Operator's Manual

OM-E 2072-09689-00
A-3
A-4. LQA MEMORY
The ALE builds a database of connectivity information based on calls and the ALE sounding
messages transmitted by other stations in the network. This information is stored in a special LQA
memory and is used to determine the link quality of all channels in the networks. The data in the LQA
memory is time-weighted, that is, recent information is given more value than old, thus compensating
for changing propagation conditions.
A-5. BIDIRECTIONAL HANDSHAKE
The bidirectional handshake is an operator-initiated procedure used to exchange LQA scores with
other stations without establishing a link.
NOTE
The Micom-Z can also be programmed to automatically initiate the call
to the station after finishing the bidirectional handshake (using the
BDLK parameter reached under the ALE programming options).
This procedure is useful in the following cases:
• The radio has only recently been switched on and the automatic sounding cycle has not yet been
completed.
• The operator wishes to update the LQA scores before initiating a call to another station, for
example, for example, because of abrupt atmospheric charges, or other propagation changes.
• A new or passive station has joined the system.
A bidirectional handshake can be carried out with a single station or with all stations in the net. It can
be carried out either on a single channel, or on all the net channels. When required, a message can also
be added to the procedure.
After a bidirectional handshake with a single station, the LQA matrices of both radios are updated.
The operator can then initiate a call to that station and obtain the best channel automatically.
When the bidirectional handshake procedure is performed with a net, all the stations in the net update
their LQA tables.