Time for TD-LTE

John C. Tanner
09 Jun 2010
00:00

Ever since the International Telecommunication Union created its IMT-2000 family of 3G technologies ten years ago, 3G has come in two basic forms: FDD and TDD. FDD offered separate spectrum bands for uplink and downlink traffic, while TDD offered upstream and downstream traffic on the same band.

But while FDD-based technologies like W-CDMA and CDMA2000 dominated 3G rollouts (the former more so than the latter), TDD-based TD-CDMA remained generally unloved except by vendor IPWireless and its small customer base, while the other TDD option, TD-SCDMA, was China's homegrown technology that most industry players regarded as a China-only technology with no realistic chance of ever seeing deployment outside of China, although Taiwanese operators FarEasTone and Vibo Telecom began small-scale trials of TD-SCDMA late last year.

However, TD-SCDMA - which went fully commercial in China last year and is now available in 238 cities from China Mobile - is suddenly looking primed to go international in the form of its next-gen version, TD-LTE, which has the full backing of the 3GPP as part of its overall LTE standards effort. That doesn't automatically guarantee greater operator interest in TDD outside of China - where, like its 3G predecessor, TD-LTE is guaranteed a home. But the past couple of months have seen a flurry of announcements around Asia regarding TD-LTE's viability.

Not unexpectedly, China Mobile signed a deal in April with FarEasTone to jointly develop a TD-LTE trial in Taipei. Much more surprising was Qualcomm's announcement last month that it would enter the long-awaited spectrum auctions in India to bid for broadband wireless access (BWA) spectrum in the unpaired 2.3-GHz band, with the intention of using it for TD-LTE, rather than Wimax. Later that month, Japan's Softbank Mobile - which gained access to 2.5GHz TDD spectrum in March after acquiring a stake in failing PHS operator Willcom - said TD-LTE was definitely on the table as an option. And perhaps tellingly, as TDD vets like Huawei, ZTE, Motorola and Nokia Siemens Networks have been issuing progress reports on TD-LTE developments, Ericsson announced a tie-up with Datang Telecom to integrate Datang's TD-SCDMA RAN gear into its 3G portfolio, ostensibly to beef up its China business, but also to develop TD-LTE solutions.

Such is the sudden excitement over TD-LTE that it's not only expected to see rapid take-up once commercial deployments starting next year, but will also comprise a sizable chunk of the entire LTE market by 2014, says Mike Wang, NSN's general manager for Taiwan, Hong Kong and Macau.

"It took W-CDMA six years to reach 100 million subscribers, but LTE will hit that in four years, and we project that TD-LTE will account for 40% of LTE subscribers by that time," he told Wireless Asia.

What's going on here? What's TD-LTE got that its TDD ancestors didn't? Part of the answer lies in spectrum availability and changing market dynamics. However, a major key to the puzzle is, ironically, LTE's arch rival Wimax, which is not only helping make the business case for TDD in general, but - even more ironically - could serve as the platform for future TD-LTE deployments.

Pages

Follow Telecom Asia Sport!
Comments
No Comments Yet! Be the first to share what you think!
This website uses cookies
This provides customers with a personalized experience and increases the efficiency of visiting the site, allowing us to provide the most efficient service. By using the website and accepting the terms of the policy, you consent to the use of cookies in accordance with the terms of this policy.