WIRELESS LOCAL AREA NETWORK & WI-FI

WIRELESS LOCAL AREA NETWORK & WI-FIRona Mae BabaranMarianne BalceJasmine LalantoCelestian PepitoHajjelle RilleraWhat is a WLAN?Wireless Local Area NetworkGroup of computers that are connected using a wireless distribution method within a limited areaWhat are the advantanges to LAN?Increased ProductivityFast and Simple Network Set UpInstallation FlexibilityReduced Cost-of-OwnershipScalabilityWhat is 802.11Wireless networking hardware requires the use of underlying technology that deals with radio frequencies as well as data transmission. The most widely used standard is 802.11 produced by the Institute of Electrical and Electronic Engineers (IEEE). This is a standard defining all aspects of Radio Frequency Wireless networking.ArchitectureStationBSSIBSSInfrastracture BSSESSDistribution SystemBSSThe Basic Service Set (BSS) is a set of all stations that can communicate with each other. There are two types of BSS: Independent BSS and Infrastructure BSS. Every BSS has an id called the BSSID, it is the MAC address of the access point servicing the BSS.

IBSSIndependent Basic Service Set An Independent Basic Service Set or ad hoc network is the simplest of all IEEE 802.11 networks in that no network infrastructure is required. As such, an IBSS is simply comprised of one or more Stations which communicate directly with each other.Infrastracture BSSAn Infrastructure BSS can communicate with other stations not in the same basic service set by communicating to each other through Access Points.

ESSAn extended service set (ESS) is made up of two or more BSSs with APs. In this case, the BSSs are connected through a distribution system, which is usually a wired LAN.

SSIDa series of 0 to 32 octets. It is used as a unique identifier for a wireless LANDistribution SystemA distribution system connects Access Points in an extended service set. A distribution system is usually a wired LAN but can be a wireless LANOther Types of WLANBLUETOOTHHIPERLANTypes of Wireless Local Area NetworkTypes of WLANPrivate Wireless LANsUsually up to 200-ft radius.Suitable for homes and small businesses.Wide Area WLANUp to 10-mile radius.Same with Private WLAN but with more powerful antennas and transceivers.Used over a large industrial estate or parks.Types of WLANBusiness WLANExpansion of the Private WLAN.Use of multiple Access Points.Usually used in hotels and office buildings.Enterprise WLANExpansion of the Business WLAN.Usually found within governmental, academic, or large corporate organizations

Wireless LAN Basic modes of OperationWLAN Basic Modes of OperationInfrastructureMost Wi-Fi networks are deployed in this mode.A base stations acts as a wireless access point hub.Wireless access points are usually fixed.Can have multiple access points with the same SSID.

Infrastructure

WLAN Basic Modes of OperationPeer-to-Peer (Ad-Hoc)A network where stations communicate only peer to peer (P2P).It is done using the Independent Basic Service Set (IBSS)It allows wireless devices to directly communicate with each other. Easier to set-up if you just want to connect two devices to each other.

Peer-to-Peer

Wi-fiIntroductionWireless 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 802.11 standard for Wireless Local Area NetworksWi-Fi Network connect computers to each other, to the internet, and to the wired network.IntroductionIt usually operates using 2.4GHz(UHF) and 5GHz(SHF)Uses radio waves to provide wireless high-speedinternet andnetwork connections

Father of Wi-Fi

Vic HayesHistory1997Wi-Fi was first released for consumers802.11 standard was created1999Release of routers2003802.11g standard was created

History2009Arrival of 802.11n2012801.11ac was createdIEEE Standards IEEE standard 802.11a:first variety of IEEE 802.11 introduced in 2001operated in 5GHz ISM band Theindustrial, scientific and medical (ISM) radio bandsareradio bandsreserved internationally for the use ofradio frequency(RF) energy for industrial, scientific and medical purposes other than telecommunications.

-Theoretical speed: 54Mbps-Actual Speed: 15-20Mbps-Longest range: 50-75 ft

*less able to penetrate physical barriers like walls of the buildings* The modulation used is Orthogonal Frequency Division Multiplexing to enable to transfer at a maximum rate though the realistic is around 20Mbps

*The use of OFDM provides a significant reduction in the problems of interference caused by multipath effects. The use of OFDM also ensures that there is efficient use of the radio spectrum.*OFDM works by splitting the radio signal into multiple smaller sub-signals that are then transmitted simultaneously at different frequencies to the receiver. OFDM reduces the amount ofcrosstalkin signal transmissions. IEEE standard 802.11b: - wireless LAN standard to be widely adopted appear in late 1999-high rate or wifi* built in to many laptop computers and other forms of equipment- operates in 2.4GHz

* Devices operating in the 2.4GHz range include microwave ovens, Bluetooth devices, baby monitors, cordless telephones, and some amateur radio equipment.*interferences from mobile phones and Bluetooth devices can reduce the transmission speed

-Theoretical Speed: 11Mbps -Actual Speed: 4-6Mbps-Longest range: 70-150 ft

*better in penetrating physical barriers but more susceptible to interference*When transmitting data 802.11b uses the CSMA/CA (Carrier Sense Multiple Access)/ Collision Detection technique. If no transmission is taking place at the time, the particular station can transmit. If two stations attempt to transmit simultaneously, this causes a collision, which is detected by all participating stations. After a random time interval, the stations that collided attempt to transmit again. If another collision occurs, the time intervals from which the random waiting time is selected are increased.

