Informal conversations with the telcos and other ecosystem players suggest that the country might be going in for the convergence of both variants of LTE—TDD and FDD. Post the auction of 2300 MHz spectrum it had been a given that India would adopt the TDD version of the technology. However, this is no longer the case.
Post the recent auctions in the 1800 MHz spectrum bands, there is a strong movement towards adoption of FDD and consequently a convergence of TDD and FDD in the country. “It is expected that the band [1800 MHz] would enable new 4G operators to offer voice and enhanced data services and this has enabled the need for LTE TDD and FDD convergence in India. Convergence of TDD and FDD may be viewed in two parts, the ability to use the two bands to complement their use for better coverage and capacity utilization and the ability to aggregate the spectrum in both the bands in order to use them together to enable much higher throughputs,” said Amit Marwah, Chief Technology Officer, Nokia India.
While TDD has a strong push from the Indian and Chinese telcos, the larger ecosystem is clearly in favor of FDD. There is a global push for the telcos to converge the two technologies. For instance, China Mobile has attempted to use both the variants of the technology. In the US, ClearWire and Sprint are believed to be collaborating to offer a converged network to their subscribers. So the convergence would be good news for subscribers who would be able to use interoperable devices on the network.
“SK Telecom recently demonstrated the world’s first TDD-FDD carrier aggregation together with NSN and Korea Telecom. This demonstration has set a new benchmark for improved network capacity, coverage and speed. The breakthrough move from pure TD-LTE to LTE FDD-TDD convergence and carrier aggregation would be a book for Indian telcos and their LTE mobile broadband subscribers,” said Berge Ayvazian, Industry Analyst, Conference Chair and Senior Editor, UBM Tech in his recently published column on Light Reading India.
With the acquisition of the 1800 MHz spectrum in 14 circles in the recently concluded auction, Reliance Jio is also likely to adopt a convergence strategy. Having the two frequency bands—1800 MHz and 2300 MHz—means that the company can deploy FDD for coverage and leverage TDD for additional capacity in high traffic zones.
“We have been observing that all telecom operators including those who acquired 1800 MHz and 2300 MHz spectrum are banking heavily on data services and taking a holistic approach for making 4G even more affordable for users. This will add impetus to its uptake in India. In such a scenario, the complementary use of TDD-FDD holds all the more importance in this market,” elaborated Marwah of Nokia.
However, the convergence faces some unique challenges in India. The most prominent problem area is the fragmented allocation of spectrum and patchy distribution of contiguous 5 MHz spectrum, especially in the 1800 MHz frequency bands. Besides, the telcos would need to work towards offering affordable dual band 4G devices to the subscribers to increase the adoption of 4G subscribers.
Deepak Kumar, Founder Analyst at BusinessandMarket.net is of the view, “While the convergence of TDD and FDD makes good logical sense for operators but given that 4G is a greenfield opportunity in India, service providers would like to see through any such integration before the rollouts. So if they decide to first do the integration, then it would most likely further delay the rollouts.”
It is already four years since the auction of Broadband Wireless Access (BWA) spectrum in 2010. Only Bharti Airtel has launched LTE services in a few cities. The anticipation is that the telcos will launch 4G services later this year since the ecosystem is slowly developing. However, the convergence might further delay the launch of the high-speed 4G services.