Fortress Technologies BreadCrumb Wireless Network - Manual (Page 23)

Chapter 4. Deployment Considerations
In some cases, however, it is necessary to manually set the radios to specific channels as described below.
Channel Assignment for Single-Radio BreadCrumb Devices (ME
and WE)
Single-radio BreadCrumb devices (models ME and WE) present a challenge for deployments in which
those BreadCrumb devices are needed to provide critical links within a mesh. For these deployments, it
is imperative that any BreadCrumb devices with which the ME or WE is to mesh have a channel in
common with the ME or WE.
The upshot of this is that the ME/WE and its intended peers should have their radio channels set
manually in order to ensure common channels.
Channel Assignment for Long-Range BreadCrumb Devices (XL,
XLV, XLE)
Long-range BreadCrumb devices include additional circuitry that is permanently tuned to 802.11b
channels 1 and 11. For these BreadCrumb devices, radio 1 must always be set to channel 1 and radio 2
must always be set to channel 11.
Physical Placement and Other Considerations
Commonly occurring environmental factors have a significant impact on performance and behavior of
the BreadCrumb Wireless Network. LOS (Line of Sight) obstructions, distance, weather, and device
placement should all be considered when deploying a wireless network.
802.11b wireless operation degrades gracefully as distance increases between nodes or as interference
becomes prominent. This manifests as a data rate reduction between nodes.
The goal in planning and deploying a BreadCrumb Wireless Network is to maximize both coverage and
the data transfer rate between devices. These can be maximized by taking into consideration all of the
contributing factors described in this section.
Line Of Sight
Unobstructed LOS is critical for optimal performance of the BCWN. Partial LOS obstructions results in
noticeable network performance degradation. Total LOS obstruction can result in complete loss of
network connectivity.
Elevating the device and external antenna will assist in providing better LOS. This can allow the radio
waves to travel over possible obstructions. In an open area, at least two meters (six feet) of antenna
elevation are recommended.
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