Wi-Fi Technology By Marc Bailey

What is Wi-Fi? Wi-Fi or Wireless Fidelity is a wireless technolgy owned by the Wi-Fi Alliance (formed in 1999) Goal: Improve the use and exchange of information on wireless local area network products Uses the Institute of Electrical and Electronics Engineers (IEEE) standards

Standards a - High frequency - More “flexible” and “reliable” - (Tomsho, Tittel, & Johnson) - Problematic with upgrades from the b standard b - Most common - Longest in use

Standards (cont.) g - High frequency - Backwards compatible with b

How does Wi-Fi Work? Rather than using wires to connect, Wi-Fi uses radio waves as the medium Extention to Ethernet Range is several feet to serveral hundred feet (depending on environment and interference) OSI Model: Physical Layer

Using Wi-Fi Devices: PCs, game consoles, cell phones, mp3 players, and PDAs Network Design: Hotspots and Mesh Networks Peer-to-peer: Consumer electronics and gaming Who uses it?: Consumers with Wi-Fi technology and businesses

Hotspots Localized wireless access areas Various locations: Train stations, airports, coffee shops, universities, etc. Commerical Hotspots - Portals for authentication and payment - Payment options (credit card, PayPal, etc.) - Smaller buisnesses may offer free service Examples: Hotels and small airports

Hotspots (cont.) Free Hotspots - Open public network with a Wi-Fi router - Can be a closed public network with the right software that protects and manages the network A security issue especially when dealing with an unsecured hotspot

Wi-Fi Pros No wires for machines Good for places that are difficult to get cables into Drops in price Interoperable: Works anywhere a Wi-Fi connection is available since Wi-Fi is a global set of standards

Wi-Fi Cons Wi-Fi channels used not the same worldwide High power consumption Limited range (but can be improved by antennas) Wi-Fi pollution: High number of access points in one area can lead to interference

Security Options Service Set Identifier (SSID) - Uniquely identifies the wireless LAN with a configured alphanumeric label. Wired Equivalency Protocol (WEP) - A widely available data encryption. It does have the chance of being cracked by a motivated attacker. Wi-Fi Protocol Access (WPA) - An upgrade over WEP in terms of security. The data encryption is harder to crack due to the key automatically changing periodically.

Security Options (cont.) i or WPA2 - Similar to WPA, but incorporates more advanced data encryption. Mac Address Filtering - Limits which computers can use the network based on their MAC addresses. Not practical for large networks.

Security: Hotspots Most are unsecured Even though it is costly, Virtual Private Networks (VPN) can be used Some companies provide downloadable WPA support Indentity theives and other criminals can set up a free public hotspot to steal valuable information. Commonly known as a “poisioned hotspot”

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References Guide to Networking Essentials - Fifth Edition by Greg Tomsho, Ed Tittel, & David Johnson