Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar1 ECSE-4730: Computer Communication Networks (CCN) Chapter 5: The Data Link.

Slides:



Advertisements
Similar presentations
Networks: Wireless LANs1 Wireless Local Area Networks.
Advertisements

Comp 361, Spring 20056:Basic Wireless 1 Chapter 6: Basic Wireless (last updated 02/05/05) r A quick intro to CDMA r Basic
5: Link Layer and Local Area Networks5c-1 Hubs, Bridges, and Switches r Used for extending LANs in terms of geographical coverage, number of nodes, administration.
Chapter 6 High-Speed LANs1 Chapter 6 High-Speed LANs.
6: Wireless and Mobile Networks6-1 Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We’re making these slides freely available.
Overview r Ethernet r Hubs, bridges, and switches r Wireless links and LANs.
Network Technology CSE Network Technology CSE3020 Week 9.
Slow Start Backoff Algorithm for Wireless Ad Hoc Networks Der-Jiunn Deng Department of Computer Science and Information Engineering National Changhua University.
1 CSE401n:Computer Networks Lecture 16 Wireless Link & LANs WS: ch-14 KR: 5.7.
Wireless Networking So we talked about wired networks. What about wireless?
Wireless Local Area Networks
20 – Collision Avoidance, : Wireless and Mobile Networks6-1.
Lecture 3#1#1 Hubs, Bridges and Switches Lecture 3.
Wireless Security. Access Networks Core Networks The Current Internet: Connectivity and Processing Transit Net Private Peering NAP Public Peering PSTN.
1 Introduction to Wireless Networks Michalis Faloutsos.
6: Wireless and Mobile Networks6-1 Chapter 6: Wireless and Mobile Networks Background: r # wireless (mobile) phone subscribers now exceeds # wired phone.
1 Elements of a wireless network network infrastructure wireless hosts r laptop, PDA, IP phone r run applications r may be stationary (non- mobile) or.
Lecture 3#1#1 LAN Technologies Completing Lecture 2.
6/2/05CS118/Spring051 Chapter 6: Wireless and Mobile Networks r Cover the following sections only:  6.3: wireless LANs  6.5: mobility management:
5-1 Data Link Layer r Wireless Networks m Wi-Fi (Wireless LAN) Example Problems m RTS/CTS.
5-1 Data Link Layer r What is Data Link Layer? r Wireless Networks m Wi-Fi (Wireless LAN) r Comparison with Ethernet.
LAN Technologies. LAN technologies Data link layer so far: –services, error detection/correction, multiple access Next: LAN technologies –addressing –Ethernet.
8/7/20151 Mobile Computing COE 446 Wireless Multiple Access Tarek Sheltami KFUPM CCSE COE hthttp://faculty.kfupm.edu.sa/coe/tarek/coe446.htm Principles.
6: Wireless and Mobile Networks6-1 Elements of a wireless network network infrastructure wireless hosts r laptop, PDA, IP phone r run applications r may.
Chapter 6 Wireless and Mobile Networks Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 A note on.
Chapter 6 Wireless and Mobile Networks Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Wireless,
6: Wireless and Mobile Networks6-1 Chapter 6 Wireless and Mobile Networks Computer Networking: A Top Down Approach Featuring the Internet, 3 rd edition.
6: Wireless and Mobile Networks6-1 Chapter 6 Wireless and Mobile Networks Computer Networking: A Top Down Approach Featuring the Internet, 3 rd edition.
Adapted from: Computer Networking, Kurose/Ross 1DT066 Distributed Information Systems Chapter 6 Wireless, WiFi and mobility.
Chapter 5 outline 5.1 Introduction and services
ECE 4450:427/527 - Computer Networks Spring 2015
Wi-Fi Wireless LANs Dr. Adil Yousif. What is a Wireless LAN  A wireless local area network(LAN) is a flexible data communications system implemented.
CS 640: Introduction to Computer Networks Aditya Akella Lecture 23 - CSMA/CA, Ad Hoc and Sensor Networks.
