The Internet of Things has transformed industries, cities, and homes worldwide. The number of connected devices is projected to exceed 2530 billion by 2030, and these are wearables accessible to consumers, industrial sensors, smart meters, and healthcare monitors. Such devices may have dramatically different communication requirements, with some at any given moment transmitting small amounts of telemetry with infrequent updates, and others having requirements of real-time video or highly fidelity data.
Both the narrowband IoT and LTE-M are conventional LPWAN technologies, but have been optimized to enable ultra-low power, low-data-rate IoT, and cannot meet the moderate throughput and latency requirements of mid-tier IoT applications. On the other hand, 5G NR has the capability of high speed with milliseconds latency, more complex devices, bigger antennas, more networked devices, and more power consumption. Between LPWAN and the full 5G lies lots of IoT use, including AR/VR wearables, industrial automation sensors, and smart city infrastructure.
Connectivity Challenges in Mid-Tier IoT
One of the most significant design constraints is battery life with regard to the creation of IoT devices. A lot of devices, such as wearables, environmental sensors, and industrial monitors, are likely to last 5-10 years without a battery change. LTE-M and NB-IoT are very effective in providing ultra-low power usage, but fail to be useful with moderate-throughput applications. Conversely, full 5G is fast, but it is very power hungry and requires larger batteries or recharging.
The 5G RedCap solutions will deal with this problem with intelligent energy-saving methods:
- Power Saving Mode (PSM): Devices are kept alive on the network, but they go to sleep taking long durations before they are awakened to transmit or receive information.
- Extended Discontinuous Reception (eDRX): Minimizes the paging cycles, even reducing the idle power.
Combined, these attributes enable RedCap equipment to operate up to several years on standard lithium-thionyl chloride batteries, despite the ability to operate with moderate-speed connectivity.
Coverage is another critical factor. Many IoT devices are deployed in tough environments:
- Basements and tunnels
- Industrial sites
- Rural locations with weak signals
Conventional Wi-Fi and BLE tend to fail in this case, and full 5G would need dense infrastructure, which is costly to install. Red capacity is enhanced by the compatibility of the link budget with superior coverage functions and provides 15-20 dB of extra signal power over conventional 5G NR. This guarantees good connectivity even in the deep indoor areas or faraway places.
Mid-tier IoT implementations, such as smart city streetlights, parking meters, and industrial sensors, may have tens of thousands of devices per location. To enable this to be scalable and cost-effective:
- The device modules should not exceed $10/unit.
- Thousands of devices must be supported on networks at once.
RedCap eases the design of devices by eliminating the number of antennas and RF chains and provides high-scale deployment without compromises in performance.
Lastly, other IoT uses require more than low power levels; they require more throughput and low latency. Examples include:
- AR/VR wearables with immersive data.
- Video or high-rate telemetry on an industrial sensor.
- Monitors of the environment that deal with several streams of data at once.
RedCap steps up to the task, with the capability to support downlink speeds of up to 220 Mbps and a latency of 1050 ms, which is best suited to middle-level IoT devices that demand near real-time response.
Technical Foundations of 5G RedCap
Overview
5G RedCap is a streamlined 5G NR variant designed for mid-tier IoT devices that need moderate throughput, low latency, and long battery life. It works in both Frequency Range 1 (FR1, sub-6 GHz) and Frequency Range 2 (FR2, mmWave). In FR1, the bandwidth is limited to 20 MHz, providing sufficient speed for applications like AR/VR wearables, industrial sensors, and smart city infrastructure without the cost and complexity of full 5G NR.
Hardware Simplification
To reduce complexity and cost, RedCap limits the number of:
- Antenna chains
- RF chains
- MIMO layers
This makes devices smaller, energy-efficient, and easier to deploy. Small form-factor wearables, industrial sensors, and street-level infrastructure can be installed at scale without bulky or expensive hardware.
Coverage and Reliability
RedCap improves connectivity in challenging environments, including:
- Basements and underground spaces
- Remote rural locations
- Industrial facilities
It achieves this through:
- Narrowband channel allocation
- Repetition schemes for robust transmission
- Lower bandwidth operation
The link budget is improved by 15–20 dB, ensuring devices remain connected where standard 5G NR might struggle.
Power Efficiency
Battery life is critical for IoT devices. RedCap supports long-term energy savings through:
- Power Saving Mode (PSM): Devices stay registered while sleeping for long periods.
