[All About Exynos] ③ A Deeper Look at Modem, Connectivity and Security in Telecommunication

Supporting Fast, Smooth Telecommunication Anywhere: The Ultra-High Performing Modem with AI Technology

The term “modem” encompasses all types, from the dial-up modems used in the 1990s to connect PCs to the Internet, to wired communication modems like digital subscriber line (DSL) and cable, to wireless communication modems for cellular service and Wi-Fi. However, when we talk about modems today in the mobile industry, the term usually refers to cellular modems for wireless communication that support LTE and 5G.

In a smartphone, the terminal modem is in charge of making calls and transmitting and receiving data by exchanging signals with base stations. The reason we can make calls and seamlessly watch videos anywhere is all thanks to high-performing cellular modems. Today, the latest cellular modems support technologies from 2G to 5G. 

Cellular modems were first used for 1G when only phone calls could be made using the analog communication method. In the 2G era, the digital communication method¹ was introduced, and additional services such as the short message service (SMS) became possible. 3G enabled the use of the Internet on mobile phones, laying the foundation for mobile broadband,² and 4G ushered in the true mobile broadband era that made seamlessly watching HD videos possible. The speed of 5G, which Korea was first in the world to commercialize in 2019, now reaches the 10Gbps level, and various applications other than mobile devices are being created using this low-latency and hyper-connectivity technology. 

▲ A comparison of the characteristics of different mobile communication generations.

With the advent of the LTE era, data transmission speeds have become remarkably higher, and mobile phones can now provide functions almost identical to those provided by computers. Having experimented with developing its own modem before the 2000s, Samsung Electronics began developing an LTE modem chip in earnest in 2007 and became the first in the world to succeed in LTE modem commercialization in 2009, after mastering 2G and 3G technologies.

▲ The communication process between a modem and a base station.

In 2012, the Galaxy S series was equipped with Samsung’s LTE modems for the first time. In 2019, the 5G-integrated SoC Exynos, the first ever chip to combine a 5G communication modem and a mobile AP, was developed. Exynos improved energy efficiency by combining two chips with different functions into one as well as the ease of design for smartphone manufacturers by reducing the area taken up by the component. Currently, Exynos’ 5G³ modem supports not only the sub-6GHz band but also extremely high frequency bands (i.e., mmWave), such as 28GHz and 39GHz. Thanks to this, sub-6GHz increases service coverage, and ultra-high-speed communication is offered with mmWave near base stations. 

Today, Samsung is one of the world’s top three 5G modem design companies. “Generally, the process for developing a modem is complicated because it must support new technology like 5G and already commercialized technologies like 3G and LTE. As it also requires a significant investment, there are only a handful of modem chip companies in the world,” said Vice President Jungwon Lee, a signal processing expert who currently leads the Modem Development Team in the System LSI Business after working at Samsung DS America and at Samsung Research America. “It is an area that also requires a lot of development time, from algorithm development to chip design, software development and field testing.”

▲ Vice President Jungwon Lee (right) and PL Huiwon Je (left) of the Modem Development Team strive to improve the development performance of cellular modems.

Samsung is conducting field tests in countries around the world to improve service coverage as much as possible and making various efforts to improve the baseband signal processing method, including the use of artificial intelligence (AI) technology to increase transmission speeds. As a result, the company successfully created a modem that utilizes AI algorithms last year, although it is yet to be commercialized. “Modems with AI technology can promote performance enhancements by minimizing the processing of interference signals or increasing energy efficiency through the use of AI processors,” said Lee.

In addition to 5G, Samsung is currently actively working on the development of 6G technology. “Right now, we are focused on developing the world’s best 5G modem and 5G-Advanced modem, and we are preparing for 6G modem technology research in collaboration with Samsung DS America and Samsung Research for the imminent 6G era,” said Lee. His achievements in modem signal processing technology were recognized when he was selected as a Fellow of the IEEE.⁴

“6G modems are expected to enable 1Tbps-level speeds, support various communication networks including satellite communication, and be widely used in various applications, such as automobiles, IoT and AR/VR — going far beyond smartphones,” he said. “To pave the way for the 6G era, we must have the backing and support of various frequency bands, including the terahertz (THz) band, multi-antenna support for at least hundreds of antennas, advanced AI technology and communication network signal efficiency technology.”

Meanwhile, Lee is leading the way for Samsung as the company aims to create the best modem for Android. “We are expanding our 5G business in the short run while striving to secure a leading position early on in the 6G era in the medium to long-term,” he said. Samsung plans to drastically increase the headcount of the Modem Development Team to improve such performance and to expand related business markets. 

