802.11g Wireless LAN Adapter

Turbo Mode

Wireless LAN USB Adapter
USB 2.0, WPA/WPA2 Compliant

EW-7318Ug

Features :
Taiwan / Headquarters Edimax Technology Co., LTD. TEL:886-2-7739-6888 FAX:886-2-7739-6887 sales@edimax.com.tw China Beijing Edimax Science & Technology Co., LTD. TEL:8610-6213-9288 FAX:8610-6213-9231 sales@edimax.com.cn Europe Edimax Technology Europe B.V. TEL:31-499-377344 FAX:31-499-372647 sales@edimax.nl Latin America TEL:1-786-845-8099 FAX:1-786-331-8490 sales_latinamerica@edimax.com Poland Edimax Technology Europe B.V. SP. Z O.O. Tel: +48(22)-6060-255 Fax: +48(22)-6060-254 sales@edimax.nl U.S.A. Edimax Computer Company TEL:1-408-496-1105 FAX:1-408-980-1530 sales@edimax.com U.K. Edimax Technology (UK) Ltd. TEL:44-870-7740226 FAX:44-870-7740227 info@edimax.co.uk
Complies with the IEEE 802.11b and IEEE 802.11g 2.4GHz (DSSS) standards. High data transfer rate - up to 54Mbps. Supports Turbo Mode to enhance the data transfer speed within the specific wireless network. Supports WMM function to meet the multi-media data bandwidth requirement. Supports 64/128-bit WEP, WPA (TKIP with IEEE 802.1x), WPA2 (AES with IEEE 802.1x) functions for high level of security. Supports the most popular operating system: Windows98 SE/Me/2000/XP. Supports USB 2.0/1.1/1.0 interface, portable and mini-size design.

Specification :

Product Standards Bus Type Frequency Band Modulation Data Rate Securities Antenna Drivers LEDs Transmit Power Receive Sensitivity Dimension Temperature Humidity Certification 802.11g Turbo Wireless LAN USB Adapter IEEE 802.11g/b USB 2.0 Type A 2.4000~2.4835GHz (Industrial Scientific Medical Band) OFDM with BPSK, QPSK, 16QAM, 64QAM (11g) BPSK, QPSK, CCK (11b) 54/48/36/24/18/12/11/9/6/5.5/2/1Mbps auto fallback 64/128-bit WEP Data Encryption, WPA (TKIP with IEEE 802.1x), WPA2 (AES with IEEE 802.1x) Internal Antenna Windows 98SE/Me/2000/XP/ x64 Edition Link/Activity 17dBm 2dBm -70dBm@54Mbps, -83.5dBm@11Mbps 9(H) x 27(W) x 87(D) mm 32~122F (0 ~50C) 10-95% (NonCondensing) FCC , CE

1-3 System Requirements

EW-7318USg/EW-7318Ug/EW-7718Un/EW-7717Un An empty USB 2.0 port (May not work on USB 1.1 port, and performance will be greatly reduced) Windows 2000, 2003, XP, or Vista operating system CD-ROM drive At least 100MB of available disk space EW-7108PCg/EW-7708Pn An empty PCMCIA type II slot (CardBus Compatible) Operation System: Windows 2000, XP, XP64, or Vista CD-ROM drive At least 100MB of available disk space EW-7128g/EW-7727In/EW-7728In An empty PCI slot Windows 2000, 2003, XP, or Vista operating system CD-ROM drive At least 100MB of available disk space EW-7738Pn An empty PCIe ExpressCard slot Windows 2000, 2003, XP, or Vista operating system CD-ROM drive At least 100MB of available disk space EW-7748In An empty PCIe slot Windows 2000, 2003, XP, or Vista operating system CD-ROM drive At least 100MB of available disk space

