Shulou(Shulou.com)11/24 Report--

In early June 2022, the 96th plenary session of the Communications Standards Organization (3GPP) was held in Budapest, Hungary as scheduled.

At this meeting, the high-profile 3GPP R17 standard was officially frozen. This indicates that the first stage of the evolution of 5G has been completed, and the development of 5G technology will enter a new second stage.

In retrospect, about seven years ago, in September 2015, ITU ITU officially confirmed the three major application scenarios of 5G (eMBB, mMTC and uRLLC). Soon after, in March 2016, 3GPP officially launched the standardization of 5G, which aims to develop a unified and more powerful wireless air port-5G NR (New Radio).

Now, as time flies, we have witnessed the freeze of 3GPP R15, R16 and R17 versions, as well as the full commercial and landing popularity of 5G.

5G, which is highly expected, has experienced the development process from birth to maturity, is constantly changing our work and life, but also subverts the operation mode of the whole society.

So the question is, what revolutionary technological innovations have emerged in the continuous evolution of 5G? What kind of logic is hidden behind these technological innovations? What is the role of each stage from R15 to R17?

In today's article, Xiao Zaojun will lead you to find the answer.

R15: lay the foundation and unveil. First of all, let's take a look at R15's innovative ideas.

R15 is the beginning of the development of 5G standard. As the saying goes, "A good beginning is half success." In order to take a solid first step, experts in the communications industry have carried out adequate research and preparatory work.

At that time, the most important mission of R15 was to develop standards for eMBB (enhanced Mobile Broadband) scenarios. In this scenario, what is needed is the most important indicator of the communication network-speed.

For eMBB, ITU requires that the peak downlink speed must be above 10Gbps, and the user experience rate must be above 1Gbps. In order to achieve this requirement, 3GPP adopts two ideas: one is to find more available spectrum resources, and the other is to tap the potential of each MHz frequency resources.

In the aspect of expanding spectrum resources, 3GPP proposed mobile millimeter wave technology on the basis of Sub-6GHz band. In other words, the working spectrum of 5G is extended to a higher frequency band, covering the millimeter wave band.

The speed and capacity increase brought by mobile millimeter wave is very obvious, which lays the foundation for 5G high-speed connection.

On the basis of millimeter wave technology, 3GPP introduces Massive MIMO (large scale Antenna Array).

This technology is one of 5G's most iconic innovations and can be said to be a "masterstroke". It greatly increases the number of antennas in the base station, thus forming independent narrow beam coverage for different users, thus increasing the system throughput tens of times, and also improving the coverage effect of the base station (especially to make up for the lack of millimeter wave coverage).

▲ Massive MIMO

In terms of tapping the potential of spectrum resources, the technical challenge is even greater. This involves a large number of underlying technological innovations, including multiple access technology, modulation technology, coding technology, physical layer structure and so on, which need to be redesigned.

One of the most important decisions in the design of 5G NR is to choose wireless waveform and multiple access technology.

During the scheme evaluation process at that time, Qualcomm found through extensive research that the orthogonal frequency division multiplexing (OFDM) system, including cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) and discrete Fourier transform spread spectrum orthogonal frequency division multiplexing (DFT-S OFDM), was the best choice for 5G eMBB and more other scenarios.

Based on the existing OFDM applications of 4G LTE, Ji Tingfang, Senior Engineering Director of Qualcomm, designed a unified sub-carrier spacing exponential expansion formula to achieve scalable OFDM parameter configuration. This technical invention, known as the "Extensible Parameter set", is a major highlight of R15.

By using the scalable OFDM parameter configuration, the subcarrier spacing can be extended to the nth power of 2 with the channel width. In this way, in systems with larger bandwidth, the size of FFT points also expands without increasing the complexity of processing.

Another refreshing design of R15 is a flexible framework based on time slots. The key technical invention of the flexible framework is the self-contained time slot structure of 5G NR. In the new self-contained time slot structure, each 5G NR transmission is modular and has the ability of independent decoding, which avoids the static timing relationship across time slots.

In June 2018, the 3GPP R15 standard was officially frozen. Now it seems that R15 successfully fired the first shot of the 5G. Many innovations it brings unveil the mystery of 5G and lay a solid foundation for the subsequent iterative evolution of 5G.