“I am proud to be a part of the development team of a major global company that leads modem technology. On a more personal note, I find it fascinating to see how what I learned from theories can actually be implemented in many cases when applied to products,” said Lee when asked why he was so drawn to modems. “Today, having seamless telephone conversations anytime and anywhere and the high-speed internet experience have become a fundamental part of life. The thing that has allowed us to experience this convenient life is modems, and the Modem Development Team is enthusiastic about continuing to play its role in these developments.”

Making an Extensive Connectivity Environment That Works Quickly and Fluidly

The two main telecommunication standards for mobile wireless communications are cellular networks and connectivity. The cellular network represented by the 3GPP standard⁵ refers to telecommunication standards such as CDMA, LTE and 5G. It provides a wide range of service coverages in certain bandwidths licensed for mobile carriers and does this via the infrastructure of various base stations. Connectivity, on the other hand, is represented by IEEE 802.11(Wi-Fi)/802.15 (Bluetooth, ZigBee, UWB⁶). It utilizes Industry-Science-Medical (ISM) bandwidth that can be used by anyone. Connectivity follows local telecommunication standards for indoors and provides service to all.

▲ The types of Wi-Fi protocols for wireless connection

“Cellular network” is a service with an infrastructure based on mobility and is mainly operated by establishing networks that cover wide areas. On the other hand, “connectivity” provides wireless access among devices within a short distance without using infra-networks established by operators. This allows for the convenience of portability without wires. In particular, Wi-Fi boasts a faster transmission speed more reliably than cellular networks over relatively long distances, especially indoors. This is why Wi-Fi is so widely used for connecting mobile phones, laptops and so on. Just like peer-to-peer (P2P), Wi-Fi is better for selective and intensive telecommunication that can, when necessary, facilitate high transmission speeds. This makes it more appropriate for next-generation IoT devices, such as Augmented Reality (AR) and Virtual Reality (VR) devices.

These days, it is hard to even imagine daily life without Wi-Fi. It is easy to forget that, just 20 years ago, Wi-Fi was not expected to become the most commonplace wireless data telecommunications technology. However, as the industry expanded to smartphone-based technology, the realization grew that Wi-Fi was the most effective method of response to today’s data traffic explosion. Thanks to the lower cost of setting up and operating — when compared to cellular networks — it is a method that is still growing exponentially.

Unlike cellular systems using infra-networks, the data link range of a Wi-Fi network can only be extended up to a few hundred meters, so it is emphatically local. In addition, as it uses unlicensed bandwidth, it can be affected by interference from other telecommunication systems, making it risky for supporting advanced Quality of Service (QoS).⁷ However, as cellular and Wi-Fi convergence technology advances, it continues to provide a huge convenience: an undisrupted user experience. All over the world, Wi-Fi has long gone beyond being seen as a specific technology and is instead treated more like a public infrastructure.

“Back in 2016, a dedicated team was set up to get Wi-Fi technology to the point where it could be integrated into the Exynos processor,” said Joonsuk Kim, Executive Vice President of the Connectivity Development Team. Kim was the team leader when the Connectivity Team was first established when joining Samsung in 2016. “In only about four to five years, we completed the development of the legacy protocols all the way up to the sixth generation of Wi-Fi (Wi-Fi 6) by achieving technological stability and readiness. Although there was not enough investment or talent, our technology caught up in just a short period of time,” he recalled.

▲ Exynos’ Wi-Fi technology nearing the market leader in only six years

After its success in developing and commercializing Wi-Fi 6E, as well as all the previous Wi-Fi protocols, Samsung Electronics is now developing Wi-Fi 7, which is targeted for next generation flagship as a discrete modem. Since Wi-Fi needs to provide connection for all mobile and IoT devices supporting the latest protocol, it is crucial that the performance of all legacy protocols is improved and maintained and that the performance of the most recent protocol is similarly secured. This latest protocol — Wi-Fi 7 — will likely be expanded to the market from 2024. It boasts the Multi-Link Operation (MLO),⁸ a channel bandwidth of 320MHz and 4096QAM.⁹ Through these capabilities, Wi-Fi 7 will have the advantages of faster data transmission speed, increased data transmission volume, improved power efficiency and the ability to support undisrupted wireless connectivity, even in an environment where users abound.

▲ The size of the Wi-Fi market is projected to grow from 4.7 billion in 2022 to 6 billion in 2027.
Source: LANCOM (Survey Digital Policy in Germany), TSR (June 2022)

In order to further enhance the fast transmission speeds of Wi-Fi, the internal processor core needs to become more complex than it currently is, and an internal memory with a large capacity is required.

