HP ProCurve 520wl Wireless Access Point - Manual (Page 53)

Advanced Configuration
• Distance Between APs: Set to Large, Medium, Small, Microcell, or Minicell depending on the site survey for
your system. By default, this parameter is set to Large. The distance value is related to the Multicast Rate
(described next). In general, a larger distance between APs means that your clients operate a slower data rates
(on average). See
Distance Between APs for more information.
• Multicast Rate: Sets the rate at which Multicast messages are sent. This value is related to the Distance Between
APs parameter (described previously). The table below displays the possible Multicast Rates based on the
Distance between APs setting. By default, this parameter is set to 2 Mbits/sec. See
Multicast Rate for more
information.
Distance between APs Multicast Rate
Large
1 and 2 Mbits/sec
Medium 1, 2, and 5.5 Mbits/sec
Small 1, 2, 5.5 and 11 Mbits/sec
Minicell 1, 2, 5.5 and 11 Mbits/sec
Microcell 1, 2, 5.5 and 11 Mbits/sec
• DTIM Period: The Deferred Traffic Indicator Map (DTIM) is used with clients that have power management
enabled. DTIM should be left at 1, the default value, if any clients have power management enabled. This
parameter supports a range between 1 and 255.
• RTS/CTS Medium Reservation: This parameter affects message flow control and should not be changed under
normal circumstances. Range is 0 to 2347. When set to a value between 0 and 2347, the Access Point uses the
RTS/CTS mechanism for packets that are the specified size or greater. When set to 2347 (the default setting),
RTS/CTS is disabled. See
RTS/CTS Medium Reservation for more information.
• Interference Robustness: Enable this option if other electrical devices in the 2.4 GHz frequency band (such as a
microwave oven or a cordless phone) may be interfering with the wireless signal. The AP will automatically
fragment large packets into multiple smaller packets when interference is detected to increase the likelihood that
the messages will be received in the presence of interference. The receiving radio reassembles the original packet
once all fragments have been received. This option is disabled by default.
• Closed System: Check this box to allow only clients configured with the Access Point’s specific Network Name to
associate with the Access Point. When enabled, a client configured with the Network Name “ANY” cannot connect
to the AP. This option is disabled by default.
• Load Balancing: Enable this option so clients can evaluate which Access Point to associate with, based on
current AP loads. This feature is enabled by default; it helps distribute the wireless load between APs. This feature
is only available when using an HP ProCurve Wireless 802.11b AP Card 150wl. In addition, this feature will only
give information for ORiNOCO/Agere/Lucent based clients.
• Medium Density Distribution: When enabled, the Access Point automatically notifies wireless clients of its
Distance Between APs, Interference Robustness, and RTS/CTS Medium Reservation settings. This feature is
enabled by default and allows clients to automatically adopt the values used by its current Access Point (even if
these values differ from the client’s default values or from the values supported by other Access Points). This
feature is only available when using an HP ProCurve Wireless 802.11b AP Card 150wl. In addition, this feature will
only give information for ORiNOCO/Agere/Lucent based clients.
Distance Between APs
Distance Between APs defines how far apart (physically) your AP devices are located, which in turn determines the
size of your cell. Cells of different sizes have different capacities and, therefore, suit different applications. For
instance, a typical office has many stations that require high bandwidth for complex, high-speed data processing. In
contrast, a typical warehouse has a few forklifts requiring low bandwidth for simple transactions. This feature is only
available when using an HP ProCurve Wireless 802.11b AP Card 150wl.
Cell capacities are compared in the following table, which shows that small cells suit most offices and large cells suit
most warehouses:
Small Cell Large Cell
Physically accommodates few stations Physically accommodates many stations
High cell bandwidth per station Lower cell bandwidth per station
High transmit rate Lower transmit rate
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