[Tech Day 2022] Hyper-Connected: The Road to 6G Era

In his keynote speech at this year’s Tech Day, Jungwon Lee, Executive Vice President, Head of Modem Development Team, outlined the evolution of connectivity technologies – from the initial deployment of 5G technology to the emerging era of 6G cellular connectivity. Lee also speaks about the history of Wi-Fi technology and the performance capabilities that the next generation of Wi-Fi – Wi-Fi 7 – will require. Connectivity Technologies for 5G and 6G EraThe initial deployment of 5G 5G’s initial deployment required two stages and was spearheaded by the 3rd Generation Partnership Project (3GPP). Each stage involved radio technology specification development -- non-standalone architecture followed by standalone architecture in June 2018. Once ready for commercial deployment in August 2018, Samsung developed the industry’s first 5G NR-compliant modem, the Exynos Modem 5100, to power Samsung’s first 5G smartphone -- the Galaxy S10 5G. The introduction of 5G transformed the industry. Unlike LTE, Lee says, “5G makes use of scalable orthogonal frequency-division multiplexing (OFDM) technology that supports both sub-6 gigahertz and mmWave.” This meant the technology could handle larger frequency bands than what was possible at the time with LTE. Additionally, the shorter OFDM symbols enabled low latency, and the use of the new mmWave spectrum dramatically increased throughput. As an added benefit, Lee highlights the impact 5G had on performance. He says, “5G technologies have improved performance greatly with new channel coding systems, such as low-density parity-check code (LDPC) and polar codes.” The Emergence of 6G Technologies 6G-enabled technologies are coming, and Lee highlights several important aspects that will drive its development.

Just as 5G technology enabled higher bands, leading to the introduction of the mmWave spectrum, 6G will leverage even more spectrum, antennas, and frequencies. In fact, Lee says it is “expected to use the terahertz band in the range of 100 gigahertz to 10 terahertz.” This comes with both advantages and challenges. For example, the main benefit of terahertz technology is an abundance of bandwidth and compact antenna arrays; however, the main obstacles to its roll out are radio-frequency integrated circuits (RFIC), transceiver design, and coverage.

In addition to the terahertz frequencies, Lee says, “an upper mid-band consisting of frequencies from 7 to 24 gigahertz could serve as an important anchor for coverage in 6G.” However, an upper mid-band would still require enhanced technology to maintain coverage comparable to sub-6 gigahertz technology. Challenges to 6G coverage at the higher end of the spectrum are pushing further development of advanced antennas, and Lee believes this will feature three key elements: large intelligent surfaces, line-of-sight (LOS) multiple-input multiple-output (MIMO), and ultra-massive MIMO. Large intelligent surfaces use programmable meta-surfaces to create favorable channel environments. LOS MIMO achieves spatial multiplexing even in the line-of-sight scenario, while ultra-massive MIMO extends its capabilities from the gNB side to the device side. This will require smaller antennas to pick up smaller wavelengths at higher frequencies, such as those in the terahertz range.

Furthermore, increasing efficiency will demand a full duplex communications system. As we saw with 5G technologies, 5G-Advanced has already started this process. However, as Lee points out, “true full duplex — including user equipment — will only be realized with 6G.” For modulation design, the main goal is to design a modulation constellation that considers severe impairments in analog circuits, such as high phase noise. With the potential of full-digital MIMO and a low-resolution analog-to-digital converter (ADC) and digital-to-analog converter (DAC), the industry must advance baseband signal processing to optimize modulation design. Another important aspect of 6G is energy efficiency. Lee underscores the fact that the industry will “need to consider near-zero-energy communications and energy harvesting” to maximize the potential of 6G. To do this, AI will be a key ingredient. AI is already integral in 5G-Advanced for purposes such as channel state information (CSI), beam management, and positioning. “However, unlike 5G, AI will be considered as a native technology for the 6G physical layer (PHY), and it will be used to design a communication system over all layers,” says Lee. Using AI in the Physical Layer As an overview, Lee explains that AI can be used in the 6G physical layer to build intelligent modems, and this happens at three levels:

• The control level: AI can control various parameters of conventional signal-processing algorithms.
• The block level: AI can replace some of the processing blocks in the system, such as channel coding, channel estimation, symbol detection, beamforming, and CSI.
• The system level: AI can be used to build the whole communication system.

Samsung Exynos Modem Innovations in the 5G Era With a strong commitment to the development of technology, Lee says, “Samsung System LSI has been at the forefront of cellular modem innovations — all the way from its first LTE modem to the industry’s very first 5G multi-mode modem.” Since the release of our first 5G modem in 2018, Exynos baseband and RF modem solutions have been commercialized for all smartphone segments. This year, we released the flagship Exynos 2200 and Exynos modem 5300, which are 3GPP Release 16-compliant. Moving forward, Lee says, “while we continue to advance our 5G modems further, we’re also innovating cellular modem technology for the 6G era.” The Road to Wi-Fi 7 and BeyondWi-Fi History from 1 to 6E Wi-Fi has evolved to accommodate higher speed and expanded coverage. Starting as a single carrier system with Wi-Fi 1, Wi-Fi 2, 3, and 4 evolved to adopt OFDM and MIMO techniques. Lee explains that Wi-Fi 5 took it a step further “by featuring a multi-user MIMO technique that allowed a single access point to transmit data to multiple devices simultaneously.” Wi-Fi 6 introduced orthogonal frequency-division multiple access (OFDMA), which allowed networks to deliver superior performance even when multiple devices are connected at once. The first iteration of Wi-Fi 6 could only be used at 2.4 and 5 gigahertz, but Wi-Fi 6E changed that, enabling use in the 6-gigahertz band. Wi-Fi 7 and Beyond Wi-Fi 7 is the next evolution of Wi-Fi, and it will be what enables new technologies like 4K and 8K video, virtual reality (VR) and augmented reality (AR). To meet the heightened demands of these technologies, Lee says, “Wi-Fi 7 makes it possible to transmit data as fast as 23 gigabits per second, with 4k-QAM and 320-megahertz bandwidth.”

Wi-Fi 7 builds on the abilities of Wi-Fi 6, which allows users to send and receive frames only from an allocated resource unit. With Wi-Fi 7, each user can use multiple resource units, which Lee says, “gives us more options and speeds up transmissions.” With the new multilink operation in Wi-Fi 7, data can be sent and received simultaneously across various bands and channels. As the industry looks to the future, the Institute of Electrical and Electronics Engineers (IEEE) launched the Ultra-High Reliability (UHR) study group, whose main objectives include:

• Improve reliability
• Reduce latency
• Increase manageability
• Increase throughput at different SNR levels
• Reduce device-level power consumption

The UHR study group is already considering multi-AP coordination, virtual basic service set, and two-dimensional physical-layer protocol data units as candidate technologies for further study. Samsung’s Connectivity Tech Today Samsung’s Wi-Fi and Bluetooth modems power devices all over the globe. Since 2016, we have supplied the market with more than 400 million chips, and that number continues to grow. Our product line is expanding beyond smartphones and tablets to include wearables, and it will soon include an even more diverse range of devices. In referencing the next generation of connectivity, Lee says, “we’re continuing to stretch beyond what was possible and change the world of wireless communication. As the world’s technologies evolve, we are evolving not just with them, but ahead of them.”