C H A P T E R 5
Wireless Settings Screen
5.1 Overview
This chapter discusses the steps to configure the Wireless Settings screen on the NWA. It also introduces the wireless LAN (WLAN) and some basic scenarios.
Figure 18
Wireless Mode
In the figure above, the NWA allows access to another bridge device (A) and a notebook computer
(B) upon verifying their settings and credentials. It denies access to other devices (C and D) with configurations that do not match those specified in your NWA.
5.2 What You Can Do in this Chapter
Use the Wireless > Wireless Settings screen to configure the NWA’s operation mode (see
Section 5.4 on page 50 ).
NWA1100-N User’s Guide 48
Chapter 5 Wireless Settings Screen
5.3 What You Need To Know
BSS
A Basic Service Set (BSS) exists when all communications between wireless clients or between a wireless client and a wired network client go through one access point (AP). Intra-BSS traffic is traffic between wireless clients in the BSS.
ESS
An Extended Service Set (ESS) consists of a series of overlapping BSSs, each containing an access point, with each access point connected together by a wired network. This wired connection between APs is called a Distribution System (DS).
Operating Mode
The NWA can run in four operating modes as follows:
• Access Point. The NWA is wireless access point that allows wireless communication to other devices in the network.
• Bridge/Repeater. The NWA acts as a wireless network bridge and establishes wireless links with other APs. You need to know the MAC address of the peer device, which also must be in bridge mode. The NWA can establish up to five wireless links with other APs.
• AP+Bridge. The NWA functions as a bridge and access point simultaneously.
• Wireless Client. The NWA acts as a wireless client to access a wireless network.
• Multi SSID. This mode allows you to use one access point to provide several BSSs simultaneously.
Refer to
Chapter 1 on page 11
for illustrations of these wireless applications.
SSID
The SSID (Service Set IDentifier) identifies the Service Set with which a wireless station is associated. Wireless stations associating to the access point (AP) must have the same SSID.
Normally, the NWA acts like a beacon and regularly broadcasts the SSID in the area. You can hide the SSID instead, in which case the NWA does not broadcast the SSID. In addition, you should change the default SSID to something that is difficult to guess.
This type of security is fairly weak, however, because there are ways for unauthorized wireless devices to get the SSID. In addition, unauthorized wireless devices can still see the information that is sent in the wireless network.
Channel
A channel is the radio frequency(ies) used by IEEE 802.11a/b/g wireless devices. Channels available depend on your geographical area. You may have a choice of channels (for your region) so you should use a different channel than an adjacent AP (access point) to reduce interference.
NWA1100-N User’s Guide 49
Chapter 5 Wireless Settings Screen
Wireless Mode
The IEEE 802.1x standard was designed to extend the features of IEEE 802.11 to support extended authentication as well as providing additional accounting and control features. Your NWA can support 802.11b/g and 802.11b/g/n.
Multi SSID
Traditionally, you needed to use different APs to configure different Basic Service Sets (BSSs). As well as the cost of buying extra APs, there was also the possibility of channel interference. The
NWA’s multi-SSID function allows you to use one access point to provide several BSSs simultaneously. You can then assign varying levels of privilege to different SSIDs.
Wireless stations can use different SSIDs to associate with the same AP.
The following are some notes on multiple SSIDs.
• A maximum of four BSSs are allowed on one AP simultaneously.
• You must use different security settings for different BSSs. If two stations have different BSSIDs
(they are in different BSSs), but have the same security settings, they may hear each other’s communications (but not communicate with each other).
• Multi-SSID should not replace but rather be used in conjunction with 802.1x security.
5.4 Wireless Settings Screen
Use this screen to choose the operating mode for your NWA. Click Wireless > Wireless Settings.
The screen varies depending upon the operating mode you select.
50 NWA1100-N User’s Guide
Chapter 5 Wireless Settings Screen
5.4.1 Access Point Mode
Use this screen to use your NWA as an access point. Select Access Point as the Operation Mode.
The following screen displays.
Figure 19
Wireless > Wireless Settings: Access Point
The following table describes the general wireless LAN labels in this screen.
Table 4
Wireless > Wireless Settings: Access Point
LABEL
Basic Settings
Disable Wireless
LAN Interface
Operation Mode
DESCRIPTION
Select this option to turn off the wireless LAN.
