Omega Vehicle Security Wireless Sensor System zSeries - Manual (Page 65)

5.1 General Deployment Guidelines (continued)
7. Where possible, try to ensure an uninterrupted line-of-sight between nodes.
Avoid obscuring objects (e.g. metal pillars, posts, sign) near the antenna. A close
object obscures a wider range of solid angle.
8. It is important to understand that the environment may change over time due to
new equipment or machinery being installed, building construction, etc. If new
obstacles exist between your End Device and Coordinator, antenna angle may
need to be re-adjusted and/or the unit has to be relocated.
9. An IEEE 802.15.4 wireless network will not work under water. Wet condition (e.g.
in heavy rainfall) may exhibit some degradation. In most cases, water droplets on
or close to the antenna are more serious than the rain itself. Humidity can affect
radio performance as well.
10. Reduced performance scenario:
a. A large building may have few obstructions between nodes but large amount
of metallic paneling that cause reflections.
b. A small domestic installation may have numerous brick walls between nodes
in individual rooms.
c. An office building may have metalized dry-wall partitions together with
mezzanine ceilings.
Figure 5.1 Operation in Buildings
Data is sent through radio signal at 2.4 GHz. Radio signals are electromagnetic
waves, hence the signal becomes weaker the further it travels.
While radio waves can penetrate some solid materials like a wall, they can
diminish more than when a direct line-of-sight between the transmitting and
receiving antenna exist.
Therefore, it is generally a good idea to place Coordinator at the center while
End Devices are located about the same distance away from it. If possible,
keeping clearance around the line of site will improve performance as well.
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