Psion Inc 7505BTMW 用户手册

The Global settings tab allows you to define radio and security settings that apply to all pro-
files, along with settings that apply specifically to the SCU. The Global settings in the table 
below can be edited in SCU:

Table C.2  Global Tab

Global Setting

Description

Value

Default

Roam Trigger

If RSSI from AP is less than roam 
trigger value, radio performs roam scan 
or probes for an AP with stronger 
signal.

dBm: -50, -55, -60, -65, 
-70, -75, Custom

-75

Roam Delta

Amount by which second AP’s RSSI 
must exceed the moving average RSSI 
for the current AP before the radio will 
attempt to roam to a second AP.

dBm: 5, 10, 15, 20, 25, 
30, 35, Custom

10

Roam Period

Following an association or roam scan 
(with no roam), the number of seconds 
the radio collects RSSI scan data before 
considering roaming.

Seconds: 5, 10, 15, 20, 
25, 30, 35, 40, 45, 50, 
55, 60, Custom

10

BG Channel Set

Defines the 2.4 GHz channels to be 
scanned when the radio is set to roam 
and needs to determine what APs are 
available.

Full (all channels)
1, 6, 11
1, 7, 13
Custom

Full

DFS Channels

Reserved

Off, On

Off

Aggressive Scan

When this setting is On and the current 
connection to an AP becomes unrelia-
ble, the radio scans for available APs 
more aggressively. Aggressive scan-
ning complements and works in con-
junction with the standard scanning 
that is configured through the Roam 
Trigger, Roam Delta, and Roam Period 
settings. It is recommended that 
Aggressive Scan is left On unless there 
is significant co-channel interference 
because of overlapping coverage from 
APs on the same channel.

Off, On

On