1-4 Package Contents

Before you starting to use this wireless network card, please check if there's anything missing in the package, and contact your dealer of purchase to claim for missing items:
EW-7318Ug / EW-7718Un / EW-7717Un USB wireless adapter with Protection Cap (1 pcs) USB Cable with Stand (1 pcs) Quick installation guide (1 pcs) User Guides / EZMAX Setup Wizard & driver CDROM (1 pcs)
EW-7318USg USB wireless adapter with Protection Cap (1 pcs) USB Cable with Stand (1 pcs) Antenna (1 pcs). Quick installation guide (1 pcs) User Guides / EZMAX Setup Wizard & driver CDROM (1 pcs)
EW-7128g Wireless network PCI card (1 pcs) Antenna (1 pcs). Quick installation guide (1 pcs) User Guides / EZMAX Setup Wizard & driver CDROM (1 pcs)
EW-7727In Wireless network PCI card (1 pcs) Antenna (2 pcs). Quick installation guide (1 pcs) User Guides / EZMAX Setup Wizard & driver CDROM (1 pcs)
EW-7728In Wireless network PCI card (1 pcs) Antenna (3 pcs). Quick installation guide (1 pcs) User Guides / EZMAX Setup Wizard & driver CDROM (1 pcs)
EW-7748In Wireless network PCIe card (1 pcs) Antenna (3 pcs). Quick installation guide (1 pcs) User Guides / EZMAX Setup Wizard & driver CDROM (1 pcs)
EW-7108PCg / EW-7708Pn Wireless network cardbus (1 pcs) Quick installation guide (1 pcs) User Guides / EZMAX Setup Wizard & driver CDROM (1 pcs) EW-7738Pn Wireless network ExpressCard (1 pcs) Quick installation guide (1 pcs) User Guides / EZMAX Setup Wizard & driver CDROM (1 pcs)
1-5 Familiar with your new wireless network card
EW-7318Ug 1. USB Connector 2. Connector Cap (To protect USB connector when not in use) 3. Link/Activity LED

Please follow the following instructions to install your new USB wireless network card:
EW-7318USg/ EW-7318Ug / EW-7718Un / EW-7717Un 1. Fasten the antennas to the antenna connectors on the network card by clockwise direction. (EW-7318USg only) 2. Insert the USB wireless network card into an empty USB 2.0 port of your computer when computer is switched on. Never use force to insert the card, if you feel its stuck, flip the card over and try again. 3. The following message will appear on your computer, click Cancel.

EW-7128g/ EW-7727In/

EW-7728In / EW-7748In
1. SWITCH THE COMPUTER OFF, remove the cover and insert the wireless network card into an empty PCI slot (EW-7128g/EW-7728In) or PCIe slot (EW-7748In) of your computer. 2. Fasten the antennas to the antenna connectors on the network card by clockwise direction. 3. You can bend the antenna to fit actual needs. 4. To improve radio reception, please adjust antennas to the position shown in the picture. 5. Switch the computer on, the following message will appear on your computer, please click cancel.
EW-7108PCg/ EW-7708Pn / EW-7738Pn 1. Please insert the wireless network card into an empty PCMCIA slot (EW-7108PCg/EW-7708Pn) or ExpressCard slot (EW-7738Pn) of your computer. You can insert the card when the computer is power off or on Dont use force to insert the card into PCMCIA or PCIe ExpressCard slot; if you feel it get stuck, remove it and flip the card upside down, and then try again 2. The following message will appear on your computer, click Cancel.
2-2 Software Installation
This wizard can be run in Windows 2000/XP/Vista. The following procedures are operated in Windows XP. You can install the Wireless Adapter by EZMAX Setup Wizard in the CD-ROM including in the package. The wizard is an easy and quick configuration tool for internet connection with series process. When you start EZMAX Setup Wizard, you will get the following welcome screen. Please choose the language to start the configuration. The wizard will guide you to finish your network connection. We will not provide any instruction for the EZMAX Setup Wizard here.

