You can configure two parameters that affect client location calculations:
Radio measurement requests
Location calibration
These parameters are supported in Cisco Client
Extensions (CCX) v2 and later releases are designed to enhance location accuracy and
timeliness for participating CCX clients.
For the location features to operate properly, the access points must be configured for normal, monitor, or FlexConnect mode. However, for FlexConnect mode, the access point must be connected to the controller.
When you enable the radio measurements requests feature, lightweight access points issue broadcast radio measurement request messages to clients running CCXv2 or later releases. The access points transmit these messages for every SSID over each enabled radio interface at a configured interval. In the process of performing 802.11 radio measurements, CCX clients send 802.11 broadcast probe requests on all the channels specified in the measurement request. The Cisco Location Appliance uses the uplink measurements based on these requests received at the access points to quickly and accurately calculate the client location. You do not need to specify on which channels the clients are to measure. The controller, access point, and client automatically determine which channels to use.
The radio measurement feature enables the controller to also obtain information on the radio environment from the client’s perspective (rather than from just that of the access point). In this case, the access points issue unicast radio measurement requests to a particular CCXv4 or v5 client. The client then sends various measurement reports back to the access point and onto the controller. These reports include information about the radio environment and data used to interpret the location of the clients. To prevent the access points and controller from being overwhelmed by radio measurement requests and reports, only two clients per access point and up to 20 clients per controller are supported. You can view the status of radio measurement requests for a particular access point or client as well as radio measurement reports for a particular client from the controller CLI.
The controller software improves the ability of the mobility services engine to accurately interpret the location of a device through a CCXv4 feature called location-based services. The controller issues a path-loss request to a particular CCXv4 or v5 client. If the client chooses to respond, it sends a path-loss measurement report to the controller. These reports contain the channel and transmit power of the client.
Note
Non-CCX and CCXv1 clients ignore the CCX measurement requests and do not participate in the radio measurement activity.
Location Calibration
For CCX clients that need to be tracked more closely (for example, when a client calibration is performed), the controller can be configured to command the access point to send unicast measurement requests to these clients at a configured interval and whenever a CCX client roams to a new access point. These unicast requests can be sent out more often to these specific CCX clients than the broadcast measurement requests, which are sent to all clients. When location calibration is configured for non-CCX and CCXv1 clients, the clients are forced to disassociate at a specified interval to generate location measurements.
Configuring CCX Radio Management
Configuring CCX Radio Management (GUI)
Step 1
Choose Wireless > 802.11a/n or 802.11b/g/n > Network to open the 802.11a (or 802.11b/g) Global Parameters page.
Step 2
Under CCX Location Measurement, select the Mode check box to globally enable CCX radio management. This parameter causes the access points connected to this controller to issue broadcast radio measurement requests to clients running CCX v2 or later releases. The default value is disabled (or unselected).
Step 3
If you selected the Mode check box in the previous step, enter a value in the Interval text box to specify how often the access points are to issue the broadcast radio measurement requests.
To enable CCX radio management for a particular access point, you must enable access point customization, which can be done only through the controller CLI.
Step 7
If desired, repeat this procedure for the other radio band (802.11a or 802.11b/g).
Configuring CCX Radio Management (CLI)
Step 1
Globally enable CCX radio management by entering this command:
The range for the interval_seconds parameter is 60 to 32400 seconds, and the default value is 60 seconds. This command causes all access points connected to this controller in the 802.11a or 802.11b/g network to issue broadcast radio measurement requests to clients running CCXv2 or later releases.
Step 2
Enable access point customization by entering these commands:
config advanced {802.11a | 802.11b} ccx customize Cisco_AP {on | off}This command enables or disables CCX radio management features for a particular access point in the 802.11a or 802.11b/g network.
config advanced {802.11a | 802.11b} ccx location-meas apCisco_APenableinterval_secondsThe range for the interval_seconds parameter is 60 to 32400 seconds, and the default value is 60 seconds. This command causes a particular access point in the 802.11a or 802.11b/g network to issue broadcast radio measurement requests to clients running CCXv2 or higher.
Step 3
Enable or disable location calibration for a particular client by entering this command:
You can configure up to five clients per controller for location calibration.
Step 4
Save your settings by entering this command:save config
Viewing CCX Radio Management Information (CLI)
To see the CCX broadcast location measurement request configuration for all access points connected to this controller in the 802.11a or 802.11b/g network, enter this command:
show advanced {802.11a | 802.11b} ccxglobal
To see the CCX broadcast location measurement request configuration for a particular access point in the 802.11a or 802.11b/g network, enter this command:
show advanced {802.11a | 802.11b} ccx apCisco_AP
To see the status of radio measurement requests for a particular access point, enter this command:
show ap ccx rmCisco_APstatusInformation similar to the following appears:
A Radio
Beacon Request................................. Enabled
Channel Load Request........................... Enabled
Frame Request.................................. Disabled
Noise Histogram Request........................ Disabled
Path Loss Request.............................. Disabled
Interval....................................... 60
Iteration...................................... 5
B Radio
Beacon Request................................. Disabled
Channel Load Request........................... Enabled
Frame Request.................................. Disabled
Noise Histogram Request........................ Enabled
Path Loss Request.............................. Disabled
Interval....................................... 60
Iteration................................... 5
To see the status of radio measurement requests for a particular client, enter this command:
show client ccx rmclient_macstatusInformation similar to the following appears:
To see radio measurement reports for a particular client, enter these commands:
show client ccx rmclient_macreport beacon—Shows the beacon report for the specified client.
show client ccx rmclient_macreport chan-load—Shows the channel-load report for the specified client.
show client ccx rmclient_macreport noise-hist—Shows the noise-histogram report for the specified client.
show client ccx rmclient_macreport frame—Shows the frame report for the specified client.
To see the clients configured for location calibration, enter this command:
show client location-calibration summary
To see the RSSI reported for both antennas on each access point that heard the client, enter this command:
show client detailclient_mac
Debugging CCX Radio Management Issues (CLI)
To debug CCX broadcast measurement request activity, enter this command:
debug airewave-director message {enable | disable}
To debug client location calibration activity, enter this command:
debug ccxrm [all | error | warning | message | packet | detail {enable | disable}]
The CCX radio measurement report packets are encapsulated in Internet Access Point Protocol (IAPP) packets. Therefore, if the previous debug ccxrm command does not provide any debugs, enter this command to provide debugs at the IAPP level:
debug iapp error {enable | disable}
To debug the output for forwarded probes and their included RSSI for both antennas, enter this command:
debug dot11 load-balancing