Casey
O'Grady
It’s hard to imagine a world before
smartphones. What used to be a futuristic plot on the Jetson’s is now the reality we
live in. As we strive to connect more of our lives, homes and buildings, the design
complexities can rapidly escalate. Learning wireless protocols and acquiring
radio-frequency (RF) design experience can be an overwhelming venture. Add network
security and power budgets into the mix, and you’ll quickly feel like a freshman
walking into their first college lecture.
Take a home or building security
system as an example. There are door and window sensors, motion detectors, smoke
detectors, smart locks, and a security panel that need to connect wirelessly, comply
with local regulatory requirements and perform with high accuracy at the lowest
power consumption. That’s a big task to execute. But I have a few simple pointers
that can help you avoid the headache and design with ease.
1. Select a Platform That Supports Multiple Wireless Protocols.
A building security system may have multiple RF technologies and will often leverage multiple protocols. These are the leading players for building security applications:
You can implement building security systems using any one of these technologies or a combination of several of them. Thus, it’s a good idea to choose a hardware platform that can address multiple protocols and give you software flexibility
depending on your application.
2. Address Network Security.
Security is a key concern, especially in building security systems. Consumers want to know that their personal information will remain protected. When choosing a wireless platform, security must be at the forefront
of your decision. Let’s take a look at the security measures of the wireless protocols I just reviewed:
- In Sub 1-GHz, designers can implement the Advanced Encryption Standard (AES) algorithm and authentication, as well as message integrity to ensure network security.
- Bluetooth Low Energy also leverages AES hardware encryption. The Bluetooth low energy 4.2 specification implemented increased security to prevent man-in-the-middle attacks and correct pairing vulnerabilities.
- Zigbee has defined procedures to ensure the secure request and exchange of keys, and uses install codes to eliminate the use of well-known keys as well as AES encryption.
- Thread implements IP-based security with Datagram Transport Layer Security (DTLS), password-based authentication and AES encryption.
With each of these protocols, it’s important to assess the threats in your system and use security enablers to address these concerns.
3. Seek High Performance and Low Power.
When designing a building security system, you have to take range and power seriously. Extending the battery life of door and window sensors, electronic smart locks, and smoke detectors helps create a positive
experience with the end product. Not only do you have to evaluate a device’s receiver and transmitter current; you must also evaluate the sleep current to ensure maximum battery life.
Likewise, ensuring maximum coverage within a home is paramount. Whether it’s controlling a large number of devices within a mesh network or simply using a smartphone to control one device, it’s imperative that users
can maintain a reliable connection. Output power and sensitivity are the critical parameters you need to determine the achievable range. By leveraging a large link budget, a security system will be able to cover a greater distance within a
home or building.
Conclusion
Designing a
security system can be challenging, especially when it comes to the many
connectivity options, network security and performance. With the flexibility to
support Sub 1-GHz, Bluetooth Low Energy, Zigbee, Thread and dual-band protocols,
TI’s wireless microcontrollers (MCUs) are geared to provide robust and secure
solutions for building security systems.
These powerful devices feature more memory, peripherals, flexibility and processing power, as well as excellent RF performance at extremely low power consumption. As you design a building security system, keep the suggestions above in mind
to unlock the most innovative designs yet.