Select Access Point from the drop-down list.
NWA1100-N User’s Guide 51
Chapter 5 Wireless Settings Screen
Table 4
Wireless > Wireless Settings: Access Point (continued)
LABEL
Wireless Mode
DESCRIPTION
Select 802.11b/g to allow both IEEE802.11b and IEEE802.11g compliant WLAN devices to associate with the NWA. The transmission rate of your NWA might be reduced.
SSID Profile
Select 802.11b/g/n to allow IEEE802.11b, IEEE802.11g and IEEE802.11n compliant
WLAN devices to associate with the Device. The transmission rate of the NWA might be reduced.
The SSID (Service Set IDentifier) identifies the Service Set with which a wireless station is associated. Wireless stations associating to the access point (AP) must have the same
SSID. Select an SSID Profile from the drop-down list box.
Channel
Channel Width
Note: If you are configuring the NWA from a computer connected to the wireless LAN and you change the NWA’s SSID or security settings, you will lose your wireless connection when you press Apply to confirm. You must then change the wireless settings of your computer to match the NWA’s new settings.
Select the operating frequency/channel depending on your particular region from the drop-down list box.
This field displays only when you select 802.11 b/g/n in the 802.11 Wireless Mode field.
A standard 20MHz channel offers transfer speeds of up to 150Mbps whereas a 40MHz channel uses two standard channels and offers speeds of up to 300Mbps. However, not all devices support 40MHz channels.
Select the channel bandwidth you want to use for your wireless network.
It is recommended that you select 20/40 (20/40 MHz). This allows the NWA to adjust the channel bandwidth depending on network conditions.
Select 20 MHz if you want to lessen radio interference with other wireless devices in your neighborhood.
Advanced Settings
Click + or - to display or hide the following fields.
Beacon Interval
DTIM Interval
Output Power
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.
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.
Set the output power of the NWA in this field. If there is a high density of APs in an area, decrease the output power of the NWA to reduce interference with other APs. Select one of the following Full (Full Power), 50%, 25%, 12.5% or Min (Minimum). See the product specifications for more information on your NWA’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.
RTS/CTS
Threshold
Fragmentation
Select Long if you are unsure what preamble mode the wireless adapters support, and to provide more reliable communications in busy wireless networks.
(Request To Send) The threshold (number of bytes) for enabling RTS/CTS handshake.
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.
The threshold (number of bytes) for the fragmentation boundary for directed messages. It is the maximum data fragment size that can be sent.
52 NWA1100-N User’s Guide
Chapter 5 Wireless Settings Screen
Table 4
Wireless > Wireless Settings: Access Point (continued)
LABEL
A-MPDU aggregation
Short GI
Rates
Configuration
DESCRIPTION
This field is available only when 802.11 b/g/n is selected as the Wireless Mode. Select
Enable to allow the grouping of several A-MSDUs (Aggregate MAC Service Data Units) into one large A-MPDU (Aggregate MAC Protocol Data Unit). This function allows faster data transfer rates.
This field is available only when 802.11 b/g/n is selected as the Wireless Mode. Select
Enable 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.
This section controls the data rates permitted for clients.
MCS Table
Apply
Cancel
For each Rate, select an option from the Configuration list. The options are:
• Basic (1~11 Mbps only): Clients can always connect to the access point at this speed.
• Optional: Clients can connect to the access point at this speed, when permitted to do so by the AP.
• Disable: Clients cannot connect to the access point at this speed.
The MCS Rate table is available only when 802.11 b/g/n is selected in the 802.11
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 Enable (default) to have the NWA use the data rate. Select Disable if you do not want the NWA to use the data rate.
Click Apply to save your changes.
Click Cancel to begin configuring this screen afresh.
5.4.2 Bridge / Repeater Mode
Use this screen to have the NWA act as a wireless network bridge and establish wireless links with other APs. You need to know the MAC address of the peer device, which also must be in bridge mode.
NWA1100-N User’s Guide 53
Chapter 5 Wireless Settings Screen
Use this screen to use the NWA as a wireless bridge. Select Bridge/Repeater as the Operation
Mode.
Figure 20
Wireless > Wireless Settings: Bridge/Repeater
54 NWA1100-N User’s Guide
Chapter 5 Wireless Settings Screen
The following table describes the bridge labels in this screen.
