Download Slide 1

By
Kettly Joseph
&
Stephan Dubissette
Overview
• OSI Model
• Wireless LAN
– Definition
– Configuration
• Bluetooth
– Origin and Description
– Layers
• IEEE802.11
– Origin and Description
– layers
•
•
•
•
Differences and Similarities
Conclusion
Acknowledgement
References
OSI Model
Bluetooth
Example of a connection
between client and server
Wireless LAN
• Definition
– Wireless LAN:
• Is a flexible data communication network that is
used to transmit and receive data over the air by
using electromagnetic waves
• increases mobility.
• Offers the connectivity and the convenience of
wired LANs without the need for expensive wiring
or rewiring.
• Is sometimes more economical to use than wired
LAN
Wireless LAN
• WLAN configuration
– Wireless LAN network can be set up in the
four following ways:
•
•
•
•
Independent WLANs
Microcells and Roaming
Infrastructure WLANs
Ad Hoc
Bluetooth
• Origin
– the name “Bluetooth” came from a Viking whose
name was King-Harald Blatand
– Bluetooth was founded in 1994
•
L.M. Ericsson of Sweden
• Description
– Bluetooth:
– Is a Wireless Network Technology
– Is a Low power microwave link
• Use for short time data transfer
• Use for small indoor distances
– Devices communicate with each other in an Ad-Hoc
fashion
Layers (Bluetooth)
• Data Layer
– Bluetooth devices form overlapping
networks called piconets
– Each piconet can carry a maximum
of eight devices
– There are two types of packet
transfer:
• Asynchronous Connectionless (ACL)
links for data transmission
• Synchronous Connection oriented
(SCO) for audio/ voice transmission.
– The Bluetooth data rate has a
gross rate of 1 Mbps.
Layers (Bluetooth)
• Physical Layer
Bluetooth:
• Operates in the 2.4 GHz unlicensed ISM
(Industrial – Scientific – Medical) band
• Uses
– Gaussian Frequency Shift Keying(GFSK) .
– Frequency hopped spread spectrum FHSS) for
transmits of data
– Data rate is relatively slow at 1 Mbps
– Sensitivity Level of -70 dB
IEEE802.11
• Origin and description
– IEEE 802.11 is the standard set by the
IEEE for wireless network connections
– Target areas for IEEE 802.11 are inside
buildings and also outdoor uses.
– There is support for most market
applications
– Three different data/voice integration
• 802.11a : 5Ghz OFDM
• 802.11b : 2,4GHz DSSS
• 802.11g : 5GHz OFDM
• Data Layer
Layers (IEEE802.11)
– two different ways to configure a network in Wireless
LAN:
– Ad-hoc
• there is no structure
• order is maintain using algorithm like the
spokesman election algorithm
– infrastructure
• network uses fixed network access point
• To widen the wireless LAN the access points are
sometimes connected from one node to the other
one by connecting them to landlines.
Layers (IEEE802.11)
• Physical Layer
– Handles the transmission of data between
nodes
– Use DSSS, FHSS( 2.4 - 2.4835 GHz)
– Use IR pulse position modulation (300 428,000 GHz).
– Medium access control (MAC) layers
• Set of protocols responsible for maintaining
order in the use of a shared medium.
(CSMA/CA) or VCSM
Virtual carrier Sense 's mechanism
Problem and Solution
Layers (IEEE802.11)
• Network Layer
– Handle Security in the network by using:
– Mobile IP which
• Is a way to attain wireless networking
• Does not change when it moves form a home
network to a foreign network.
• Maintains connection with the rest of the network
by implementing the forwarding routine
– Disadvantage
• need of storing and forwarding of packets while the
mobile agent is on neither the home nor the foreign
network
• IP works only for IPv4
Differences and Similarities
• Differences
– Bluetooth use GFSK (Gaussian Frequency Shift
Keying) as opposed to CCK (Complementary Code
Keying) in 802.11
– 802.11 users have much more flexibility in using their
devices.
• The range of most Bluetooth devices is approximately 10 m
(33ft). Whereas 802.11has an outdoor range of 300m (1000 ft).
– Bluetooth uses Frequency Hopping and 802.11b uses
DSSS (Direct Sequence Spread Spectrum)
– All 802.11 addressing and access is taken from the
Ethernet standard. Whereas, all the addressing is
handled by the master of the piconets for Bluetooth.
– Bluetooth is being used for device to device data
transfer.
– 802.11 has become more of an access point for a
computer to get on a wired backbone
Differences and Similarities
• Similarities
– Bluetooth and 802.11 are both wireless
'network' technologies.
– they both operate in the same 2.4 GHz ISM
band.
– They both are capable of creating ad-hoc
networks
– They both connect electronic devices without
any wires
Conclusion
• These two technologies had in fact really
different uses and could both add something to
the wireless market
• Today, attempt to make both Bluetooth and
IEEE802.11 work together on a same network
• Bluetooth hops through frequencies 640 times
faster than 802.11 which causes interference.
• To reduce the possibility of interference between
Bluetooth and 802.11 products, consider using
frequency hopping instead of direct sequence
IEEE 802.11 wireless LAN radio cards and
access points.
• The relatively low power signals of the Bluetooth
devices diminish rapidly over longer distances.
Acknowledgements
• Our thanks go to:
– Prof. Yao Wang for her time and patience
– For our T.A
– Students of the ee3414 class for listening to
us
References
• http://www.ee.mtu.edu/~dmarcham/bluetooth/ref.html
• Standards and protocol - IEEE802.11b - by Al petrick
[Online]. Available:
http://www.csdmag.com/main/2000/06/0006
stand.htm
• Bluetooth and IEEE802.11 - by Brent Miller ( October 2001)[Online]. Available :
http://www-106.ibm.com/developerworks/wireless/library/wiphone/?t=gr,p=WirelessBuds
• 10meters.com (2000-2001) Bluetooth and 802.11: A
Tale of Two Technologies. 10Meters.com, San Francisco, CA.
[Online]. Available:
http://www.10meters.com/blue_802.htmlhttp://www.amigocom.com/
News/news1-2-03.pdf
• http://www.amigocom.com/News/news1-2-03.pdf
• http://www.dcs.napier.ac.uk/~bill/cisco_presentation/osi31.pdf