If you lose the CD ROM or you prefer the traditional setup procedure, please follow the instruction as following step in this quick installation guide.
2.2.1 Please execute Edimax_xxxx_Setup.exe program to install your wireless adapter. Please read the end user license agreement and click I accept the terms of the license agreement and Next to accept license agreement.
2.2.2 You can choose the configuration tool used to configure the wireless network card here. Its recommended to select Edimax Configuration Tool, which provides fully access to all function of this wireless network card. If you prefer to use the wireless configuration tool provided by Windows XP or Vista, please select Microsoft Zero Configuration Tool, and then click Next.
2.2.3 Please select Optimize for WiFi mode for wireless compatibility, then click Next. If you want to enhance wireless performance, please select Optimize for performance mode. However, wireless compatibility is not guaranteed in this mode. Please refer to user manual for details of performance mode.
2.2.4 When you see this message, please click Finish to complete the driver installation process.
2-3 Connect to Wireless Access Point
After the driver is correctly installed, it will try to connect to any unencrypted wireless access point automatically. If you want to connect to a specific wireless access point, or the access point you wish to connect uses encryption, you have to configure the wireless network card and input required parameters, to get connected to the wireless access point you wish to connect. There are two ways you can configure your wireless network card to connect to wireless access point: using the Edimax configuration utility which comes with wireless card driver, and using built-in windows zero configuration utility. 2-3-1Using Edimax Wireless Utility Please follow the following instructions to use Edimax configuration utility to connect to wireless access point. 1. Right-click the Edimax configuration utility icon located at lower-right corner of computer desktop, then click Launch Config Utilities.

7. If you can see Connected message, the connection between your computer and wireless access point is successfully established.
2-4 Connection Profile Management
If you need to connect to different wireless access points at different time, like of access point of your home, office, cybercafe, or public wireless service, you can store the connection parameters (encryption, passphrase, security etc, etc.) as a profile for every access point, so you dont have in input these parameters every time you want to connect to a specific wireless access point. 2-4-1 Make a profile for an access point or wireless device 1. Right-click the Edimax configuration utility icon located at lower-right corner of computer desktop, then click Launch Config Utilities.
2. There are two ways to add a new connection profile: Create a new profile,orAdd a profile from an existing wireless access point or wireless device If you want to click new profile, click Profile tab, then click Add button:
Or, you can add a connected wireless access point or wireless device to a profile by clicking Site Survey tab, then click Add to Profile button:
And you can set the parameter for this connection here:
Here are descriptions of every setup items: Profile Name Please give this profile a name, up to 32 alphanumerical characters and symbols are allowed, but space is not allowed. SSID The SSID of the wireless access point or wireless device you selected will be displayed here. But if the SSID of access point or wireless device is not available, you have to input it here manually. Please select CAM (constantly awake mode, keep the wireless radio activity when not transferring data), or PSM (Power saving mode, switches radio off when not transferring data).

PSM: (Power Saving Mode)

Its recommended to choose PSM if youre using this network card with notebook computer to help the battery live longer. Network Type Select network type (Ad Hoc or Infrastructure). If youre adding a profile from an existing access point or wireless device, its automatically selected and you dont have to change it. This option is only available when the network type is Ad hoc. You can select Auto or Long Preamble. Please select Auto if you dont know what it is. Check the box and you can set RTS threshold manually here. Do not modify default setting unless you know what it is. Check the box and you can set fragment threshold manually here. Do not modify default setting unless you know what it is.

Preamble

RTS Threshold

Fragment Threshold

Now click Authentication and Security tab, and set the encryption and authentication settings.

Input the server name of CA server here. Check this box and the wireless configuration utility will check if the server name of CA server you set here is exactly matched with the CA server connected to. If they dont match, connection will be dropped.