“To make this happen, we are staying focused on research and development of multi-processor structures, and on securing the intellectual properties necessary for fast transmission,” Kim said. “Until now, companies in other countries have been the main players leading the development of Wi-Fi solutions. But the Wi-Fi technology of Exynos is the only Wi-Fi solution in Korea that is commercialized on a large scale. I’m confident that, when it comes to embedded Wi-Fi solutions for mobile SoC, our technology comes second to none,” Kim said.

This is important, because, when it comes to Wi-Fi, only the best is good enough for customers. Although most people, in general, do not realize how much of an advanced technology Wi-Fi truly is, they do expect to be able to access fast, uninterrupted Wi-Fi almost wherever they are.

“Many users recognize revolutions in cellular networks, such as the LTE and 5G, as advanced technologies, thanks to their advertisement as major features of phones in mobile carriers’ active marketing,” said Kim. “However, by contrast, people do not quite seem to recognize how quickly Wi-Fi technology is evolving.”

▲EVP Joonsuk Kim has been working on connectivity technology for 20 years.

However, when asked if he thinks the role of Wi-Fi will still be important in the future, Kim was resolute.

“The data transmitted through Wi-Fi these days makes up 70 to 80%¹⁰ of overall wireless data traffic,” he said. “Cellular networks and connectivity technology pursue different usage scenarios and this is not likely to change any time soon. Wi-Fi technology and cellular technology should advance together by complementing each other. As the role of information technology (IT) becomes more important in our lives, the ability to minimize dead-zones and provide stable connections and fast data services indoors will become very important for Wi-Fi technology.”

To fully tap into future technologies like augmented reality (AR), virtual reality (VR) and the metaverse, fast speed and low latency are crucial.

“Wi-Fi uses low-frequency bandwidth, such as 2.4GHz, 5GHz and 6GHz,” Kim explained. “So the diffraction is relatively higher, and this enables the fast, stable transmission of data.”

As 320MHz frequency became usable with the availability of 6GHz bandwidth, connections between devices with ultra-fast and low-latency could be achieved even faster than originally expected. Kim emphasized the role of Wi-Fi advancement in this process. At the same time, the Connectivity Development Team developed and completed the commercialization of the latest specification (BT5.2), Bluetooth and GNSS that successfully entered the Flagship by applying L5 satellite and sensor correction technology for high-performance positioning, and recently indoor positioning with accuracy within several centimeters. Kim explained that if UWB technology, which has been developed for measurement and is in preparation for its first commercial use, can be combined, it can exert strong power in many high-spec IoT services and applications in the future.

“To help our latest products lead the market standard, to secure competitiveness and sustainability in the future and to make sure stability and compatibility are achieved well in advance, I personally hope that we implement wireless access points¹¹ and enter the relevant product market to do so,” Kim said.

Protecting Your Privacy on Smartphone: Security That Strengthens a Separate Security Operation Environment (iSE)

Smartphones play a lot of roles these days. Two particularly significant such roles are identification cards and wallets. Take biometrics, mobile identification (eID) and Samsung Pay, for example. These services often require users to verify their identity, and there is always the possibility that hacking can occur in the process of user verification. As such, a level of security that goes beyond the software level is called for, which means it is required on the hardware level and even in semiconductors.

The semiconductor that provides security in smartphones is called the Secure Element (SE) semiconductor. There is a separate embedded Secure Element (eSE) located outside the SoC, but, with Exynos 2020, an integrated Secure Element (iSE) is embedded in the security block inside the SoC.

“The name we have given to the project that focuses on iSE embedded in Exynos is ‘STRONG,’ which is an abbreviation of Secure Tamper-Resistant of Next Generation,” said Jongwoo Lee, Vice President of the Design Platform Development Team. “The iSE is a separate environment within the SoC that operates security programs. The iSE plays not only the role of the eSE — which can be separately embedded on the outside — but it can control the security of the SoC as well. Advanced processing means it boasts high performance, and it also enables safe expansion to external memory, such as DRAM and Flash. These many roles can be taken even further and protect the SoC in the active security module.”

▲ (From left) Keunyoung Park from the AP S/W Development Team, VP Jongwoo Lee, PL Bogyeong Kang and Sunghyun Kim from the Design Platform Development Team are doing their utmost to strengthen the security environment in mobile devices.