Table 5
Wireless > Wireless Settings: Bridge/Repeater
LABEL
Basic Settings
Disable Wireless LAN
Interface
Operation Mode
Wireless Mode
DESCRIPTIONS
Select this option to turn off the wireless LAN.
Channel
Channel Width
Select Bridge/Repeater in this field.
Select 802.11b/g to allow both IEEE802.11b and IEEE802.11g compliant WLAN devices to associate with the NWA. The transmission rate of your NWA might be reduced.
Select 802.11b/g/n to allow IEEE802.11b, IEEE802.11g and IEEE802.11n compliant
WLAN devices to associate with the NWA. The transmission rate of the NWA might be reduced.
Select the operating frequency/channel depending on your particular region from the drop-down list box.
This field displays only when you select 802.11 b/g/n in the 802.11 Wireless Mode field.
A standard 20MHz channel offers transfer speeds of up to 150Mbps whereas a 40MHz channel uses two standard channels and offers speeds of up to 300Mbps. However, not all devices support 40MHz channels.
Select the channel bandwidth you want to use for your wireless network.
It is recommended that you select 20/40 (20/40 MHz). This allows the NWA to adjust the channel bandwidth depending on network conditions.
Select 20 MHz if you want to lessen radio interference with other wireless devices in your neighborhood.
WDS Settings
Local Mac Address
Remote MAC
Address 1 - 4
A Wireless Distribution System is a wireless connection between two or more APs.
Note: WDS security is independent of the security settings between the NWA and any wireless clients.
Local MAC Address is the MAC address of your NWA. You can specify up to 4 remote devices’ MAC addresses in this section.
Enable WDS Security Select this to turn on security for the NWA’s Wireless Distribution System (WDS). A
Wireless Distribution System is a wireless connection between two or more APs. If you do not select the check box, traffic between APs is not encrypted.
Note: WDS security is independent of the security settings between the NWA and any wireless clients.
When you enable WDS security, also do the following:
• Select the type of security you want to use (TKIP or AES) to secure traffic on your
WDS.
• Enter a pre-shared key (PSK) for access point(s) in your WDS.
• Configure WDS security and the relevant PSK in each of your other access point(s).
Note: Other APs must use the same encryption method to enable WDS security.
NWA1100-N User’s Guide 55
Chapter 5 Wireless Settings Screen
Table 5
Wireless > Wireless Settings: Bridge/Repeater (continued)
LABEL
Encryption Type
DESCRIPTIONS
This field is configurable only when you select Enable WDS Security.
Select TKIP to enable Temporal Key Integrity Protocol (TKIP) security on your WDS.
This option is compatible with other ZyXEL access points that support WDS security.
Use this if the other access points on your network support WDS security but do not have an AES option.
Note: Check your other AP’s documentation to make sure it supports WDS security.
Encryption Key
Select AES to enable Advanced Encryption System (AES) security on your WDS. AES provides superior security to TKIP. Use AES if the other access points on your network support it for the WDS.
Type a pre-shared key (PSK) from 8 to 63 case-sensitive ASCII characters (including spaces and symbols). You must also set the peer device to use the same pre-shared key.
Advanced Settings
Click + or - to display or hide the following fields.
Output Power Set the output power of the NWA in this field. If there is a high density of APs in an area, decrease the output power of the NWA to reduce interference with other APs.
Select one of the following Full (Full Power), 50%, 25%, 12.5% or Min (Minimum).
See the product specifications for more information on your NWA’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.
RTS/CTS Threshold
Fragmentation
(Request To Send) The threshold (number of bytes) for enabling RTS/CTS handshake.
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.
The threshold (number of bytes) for the fragmentation boundary for directed messages. It is the maximum data fragment size that can be sent.
A-MPDU aggregation This field is available only when 802.11 b/g/n is selected as the Wireless Mode.
Select Enable to allow the grouping of several A-MSDUs (Aggregate MAC Service Data
Units) into one large A-MPDU (Aggregate MAC Protocol Data Unit). This function allows faster data transfer rates.
Short GI
Select Long if you are unsure what preamble mode the wireless adapters support, and to provide more reliable communications in busy wireless networks.
Rates Configuration
This field is available only when 802.11 b/g/n is selected as the Wireless Mode.
