As wireless communication continues evolving to have shorter wavelengths (high frequencies) to accommodate high data transmission rates, sub-GHz communication has remained relevant in some applications, such as IoT. This long wavelength provides a unique set of characteristics that are suitable for various IoT use cases.
This article highlights what sub-GHz communication is, its devices, communication standards, benefits, and application areas in IoT that utilize these unique characteristics. Read on to learn more!
What Is Sub GHz Communication?
Also known as the sub-giga band, sub-GHz wireless communication refers to radio frequency communication that operates at frequencies lower than 1 GHz. This communication is usually in the 769–935 MHz and 315–468 MHz ranges.
Unlike other wireless communication protocols like BLE and Wi-Fi, the specific frequency for these sub-GHz protocols is not standard. It varies depending on the country or region. But all these frequencies provide long-range transmission and low power consumption, making them ideal for IoT applications.
Sub-GHz Wireless Communication Standards
Indeed, broadly speaking, Sub-G refers to any frequency band below 1GHz. Technologies like Z-Wave and LoRaWAN operate within the Sub-1GHz range. In practical usage, Sub-G often denotes various enterprise-specific Sub-G protocols or proprietary transmission methods with the following advantages:
Long Transmission Range: Low-frequency signals have longer wavelengths, which can penetrate obstacles and cover larger areas, offering better performance compared to the 2.4 GHz band.
- Low Power Consumption: Sub-1GHz technologies generally consume less power, making them well-suited for battery-powered devices that need to operate for extended periods.
- Less Interference: The 2.4 GHz frequency band is commonly used and can be crowded, whereas Sub-1GHz bands are relatively less congested, effectively reducing interference and improving connection reliability.
- Narrowband Mode: Sub-1GHz solutions can operate in narrowband mode, which reduces interference and increases the link budget, further extending the connection range.
These advantages make Sub-1GHz technologies particularly appealing for applications in the Internet of Things (IoT) and wireless sensor networks (WSN). Various Sub-1GHz technologies such as LoRaWAN, Z-Wave, and RBF have unique characteristics and are suited for different application scenarios.
Z-Wave
Z-Wave is primarily used for commercial and residential building automation, and it uses the part 15 unlicensed ISM (Industrial, Scientific, and Medical) band for these applications.
Its frequency varies depending on the region, with the North American band ranging from 908–916 MHz when operating as a mesh and 912–920 MHz when operating in long-range, star topology mode. In Europe, the band ranges from 868–869 MHz.
Globally, Z-Wave frequencies range from 862.5 MHz to 926.3 MHz, smart Z-wave Gateway can act as hub, allowing Z-wave devices to work together, and thus building up smart connected homes with remote access.
ZigBee
ZigBee operates in both the sub-GHz and GHz levels, taking advantage of the IEEE 802.15.4 physical radio standard and operation in unlicensed bands globally. The international frequency standard is 2.4 GHz (like Wi-Fi and Bluetooth), but the European ZigBee frequency is 868 MHz and 915 MHz for the Americas. The transmission distance for these sub-GHz ZigBee frequencies can reach 1 km or more. Zigbee gateway can also act as a bridge between Zigbee smart devices (relays & sensors & actuators) and cloud based applications and product. LTE 4G, Wi-Fi and Ethernet backhaul avaliable.
Learn More:
- What is Zigbee and why is it important for smart home?
- Zigbee Vs Z-Wave: Which is Better for Home Automation
- What is Z-wave and How does is work?
Dusun IoT offers muti-protocol supported IoT Gateway whether it’s cellular (LTE CAT M1, LTE CAT1), or 2.4 and 5 GHz Wi-Fi, or Zigbee, Z-Wave, BLE, LoRa, Modbus and CAN.
LoRaWAN
LoRaWAN is a long-range wide-area network communication protocol whose frequency bands are split into five major regions.
- 863–870/873 MHz in Europe (EU868)
- 902–928 MHz in North America (US915)
- 915–928 MHz in South America (AU915/AS923-1)
- 865–867 MHz in India (IN865)
- 915–928 MHz in Asia (AS923)
It uses a wide bandwidth (7.8 kHz-500 kHz) and provides up to 37.5 kbps data rate.
