Japan's SoftBank Group is ramping up its R&D with a pair of initiatives aimed at improving network efficiencies with Chinese vendors ZTE and Huawei.
Specifically, Huawei signed a memorandum of understanding (MoU) with SoftBank to cooperate on verification testing, technological evaluation and R&D of TDD+, which it describes as a 4.5G technology based on LTE TDD.
SoftBank took the lead in deploying TDD-capable Advanced eXtended Global Platform (AXGP) networks in Japan using its TDD spectrum. The TDD+ research cooperation with Huawei enables SoftBank to increase the frequency resource efficiency on the AXGP networks by about five times, the companies said.
"The technology involved in this cooperation will become the next-generation network development trend," Keiichi Makizono, senior vice president of SoftBank, said in the press release. "Now, SoftBank is planning to construct the next-generation mobile network. Therefore, our cooperation with Huawei on 4.5G technology is quite meaningful."
Since its first global commercial use in 2011, LTE TDD has seen the number of subscribers reach 200 million. The deployment of TDD+ enables carriers to explore new revenue opportunities and increase the revenue of mobile broadband services before 5G becomes available. Multiple carriers from China and Europe are also planning to introduce TDD+ on their networks.
David Wang, president of Huawei Wireless Network Product Line, said TDD+ helps increase the spectral efficiency and decrease the total cost of ownership (TCO). It also creates new services and provides a communications environment able to adapt to user demands. "Huawei will continue working on innovative technologies and strive to build a more interconnected world in cooperation with SoftBank," he said in the release.
Separately, ZTE said it also signed an MoU with SoftBank to collaborate on research and development on "Pre5G" mobile communications networks technology. Under that MOU, the two companies will cooperate on R&D, evaluation and verification of mobile communications solutions based on ZTE's Pre5G technology, including massive MIMO (multiple input multiple output). The agreement builds on existing cooperation between SoftBank and ZTE on technologies including massive MIMO, ultra-dense networks (UDN) and multi-user shared access (MUSA).
ZTE says its massive MIMO base stations have the capability to support more than 100 antenna elements and provide higher space division multiplexing gains than traditional 8-antenna base stations without changing existing terminals or air interfaces. With ZTE's massive MIMO base station, up to eight users can transfer data simultaneously.
Massive MIMO technology provides higher, farther and deeper coverage than traditional LTE technologies while lowering base station energy consumption, ZTE notes. These advantages can greatly improve the performance of existing AXGP networks. In a prototype demonstration, "the Pre5G Massive MIMO base station achieved an outstanding result in multi-user 3D coverage far beyond expectations," the company said.
It's unclear how much SoftBank will be able to apply its learnings with Huawei and ZTE to what it's doing with Sprint (NYSE: S) in the U.S. "We collaborate closely with SoftBank on network best practices and we are always looking at new ways to unlock the full potential of our network and improve the experience for our customers," Sprint said in statement via email to FierceWirelessTech.
Former SoftBank network manager Junichi Miyakawa joined Sprint as its technical chief operating officer in November, and in a blog post earlier this year, he said SoftBank's Top-Gun team of engineers is working with Sprint regional teams to share experiences and know-how. A key learning from SoftBank was the development and implementation of what he called "Operations Tools." While no network is failure-free, it's important to detect failures immediately and act quickly. The automated detection and self-learning functionality developed and introduced at SoftBank are features being introduced at Sprint as well.
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