LINKSYS WPCI54G Users Manual

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Wireless-G Notebook Adapter

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The Profiles screen (Figure 7-6) lets you save different configuration profiles for different network setups. You can also import or export profiles. The default profile holds the initial conf iguration saved when you ran the Setup Wizard.

Profile - Name of the connection profile. SSID - The wireless network’s unique name, as set in the connection profile.

Profile Information Network Type - The mode of the wireless network currently in use. Transfer Rate - The data transfer rate of the current connection. (In Auto

mode, the Adapter dynamically shifts to the fastest data transfer rate possible at any given time.)

Channel - The channel to which the wireless network devices are set. WEP - The status of the WEP encryption security feature.

Connect - To connect to a wireless network using a specific prof ile, select the profile, and click the Connect button.

Edit - Select a profile, and click the Edit button to change an existing prof ile.

New - Click the New button to create a new profile. See the next section,

“Creating a New Profile,” for detailed instructions.

Figure 7-6

Profiles

Site Information Wireless Mode - The mode of the wireless network currently in use. Channel - The channel to which the wireless network devices are set. WEP - The status of the WEP encryption security feature. MAC - The MAC address of the wireless network’s access point. Surveyed at - The time at which the wireless network was scanned.

Refresh - Click the Refresh button to perform a new search for wireless

devices.

Connect - To connect to one of the networks on the list, select the wireless network, and click the Connect button. If the wireless network has WEP encryption enabled, you will see the screen shown in Figure 7-5.

In the WEP drop-down box, select the type of WEP encryption used by the wireless network: 64-bit, or 128-bit WEP.

If the wireless network uses a passphrase, enter the passphrase in the Passphrase f ield. If the wireless network uses a WEP key, enter the WEP key in the Key 1 field.

Click the OK button to complete the network connection and return to the Site Survey screen, or click the Cancel button to cancel the network connection and return to the Site Survey screen.

On the Site Survey screen, click the X (Close) button in the upper right corner to exit the WLAN Monitor.

Figure 7-5

Wireless-G Notebook Adapter

1. On the Profiles screen, shown in Figure 7-6, click the New button to create a new profile.

2. When the Create connection profile screen appears (Figure 7-9), enter a name for the new profile. Click OK to save the profile name or click Cancel to return to the previous screen.

3. The Choose a network type screen (Figure 7-10) shows a choice of two wireless modes. Click the Infrastructure Mode radio button if you want your wireless computers to communicate with computers on your wired network via a wireless access point. Click the Ad-Hoc Mode radio button if you want multiple wireless computers to communicate directly with each other. Click the Next button to continue or the Back button to return to the previous screen.

Infrastructure Mode - This mode allows wireless and wired networks to communicate through an access point.

Ad-Hoc Mode - This mode allows wireless-equipped computers to communicate directly with each other. No access point is used.

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Figure 7-10

Figure 7-9

Creating a New Profile

Import - Click the Import button to import a profile that has been saved in another location. From the screen that appears (shown in Figure 7-7), select the appropriate file, and click the

Open button.

Export - To save the profile(s) in

a different location, click the Export button. On the screen that appears (Figure 7-8), direct Windows to the appropriate folder and click the OK button.

Delete - Click the Delete button to delete a prof ile.

Click the X (Close) button in the upper right corner to exit the WLAN Monitor.

Figure 7-7

Figure 7-8

Note: If you have more than one profile, all profiles will be automatically selected and exported to the same folder.

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4. The Wireless Settings screen (Figure 7-11) will appear. If you chose Infrastructure Mode, go to Step 5 now. If you chose Ad-Hoc Mode, select the correct operating channel for your network from the Channel drop- down menu. Then, select the Network Mode from the drop-down menu. Click the Next button, and go to Step 5. Click the Back button to change any settings.

Channel - The channel you choose should match the channel set on the other devices in your wireless network. If you are unsure about which channel to use, select the default channel (Channel 6).

Network Mode - Select Mixed Mode, and both Wireless-G and Wireless- B computers will be allowed on the network, but the speed will be reduced. Select G-Only Mode for maximum speed, but no Wireless-B users will be allowed on the network.

5. The Network Setting screen (Figure 7-12) will appear.

If your network has a DHCP server, click the radio button next to Obtain an IP address automatically (DHCP). Click the Next button to continue, or click the Back button to return to the previous screen.

If your network does not have a DHCP server, click the radio button next to

Specify the IP address. Enter an IP Address, Subnet Mask, Default Gateway, and DNS appropriate for your network. Enter each address in this

format: xxx.xxx.xxx.xxx (the x’s represent the numbers that make up each address). You must specify the IP Address and Subnet Mask on this screen. If you are unsure about the Default Gateway and DNS addresses, then leave these fields alone.

IP Address - This IP Address must be unique to your network.

Subnet Mask - The Adapter’s Subnet Mask must be the same as your wired

network’s Subnet Mask.

Default Gateway - Enter the IP address of your network’s Gateway here.

DNS - Enter the DNS addresses of your Ethernet (wired) network here.