Domain name

Check this box and the wireless configuration utility must end will check the end of domain name. If theres in specified name anything wrong, connection will be dropped. After you finish all settings, click OK to save settings and exit.
2-5 View Network Statistics and Link Status
The configuration utility provides information about network statistics and link status. If you want to know how your wireless network card works, you can use these functions to get detailed information about the wireless connection youre using. 2-5-1 Network Statistics Please follow the following instructions to check network statistics: 1. Right-click the Edimax configuration utility icon located at lower-right corner of computer desktop, then click Launch Config Utilities.
2. Click Statistics tab, and the statistics of wireless connection will be displayed:
All connection-related statistics is displayed here. You can click Reset Counter to reset the statistics of all items back to 0. Click OK to close the window.
2-5-2 Link Status Please follow the following instructions to check network statistics: 1. Right-click the Edimax configuration utility icon located at lower-right corner of computer desktop, then click Launch Config Utilities.
2. Click Link Status tab, and information about current wireless connection will be displayed:
These information displayed here are updated every second, and here are descriptions of every item: Status Displays the SSID and BSSID of connected wireless access point or wireless device (displayed as SSID <-> BSSID as shown in above picture. If theres no active connection currently, Disconnected will be displayed here. Displays the link status (Link is up or Link is down, and the radio transmitting power of your network card. Displays the radio channel being used now. Displays the link speed of data transmitting (Tx, in Mbps) and receiving (Rx, in Mbps). Link speed is the maximum available data transfer speed of the wireless connection, and depends on the radio signal quality of wireless connection. Displays the rate of data transmitting (Tx, in Kbps) and receiving (Rx, in Kbps). Displays link quality (radio signal quality). When the link quality is better, the wireless link speed will be better, too. Link quality is displayed by percentage and a descriptive word (Good, normal, weak, and low).

Extra Info

Channel Link Speed

Throughput

Link Quality
Signal Strength 1 Displays the radio signal strength of built-in antenna 1. Signal Strength 2 Displays the radio signal strength of built-in antenna 2.

Noise Level

Displays the percentage or level of noise (unusable) signal. If the value of this item is high, data transfer rate will drop. Check this box and the value of signal strength and noise level will be displayed in dBm level instead of percentage.
There are several wireless statuses available at the bottom of this window. For their explanations, please see chapter 4-3 Glossary.

2-6 Advanced Settings

This wireless network card provides several advanced settings for experienced wireless users. You can change these settings to increase data transfer performance, or change operation mode. Please follow the following instructions to set advanced wireless settings: 1. Right-click the Edimax configuration utility icon located at lower-right corner of computer desktop, then click Launch Config Utilities.
2. Click Advanced tab, and the following settings will appear:
Here are descriptions of every setup items: Wireless mode Select wireless operation mode, available options are 802.11 B/G mix, 802.11 B only, and 802.11 B/G/N mix. You can select 802.11 B/G/N mix to maximize wireless compatibility with wireless access points and other wireless devices. Anyway, you can set this setting to 802.11 B only when youre going to communicate with old 802.11b wireless devices and you got problem using other two modes. Wireless Protection This setting helps your network card to avoid interference with other wireless devices when there are both 802.11b and 802.11g wireless devices in the same place. Its recommended to set this setting to Auto , since enabling this setting will slightly reduce the data transfer performance. Normally, the wireless network card will adjust transfer rate automatically according to wireless signal quality. However, you can fix the data transfer rate to a lower fixed rate if you think theres some problem about data transfer, or youre too far from wireless access point. Its recommended to set this setting to Auto, unless you really know the meaning of this setting. Check this box to accelerate the data transmit rate. It may not work with all wireless access point and wireless devices. Check this box and the configuration utility will adjust TCP window size automatically, to get better performance. It should be safe for most of wireless environments, but if you found some problem on data transfer, uncheck this box.

TX Rate

Tx BURST

Enable TCP Window Size

Fast Roaming at
Check this box and you can adjust the threshold of when this wireless network card should switch to another wireless access point with better signal quality. Only adjust value when you understand what it means. Click this button to switch wireless radio off, click itagain switch wireless radio on. Select the country / region code of the place youre living. Different country / region has different regulations on wireless devices, and its forbidden to use certain channel (radio frequency) in some countries or regions. The operating frequency channel will be restricted to the country / region user located before importing.

Turn off RF

Select Your Country Region Code
Show Authentication Status Dialog
When your computer is being authenticated by wireless authentication server, a dialog window with the process of authentication will appear. This function is helpful to find out the problem when you can not be authenticated, and you can provide this information to authentication servers administrator for debugging purpose. Enable Cisco Compatible eXtensions. CCX is a wireless feature developed by Cisco used to improve the wireless performance with CCX compatible wireless devices. Check this box if you need to connect to CCX-compatible wireless devices.

