Cisco Cisco Aironet 1524 Lightweight Outdoor Mesh Access Point
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Mobile Access Router and Mesh Networks Design Guide
OL-11823-01
Using the MAR3200 in Mobile Environments
Using the MAR3200 in Mobile Environments
This section describes how the MAR is used in mobile environments.
WMIC Roaming Algorithm
There are four conditions that will trigger the WMIC to start scanning for a better root bridge or access
point:
point:
•
The loss of eight consecutive beacons
•
A shift in the data rate
•
The maximum data retry count is exceeded (the default value is 64 on the WMIC)
•
A measured period of time of a drop in the signal strength threshold
Only the last two items in this list are configurable using the packet retries command and mobile
station period X threshold Y (in dBm); the remainder are hard-coded. These commands are issued
under the dot11 interface.
station period X threshold Y (in dBm); the remainder are hard-coded. These commands are issued
under the dot11 interface.
If a client starts scanning because of a loss of eight consecutive beacons, the message “Too many missed
beacons” is displayed on the console. In this case, the WMIC is acting as a Universal Bridge Client,
much like any other wireless client in its behavior.
beacons” is displayed on the console. In this case, the WMIC is acting as a Universal Bridge Client,
much like any other wireless client in its behavior.
An additional triggering mechanism, mobile station (if mobile station is configured), is not periodic but
does have two variables: period and threshold.
does have two variables: period and threshold.
The mobile station algorithm evaluates two variables: data rate shift and signal strength and responds as
follows:
follows:
•
If the driver does a long term down shift in the transmit rate for packets to the parent, the WMIC
initiates a scan for a new parent (no more than once every configured period).
initiates a scan for a new parent (no more than once every configured period).
•
If the signal strength (threshold) drops below a configurable level, the WMIC scans for a new parent
(no more than once every configured period).
(no more than once every configured period).
The data-rate shift can be displayed using the debug dot11 dot11Radio 0 trace print rates command.
However, this will not show the actual data rate shift algorithm in action, only the changes in data rate.
This determines the time period to scan, depending on how much the data rate was decreased.
However, this will not show the actual data rate shift algorithm in action, only the changes in data rate.
This determines the time period to scan, depending on how much the data rate was decreased.
The period should be set depending on the application. Default is 20 seconds. This delay period prevents
the WMIC from constantly scanning for a better parent if, for example, the threshold is below the
configured value.
the WMIC from constantly scanning for a better parent if, for example, the threshold is below the
configured value.
CCKM key
management
management
Set up and enable WEP and enable
CCKM authentication
CCKM authentication
Set up and enable WEP and enable
CCKM authentication, configure the
root device to interact with your WDS
device, and add the root device to your
authentication server as a client device
CCKM authentication, configure the
root device to interact with your WDS
device, and add the root device to your
authentication server as a client device
WPA key
management
management
Set up and enable WEP and enable
WPA authentication
WPA authentication
Set up and enable WEP and enable
WPA authentication
WPA authentication
Table 6
Client and Bridge Security Settings (continued)