Cisco 2700 Series Wireless Location Appliance Deployment Guide This document provides configuration and deployment guidelines as well as troubleshooting tips and answers to frequently asked technical questions for those adding the Cisco 2700 Series Wireless Location Appliance (hereafter referred to as the location appliance) (Figure 1) to a Cisco wireless LAN network. The existing installation and configuration guides for this appliance are available at the following location: http://www.cisco.
lightweight access points. This appliance tracks any Wi-Fi device, including Wi-Fi clients, standards-based Wi-Fi active RFID tags, rogue access points, and clients. It was designed with the following requirements in mind: • Manageability—The same browser-based interface that is used for the Cisco WCS is also used for the appliance.
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 following Cisco wireless LAN controllers are available.
Figure 2 Note Location Determination To add the location appliance, the WCS version with location must be installed. You cannot add the location appliance to the WCS base version. Additional Functionality with Location Appliance Figure 3 illustrates the scale and variety of classes of devices that can be tracked by the location appliance. You can narrow the search parameters if you are interested only in a subset of devices.
System Architecture Figure 3 Scale and Variety of Devices System Architecture The location appliance integrates with Cisco's centralized wireless LAN architecture. The appliance sits out of the data path of the wireless LAN, working with both the WCS and the controllers to track device locations (see Figure 4).
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.
Deployment and Design Requirements Rogue clients are simply all client devices that are associated to rogue access points. Asset tags are any vendors' 802.11-based RF ID tags within range of infrastructure access points. Deployment and Design Requirements Consider the type of devices involved and how many devices will be tracked. Tracking of any of the four device types can be configured.
Deployment and Design Requirements • AIR-ANT-5145V-R • AIR-ANT-5160V-R Access Point Placement To determine the optimum location of all devices in the wireless LAN coverage areas, you need to consider the access point density and location. Ensure that no fewer than 3 access points, and preferably 4 or 5, provide coverage to every area where device location is required. The more access points that detect a device, the better.
Deployment and Design Requirements Figure 6 3. Improved Location Accuracy by Increasing Density In long and narrow coverage areas, refrain from placing access points in a straight line. Instead, attempt to stagger them such that each access point is more likely to provide a more unique snapshot of device location (see Figure 7).
Deployment and Design Requirements Figure 8 5. Improved Location Accuracy by Staggering Around Perimeter Designing a location-aware wireless LAN, while planning for voice as well, is better done with a few things in mind. Most current wireless handsets support only 802.11b, which only offers three non-overlapping channels. Therefore, wireless LANs designed for telephony tend to be less dense than those planned to carry data.
Deployment and Design Requirements the buildings that comprise that campus, and the floors of each building constitute a single network design. The location appliance is set to poll the controllers in that network, as well as be configured to synchronize with that specific network design, in order to track devices in that environment. The concept and steps to perform synchronization between WCS and the location appliance is explained in “Importing the Location Appliance into WCS, page 20.
Deployment and Design Requirements Step 6 Check to enable the Maintain Aspect Ratio check box. Enabling this check box causes the horizontal span of the campus to be 5000 feet and adjusts the vertical span according to the image file’s aspect ratio. Adjusting either the horizontal or vertical span changes the other field in accordance with the image ratio. You should uncheck the Maintain Aspect Ratio check box if you want to override this automatic adjustment.
Deployment and Design Requirements Figure 12 Step 12 WCS is then returned to the campus image with the newly created building highlighted in a green box.Click the green box (see Figure 13). Figure 13 Step 13 Repositioning Building Highlighted in Blue Newly Created Building Highlighted in Green To create a building without a campus, choose New Building and click Go.
Deployment and Design Requirements Step 14 Enter the building’s name, contact information, number of floors and basements, and dimension information. Click OK. WCS is returned to the Monitor > Maps window. Step 15 Click the hyperlink associated with the newly created building. Step 16 On the Monitor > Maps > [Campus Name] > [Building Name] window, go to the drop-down menu and choose New Floor Area. Click Go.
