Basics of Wi-Fi Technology

Basics of Wi-Fi Technology

Introduction:

Wireless technology is an alternative to WIRED TECHNOLOGY, which is commonly used, for connecting devices in wireless mode.

Wi-Fi (Wireless Fidelity) is a generic term that refers to the IEEE 802.11 communications standard for Wireless Local Area Networks (WLANs). Wi-Fi Network connect computers to each other, to the internet and to the wired network.

History:

The term "Wi-Fi" stands for "Wireless Fidelity“. Wi-Fi" was coined by a brand consulting firm called interband Corporation. Wi-Fi was invented in 1991 by NCR corporation /AT&T/AT&T in Nieuwegein , the Netherlands. The first wireless product was brought on the market under the name WaveLAN with speeds of 1Mbit/s to 20Mbit/s.

The Wi-Fi Technology:

Wi-Fi Networks use Radio Technologies to transmit & receive data at high speed:

• IEEE 802.11b

• IEEE 802.11a

• IEEE 802.11g

Purpose:

The main aims of Wi-Fi are the following:

• make access to information easier.
• ensure compatibility and co-existence of devices.
• eliminate cabling and wiring.
• eliminate switches, adapters, plugs, pins and connectors.

Elements of a WI-FI Network

• Access Point (AP)
• Wi-Fi cards
• Safeguards

Hotspot:

• A hotspot is a venue that offers Wi-Fi access to the Internet.
• Commercial Hotspots
• Billing
• Free Wi-Fi hotspots
• Security Concerns

Building a wireless Network:

• create a wireless network with a wireless access point
• Wireless router is used to connect the computers to one another,to a printer and to the internet.
• Most routers let you use a Web interface to change your settings. One can select: (1.)The name of the network, i.e; service set identifier. (2.)The channel that the router uses. (3.)Your router's security options.
• To keep your network private, you can use one of the following methods: (a.) WiFi Protected Access (WPA) (b.) Media Access Control (MAC)

How a Wi-Fi Network Works:

• Basic concept is same as Walkie talkies.
• A Wi-Fi hotspot is created by installing an access point to an internet connection.
• An access point acts as a base station.
• 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 – 150 feet indoors and up to 300 feet outdoors.
• Many access points can be connected to each other via Ethernet cables to create a single large network.

Wi-Fi Network Topologies:

1. AP-based topology (Infrastructure Mode)
2. Peer-to-peer topology (Ad-hoc Mode)
3. Point-to-multipoint bridge topology

Examples:

• AP-based topology (Infrastructure Mode)

• Peer-to-peer topology (Ad-hoc Mode)

• Point-to-multipoint bridge topology

Wi-Fi Applications:

1. Home
2. Small Businesses or SOHO
3. Large Corporations & Campuses
4. Health Care
5. Wireless ISP (WISP)
6. Travellers

Wi-Fi Security Threats:

1. Wireless technology doesn’t remove any old security issues, but introduces new ones
2. Eavesdropping
3. Man-in-the-middle attacks
4. Denial of Service

Wi-Fi Security:

The requirements for Wi-Fi network security can be broken down into two primary components:

1. Authentication

• User Authentication
• Server Authentication

2. Privacy

Wi-Fi Security Techniques:

• Service Set Identifier (SSID)
• Wired Equivalent Privacy (WEP)
• 802.1X Access Control
• Wireless Protected Access (WPA)
• IEEE 802.11i

Uses:

• A Wi-Fi enabled device such as a PC, game console,mobile phone, MP3 player or PDA can connect to the Internet when within range of a wireless network connected to the Internet.
• Wi-Fi can make access publicly available at Wi-Fi hotspots provided either free of charge or to subscribers to various providers.
• Increasing the number of Wi-Fi access-points provides redundancy, support for fast roaming and increased overall network-capacity by using more channels or by defining smaller cells.

Advantages:

• Mobility
• Ease of Installation
• Flexibility
• Cost
• Reliability
• Security
• Use unlicensed part of the radio spectrum
• Roaming
• Speed

Limitations:

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