Click the Next button to continue or the Back button to return to the previous screen.

6. The Security Settings screen (Figure 7-13) will appear. Enable or disable Wired Equivalent Privacy (WEP) encryption for your wireless network. If you enable WEP, enter a Passphrase or WEP key. Click the Next button to continue or the Back button to return to the previous screen.

Figure 7-12

Figure 7-11

Wireless-G Notebook Adapter

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WEP (Disabled/64 bits WEP/128 bits WEP) - If you do not want to use WEP encryption, choose Disabled. To use WEP encryption (recommended to increase network security), select 64 bits or 128 bits WEP from the drop-down menu, and enter either a Passphrase or WEP key.

Passphrase - Instead of manually entering WEP keys, you can enter a Passphrase, so that a WEP key is automatically generated. It is case-sensitive and should not be longer than 16 alphanumeric characters. This passphrase must match the passphrase of your wireless network and is compatible with other Linksys wireless products only. (If you have any nonLinksys wireless products, enter the WEP key(s) manually on those products.)

Key 1 - This WEP key must match the WEP key of your wireless network. If you are using 64-bit WEP encryption, then the key must consist of exactly 10 hexadecimal characters. If you are using 128-bit WEP encryption, then the key must consist of exactly 26 hexadecimal characters. Valid hexadecimal characters are “0” to “9” and “A” to “F”.

7. The Conf irm New Settings screen

(Figure 7-14) will appear. To save the new settings, click the Ye s button. To cancel the settings and return to the Profiles screen, click the No button. To edit the new settings, click the Back button.

8. The Congratulations screen (Figure 7-15) will appear next. Click Activate new settings now to implement the new settings immediately and return to the Link Information screen. Click Activate new settings later to keep the current settings active, and return to the Profiles screen so that you can edit your profile or create another profile.

You have successfully created a connection profile. Click the X (Close) but-

ton in the upper right corner to exit the WLAN Monitor.

Figure 7-14

Figure 7-15

Figure 7-13

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Can I play computer games with other members of the wireless network?

Yes, as long as the game supports multiple players over a LAN (local area network). Refer to the game’s user guide for more information.

What is the IEEE 802.11b standard?

It is one of the IEEE standards for wireless networks. The 802.11b standard allows wireless networking hardware from different manufacturers to communicate, provided that the hardware complies with the 802.11b standard. The

802.11b standard states a maximum data transfer rate of 11Mbps and an oper-

ating frequency of 2.4GHz.

What IEEE 802.11b features are supported?

The product supports the following IEEE 802.11b functions:

• CSMA/CA plus Acknowledge protocol

• Multi-Channel Roaming

• Automatic Rate Selection

• RTS/CTS feature

• Fragmentation

• Power Management

What is ad-hoc mode?

When a wireless network is set to ad-hoc mode, the wireless-equipped computers are configured to communicate directly with each other. The ad-hoc wireless network will not communicate with any wired network.

What is infrastructure mode?

When a wireless network is set to infrastructure mode, the wireless network is configured to communicate with a wired network through a wireless access point.

What is roaming?

Roaming is the ability of a portable computer user to communicate continuously while moving freely throughout an area greater than that covered by a single access point. Before using the roaming function, the workstation must make sure that it is the same channel number with the access point of dedicated coverage area.

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Appendix A: Troubleshooting

This chapter provides solutions to problems that may occur during the installation and operation of the Wireless-G PCI Adapter. Read the descriptions below to solve your problems. If you can’t find an answer here, check the Linksys website at www.linksys.com.

1. The Wireless-G PCI Adapter does not work properly.

• Reinser t the Wireless-G PCI Adapter into your PC’s PCI slot.

• Right click on My Computer and select Properties. Select the device manager and click on the Network Adapter. You will find the Wireless-G PCI Adapter if it is installed successfully. If you see the yellow exclamation mark, the resources are conflicting. You will see the status of the Wireless-G PCI Adapter. If there is a yellow question mark, please check the following:

• Make sure that your PC has a free IRQ (Interr upt ReQuest, a hardware

interrupt on a PC.)

• Make sure that you have inserted the right adapter and installed the proper driver.

If the Wireless-G PCI Adapter does not function after attempting the above

steps, remove the adapter and do the following:

• Uninstall the driver software from your PC.

• Restar t your PC and repeat the hardware and software installation as specified in this User Guide.

2. I cannot communicate with the other computers linked via Ethernet in the Infrastructure configuration.

• Make sure that the PC to which the Wireless-G PCI Adapter is associated

is powered on.

• Make sure that your Wireless-G PCI Adapter is conf igured on the same

channel and with the same security options as with the other computers in the Infrastructure configuration.

Can I run an application from a remote computer over the wireless network?

This will depend on whether or not the application is designed to be used over a network. Consult the application’s user guide to determine if it supports operation over a network.

Common Problems and Solutions

Frequently Asked Questions

Wireless-G Notebook Adapter

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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, 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.

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 offers the encryption function (WEP) to enhance security and access control.

What is WEP?