Select Enable 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.
This section controls the data rates permitted for clients.
For each Rate, select an option from the Configuration list. The options are:
• Basic (1~11 Mbps only): Clients can always connect to the access point at this speed.
• Optional: Clients can connect to the access point at this speed, when permitted to do so by the AP.
• Disable: Clients cannot connect to the access point at this speed.
56 NWA1100-N User’s Guide
Chapter 5 Wireless Settings Screen
Table 5
Wireless > Wireless Settings: Bridge/Repeater (continued)
LABEL
MCS Table
DESCRIPTIONS
The MCS Rate table is available only when 802.11 b/g/n is selected in the 802.11
Wireless Mode field.
Apply
Cancel
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 Enable (default) to have the NWA use the data rate. Select Disable if you do not want the NWA to use the data rate.
Click Apply to save your changes.
Click Cancel to begin configuring this screen afresh.
NWA1100-N User’s Guide 57
Chapter 5 Wireless Settings Screen
5.4.3 AP + Bridge Mode
Use this screen to have the NWA function as a bridge and access point simultaneously. Select
AP+Bridge as the Operation Mode. The following screen displays.
Figure 21
Wireless > Wireless Settings: AP+Bridge
58
See the tables describing the fields in the Access Point and Bridge / Repeater operating modes for descriptions of the fields in this screen.
NWA1100-N User’s Guide
Chapter 5 Wireless Settings Screen
5.4.4 Wireless Client Mode
Use this screen to turn your NWA into a wireless client. Select Wireless Client as the Operation
Mode. The following screen displays.
Figure 22
Wireless > Wireless Settings: Wireless Client
The following table describes the general wireless LAN labels in this screen.
Table 6
Wireless > Wireless Settings: Wireless Client
LABEL
Basic Settings
Disable Wireless
LAN Interface
Operation Mode
Site Survey
DESCRIPTION
Select this option to turn off the wireless LAN.
Select Wireless Client in this field.
Click this to view a list of available wireless access points within the range. Select the AP you want to use and click Selected.
SSID Profile
Channel
Note: After selecting Wireless Client as the Operation Mode in the Basic Settings section, you must click Apply to be able to select from the AP list.
Select an SSID Profile from the drop-down list box. The SSID profile defines the SSID and security settings you want to use to set up a wireless network or connect to a wireless device.
This shows the operating frequency/channel in use. This field is read-only when you select
Wireless Client as your operation mode.
Advanced Settings
MAC Clone
Output Power
Choose Manual to configure the NWA’s MAC address by cloning the MAC address from a computer on your LAN. Choose Auto to use the factory default MAC address of your NWA.
Set the output power of the NWA in this field. If there is a high density of APs in an area, decrease the output power of the NWA to reduce interference with other APs. Select one of the following Full (Full Power), 50%, 25%, 12.5% or Min (Minimum). See the product specifications for more information on your NWA’s output power.
NWA1100-N User’s Guide 59
Chapter 5 Wireless Settings Screen
Table 6
Wireless > Wireless Settings: Wireless Client (continued)
LABEL
Preamble Type
DESCRIPTION
Select Dynamic to have the NWA automatically use short preamble when the wireless network your NWA is connected to supports it, otherwise the NWA uses long preamble.
RTS/CTS
Threshold
Extension channel protection mode
A-MPDU aggregation
Short GI
Apply
Cancel
Select Long preamble if you are unsure what preamble mode the wireless device your
NWA is connected to supports, and to provide more reliable communications in busy wireless networks.
(Request To Send) The threshold (number of bytes) for enabling RTS/CTS handshake.
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.
You can use CTS to self or RTS-CTS protection mechanism to reduce conflicts with other wireless networks or hidden wireless clients. The throughput of RTS-CTS is much lower than CTS to self. Using this mode may decrease your wireless performance.
This field is available only when 802.11 b/g/n is selected as the Wireless Mode. Select
Enable to allow the grouping of several A-MSDUs (Aggregate MAC Service Data Units) into one large A-MPDU (Aggregate MAC Protocol Data Unit). This function allows faster data transfer rates.
This field is available only when 802.11 b/g/n is selected as the Wireless Mode. Select
Enable 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.
Click Apply to save your changes.
Click Cancel to begin configuring this screen afresh.
