5G RedCap: The key to continued IoT growth

Preface

The first 5G New Radio (NR) network was launched in April 2019, and 202 networks have been launched in 79 countries since then. Omdia predicts that the number of 5G connections worldwide will approach 6.8 billion by the end of 2027. However, most connections are concentrated in smartphones, and large-scale 5G Internet of Things (IoT) has not yet been realized.

3GPP has defined 5G standards, which are almost all focused on consumer smartphones and high data throughput/low latency use cases. Many IoT applications do not require these features, and they will introduce significant complexity to the design, manufacture, and operation of IoT devices. Furthermore, the added costs will outweigh the potential benefits, making large-scale IoT unattainable – at least in the mid-range connectivity space.

3GPP announced the 5G RedCap standard in the Release 17 specification to meet the demand for mid-range 5G connectivity. RedCap will enable the evolution from 4G mid-range connectivity options (LTE Cat-1/1bis and LTE Cat-4). This report provides the latest developments in 5G RedCap through 2023 and explores why this technology will be key to the continued growth of the Internet of Things.

What is 5G RedCap?

3GPP defined the 5G specification in 2018, which includes three pillars: enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC). eMBB and URLLC are considered to challenge the limits of technological progress and are designed to demonstrate the incredible high throughput and low latency characteristics of 5G in the future. At the same time, mMTC uses low-power wide-area (LPWA) connection technology to connect a large number of devices at a low cost.

While these new technologies have made progress in functionality, it has become clear in recent years that many IoT use cases do not require the high speeds or low latency provided by eMBB and URLLC. However, they require better functionality than mMTC. Therefore, 3GPP has introduced a lightweight version, 5G RedCap, to meet use cases that require mid-range connectivity.

The 5G RedCap released by 3GPP R17 in 2022 includes the following key features:

• Reduce equipment complexity, thereby reducing equipment costs

- Maximum bandwidth is 20 MHz in Sub-7GHz and 100 MHz in mmWave — Single carrier, so no support for carrier aggregation or dual connectivity

-Use a single receiver in the Sub-7GHz band

- Reduces device memory requirements

• Reduce power consumption

- Enhanced low power mode with support for extended enhanced discontinuous reception (eDRX) and lower transmit power

- Relaxation of radio resource management measures

• Data transmission rate at least as high as LTE Cat-1

-Downlink rate is 150Mbps, upstream rate is 50Mbps

- Latency targets are 100ms for industrial sensors and 500ms for video surveillance (minimum requirement) – but 5G RedCap can achieve lower latency

- One transmitting antenna and at least one receiving antenna (up to two can be selected)

We have listed some potential use cases of 5G RedCap in the IoT ecosystem below, but all medium-speed IoT use cases can use 5G RedCap:

• Sensors: pressure sensors, humidity sensors, temperature sensors, motion sensors, accelerometers, and actuators

• Industrial Wireless Sensor Networks

• Surveillance cameras: smart cities, factories and other industrial sites

• Wearables: smart watches, rings, electronic health devices and medical monitoring devices

• Smart Grid

• Point of Sale (POS)

• Smart Meters

• Telematics

• Industrial Internet of Things (IIoT): augmented reality headsets, automated guided vehicles and robotic controls

3GPP R18, scheduled for release in the first quarter of 2024, will include additional features. Specifically, R18 will focus on IoT devices with performance between 3GPP R17 RedCap and existing LPWA devices such as LTE-M and NB-IoT. It should be noted that this category should not overlap with LPWA, as LPWA has better power consumption and coverage indicators.

New features/functionality being considered include:

• Higher data transfer rates than those specified in R17

• Positioning: Location-based service applications (such as asset tracking)

• Device-to-device protocol (sidelink): Devices (such as wearables) can communicate directly with nearby smartphones or connected vehicles

• Support the use of unlicensed spectrum

• Further reduce the complexity and cost of 5G RedCap user equipment

It is also worth noting that the 5G RedCap device types expected in Release 18 are similar to LTE Cat-1 and Cat-1bis, and will have a 10Mbps data rate (downlink) capability. This capability makes RedCap very suitable to be a long-term successor to these LTE categories.