LoRaWAN gateway serves as the backbone of the LoRaWAN IoT architecture’s star topology network. It gathers data from LoRaWAN devices and transmits it to the LoRaWAN network server.
Learn More: How To Build a LoRaWAN Network
Wi-SUN
Wi-SUN is an acronym for Wireless Smart Utility Networks, a wireless communication protocol built specifically for interconnecting smart grid devices. It has a coverage of up to 4 km and uses various frequency bands ranging from 470 MHz to 928 MHz in some parts of the world. For other regions, the protocol operates in the 2.4 GHz range.
RBF
Developed by Roombanker, RBF is a private sub-GHz two-way radio communication protocol that boasts of:
- High-security levels (AES-CCM encryption and random number key)
- Anti-jamming (frequency hopping spread spectrum)
- Multi-frequency bands for regional adaptability (915, 868, and 433 MHz)
- Long 3.5km range
- Real-time downlink data transmission in low-power mode
You can use the RBF smart home security hub with its compatible PIR sensor and indoor siren. The hub also features Bluetooth and ZigBee wireless protocols, so you can integrate it with other IoT devices.
Sub-GHz Wireless Communication Comparison
| Protocol | Frequency Range | Coverage |
| Z-Wave | 862.5–926.3 MHz | 1.6 km+ |
| LoRaWAN | 433–928 MHz | 15 km+ |
| ZigBee | 868–915 MHz | 1 km+ |
| Wi-SUN | 470–928 MHz | Up to 4 km |
| RBF | 433–915 MHz | Up to 3.5 km |
What Are Sub GHz Devices?
Sub GHz devices are hardware components that communicate using RF signals in the MHz range. They include:
IoT Gateways
IoT Gateways are the devices that create the IoT network and perform edge processing. Some operate on one frequency to run a particular wireless protocol, while others run multiple protocols in the sub-GHz and GHz ranges.
The latter (multiprotocol gateways) is more practical because such hubs can support more networks and devices. Some examples are the DSGW-030-3 Z-Wave Home Automation Hub and DSGW-210-F18 Zigbee Z-Wave Gateway, which support Z-Wave in the sub-GHz range.
IoT End Nodes
End nodes include components like sensors, thermostats, smart lights, smart meters, alarm sirens, surveillance cameras, wearables, etc. These are either the sources of data or the data consumption points, and they communicate with the gateway via the sub-GHz frequencies.
Other sub-GHz devices are:
- Walkie talkies
- Remote controls
- VHF and UHF devices
Why Are Sub GHz RF Preferred for IoT Solutions?
Long Range
Arguably the biggest advantage of sub-GHz radio frequencies is their long range. All the communication standards described above have a wireless range of at least 1 km, with LoRaWAN exceeding 15 km in open spaces.
To put it into perspective, Wi-Fi and BLE have a coverage of about 150–300 feet, although BLE long-range can reach up to one kilometer.
Low Power Consumption
The long-range, low bandwidth properties of sub-GHz communication make it more energy efficient than GHz protocols like Wi-Fi. This energy efficiency makes the sensors and other end nodes suitable to run using batteries, which last for years before requiring replacements.
Less Interference
Bluetooth and Wi-Fi crowd the 2.4 GHz spectrum, so communication in this band is more susceptible to interference from routers, computers, phones, PC peripherals, and other wireless devices. But sub-GHz communication is not crowded, which makes it more reliable for wireless data transmission.
Penetrates Obstacles Easily
Sub GHz radio frequencies have long wavelengths that penetrate through walls more easily than RFs with short wavelengths. Therefore, they can reach further in city environments, factory floors, and assembly plants.
Supports Multi-Hop Communication
Another benefit of sub-GHz communication is it supports multi-hopping to extend the range of the wireless signal. This extension requires repeaters or end nodes in a mesh network, which are cheaper than installing multiple gateways.
Key IoT Application Areas of Sub GHz Communication and Devices
Smart Grids and Metering
Power utility companies use sub-GHz wireless communication protocols to manage and monitor them remotely for things like optimizing consumption to maximize energy efficiency. These low frequencies have a long-range and consume little power, making them viable for smart grids and metering.
Industrial Control
Since sub GHz frequency spectrums are not as crowded as the GHz protocols, they experience less interference, which is critical in industrial control applications because the environment is noisy.
