Dec 13, 2018
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At this week’s 3GPP plenary meeting in Sorrento, Italy, an anticipated, but still groundbreaking decision was made — to include support for 5G NR unlicensed spectrum in 3GPP Release 16, kicking off the work item. As we are about to see commercial mobile 5G launches in the coming months, it is easy to get excited about the prospect of soon having a 5G smartphone in your hand, but I find it equally exciting to see what is coming next.
There are many exciting projects in the scope of the upcoming 3GPP release 16, such as industrial IoT, private networks, positioning, cellular-V2X, broadcast, enhancements to mobile broadband, and mmWave evolution, just to mention a few. However, the one that I want to highlight in this blog post is 5G NR operating in unlicensed spectrum, which is one of the cornerstones broadening the 5G vision to evolve and expand the ecosystem and transform industries.
5G NR unlicensed spectrum (NR-U)
Licensed spectrum is essential for cellular communication and that will continue in the 5G era especially for the traditional mobile broadband services launching next year. But when it comes to extending 5G into new markets, I think the opportunities generated by adding support for unlicensed spectrum cannot be overstated.
The NR-U work item that was just approved by 3GPP supports both the existing 5GHz unlicensed band as well as the new "greenfield" 6GHz unlicensed band. In subsequent releases, I expect the addition of other unlicensed and shared spectrum bands, including mmWave. The work item covers five scenarios with functionalities such as Carrier Aggregation (within one eNodeB), dual connectivity (across two eNodeBs), LTE anchor in licensed spectrum, 5G NR anchor in licensed spectrum, uplink only in licensed spectrum, downlink only in unlicensed spectrum as well as stand-alone operation. For the purpose of simplicity, I am collapsing these scenarios into two main modes of operation:
- Licensed assisted access NR-U
- Stand-alone NR-U
I am very pleased to see NR-U being included in the next 3GPP release, since I see it is as the fruit of all the pioneering work that Qualcomm Technologies started more than five years ago with LTE-U and later with LTE LAA and LTE based MulteFire.
Licensed assisted access NR-U (LAA NR-U)
The first mode, LAA NR-U, extends the success of LTE-U/LAA from 4G LTE to 5G NR. This mode enables operators to boost the network performance — both speed and capacity — by aggregating unlicensed spectrum with licensed spectrum. LAA NR-U will support both NR and LTE in licensed spectrum (the anchor I mentioned before) combined with NR-U in unlicensed spectrum. It can be deployed either by using carrier aggregation in a small-cell supporting both licensed and unlicensed spectrum or by dual-connectivity between a macro-cell using licensed spectrum and a local small-cell using unlicensed spectrum. An operator’s spectrum strategy includes leveraging all types of spectrum, so I am certain that LAA NR-U will provide a powerful tool for 5G operators, similar to how they use LAA today to offer Gigabit LTE in more places.
The second mode, stand-alone NR-U, is an equally exciting evolution of 5G. In some way it may be more intriguing or even fundamental, since it marks the expansion of cellular technologies standardized by 3GPP into stand-alone operation in unlicensed spectrum (i.e. without an anchor in licensed spectrum) As I mentioned, licensed spectrum is the cornerstone for ubiquitous mobile communication, but the ability to operate 5G NR stand-alone in unlicensed spectrum is a basic technology enabler that will be exploited by future use cases, surely more than the ones we can think about right now. This is not about creating a better Wi-Fi, but about serving unmet needs to expand the market for wireless communication to new verticals such as:
- Local private 5G networks dedicated for a specific application such as industrial IoT or mobile broadband for enterprises. My colleague just held a webinar explaining some of the business opportunities using private 5G networks that I recommend if you want to learn more.
- Open mobile broadband 5G services offered by new service providers such as today’s cable operators and internet service providers or neutral host service providers in public venues such as sports stadiums and malls.
- More use cases that will be conceived in the future.
The vision for stand-alone cellular operation in unlicensed spectrum started with a concept called MulteFire, which extended the capability of LTE to operate in unlicensed spectrum that was created by LTE-U/LAA. This work was carried out by the MulteFire Alliance—to standardize a solution aligned with 3GPP and build an ecosystem. This is now bearing fruit as now 3GPP itself is adding this functionality to 5G NR. With stand-alone NR-U now becoming part of the 3GPP standard, we believe that the broader market interception for stand-alone cellular operation in unlicensed spectrum will occur with 5G.
Making NR-U a reality
I look forward to holding my first mobile 5G smartphone. I am also eager to experience all the new functionalities in the next 3GPP release, specifically about NR-U, that will expand 5G to new verticals. As I am writing this on the way back from the 3GPP plenary in Sorrento, Italy, my colleagues at Qualcomm Technologies are hard at work adding NR-U to our 5G testbeds — we look forward to sharing results next year. 3GPP release 16, which includes NR-U, will be finalized at the end of 2019, meaning that before too long we can look forward to seeing NR-U deployed around the world.