Ruckus Wireless SPoT - Location Based Best Practices Part 2

Building an Accurate Data Map

These days, the RF environment that the network is deployed within is constantly changing; something as minor as the repositioning of a few pieces of furniture, or a person walking through the room, can change radio propagation from one moment to the next. To combat this, system intelligence in the Ruckus SPoT algorithm does its best to reconcile the fluctuations whilst performing reliable location estimates.

But it's no good having a fantastically intelligent algorithm, if the calibration isn't there, so what are the best practices to ensure that goes off without a hitch?

  • use a calibration device with the same characteristics as the devices that you are most interested in tracking. It's no good using a laptop to calibrate if your business and it's customers mainly use mobile phones and tablets. Saying that, the location algorithms that SPoT possesses will actually allow it to position devices with different transmit characteristics than those used within calibration, assuming that the dB difference is consistent throughout the reference points
  • increasing the density of anchor points in the calibration map will only increase the accuracy of the calibration. Anchor point distance can range between 3-8m, depending on how ambitious you're feeling

Differentiating Calibration Points

By placing anchor points in as many differing scenarios and environments as possible, you are thoroughly increasing the estimation accuracy:

  • Avoid straight lines and hallways
  • Large open spaces may need more AP's (even if density is low, extra AP's may still be required in order to provide at least 3 received signals for accurate location estimates)
  • Mount some AP's near the edges (this provides some form of perimeter guideline)
  • VoIP designs often work well (the same principles apply when designing for VoIP as when designing for accurate location services)
  • Reality check (use discretion when there are areas where accuracy is of less importance, it's a slippery slope to being left with a deployment that isn't delivering the analytics you so desperately wanted)

Maximizing accuracy with High RSS

Ruckus SpoT functionality follows similar requirements as for VoIP. The below table shows accuracy guidelines for AP density and Signal Strength.

If you're deploying SPoT, and can follow the above density and signal strength goals, then accuracy, and a successful deployment should follow.