Enable CCX

Turn on CCKM
Check this box to enable CCKM (Cisco Centralized Key Management), which enables wireless clients to roam between CCKM-enabled access points in very short time. When youre connecting to CCX-compatible access point, check this box to enable radio measurement function to improve wireless connectivity. When youre connecting to CCX-compatible access point, check this box to enable measurement on unused radio channels to improve wireless connectivity. Limit the time used for said measurement to a certain time. Default value is 250.

Enable Radio Measurement

Non-Serving Channel Measurements

Limit --milliseconds

After you finish the settings, click Apply to apply new settings, and click OK to close configuration utility.

2-7 QoS Setting

This wireless network card provides QoS (Quality of Service) function, which can improve the performance of certain network applications, like audio / video streaming, network telephony (VoIP), and others. When you enable WMM (Wi-Fi MultiMedia) function of this network card, you can define the priority of different kinds of data, to give higher priority to applications which require instant responding. Therefore you can improve the performance of such network applications. Please follow the following instructions to set advanced wireless settings: Right-click the Edimax configuration utility icon located at lower-right corner of computer desktop, then click Launch Config Utilities.

2-8-1 WPS Setup - PBC (Push-Button Configuration) 1. Right-click the Edimax configuration utility icon located at lower-right corner of computer desktop, then click Launch Config Utilities.
2. Click WPS Configuration tab, and the following settings will appear:
3. Set Config Mode to Enrollee, and then push the WPS button on your wireless access point (the button used to activate WPS standby mode may have another name), or use other way to start WPS standby mode as the instruction given by your wireless access points user manual. 4. Before you start to establish the wireless connection by using WPS, you can click Rescan button to search for WPS-enabled access points near you, to make sure the WPS function of your access point is activated.
All access points with WPS function enabled will be displayed. Please make sure the access point you wish to connect is displayed. If not, please click Rescan few more times. You can also click Information button to see the detailed information about selected access point.
5. Start PBC pairing procedure at access point side (please refer to the instruction given by your access points manufacturer), then click PBC button in wireless configuration utility to start to establish wireless connection by WPS. Please be patient (This may require several seconds to one minute to complete). When you see WPS status is connected successfully message, means the connection between your wireless network card and access point is successfully connected by WPS, and the information about access point you connected to will be displayed.
Sometime WPS may fail, and you can click PBC button few more times to try again. When an access point is connected, you can click Disconnect to disconnect your wireless network card from a connected access point, or select another WPS-enabled wireless access point, then click Connect to establish connection to selected access point, if there are more than one WPS-enabled access point found. You can also click Rotate button, and next access point on the list will be selected to establish connection. If you want to delete a found access point from the list, select it and click Delete button.
2-8-2 WPS Setup - PIN If the wireless access point you wish to connect supports PIN, please follow the following instructions to establish connection to it: 1. Right-click the Edimax configuration utility icon located at lower-right corner of computer desktop, then click Launch Config Utilities.

The PIN number of your wireless network card is an eight-digit number located at the upper-right position of configuration utility. Remember it, and input the number to your wireless access point as the WPS PIN code (Please refer to the user manual of your wireless access point for instructions about how to do this). NOTE: The PIN code of every wireless network card is DIFFERENT. Please dont use the sample code shown here. 3. Click PIN button now, and wait for few seconds to one minute. If a wireless access point with correct PIN code is found, youll be connected to that access point:
You may have to click PIN for few more times to try again. If you still can not connect to access point by this way, please make sure the PIN code you provided to access point is correct.

2-9 About

The About tab provides you the information about version numbers of configuration utility, firmware, and other important information about your wireless network card. Please follow the following instructions to see these information: 1. Right-click the Edimax configuration utility icon located at lower-right corner of computer desktop, then click Launch Config Utilities.
2. Click About tab, and the following settings will appear:
If you need assistance about network problem, youll need these values. You can also click www.edimax.com button to go to the web site of network card driver manufacturer and get more information about your wireless network card. Please click OK to close configuration utility.
CHAPTER III: Soft-AP Function
Excepting become a wireless client of other wireless access points, this wireless card can act as a wireless service provider also! You can switch this wireless cards operating mode to AP mode to simulate the function of a real wireless access point by software, and all other computers and wireless devices can connect to your computer wirelessly, even share the internet connection you have! Please follow the instructions in following chapters to use the AP function of your wireless card.
3-1 Switch to AP Mode and Basic Configuration
The operating mode of the wireless card is Station Mode (becoming a client of other wireless access points) by default. If you want to switch to AP mode, please right-click Edimax utility icon, and select Switch to AP Mode.