Deployment and Design Requirements Step 21 At the new floor’s image window (Monitor > Maps > [CampusName] > [BuildingName] > [FloorName]), go to the drop-down menu on the upper right and choose Add Access Points. Click Go. Step 22 All access points that are connected to controllers, which WCS is configured to manage and which have yet to be added to another floor map, are displayed.
Deployment and Design Requirements Creating and Applying Calibration Models If the provided RF models do not sufficiently characterize the floor layout, you can create a calibration model that is applied to the floor and better represents the attenuation characteristics of that floor. In environments where many floors share common attenuation characteristics (such as in a library), one calibration model can be created and then applied to all similar floors.
Deployment and Design Requirements Step 7 When the chosen floor map and access point locations are presented, a grid of dots indicates the locations where data collection for calibration is performed. Using these locations as guidelines, position a wireless device in a known location on the floor. Click on the map to position the red crosshairs, indicate where the device should be located, and click Save (see Figure 17).
Configuring the Location Appliance Step 10 When all the raw data collection has been performed, the model must be compiled to allow WCS and the location appliance to use the data for the understanding of RF attenuation characteristics. To compute the collected data points, choose Calibrate from the drop-down menu and click Go.
Configuring the Location Appliance #service network restart 5. Verify that the new IP addressing works properly and that the location appliance has connectivity back to the WCS by pinging the WCS’ IP address. #ping [IP_Address] If IP connectivity is verified between the location appliance and WCS, the location appliance is ready to be imported into WCS. Importing the Location Appliance into WCS To import a location appliance into WCS, follow the steps below. 1. Navigate to Locate > Location Servers.
Configuring the Location Appliance Figure 19 Synchronizing Controllers Step 17 If the network diagram is properly synchronized, two green arrows appear under the Sync. Status column for each diagram. After synchronizing with the network diagram, all floor maps and access point placements associated with that diagram are copied over to the location appliance; therefore, when the location appliance is set to synchronize with the diagram’s controllers, it can decipher where the devices are located.
Location Appliance Maintenance Step 2 On the left choose Administration and then click Polling Parameters. Step 3 Click to check the check boxes to the left of each desired polling parameter. Adjust the intervals if necessary and click Save. Note These settings govern how frequently the location appliance collects device information for the controller from the access points.
Troubleshooting Tips Q & A Restoring the Location Appliance To restore a previously made backup, navigate to Locate > Location Servers and click the hyperlink of the location appliance to be restored. Select the file to be restored from the drop-down menu and click Submit. Note Backups do not include any IP addressing information. Clearing the Location Appliance Configuration Clearing the location appliance configuration removes all setting and location information.
Troubleshooting Tips Q & A A. By default, the location appliance polls controllers for device information every 5-15 minutes, depending on device type. The polling interval can be altered, but if you have not waited for at least this polling interval, devices may not be visible on the map. Q. Why can’t I see tags? A. Ensure that RFID tag tracking is enabled in each controller. In WCS, enable tag polling within the location appliance settings and make sure Show 802.
Troubleshooting Tips Q & A A. When searching for a client or tag, WCS searches in all available location appliances. WCS reports the floor on which the tag is found, and history may show that it has been moving across campuses regardless of which controller the client was associated with. Frequently Asked Technical Questions Other frequently asked general questions are on the Cisco Wireless Appliance home page (http://www.cisco.com/en/US/products/ps6386/products_qanda_item0900aecd8029371a.
Troubleshooting Tips Q & A A. The network load from location traffic depends on a number of factors: – how many devices are present in a given system – how many controllers are present – what information the location appliance is configured to poll for – how frequently polling occurs Network load associated with the location appliance should not be substantial and is generally not a cause for concern.
Troubleshooting Tips Q & A Q. How long do WiFi tags last? A. Tag battery life is a function of specific device battery longevity, as well as how often they beacon or blink. The tags can last anywhere from 100 days to a year or even longer. Some manufacturers advertise that they can last 3-5 years, but it is dependent on the beacon rate. Q. What is the cost of WiFi tags? A. Contact a tag manufacturer since Cisco does not manufacture or resell tags. Also, tag prices are variable and depend on volume.
Troubleshooting Tips Q & A Cisco 2700 Series Wireless Location Appliance Deployment Guide 28 OL-8478-01
