[IoT Communication Technologies] — Cellular Communication

Overview

When discussing IoT communication, one technology that cannot be bypassed is cellular technology. We interact with cellular networks every moment of every day; they have become an integral part of our lives. A cellular network is a mobile communication architecture, categorized into analog and digital based on the type of data transmitted. When we make phone calls, send messages, or engage in video communication via mobile phones, the phone wirelessly connects to a nearby cellular base station, which in turn connects to other base stations or the internet through wired means.

Why has cellular IoT become a primary technology for the Internet of Things? Firstly, cellular networks are widely prevalent, covering over 90% of the global population. Secondly, operators have made massive investments in cellular infrastructure to provide secure and reliable services to as many customers as possible. By leveraging existing infrastructure and mature technology, cellular IoT can connect millions of IoT devices with minimal additional investment. Thirdly, thanks to cellular IoT, just as my smartphone can connect to a base station tens of kilometers away, so can IoT devices.

Development History

1G - First Generation Cellular Mobile Communication Technology

In the 1970s, the Advanced Mobile Phone System (AMPS) was first successfully developed by Bell Labs in the United States. This marked the first time people could truly use a large-capacity cellular mobile communication system with anytime communication capability. Mobile phones began with 1G technology in the 1980s. 1G is the first generation of wireless cellular technology. Supporting voice calls only, it was an analog technology. Phones using it suffered from poor battery life, voice quality, security, and were prone to dropped calls. FDMA (Frequency Division Multiple Access) is one of the primary technologies in data communication, which involves placing mobile users in channels with the same time interval but different frequencies.

The maximum speed of 1G technology was 2.4 Kbps.

2G - Second Generation Cellular Mobile Communication Technology

When upgrading from 1G to 2G, mobile phones received their first major upgrade. The GSM (Global System for Mobile communication) network, operating in the 900/1800MHz frequency bands, provided mobile users with corresponding voice services and data services. 2G phone technology introduced call and text encryption, as well as data services like SMS, picture messages, and MMS. Although 2G replaced 1G and was later superseded by newer technologies, it is still used globally.

The maximum speed for 2G using GPRS (General Packet Radio Service) was 50 Kbps. The maximum theoretical speed was 384 Kbps with Enhanced Data rates for GSM Evolution (EDGE). EDGE+ could reach up to 1.3 Mbps.

Before the significant leap from 2G to 3G wireless networks, there were lesser-known interim standards like 2.5G and 2.75G. 2.5G introduced a new packet-switching technology more efficient than 2G. AT&T was the first GSM network in the US to support 2.75G via EDGE (Enhanced Data for Global Evolution).

3G - Third Generation Cellular Mobile Communication Technology

The introduction of 3G networks in 1998 brought faster data transfer speeds, enabling you to use your phone for more data-intensive purposes like video calls and mobile internet access. The term "mobile broadband" was first applied to 3G cellular technology. The third-generation mobile communication system adopted Wideband CDMA technology, providing mobile users with both voice and data services simultaneously.

The first-generation cellular communication used FDMA (Frequency Division Multiple Access) technology, where different mobile stations occupied different frequencies. The second generation used TDMA (Time Division Multiple Access), where different mobile stations occupied the same frequency but at slightly different time slots. The third generation used CDMA (Code Division Multiple Access), where different mobile stations occupied the same frequency but each had a different random code sequence, so the number of mobile stations served by the same frequency was determined by the number of random codes. Wideband CDMA offered superior performance, with a wider operating bandwidth, stronger resistance to signal interference, and improved signal transmission capabilities.

The maximum speed for 3G was about 2 Mbps for non-mobile devices and 384 Kbps for moving vehicles.

4G - Fourth Generation Cellular Mobile Communication Technology

The fourth-generation network, released in 2008, is 4G. It supports mobile network access like 3G, as well as gaming services, HD mobile TV, video conferencing, 3D TV, and other features requiring high speeds. 4G innovated upon the previous three generations of communication technology to enhance wireless communication service functionality and internet speed. 4G technology is divided into two main categories: TD-LTE (Time Division Long Term Evolution) and FDD-LTE (Frequency Division Duplexing Long Term Evolution). TD-LTE refers to the improvement and enhancement of 3G technology's air interface access technology, using standards like Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO).

The maximum speed for a 4G network is 100 Mbps when the device is moving. For low-mobility communication, such as when the caller is stationary or walking, the speed is 1 Gbps.