Beacon(ms)

Idle Time
No forwarding among wireless clients Hide SSID
Check this box and the SSID will not be broadcasted to the public. Your wireless clients must know the exact SSID to be able to connect to your computer. This option is useful to enhance security level. Check this box to allow BW 40MHz capability.

Allow BW 40 MHz Default

Click this button to restore all settings in this page back to default value.
Apply Click this button to activate current settings. To exit, click X button at the upper-right corner of configuration window.

3-2 Security Settings

This wireless card supports wireless encryption in AP mode, which will encrypt the data being transferred over the air to enhance data security level. Its recommended to enable data encryption unless you wish to open your computer (and its internet connection) to the public. When you click Security Setting in Edimax configuration utility, the following window will appear:
Here are descriptions of every setup items: Authentication Please select a wireless authentication type you Type wish to use. Available options are Open, Shared, WPA-PSK, WPA2-PSK, and WPA-PSK / WPA2-PSK. If you want to disable wireless data encryption, you must select Open or Shared.
Encryption available Type
Please select an encryption mode. The options in this setting item will vary depending on the authentication type you select. If you select Not Use, data will not be encrypted and people with some networking knowledge will be able to read the data you transfer with proper tool. NOTE: WPA encryption is safer than WEP, however, some older wireless clients dont support WPA encryption.

WPA Pre-shared Key

Please input the WPA pre-shared key here. Only clients with the same pre-shared key you inputted here will be able to connect to your computer. This setting is only available when you select one of WPA encryptions. You can specify the time interval to re-issue the key to your wireless clients here. You can click the button 10 seconds or Kpackets to change the unit of time interval. (every 10 seconds or a thousand data packets times the value you specified in Group Rekey Interval field) Please input the WEP encryption key here when you select WEP as encryption type. There are 2 types of WEP key: Hex (number 0 to 9, and ASCII characters A to F) and ASCII (all alphanumerical characters plus symbols). Please select the type of WEP key first, and then input the WEP key according to the type of WEP key you selected.

2. Click Event Log tab, and the event log will be displayed:
You can click Clear to remove all entries in the log.

3-6 Statistics

If you want to know detailed information about how your software access point works, you can follow the following instructions to view the statistics of the access point: 1. Right-Click Edimax configuration utility icon, and select Switch to AP Mode
2. Click Statistics tab, and the event log will be displayed:
You can click Reset Counter button to reset all counters to zero.

CHAPTER IV: APPENDIX

4-2 Troubleshooting
If you encounter any problem when youre using this wireless network card, dont panic! Before you call your dealer of purchase for help, please check this troubleshooting table, the solution of your problem could be very simple, and you can solve the problem by yourself! Scenario Solution I cant find any wireless 1. Click Rescan for few more times access point / wireless and see if you can find any wireless device in Site Survey access point or wireless device. function. 2. Please move closer to any known wireless access point. 3. Ad hoc function must be enabled for the wireless device you wish to establish a direct wireless link. 4. Please adjust the position of network card (you may have to move your computer if youre using a notebook computer) and click Rescan button for few more times. If you can find the wireless access point or wireless device you want to connect by doing this, try to move closer to the place where the wireless access point or wireless device is located. Nothing happens when 1. Please make sure the wireless I click Launch config network card is inserted into your utilities computers USB port. If the Edimax configuration utilitys icon is black, the network card is not detected by your computer.
I can not establish connection with a certain wireless access point
The network is slow / having problem when transferring large files
2. Reboot the computer and try again. 3. Remove the card and insert it into another USB port. 4. Remove the driver and re-install. 5. Contact the dealer of purchase for help. 1. Click Connect for few more times. 2. If the SSID of access point you wish to connect is hidden (nothing displayed in SSID field in Site Survey function), you have to input correct SSID of the access point you wish to connect. Please contact the owner of access point to ask for correct SSID. 3. You have to input correct passphrase / security key to connect an access point with encryption. Please contact the owner of access point to ask for correct passphrase / security key. 4. The access point you wish to connect only allows network cards with specific MAC address to establish connection. Please go to About tab and write the value of Phy_Addess down, then present this value to the owner of access point so he / she can add the MAC address of your network card to his / her access points list. 1. Move closer to the place where access point is located. 2. Enable Wireless Protection in Advanced tab. 3. Try a lower TX Rate in Advanced tab. 4. Disable Tx Burst in Advanced tab. 5. Enable WMM in QoS tab if you