60 NWA1100-N User’s Guide
Chapter 5 Wireless Settings Screen
5.4.5 Multi SSID Mode
Use this screen to have the NWA function in Multi SSID mode. Select Multi SSID as the
Operating Mode. The following screen diplays.
Figure 23
Wireless > Wireless Settings: Multi SSID
NWA1100-N User’s Guide 61
Chapter 5 Wireless Settings Screen
The following table describes the labels in this screen.
Table 7
Wireless > Wireless Settings: Multi SSID
LABEL DESCRIPTION
Select this option to turn off the wireless LAN.
Disable Wireless LAN
Interface
Operating Mode
Wireless Mode
Select Multi SSID in this field.
Select 802.11b/g to allow both IEEE802.11b and IEEE802.11g compliant WLAN devices to associate with the NWA. The transmission rate of your NWA might be reduced.
Channel
Channel Width
Select 802.11b/g/n to allow IEEE802.11b, IEEE802.11g and IEEE802.11n compliant WLAN devices to associate with the NWA. The transmission rate of the NWA might be reduced.
Select the operating frequency/channel depending on your particular region from the drop-down list box.
This field displays only when you select 802.11 b/g/n in the 802.11 Wireless
Mode field.
Select SSID Profile
Index
Active
Profile
Tag
VLAN
A standard 20MHz channel offers transfer speeds of up to 150Mbps whereas a 40MHz channel uses two standard channels and offers speeds of up to 300Mbps. However, not all devices support 40MHz channels.
Select the channel bandwidth you want to use for your wireless network.
It is recommended that you select 20/40 (20/40 MHz). This allows the NWA to adjust the channel bandwidth depending on network conditions.
Select 20 MHz if you want to lessen radio interference with other wireless devices in your neighborhood.
An SSID profile is the set of parameters relating to one of the NWA’s BSSs. The SSID
(Service Set IDentifier) identifies the Service Set with which a wireless station is associated. Wireless stations associating with the access point (AP) must have the same SSID.
If you are configuring the NWA from a computer connected to the wireless LAN and you change the NWA’s SSID or security settings, you will lose your wireless connection when you press Apply to confirm. You must then change the wireless settings of your computer to match the NWA’s new settings.
Select the check box to activate an SSID profile.
Select the check box to enable the bridge connection. Otherwise, clear the check box to disable it. The first profile is always active.
Select the profile(s) of the SSIDs you want to use in your wireless network. You can have up to four BSSs running on the NWA simultaneously.
Configure SSID profiles in the Multi SSID screen.
This displays whether traffic from this SSID is tagged with the VLAN ID.
This field is configurable only when you enable 802.1Q VLAN tagging in the System >
General screen.
Select the check box to enable VLAN tagging for this SSID.
This displays the VLAN ID associated with the SSID.
This field is configurable only when you enable 802.1Q VLAN tagging in the System >
General screen and select the Tag check box in this screen.
Enter a VLAN ID number from 1 to 4094. Packets coming from the WLAN using this
SSID profile are tagged with the VLAN ID number by the NWA. Different BSSID profiles can use the same or different VLAN IDs. This allows you to split wireless stations into groups using similar VLAN IDs.
62 NWA1100-N User’s Guide
Chapter 5 Wireless Settings Screen
Table 7
Wireless > Wireless Settings: Multi SSID (continued)
LABEL DESCRIPTION
QoS This displays the QoS priority level associated with the SSID.
This field is configurable only when you enable 802.1Q VLAN tagging in the System >
General screen and select the Tag check box in this screen.
Select the Quality of Service priority for this BSS’s traffic.
Advanced Settings
Beacon Interval
DTIM Interval
Output Power
Preamble Type
When a wirelessly networked 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.
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.
Set the output power of the NWA in this field. If there is a high density of APs in an area, decrease the output power of the NWA to reduce interference with other APs.
Select one of the following Full (Full Power), 50%, 25%, 12.5% or Min (Minimum).
See the product specifications for more information on your NWA’s output power.
Select Dynamic to have the AP automatically use short preamble when wireless adapters support it, otherwise the AP uses long preamble.
RTS/CTS Threshold
Extension channel protection mode
You can use CTS to self or RTS-CTS protection mechanism to reduce conflicts with other wireless networks or hidden wireless clients. The throughput of RTS-CTS is much lower than CTS to self. Using this mode may decrease your wireless performance.