The iSE is used for device security and security services. Device security is focused on strengthening the security of the device itself, and security services are focused on the information of users that is held within mobile devices, like mobile identification, payment and car keys.

“At the beginning of this year, we finished the PoC (Proof of Concept) and succeeded in developing the iSIM,¹² the most applicable service using iSE,” Lee said. “This was a result of close cooperation between Samsung Research, which is in charge of the iSE Secure OS (Camelia), and the digital security company Thales, which is in charge of developing the iSIM Secure Application.”

The iSIM is an upgraded version of the embedded SIM (eSIM) and it integrates the function of the SIM within the SoC. This provides convenience for users because it allows them to change their mobile carrier without changing their SIM card, have more than two phone numbers at once and make use of various mobile carrier services on one device. From the perspective of smartphone manufacturers, the iSIM provides advantages as well, because it lets them remove the SIM card slot and reduce the space needed for parts: iSIM can be operated within the SoC without a separate semiconductor, as is the case with discrete eSIM.

▲uSIM, eSIM and iSIM size comparison

What makes the development of the iSIM so significant is the extreme difficulty developers encounter in meeting the technological environment requirements for embedding iSIM.

“The iSIM needs to meet Global System for Mobile Communications (GSMA) requirements,” said Lee. “That means embedding the iSIM over the OS software and hardware above a certain security level, a level called CC EAL4+.¹³ However, we have hardware that operates one level higher than this guideline: CC EAL5+. We also have secure external memory where large SIM profiles can be embedded.”

“We are the only company that can provide both the eSE and iSE, which are the basis for the eSIM and iSIM,” Lee continued. “So we can provide solutions that smartphone manufacturers can easily and flexibly adopt. Personally, I believe there is no such thing as ‘perfect’ in the area of security, but we are working hard to get as close to perfect as is technologically possible. Our teams will continue to make constant effort in providing a high-level security operation environment that can accommodate the many different security features different platforms provide.”

¹ Digital communication: A method of converting an analog signal into a digital signal, transmitting it to the other party and converting it back into an analog signal that can be recognized by humans. High-quality and large-capacity communication are possible compared to analog communication.

² Mobile broadband: A technology that provides high-speed multimedia Internet services to mobile devices such as smartphones and tablet PCs.

³ New Radio (NR): A 5^th generation mobile communication technology. Consists of sub-6 GHz and mmWave (millimeter wave, high frequency band of 24-100 GHz band). Although mmWave has the advantages of ultra-high speed, ultra-low latency and super-connectivity, it has the disadvantage of poor diffraction.

⁴ Institute of Electrical and Electronics Engineers (IEEE): An American association of electrical and electronic engineers and the world’s largest technical organization.

⁵ 3^rd Generation Partnership Project (3GPP): A mobile communication standardization technology cooperation organization founded in December 1998 to establish international standards related to wireless communication, such as GSM, WCDMA, GPRS and LTE.

⁶ Ultra-Wideband (UWB): A technique that lowers maximum transmit power to less than -41.3 dBm/MHz so as not to interrupt other wireless. However, it uses wide bandwidth (500MHz) to achieve comparably high data rates.

⁷ Quality of Service (QoS): This refers to the guarantee of communication service quality, delay time or data loss rate below a certain level on the network. It also refers to a communication service level agreed or defined in advance. In other words, it is a generic term for various technologies that intelligently match the transmission demand of various applications to a given network resource by allocating network resources such as bandwidth and priority in order to send data to a destination quickly, at a constant speed and reliably.

⁸ Multi-Link Operation (MLO): The technology that operates various channels of different frequency bandwidths at the same time.

⁹ 4096 QAM (Quadrature Amplitude Modulation): A modulation method for transmitting data by shifting and adjusting the amplitude and phase of the in-phase carrier signal and quadrature-phase carrier signal. It is advantageous when a large amount of data needs to be transmitted in a narrow transmission bandwidth. 12bits per symbol in a 4096QAM

¹⁰ Source: <Cisco VNI predicts bright future for Wi-Fi towards 2022> February 22, 2019

¹¹ Wireless Access Point: The low-power wireless device that plays the role of a base station in wireless LAN. It is also referred to as a Wi-Fi extender, Wi-Fi amplifier or wireless extender.

¹² iSIM (integrated SIM): A built-in subscriber identification module. Also called ieUICC (integrated embedded universal integrated circuit card)

¹³ Common Criteria Evaluation Assurance Level (CC EAL): Common Criteria (CC) is an international standard for evaluating the security of IT products and certain websites. Evaluation Assurance Level (EAL) is a grade that is assigned to evaluation assurance.