Location-Based Services Overview

Figure 4

System Architecture

Access points can detect devices both on the channels where they service clients and on all other channels by periodically scanning, while still providing uninterrupted data access to their wireless clients. The gathered raw location data is then forwarded from each access point upstream to its controller. The location appliance polls controllers via SNMP for this raw location information.

To understand this gathered device information, the location appliance works with WCS to determine access point and device locations, based on input network diagrams that consist of floor maps. The visual front-end of the location appliance is provided through WCS where either a single device's location or an entire floor's devices may be depicted simultaneously. All device details and specific historical location information is accessed through WCS as well.

Using Cisco's Centralized wireless LAN architecture and location-based services, administrators can determine the location of any 802.11-based device, as well as the specific type of each device. Clients, rogue access points, rogue clients, and asset tags can all be identified and located by the system.

Clients are all devices associated with controller-based, lightweight access points on your network.

Rogue access point is any access point that is determined not to be part of the wireless LAN that detected it. This consists of all non-system access points within earshot of lightweight access points, including those on the wired network or those on another wired network (such as a neighbor's access point).

Because all lightweight access points hash a portion of the beacon frame with a special key, even spoofed infrastructure access points are identified as rogue access points, rather than mistakenly indicated to be legitimate access points flagged in WCS as spoof access points.

Cisco 2700 Series Wireless Location Appliance Deployment Guide

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