Installation guide

Wi-Fi Location-Based Services—Design and Deployment Considerations

OL-11612-01

RFID Tag Considerations

• Access points not on the same channel as the 802.11b asset tag or not RF-adjacent do not initiate

protection mode.

Some asset tags with motion detection can be configured to be almost completely RF silent when assets

are not in motion. They associate and transmit information only when they have something to report (that

is, movement); otherwise, they are “sleeping” for very long periods. The relatively small payload of the

tag along with the number of tags that are in use and their frequency of movement can often mitigate the

impact of protection mechanisms on throughput.

For those designers wishing to avoid the issue altogether in environments that are otherwise 100 percent

802.11g, there are two good ways to accomplish this:

• Consider the use of asset tags with 802.11g client radios such as the new PanGo version 2 LAN

Locator asset tag.

• Use a Layer 2 multicasting 802.11b RFID tag such as the AeroScout T2. Layer 2 multicasting asset

tags that are configured for the same channel as 802.11g access points do not cause the target access

point, adjacent access points, or any detecting access points to initiate protection mode. These types

of asset tags do not associate to access points at all.

Enabling Asset Tag Tracking for L2 Multicasting Asset Tags

Tracking of Layer 2 multicasting asset tags is disabled by default in the location appliance, WLAN

controllers, and WCS. To track such asset tags successfully, follow the steps outlined in the subsections

below.

Note The steps described in this section are necessary only when using AeroScout 802.11 active RFID asset

tags or other L2 asset tags that do not associate to the WLAN infrastructure. These steps are not

necessary when using asset tags that associate/authenticate to the WLAN infrastructure as a full WLAN

client (such as those from PanGo Networks).

Enable Asset Tag Tracking in WLAN Controllers

For Cisco WLAN Controllers, connect to the controller via Telnet, SSH, or the console port and issue

the following commands:

(Cisco Controller) >show rfid config

RFID Tag data Collection......................... Disabled

RFID Tag Auto-Timeout............................ Disabled

RFID Client data Collection...................... Disabled

RFID data timeout................................ 1200 seconds

Note that “RFID Tag data collection” is disabled by default. To enable it, issue the following command:

(Cisco Controller) >config rfid status enable

(cisco Controller) >

(Cisco Controller) >show rfid config

RFID Tag data Collection......................... Enabled

RFID Tag Auto-Timeout............................ Disabled

RFID Client data Collection...................... Disabled

RFID data timeout................................ 1200 seconds

Asset tag data collection is now enabled in the WLAN controller, and asset tag signal strength

information is aggregated and forwarded to the location appliance when the controller is polled.