R16: scenario expansion, enabling industry R15 mainly sets standards for eMBB (enhanced Mobile Broadband) scenarios. On the basis of R15, R16 further improves the standard specifications of uRLLC and mMTC scenarios, thus contributing to the first 5G complete standard and the first 5G evolution standard.

In essence, to support and empower the vertical industry is the most important mission of R16.

R16 needs a standardized uRLLC (Ultra reliable low delay Communication) scenario, which is mainly aimed at vertical industries such as industrial Internet and vehicle networking. ITU's metrics for uRLLC scenarios include more stringent reliability requirements (up to 99.9999%) and millisecond latency.

R16 needs to further enhance the basic capabilities of the 5G network and introduce more new network features, so as to better support the key business use cases of toB and meet the needs of vertical industries such as intelligent manufacturing, intelligent quality inspection, self-driving and so on.

In terms of the enhancement of the basic capability of the network, R16 has made special optimization and enhancement in the aspects of spectrum efficiency, network utilization and robustness, including large-scale antenna enhancement, carrier aggregation enhancement, handover technology enhancement and so on. the availability and perfection of 5G are greatly improved.

In terms of the introduction of new features, the performance of R16 is even more remarkable.

Taking spectrum expansion as an example, R16 has added support for 5G NR Free Spectrum (NR-U), including two modes: licensed Auxiliary access (LAA), and independent deployment of spectrum without any license. This not only leads to greater capacity, but also enables more flexible deployment.

For the reliability and delay requirements mentioned above, the multipoint cooperative communication (CoMP) dominated by Qualcomm is one of the key enabling technologies to achieve this goal. In this technological innovation, by using multiple transmitting and receiving points (multi-TRP), spatial diversity with redundant communication paths is created to achieve high reliability and low delay, and an available time-sensitive network (TSN) is built.

Vehicle networking (V2X) is an important vertical application field of 5G. In this field, direct connected communication (D2D), mainly promoted by Qualcomm and other companies, is an important technological innovation, which can realize V2X to support vehicle formation, semi-autonomous driving, epitaxial sensors, remote driving and other richer vehicle networking applications.

▲ vehicle networking (V2X)

R16 introduces remote interference management, wireless relay, network organization and self-optimization technology in networking technology, which improves the actual user experience of the network.

Typical examples are new interference measurement and suppression technologies (such as RIM / CLI) and integrated access and backhaul (IAB).

Integrated access and backhaul (IAB) supports millimeter wave base stations for wireless access and backhaul, which can effectively reduce the need for new optical fiber deployment when deploying dense networks.

It is particularly worth mentioning that in order to better promote the landing of 5G in the government-enterprise vertical industry, R16 has also made innovations in the private network deployment mode and launched support for non-public networks (NPN), pointing out the direction for the development of 5G private network communications.

R16 introduces many new features, including terminal energy saving, terminal mobility enhancement, high-precision positioning and so on.

In July 2020, the R16 standard was officially frozen.

If R15 only implements a "available" 5G, then the role of R16 is to turn the "available" 5G into the "easy to use" 5G. It has been deeply enhanced and improved in terms of cost, efficiency and function, paving the way for the full landing of 5G.

R17: ability upgrade, application exploration has finally reached R17!

If one word is used to describe the positioning of R17, it is "connecting the past with the future".

As the third major version of the global 5G NR standard, R17 further extends the basis of 5G technology in terms of network coverage, mobility, power consumption and reliability, expanding 5G to new use cases, deployment methods and network topologies.

The keywords of R17 evolution can be divided into "enhancement" and "extension".

Network basic capability Enhancement R17 is a standard developed after commercial use on a 5G scale. Therefore, it can carry out "leak checking and filling gaps" based on the experience of the actual deployment of 5G and the deficiencies found.

R17 brings more enhancements to the capacity, coverage, delay, energy efficiency and mobility of 5G systems, including Massive MIMO enhancement, coverage enhancement, terminal power saving, spectrum expansion, IAB enhancement, uRLLC enhancement and so on.

Let's start with the spectrum.

R17 spread the spectrum of 5G millimeter waves, defining a new unique frequency range called FR2-2, pushing the upper limit of the millimeter wave spectrum to 71 GHz.