5G - Fifth Generation Cellular Mobile Communication Technology

5G promises significantly faster data rates, higher connection density, lower latency, energy efficiency, and other improvements.

The expected theoretical speed for a 5G connection is up to 20 Gbps.

Characteristics of 5G Communication

• 5G is faster than 4G. 5G peak download speed is 20 Gbps, while 4G is only 1 Gbps; 5G is 20 times faster than 4G.
• 5G supports massive, fast data capacity. It uses unique radio frequencies to achieve what 4G networks cannot. 4G uses frequencies below 6 GHz, while some 5G networks use higher frequencies, such as around 30 GHz or higher.
• 5G has better interference resistance. Due to the strong directionality of high-frequency signals, they can be used alongside other wireless signals without causing interference.
• 5G can support over 1,000 more devices per square meter than 4G. 5G uses shorter wavelengths, allowing antennas to be much smaller than existing ones while still providing precise directional control.
• Since a single base station can use more directional antennas, 5G networks can broadcast ultra-fast data to more users with high precision and low latency.
• 5G transmission does not travel as far as 4G. Because ultra-high frequencies only work when there is a clear, direct line of sight between the antenna and the receiving device. Additionally, some of these high frequencies are easily absorbed by humidity, rain, and other objects. For these reasons, a strong 5G connection in your location might drop to 4G speeds when you move a few meters away. One solution is to use strategically placed antennas, which can be small antennas in buildings or large antennas spread throughout a city.
• This newer 5G network can more easily understand the type of data requested. It can switch to a low-power mode when not in use or when providing low rates to specific devices, and then switch to a higher-power mode for tasks like HD video streaming. 5G is 90% more energy-efficient than older networks like 4G.

About 3GPP

3GPP (3rd Generation Partnership Project), as the world's largest and most important international communications standards organization, unites seven telecommunications standard development organizations known as "Organizational Partners": ARIB (Association of Radio Industries and Businesses, Japan), ATIS (The Alliance for Telecommunications Industry Solutions, USA), CCSA (China Communications Standards Association), ETSI (The European Telecommunications Standards Institute), TSDSI (Telecommunications Standards Development Society, India), TTA (Telecommunications Technology Association, Korea), and TTC (Telecommunication Technology Committee, Japan). It provides a stable environment for its members to produce reports and specifications defining 3GPP technologies and has been instrumental in the development and commercialization of cellular mobile communication technology standards.

Established in 1998, its initial scope was to develop specifications for evolved GSM core networks and their supported radio access technologies (namely Universal Terrestrial Radio Access (UTRA) for both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) modes). The scope was subsequently modified to include the maintenance and development of technical specifications and reports for evolved 3GPP technologies beyond 3G.

The three Technical Specification Groups within 3GPP are:

• Radio Access Network (RAN),
• Services & Systems Aspects (SA),
• Core Network & Terminals (CT).

Since its inception, 3GPP has released multiple releases. A major focus of all 3GPP releases is to make the system as backward and forward compatible as possible to ensure uninterrupted operation of user equipment. The latest release is Release 18, which has an official 5G-Advanced logo for use on 3GPP reports and specifications starting from Release-18.

5G Cellular Mobile Application Scenarios

According to the Huawei 5G Era Application Scenarios White Paper, as cellular mobile communication continues to evolve, the 5G industry holds many future opportunities that are currently unfeasible.

• Virtual Reality (VR) and Augmented Reality (AR) are transformative technologies capable of completely颠覆 traditional human-computer interaction content.
• Connected Vehicles: Remote driving, platooning, and autonomous driving can only meet on-site needs with 5G.
• Smart Manufacturing: Wireless robot cloud control enables more lean, intelligent, digital, and flexible production.
• Smart Energy: Integrating renewable energy into the power grid improves reliability and reduces operational and maintenance costs.
• Telemedicine: Remote diagnosis, remote surgery, and remote monitoring are ensured with 5G technology.
• Wireless Home Entertainment: Ultra-HD 8K video and cloud gaming achieve high quality with 5G technology.
• Unmanned Aerial Vehicles (UAVs): Excel in professional inspection and security fields.
• Social Networks: Due to 5G's bandwidth and low latency, the live video streaming industry develops more rapidly.
• Personal AI Assistants can provide comprehensive information services for manufacturing and warehouse personnel.
• Smart Cities: Video surveillance and various sensing information promptly alleviate traffic congestion and ensure community safety.