Operating Manual 6175.4760.02 – 01 4.81
M3SR Series 4100 Selecting the Call Channel Type
4.4.4.4 Selecting the Call Channel Type
Softkey Type Description
Listbox 1. Press 'CCT' softkey.
2. Select desired call channel type from list-
box.
3. Press 'ENT' to confirm.
The new call channel type is now selected.
Possible values:
• next channel
• best channel
• fixed channel
Next Channel:
The next link will be set up on the next possible 
channel in the scanning cycle. If a link setup 
fails, the radio uses a backoff strategy to select 
the channel for the next link setup attempt.
With this selection, the link setup is very fast, 
but the choice depends on the starting time of 
the call, not on the channel quality. Useful 
only, if the conditions are very good on all 
channels.
Best Channel:
It is recommended to use this call channel type 
as often as possible  to let the ALE search for 
the best available channel.
The next link will be set up on the channel with 
the best signal-to-noise ratio (S/N). For this the 
radio consults its link quality table.
If a link setup fails, the radio uses a backoff 
strategy to select the channel for the next link 
setup attempt.
Fixed Channel:
The ALE call will be initiated on an operator-
chosen channel. If a link setup fails, the radio 
waits a random time until the fixed channel is 
met again. Useful for experienced operators 
and known channel conditions.