Wi-Fi technology

Wi-Fi technology : 

Wi-Fi technology Presented by Sindhu.S (Department of MCA)

What is wi-fi : 

What is wi-fi Short for wireless fidelity and is mean to be used generically when referring to any type of network, whether 802.11b,802.11a,802.11g, dual brand ,etc.. Wi-fi is a wireless technology that uses radio frequency to transmit data through the air.

History of wi-fi : 

History of wi-fi IEEE (Institute of Electrical and Electronics Engineers) established the 802.11 Group in 1990. Specifications for standard ratified in 1997. Initial speeds were 1 and 2 Mbps IEEE modified the standard in 1999 to include 802.11 a and b 802.11g was added in 2003 802.11b equipment first available, then a, followed by g IEEE create standard but Wireless Ethernet Compatibility Alliance certifies product

What can you do with it? : 

What can you do with it? Quick/easy temp network access Staff access to Corporate network Patron(client ) internet access (hotspot) Interconnecting two networks

WI-FI LOGO : 

WI-FI LOGO

802.11b : 

802.11b Been around the longest, well-supported, stable, and cost effective, but runs in the 2.4 GHz range that makes it prone to interference from other devices (microwave ovens, cordless phones, etc) and also has security disadvantages Limits to the number of access points in range of each other, three Has 11 channels, with 3 non-overlapping, and supports rates from 1 to 11 Mbps, but realistically about 4-5 Mbps max Uses direct-sequence spread-spectrum technology

802.11g : 

802.11g Extension of 802.11b, with the same disadvantages (security and interference) Has a shorter range than 802.11b Is backwards compatible with 802.11b so it allows or a smooth transition from 11b to 11g Flexible because multiple channels can be combined for faster throughput, but limited to one access point Runs at 54 Mbps, but realistically about 20-25 Mbps and about 14 Mbps when b associated Uses frequency division multiplexing technology

802.11a : 

802.11a Completely different from 11b and 11g. Flexible because multiple channels can be combined for faster throughput and more access points can be colocated Shorter range than 11b and 11g Runs in the 5 GHz range, so less interference from other devices Has 12 channels, 8 non-overlapping, and supports rates from 6 to 54 Mbps, but realistically about 27 Mbps max Uses frequency division multiplexing technology

What do you need to do Wi-fi? : 

What do you need to do Wi-fi? Existing wired network/services (Infrastructure Mode) DHCP/DNS Access point Antennas and bridges Wireless adapter

Why Wi-Fi? : 

Why Wi-Fi? Setup Cost – Reduced cabling required Flexibility – Quick and easy to setup in temp or permanent space Scaleable – Can be expanded with growth Freedom – You can work from any location that you can get a signal Lower total cost of ownership – Because of affordability and low install cost Additionally Mobile Users – Can access the Corporate network from any public hotspot using VPN

Disadvantages : 

Disadvantages Planning – Depending on the goal Security – Greater exposure to risks Access Compromising Data Denial of Service Speed – Slower than cable Range – Affected by various medium Travels best through open space Reduced by walls, glass, water, etc

Security : 

Security Data Security/Encryption Third Party solution - Fortress Wi-Fi Protected Access (WPA) Wired Equivalent Privacy (WEP)-Shared key Access WPA/WEP Close System – No advertising MAC Authentication – MAC address control Attack – Denial of Service Client Protection Antivirus/Firewall

Range and Performance : 

Range and Performance Performance decreases as distance increases 802.11a Indoor 40-300 feet Outdoor – 100 to 1000 feet 802.11b Indoor 100-300 feet Outdoor 400 – 1500 feet Interference - doors, walls, furniture, ceiling 253 maximum number of client per AP, but 15-20 recommended

Infrastructure/Design : 

Infrastructure/Design Option 1 – Provide patron access using a totally separate network Infrastructure Option 2 – Use the existing corporate network, with additional equipment to provide access to patrons while securing internal network Option 3 – Use the existing corporate network, with same equipment to provide access to patrons while securing internal network

Separate Network-Option 1 : 

Separate Network-Option 1 Provide patron access using a separate network from your corporate network Advantages: Total internal network security, “a simple solution”, can provide redundancy for the existing internal network (however cost and complexity would increase) Disadvantages: More administrative overhead, more expensive (recurringservice charges)

Separate Network : 

Separate Network

Existing Network-Different Equipment- Option 2 : 

Existing Network-Different Equipment- Option 2 Use most of the existing infrastructure to provide access to patrons while securing internal network Advantages: Easier administration, Less expensive (No recurring monthly service charges), but cost for more hardware Disadvantages: Internal network down means no wireless access, “a more complex solution” (bandwidth, security,configuration implications)

Existing Network-Option 2 : 

Existing Network-Option 2

Existing Network-Same Equipment-Option 3 : 

Existing Network-Same Equipment-Option 3 Use the existing infrastructure to provide access to patrons while securing internal network Advantages: Easier administration, Least expensive (No recurring monthly service charges and no hardware) Disadvantages: Internal network down means no wireless access, most complex solution (bandwidth, security, configuration implications), using VLAN

Existing Network-Option 3 : 

Existing Network-Option 3

Services : 

Services Do you provide printing capability? Do you provide filtering for younger kids? Do you provide assistance with connectivity? Do you provide laptops for checkout? Do you provide PDA Support? Others Do you limit access to valid patrons only? Do you charge patrons for access?

Other Technical Services : 

Other Technical Services Required Services DHCP – Automatic IP assignment DNS – Website resolution Access Point Features HRP – Home Page Redirection Bandwidth Management SNMP Management Authentication – Free access for everyone? Accounting – Do you charge?

Cost : 

Cost Access Point - $20 to $1000 Extended Range Antenna-$20 to $100 802.11a/b/g Kit - $40 to $100 Active Ethernet - $100-$200 Wireless Adapter - $20 to 100 The average cost of adding a wired connection is about $400, more if conduit is needed.

Vendors : 

Vendors Netgear D-Link Linksys Proxim Cisco Enterasys Avaya Aruba Networks

Difference between bluetooth & wi-fi : 

Difference between bluetooth & wi-fi Bluetooth Technology: Different kinds of electronic equipement to communicate with each other.(ex: cell phone to wireless headset). Main: communicate one-on-one with each other. Wi-fi computers to communicate with each other, or with the Internet. communicate with any other device through a wireless router.

Slide 26: 

Blue tooth Usage Used for transmitting audio, such as from your cell phone to your wireless earpiece. Range It Covers short distance 10 feet is relatively straightforwardd Wi-fi Used for transmitting Internet signals from your cable or DSL modem to and from your computer. It covers larger distance 100 feet connection may be more difficult to establish.

Slide 27: 

bluetooth Connection and Installation Do not need any installation or configuration. Very simple & easy to access. Used for the formation of a wireless LAN(local area network). Wi-fi It requires some configuration. need to install router and modems. Allows usto form a PAN (Personal Area Network).

Slide 28: 

Bluetooth Transfer data at the rate of 800 kbps, Data Access: Cannot access database & software. Invention: Bluetooth 1.0 on 1998 Wi-fi Transfer data at the rate of 500 kbps. Can access database and softwares Wi-fi on 1990

Thanks & Regards SINDHU.S : 

Thanks & Regards SINDHU.S