ARA-1 Operations Manual
1-2
INTEROPERABILITY NOW
Alternatively, the ARA-1 can assign an IP address to its associated radio for communications
over any IP-based network or the Internet with another SIP-enabled device (such as a SIP Phone,
a softphone, or another radio/ARA-1 pair). The radio side of the interface makes full use of the
extensive suite of digital signal processor algorithms, hundreds of interface cables, and numerous
problem-solving techniques that JPS has evolved during more than a decade as the market leader
in radio interoperability.
Figure 1-1
ARA-1 Basic Block Diagram
1.2.3
Why SIP?
The main goals of modern communications system design include: convergence of voice, data,
and video; standards-based, open protocols; and individual IP addresses for all end devices.
Session Initiation Protocol, SIP, is widely seen as the preferred pathway to achieving these goals.
SIP is a signaling protocol used to create, manage, and terminate sessions in an IP-based network.
A session could be a simple two-party call or a multimedia conference session. SIP focuses on
the setup, modification, and termination of sessions allowing versatility of the format and content
of the data being shared. Since SIP is a standards-based, open protocol, SIP system operators can
pick and choose among third-party vendors when selecting existing or future applications to add
to their systems. This avoids the single-vendor “lock-in” that can occur with closed proprietary
protocols. JPS also sells a similar device, the NXU-2A, which uses a proprietary protocol that
JPS created for best operation with radio networks.
1.3
Network Details
The ARA-1 is a 10/100BASE-T Ethernet device, and each unit has a unique Ethernet address
and an RJ-45 physical interface jack. A 10/100BASE-T device operates at either 10 or 100 Mbps
and interconnects to an Ethernet hub or switch using standard CAT 5 twisted pair cable. The
maximum cable length between an ARA-1 and its hub port is 100 meters. With the right
connective equipment (recommended or supplied by JPS), the ARA-1’s Ethernet port can be
linked with virtually any LAN, WAN, or the Internet, no matter which topology or cabling system
is in use.