Motorola wrapped the first phase of TD-LTE field trials with China's Ministry of Industry and Information Technology (MIIT).

For wireless companies, the step from 3G to 4G will depend on an upgrade to LTE (Long Term Evolution) technology. The version of LTE that most wireless companies anticipated using is designated FDD LTE; because it seemed inevitable, there had been little point calling out the “FDD.”

In recent months, however, another version of LTE – TD LTE – has gained the attention of first China, then other Asian and African wireless interests, and now even Europe is sniffing it out.

TD-LTE is appealing for several reasons, Motorola explained: the low cost of TDD spectrum that is particularly attractive to emerging and developing markets, operators' continuing need for more capacity and spectrum, and the ability to roam and hand-off between TD-LTE and FDD LTE networks.

In effect, Motorola explained, the ability to roam between FDD LTE and TD-LTE means operators can use TD-LTE networks to augment their FDD LTE network for more capacity or for other applications such as video broadcasting, while operators choosing to use TD-LTE as their "main" network can still offer their subscribers the ability to roam to other operators' FDD LTE networks in different countries.

The TD-LTE trial Motorola just concluded with MIIT included key functionality, performance and mobility test cases in a multi-sector, multi-site environment that lays a solid foundation for large-scale TD-LTE deployment.

Motorola tested downlink throughput up to 80 Mbps, demonstrated mobility and successfully accomplished handover with live applications.

Motorola said it is now ready to begin Phase II TD-LTE field trials with increased focus on applications and quality of service (QoS) in Shunyi, Beijing.