# Introduction to wireless networking # Benefits of wireless technologies # Types of Wireless Networks: Ad-hoc mode, Infrastructure mode # Wireless network components: Wireless access point, NICs # Standard 802.11 # Wireless security protocols: WEP, WPA, 802.1X

1. Computer Networks
Wireless Networking
Date:
Department of Computer Engineering
Jain Group of Institution, Bangalore
Presented By:
Rubal Sagwal
Assistant Professor
Department of Computer Engineering
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2. Contents
• Introduction to wireless networking
• Types of Wireless Networks
• Wireless network components
• Standard 802.11
• Wireless security protocols
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3. Wireless Networking
Wireless Technology– Benefits of Wireless Technology
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4. Wireless Technology
• Wireless – No physical transmission device –
telecommunications in which electromagnetic waves
(rather than some form of wire) carry the signal over
part or all of the communication path.
• For Example:
• Wi-Fi
• Mobile phones
• GPS (Global positioning System)
• Cordless mouse/ keyboard
• Home entertainment system
• Wireless Ethernet – Bluetooth
https://www.youtube.com/watch?time_continue=42&v=u21lNHy0
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5. Benefits of Wireless Technology
• Advantage of a wireless network over a wired – users
can move around freely within the area of the network
with their laptops, handheld devices etc and get an
internet connection.
• Users are also able to share files and other resources
with other devices that are connected to the network
without having to be cabled to a port.
• Not having to lay lots of cables and put them through
walls etc – less cost.
• Wireless networks can sometimes handle a larger
amount of users because they are not limited by a
specific number of connection ports.
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6. Types of Wireless
Networks
Ad-hoc Mode – Infrastructure Mode
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7. Wireless Network
• IEEE 802.11 – Specification for wireless LAN
defined by IEEE – Covers physical and data link
layer.
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Architecture
BSS (Basic Service
Set)
ESS (Extended
Service Set)

8. 1. BSS (Basic Service Set)
• Building block of a wireless LAN.
• Made of – Stationary or Mobile service station –
Assess Point ( AP, Optional central base station).
• Without an AP – Ad-hoc Architecture
• Stand-alone network, can’t send data to other BSSs.
• Can form a network without the need of an AP.
• With an AP – Infrastructure Network
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9. 1. BSS (Basic Service Set)
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10. 2. ESS (Extended Service Set)
• Made up of two or more BSS with Aps.
• Connected through a distribution system (Wired
LAN).
• Distribution system – connects the APs in the BSSs.
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11. 2. ESS (Extended Service Set)
• It uses two station – Mobile and Stationary.
• Mobile station are normal station inside a BSS
• Stationary station are AP stations that are part of wired
LAN.
• When BSS are connected, the stations within reach
of one another can communicate without the use
of an AP.
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12. Station Type
1. No-Transition: either stationary (not moving) or
moving only inside a BSS.
2. BSS-transition: move from one BSS to another,
but the movement is confined inside one ESS.
3. ESS-transition: can move from one ESS to
another.
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13. Wireless Network
Components
Wireless Access Points – Wireless NICs
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14. Wireless Access Point
• A wireless access point (WAP) – a hardware device
or configured node on a local area network (LAN).
• That allows wireless capable devices and wired
networks to connect through a wireless standard,
including Wi-Fi or Bluetooth.
• WAPs feature antennae, which facilitate
connectivity between devices and the Internet or a
network.
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15. Wireless NIC
• A Wireless Network Card performs basically the
same operation as a normal network card, except
instead of operating through network cables, it
operates wirelessly.
• A W-NIC, just like other NICs, works on the Layer 1
and Layer 2 of the OSI Model.
• This card uses an antenna to
communicate via microwave radiate
on.
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16. Advantages of Wireless-NIC
• SETUP:
• Because wireless networks operate wirelessly, they
become very easy to setup and change.
• SECURITY:
• Today the security that wireless routers and cards offer,
is great, if you are willing to just go about setting it up.
• CHEAPER:
• wireless is so much cheaper than wired.
• SPEED:
• with the latest progressions, wireless is quickly
becoming just as fast or faster than their wired
counterparts.
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17. Wireless LAN Standards
IEEE 802.11a – IEEE 802.11b – IEEE 802.11g
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18. IEEE 802.11
• IEEE 802.11 is a set of media access control (MAC) (also
known as data link layer) and physical layer (PHY)
specifications for implementing wireless local area
network(WLAN).
• They are the world's most widely used wireless computer
networking standards, used in most home and office
networks to allow laptops, printers, and smartphones to talk
to each other and access the Internet without connecting
wires.
• They are created and maintained by the Institute of
Electrical and Electronics
Engineers (IEEE) LAN/MAN Standards Committee (IEEE 802).
• The base version of the standard was released in 1997, and
has had subsequent amendments.
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19. IEEE 802.11a
• The IEEE 802.11a standard is capable of producing a high level of
performance, and being in a band which is used less than the levels of
interference are less allowing high levels of performance.
• The 802.11a standard is alphabetically the first of the variety of 802.11
standards that are in widespread use today.
• Although 802.11a was ratified at the same time as 802.11b, it never
caught on in the same way despite the fact that it offered a much higher
data transfer rate.
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PARAMETER VALUE
Date of standard approval July 1999
Maximum data rate
(Mbps)
54
Typical data rate (Mbps) 25

20. IEEE 802.11b
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• IEEE 802.11b was the first wireless LAN standard to be
widely adopted and built in to many laptop computers
and other forms of equipment.
• The standard for 802.11b was ratified by the IEEE in July
1999 and the idea for wireless networking quickly
caught on with many W-Fi hotspots being set up so
that business people could access their emails and surf
the Internet as required when they were travelling.
• It was only after 802.11 was ratified and products
became available that W-Fi took off in a large way. Wi-
Fi hotspots were set up in many offices, hotels and
airports and the idea of using portable laptop
computers while travelling became far easier.