This means that the network capacity of 5G millimeter wave will become larger, and more use cases and deployment methods will be realized. For example, the millimeter wave enterprise private network which supports communication and location functions in the intelligent manufacturing industry.

Thanks to the 5G NR Extensible subcarrier spacing (SCS) scheme and the flexible slot-based frame structure, this band extension extends the subcarrier spacing of control and data channels directly to 480 kHz and 960 kHz (previously 120 kHz in low-band millimeter waves).

In addition to band expansion, R17 brings other millimeter wave enhancement features, including support for inter-band uplink / downlink carrier aggregation and enhanced mobility.

IAB (Integrated access and backhaul) enhancements, which come from features such as simultaneous transmit / receive (full duplex) and enhanced multihop operation, can further improve deployment efficiency, coverage, and performance. This is especially useful for millimeter wave deployments, which can quickly expand coverage more cost-effectively and efficiently.

In terms of terminal capability enhancement, R17 has proposed a series of enhanced features in order to improve the user experience.

For example, support for up to eight antennas and additional spatial streams for higher throughput; advanced MIMO enhancements to increase capacity, throughput and battery life; new energy-saving features for connected and idle modes to extend battery life; retransmission and higher transmission power to improve terminal network coverage; and enhanced 5G positioning technology to improve positioning accuracy and delay Dual card dual standby, which can support the concurrency of two ordering services of single or two operators; and so on.

As the transition of the first and second stages of 5G, 5G network and terminal application extension R17 should not only enhance the existing 5G, but also explore more application possibilities of 5G scenarios. These possibilities include RedCap, non-terrestrial network (NTN), extended direct connection communication, centimeter level positioning, extended broadcast / multicast, and unbounded XR (extended reality).

The most representative technology introduced by 5G R17 is, of course, RedCap for low and medium speed Internet of things applications, that is, NR-Light.

RedCap is a simplified version of 5G, which can meet the needs of the Internet of things such as wearable devices, industrial sensors and surveillance cameras by reducing the complexity of the protocol and adopting better energy-saving technology.

Another noteworthy new feature of R17 is non-terrestrial network (NTN).

In recent years, people pay more and more attention to satellite communication. In order to enable 5G to provide ubiquitous connectivity, 3GPP has also strengthened its research on non-land area network coverage. In R17, there are two parallel NTN working groups to address mobile broadband and low-complexity Internet of things (IoT) use cases.

The first project uses the 5G NR framework for satellite communications, implements ground-to-satellite fixed wireless access (FWA) backhaul, and directly provides low-rate data and voice services for smartphones. The second project focuses on supporting satellite access to low-complexity eMTC and NB-IoT terminals, expanding network coverage for key use cases, such as global asset tracking.

The last new direction I would like to mention in R17 is unbounded XR.

Meta-universe, which exploded last year, shows us a personalized digital experience that spans both physical and virtual worlds. As the underlying supporting technology of meta-universe, XR extended reality technology, represented by VR and AR, has received more attention.

The XR project in R17 focuses on studying and defining various types of XR traffic (AR, VR, cloud games). This study defines requirements and assessment methods for identified XR traffic types and supports performance assessments to determine future areas of improvement.

In conclusion, someone once said that the development of 5G from R15 to R17 is like a process of building a house:

R15 version is the "rough room" of 5G technical standard, which sets up the foundation and framework. The R16 version is the "fine decoration" of the 5G standard, so that it has the preliminary "living conditions". The newly released R17 version is a "soft outfit" on top of "hardcover", which has the effect of icing on the cake and makes the living experience better.

It is true. The first stage of 5G is a process of dynamic expansion, and mobile communication technology begins to empower the industry Internet and digital intelligence change.

Through the technological innovation mentioned above, we are constantly challenging the limit of Shannon theory and groping for the future development direction of communication technology.

Judging from the current phased achievements, 5G has laid a connecting foundation for the digital transformation of the whole society through these very subversive scientific and technological innovations. A large number of 5G vertical industry landing cases have greatly enhanced people's confidence in 5G and the digital economy.

Looking to the future, we are about to enter the 5G-Advanced era. The first standard version of 5G Advanced, R18, has been fully launched. It will start a new round of wireless technology innovation and protect the prosperity and development of the digital economy.

What kind of splendor is waiting for us? Let's wait and see!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.