 Introduction  Components of Wi-Fi and its working  IEEE Architecture  Advantages and Limitations

What Is WiFi? The Wi-Fi Alliance Interoperability Wi-Fi Technology

 The term Wi-Fi is often used as a synonym for wireless LAN(WLAN).  A wireless network uses radio waves, just like cell phones, televisions and radios do.radio wavescell phonestelevisions  Uses high frequency radio waves rather than wires to communicate between nodes.  Wi-Fi is a generic term that refers to the IEEE standard.

 A global association of companies, promotes WLAN technology and certifies products if they conform to certain standards of interoperability.  Not every IEEE compliant device is submitted for certification to the Wi-Fi Alliance, sometimes because of costs associated with the certification process.

 It means that products from different companies will work together, so users don't get locked into a single brand of Wi-Fi products.  Wi-Fi Alliance member companies can submit products for certification.  Wi-Fi CERTIFIED products will contain a logo identifying which features have been tested and that the product has met all the standards of the notation.

YearData TransferFrenqency IEEE Mbps2.4 GHz Unregulated IEEE b Mbps2.4 GHz Unregulated IEEE a Mbps5GHz Regulated IEEE g Mbps2.4 GHz

 Introduction  Components of Wi-Fi and its working  IEEE Architecture  Advantages and Limitations

Access Point Hot Spot Wi-Fi cards Safe guards

 The AP is a wireless LAN transceiver or “base station” that can connect one or many wireless devices simultaneously to the Internet. Access Point (AP)

 They accept the wireless signal. They can be internal and external.(e.g PCMCIA Card for Laptop and PCI Card for Desktop PC) Safeguards Firewalls and anti-virus software protect networks from uninvited users and keep information secure Wi-Fi cards

 A Wi-Fi hotspot is created by installing an access point to an internet connection.  When Wi-Fi enabled device encounters a hotspot the device can then connect to that network wirelessly.  A single access point can support up to 30 users and can function within a range of 100 up to 300 feet.

 It’s a two-way radio communication.  A computer's wireless adapter translates data into a radio signal and transmits it using an antenna.  A wireless router receives the signal and decodes it. The router sends the information to the Internet using a physical, wired Ethernet connection.routerEthernet  The process also works in reverse….

 Introduction  Components of Wi-Fi and its working  IEEE Architecture  Advantages and Limitations

BSS ESS Station Types

 IEEE defines three types of stations based on their mobility in a wireless LAN  No transition mobility-Station is stationary or move only inside a BSS  BSS transition mobility-Station can move from one BSS to another but confined inside one ESS  ESS transition mobility-station can move from one ESS to another. How ever there is no guarantee that the communication is continuous during the move.

 Introduction  Components of Wi-Fi and its working  IEEE Architecture  Advantages and Limitations

 Long-Term Cost Savings  Reduced Installation Time  Mobility  Scalability  Easy access to the Internet in public places

 Interference  Degradation in performance  High power consumption  Limited range

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