User's Manual

Tsunami MP.11 2454-R, 5054-R, and 5054-R-LR Installation and Management
Chapter 5. Using the Web Interface 53
Click Edit Table Entries to make changes; enter your changes and click OK.
Note that an SU may roam from one BSU with a bandwidth setting to another BSU with a different bandwidth
setting. Since in this case more channels need to be scanned than with only one channel bandwidth setting, it is
important that the channel priority list mentioned above is properly used to limit scanning time.
When Scanning Across Bandwidth on the SU is enabled (see “Configure Interface Settings”
on page 57), the
SU supports bandwidth selection of the communications channel of either 20 MHz, 10 MHz, or 5 MHz. This allows
the BSUs in the network to be set to different bandwidths while an SU can still roam from one BSU to the next,
because it will not only scan other frequencies (when the signal level or quality are lower than the threshold) but it
will also switch to other bandwidths to find a BSU that may be on another bandwidth than its current one.
During roaming, the SU will start scanning first the channels on its current
bandwidth from the “Active” channel list
provided by the BSU in order to find a BSU to register, since that is the most likely setting for other BSUs in the
network. If the SU cannot find an acceptable roaming candidate, it will switch bandwidth and start scanning
channels on that corresponding bandwidth from the “Active” channel list provided by the BSU. The process is
repeated until the SU finds an appropriate BSU to register.
In the example above, an SU whose current bandwidth is 20 MHz will start scanning all active channels within the
bandwidth of 20 MHz. If it cannot find a suitable BSU, it will switch to a 10 MHz bandwidth and start scanning all
active channels within that bandwidth, in this case channel 100 first since it is configured as high priority and
channel 104 next. No channels will be scanned on the 5 MHz bandwidth since all those channels are configured
as inactive.