11. Would the information be intercepted while transmitting on air? WLAN features two-fold protection in security. On the hardware side, as with Direct Sequence Spread Spectrum technology, it has the inherent security feature of scrambling. On the software side, WLAN series offer the encryption function (WEP) to enhance security and Access Control. Users can set it up depending upon their needs. 12. What is DSSS? What is FHSS? And what are their differences? Frequency-hopping spread-spectrum (FHSS) uses a narrowband carrier that changes frequency in a pattern that is known to both transmitter and receiver. Properly synchronized, the net effect is to maintain a single logical channel. To an unintended receiver, FHSS appears to be short-duration impulse noise. Direct-sequence spread-spectrum (DSSS) generates a redundant bit pattern for each bit to be transmitted. This bit pattern is called a chip (or chipping code). The longer the chip is, the greater the probability that the original data can be recovered. Even if one or more bits in the chip are damaged during transmission, statistical techniques embedded in the radio can recover the original data without-the need for retransmission. To an unintended receiver, DSSS appears as low power wideband noise and is rejected (ignored) by most narrowband receivers. 13. What is Spread Spectrum? Spread Spectrum technology is a wideband radio frequency technique developed by the military for use in reliable, secure, mission-critical communication systems. It is designed to trade off bandwidth efficiency for reliability, integrity, and security. In other words, more bandwidth is consumed than in the case of narrowband transmission, but the trade off produces a signal that is, in effect, louder and thus easier to detect, provided that the receiver knows the parameters of the spread-spectrum signal being broadcast. If a receiver is not tuned to the right frequency, a spread spectrum signal looks like background noise. There are two main alternatives, Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS). 14. What is WMM? Wi-Fi Multimedia (WMM), a group of features for wireless networks that improve the user experience for audio, video

and voice applications. WMM is based on a subset of the IEEE 802.11e WLAN QoS draft standard. WMM adds prioritized capabilities to Wi-Fi networks and optimizes their performance when multiple concurring applications, each with different latency and throughput requirements, compete for network resources. By using WMM, end-user satisfaction is maintained in a wider variety of environments and traffic conditions. WMM makes it possible for home network users and enterprise network managers to decide which data streams are most important and assign them a higher traffic priority.
15. What is WMM Power Save? WMM Power Save is a set of features for Wi-Fi networks that increase the efficiency and flexibility of data transmission in order to conserve power. WMM Power Save has been optimized for mobile devices running latency-sensitive applications such as voice, audio, or video, but can benefit any Wi-Fi device. WMM Power Save uses mechanisms included in the IEEE 802.11e standard and is an enhancement of IEEE 802.11 legacy power save. With WMM Power Save, the same amount of data can be transmitted in a shorter time while allowing the Wi-Fi device to remain longer in a low-power dozing state. 16. What is GI? GI stands for Guard Interval. Its a measure to protect wireless devices from cross- interference. If there are two wireless devices using the same or near channel, and they are close enough, radio interference will occur and reduce the radio resource usability. 17. What is STBC? STBC stands for Space-Time Block Coding, which is a technique used to transfer multiple copies of data by multiple antenna, to improve data transfer performance. By using multiple antennas, not only data transfer rate is improved, but also the wireless stability. 18. What is WPS? WPS stands for Wi-Fi Protected Setup. It provides a simple way to establish unencrypted or encrypted connections between wireless clients and access point automatically. User can press a software or hardware button to activate WPS function, and WPS-compatible wireless clients and access