Making a case for presence-based security systems. An evolution from security alarm systems to smart buildings. Part 1.

Alviso (Crankk.io)
4 min readDec 26, 2018

Let me start with a comparison of conventional security alarm systems and smart homes and express that there’s a disconnect between the two and not an evolutionary path let alone an upgrade path.

Conventional security alarm systems have a few distinctive traits

  • Armed and disarmed state
  • Motion sensors
  • Door and window sensors
  • Local alarm with sound, optional remote notification to security service or to the owner
  • Separate camera system with recording

Smart home security on the other hand leverages modern IoT technology

  • Security is just one of the goals, home automation is equally pronounced
  • Motion and sometimes person detection cameras (wireless)
  • Door and window sensors (wireless)
  • Expressly cloud based services
  • Mobile App configuration and notification

In both cases if you want to take advantage of remote notification you need to rely on a 3rd party service or cloud service. While smart homes are a compelling idea the heavy reliance on alarm rules and decisions stored and made in the cloud makes it more difficult for the user to understand what’s going on and trust that those decisions are the right ones and according to their expectations.

I propose that there should be a more evolutionary path from conventional security alarm systems to smart homes that keeps it closer to the user’s understanding and also provides an actual hardware upgrade path as well, meaning that you can keep an existing system with all of its hardware components and achieve smart home features and capabilities at the same time.

So how do we turn an existing security alarm system into a smart home system?

  • Make use of existing motion detectors and window/door sensors. In most systems those are wired and their signals can be used by integrating a small “bridge” box in between the sensor and the central unit. The most convenient place for these is right beside the sensor. Power is also available since those sensors also use power so it is delivered to them anyway on an existing wire.
  • Another option is to upgrade the motion detectors with equivalent ones that also have the necessary electronics for Wi-Fi connectivity and bluetooth detection. The extra investment needed is still pretty low.
  • These bridge boxes or upgraded motion detectors are Wi-Fi (mesh) and bluetooth enabled so they connect to the cloud easily and able to detect the presence of bluetooth beacons.
  • Authorized or allowed presence in a room is defined by the presence of a bluetooth beacon. These are small wearable devices that run on battery for months without needing a recharge or battery replacement. People can have those with them in a form of a bracelet, keycard or as a keychain token.

When the motion sensor or door sensor triggers, the detection event will either be blocked or let thru depending on a quick check by the extra electronics whether the person present is actually allowed to be there. If not or a presence of a bluetooth beacon signal is not detected the alarm signal will be forwarded to the central unit of the security system which can trigger depending on whether it’s actually armed or not. But independently of the armed or disarmed status of the legacy alarm system all information regarding the event will be sent to the cloud that can make its independent decision how to react, whether to send a notification to your app or just provide it as information.

These small bluetooth beacons can also be worn by your pets in your home giving you a better option of leaving the security system armed while only the pets are home.

There are of course some nuances as to how to adapt to each situation and environment. Is it a home or an office, do people have an option to carry a wearable device with them all the time.

One interesting feature of these bluetooth beacons is that they are by themselves motion sensitive, so situations when someone leaves it on a desk by accident that would prevent the secutity system from triggering, can be easily avoided.

For pets the size and weight of the device is much more suitable than those of a GPS tracker. This will not track pets outside the property but is very appropriate to tell what room they are in or are they just near the house somewhere outside. How much and when they are moving is also readily available information.

For people in an office or shop floor carrying a bluetooth tag is most likely not a nuisance since they already carry a keycard or company badge most of the time.

For people in the home it may be more inconvenient to carry something with them all the time. For this case a bracelet is probably the best option.

What’s next?

Once you have these unobtrusive sensors in your building it opens up other use cases as well.

  • Door / gate access control with bluetooth tags. Motion sensing, orientation detection and integrated button combined with enctrypted bluetooth communication opens up exciting features toward multi factor authentication.
  • Asset tracking / asset motion detection
  • Ad-hoc, personalized emergency evacuation plan

Part 2. will discuss these possibilities and Part 3. will go deeper into technical implementation.

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