Wi-Fi (or wireless fidelity) refers to wireless local area network (WLAN) technology based on the IEEE 802.11 standards. It allows electronic devices to connect to a wireless network, mainly using 2.4GHz UHF and 5GHz SHF radio frequencies. Wi-Fi uses access points that broadcast its SSID to wireless devices, which can then connect to the internet or wired network. Common Wi-Fi technologies include 802.11b, 802.11a, and 802.11g. Security measures for Wi-Fi networks include authentication, encryption, and restricting access through passwords or MAC address filtering to prevent unauthorized access.
Wi-Fi For Beginners - Module 1- What is WiFi?Nigel Bowden
Slides from the Wi-Fi For Beginners Podcast. These are the slides from module one of a series of podcasts looking at the basics of wireless LAN (WiFi) networking. You can find the podcast at WiFiForBeginners.com and on iTunes
Slides from the Wi-Fi For Beginners Podcast. These are the slides from module three of a series of podcasts looking at basics wireless LAN (WiFi) networking. In this module, we take a look at wireless access points (APs) and their role in a WLAN. You can find the podcast at WiFiForBeginners.com and on iTunes
WiFi For Beginners Module 2 - RF BasicsNigel Bowden
Slides from the Wi-Fi For Beginners Podcast. These are the slides from module two of a series of podcasts looking at the basics wireless LAN (WiFi) networking. In this module we take a look at the basics of RF (radio frequency) from a WiFi perpectiveYou can find the podcast at WiFiForBeginners.com and on iTunes
Wi-Fi For Beginners - Module 1- What is WiFi?Nigel Bowden
Slides from the Wi-Fi For Beginners Podcast. These are the slides from module one of a series of podcasts looking at the basics of wireless LAN (WiFi) networking. You can find the podcast at WiFiForBeginners.com and on iTunes
Slides from the Wi-Fi For Beginners Podcast. These are the slides from module three of a series of podcasts looking at basics wireless LAN (WiFi) networking. In this module, we take a look at wireless access points (APs) and their role in a WLAN. You can find the podcast at WiFiForBeginners.com and on iTunes
WiFi For Beginners Module 2 - RF BasicsNigel Bowden
Slides from the Wi-Fi For Beginners Podcast. These are the slides from module two of a series of podcasts looking at the basics wireless LAN (WiFi) networking. In this module we take a look at the basics of RF (radio frequency) from a WiFi perpectiveYou can find the podcast at WiFiForBeginners.com and on iTunes
In order for the Internet of Things to function properly, a reliable wireless technology needs to be available. Radio frequencies are some of the most popular and effective means for IoT communication.
TangoTec is a system vendor of next generation networking solutions for IP-based entertainment distribution over any existing wire infrastructures (coaxial, power lines, telephone lines).
For more information and to set a meeting at IBC 2011: http://www.israelmediainnovations.com
802.11ac: Technologies and Deployment Strategies with FarPoint GroupSavvius, Inc
Hear Craig Mathias of Farpoint Group and Jay Botelho of WildPackets discussing 802.11ac: Technologies and Deployment Strategies, where they will offer their insights on the importance of 802.11ac now and in the future.
With a wide variety of enterprise-class 802.11ac products now appearing in the market, IT leaders have some interesting questions to consider: What are the key features and benefits of 802.11ac? Should 802.11ac be deployed now, or later? How should these deployments be staged? What about situations where 802.11ac isn't scheduled for near-term operation, but potential threats like rogue 802.11ac APs demand near-term solutions?
A brief summary of the LPWAN wireless protocols and a more technical overview of LoRa (Long-Range) starting from PHY and throughout the rest of the LoRaWAN stack emphasizing its implications on IoT platforms.
Talk held at:
Winter School 2017 on "Internet of Things: Security, Communication & Application Challenges" organized by the Computing Systems, Security and Networks (CSSN) Research Lab of the Alexander TEI of Thessaloniki (ATEITHE) and the IEEE ATEITHE Student Branch
Wi-Fi For Beginners - Module 5- Wi-Fi ClientsNigel Bowden
Slides from the Wi-Fi For Beginners Podcast. These are the slides from module five of a series of podcasts looking at the basics of wireless LAN (WiFi) networking. In this module we take a look at WiFi clients. You can find the podcast at WiFiForBeginners.com and on iTunes
In order for the Internet of Things to function properly, a reliable wireless technology needs to be available. Radio frequencies are some of the most popular and effective means for IoT communication.
TangoTec is a system vendor of next generation networking solutions for IP-based entertainment distribution over any existing wire infrastructures (coaxial, power lines, telephone lines).
For more information and to set a meeting at IBC 2011: http://www.israelmediainnovations.com
802.11ac: Technologies and Deployment Strategies with FarPoint GroupSavvius, Inc
Hear Craig Mathias of Farpoint Group and Jay Botelho of WildPackets discussing 802.11ac: Technologies and Deployment Strategies, where they will offer their insights on the importance of 802.11ac now and in the future.
With a wide variety of enterprise-class 802.11ac products now appearing in the market, IT leaders have some interesting questions to consider: What are the key features and benefits of 802.11ac? Should 802.11ac be deployed now, or later? How should these deployments be staged? What about situations where 802.11ac isn't scheduled for near-term operation, but potential threats like rogue 802.11ac APs demand near-term solutions?
A brief summary of the LPWAN wireless protocols and a more technical overview of LoRa (Long-Range) starting from PHY and throughout the rest of the LoRaWAN stack emphasizing its implications on IoT platforms.
Talk held at:
Winter School 2017 on "Internet of Things: Security, Communication & Application Challenges" organized by the Computing Systems, Security and Networks (CSSN) Research Lab of the Alexander TEI of Thessaloniki (ATEITHE) and the IEEE ATEITHE Student Branch
Wi-Fi For Beginners - Module 5- Wi-Fi ClientsNigel Bowden
Slides from the Wi-Fi For Beginners Podcast. These are the slides from module five of a series of podcasts looking at the basics of wireless LAN (WiFi) networking. In this module we take a look at WiFi clients. You can find the podcast at WiFiForBeginners.com and on iTunes
Penerapan Metode Backpropagation Neural Network untuk Memprediksi Produksi AirWaka Benington
Penelitian ini bertujuan untuk menerapkan Jaringan Syaraf Tiruan Backpropagation untuk memprediksi jumlah produksi air. Data yang diperolah berasal dari laporan bulanan PDAM Tirta Bina Rantauprapat selama 5 tahun, mulai dari tahun 2010 sampai dengan tahun 2014. Variabel masukan yang digunakan adalah data jumlah pelanggan berdasarkan kelompok rumah tangga, volume kebocoran air di pengolahan, volume distribusi air, volume air terjual dan volume kehilangan air. Sedangkan yang menjadi variabel target adalah volume produksi air. Berdasarkan hasil penelitian, diperoleh sebuah model arsitektur prediksi dengan jumlah neuron lapisan masukan 5, jumlah neuron lapisan tersembunyi 3, jumlah neuron lapisan keluaran 1, dengan nilai MSE 0.000999, MAE 0.017096, dan rata-rata nilai akurasi sebesar 98,29 %.
"Kraft der Alpenkräuter" - so der Titel der Brand Page von Sixtus auf der Huffington Post Deutschland. Wie erfolgreich die Kampagne lief, zeigen die Ergebnisse unserer neuesten kampagnenbegleitenden Werbewirkungsstudie.
In the slide, Eric Enge will show you what Penguin 4.0 is and how it can impact your site.
This slide is shown State of Search in Dallas, TX in November, 2016
Die Neuauflage der bereits im Jahr 2013 durchgeführten Studie zeigt, wie rasant sich die Social Media Welt weiterentwickelt und wo die Reise mit facebook, Twitter & Co hingeht.
Sport-Gaming, Fitness im Park, trainingsbegleitende Apps oder Online-Fitnessstudios - in unserer aktuellen Social Trends Studie beleuchten wir die unterschiedlichsten Trends rund um das Thema Sport und zeigen: Sport ist heute sozial und digital.
