Reference Manual

Table Of Contents
The Control List
210 2110 SSB Transceiver Reference Manual
With ALE calling, the transceiver may cycle through several channels before a link is
established. If you select Leading, the AMD data is always positioned in the leading part
of the call. The data will be transmitted prior to any response from the receiving station.
If the transceiver abandons this channel and moves to the next best channel, it will send
the AMD data again prior to any response being received. The leading position is
required for interoperability with older Codan transceivers (firmware earlier than V4.00)
and may be required for interoperability with transceivers from other vendors. If you
select Auto, the transceiver will determine the best position for the AMD data in the call.
It may move the AMD data from the leading part of the call, sending it after a response
has been received from the other station. Auto is the recommended setting.
ALE BER
ALE control information is sent and received in blocks of data called ALE words. Each
word is sent three times to reduce the effects of fading, interference and noise. When the
words are decoded the transceiver records the number of errors that occurred in the
transmission.
The number of errors indicates the quality of the channel used. A bit error rate of 0
indicates perfect reception. A bit error rate of 48 indicates that all bits of the ALE word
were bad.
The ALE BER entry enables you to specify the number of errors you will tolerate in this
test, which indicates the quality of the channels on which you are prepared to accept
calls. Also see page 211, ALE Golay.
ALE Call Threshold
When the quality of a channel is tested it is given an LQA score. This score is based on
the results of local and remote measurements for BER and SINAD and on the call
weighting value set in the ALE Call Weighting entry.
Generally, a score of 25% indicates the minimum acceptable standard for voice
communication. A score of 50% or higher indicates a good channel. The ALE Call
Threshold entry enables you to set:
the minimum score a channel must achieve for it to be tried in ALE calls
the minimum acceptable standard for the channel at the time when a link is being
established
NOTE
The ALE AMD Position entry is only effective in Auto when the
networks used to make the call have their Privacy Mode set to Plain.
CAUTION It is recommended that this entry is not altered from the factory setting.
NOTE
If the ALE LQA Exchange entry is set to Off, remote measurements are
not used.
NOTE
The transceiver will attempt to make calls on channels for which there is
no score, but only after channels with a score above the threshold have
been tried.