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Basics of Wireless Networks: Key Concepts & Protocols

Learn about wireless network fundamentals, access technologies, and key issues and illustrate various aspects like interference, routing, and security. Explore different wireless network architectures and classifications.

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Basics of Wireless Networks: Key Concepts & Protocols

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  1. Chapter 2 Basics of Wireless Networks TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  2. Learningobjectives To understandwireless networks To knowthe access technologies To studyproblemssuchasinterference, multi-path propagation,pathloss, batterylife,etc. To illustrateissueslikechannelallocation, routing, mobility,security,powermanagement,etc. TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  3. Wirelessnetworks Wired network Wire as communication High data rate No mobility medium Wireless network Radio waves and Less data rate Highly portable Mobility air as a medium TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  4. Wireless networks (Contd..) Provide Internet inexpensive and rapidconnectionsetup with Restrictedbydistance Overlapping radio cells to provide connectivity TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  5. Wireless network architecture It consists of mobile hosts, fixed hosts, access stations (BS), corenetworktosupportmobilityandswitching. TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  6. Wireless network architecture (Contd..) Mobile host Laptop,mobilephone, PDA,notebook,etc.can move from one place to another place while maintainingconnection with wirelessnetwork. Fixed wireless host Cannot move but the medium is radio waves. Example: wireless web servers, printers, etc. Access Network Consists of access stations (BS) which provide servicesto hostsreachablefromit. TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  7. Wireless network architecture (Contd..) Core Network Consists of active components that perform data switching betweenaccess stations (BS), and provide location and mobility services. Facilitatescommunicationfrommobilehostto mobile host, mobile host fixed to wired node, fixed host, host etc. to wired node, host to mobile TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  8. Classificationof wireless networks Wireless Wireless Wireless Wireless Wireless body area networks personal area networks local area networks metropolitan area networks wide area networks such as and GSM or CDMA cellular networks Satellite networks and broadband accessnetworks TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  9. Classification of wireless (Contd..) networks TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  10. Classification of wireless (Contd..) Wireless Body Area Network (WBAN) networks Max. signalrange 2 meters Interconnecting respective devices within the surface of the body    TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  11. Classification of wireless (Contd..) networks Wireless Body Area Network (WBAN) TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  12. Classification of wireless (Contd..) networks WirelessPersonalAreaNetwork (WPAN) Max. signal range of 10 meters TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  13. Classification of wireless networks (Contd..) Wireless Local Area Network (WLAN) • Signalrangeis ≈100meters. • Also called the Wireless Fidelity (Wi-Fi or IEEE 802.11) TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  14. Recall: an exampleof wired LAN Laptop Laptop Laptop Server Printer Work Station Work Work Station Station TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  15. An example of wireless LAN A user is connected if he/she is in the coverage area of a cell Each cell operates at a different frequency Work Station Laptop Laptop Laptop Laptop Laptop Access Point Access Point Access Point Server Printer Access Point Access Point Access Point Work Station Work Station Work Station Work Station Work Station TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  16. Classification of wireless networks (Contd..) Wireless Metropolitan Area Network (WMAN) Signal range of approximately 5 km to 20 km (recently up to 50 km) Often called Worldwide Interoperability for Microwave Access (WiMAX or IEEE 802.16) Wi-Fi users may be connected to the WiMAX network WiMAXBS Mobile devices might have built in WiMAX adapter or may be externally plugged WMAN might be owned and operated by organizations or public institutions TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  17. Classification of wireless networks (Contd..) Wireless Wide Area Network (WWAN) Use network infrastructure of mobile operators. Cover wide area much wider than groups mentioned above. Usecellularnetwork technologies such as WI-MAX, GSM, GPRS, 3G and others. TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  18. Wirelessswitchingtechnology Packet switching is the basic type of technology Uses short bursts of information, wireless switching uses channels only forshortperiods of time. protocols. Standard routing TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  19. Recall: Packet switching 2nd From W.Stallings,WirelessCommunicationsandNetworks, Edition TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  20. Recall: Packet switching (Contd..) FromW.Stallings,WirelessCommunicationsandNetworks, 2ndEdition TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  21. Wireless switching technology (Contd..) - Packets are routedandpipelinedusingmultiplexing - Bandwidthis used onlywhendata is transmitted TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  22. Wireless switching technology (Contd..) Virtual circuit Switched virtual circuits (SVCs) Established dynamically on demand 3 phases – circuit establishment, termination data transfer, circuit Permanentvirtualcircuits (PVCs) transfer Only one mode i.e., data TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  23. Wireless communication Increased bit error rate Lower transmission power Scattering Reflection Diffraction problems Multipath propagation Path loss TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  24. Wireless communication problems Increased bit error rate Wireless network media is more prone to obstacles between Tx and Rx Interference from neighbour nodes One can observe errors due to Frequentdisconnectionscausingto data loss Annoying to voice and video clients TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  25. Wireless communication problems (Contd..) Lower transmission power Mobile units powered by battery have scarce energy resources Limited transmission power to avoid interference Attenuation Capture power at the receiver side is Pr = Pt / (4 πd / l)2 Where Pt is the transmitter power, d the distance between and the receiver, and l is the wavelength of the signal. Lp = (4 πd / l)2 is the path loss. Scattering thetransmitter Occurs when signal pass through the object whose dimension is smallerthanthe wavelength. Scattered waves are produced by rough surfaces, small objects, irregularities in the channel. Need reduce it. properdeploymentstrategiesto TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  26. Wireless communication problems (Contd..) Reflection Occurs when electromagnetic wave strikes an object which has very large dimension compared to the wave length. Ex: walls, furniture, buildings, etc. Diffraction Occurs when radio path between Tx and Rx is obstructed by surfaces that will havesharpirregularities(edges)causingsecondary waves, which be present in space and behind the obstacle. TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  27. Wireless communication problems (Contd..) Multipath Propagation Caused by reflection and scattering Radio waves arrive at the Rx from different delays Final signal is the summation of all signals directionswithvarying Antennadiversitymethods are used to overcome this problem TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  28. Wirelessnetworkreferencemodel The OSI TCP/IParchitecture is functionally equivalent to the reference model. TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  29. Recall: TCP/IP Concepts 2nd From W.Stallings,WirelessCommunicationsandNetworks, Edition TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  30. Protocol Data Units in the TCP/IP Architecture Examples: TCP header includes destination port, sequence number, checksum IP header includes destination host address (B in previous example) Network header includes destination subnetwork address From W. Stallings, Wireless Communications and Networks, 2nd Edition TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  31. Wireless network reference model (Contd..) Major similarities and differences between TCP/IPand the OSI referencemodelsare Both models have an application, a transport, and a network/Internet layer The TCP/IP model does not have a session layer Lower layers connects the upper layers to the actual physicalnetwork TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  32. Wireless network reference model (Contd..) Application layer functions This is the layer where end user applications such as remote login, mail transfer, file transfer, network management, and web browsers run Transportlayer functions Its job is to provide reliable communication from application to application (end-to-end) regardless of communication links It encapsulates application layer data layer thelower-layerprotocolsand anddeliverittothenetwork TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  33. Illustration of the transport service TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  34. Wireless network reference model (Contd..) Data link layer functions This includes the logical link control (LLC) sublayer and MAC (media access control) sublayer. the It does segmenting the bit stream into frames, error handling, flow control, and access control. MAC is channel responsible and reliable for accessing and sharing of the wireless delivery by using acknowledgments. TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  35. Illustration ofdata link layer ComputerB ComputerA P P Bridge LLC P LLC P LLC P 802.4 LLC P 802.3LLC P 802.3 LLC P 8024 LLC P 802.4LLC P 802.3LLC P 802.3 LLC P 802 802.4 LLC P 802.3 LLC P 802 802.4LLC P TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

  36. Wireless network reference model (Contd..) Physical layer functions This layer transports encapsulated data from the data link transmits it wirelessly to the distant network. layer and Thewirelessfeaturesandfunctionality (modulation type, datarate, and so on) take place at this layer. TheseslidesarebasedontheslidesformattedbyDrSunilkumarS.manviandDr MahabaleshwarS. Kakkasageri,the authorsofthetextbook:WirelessandMobileNetworks, conceptsandprotocols.Seeslidenumberone.

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