani, DFCA enhances radio network capacity by 60-90 per cent.

Ambani further suggested the installation of 6-sector base transceiver station (BTS) in place of the present 3-sector BTS. The 6-sector BTS, an emerging technology for towers, doubles the capacity of 3-sector BTS in the spectrum.

Stating that this system nearly doubles network capacity, Ambani added that the group operated 200 6-sector sites through Reliance Communications (CDMA) and Reliance Telecom (GSM) services in the country. Vodafone used this system in Hyderabad, informed Ambani.

The fourth technology Ambani advocated for adoption is adaptive modulation rate (AMR). This technology increases network capacity by 150 per cent at no additional cost.

Even though, networks in the country are not AMR-compliant, the handsets being launched after 2003 are AMR-enabled. At present, there are over 110 million AMR-enabled handsets in use in the country.

Single antenna interference cancellation (SAIC) is another technology suggested by Ambani. This technology cancels or suppresses interference by means of signal processing without multiple antenna.

Ambani stated in his presentation that SAIC handsets were available in the market since 2004 and majority of Nokia phones were compatible with this technology. Nokia has a market share of 70 per cent in the country, and it would not be difficult for service providers to implement this technology.

FemtoCells, a new technology that boosts indoor coverage of mobile phone networks, thus reducing call drops and signal failures "� is another technology suggested by Ambani.

The technology also improves spectral efficiency by releasing BTS capacity for outdoor use. Over 100 million FemtoCells are expected to be operational by 2011.

Ambani has also suggested use of In Building Solutions such as splitters and couplers, radio frequency feeder and indoor base stations to help in saving spectrum.

He also quoted a Telecom Regulatory Authority of India (Trai) survey which stated that 70 per cent of calls in a cellular network were in-building calls.

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Seven technologies to save spectrum

Synchronised Network

Dynamic Frequency & Channel Allocation (DFCA)

6-sector towers

Adaptive Modulation Rate (AMR)

Single Antenna Interference Cancellation (SAIC)

FemtoCells

In Building Solutions