System-on-Chips (SoCs) have become quite popular in IoT because they provide a compact package that does several functions, including data processing and wireless communication. As the name suggests, they are complete systems on chips.
But on the wireless communication aspect, SoCs are not the most powerful in terms of signal transmission. Also, they are not the most energy-efficient. Front-end modules beat SoCs in these two areas, and I’ll explain why you should use them in your IoT solutions.
What Are IoT Front-End Modules?
IoT front-end modules (FEMs) are integrated circuits specifically built to provide wireless connectivity. When paired with an SoC, the FEM forms an efficient IoT solution that extends the transmission range of the solution, as well as its battery life.
Front-End Module Features
Integrated Power Amp, Low-Noise Amp, and Switching Functions
The integrated power amplifier enhances the output power of the wireless signals being sent out to increase the range. On the other hand, the low-noise amplifier reduces the noise figure in the wireless signal.
FEMs also feature transmit/receive bypass switches and fast on/off switching times that help to extend the battery life. They have low sleep mode currents as well, which reduce power consumption to extend the battery life further.
Low Voltage Operation
Front-end modules generally operate at voltages lower than 3.6V, so you can power them using any battery chemistry you choose and across their discharge curves in the IoT device. SoCs with high current DC-DC converters built-in can also power FEMs.
Multi-User MIMO Operation
WiFi connectivity front-end modules usually feature multi-user MIMO operation to allow communication with multiple end nodes or clients at a time. This feature increases airtime efficiency.
Tiny Package
Whether in QFN or QFP packages, FEMs are tiny ICs that take up little real estate on the PCB.
Why Use Front-End Modules Instead of SoCs with Wireless Connectivity
Better Signal Sensitivity on the Receiver (RSSI)
RSSI (Received Signal Strength Indicator) is a measurement that shows how well a device can hear a signal. It is an important parameter because it helps to show if you have a strong enough signal to get a reliable wireless connection to transmit data. And the higher the RSSI value, the better/stronger the signal.
Combining SoCs with FEMs increases the RSSI value at the receiver because front-end modules have integrated amplifiers that increase the power output and reduce the noise figure.
Lower Power Consumption
Although FEMs have integrated power amplifiers that increase the power output, several other factors determine the power consumption in chipsets. These include:
- The amount of data sent (large packets require the radio to be on the air for longer during transmission, which draws more power)
- Advertising interval
- Processing power ( different layers of the protocol’s communication stack require certain amounts of processing to comply with the specifications and remain connected). Using a slow chip, such as an MCU, will lengthen the uptime, making the FEM draw more power.
FEMs paired with SoCs consume less power because the chipsets have fast on/off switching times that increase the processing speed to handle the protocol’s communication stack processing quickly.
Additionally, these chipsets have low sleep mode currents (less than 1 microampere), which reduce power consumption when idle. It is important to note that IoT wireless devices spend most of their lives in sleep mode.
Therefore, even if FEMs have higher transmit currents, especially in high throughput systems, they only transmit for a small percentage period throughout their operational life. Most of the battery drain comes from the power consumed during sleep mode, so a low sleep mode current is crucial in FEMs.
Dual Antenna Capabilities
Some front-end modules have two antennas to boost the transmit output power and increase the receiver’s sensitivity. The result is a more reliable connection, especially across long distances using protocols like Z-Wave, ZigBee, and BLE.
Better Data Transfer Rates Across Long Distances
FEMs also deliver faster data rates over long distances when compared to regular SoCs. Whether the connection interval for the transmission is long or short, FEMs maintain a relatively higher rate and better signal quality because of features like the power amplifier and LNA.
Applications of Front-End Modules?
- Smart thermostats
- Smart meters
- Wearables
- Health and fitness monitoring
- Smart home appliances
- Beacons
How To Integrate a Front-End Module To Your Project
Build a Custom Board To Hold the SoC and FEM
If you want to develop a custom IoT solution with a FEM from scratch, it is better to build an evaluation PCB. Optimize this circuit’s design and layout before transferring it into the production design.
You can even experiment with the FEM, comparing its performance (when paired with an SoC) to a similar SoC when operating alone. Each setup should be in its separate circuit board. Test for features like output power, sensitivity, range, data rate vs. range, etc.
Use a Ready-Made IoT Gateway That Supports FEMs
Since tests have already shown that FEMs paired with SoCs optimize the wireless transmission capabilities in IoT devices, you can use ready-made hardware to integrate an FEM for your IoT solution.
For instance, the DSGW-090 PoE smart hub with dual SIM card slots supports FEMs to enhance its wireless capabilities when communicating via BLE, Thread, Z-Wave, ZigBee, etc.
The hub features a WiFi-enabled router-on-a-chip SoC that can pair with any FEM of your choice to extend the transmission range. It converts the data transmitted using the supported wireless protocols on the FEM to WiFi, LTE, Ethernet, or Cat1 on the cloud connection side.
Conclusion
The most notable advantages of using FEMs with SoCs are a longer battery life and wireless range. Therefore, hubs like the DSGW-090 PoE smart hub are ideal for IoT solutions where the end nodes are distributed further out on a ZigBee, BLE, or Z-Wave network.
This gateway is not battery-powered, so power saving is not a big issue. However, you can incorporate transceivers with FEMs on battery-powered gateways or sensors to reduce maintenance costs associated with battery replacements.
We can partner to develop these hardware products to eliminate possible integration issues in your IoT solution. Whether you want custom FEM circuit boards, a ready-made DSGW-090 PoE smart hub, a custom energy-efficient gateway, or end nodes, we have hardware development experience and a robust R&D team that will ensure you deliver innovative products to your clients.
At Dusun, we value professionalism and flexibility, so we’ll be with you every step of the way to ensure you deploy to the market quickly, have lower development costs, and sort out any thorny customer-related issues in a short time. If you’re ready to get started on your IoT project with front-end modules, reach out to us with your requirements, and we’ll be in touch ASAP to discuss the finer details.
FAQs
What Is an RF Front End?
An RF front end refers to any circuit between the receiver or transmitter’s antenna and the mixer (modulator or demodulator). In IoT front-end modules, the chip also houses the antenna(s).
What Is the Purpose of an RF IoT Front End Module?
The purpose of an RF IoT front-end module is to amplify the RF signal for the respective wireless protocol and reduce noise, all while consuming very little power.
What Is the Difference Between a Front-End and Back-End Module?
IoT front-end modules sit near or house the antenna, while back-end modules are a step or layer behind the front-end module in the signal transmission stack. These back-end modules usually perform baseband processing, convert analog signals to digital signals (and vice versa), and house subsystem controls.
