NetComm NB9WMAXX User Manual page 39

Fragmentation Threshold
RTS Threshold
DTIM Interval
Beacon Interval
XpressTM Technology
54gTM Mode
54g Protection
Preamble Type
Transmit Power
About Xpress Technology
1. TM
Xpress Technology is a Broadcom innovation that dramatically improves wireless performance for suitably equipped client workstations while ensuring
TM
compatibility with 802.11b and 802.11g devices. Basically, Xpress
very fast data transfer rates with other Xpress
If you are communicating with Xpress
NB9WMAXX ADSL+ VoIP Router
YML89 Rev1
Enter a value between 256 (min) and 2346 (max).
A threshold, specified in bytes, that determines whether packets will be fragmented and
at what size. On an 802.11 WLAN, packets that exceed the fragmentation threshold are
fragmented, i.e., split into smaller units suitable for the circuit size. Packets smaller than the
specified fragmentation threshold value are not fragmented.
If you experience a high packet error rate, try to slightly increase your 'Fragmentation
Threshold'. The value should remain at its default setting of 2346 unless you are
troubleshooting wireless network issues. Setting the 'Fragmentation Threshold' too low may
result in poor performance.
Request To Send, set in bytes, specifies the packet size beyond which the WLAN Card
invokes its RTS/CTS (Clear To Send) mechanism. Packets that exceed the specified RTS
threshold trigger the RTS/CTS mechanism. The NIC (Network Interface Card) transmits
smaller packet without using RTS/CTS.
The default setting of 2347 (maximum length) disables RTS Threshold.
Delivery Traffic Indication Message (DTIM), also known as Beacon Rate. The entry range is
a value between 1 and 65535. A DTIM is a countdown informing clients of the next window
for listening to broadcast and multicast messages. When the NB9WMAXX has buffered
broadcast or multicast messages for associated clients, it sends the next DTIM with a
DTIM Interval value. AP Clients hear the beacons and awaken to receive the broadcast and
multicast messages. The default is 1.
The amount of time between beacon transmissions. Each beacon transmission identifies
the presence of an wireless client (or access point). By default, WLAN passively scan all RF
channels and listen for beacons coming from access points to find a suitable access point.
Before a station (wireless client) enters power save mode, the station needs the beacon
interval to know when to wake up to receive the beacon (and learn whether there are
buffered frames at the access point).
The entered value is represented in ms. Default is 100. Acceptable entry range is 1 to 0xffff
(65535).
Select 'enable' to activate in-built Xpress
Select the mode to '54g Auto' for the widest compatibility. Select the mode to '54g
Performance' for the fastest performance with 54g certified equipment. Set the mode to
'54g LRS' if you are experiencing difficulty communicating with legacy 802.11b equipment.
In 'Auto' mode the NB9WMAXX will use RTS/CTS to improve 802.11g performance in mixed
802.11g/802.11b networks. Turn protection 'Off' to maximize 802.11g throughput under
most conditions.
Short preamble is intended for application where maximum throughput is desired but it
doesn't cooperate with the legacy.
Long preamble interoperates with the current 1 and 2 Mbit/s DSSS specification as
described in IEEE Std 802.11-1999
The router will set different power output (by percentage) according to this selection.
TM will communicate at the maximum rate sustainable for each class of device, and also provide
TM -compatible network devices allowing a total theoretical bandwidth of 108Mbps.
-equipped wireless network client machines, enable Xpress
TM
Technology
TM 1
; otherwise, don't enable.
TM
9