Cerio OW-200N2, User Manual

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User’s Manual
500mW eXtreme Power 11Na Outdoor Bridge
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When you enable Short Slot and set Extra Slot time to “10”, the actual Slot Time=9+10 us.
When you disable Short Slot and set Extra Slot time to “10”, the actual Slot Time=20+10 us.
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ACK Timeout : ACK timeout is in the range of 1~255 and set in unit of microsecond . The default value is 32
microsecond.
All data transmission in 802.11b/g request an “Acknowledgement” (ACK) send by receiving radio. The transmitter
will resend the original packet if correspondent ACK failed to arrive within specific time interval, also refer to as
“ACK Timeout”.
ACK Timeout is adjustable due to the fact that distance between two radio links may vary in different deployment.
ACK Timeout makes significant influence in performance of long distance radio link. If ACK Timeout is set too
short, transmitter will start to “Resend” packet before ACK is received, and throughputs become low due to
excessively high re-transmission.
ACK Timeout is best determined by distance between the radios, data rate of average environment. The Timeout
value is calculated based on round-trip time of packet with a little tolerance, So, if experiencing re-transmissions
or poor performance the ACK Timeout could be made longer to accommodate.
Slot Time and ACK Timeout settings are for long distance links. It is important to tweak settings to achieve the
optimal result based on requirement.
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Beacon Interval : Beacon Interval is in the range of 20 ~ 1024 and set in unit of millisecond . The default value is
100 msec.
Access Point (AP) in IEEE 802.11 will send out a special approximated 50-byte frame, called “Beacon”. Beacon
is broadcast to all the stations, provides the basic information of AP such as SSID, channel, encryption keys,
signal strength, time stamp, support data rate.
All the radio stations received beacon recognizes the existence of such AP, and may proceed next actions if the
information from AP matches the requirement. Beacon is sent on a periodic basis, the time interval can be
adjusted.