IEEE standard 802.11g: -combination feature of IEEE 802.11a and IEEE 802.11b introduced in 2003* 802.11g attempts to combine the best of both 802.11a and 802.11b.-operates in 2.4GHz-supports a bandwidth up to 54Mbps-Longest range: 65-120ft - 802.11g is backwards compatible with 802.11b* 802.11g access points will work with 802.11b wireless network adapters and vice versa* Backward compatible(or sometimesbackward-compatibleor backwards compatible) refers to a hardware or software system that can successfully use interfaces and data from earlier versions of the system or with other systems.*has fast maximum speed *expensive devices*signal range is not easily blocked802.11nWireless network bearer operating in the 2.4 and 5 GHz ISM bandsMost widely available among the standardsBackward compatible with 802.11a, 802.11b, and 802.11gCan achieve speed as high as 140 megabits per second It was built with more antennas and multiple streams of dataIt can transmit up to 4 streams of data, each at a maximum of 150 megabits per second

802.11nMajor innovations in 802.11n-Changes to implementation of OFDM-Introduction of MIMO-MIMO power saving-Wider channel bandwidth-Antenna technology-Reduced support for backward compatibility under special circumstances to improve data throughput

802.11acWireless network bearer operating below 6GHzFour times the speed than 802.11n802.11ac is backward compatible with 802.11nAlso called as 5G Wi-Fi or VHTenables absolute maximum data rates of nearly 7 Gbps802.11acMU MIMO is implementedIs able to use up to eight spatial streams

802.11adWireless network bearer providing very high throughput at frequencies up to 60GHzAlso known as WiGigAims to provide data throughput speeds of up to 7 Gbpsused for very short range high volume data transfers802.11ad

Elements of a wifi systemElements of a WiFi SystemAccess Point (AP)

An access point acts as a base station which connects one or many wireless devices simultaneously to the internet.

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.Elements of a WiFi SystemWi-Fi Cards

Wi-Fi cards are embedded within the router and are responsible for accepting wireless signals and relaying information.Elements of a WiFi SystemSafeguards - Protect networks from unwanted users and keeps information secure.

How WiFi WorksLook for a Hotspot zoneWhen Wi-Fi enabled device encounters a hotspot the device can then connect to that network wirelessly.Many access points can be connected to each other via Ethernet cables to create a single large network.

How WiFi Works

SecurityWired Equivalent Privacy (WEP) encryption designed to protect against casual snooping but it is no longer considered secure. Tools such as AirSnort or Aircracking can quickly recover WEP encryption keys.Wi-Fi Protected Access (WPA) was then approved which uses Temporal Key Integrity Protocol TKIP. WPA2 is more secure using Advanced Encryption Standard was introduced in 2004 and is supported by most new Wi-Fi devices. It uses Advanced Encryption Standard (AES)Security1.WPA2 is the improved version of WPA2.WPA only supports TKIP encryption while WPA2 supports AES3.Theoretically, WPA2 cant be hacked while WPA is4.WPA2 requires more processing power than WPA

ENCRYPTIONEncryptionis the conversion of electronic data into another form, called ciphertext, which cannot be easily understood by anyone except authorized partiesWEP (Wired Equivalent Privacy)-uses RC4 (Rivest Cipher 4 also known asARC4orARCFOURmeaning Alleged RC4) for authentication and encryption -used standard 40-bit key then became maximum size is 104 bit-keys

Encryption is the conversion of electronic data into another form, called ciphertext, which cannot be easily understood by anyone except authorized parties.RC4 is a stream cipher. This means that for each bit of plaintext, it produces one bit of keystream and xors the two, to generate the ciphertext. The keystream is simply a stream of random numbers, generated from the RC4 algorithm.Aims to provide security by encryptingdata over radio waves so that it is protected as it is transmitted from one end point to another.

However, it has been found that WEP is not secured type of network security. Its security level is Low, easily cracked by active or passive attacks.RC4 is a stream cipher. This means that for each bit of plaintext, it produces one bit of keystream and xors the two, to generate the ciphertext. The keystream is simply a stream of random numbers, generated from the RC4 algorithm.In the most basic operation of a stream cipher, the algorithm is seeded with a key, such that the same key will always produce the same stream of random numbers. Since both the client and server know the key, they can produce the same keysteam. This allows the client to xor the plaintext with the keystream to produce the ciphertext, and the server to xor the ciphertext with the keystream to produce the plaintext again.

WLAN vs Wi-FiWLAN vs Wi-FiWLAN is a type of Computer Network.Wi-Fi is a trademark name to brand devices compliant to IEEE 802.11 standards.Devices in a WLAN essentially use Wi-Fi branded products.A Wi-Fi ready device means that it is ready for network operation within a WLANTHANK YOU!