LevelOne WHG-1000 - Manual (Page 37)

WHG-1000 300Mbps Wireless PoE Hotspot Gateway
User's Manual
37
4.2.2 Configure Wireless Advanced Setup
The administrator can change the Slot Time, ACK Timeout, RTS threshold and fragmentation threshold settings for
the system. Please click on Wireless
→ Advanced Setup and follow the below setting.
 Slot Time : Slot time is in the range of 9~1489 and set in unit of microsecond. The default value is 9
microsecond.
Slot time is the amount of time a device waits after a collision before retransmitting a packet. Reducing the slot
time decreases the overall back-off, which increases throughput. Back-off, which is a multiple of the slot time, is
the random length of time a station waits before sending a packet on the LAN. For a sender and receiver own
right of the channel the shorter slot time help manage shorter wait time to re-transmit from collision because of
hidden wireless clients or other causes. When collision sources can be removed sooner and other senders
attempting to send are listening the channel(CSMA/CA) the owner of the channel should continue ownership
and finish their transmission and release the channel. Then, following ownership of the channel will be sooner
for the new pair due to shorter slot time. However, when long duration of existing collision sources and shorter
slot time exist the owners might experience subsequent collisions. When adjustment to longer slot time can’t
improve performance then RTS/CTS could supplement and help improve performance.
 ACK Timeout : ACK timeout is in the range of 1~372 and set in unit of microsecond. The default value is 64
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”.