Omdia Analysis

4G mid-range connectivity technologies (LTE Cat-1, Cat-3 and Cat-4) make up the bulk of module shipments

Figure 1 shows the percentage of IoT modules shipped that are LTE Cat-1, Cat-3 or Cat-4 modules compared to other modules (including all 2G, 3G and the remaining 4G and 5G modules). The medium-speed 4G LTE standard (Cat-1, Cat-3 and Cat-4) is the most popular and widely used cellular IoT standard in the world, accounting for 50.3% of module shipments in 2023.

1. Figure 1: Over half of modules (50.3%) shipped in 2023 are either LTE Cat-1, Cat-3, or Cat-4

Compared with the low-speed LTE category, the 4G LTE Cat-1, Cat-3 and Cat-4 standards provide optimized data transmission rates and latency; compared with the high-speed LTE category, its hardware price is more competitive and less complex. In contrast, the 5G standard currently does not have a medium-speed application corresponding to the LTE Cat-1, Cat-3 and Cat-4 in the 4G standard; the 5G standard only proposes three extreme scenarios: eMBB, URLLC and mMTC.

4G mid-range connection technology has not evolved

Currently, 4G mid-range connectivity technologies such as LTE Cat-1, LTE Cat-1bis, LTE Cat-3, and LTE Cat-4 have not evolved. As mentioned in the introduction to this report, high-performance technologies such as eMBB and URLLC will be the continuation of higher-tier LTE technologies (between LTE Cat-6 and Cat-24). Lower-tier technologies such as 2G and 3G will switch to mMTC (NB-IoT or LTE-M) networks in the coming years, especially as many 2G and 3G networks have been shut down. Therefore, 5G mid-range connectivity technologies are particularly needed to ensure the longevity of IoT devices/use cases currently using 4G technology. At least in the long term, devices currently using LTE technology will face the risk of network decline without corresponding 5G mid-range connectivity technologies. After the complicated journey of switching from 2G/3G to NB-IoT/LTE-M, no one wants to see this happen again.

Logically, RedCap would be an evolutionary technology for LTE Cat-1/1bis and LTE Cat-4, as the design standards are very similar and can be used for the same use cases. Consider the following example:

• Qualcomm’s QCX216 LTE Cat-1bis chip was launched in December 2022; according to the product description, it is designed for use cases such as smart water and electricity meters, trackers, e-metering, and smart cities. UNISOC is the largest player in the LTE Cat-1bis space, and its 8910DM module has been deployed in payment systems (POS), smart meters, and industrial control systems. These use cases are slightly more limited in size than LTE Cat-1 use cases – LTE Cat-1 requires two antennas, while LTE Cat-1bis only requires one antenna.

• The technology has been developing very well since LTE Cat-1 was released by 3GPP R8 in 2008. It has been deployed in industrial automation, telematics, video surveillance, digital signage, and payment systems (without much size limitation).

• Electric vehicle (EV) charging stations are a rapidly growing use case for mid-range connectivity technologies. In recent years, EVs have received strong government support, such as the U.S. Infrastructure Act, which will build 500,000 charging stations by 2030. There are similar initiatives in the UK, requiring all new homes, workplaces, and shopping centers to have EV charging stations. These devices will generate data that is useful to drivers and charging station operators, such as usage-based analytics, battery condition data, and billing information. They will require connectivity technologies that can handle sufficient data throughput and are cheap enough to install and operate; therefore, mid-range connectivity technologies are best suited for these devices.

These are the use cases that the 5G RedCap will be designed to support, ensuring these devices are able to connect to next-generation telecoms networks after 4G is switched off (many are expected to be between 2030-2040).

Source: Omdia