If you checked out the Bluetooth LE range use case post, you’re well aware of our made-up, engineer/fitness friends who recently started an obstacle course business. If not, here’s a quick synopsis:
The owners of a fitness obstacle course for adults are looking to offer more data for contestants. They want to show people their top speeds, the route they chose, time elapsed, and more. People love data. But first, they need to build a tracking device system. Being electrical engineers, they take a Sunday afternoon to see if they can build this tracking device system themselves. They’ll first need to test out which type of wireless technology to use and maximum range capability for each, and today they’ll be trying out Zigbee (yes - they have unlimited resources, for the sake of the story).
What is the expected ZigBee maximum range in meters from the second-floor antenna?
Antenna: Second floor, block-wall building
Receiver: One meter off the ground in the parking lot (in the hands of one of our buddies)
| ZigBee | |
| TX Antenna Height (m) | 6 |
| TX Power (dBm) | 18 |
| TX Antenna Gain (dB) | 0 |
| Frequency (MHz) | 2400 |
| RX Antenna Height (m) | 1 |
| RX Antenna Gain (dB) | -6 |
| Structure Loss (dB) | 11 |
| Sensitivity (dBm) | -102 |
| Margin (dB) | 20 |
| Range | 291 |
(Note: 11dB structure loss consistent with propagation through an 8" masonry block wall)
With one antenna on the second floor, the expected range for ZigBee is 291 meters. That’s not enough distance to cover all of the obstacle courses that span a few football fields. If they could move the antenna to a more central location, ZigBee could work. For now, they check their other options:
Want to learn about what we're building at Link Labs? Click below to learn about the system with 2594 meters of range using the same assumptions.