Motorola WiNG 4.4 Reference Manual page 202

4 - 98 WiNG 4.4 Switch System Reference Guide
17.To configure optional rate settings, click the
information. Instructions on configuring rate settings is described in
18.In most cases, the default settings for the
Properties can be modified for the following:
Antenna Diversity
Maximum MUs
Adoption
Preference ID
Short Preambles
only
RTS Threshold
Rate Settings
Advanced Properties
Use the drop-down menu to configure the Antenna Diversity settings for Access Ports using
external antennas. Options include:
• Full Diversity - Utilizes both antennas to provide antenna diversity.
• Primary Only - Enables only the primary antenna.
• Secondary Only - Enables only the secondary antenna.
• MIMO: Multiple-Input and Multiple-Output. This field is only available with type 'n' radios.
Antenna Diversity should only be enabled if the Access Port has two matching external
antennas. Default value is Full
Sets the maximum number of MUs that can associate to a radio. The maximum number of
MUs that can associate to a radio is 64.
Displays the preference ID of the switch.The value can be set between 1 and 65535. To define the radios
as preferred, the Access Port preference ID should be the same as adoption preference ID.
The adoption preference ID is used for AP load-balancing. A switch will preferentially adopt
APs, which have the same adoption-preference-ID as the switch itself.
If using an 802.11bg radio, select this checkbox for the radio to transmit using a short
preamble. Short preambles improve throughput. However, some devices (SpectraLink
phones) require long preambles. This checkbox does not display if using an 802.11a radio.
Specify a Request To Send (RTS) threshold (in bytes) for use by the WLAN's adopted Access Ports.
RTS is a transmitting station's signal that requests a Clear To Send (CTS) response from a receiving
station. This RTS/CTS procedure clears the air where many MUs are contending for transmission time.
Benefits include fewer data collisions and better communication with nodes that are hard to find (or
hidden) because of other active nodes in the transmission path.
Control RTS/CTS by setting an RTS threshold. This setting initiates an RTS/CTS exchange for data
frames larger than the threshold, and sends (without RTS/CTS) any data frames smaller than the
threshold.
Consider the trade-offs when setting an appropriate RTS threshold for the WLAN's Access Ports. A
lower RTS threshold causes more frequent RTS/CTS exchanges. This consumes more bandwidth
because of additional latency (RTS/CTS exchanges) before transmissions can commence. A
disadvantage is the reduction in data-frame throughput. An advantage is quicker system recovery from
electromagnetic interference and data collisions. Environments with more wireless traffic and
contention for transmission make the best use of a lower RTS threshold.
A higher RTS threshold minimizes RTS/CTS exchanges, consuming less bandwidth for data
transmissions. A disadvantage is less help to nodes that encounter interference and collisions.
An advantage is faster data-frame throughput. Environments with less wireless traffic and
contention for transmission make the best use of a higher RTS threshold. Default is 2346.
In 802.11b/g mixed RTS/CTS happens automatically. There is no way to disable RTS/CTS
unless the network and all the devices used are 802.11g or 802.11a only. The proper co-
existence of 802.11b and 802.11g is ensured through RTS/CTS mechanism. On 802.11g radios,
CTS-to-self is enabled irrespective of whether or not 11b rates are enabled or disabled.
When ERP Protection is ON, the 11bg radio will perform a CTS-to-self before it transmits the
frame.
button to display a new dialogue containing rate setting
Configuring Rate Settings on page
are sufficient. If needed, additional Advanced
Diversity.
4-100.