Chapter 6 Wireless LAN

 

 

 

 

Table 10 Wireless LAN > Wireless Settings: Root AP (continued)

 

LABEL

DESCRIPTION

 

Advanced Settings

 

 

 

 

 

Beacon Interval

When a wirelessly network device sends a beacon, it includes with it a beacon interval.

 

 

This specifies the time period before the device sends the beacon again. The interval tells

 

 

receiving devices on the network how long they can wait in lowpower mode before waking

 

 

up to handle the beacon. A high value helps save current consumption of the access point.

 

 

 

 

DTIM Interval

Delivery Traffic Indication Message (DTIM) is the time period after which broadcast and

 

 

multicast packets are transmitted to mobile clients in the Active Power Management

 

 

mode. A high DTIM value can cause clients to lose connectivity with the network.

 

 

 

 

Output Power

Set the output power of the NWA1121-NI in this field. If there is a high density of APs in

 

 

an area, decrease the output power of the NWA1121-NI to reduce interference with other

 

 

APs. Select one of the following Full (Full Power), 50%, 25%, or 12.5%. See the

 

 

product specifications for more information on your NWA1121-NI’s output power.

 

 

 

 

Preamble Type

Select Dynamic to have the AP automatically use short preamble when wireless adapters

 

 

support it, otherwise the AP uses long preamble.

 

 

Select Long if you are unsure what preamble mode the wireless adapters support, and to

 

 

provide more reliable communications in busy wireless networks.

 

 

 

 

RTS/CTS

(Request To Send) The threshold (number of bytes) for enabling RTS/CTS handshake.

 

Threshold

Data with its frame size larger than this value will perform the RTS/CTS handshake.

 

 

Setting this attribute to be larger than the maximum MSDU (MAC service data unit) size

 

 

turns off the RTS/CTS handshake. Setting this attribute to its smallest value (1) turns on

 

 

the RTS/CTS handshake.

 

 

 

 

Fragmentation

The threshold (number of bytes) for the fragmentation boundary for directed messages. It

 

 

is the maximum data fragment size that can be sent.

 

 

 

 

Extension

You can use CTS to self or RTS-CTSprotection mechanism to reduce conflicts with other

 

Channel

wireless networks or hidden wireless clients. The throughput of RTS-CTSis much lower

 

Protection Mode

than CTS to self. Using this mode may decrease your wireless performance.

 

 

 

 

A-MPDU

This field is available only when 802.11 b/g/n is selected as the Wireless Mode.

 

Aggregation

Select to enable A-MPDU aggregation.

 

 

 

 

Message Protocol Data Unit (MPDU) aggregation collects Ethernet frames along with their

 

 

802.11n headers and wraps them in a 802.11n MAC header. This method is useful for

 

 

increasing bandwidth throughput in environments that are prone to high error rates.

 

 

 

 

Short GI

This field is available only when 802.11 b/g/n is selected as the Wireless Mode. Select

 

 

Enabled to use Short GI (Guard Interval). The guard interval is the gap introduced

 

 

between data transmission from users in order to reduce interference. Reducing the GI

 

 

increases data transfer rates but also increases interference. Increasing the GI reduces

 

 

data transfer rates but also reduces interference.

 

 

 

 

MCS Rate

The MCS Rate table is available only when 802.11 b/g/n is selected in the Wireless

 

 

Mode field.

 

 

IEEE 802.11n supports many different data rates which are called MCS rates. MCS stands

 

 

for Modulation and Coding Scheme. This is an 802.11n feature that increases the wireless

 

 

network performance in terms of throughput.

 

 

For each MCS Rate (0-15), select either Enabled to have the NWA1121-NI use the data

 

 

rate.

 

 

Clear the Enabled check box if you do not want the NWA1121-NI to use the data rate.

 

 

Turn on the Auto option to have the NWA1121-NI set the data rates automatically to

 

 

optimize the throughput.

 

 

Note: You can set the NWA1121-NI to use up to four MCS rates at a time.

 

 

 

 

Apply

Click Apply to save your changes.

 

 

 

 

Cancel

Click Cancel to begin configuring this screen afresh.

 

 

 

 

63

NWA1121-NI User’s Guide