A new report from Signals Research indicates that the transition from WiMAX to TD-LTE is occurring much more quickly than originally anticipated.
"For some operators, the full transition will take several years, but the point remains that they are already in the process of deploying LTE TDD. At the other extreme, some operators are literally ripping out their Mobile WiMAX network and switching everything to LTE TDD," said the report.
Signals cited KDDI subsidiary UQ Communications, which has 4.5 million WiMAX subscribers. The Japanese carrier's network uses 2.5 GHz spectrum and covers nearly 99 percent of the Japanese population.
In July 2013, UQ was awarded 20 MHz of TDD spectrum in the 2.6 GHz band, which is adjacent to its existing 30 MHz spectrum holding. Subsequently in October 2013, UQ switched on WiMAX 2.1 technology, which it has branded as WiMAX 2+. The service is compatible with TD-LTE, but UQ is not authorized to offer LTE technology in the 2.5/2.6 GHz bands.
"WiMAX 2+ is technically LTE TDD but for regulatory purposes the operator has to use the term WiMAX 2+," Signals noted.
UQ will deploy nearly 18,000 WiMAX 2+/TD-LTE sites on existing mobile WiMAX sites by year-end to cover 90 percent of Japan's population. Further, UQ expects to cover 95.8 percent of the population with nearly 39,000 WiMAX 2+/TD-LTE cell sites by the end of 2018.
The report also addressed Japan's SoftBank, which has 50 percent more TD-LTE sites (about 46,000) than LTE FDD sites (about 30,000). Sprint (NYSE: S) can potentially use the experience of SoftBank, its majority owner, to leverage the roughly 150 MHz of 2.5 GHz TDD spectrum it is now sitting on after acquiring legacy WiMAX operator Clearwire.
However, Signals said Sprint still needs to acquire lower-band spectrum under 1 GHz for coverage purposes. "It wouldn't get this spectrum by purchasing T-Mobile (NYSE:TMUS) or partnering with Dish Network (NASDAQ: DISH)," the report said.
Signals also noted that regulators in numerous countries are preparing to transition "fixed licenses" assigned to WiMAX operators to "mobile licenses."
According to the report, a major problem with this approach is that most traditional WiMAX operators "did not come close to providing ubiquitous coverage and the cell density wasn't adequate to support mobility." Therefore, Greenfield TD-LTE operators that are transitioning from WiMAX should be wary of promising full mobility to customers with TD-LTE smartphones.
"All things being equal, going from a nomadic/semi-fixed wireless service with a desktop CPE to a fully mobile service with handheld devices can require well more than twice as many cell sites to deliver the same level of performance," Signals noted.
- see this Signals Research report (PDF)
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