Designing a building security system with the Sub-1 GHz sensor-to-cloud reference design

Building security systems come in many system topologies, ranging from a simple alarm system to a complicated network of sensors that all report to a main security panel acting as a hub. These systems are either wired or wireless based on their deployment, and when wireless leverage many different types of connectivity to achieve their specific application. Some applications (like security cameras) use Wi-Fi® for a native connection to the cloud, while some smart applications (like door locks) use Bluetooth® low energy in order to connect to phones and tablets. Security systems based on sensor networks, such as smoke detectors, motion detectors, door/window sensors, and glass-break detectors, can benefit from using Sub-1 GHz networks.

Sub-1 GHz technology offers many advantages when designing a building security system, including achieving much longer range and better wall penetration than 2.4 GHz technology. This enables whole building coverage without the need for repeaters and without having to use a complicated mesh network topology. Sub-1 GHz is also very low power, enabling remote sensors to operate for 10 years on a coin-cell battery. This benefit offers system design flexibility, eliminating the need to route wires inside ceilings and walls.

One essential point when designing building security systems is that the communication must be reliable. Sub-1 GHz systems offer high robustness by taking advantage of the Sub-1 GHz frequency band, which is less crowded than other popular bands.

While it is clear that Sub-1 GHz has many key advantages for building security design, often security systems and sensors must have a cloud connection or a smart device interface requiring Wi-Fi and Bluetooth low energy. However, it is very complicated to design a system that sends and receives sensor data over a Sub-1 GHz star network, connects to the cloud, and provides a smart device interface. Thanks to the dual-band capabilities and flexible radio features of the CC1350 wireless microcontroller (MCU) and the Sub-1 GHz Sensor to Cloud solution, you can easily develop products that seamlessly connect to both smart devices and the cloud while still leveraging the benefits of Sub-1 GHz technology.

The Sub-1 GHz sensor-to-cloud solution provides cloud connectivity for sending and receiving sensor data over a long-range Sub-1 GHz star network. The design is based off of the ultra-low power SimpleLink™ CC1310 Sub-1 GHz wireless MCU and the SimpleLink CC1350 dual-band wireless MCU enabling Sub-1 GHz plus Bluetooth low energy. The reference design pre-integrates the TI 15.4-Stack (part of the SimpleLink CC13x0 software development kit), a complete star networking solution. Additionally, the devices and tools are part of TI’s SimpleLink MCU platform, providing a unified software experience across TI’s low-power wired and wireless MCUs. Figure 1 is a high-level system diagram of the reference design.

  

Figure 1: Sub-1 GHz sensor-to-cloud system diagram

The Sub-1 GHz sensor-to-cloud reference design scales to many different applications. For instance, imagine designing a building security system including smoke detectors, motion detectors, door & window sensors, and glass-break detectors covering a whole building, and all communicating with a centralized security panel. The system design requires that consumers view sensor data on the web or a smart device. The solution can help achieve this use case, while supporting a fast time to market and being flexible enough to enable various solution architectures.


Figure 2: Home security system example

As Figure 2 shows, the peripheral sensors (smoke detector, motion detector, door/window sensors and glass-break detectors) all talk to the central security panel over a Sub-1 GHz star network. The security system leverages the long range and wall penetration of Sub-1 GHz to cover the whole building. Additionally, you can place sensors that don’t have access to AC power, like the door and window sensors, remotely; they can run for 10 years on a coin-cell battery. Using the CC13150 dual-band MCU, the smoke detector can connect over Bluetooth low energy to a phone or tablet and send users alerts on their smart device.

These alerts can report battery life or any danger detected, while the smoke detectors communicate to the main security panel over the Sub-1 GHz network. The security panel can collect data from all of the sensors and, using Wi-Fi, connect to the cloud to report to the security company or enable visualization of the data on the web. Users can also update the system firmware by connecting to the panel with Bluetooth low energy or receiving the updates from the cloud. The panel can then push those updates out to the peripherals and update the firmware of each node over the Sub-1 GHz network.

This building security system example is just one use case enabled by TI’s sensor to cloud solution. The gateway architecture is flexible, enabling interfaces to multiple cloud providers. The reference design also comes with two gateway options: one based off SimpleLink Wi-Fi technology running on TI-RTOS and one based off a Linux environment. Finally, the design is based on proven hardware and software from the SimpleLink MCU platform, which will shorten development time and enable quick time to market. Take advantage of the solution and start your design today.

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