A little over a year ago the WiMAX Forum® launched the WiMAX 2.1 initiative with the goal of adopting a clear evolutionary technical roadmap for the WiMAX technology’s convergence with TDD LTE. Over the past year, the WiMAX Forum has been working with leading operators and ecosystem vendors to develop the business case and technology roadmap for WiMAX 2.1 or “WiMAX Advanced™”, based on IEEE Standard 802.16™.
Similarly, the XGP Forum was founded with the goal of defining a global specification to be adopted by 3GPP to make it possible for “PHS and AXGP” operators to share the ecosystem with TDD LTE1. The GTI (Global TDD-LTE Initiative) is now collaborating closely with the XGP Forum and the WiMAX Forum. This effort has resulted in significant progress with both WiMAX and PHS operators, equipment providers, and service providers, coming to an understanding that these technologies should be harmonized for the future 4G TDD architecture.
The ITU approved both LTE Advanced and WiMAX Advanced as IMT-Advanced technologies, and the WiMAX 2.1 initiative leverages the unique advantages of TDD spectrum along with other key attributes, such as Carrier Aggregation, 256QAM, and 8x8 MIMO, with a goal to reach a mobile downlink speed of 1 Gbps by 2017. WiMAX Advanced runs parallel to LTE Advanced, but is also a path to convergence with TDD LTE to enable operators to benefit from the economies of scale associated with a larger ecosystem of cost-effective TDD LTE devices. With the support of more than 140 members, the WiMAX Forum officially approved WiMAX Advanced as an extension of its technical network evolution roadmap during its most recent Board meeting in Washington, DC. The WiMAX Forum now has a plan in place for a smooth and cost-effective, backwards compatible transition to WiMAX Advanced for both network and subscriber equipment.
Operators in mature markets with access to additional spectrum have already begun deploying TDD LTE networks in parallel with their existing WiMAX networks. Now that its acquisition by SoftBank has been concluded, Sprint is accelerating the deployment of a new TDD LTE network while maintaining the existing Clearwire Mobile WiMAX network which serves millions of subscribers in the United States. With an average of 100 MHz of 2.5 GHz TDD spectrum nationwide and access to new capital from SoftBank, Sprint and Clearwire can devote 20 MHz of spectrum to manage the transition to support WiMAX and TDD LTE co-existence over a period of two years or more. In Japan, UQ Communications has also implemented plans to leverage newly awarded 2.5 GHz spectrum to upgrade its existing network from WiMAX to WiMAX 2+, to leverage WiMAX Advanced in support of TDD LTE devices. UQ launched WiMAX 2+ service on Oct 31, 20132.
On October 4, 2013, the Korean MSIP (Ministry of Science, ICT and Future Planning) outlined a policy for WiBro (WiMAX) operators to upgrade to TDD LTE3. In addition to the technical merits, the policy is based on the premise that the existing 1 million plus WiBro subscribers transition to WiMAX 2+ in the future. The ministry is providing support to enable WiBro services, which are serving special purposes in such fields as national defense, to co-exist in a niche market, while expanding to overseas markets by means of network establishment and technological development.
The WiMAX evolution to WiMAX 2+ in Korea, is expected to have a significant economic benefit over the next several years. Jung In-Joon, professor in the Department of Business Administration at Daegu University, published his report in June on the current status of TDD LTE and frequency management directions in the journal of the Korea Association for Telecommunications Policies. In the report, he claimed that the service sales that could be anticipated in 2019 would reach US$16.995 billion when harmonization is achieved. “If the 57 MHz frequency band that is allocated for mobile is used for TDD LTE, the service sales are expected to be increased by at least 400% and up to 2,000% during the same period,” he suggested4.
The Korean government also has its sights set on the potential global demand for TDD LTE. The WiMAX transition will drive local firms to boost their competitiveness in the 4G market. In this context, it benefits a national plan for the development of the TDD LTE segment within this year, which will cover the R&D of key TDD LTE technologies, research on next-generation equipment, such as 5G, and terminals, and the development of application service models.
As of Q1 2013, almost every one of the 477 WiMAX operators worldwide has embraced the WiMAX 2.1 initiative based on IEEE 802.16TM. With the success of WiMAX 2+ for UQ in Japan, the global TDD LTE transition presents a substantial business opportunity for equipment and system providers. The TDD LTE device market is growing at a rapid pace. According to industry analysts, China Mobile alone will procure more than 50 million TDD LTE terminals in 2014, including approximately 40 million smartphones and 10 million data cards.
In recognition of the significant economic benefits of having a common ecosystem, the WiMAX Forum is proactively collaborating with operators, equipment vendors, and regulatory agencies worldwide to facilitate the implementation of a WiMAX Advanced harmonization plan.