W900iTR User Guide
1-3
1.3 Operation
The W900iMTR Radio allows the user to create a long-range, wireless Ethernet network with up to 16
subscriber units per access point. The configuration may include any combination of AW900MTR,
AW900XTR and AW900XTP radios. (Please note that older AvaLAN 900 MHz radios can exist on the
same LAN but cannot be used to form wireless links with the AW900MTR/XTR/XTP units because link
encryption protocols have changed.)
Configuring a wireless link with the AW900MTR requires the establishment of six elements:
Each radio must know whether it is to be an access point (AP) or subscriber unit (SU).
Each radio must have an IP address that is unique among all others on the same network.
The AP must know how many SUs are expecting communication with it.
The AP and any given SU must agree on which radio frequency channel they are using. This can be
manually set or allowed to change automatically.
The SU must be assigned a unique subscriber ID to specify which time division slot it will use
when communicating with the AP.
The AP and any given SU must share a common 128-bit encryption key.
AW900MTR radios may be configured by two different methods. They may be connected to a computer
that will run a web browser, setting parameters via their built-in browser interfaces. They may also be
programmed via the older “easy key” method using the DIP switches and LEDs on the module.
If you wish to use the older method, go to the Old Method section and follow the procedures there.
The access point (AP) automatically scans for the best of the 12 available radio frequency channels,
encrypts Ethernet data received from the network, and transmits it wirelessly to the correct subscriber unit
(SU). The AP is constantly monitoring the radio link and can automatically change the channel if
performance is degraded due to interference. If two AP units are very close to one another, they may
interfere if operating on adjacent frequency channels. Place them at least 10 feet apart or manually select
non-adjacent channels for their operation. Also, the SU should be placed at least 10 feet from the AP to
avoid overloading the radio’s receiver.
The access point (AP) automatically scans for the best of the 12 available radio frequency channels,
encrypts Ethernet data received from the network, and transmits it wirelessly to the correct subscriber unit
(SU). The AP is constantly monitoring the radio link and can automatically change the channel if
performance is degraded due to interference. If two AP units are very close to one another, they may
interfere if operating on adjacent frequency channels. Place them at least 10 feet apart or manually select
non-adjacent channels for their operation. Also, the SU should be placed at least 10 feet from the AP to
avoid overloading the radio’s receiver.
Any 10/100 BaseT Ethernet client device (ECD) can be connected to an AW900MTR subscriber unit. Each
SU encrypts Ethernet traffic received from the attached ECD and transmits the data wirelessly to its AP.
Each SU can be plugged directly into an ECD without adding drivers or loading software. Essentially, once
the AP/SU pair is configured and running it behaves like a continuous Ethernet cable.
