Troubleshooting
43
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.
Note:
APs sold in Europe, Japan, and Singapore do not support 2X mode.
By default, a Harmony 802.11a Access Point will automatically adjust the data rate to
maintain a usable radio connection with its clients. 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. Note that if you specify a single data rate for the Access Point,
you may reduce the effective range of the Harmony 802.11a products.
The Harmony 802.11a Access Point includes two integral antennas or two antenna
connectors to support antenna diversity, which can improve system reliability. Due to
the characteristics of radio waves, it is possible that one antenna may provide better
performance than a second antenna installed a short distance away. Only one
antenna is used at a time; they cannot be used simultaneously to increase the Access
Point’s coverage area.
Proper antenna placement can help improve range. Here are some guidelines:
•
Keep the antennas free of obstructions. Do not install an antenna next to a metal
object.
•
Do not place a sheet of metal (like a filing cabinet) between the antennas of two
802.11a products.
•
Place the Access Point as high as possible. In an office environment, try to place
it above cubicle walls.
•
To achieve the best range, Proxim recommends that you position both of the AP’s
antennas so they are perpendicular to the floor/ceiling.
•
If you experience coverage problems at short or medium range, you may be able
to improve performance by positioning the antenna closest to the AP’s Ethernet
port so that it is parallel to the floor/ceiling. The antenna closest to the AP’s
power connector should always be perpendicular to the floor/ceiling.
•
If you are mounting the Access Point on a wall and want to provide coverage
between floors, position the antenna closest to the Ethernet port so that it is par-
allel to the floor/ceiling. The antenna closest to the power connector should
always be perpendicular to the floor/ceiling.
