HP ProCurve 420 Management And Configuration Manual page 113

Beacon Interval: The rate at which beacon frames are transmitted from
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the access point. The beacon frames allow wireless clients to maintain
contact with the access point. They may also carry power-management
information.
■ Data Beacon Rate: The rate at which stations in sleep mode must wake
up to receive broadcast/multicast transmissions.
Known also as the Delivery Traffic Indication Map (DTIM) interval, it
indicates how often the MAC layer forwards broadcast/multicast traffic,
which is necessary to wake up stations that are using Power Save mode.
The default value of 2 indicates that the access point will save all broad-
cast/multicast frames for the Basic Service Set (BSS) and forward them
after every second beacon. Using smaller DTIM intervals delivers broad-
cast/multicast frames in a more timely manner, causing stations in Power
Save mode to wake up more often and drain power faster. Using higher
DTIM values reduces the power used by stations in Power Save mode, but
delays the transmission of broadcast/multicast frames.
RTS Threshold: Sets the packet size threshold at which a Request to Send
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(RTS) signal must be sent to a receiving station prior to the sending station
starting communications. The access point sends RTS frames to a
receiving station to negotiate the sending of a data frame. After receiving
an RTS frame, the station sends a CTS (clear to send) frame to notify the
sending station that it can start sending data.
If the RTS threshold is set to 0, the access point never sends RTS signals.
If set to 2347, the access point always sends RTS signals. If set to any other
value, and the packet size equals or exceeds the RTS threshold, the RTS/
CTS (Request to Send / Clear to Send) mechanism will be enabled.
Slot Time: Sets the basic unit of time the access point uses for calculating
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waiting times before data is transmitted.
• Short: Sets the slot time to short (9 microseconds). A short slot time
can increase data throughput on the access point, but requires that
all clients can support a short slot time (that is, 802.11g-compliant
clients must support a short slot time).
• Long: Sets the slot time to long (20 microseconds). A long slot time
is required if the access point has to support 802.11b clients.
• Auto: Sets the slot time according to the capability of clients that are
currently asscociated. When the Working Mode is set to g only mode
or b & g mixed mode the access point initially uses a short slot time,
but if an 802.11b client attempts association, it automatically changes
to using a long slot time. When the Working Mode is set to b only mode,
the access point always uses a long slot time.
Access Point Configuration
Modifying Radio Settings
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