The second version of the 5G specification, "Rel-16", is here. What changes does it bring?

When it comes to 5G technology, we have always paid more attention to the progress in terminals, such as which company has launched a new 5G mobile phone, and which chip supports 5G networks quickly and well, but we rarely pay attention to the evolution of 5G technology itself.

5G NR (New Radio) is a global 5G standard based on OFDM's new air interface design. On June 14, 2018, the International Telecommunication Standards Organization 3GPP announced on its official website that after 34 months of hard work, it has completed the fifth-generation mobile communication specification of Standalone (SA) Release 15, also known as Rel-15.

Rel-15 can be regarded as the first completed 5G standard, which includes the previously completed NSA and newly completed SA standard specifications. These are the standard specifications that we saw implemented last year. Now the new 5G mobile phones have completed dual-mode 5G network support, but the evolution of 5G standards has not stopped.

The next version after Rel-15 is naturally Rel-16. In the original initial plan, the development time of Rel-16 was to be completed in December 2019 and then frozen in March 2020. However, because Rel-16 itself supports more technical branches, the Rel-16 time plan was postponed at the 82nd 3GPP meeting in December 2018. The original plan was to freeze Rel-16 in June 2020.

Dr. Xu Hao of Qualcomm said that due to the impact of the current global epidemic, the freezing time of the Rel-16 standard has been postponed for 3 months to September. It can basically be considered an overall postponement of three months. However, we are still working hard to complete the second phase of Rel-16 work and strive to complete the Rel-16 standard in June.

So, what key technologies and features will be included in the second version of the 5G standard?

According to Dr. Xu Hao of Qualcomm, we can simply divide the improvements of Rel-16 into new technology improvements and new function implementation. The former mainly serves the foundation and deployment of 5G, while the latter can realize more new functions that users can perceive.

The first point can be seen as a continuation of the Rel-15 version, which is to continue to enhance the communication capabilities of sub-6GHz and millimeter wave technologies. New technologies in this area include integrated access backhaul nodes, more standard designs for mobile phone energy saving, and new unlicensed spectrum designs. In addition, Rel-16 also enhances mobility, with the goal of achieving 5G zero-second handover between cells, etc.

The new technologies brought by Rel-16 can also expand more functional implementations, such as providing a new 5G positioning function, which can calculate the distance based on the round-trip time of the base station signal, and then calculate through the changes in the angles of signal arrival and emission. Currently, in 80% of cases, it can achieve a positioning accuracy of 3-10 meters. This function is expected to reach the sub-meter level (within 0.3 meters) in the next version Rel-17.

Compared with the current GPS positioning, 5G positioning technology can support indoor positioning and can be used as a supplement to different positioning technologies. In addition, the high precision and low latency characteristics can meet different positioning needs. In addition, it also brings enhancements to the industrial Internet of Things and 5G broadcasting.

So what scenarios can these enhanced features help to achieve? Qualcomm gave an example of XR applications. For example, users can use an XR glasses to view objects in 3D, and then perform some real-time operations such as changing colors.

This is a simple XR application scenario, but it is not easy to actually implement this scenario. For example, due to the size of XR glasses, the battery life and computing power will be greatly limited. On the one hand, the chips, process technology, integration, design and other aspects must be optimized, and on the other hand, the calculations need to be distributed, that is, part of the rendering calculation process is put on the edge cloud for processing.

Simply put, it needs to rely on cloud computing. XR glasses are only responsible for processing the most important data locally, and the rest is assisted by cloud computing. However, if you want the entire usage process to be nearly seamless, the cloud computing part has to be almost the same as local computing. This puts forward requirements for low latency and connection reliability between the cloud and the terminal. This will use 5G's ultra-low latency technology on the air interface, as well as edge cloud computing and separate rendering technologies to finally realize this scenario.

What involves more general users is the practicality of millimeter waves. We know that China is currently using the Sub-6G spectrum, and the millimeter wave band has only been approved for licensing but has not yet been actually deployed and covered.

However, in many countries, due to various reasons, millimeter waves are first deployed on a large scale. At present, due to some disadvantages of millimeter waves in their own physical characteristics, the strategy currently adopted by millimeter waves is hotspot coverage, such as concert halls, conference rooms, airports, train stations, etc.

However, the evolving millimeter wave technology can not only be used for hotspot coverage to serve smartphones, but can also introduce some new services and usage scenarios. For example, using drones to shuttle around a campus, Qualcomm has achieved stable connection of terminals when moving at high speeds and at high altitudes. At the same time, switching between millimeter wave base stations is now smoother and seamless.

Further down the line, there are industrial IoT and enterprise private networks for vertical fields, such as factories or docks. Enterprise private networks can monitor logistics conditions in real time. In addition, some countries, such as Germany, have prepared unlicensed 5G spectrum resources for industrial IoT, and the deployment is also quite flexible and simple. Enterprises can choose to build their own private networks or use 5G network slicing to build private networks according to their needs.

As manufacturing technology develops, new technologies such as robotic arms, XR, and a large number of sensors will gradually be applied in future production workshops. What drives these new technologies to work together is the application of 5G in the industrial Internet of Things.

Finally, there are new features about 5G cellular vehicle-to-everything (C-V2X) technology. In Rel-16, the newly added reliable multicast communication based on distance groups and sensor sharing brings many advantages. In Qualcomm's demonstration scenario, when a C-V2X-enabled car approaches an intersection, it will automatically form a group communication. It can not only communicate with surrounding C-V2X-enabled cars, but also sense the speed of cars that do not have C-V2X features, and share it with surrounding C-V2X-enabled cars for reminders.

The 5G NR specification is also divided into three major scenarios for different 5G needs. 5G eMBB and URLLC are aimed at smartphones, high-end industrial Internet of Things, and XR needs. 5G NR-Light is aimed at high-end wearable devices, smart grids, high-end logistics tracking, and health status monitoring. 5G IoT is aimed at smart cities, low-end industrial Internet of Things applications and other needs.

After Rel-16, the next version, Rel-17, is also being prepared and will implement more features, such as support for massive IoT needs. The Rel-17 specification is expected to be developed between 2020 and 2021, and the standard will be frozen as early as September 2021.

After the specifications for smartphones were gradually improved, 5G began to deploy a more ambitious layout in smart cities and Internet of Vehicles. Of course, in terms of implementation speed, the construction time of a smart city is much longer than the time to build a 5G mobile phone, but 5G has already painted a fairly close picture of a future city for us.