- Extended Discontinuous Reception (eDRX): Reduces paging frequency and idle current.
These mechanisms allow devices to operate for multiple years on a single battery, even when transmitting regular telemetry.
Device Density and Scheduling
A single RedCap cell can support thousands of simultaneous devices, making it ideal for dense urban deployments. Network scheduling is optimized to:
- Prioritize small, periodic uplinks like sensor data
- Efficiently manage occasional downlink commands.
Security
RedCap leverages the full 3GPP security framework, including:
- SIM-based authentication
- Mutual encryption
- Integrity protection
This ensures that RedCap devices can be securely deployed in mission-critical environments, such as healthcare monitoring and industrial automation.
Real-World Applications
Industrial IoT
RedCap offers a combination of throughput, coverage, and energy efficiency that can be used by sensors to monitor temperature, vibration, pressure, and equipment status. Manufacturing predictive maintenance systems can be used to send high-resolution vibration data to prevent equipment breakdowns, which minimizes downtime by up to 2025.
Wearables and AR/VR Devices
RedCap can also be used to allow wearables and AR/VR to work with moderate latency, so that they can be used in an immersive experience without the need to charge frequently. Smartwatches and fitness trackers can be used to send high-frequency sensor data, and the devices have significant battery life.
Smart Cities
City networks, such as streetlights, parking meters, traffic cameras, and environmental sensors, are based on the scalable connectivity of RedCap. Smart streetlights will also regulate their brightness based on activity, which can save their electricity consumption up to 30 percent, whereas smart waste bins will notify the collection services when they are full, eliminating unnecessary routes and fuel consumption.
Healthcare Monitoring
Extended coverage and long battery life are advantageous in remote patient monitoring devices, e.g., glucose monitors, pacemakers, and emergency alerts. RedCap can be used to have round-the-clock monitoring even in remote areas where there is no broadband.
Comparison with LTE-M, NB-IoT, and Full 5G
| Technology | Data Rate | Latency | Coverage | Power Efficiency | Best Use Case |
| NB-IoT | Tens of kbps | Seconds | Deep indoor | Very high | Smart meters, environmental sensors |
| LTE-M | Up to 1 Mbps | 1–2 sec | Moderate | High | Wearables, asset tracking |
| 5G RedCap | Up to 220 Mbps | 10–50 ms | Extended | High | Mid-tier IoT, AR/VR, industrial sensors |
| Full 5G NR | >1 Gbps | <10 ms | High (dense deployment) | Moderate | Video streaming, autonomous vehicles |
RedCap fills the mid-tier connectivity gap, providing moderate throughput and latency suitable for industrial, wearable, and urban IoT deployments.
Design Considerations for Engineers
- Antenna design: Small antennas suffice for sub-6 GHz deployments; metal enclosures or underground placements must be tuned.
- Module selection: Ensure modules support operator bands and RedCap features.
- Battery and power management: Lithium-thionyl chloride batteries with supercapacitors are recommended.
- Firmware updates: Use incremental OTA updates to minimize energy and bandwidth consumption.
- Hybrid networks: RedCap can coexist with BLE, Matter, or Thread for local interactions and cloud connectivity.
Future Outlook
Hybrid Connectivity
The use of RedCap in conjunction with local protocols allows smart homes and industrial locations to interact among themselves and be connected to the cloud.
Edge Intelligence
Intense use of low-power AI accelerators processes data locally and only transfers events that have relevance to the cloud, minimizing bandwidth consumption and latency. Anomaly notifications can only be provided by industrial vibration sensors, e.g.
Non-Terrestrial Networks (NTN)
RedCap integration with low-earth-orbit satellites provides worldwide connectivity to maritime, mining and agriculture.
Enhanced Security
Incorporation of post-quantum cryptography will provide long-term security against all quantum computer threats and safeguard the industrial and healthcare IoT data.
Shaping the Future of Mid-Tier IoT
5G RedCap is an intermediate step between LPWAN technologies and full 5G NR with moderate throughput, low latency, energy efficiency, and wide coverage. It supports a wide variety of applications, including industrial sensors, AR/VR wearables, smart city infrastructure, and healthcare monitoring.
RedCap has the capacity to absorb high device density and coexist with local protocols, hence providing scalable and flexible solutions to mid-tier IoT deployments. Its implementation will be pivotal in creating resilient, secure, and andenergy-efficientt Internet of Things (IoT) networks that can support the needs of billions of interconnected devices in the forthcoming decade.