21. IEEE 802.11b Specifications
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• 802.11b boasts an impressive performance. It is
able to transfer data with raw data rates up to 11
Mbps, and has a good range, although not when
operating at its full data rate.
PARAMETER VALUE
Date of standard
approval
July 1999
Maximum data rate
(Mbps)
11
Typical data rate
(Mbps)
5

22. IEEE 802.11g
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• After the introduction of Wi-Fi with the 802.11a and
802.11b standards, the 802.11b standard became the most
popular operating in the 2.4 GHz ISM band.
• This standard proved to be the most popular despite the
faster operating speed of the a variant of the standard
because the cost of producing chips to operate at 2.4 GHz
were much less than ones to run at 5 GHz.
• In order to provide the higher speeds of 802.11a while
operating on the 2.4 GHz ISM band, a new standard was
introduced. Known as 802.11g, it soon took over from the b
standard.
• Even before the standard was ratified, 802.11g products
were available on the market, and before long it became the
dominant Wi-Fi technology.

23. IEEE 802.11g Specification
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• The 802.11g standard provided a number of
improvements over the 802.11b standard which
was its predecessor. The highlights of its
performance are given in the table below.
IEEE 802.11G WI-FI FEATURES
FEATURE 802.11G
Date of standard approval June 2003
Maximum data rate (Mbps) 54
Modulation CCK, DSSS, or OFDM
RF Band (GHz) 2.4
Channel width (MHz) 20

24. Wireless Security
Protocol
WEP – WPA – 802.1X
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25. 1. WEP (Wired Equivalent Privacy)
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• Wired Equivalent Privacy (WEP) is a security
algorithm for IEEE 802.11 wireless networks.
• Specified in the IEEE Wireless Fidelity (Wi-Fi)
standard, 802.11b, that is designed to provide a
wireless local area network (WLAN) with a level of
security and privacy comparable to what is usually
expected of a wired LAN.
• A wired local area network (LAN) is generally protected
by physical security mechanisms (For example,
controlled access to a building) that are effective for a
controlled physical environment, but may be ineffective
for WLANs because radio waves are not necessarily
bound by the walls containing the network.

26. WEP (Wired Equivalent Privacy)
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• WEP seeks to establish similar protection to that offered by
the wired network's physical security measures by
encrypting data transmitted over the WLAN.
Data encryption protects the vulnerable wireless link
between clients and access points.
• Once this measure has been taken, other typical LAN
security mechanisms such as password protection, end-to-
end encryption, virtual private networks (VPNs),
and authentication can be put in place to ensure privacy.

27. 2. Wi-Fi Protected Access (WPA)
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• Wi-Fi Protected Access (WPA) is a security standard for
users of computing devices equipped
with wireless internet connections.
• WPA was developed by the Wi-Fi Alliance to provide
more sophisticated data encryption and better
user authentication than Wired Equivalent Privacy
(WEP), the original Wi-Fi security standard.
• The new standard, which was ratified by the IEEE in
2004 as 802.11i , was designed to be backward-
compatible with WEP to encourage quick, easy
adoption. Network security professionals were able to
support WPA on many WEP-based devices with a
simple firmware update.

28. Wi-Fi Protected Access (WPA)
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• WPA has discrete modes for enterprise users and for
personal use.
• The enterprise mode, WPA-EAP, uses more stringent 802.1x
authentication with the Extensible Authentication Protocol
(EAP).
• The personal mode, WPA-PSK, uses preshared keys for
simpler implementation and management among
consumers and small offices.
• Enterprise mode requires the use of an authentication
server.
• WPA's encryption method is the Temporal Key Integrity
Protocol (TKIP).

29. Wi-Fi Protected Access (WPA)
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• TKIP includes a per-packet mixing function, a message integrity check,
an extended initialization vector and a re-keying mechanism.
• WPA provides strong user authentication based on 802.1x and the
Extensible Authentication Protocol (EAP). WPA depends on a central
authentication server, such as RADIUS, to authenticate each user.
• Software updates that allow both server and client computers to
implement WPA became widely available during 2003.
• Access points can operate in mixed WEP/WPA mode to support both
WEP and WPA clients. However, mixed mode effectively provides only
WEP-level security for all users.
• Home users of access points that use only WPA can operate in a special
home mode in which the user need only enter a password to be
connected to the access point. The password will trigger authentication
and TKIP encryption.

30. 3. 802.1X
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• The 802.1X standard is designed to enhance the
security of wireless local area networks (WLANs)
that follow the IEEE 802.11 standard.
• 802.1X provides an authentication framework for
wireless LANs, allowing a user to be authenticated
by a central authority.
• 802.1X uses an existing protocol, the Extensible
Authentication Protocol (EAP, RFC 2284), that works
on Ethernet, Token Ring, or wireless LANs, for
message exchange during the authentication
process.

31. 802.1X
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• In a wireless LAN with 802.1X, a user (known as the supplicant)
requests access to an access point (known as the authenticator).
• The access point forces the user (actually, the user's client
software) into an unauthorized state that allows the client to send
only an EAP start message.
• The access point returns an EAP message requesting the user's
identity.
• The client returns the identity, which is then forwarded by the
access point to the authentication server, which uses an
algorithm to authenticate the user and then returns an accept or
reject message back to the access point.
• Assuming an accept was received, the access point changes the
client's state to authorized and normal traffic can now take place.

32. Wireless security protocols: The difference between
WEP, WPA, WPA2
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