Cisco Systems 2700 manual Accuracy, Software Requirements, Hardware Requirements

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.

Table 1	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

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.

Cisco 2700 Series Wireless Location Appliance Deployment Guide

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