At Mobility Field Day 4, we heard from a few companies which are working hard to extend the capabilities of their AP’s well past only serving traditional 802.11 clients.
Mist Systems, a Juniper Company, was one such presenter, and they might have a fantastic new platform with their latest hardware, the AP43.

The idea is simple. Most campuses have AP’s covering their entire environment. In many large environments, they share that ceiling space with other types of sensors or networks. These overlay networks may include building and security sensors, Zigbee control of lights or door locks, and test sensor networks.

In many ways, Mist has been a bit ahead of this curve. Their AP’s already included an IoT port, which enabled triggering devices like door locks or sensing through a variety of GPIO sensors.

Their new AP43 is a dual 5Ghz capable 802.11ax access point. It includes 802.3bz NBASE-T port to ensure the network port never becomes a bottleneck. That port also includes 802.3bt power capabilities so that it can pass power out of its secondary port, enabling it to daisy chain any 802.3af network device. The obvious candidate here is the BT11, Mist’s BLE sensor.

Further, each AP43 includes built-in sensors to provide temperature, humidity, barometric pressure, and angle/orientation. The inclusion of these sensors come with some unique engineering challenges. If Mist is successful in getting them to work appropriately, it could be a game-changer.

The biggest challenge when considering environment monitoring on an access point is heat. Anyone who has ever touched an AP that has been on for a while knows it can be hot. Thanks to the first law of thermodynamics, we know that all energy consumed by the AP that doesn’t get radiated as RF is instead transformed to heat. But that heat output isn’t consistent. It will vary based on the transmitter duty cycle or CPU load of the AP.

Additionally, that heat creates a micro-climate around the AP, which will lower the humidity percentage since warm air holds more water than cool air. Warm air is also less dense, which may affect the barometric pressure sensor.

The humidity/heat problem is further exacerbated by the fact that all water in the air is absorbing a small amount of the radiated RF power.

Finally, the ceiling can be many degrees warmer than in the same room at desk level.
These are challenges that I am sure Mist has taken into account, and the fact that they can work through them is impressive. Having environmental reporting built into the AP could make for a fantastic use case for building managers.

Moving down the list, the barometric pressure and orientation/angle sensor have some compelling use cases. By comparing atmospheric pressure among AP neighbors, Mist should be able to tell which AP’s are on the same floor in multi-floor buildings. This information could significantly impact 802.11k neighbor reports. By excluding AP’s which may be heard by the AP, but are obviously on a different floor, the chances of a client choosing a better roam candidate increases.

By comparing atmospheric pressure among AP neighbors, Mist should be able to tell which AP’s are on the same floor in multi-floor buildings. This information could significantly impact 802.11k neighbor reports.

Finally, the angle sensor can help identify AP’s mounted on a wall versus a ceiling. With that information and Mist’s ML backend, it should be able to better locate clients in RTLS environments.

These new sensors extend the AP capabilities well past the traditional use cases. Can Mist pull off the environmental monitoring? Can they adjust their neighbor report automatically based on elevation? I’m excited to play with these features in the future and get to the bottom of these answers and more.

Either way, it is clear that Mist has built the AP43 as a platform they can innovate with and I’m excited to see where they take it.

Take a look and tell me what you think: