LTE TDD: Driving the Universal Nature of LTE – Whether That’s Understood or Not

Peter Jarich
Peter Jarich

If I can believe my desk calendar, it’s almost summer. With the longest day of the year fast approaching, my mind has turned to all of the usual topics: fireworks, hot dogs, bitter jealousy aimed at European colleagues who take four-week vacations, LTE TDD.

Okay, summertime and LTE TDD might not go hand-in-hand, but there are some real reasons the TDD implementation of everyone’s favorite 4G technology has been on my mind. Earlier this month, I spent some time with my consumer analysts out in Kansas City visiting Sprint; with LTE TDD at the foundation of Sprint Spark, you know the technology was a major component of the discussions with them. This week, I’m sending some of my team to Shanghai in order to catch up with our friends at ZTE. Along with Huawei (which we visited in April), ZTE is expected to benefit significantly from LTE TDD deployments in China over the next year or so; the two vendors won the lion’s share of China Mobile’s LTE TDD awards. This was long-expected and the scale won in supplying these networks is expected to benefit them, particularly if the other Chinese mobile operators follow suit.

You can see why I’ve been thinking about the technology, right? Great. Then let me throw in another wrinkle.

The idea that ZTE or Huawei are de facto LTE TDD market leaders, by benefit of being Chinese, positions the technology as fundamentally Chinese. At the same time, even singling out vendors as LTE TDD leaders positions the technology as something completely distinct from the FDD version of LTE. Is that fair? Is it accurate?


No vendor is going to turn down the revenue opportunities associated with LTE TDD. Likewise, no vendor would deny that China is a huge mobile broadband infrastructure and device opportunity as the domestic carriers move on LTE deployments. Regardless, both Huawei and ZTE sell solutions with value that extends beyond the borders of China. They’ve spent years building businesses – businesses with scale – outside of China. In the process, they’ve built reputations as global solution providers with the scale and capabilities to compete globally.

The same thinking applies to LTE TDD. Forget, for a moment, Sprint Spark. Forget the synergies Sprint claims from SoftBank’s experience with LTE TDD in Japan. Forget that the Global mobile Suppliers Association claimed 36 LTE TDD networks in 24 countries as of May. Forget all of the proof points that LTE TDD is a global technology, benefitting from an LTE foundation. From its inception, LTE was built as a global standard, ready to support diverse spectrum allocations – paired and unpaired, small or large bandwidth. Executing on this promise, however, requires operators and vendors to acknowledge it as a global – not just Chinese – technology. It needs to be understood as a technology benefiting from global scale and the broader LTE ecosystem. At the same time, none of this can detract from the benefits that come from TDD: ability to take advantage of low-priced, unpaired spectrum; dynamic allocation of downstream vs. upstream traffic; simpler MIMO and beamforming implementation. Add to that potential LTE TDD use cases such as LTE Broadcast and it’s a complex story to tell. Luckily, it’s more than just a “story.” It’s a reality that derives from being an integral part of LTE standards and the presence of unpaired spectrum allocations around the globe.

In other words, there’s a lot to think about here. That’s why, over the next few months, I want to take some time to explore the TDD version of LTE a little more: its position as a global mobile broadband technology; the device ecosystem behind it; the network infrastructure ecosystem behind it; the deployments already underway.

While there’s a lot to think about here, there’s one last thought I’d like to leave you with.

Years ago, as LTE deployments first began to take hold, TDD messaging was front and center. Operators with unpaired spectrum worked to drive the development of LTE TDD solutions. Vendors raced to prove out their capabilities and the applicability of their core LTE R&D to both duplexing schemes, TDD and FDD. This all makes sense; where LTE was designed to be a globally applicable mobile broadband technology from the beginning, you’d expect to see a focus on all aspects as rollouts began. More recently, however, that messaging has somewhat died down, particularly in the face of impending LTE TDD launches in China and the success of FDD deployments elsewhere. There’s a risk, then, that old misrepresentations (LTE TDD as Chinese) could resurface and once-heralded advantages (LTE foundation, efficient spectrum use, global spectrum availability) get ignored.

As we enter the summer months, that quiet period between the trade shows of the spring and those of the fall, we’re also entering what might be considered the second wave of LTE deployments; early, pioneering deployments have given way to mainstream rollouts, but there’s still plenty of work left to be done – plenty of territory yet to be covered. As vendors, operators, and everyone else begin polishing up their LTE messaging for the rest of the year, it’s probably best if we’re all on the same page. I may not be able to clear up everything, but it sure seems like a good time to try.

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