This is a ppt about the recent trends in tech and wireless communication. As the is good document to read we are requesting to study the wireless communal harmony and peace to you. Aster that I have a great day and I will be available from June to September to December to February to the same here to visit our frequently asked questions about HTML5.
And ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha Akshar cholk Thai ne na jato ko bhi 6 baje uthta hai ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye shikhar ki aur batao ki nai dunia epaper ab naye 5.
This presentation gives brief description of Wi-Fi Technolgy, standards, applications,topologies, how Wi-Fi network works, security,advantages and innovations.
When setting up and maintaining Wi-Fi home networks, consider these tips for maximizing the security of the computers and data on these networks.
Securing Wireless Networks by maximizing the security of 802.11 standard and minimizing the Risk on Wireless network
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
4. IntroductionIntroduction
• Wireless Technology is an alternative to WiredWireless Technology is an alternative to Wired
Technology, which is commonly used, forTechnology, which is commonly used, for
connecting devices in wireless mode.connecting devices in wireless mode.
• Wi-Fi (Wireless Fidelity) is a generic term thatWi-Fi (Wireless Fidelity) is a generic term that
refers to the IEEE 802.11 communicationsrefers to the IEEE 802.11 communications
standard for Wireless Local Area Networksstandard for Wireless Local Area Networks
(WLANs).(WLANs).
• Wi-Fi Network connect computers to each other,Wi-Fi Network connect computers to each other,
to the internet and to the wired network.to the internet and to the wired network.
5. The Wi-Fi TechnologyThe Wi-Fi Technology
Wi-Fi Networks use Radio Technologies toWi-Fi Networks use Radio Technologies to
transmit & receive data at high speed:transmit & receive data at high speed:
• IEEE 802.11bIEEE 802.11b
• IEEE 802.11aIEEE 802.11a
• IEEE 802.11gIEEE 802.11g
6. IEEE 802.11bIEEE 802.11b
• Appear in late 1999Appear in late 1999
• Operates at 2.4GHz radio spectrumOperates at 2.4GHz radio spectrum
• 11 Mbps (theoretical speed) - within 30 m Range11 Mbps (theoretical speed) - within 30 m Range
• 4-6 Mbps (actual speed)4-6 Mbps (actual speed)
• 100 -150 feet range100 -150 feet range
• Most popular, Least ExpensiveMost popular, Least Expensive
• Interference from mobile phones and BluetoothInterference from mobile phones and Bluetooth
devices which can reduce the transmissiondevices which can reduce the transmission
speed.speed.
7. IEEE 802.11aIEEE 802.11a
• Introduced in 2001Introduced in 2001
• Operates at 5 GHz (less popular)Operates at 5 GHz (less popular)
• 54 Mbps (theoretical speed)54 Mbps (theoretical speed)
• 15-20 Mbps (Actual speed)15-20 Mbps (Actual speed)
• 50-75 feet range50-75 feet range
• More expensiveMore expensive
• Not compatible with 802.11bNot compatible with 802.11b
8. IEEE 802.11gIEEE 802.11g
• Introduced in 2003Introduced in 2003
• Combine the feature of both standardsCombine the feature of both standards
(a,b)(a,b)
• 100-150 feet range100-150 feet range
• 54 Mbps Speed54 Mbps Speed
• 2.4 GHz radio frequencies2.4 GHz radio frequencies
• Compatible with ‘b’Compatible with ‘b’
9. 802.11 Physical Layer802.11 Physical Layer
There are three sublayers in physical layer:There are three sublayers in physical layer:
• Direct Sequence Spread Spectrum (DSSS)Direct Sequence Spread Spectrum (DSSS)
• Frequency Hoping Spread Spectrum (FHSS)Frequency Hoping Spread Spectrum (FHSS)
• Diffused Infrared (DFIR) - Wide angleDiffused Infrared (DFIR) - Wide angle
10. DSSSDSSS
• Direct sequence signaling technique divides the 2.4 GHz band intoDirect sequence signaling technique divides the 2.4 GHz band into
11 22-MHz channels. Adjacent channels overlap one another22-MHz channels. Adjacent channels overlap one another
partially, with three of the 11 being completely non-overlapping.partially, with three of the 11 being completely non-overlapping.