WEP is Wired Equivalent Privacy, a data privacy mechanism based on a 64-bit or 128-bit shared key algorithm, as described in the IEEE 802.11 standard.

To achieve true seamless connectivity, the wireless LAN must incorporate a number of different functions. Each node and access point, for example, must always acknowledge receipt of each message. Each node must maintain contact with the wireless network even when not actually transmitting data. Achieving these functions simultaneously requires a dynamic RF networking technology that links access points and nodes. In such a system, the user’s end node undertakes a search for the best possible access to the system. First, it evaluates such factors as signal strength and quality, as well as the message load currently being carried by each access point and the distance of each access point to the wired backbone. Based on that information, the node next selects the right access point and registers its address. Communications between end node and host computer can then be transmitted up and down the backbone.

As the user moves on, the end node’s RF transmitter regularly checks the system to determine whether it is in touch with the original access point or whether it should seek a new one. When a node no longer receives acknowledgment from its original access point, it undertakes a new search. Upon finding a new access point, it then re-registers, and the communication process continues.

What is ISM band?

The FCC and their counterparts outside of the U.S. have set aside bandwidth for unlicensed use in the ISM (Industrial, Scientific and Medical) band. Spectrum in the vicinity of 2.4 GHz, in particular, is being made available worldwide. This presents a truly revolutionary opportunity to place convenient high-speed wireless capabilities in the hands of users around the globe.

What is Spread Spectrum?

Spread Spectrum technology is a wideband radio frequency technique developed by the military for use in reliable, secure, mission-critical communications 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).

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

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CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) - In local area networking, this is the CSMA technique that combines slotted time-division multiplexing with carrier sense multiple access/collision detection (CSMA/CD) to avoid having collisions occur a second time. This works best if the time allocated is short compared to packet length and if the number of situations is small.

CTS (Clear To Send) - An RS-232 signal sent from the receiving station to the transmitting station that indicates it is ready to accept data.

Default Gateway - The routing device used to forward all traffic that is not addressed to a station within the local subnet.

DHCP (Dynamic Host Conf iguration Protocol) - A protocol that lets network administrators manage centrally and automate the assignment of Internet Protocol (IP) addresses in an organization's network. Using the Internet's set of protocol (TCP/IP), each machine that can connect to the Internet needs a unique IP address. When an organization sets up its computer users with a connection to the Internet, an IP address must be assigned to each machine. Without DHCP, the IP address must be entered manually at each computer and, if computers move to another location in another part of the network, a new IP address must be entered. DHCP lets a network administrator supervise and distribute IP addresses from a central point and automatically sends a new IP address when a computer is plugged into a different place in the network.

DHCP uses the concept of a "lease" or amount of time that a given IP address will be valid for a computer. The lease time can vary depending on how long a user is likely to require the Internet connection at a particular location. It's especially useful in education and other environments where users change frequently. Using very short leases, DHCP can dynamically reconfigure networks in which there are more computers than there are available IP addresses.

DHCP supports static addresses for computers containing Web servers that need a permanent IP address.

DNS - The domain name system (DNS) is the way that Internet domain name are located and translated into Internet Protocol (IP) addresses. A domain name is a meaningful and easy-to-remember "handle" for an Internet address.

Domain - A subnetwork comprised of a group of clients and servers under the control of one security database. Dividing LANs into domains improves performance and security.

Appendix B: Glossary

802.11b - One of the IEEE standards for wireless networking hardware.

Products that adhere to a specific IEEE standard will work with each other, even if they are manufactured by different companies. The 802.11b standard specifies a maximum data transfer rate of 11Mbps, an operating frequency of

2.4GHz, and WEP encryption for security. 802.11b networks are also referred

to as Wi-Fi networks.

802.11g - A proposed, but as yet unratified extension of the IEEE 802.11 stan-

dard for wireless networking hardware. The draft 802.11g specifications used by Linksys specify a maximum data transfer rate of 54Mbps using OFDM modulation, an operating frequency of 2.4GHz, backward compatibility with IEEE 802.11b devices, and WEP encryption for security.

Adapter - Printed circuit board that plugs into a PC to add to capabilities or connectivity to a PC. In a networked environment, a network interface card is the typical adapter that allows the PC or server to connect to the intranet and/or Internet.

Ad-hoc Network - An ad-hoc network is a group of computers, each with a wireless adapter, connected as an independent 802.11 wireless LAN. Ad-hoc wireless computers operate on a peer-to-peer basis, communicating directly with each other without the use of an access point. Ad-hoc mode is also referred to as an Independent Basic Service Set (IBSS) or as peer-to-peer mode, and is useful at a departmental scale or SOHO operation.

Backbone - The part of a network that connects most of the systems and networks together and handles the most data.

Bandwidth - The transmission capacity of a given facility, in terms of how much data the facility can transmit in a fixed amount of time; expressed in bits per second (bps).

Bit - A binary digit. The value - 0 or 1-used in the binary numbering system. Also, the smallest form of data.

BSS (Basic Service Set) - An infrastructure network connecting wireless devices to a wired network using a single access point.