ARA-1 Operations Manual
INTEROPERABILITY NOW
1-5
The second setup in Figure 1-3 shows a pair of radio systems connected via the ARA-1
technology and the network. These radio systems may be on opposite sides of the country, or
they may be collocated, but on different frequencies or bands.
The third setup shows a connection between a softphone and a radio through the ARA-1. This
operation is identical to the SIP Phone application.
1.4.3
Use of the ARA-1 with a Repeater System
It is important to note that the ARA-1 makes a connection not to a single radio or single radio
user, but to an entire
radio system
. All signals picked up by the radio are relayed through the
ARA-1, and more importantly, transmissions through the ARA-1 are sent to all radios that can
pick up this transmission.
In many cases, the ARA-1 and radio will be used within a repeater system. The radio associated
with the ARA-1 will create an RF link to a repeater system as illustrated in Figure 1-4.
Figure 1-4
ARA-1 with a Repeater System
Whenever the SIP Phone user connected to the radio/ARA-1 pair speaks, the radio transmits.
This transmission is picked up by the repeater system, which retransmits it to all the mobile and
handheld radio users in the system. Similarly, all of their transmissions are retransmitted by the
repeater system to be received by all system users, including the radio associated with the ARA,
so all of this traffic can be heard by the SIP Phone user.