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Cisco 2700 Series Wireless Location Appliance Deployment Guide
OL-8478-01
Calibration is the process whereby sample signal strength measurements are physically taken in the
actual environments in which you wish to perform location tracking as inputs to tune the location
tracking rather than using the canned or simulated environment’s inputs. Calibration is performed on a
per-floor basis with a wireless laptop using RSSI measurements.
The goal of the calibration process is to refine location accuracy to be within the specifications (10 m,
90%). The calibration is done by taking site specific measurements into account and narrowing the delta
between the actual and the predicted location coordinates of a tracked device. The calibration process is
complete when the actual and predicted location coordinates converge. On a per-floor basis, a wireless
laptop takes RSSI measurements. The calibration wizard, embedded in the WCS version of the product,
is launched from the laptop and guides the user through the calibration process.
Accuracy
Because location fidelity is statistical, the location coordinates can be either more or less accurate than
10 meters the other 10% of the time. The location coordinates that fall into this other 10% are known as
outliers. Making adjustments to the deployments of access points to provide more optimal placement, in
addition to performing a calibration, can sometimes yield more accurate results; however, the results are
very dependent on environment and deployment.
Software Requirements
Access points and controllers must be installed with a version of WCS using embedded location.
Expansion licenses are available if greater scale is necessary. Visit the following location for more WCS
SKUs:
http://wwwincisco.com/dsw/wnbu/products/wlm/cwcs/
Hardware Requirements
Because the location appliance participates in a Lightweight Access Point Protocols (LWAPP)
architecture, this guide assumes the user already has or is in process of putting an LWAPP- capable
wireless LAN in place. Both an explanation of the various LWAPP components you can use to do
location tracking as well as a hardware compatibility matrix is provided to ensure all required
LWAPP-compatible infrastructure is in place to support location tracking.
Table1 WCS Versions
Part Number Description
AIR-LOC-2700-L-K9 Cisco wireless location appliances
AIR-WCS-LL-1.0-K9 Cisco WCS with location v1.0 with up to 50
Cisco Aironet 1000 series access points running Linux
AIR-WCS-WL-1.0-K9 Cisco WCS with location v1.0 with up to 50 Cisco Aironet 1000
series access points running Windows 2000/2003 server