A-MPDU aggregation This field is available only when 802.11 b/g/n is selected as the Wireless Mode.
Select Enable to allow the grouping of several A-MSDUs (Aggregate MAC Service
Data Units) into one large A-MPDU (Aggregate MAC Protocol Data Unit). This function allows faster data transfer rates.
Short GI
Select Long if you are unsure what preamble mode the wireless adapters support, and to provide more reliable communications in busy wireless networks.
(Request To Send) The threshold (number of bytes) for enabling RTS/CTS handshake.
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.
Rates Configuration
This field is available only when 802.11 b/g/n is selected as the Wireless Mode.
Select Enable 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.
This section controls the data rates permitted for clients.
For each Rate, select an option from the Configuration list. The options are:
• Basic (1~11 Mbps only): Clients can always connect to the access point at this speed.
• Optional: Clients can connect to the access point at this speed, when permitted to do so by the AP.
• Disable: Clients cannot connect to the access point at this speed.
NWA1100-N User’s Guide 63
Chapter 5 Wireless Settings Screen
Table 7
Wireless > Wireless Settings: Multi SSID (continued)
LABEL DESCRIPTION
MCS Table The MCS Rate table is available only when 802.11 b/g/n is selected in the 802.11
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.
Apply
Cancel
For each MCS Rate (0-15), select either Enable (default) to have the NWA use the data rate. Select Disable if you do not want the NWA to use the data rate.
Click Apply to save your changes.
Click Cancel to begin configuring this screen afresh.
5.5 Technical Reference
This section provides technical background information about the topics covered in this chapter.
Refer to
Appendix D on page 177 for further readings on Wireless LAN.
5.5.1 WMM QoS
WMM (Wi-Fi MultiMedia) QoS (Quality of Service) ensures quality of service in wireless networks. It controls WLAN transmission priority on packets to be transmitted over the wireless network.
WMM QoS prioritizes wireless traffic according to the delivery requirements of the individual and applications. WMM QoS is a part of the IEEE 802.11e QoS enhancement to certified Wi-Fi wireless networks.
On APs without WMM QoS, all traffic streams are given the same access priority to the wireless network. If the introduction of another traffic stream creates a data transmission demand that exceeds the current network capacity, then the new traffic stream reduces the throughput of the other traffic streams.
The NWA uses WMM QoS to prioritize traffic streams according to the IEEE 802.1q or DSCP information in each packet’s header. The NWA automatically determines the priority to use for an individual traffic stream. This prevents reductions in data transmission for applications that are sensitive to latency and jitter (variations in delay).
64 NWA1100-N User’s Guide
Chapter 5 Wireless Settings Screen
5.5.2 Additional Wireless Terms
Table 8
Additional Wireless Terms
TERM
Intra-BSS Traffic
RTS/CTS Threshold
Preamble
Fragmentation
Threshold
Roaming
Antenna
DESCRIPTION
This describes direct communication (not through the NWA) between two wireless devices within a wireless network. You might disable this kind of communication to enhance security within your wireless network.
In a wireless network which covers a large area, wireless devices are sometimes not aware of each other’s presence. This may cause them to send information to the AP at the same time and result in information colliding and not getting through.
By setting this value lower than the default value, the wireless devices must sometimes get permission to send information to the NWA. The lower the value, the more often the devices must get permission.
If this value is greater than the fragmentation threshold value (see below), then wireless devices never have to get permission to send information to the NWA.
A preamble affects the timing in your wireless network. There are two preamble modes: long and short.
If a device uses a different preamble mode than the NWA does, it cannot communicate with the NWA.
A small fragmentation threshold is recommended for busy networks, while a larger threshold provides faster performance if the network is not very busy.
If you have two or more NWAs (or other wireless access points) on your wireless network, you can enable this option so that wireless devices can change locations without having to log in again. This is useful for devices, such as notebooks, that move around a lot.
An antenna couples Radio Frequency (RF) signals onto air. A transmitter within a wireless device sends an RF signal to the antenna, which propagates the signal through the air. The antenna also operates in reverse by capturing RF signals from the air.
Positioning the antennas properly increases the range and coverage area of a wireless
LAN.
NWA1100-N User’s Guide 65
