NEW BLOG: So far, TD-LTE has been something of a ‘niche’ technology, as its sibling FDD LTE has been more widely deployed by operators moving to 4G. But the list of backers of TD-LTE – China Mobile, SoftBank, Vodafone Group, Bharti Airtel and others were involved at the formation of the Global TD-LTE Initiative (GTI) – indicates this isn’t going to be another WiMAX.
With the Chinese authorities commercially licensing 4G services late last year, and operators worldwide keeping up the pace of new network launches, 2014 has the potential to be the year that TD-LTE makes it to the big time.
From the outset, GTI has talked-up the importance of TD-LTE interoperability with FDD LTE, to avoid a similar situation to WiMAX, where a technology – regardless of its capabilities – ended up being something of an evolutionary dead-end. Indeed, TD-LTE is being seen as the path forward for many WiMAX players, who are looking to make the most of the spectrum they own while rejoining a more mainstream technology path.
Deploying TD-LTE does offer a number of advantages for an operator. In many cases, they already own suitable spectrum which is lying fallow. And spectrum suitable for TD-LTE is often less expensive than the paired spectrum needed for FDD LTE services, making it a much more attractive proposition from a cost viewpoint.
It seems likely that with the technology already at a state where it is enough of a proven concept to attract new players, many new TD-LTE rollouts will come from operators which already have an FDD LTE presence or, as in China, where FDD has yet to be licensed, but where operators are looking to support both technologies (as China Unicom and China Telecom have pledged).
Indeed, China Telecom has already said that it will be looking for much of its network investments in the near future to support both technologies. The company became the 100th operator member of GTI when it joined earlier this year.
But so far, there has been little evidence of operators supporting both TD-LTE and FDD LTE, and where a company has both, these have often not been fully integrated – for example with a mobile operation focusing on FDD, while a separate wireless business has shifted from WiMAX to TD-LTE.
In many cases, FDD LTE is being used in bands such as 800MHz and 1800MHz which, while offering a number of advantages for first movers (primarily in terms of coverage characteristics and device availability), also have constraints in terms of capacity.
Supplementing this with TD-LTE using higher-frequencies in high-traffic areas will enable operators to take the best from both worlds.
Carrier aggregation across TD-LTE and FDD LTE networks is set to follow in the not-too distant future, giving operators the potential to offer seamless, high-speed services across the network flavours. At Mobile World Congress this year, Huawei and Vodafone Group demonstrated an LTE-Advanced network using 3 FDD carriers and 1 TDD carrier, delivering potential download speeds of 500 Mb/s.
And last month, Huawei said it had worked with China Mobile to verify “multiple core TD-LTE-Advanced technologies”, including TD-LTE and FDD LTE carrier aggregation, offering theoretical peak rates of 250 Mb/s.
Beyond China, there is also the potential for TD-LTE and FDD LTE convergence. In Japan, for example, the regulator is expected to issue the country’s mobile operators with 3.5GHz spectrum, which will be well suited to TD-LTE. While Japan has been one of the bellwhethers for TD-LTE through SoftBank, the new spectrum will further open the market for this technology.
And while China Mobile is widely perceived as being one of the lynchpins of TD-LTE, the company also has some experience of FDD through its Hong Kong arm, which has deployed both technologies. This will stand it in good stead should it decide to support both in its home market.
Next month, in line with Mobile Asia Expo, GTI will hold GTI Asia Conference. While it will be good to hear about the progress of the technology in China, it would also be nice to hear some new voices providing an update on their plans for the technology.
The editorial views expressed in this article are solely those of the author(s) and will not necessarily reflect the views of the GSMA, its Members or Associate Members.