User's Manual

Troubleshooting 42
Range
Every environment is unique with different obstacles, barriers, materials, etc., and,
therefore, it is difficult to determine the exact range that will be achieved without
testing. Radio signals may reflect off of some obstacles or be absorbed by others
depending on their construction.
The IEEE 802.11a specification supports eight data rates: 54 Mbps, 48 Mbps,
36 Mbps, 24 Mbps, 18 Mbps, 12 Mbps, 9 Mbps, and 6 Mbps. Harmony’s 2X mode
supports eight data rates: 108 Mbps, 96 Mbps, 72 Mbps, 48 Mbps, 36 Mbps, 24
Mbps, 18 Mbps, and 12 Mbps. Operation at 6 Mbps or 12 Mbps provides greater range
than operation at 54 Mbps or 108 Mbps.
By default, the Harmony 802.11a PCI Card will automatically adjust the data rate to
maintain a usable radio connection. Therefore, a client that is close to an Access
Point may operate at 54 Mbps while a client that is on the fringe of coverage may
operate at 6 Mbps.
Proper antenna placement can help improve range. Try to keep the PCI Card’s integral
antennas free of obstructions (particularly metal objects) and do not place a sheet of
metal (like a filing cabinet) between 802.11a devices. Also, Proxim recommends that
you use the Harmony Utility to evaluate the signal strength and link quality between
802.11a devices.