New Modules Aim to Bring Wireless Connectivity to Everyday Products

Silicon Labs' mesh-networking modules are intended to ease the development and time to market of BLE, Bluetooth mesh, Zigbee and Thread mesh functionality in lighting, appliances and other products.
Published: October 14, 2019

Semiconductor and Internet of Things (IoT) solutions company Silicon Labs has released two new mesh-networking modules intended to enable companies such as lighting and building-automation manufacturers to integrate Bluetooth Low Energy (BLE), Bluetooth mesh, Zigbee or Thread mesh networks into their products. The Wireless Gecko xGM210L and xGM210P Series 2 modules leverage the company’s Series 2 platform to provide what it says will be greater security and better RF functionality than predecessor technologies.

The company began providing samples and production quantities of the xGM210P module in September 2019, while the xGM210L is expected to be made available later this year. The firm is also selling Wireless Gecko starter kits and Series 2 radio boards. In April 2019, it released its Series 2 system-on-chip (SoC) portfolio targeting line-powered IoT applications. The SoCs have been integrated into the Series 2 modules to provide wireless connectivity and security functionality.

Silicon Labs’ IoT mesh-networking module

The goal of the Series 2 portfolio, the company reports, is to enable IoT innovation by product manufacturers that may not have the lead time or budget required for developing mesh-networking SoCs and related modules, or for handling RF certification. The Series 2 modules are pre-certified, Silicon Labs explains, and can be quickly applied to an existing LED bulb design, or to other commercial or industrial products, without the added cost of RF design, certification and software development. In fact, the firm has been selling IoT products for several years that are intended to make mesh-networking possible with everyday applications, such as smart LED light bulbs, factory-automation systems and heating, ventilation and air-conditioning (HVAC) systems.

Silicon Labs acquired Integration Associates in 2008, which provided the company with a short-range wireless portfolio for smart meters and building automation. The firm next acquired Zigbee technology company Ember in 2012, and then Bluetooth module and software provider Bluegiga in 2015. Silicon Labs gained intellectual property rights for Wi-Fi subsequent to that, and last year it also acquired the smart-home wireless technology Z-Wave.

These days, Silicon Labs provides wireless SoCs, modules and software stacks to enable wireless connectivity, including mesh functionality, to be built into IoT devices. Users can acquire the modules, which come with necessary protocol software and wireless certification, for fast time to market and reduced R&D costs, the company reports, or they can use Silicon Labs’ wireless SoCs as a cost-effective option for high-volume applications, while preserving their investment in software and tools.

Silicon Labs released its Series 1 Wireless Gecko SoCs in 2016, says Ross Sabolcik, the firm’s VP and general manager of industrial and commercial products, and “the family has been very successful for us.” The first products supported multiband and multiprotocol connectivity, including BLE, Thread, Zigbee and proprietary protocols. The company then offered modules targeted for specific applications with multiprotocol or BLE-only products. “We have major market share with lighting, home automation and building automation using those modules,” he says.

The Series 2 SoC, released in April, supports greater security in addition to other enhancements. “We’ve improved receive sensitivity and power consumption,” Sabolcik explains. The modules’ Arm Cortex-M33 core operates at 80 MHz, and the modules include one megabyte of flash memory and 96 kilobytes of RAM—ample memory to run communication stacks and customer applications, according to the company. With the higher RF performance, Sabolcik says, users can achieve long-range BLE applications with a read range of hundreds of meters.

Silicon Labs’ Ross Sabolcik

As IoT devices become more ubiquitous, Silicon Labs has found that manufacturers are seeking more secure solutions. “A trend we’re seeing is customers grappling with how to secure their IoT devices more robustly than they have in the past,” Sabolcik states. Therefore, the Series 2 SoCs and modules integrate a dedicated security core to handle cryptographic operations.

The security upgrades are provided to meet potential vulnerabilities in IoT devices for manufacturers and product users, Sabolcik says. Those upgrades include Secure Debug with lock/unlock, Secure Boot with root of trust and secure loader (real-time location system, or RTLS) technology, differential power analysis counter measures, and a True Random Number Generator (TRNG). One existing security feature is the ability to lock down the application port so that bad actors cannot snoop the code or try to download malicious software. Although that feature offers security, it also poses a challenge.

In the past, Sabolcik says, customers were running into challenges trying to accomplish maintenance, but they were locked out of the application. With the Series 2 modules’ Secure Debug feature, he notes, the product supplier can share a secret key that customers can use to lock the port so that other authorized developers can unlock it to conduct maintenance or lifecycle management. The Secure Boot feature combats attacks in which hackers can try to corrupt the firmware inside a device, and thereby extract secret keys to conduct a broader attack. Secure Boot allows users to protect the data they download to the device by storing it in a dedicated section that requires a secret key to access.

Another security feature, differential power analysis, prevents hackers from viewing a device’s power consumption. In some cases, hackers might attempt to view power consumption on the power pins, and thereby infer what is happening onboard the device. In that way, Sabolcik says, they can extract security keys based on that power analysis. With the Series 2 feature, he adds, the power supply can be scrambled so that it cannot be detected.

By offering both Series 2 modules and SoCs, Sabolcik says, Silicon Labs enables customers to use the pre-certified module with firmware initially, while they have the option to migrate to the SoC as they expand product volumes. “Customers can move seamlessly between using the module to get to market quickly,” he states, “and then later on, when volume ramps up, use the SoC instead of the module.”

Companies that utilize the Gecko modules commonly include LED lighting manufacturers looking to add a wireless module or SoC inside a bulb or ballast. Because temperatures can become high in such an environment, the Series 2 version is designed to manage higher temperatures of up to 125 degrees Celsius (257 degrees Fahrenheit). The Series 2 modules support Zigbee, Thread, BLE and Bluetooth mesh, as well as multiprotocol connectivity, and can be provided in versions that support specific transmission protocols. Each module comes with a built-in Cortex-M33 processor core and up to 125 dBm link budget (transmission gains and losses during the active state).

The Series 1 and 2 products are being used in a wide range of IoT applications, the company reports, including consumer and commercial lighting. One application is lighting fixtures that provide occupancy sensing in an office or industrial setting. The sensors detect motion within range of a light bulb, and the mesh network then forwards that data to the cloud, where specific events can be triggered, such as lighting being turned up or down based on activity within the room.

Companies typically build their mesh systems with a pre-certified Wireless Gecko module, Sabolcik says, which helps improve time to market. They can then migrate to using lower-cost Wireless Gecko SoCs for higher-volume applications. This may be a more affordable option, he notes, since other module companies may not be able or willing to sell their wireless software without the module itself, whereas Silicon Labs provides a choice of both modules and SoCs, along with the necessary wireless software stacks.

The xGM210L module is designed for use with LED lights, with the RF antenna positioned away from the metal shielding at the light bulb’s base. The xGM210P modules are built for a wide range of commercial and industrial applications, including lighting systems requiring a small form-factor solution. While the xGM210L’s power output is +12.5 dBm (optimized for LED applications), the xGM210P’s output power is higher, at +20 dBm.

“We think the improvements we’ve made in radio performance and reduction in power will really enable high-performance communications in these applications,” Sabolcik states. “We think customers are starting to be very concerned about security for their products, so the additional security features will be critical for IoT growth.”