User's Manual

ORiNOCO Wireless Client User Guide
Chapter 5 Troubleshooting 54
5-5 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 802.11 standards and the 2X Turbo mode specification support multiple data rates that
correspond to different transmission techniques. For wireless devices, there is a trade-off
between range and data rate. Transmission techniques that provide high data rates operate over
short distances; techniques that provide slower data rates operate over greater distances. By
default, the ORiNOCO Wireless Client automatically switches between these data rates to
maintain a usable radio connection and achieve the best data rate based on the card’s distance
from the Access Point. Therefore, a client that is close to an Access Point will operate at a higher
data rate than a client that is farther away from the Access Point.
The ORiNOCO Wireless Client includes two integral omnidirectional antennas. Note that the
coverage footprint of the card’s antennas will vary depending on the laptop’s design and the
location of the CardBus slot in the computer. Two antennas are provided to support antenna
diversity, a technique 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.
Proper antenna placement can help improve range. Here are some guidelines:
• Try to keep the card’s antennas free of obstructions (particularly metal objects) and do not
place a sheet of metal (like a filing cabinet) between the antennas of two 802.11 devices.
• Use the Proxim Client Utility to evaluate the signal strength and link quality between
802.11 devices.
• Refer to the documentation that came with your Access Points for suggestions on how to
locate the AP and its antennas to maximize range and performance.