Using Automatic Link Establishment (ALE)
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the addresses of the desired subset of receiving stations (that is, it replaces the ? with an alphanumeric
– see more details in Table 1). If even narrower acceptance and response criteria are required,
double selective AnyCall may be used: this is identical to selective AnyCall, except that its special
address (@AB) specifies the last two characters that the desired subset of receiving stations.
The operator can always initiate an outgoing (transmit) AnyCall, but the MICOM-3 can be
programmed to accept or ignore incoming (receive) AnyCalls.
Any station accepting an AnyCall stops scanning, and then initiates a response in a randomly selected
timeslot.
Self Addresses
Stations can also use their own self addresses when making calls. This may be useful for self-test and
maintenance purposes, etc.
The self address may be used only in specifically-addressed calls including a group call, but not in an
AllCall or AnyCall.
Null Address
The null address is a special type of address that is not directed to, accepted by, or responded to by
any station.
This address is intended for test and maintenance purposes, and to provide buffer time: for example,
if a null address appears in a group call, no station will respond in the associated timeslot.
Inlink Address
The inlink address, ?@?, is used to instruct all the stations participating in an already established link
to accept and act upon the information sent with the inlink address. For example, any station can use
the inlink address to send an AMD message that all the linked stations would present to their user.
The inlink address is recognized only after a link is established between two or more stations.
Using the MultiNet Feature
Normally, a radio operating in the ALE mode receives and transmits only in its currently selected net.
However, there are operational scenarios in which it is beneficial to enable radios to use the ALE
functions while still being aware of what is going on in additional nets (for example, firefighters and
paramedics must often respond to the same emergency), and be able of answering a call in another
net. For this purpose, MICOM-3 radios offer the MultiNet feature.
When the MultiNet feature is enabled, a MICOM-3 radio can operate on multiple nets (up to 20).
The operating characteristics then change as follows:
• Channels: each net has a group of assigned (receiving and associated transmitting) frequencies.
The radio scans the channels in one net after the other, until all the nets have been scanned.
• Station addresses (the self-address and the net address used when responding to calls): the radio
responds according to the self-address assigned to the station in its currently selected net (for a
total of up to 20 self-addresses).
• Sounding: each radio sends soundings only within the currently selected net. Each radio scans all
the channels in the currently selected net, one by one. Sounding is started 10 minutes after the
unit is switched on. The sounding group interval is determined according to the programmed
Sounding Auto Time.
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