Ubee Interactive
Deploying and Troubleshooting the Wireless Network
Ubee DDW365 Wireless Cable Modem Subscriber User Guide • October 2013
78
5. Use the attenuation value from the materials table above in the following formula:
Formula:
(Transmit Power,
use -30dBm
)
–
(Receiver Sensitivity,
use RSSI value
)
=
Allowable Free Space Loss
Allowable Free Space Loss
÷
Materials Attenuation Value
=
Optimal Distance in Feet Between the Cable Modem and a Wireless Client
Example:
(-30dBm)
-
(-67dBm)
=
37dBm (allowable free space loss for a 54Mbps
connection)
37dBm
÷
.24db/foot (for open space)
=
154.16 feet
6. Once you know the optimal feet distance between individual wireless clients and the
wireless cable modem, you may resolve and prevent some performance issues.
7. To check the wireless signal strength and speed, use the following steps for a
Windows computer connected wirelessly to the wireless cable modem. If the wireless
computer is not connected, refer to
Connecting a Wireless Device on page 11
.
a. Click the Wireless networking icon in the system tray to display a list of available
wireless networks.
b. Click the Wireless networking icon, click “Open Network and Sharing Center,” then
click “Wireless Network Connection.”
c. Review the speed and signal strength in the Status window.
Human Body
3dB
Trees (Note 2)
0.15dB / foot
Note 1
: Different types of concrete materials are
used in different parts of the world and the thickness
and coating differ depending on whether it is used in
floors, interior walls, or exterior walls.
Note 2
: The attenuation caused by trees
varies significantly depending upon the shape
and thickness of the foliage.
Attenuation Considerations at 2.4GHz
Material
Attenuation
