The potential availability of devices that can support both TDD and FDD versions of LTE technology has taken a big step forward following news today that three of the world’s largest operators have conducted joint laboratory tests on the time-division duplex version of LTE (TD-LTE). The operators – China Mobile, Verizon Wireless and Vodafone – initially announced an LTE testing alliance at last year’s event. Twelve months on, Vodafone today released a joint statement noting that their laboratory tests have now proven that the technology is capable of operating effectively in both unpaired (TDD) as well as paired (FDD) spectrum. In the statement, it is claimed that this step is significant in the development of LTE “as a truly global radio access technology.”

China Mobile is planning on eventually migrating its 3G TD-SCDMA standard to next-generation LTE using the TDD version of LTE. Meanwhile, Verizon, Vodafone and most other mobile operators will use the FDD version. Given China Mobile’s position as the world’s largest mobile operator by subscribers, the need for the availability of interoperable devices that can support both versions is apparent. In the statement, it is noted that “a range of chipset suppliers including ST-Ericsson and Qualcomm are developing equipment capable of supporting both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) flavours of the LTE technology in a single device.” Moreover, the statement claims that “the trials are a step towards the goal of developing a single device capable of operating on TD-LTE technology in the case of unpaired spectrum or LTE FDD technology in the case of paired spectrum.”