Additionally, the long-range and strong penetration properties are ideal for large factories and manufacturing plants because they enable end nodes and gateways to communicate seamlessly across the floors.
Home and Building Automation
Sub GHz communication consumes very little power, so devices can take a long time before you have to replace batteries in smart home/building automation systems. This results in minimal maintenance tasks and costs. These Z-Wave sensors, for instance, have a battery life of at least 1 year, with the door/window sensor capable of running for 10 years on a CR2 battery, which is impressive.
Smart Cities
Smart cities consist of smart distributed systems, such as street light controllers, parking management systems, and air quality control monitors. Interconnecting the devices that run, collect, and consume data for these systems requires long-range wireless capabilities to cover the expansive urban areas, and sub-GHz protocols excel at this.
Smart Agriculture
Like smart cities, smart farms can cover large areas, especially those involving industrial, mechanized agriculture. Additionally, farming requires precision, so it is important to keep tabs on various parameters regularly across the entire space. These include soil moisture levels, temperature, livestock movement, crop growth, etc.
Therefore, a smart agriculture solution needs multiple sub-GHz sensors distributed across the farm, with the sub-GHz gateway installed somewhere in the middle.
Challenges With Sub GHz Communication
Slow Data Transfer Speeds
The most significant letdown of sub-GHz communication is the slow data transfer speeds. For instance, LoRaWAN speeds range from 250 bps to 22 kbps. ZigBee speeds are almost similar at 20 kbps, while Z-Wave can reach 100 kbps.
RBF is among the fastest because it reaches up to 1 Mbps. However, these transmission rates are sufficient for the applications discussed above.
Non-Standard Frequency Bands
Unlike the GHz communication protocols, sub-GHz communication frequencies vary depending on the country or region, and these differences can make global deployment challenging.
Wrap-Up: Why Choose Our Sub-GHz IoT Solutions
Self-Developed Sub-GHz Protocol Support
For those partners who want to develop or use their own private Sub-GHz protocol in the gateway, we can put pin2pin subg module on the gateway, and develop the driver of the subg. We have strong expert team on Sub-Ghz protocol and have developed a private Sub-GHz protocol for a company of Dusun – Roombanker, focusing on Smart Security & Automation Solution.
Vertically Integrated Design
From the hardware perspective, Dusun manufactures IoT end nodes and gateways for various applications. These devices are vertically integrated to communicate and send data via sub-GHz wireless protocols.
This integration simplifies IoT solution deployment because you don’t have to worry about the hardware part of the project. And for software development, our gateways feature built-in integration with well-known cloud platforms like AWS, Azure, and Thingsboard.
Some even come with pre-installed applications, such as Home Assistant, which significantly reduces the time to market.
Solid, Secure, and Stable Data Transmission
The RBF protocol implements features like Time Division Multiple Access (TDMA), Listen Before Talk (LBT), Frequency Hopping Spread Spectrum (FHSS), and AES-CCM encryption to ensure the data transmission is solid, secure, and stable from the end nodes to the gateway and back.
Wide Frequency Range Support
Sub GHz communication frequencies vary depending on the country or region, and our hardware supports all these variations. When you develop the hardware with us, you can select the specific frequency you want from the available options, such as the one provided in the model list of this DSGW-014 outdoor LoRaWAN gateway.
Interoperability
Although we provide vertically integrated products, this doesn’t mean that you can’t interface them with other third-party devices and software. It is possible to use our hardware to upgrade an existing IoT system or build a new solution using individual components or vertically integrated hardware. Either way, we only need a few details to give you a quote for your project. Fill in our contact form today, and we’ll be in touch.
FAQs
What Are Sub GHz Devices?
Sub GHz devices are electronics that transmit data wirelessly using RF signal frequencies lower than 1 GHz.
What Are Sub GHz Signals Used For?
Sub GHz signals are used for long-range wireless communication in IoT devices, walkie-talkies, utility meters, etc.
What Is the Frequency of Sub GHz Devices?
Although the frequency of sub-GHz devices refers to anything below 1 GHz, the most commonly used ones are 868 MHz and 915 MHz. Sub-GHz wireless IoT protocols use these frequencies for signal transmission.
