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Cisco IOS Software Configuration Guide for Cisco Aironet Access Points
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Chapter6 Configuring Radio Settings
Enabling and Disabling Gratuitous Probe Response
Enabling and Disabling Gratuitous Probe Response
Gratuitous Probe Response (GPR) aids in conserving battery power in dual mode phones that support
cellular and WLAN modes of operation. GPR is available on 5-Ghz radios and is disabled by default.
You can configure two GPR settings:
•Period—This setting determines the time between GPR transmissions in Kusec (or milliseconds)
intervals from 10 to 255 (similar to the beacon period)
•Speed—The speed is the data rate used to transmit the GPR
Selecting a longer period reduces the amount of RF bandwidth consumed by the GPR with the possibility
of shorter battery life. Selecting higher transmission speeds also reduces the amount of bandwidth
consumed but at the expense of a smaller cell size.
Beginning in privileged EXEC mode, follow these steps to enable GPR and set its parameters:
The optional parameters can be configured independently or combined when you do not want to use the
defaults, as shown in the following examples:
(config-if)# probe-response gratuitous period 30
(config-if)# probe-response gratuitous speed 12.0
(config-if)# probe-response gratuitous period 30 speed 12.0
Use the no form of the command to disable the GPR feature.
Disabling and Enabling Aironet Extensions
By default, the wireless device uses Cisco Aironet 802.11 extensions to detect the capabilities of Cisco
Aironet client devices and to support features that require specific interaction between the wireless
device and associated client devices. Aironet extensions must be enabled to support these features:
•Load balancing—The wireless device uses Aironet extensions to direct client devices to an access
point that provides the best connection to the network based on factors such as number of users, bit
error rates, and signal strength.
•Message Integrity Check (MIC)—MIC is an additional WEP security feature that prevents attacks
on encrypted packets called bit-flip attacks. The MIC, implemented on both the wireless device and
all associated client devices, adds a few bytes to each packet to make the packets tamper-proof.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface dot11radio {1}slot/port Enter interface configuration mode for the 5-GHz radio
interface.
Step3 probe-response gratuitous
{period | speed}
Enable the Gratuitous Probe Response feature using default
period (10 Kusec) and speed (6.0 Mbps).
Step4 period Kusec (Optional) Enter a value from 10 to 255. The default value is 10
Step5 speed
{[6.0] [9.0] [12.0] [18.0] [24.0]
[36.0] [48.0 ] [54.0] }
(Optional) Sets the response speed in Mbps. The default value
is 6.0.
Step6 end Return to privileged EXEC mode.
Step7 copy running-config startup-config (Optional) Save your entries in the configuration file.