Wimax now ...
The other key difference, says ZTE's Liang, is that TDD has a major champion that it didn't have before: Wimax.
"The Wimax Forum has been pushing their technology, which has led to releasing 2.3 GHz unpaired spectrum in many markets, many of them markets where LTE spectrum isn't yet available and may not be for some time," Liang says.
Which sounds like better news for Wimax than for TD-LTE. Both fixed Wimax (802.16d) and mobile Wimax (802.16e) have a considerable head start on TD-LTE in terms of commercial deployments and a fairly robust ecosystem. And while the GSM Association has repeatedly argued that cellcos need to focus on the LTE roadmap and not get distracted by "interim" niche technologies like Wimax, the Wimax Forum and its members have maintained that there's no reason to wait for LTE in any form when the demand for IP-based wireless broadband is there now.
"When Yota says they spent $12 million to get 350,000 subs, that's a customer acquisition cost of around $34," says Gruba of Motorola. "When you look at what it costs to acquire cellular subs, which is several hundred dollars, the message is 'win share now', because when a second competitor comes into that market, regardless of the technology they use, their customer acquisition strategy has to be much different. You've either got to offer more or be price-conscious."
Ashish Sharma, marketing VP for Wimax vendor Alvarion, adds that TD-LTE is a lot farther off than it looks.
"TD-LTE doesn't have the ecosystem in place, and you need at least four or five years for that to develop, which Wimax has already done," he says. "Also, the first market that will deploy it on any decent scale will be China, which is a different spectrum band [2.5 GHz] than other markets and has to be backwards-compatible with TD-SCDMA, which will fragment ecosystem developments."
... TD-LTE later?
Interestingly, however, the "Wimax now" argument has morphed into "Wimax now, TD-LTE later" as vendors who sell both Wimax and LTE - such as ZTE, Huawei, Motorola and NSN, among others - point out that Wimax and TD-LTE are currently not all that different in terms of hardware.
"There's about 80% to 90% technical overlap between Wimax and LTE," says Mohab Khattab, group VP of Business Development/Legal for wi-tribe. "Both are based on OFDM, both are all-IP, they can use the 2.3/2.5 GHz bands, they employ advanced antenna designs and have similar speed capabilities."