RLX2-IHx Series ♦ 802.11a, b, g, n
Configuring a Radio - Detailed Configuration
Industrial Hotspots
User Manual
ProSoft Technology, Inc.
Page 97 of 248
Scan Dwell
This parameter determines the amount of time in milliseconds that the
RLX2-IHx will wait on a channel to hear Beacons or responses to its
Probe Request. The value must be a multiple of 10.
The Radio buttons to the left of the Scan Dwell edit box configure
whether the Background Scan will be Passive or Active.
In a passive scan the unit does not transmit a Probe Request but waits
on the channel for the Dwell interval and processes any received
Beacon. For this reason a larger value for Scan Dwell should be
configured when Passive is enabled, if possible, to increase chances
of detecting a Beacon which are transmitted by APs typically every
100 msec.
Passive Background Scans would be preferred when operating in a
network where there are a very large number (>50) of RLX2-IHx
Client/Repeaters within range of each other on the same channel.
Active Scanning under these conditions would use up a significant
amount of a channel’s bandwidth with Probe Requests and Probe
Responses.
In an active scan a Probe Request is sent to the channel to elicit a
Probe Response from a potential parent candidate. The Probe
Request contains the desired SSID, therefore only APs that are
configured with that SSID will respond.
Note:
Given that Probe Requests are broadcast and may not be heard
due to collisions with other traffic on the air, it may take multiple scans
of a channel before a response is heard.
The default value of 30 msec should be sufficient to receive any Probe
Responses from a typical AP.
Scan Interval
The RLX2-IHx will initiate background scans at every
Scan Interval
as
long as the current Parent’s RSSI is less than the value of the
Scan
Threshold
parameter.
Smaller values imply that background scans will occur more frequently
whereas a larger value (up to 5 sec) imply it may take longer to find a
Parent candidate on another channel. The value is in units of
milliseconds and must be a multiple of 10.
Channels/Scan
This parameter determines the number of channels from the channel
scan list that are scanned at each background scan interval.
Each background scan starts from the channel after the last channel
scanned on the last interval.
Note:
Normal data traffic is paused during a background scan,
therefore the higher this number the longer the pause in data traffic
flow.