Data is sent across one of these 22 MHz channels without hoppingData is sent across one of these 22 MHz channels without hopping
to other channels.to other channels.
11. IEEE 802.11 Data Link LayerIEEE 802.11 Data Link Layer
The data link layer consists of two sublayers :The data link layer consists of two sublayers :
• Logical Link Control (LLC)Logical Link Control (LLC)
• Media Access Control (MAC).Media Access Control (MAC).
802.11 uses the same 802.2 LLC and 48-bit addressing as other802.11 uses the same 802.2 LLC and 48-bit addressing as other
802 LANs, allowing for very simple bridging from wireless to802 LANs, allowing for very simple bridging from wireless to
IEEE wired networks, but the MAC is unique to WLANs.IEEE wired networks, but the MAC is unique to WLANs.
12. 802.11 Media Access Control802.11 Media Access Control
• Carrier Sense Medium Access with collisionCarrier Sense Medium Access with collision
avoidance protocol (CSMA/CA)avoidance protocol (CSMA/CA)
• Listen before talkingListen before talking
• Avoid collision by explicit Acknowledgement (ACK)Avoid collision by explicit Acknowledgement (ACK)
• Problem: additional overhead of ACK packets, soProblem: additional overhead of ACK packets, so
slow performanceslow performance
• Request to Send/Clear to SendRequest to Send/Clear to Send
(RTS/CTS) protocol(RTS/CTS) protocol
• Solution for “hidden node” problemSolution for “hidden node” problem
• Problem: Adds additional overhead by temporarilyProblem: Adds additional overhead by temporarily
reserving the medium, so used for large size packetsreserving the medium, so used for large size packets
only retransmission would be expensiveonly retransmission would be expensive
13. 802.11 Media Access802.11 Media Access
Control(cont.)Control(cont.)
• Power ManagementPower Management
• MAC supports power conservation to extend the battery life ofMAC supports power conservation to extend the battery life of
portable devicesportable devices
• Power utilization modesPower utilization modes
• Continuous Aware ModeContinuous Aware Mode
• Radio is always on and drawing powerRadio is always on and drawing power
• Power Save Polling ModePower Save Polling Mode
• Radio is “dozing” with access point queuing any data for itRadio is “dozing” with access point queuing any data for it
• The client radio will wake up periodically in time to receiveThe client radio will wake up periodically in time to receive
regularregular beaconbeacon signals from the access point.signals from the access point.
• The beacon includes information regarding which stations haveThe beacon includes information regarding which stations have
traffic waiting for themtraffic waiting for them
• The client awake on beacon notification and receive its dataThe client awake on beacon notification and receive its data
14. 802.11 Media Access802.11 Media Access
Control(cont.)Control(cont.)
• FragmentationFragmentation
• CRC checksumCRC checksum
• Each pkt has a CRC checksum calculatedEach pkt has a CRC checksum calculated
and attached to ensure that the data was notand attached to ensure that the data was not
corrupted in transitcorrupted in transit
• Association & RoamingAssociation & Roaming
15. Elements of a WI-FI NetworkElements of a WI-FI Network
• Access Point (AP) -Access Point (AP) - The AP is a wireless LANThe AP is a wireless LAN
transceiver or “base station” that can connect one or manytransceiver or “base station” that can connect one or many
wireless devices simultaneously to the Internet.wireless devices simultaneously to the Internet.
• Wi-Fi cards -Wi-Fi cards - They accept the wireless signal and relayThey accept the wireless signal and relay
information.They can be internal and external.(e.g PCMCIAinformation.They can be internal and external.(e.g PCMCIA
Card for Laptop and PCI Card for Desktop PC)Card for Laptop and PCI Card for Desktop PC)
• Safeguards -Safeguards - Firewalls and anti-virus software protectFirewalls and anti-virus software protect
networks from uninvited users and keep information secure.networks from uninvited users and keep information secure.
16. How a Wi-Fi Network WorksHow a Wi-Fi Network Works
• Basic concept is same as Walkie talkies.Basic concept is same as Walkie talkies.
