Wireless Networking Overview

Topics

Brief overview
Choosing a wireless local area network (LAN) mode
Configuring a wireless LAN
Identifying a wireless network
Surveying your wireless LAN site
Factors affecting range
Stronger security

Get software/drivers and technical support information for Intel wireless adapters

Brief overview

A broadband wireless router is designed for home and small-office users. This term can be used interchangeably with an access point (AP) for the purpose of this document.

A wireless network connects computers without using network cables. Computers use radio communications to send data between each other. You can communicate directly with other wireless computers, or connect to an existing network through a wireless AP. When you set up your wireless adapter, you select the operating mode for the kind of wireless network you want. You can use your Intel® PRO/Wireless adapter to connect to other similar wireless devices that comply with the 802.11 standard for wireless networking.

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Choosing a wireless local area network (LAN) mode
Wireless LANs can work with or without an AP, depending on the number of users in the network. Infrastructure mode uses APs to allow wireless computers to send and receive information. Wireless computers transmit to the AP: the AP receives the information and rebroadcasts it to other computers. The access point can also connect to a wired network or to the Internet. Multiple access points can work together to provide coverage over a wide area.

Peer-to-Peer mode, also called Ad Hoc mode, works without access points and allows wireless computers to send information directly to other wireless computers. You can use Peer-to-Peer mode to network computers in a home or small office or to set up a temporary wireless network for a meeting.

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Configuring a wireless LAN
There are three basic components that must be configured for a wireless LAN to operate properly:

• The network name or service set identifier (SSID) - Each wireless network uses a unique network name to identify the network. This name is called the service set identifier (SSID). When you set up your wireless adapter, you specify the SSID.
  • If you are connecting to an existing network, you must use the SSID for that network.
  • If you are setting up your own network make up your own SSID and use it on each computer. The SSID can be up to 32 characters long using a combination of letters and numbers.
• Profiles - When you set up your computer to access a wireless network, Intel® PROSet creates a profile for the wireless settings that you specify. To connect to an existing network, you can make a temporary connection, or create a profile for that network. After you create profiles, your computer automatically connects when you change locations.
• Cisco* Compatible Extensions - Enabling Cisco Compatible Extensions provides interoperability with features of a Cisco wireless LAN infrastructure such as CKIP and LEAP.
• Security - The 802.11 wireless networks use encryption to help protect your data. If you are connecting to an existing network, use the encryption key provided by the administrator of the wireless network. When setting up a wireless LAN, you can strongly increase the level of data protection and access control using one of these methods:
  • Wi-Fi Protected Access2 (WPA2) - is currently the highest level of security offered in Wi-Fi networks. Home and small-office users can implement a simplified version that requires a preshared key, commonly called WPA2-Personal or WPA2-PSK. WPA2 implements 802.1x and key-exchange to strengthen data encryption using the Advanced Encryption Standard (AES).
  • Wi-Fi Protected Access (WPA) - is a security enhancement that strongly increases the level of data protection and access control to a Wireless LAN. Home and small-office users can implement a simplified version by creating a preshared key, commonly called WPA-Personal or WPA-PSK. WPA enforces 802.1x authentication and key-exchange to strengthen data encryption using Temporal Key Integrity Protocol (TKIP).

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Identifying a wireless network
Depending on the size and components of a wireless LAN, there are many ways to identify a wireless LAN:

• The network name or service set identifier (SSID) - Identifies a wireless network. All wireless devices on the network must use the same SSID.
• Extended Service Set Identifier (ESSID) - A special case of SSID used to identify a wireless network that includes access points.
• Independent Basic Service Set Identifier (IBSSID) - A special case of SSID used to identify a network of wireless computers configured to communicate directly with one another without using an access point.
• Basic Service Set Identifier (BSSID) - A unique identifier for each wireless device. The BSSID is the Ethernet MAC address of the device.
• Broadcast SSID - An access point can respond to computers sending probe packets with the broadcast SSID. If this feature is enabled on the access point, any wireless user can associate with the access point by using a blank (null) SSID.

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Surveying your wireless LAN site
Conducting a site survey for your wireless LAN is the most crucial step of setting up a wireless network. A site survey will greatly reduce the amount of troubleshooting for connection testing. To conduct a site survey, you need the following tools:

• An access point (AP), or laptop computer that is set up to be the transmitter. It should be mounted near and at the same height as the designated location of your wireless LAN.
• A laptop loaded with your site survey, to act as the mobile receiver.
• An area or building map, to plot the strength of your signals.

Once you have the tools you need, launch the site survey software on the mobile receiver.

• Carry the mobile receiver around the intended wireless LAN area to test the signal strength.
• Check the signal strength of each intended AP location. If you encounter a problem with a location, make sure it is not located on a wall containing metal, such as an air conditioning duct. Flooring constructed of metal can also impact range in multi-floor buildings.
• For seamless coverage within your LAN, the signal levels at each point must overlap. Software available that can seamlessly pass changing signal levels from one AP to another.

When signal strength is strong inside the building, check the strength outside the building. Carry the mobile receiver as far down the street or around the building as you can, without losing significant signal strength.

To improve wireless security, be aware of the types of networks used by the companies around you. This knowledge will help you select the right channels and best location for your APs.

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Factors affecting range
An access point (AP) can transmit a signal up to 60 feet in areas with many walled barriers or as much as 500 feet in large open areas. Range is affected by the following factors:

• Building materials, such as steel and drywall, can shorten the range of the radio signals.
• Physical layout of the area can interfere and cause dropped signals.
• Electronic noise from cell phones, microwave ovens, or other devices on the same frequency, can interfere with signal transmissions.
• Data rate, impacts signal distance. The faster signals are sent, the less distance they travel.

Taking these factors into consideration when you survey the site for your WLAN is key to providing users with undisturbed mobile connectivity. Using multiple APs can reduce the impact of these factors if your area has dividing walls throughout.

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Stronger security
Your network is still vulnerable, even after you enable the security settings defined in the 802.11b standard, and the security settings of your hardware. Here are a few things you can do to improve security, making it harder for outsiders to access your network:

• Change the default network name of your WLAN. Every manufacturer's default settings are public knowledge.
• Enable encryption. TKIP encryption provides greater protection than WEP.
• Change your encryption keys as often as possible. Change the key (or pass phrase) for Wi-Fi Protected Access (WPA) preshared key (PSK) mode.
• Enable MAC address filtering so that each access point (AP) can generate a list of approved MAC addresses for your WLAN.
• If you have a small network, use virtual private network encryption.
• If you have a large network, you can install a gateway between your APs and network clients.
• Intel® wireless adapters and Intel® PROSet Software v7.1.4 and later versions support the latest security standards, including WPA and WPA2, to address the security concerns of the original 802.11 implementations. Download the latest recommended Intel® Software and Drivers for your Intel® wireless adapter.
• Intel® Centrino® Mobile Technology users with Intel® PRO/Wireless 2100 Network Connection are recommended to upgrade systems to the latest software.

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