Model RF Obstacles 133
Model RF Obstacles When planning a 3Com network, you need to consider how the building
layout and physical objects affect signal loss. Walls, windows, and doors
absorb RF signals, and different building materials have different
attenuation factors.
You can model an RF obstacle on your floor plan and assign the obstacle
type and attenuation factor, or you can assign an obstacle type and
attenuation factor to objects in a DWG or DXF drawing. 3WXM uses
these values when calculating coverage for the network.
If you do not have an imported drawing, or if you are working with a GIF
or JPEG image, you must create RF obstacles manually. If you are using an
imported CAD drawing, you can convert many of the objects in the
drawing into RF obstacles. All objects similar in construction material
should be placed in one layer. For example, if the drawing file has walls
spread out in different layers, but after performing a site-survey, they
walls were found to be similar in material construction, it is better to put
them in one layer. In this way, the RF attenuation assignment can be
performed in one step.
This section show how to select and draw objects and convert them into
RF obstacles. 3WXM preserves the layers defined in a CAD drawing.
Table13 provides some common AutoCAD layer terminology.
To create RF obstacles for all objects in a layer
1Click Layers in the Organizer panel to bring up a list of the layers in the
drawing.
2Right-click one of the layers in the Organizer panel.
Table13 Common AutoCAD Layer Terminology
AutoCAD Layer Name Commonly Represents...
glaz windows
scol steel columns
p-fixt bathroom
p-part bathroom stall partitions
ext
int
exterior
interior