• A Wi-Fi hotspot is created by installing an access pointA Wi-Fi hotspot is created by installing an access point
to an internet connection.to an internet connection.
• An access point acts as a base station.An access point acts as a base station.
• When Wi-Fi enabled device encounters a hotspot theWhen Wi-Fi enabled device encounters a hotspot the
device can then connect to that network wirelessly.device can then connect to that network wirelessly.
• A single access point can support up to 30 users andA single access point can support up to 30 users and
can function within a range of 100 – 150 feet indoors andcan function within a range of 100 – 150 feet indoors and
up to 300 feet outdoors.up to 300 feet outdoors.
• Many access points can be connected to each other viaMany access points can be connected to each other via
Ethernet cables to create a single large network.Ethernet cables to create a single large network.
18. AP-based topologyAP-based topology
• The client communicate through Access Point.The client communicate through Access Point.
• BSA-RF coverage provided by an AP.BSA-RF coverage provided by an AP.
• ESA-It consists of 2 or more BSA.ESA-It consists of 2 or more BSA.
• ESA cell includes 10-15% overlap to allowESA cell includes 10-15% overlap to allow
roaming.roaming.
19. Peer-to-peer topologyPeer-to-peer topology
• AP is not required.AP is not required.
• Client devices withinClient devices within
a cell cana cell can
communicate directlycommunicate directly
with each other.with each other.
• It is useful for settingIt is useful for setting
up of a wirelessup of a wireless
network quickly andnetwork quickly and
easily.easily.
20. Point-to-multipoint bridge topologyPoint-to-multipoint bridge topology
This is used to connect a LAN in one building to a LANsThis is used to connect a LAN in one building to a LANs
in other buildings even if the buildings are milesin other buildings even if the buildings are miles
apart.These conditions receive a clear line of sightapart.These conditions receive a clear line of sight
between buildings. The line-of-sight range varies basedbetween buildings. The line-of-sight range varies based
on the type of wireless bridge and antenna used as wellon the type of wireless bridge and antenna used as well
as the environmental conditions.as the environmental conditions.
24. Wi-Fi ApplicationsWi-Fi Applications
• HomeHome
• Small Businesses or SOHOSmall Businesses or SOHO
• Large Corporations & CampusesLarge Corporations & Campuses
• Health CareHealth Care
• Wireless ISP (WISP)Wireless ISP (WISP)
• TravellersTravellers
25. Wi-Fi Security ThreatsWi-Fi Security Threats
• Wireless technology doesn’t remove anyWireless technology doesn’t remove any
old security issues, but introduces newold security issues, but introduces new
onesones
• EavesdroppingEavesdropping
• Man-in-the-middle attacksMan-in-the-middle attacks
• Denial of ServiceDenial of Service
26. EavesdroppingEavesdropping
• Easy to perform, almost impossible to detectEasy to perform, almost impossible to detect
• By default, everything is transmitted in clear textBy default, everything is transmitted in clear text
• Usernames, passwords, content ...Usernames, passwords, content ...
• No security offered by the transmission mediumNo security offered by the transmission medium
• Different tools available on the internetDifferent tools available on the internet
• Network sniffers, protocol analysers . . .Network sniffers, protocol analysers . . .
