User's Manual

Parameter Description
Maximum number of spatial
streams usable for STBC
transmission.
Controls the maximum number of spatial streams usable for STBC
transmission. 0 disables STBC transmission, 1 uses STBC for MCS 0-7.
Higher MCS values are not supported. (Supported on W-AP90 series, W-
AP175, W-AP130 Seriesand W-AP105 only. The configured value will be
adjusted based on AP capabilities.)
MPDU Aggregation Enable or disable MAC protocol data unit (MPDU) aggregation.
High-throughput APs are able to send aggregated MAC protocol data units
(MDPUs), which allow an AP to receive a single block acknowledgment
instead of multiple ACK signals. This option, which is enabled by default,
reduces network traffic overhead by effectively eliminating the need to
initiate a new transfer for every MPDU.
Max received A-MPDU size Maximum size of a received aggregate MPDU, in bytes. Allowed values:
8191, 16383, 32767, 65535.
Max transmitted A-MPDU size Maximum size of a transmitted aggregate MPDU, in bytes.
Range: 1576–65535
Min MPDU start spacing Minimum time between the start of adjacent MPDUs within an aggregate
MPDU, in microseconds. Allowed values: 0 (No restriction on MDPU start
spacing), .25 µsec, .5 µsec, 1 µsec, 2 µsec, 4 µsec.
Short guard interval in 20 MHz
mode
Enable or disable use of short (400ns) guard interval in 20 MHz mode. This
parameter is enabled by default.
A guard interval is a period of time between transmissions that allows
reflections from the previous data transmission to settle before an AP
transmits data again. An AP identifies any signal content received inside
this interval as unwanted inter-symbol interference, and rejects that data.
The 802.11n standard specifies two guard intervals: 400ns (short) and
800ns (long). Enabling a short guard interval can decrease network
overhead by reducing unnecessary idle time on each AP. Some outdoor
deployments, may, however require a longer guard interval. If the short
guard interval does not allow enough time for reflections to settle in your
mesh deployment, inter-symbol interference values may increase and
degrade throughput.
Dell Networking W-Series ArubaOS 6.4.x | User Guide Virtual APs | 427