User Guide

NETNode Operations Guide
Commercial in
Confidence
IP Mesh Systems
000-130
R1.8 2015-07-24
Commercial in
Confidence
Page 2-48
Round Robin Mode 2.18.1
Round Robin mode simply looks for 10s at each active zone at a time and if a signal is found
joins that Network. If no signal is found or the current signal is lost then Round Robin moves
onto the next zone. Obviously with large numbers of zones this becomes very slow. The
other disadvantage with this mode of operation is that the NETNode will not leave the
network until the signal is lost even when alternate Networks may be available at higher
signal strengths. But it is simpler to configure than GPS location mode.
GPS Location Mode 2.18.2
For GPS Roaming, each zone contains a list of primary antenna (fixed) sites. For each site
the GPS location, height, and the antenna parameters are entered into the antenna base
sites panel.
For this mode to operate a GPS receiver must be connected to the roaming NETNode. Please
see section 2.4 on how to perform this task. The presence of a working GPS is indicated by
the 3D fix in the GPS Fix status box.
For each zone a path loss is calculated between the Roaming NETNode and each of the
individual sites. A number of path loss models are supported – the urban mode increases the
path loss at a quicker rate than the free space model and takes into amount antenna heights
(Egli’s model). The semi-urban model is a halfway house between the urban and free space
models. The loss also includes an over the horizon model (the aircraft applications). The
lowest loss from all sites and zones is calculated and then compared with the lowest loss of
all sites on the current zone. The NETNode will switch to the new zone if difference exceeds
a small threshold to allow for some hysteresis.
Up to five sites are supported per zone. For more than five fixed sites it is suggested
entering the principle sites around the periphery of the area. Latitude and Longitude data
can be readily acquired from the WEB using tools such as Google maps. The beam width box
allows for sector antennas to be specified. Setting the beam width to 360 assures an Omni
antenna. Setting the beam width to zero indicates that site is not in use.
GPS location may not work well in cluttered environments where the path loss and actual
signal strength do not correlate well. It is very suited to airborne applications.
Note: The GPS panel and data rate must be set correctly for all configurations which
roaming is used. If this is not done then the GPS will become disabled when the unit
changes configuration.
Downloading and Uploading Zone Data 2.18.3
Zone data may be downloaded and uploaded in to different units. To download the zone
data, on the browser manually type in the URL: http://ip_address_of_unit/roaming.json. The
resulting file can be saved to disk. This file is in JSON, or JavaScript Object Notation
format and can be easily edited in a text editor if required. The file can be uploaded back
into any unit by clicking the Roaming Upload Button, and entering the file name in the dialog
box.