• Password collectorsPassword collectors
• With the right equipment, it’s possible toWith the right equipment, it’s possible to
eavesdrop traffic from few kilometers awayeavesdrop traffic from few kilometers away
27. MITM AttackMITM Attack
1.1. Attacker spoofes aAttacker spoofes a
disassociate messagedisassociate message
from the victimfrom the victim
2.2. The victim starts toThe victim starts to
look for a new accesslook for a new access
point, and the attackerpoint, and the attacker
advertises his own APadvertises his own AP
on a different channel,on a different channel,
using the real AP’susing the real AP’s
MAC addressMAC address
3.3. The attacker connectsThe attacker connects
to the real AP usingto the real AP using
victim’s MAC addressvictim’s MAC address
28. Denial of ServiceDenial of Service
• Attack on transmission frequecy usedAttack on transmission frequecy used
• Frequency jammingFrequency jamming
• Not very technical, but worksNot very technical, but works
• Attack on MAC layerAttack on MAC layer
• Spoofed deauthentication / disassociation messagesSpoofed deauthentication / disassociation messages
• can target one specific usercan target one specific user
• Attacks on higher layer protocol (TCP/IP protocol)Attacks on higher layer protocol (TCP/IP protocol)
• SYN FloodingSYN Flooding
29. Wi-Fi SecurityWi-Fi Security
The requirements for Wi-Fi networkThe requirements for Wi-Fi network
security can be broken down into twosecurity can be broken down into two
primary components:primary components:
• AuthenticationAuthentication
User AuthenticationUser Authentication
Server AuthenticationServer Authentication
• PrivacyPrivacy
30. AuthenticationAuthentication
• Keeping unauthorized users off the networkKeeping unauthorized users off the network
• User AuthenticationUser Authentication
• Authentication Server is usedAuthentication Server is used
• Username and passwordUsername and password
• Risk:Risk:
• Data (username & password) send before secure channelData (username & password) send before secure channel
establishedestablished
• Prone to passive eavesdropping by attackerProne to passive eavesdropping by attacker
• SolutionSolution
• Establishing a encrypted channel before sending usernameEstablishing a encrypted channel before sending username
and passwordand password
31. Authentication (cont..)Authentication (cont..)
• Server AuthenticationServer Authentication
• Digital Certificate is usedDigital Certificate is used
• Validation of digital certificate occursValidation of digital certificate occurs
automatically within client softwareautomatically within client software
32. Wi-Fi Security TechniquesWi-Fi Security Techniques
• Service Set Identifier (SSID)Service Set Identifier (SSID)
• Wired Equivalent Privacy (WEP)Wired Equivalent Privacy (WEP)
• 802.1X Access Control802.1X Access Control
• Wireless Protected Access (WPA)Wireless Protected Access (WPA)
• IEEE 802.11iIEEE 802.11i
33. Service Set Identifier (SSID)Service Set Identifier (SSID)
• SSID is used to identify an 802.11 networkSSID is used to identify an 802.11 network
• It can be pre-configured or advertised inIt can be pre-configured or advertised in
beacon broadcastbeacon broadcast
• It is transmitted in clear textIt is transmitted in clear text
• Provide very little securityProvide very little security
34. Wired Equivalent Privacy (WEP)Wired Equivalent Privacy (WEP)
• Provide same level of security as by wired networkProvide same level of security as by wired network
• Original security solution offered by the IEEE 802.11Original security solution offered by the IEEE 802.11
standardstandard
• Uses RC4 encryption with pre-shared keys and 24 bitUses RC4 encryption with pre-shared keys and 24 bit
initialization vectors (IV)initialization vectors (IV)
• key schedule is generated by concatenating the sharedkey schedule is generated by concatenating the shared
secret key with a random generated 24-bit IVsecret key with a random generated 24-bit IV
• 32 bit ICV (Integrity check value)32 bit ICV (Integrity check value)
• No. of bits in keyschedule is equal to sum of length ofNo. of bits in keyschedule is equal to sum of length of
the plaintext and ICVthe plaintext and ICV
35. Wired Equivalent Privacy (WEP)Wired Equivalent Privacy (WEP)
(cont.)(cont.)
