Installation guide

72
Wi-Fi Location-Based Services—Design and Deployment Considerations
OL-11612-01
Deployment Best Practices
Figure 49 Example of Suggested Calibration Locations
To complete the calibration data collection and save the sample set, 150 client location to access point
measurements must be recorded per band from 50 distinct locations in the target environment. In some
cases, it may be noticed that although 150 client location to access point measurements have been
collected, not all areas have been visited (white areas are present on the map). If this occurs, it is
recommended that the remaining areas be visited and measurements collected. Doing so provides the
system with a more complete representation of the path loss characteristics seen throughout the
environment.
To reduce the amount of effort required in calibration data collection for both 2.4 GHz and 5GHz clients,
it is suggested that the calibration procedure be performed with a recommended dual band 802.11a/bg
wireless client adapter such as the Cisco CB21AG. Using a dual band client allows calibration samples
to be taken for both 2.4 GHz and 5 GHz simultaneously, reducing the overall calibration effort by 50
percent. In addition, for optimum ease of use and visibility during the data collection procedure, a laptop
computer with a large clear and bright screen is recommended as a calibration client, especially in areas
of bright ambient light.
When a sufficient amount of data has been collected and data collection is complete, the data needs to
be processed and the model calibrated. This is performed via Monitor > Maps > RF Calibration Model
> model name > Calibrate. The actual calibration of the model using the results of the data collection
can take some time because the system performs many mathematical calculations to derive the best path
loss model for the environment. After the model has been successfully calibrated, you can examine its
performance using the Location Inspector (see Inspecting Location Quality, page 76) and subsequently
apply the calibration model to one or more floors in the network designs using Monitor > Maps > RF
Calibration Model > model name > Apply to Floors.