• 64 bit preshared key-WEP64 bit preshared key-WEP
• 128 bit preshared key-WEP2128 bit preshared key-WEP2
• Encrypt data only between 802.11 stations.once it entersEncrypt data only between 802.11 stations.once it enters
the wired side of the network (between access point)the wired side of the network (between access point)
WEP is no longer validWEP is no longer valid
• Security Issue with WEPSecurity Issue with WEP
• Short IVShort IV
• Static keyStatic key
• Offers very little security at allOffers very little security at all
36. 802.1x Access Control802.1x Access Control
• Designed as a general purpose network access control mechanismDesigned as a general purpose network access control mechanism
• Not Wi-Fi specificNot Wi-Fi specific
• Authenticate each client connected to AP (for WLAN) or switch portAuthenticate each client connected to AP (for WLAN) or switch port
(for Ethernet)(for Ethernet)
• Authentication is done with the RADIUS server, which ”tells” theAuthentication is done with the RADIUS server, which ”tells” the
access point whether access to controlled ports should be allowedaccess point whether access to controlled ports should be allowed
or notor not
• AP forces the user into an unauthorized stateAP forces the user into an unauthorized state
• user send an EAP start messageuser send an EAP start message
• AP return an EAP message requesting the user’s identityAP return an EAP message requesting the user’s identity
• Identity send by user is then forwared to the authentication server by APIdentity send by user is then forwared to the authentication server by AP
• Authentication server authenticate user and return an accept or rejectAuthentication server authenticate user and return an accept or reject
message back to the APmessage back to the AP
• If accept message is return, the AP changes the client’s state toIf accept message is return, the AP changes the client’s state to
authorized and normal traffic flowsauthorized and normal traffic flows
38. Wireless Protected Access (WPA)Wireless Protected Access (WPA)
• WPAWPA is a specification of standard based, interoperable securityis a specification of standard based, interoperable security
enhancements that strongly increase the level of data protectionenhancements that strongly increase the level of data protection
and access control for existing and future wireless LAN system.and access control for existing and future wireless LAN system.
• User AuthenticationUser Authentication
• 802.1x802.1x
• EAPEAP
• TKIP (Temporal Key Integrity Protocol) encryptionTKIP (Temporal Key Integrity Protocol) encryption
• RC4, dynamic encryption keys (session based)RC4, dynamic encryption keys (session based)
• 48 bit IV48 bit IV
• per packet key mixing functionper packet key mixing function
• Fixes all issues found from WEPFixes all issues found from WEP
• Uses Message Integrity Code (MIC) MichaelUses Message Integrity Code (MIC) Michael
• Ensures data integrityEnsures data integrity
• Old hardware should be upgradeable to WPAOld hardware should be upgradeable to WPA
39. Wireless Protected Access (WPA)Wireless Protected Access (WPA)
(cont.)(cont.)
• WPA comes in two flavorsWPA comes in two flavors
• WPA-PSKWPA-PSK
• use pre-shared keyuse pre-shared key
• For SOHO environmentsFor SOHO environments
• Single master key used for all usersSingle master key used for all users
• WPA EnterpriseWPA Enterprise
• For large organisationFor large organisation
• Most secure methodMost secure method
• Unique keys for each userUnique keys for each user
• Separate username & password for each userSeparate username & password for each user
40. WPA and Security ThreatsWPA and Security Threats
• Data is encryptedData is encrypted
• Protection against eavesdropping and man-in-the-Protection against eavesdropping and man-in-the-
middle attacksmiddle attacks
• Denial of ServiceDenial of Service
• Attack based on fake massages can not be used.Attack based on fake massages can not be used.
• As a security precaution, if WPA equipment seesAs a security precaution, if WPA equipment sees
two packets with invalid MICs within a second, ittwo packets with invalid MICs within a second, it
disassociates all its clients, and stops all activity fordisassociates all its clients, and stops all activity for
a minutea minute
• Only two packets a minute enough to completelyOnly two packets a minute enough to completely
stop a wireless networkstop a wireless network
41. 802.11i802.11i
• Provides standard for WLAN securityProvides standard for WLAN security
• AuthenticationAuthentication
• 802.1x802.1x
• Data encryptionData encryption
• AES protocol is usedAES protocol is used
• Secure fast handoff-This allow roamingSecure fast handoff-This allow roaming
between APs without requiring client tobetween APs without requiring client to
fully reauthenticate to every AP.fully reauthenticate to every AP.
• Will require new hardwareWill require new hardware
42. AdvantagesAdvantages
• MobilityMobility
• Ease of InstallationEase of Installation
• FlexibilityFlexibility
• CostCost
• ReliabilityReliability
• SecuritySecurity
• Use unlicensed part of the radio spectrumUse unlicensed part of the radio spectrum
• RoamingRoaming
• SpeedSpeed