5: DataLink Layer5a-1 Chapter 5 Data Link Layer Computer Networking: A Top Down Approach Featuring the Internet, 2 nd edition. Jim Kurose, Keith Ross Addison-Wesley,
Hubs, Bridges, and Switches (oh my) r Used for extending LANs in terms of geographical coverage, number of nodes, administration capabilities, etc. r Differ.
Wireless LAN Simulation - IEEE MAC Protocol
CS640: Introduction to Computer Networks Aditya Akella Lecture 22 - Wireless Networking.
Lecture #2 Chapter 14 Wireless LANs.
Overview of Wireless LANs Use wireless transmission medium Issues of high prices, low data rates, occupational safety concerns, & licensing requirements.
Computer Networking Bridges/Switches, , PPP.
CS640: Introduction to Computer Networks Aditya Akella Lecture 22 - Wireless Networking.
Chapter 5: The Data Link Layer
Wireless Access avoid collisions: 2 + nodes transmitting at same time CSMA - sense before transmitting –don’t collide with ongoing transmission by other.
K. Salah 1 Chapter 15 Wireless LANs. K. Salah 2 Figure 15.1 BSSs IEEE Specification for Wireless LAN: IEEE , which covers the physical and data.
IEEE Wireless LAN Standard. Medium Access Control-CSMA/CA IEEE defines two MAC sublayers Distributed coordination function (DCF) Point coordination.
CMPT771 Wireless Media 1 Wireless Basics CMPT 771 Internet Architecture and Protocols.
Wireless and Mobility The term wireless is normally used to refer to any type of electrical or electronic operation which is accomplished without the use.
Final Exam Wednesday 3/18/2015 Tech LR PM 1.
5: DataLink Layer5c-1 Today r Assign Homework m Ch5 #1,4,5,7,11,12 Due Wednesday October 22 m Ch5 #13-16,18,20 Due Monday, October 27 r Project #2 due.
Chapter 6 Medium Access Control Protocols and Local Area Networks Wireless LAN.
Ch 14. Wireless LANs IEEE Specification for a wireless LAN – Cover physical and data link layers Basic service sets (BSS) and extended service.
Universität Karlsruhe Institut für Telematik ECE 591
Lecture 27 University of Nevada – Reno Computer Science & Engineering Department Fall 2015 CPE 400 / 600 Computer Communication Networks Prof. Shamik Sengupta.
EEC-484/584 Computer Networks Lecture 14 Wenbing Zhao
Chapter 14 Wireless LANs.
Wireless Protocols. 2 Outline MACA 3 ISM: Industry, Science, Medicine unlicensed frequency spectrum: 900Mhz, 2.4Ghz, 5.1Ghz, 5.7Ghz.
MAC Layer Protocols for Wireless Networks. What is MAC? MAC stands for Media Access Control. A MAC layer protocol is the protocol that controls access.
1 Chapter 4 MAC Layer – Wireless LAN Jonathan C.L. Liu, Ph.D. Department of Computer, Information Science and Engineering (CISE), University of Florida.
Lecture 3 #1#1 Hubs, Bridges and Switches Lecture 3.
Getting Connected (Chapter 2 Part 4)
Computer Communication Networks
CS 457 – Lecture 7 Wireless Networks
Computer Communication & Networks
IEEE Wireless LAN wireless LANs: untethered (often mobile) networking
컴퓨터 네트워크 Chapter 4 컴퓨터 네트워크.
EEC-484/584 Computer Networks
Chapter 6 Medium Access Control Protocols and Local Area Networks
Introduction to Wireless Networks
EEC-484/584 Computer Networks
ECSE-4730: Computer Communication Networks (CCN)
Presentation transcript:

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar1 ECSE-4730: Computer Communication Networks (CCN) Chapter 5: The Data Link Layer - 3 Shivkumar Kalyanaraman: Biplab Sikdar: Chapter 5: The Data Link Layer - 3 Shivkumar Kalyanaraman: Biplab Sikdar:

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar2 Ethernet Switches - 1 layer 2 (frame) forwarding, filtering using LAN addresses Switching: A-to-B and A’- to-B’ simultaneously, no collisions large number of interfaces often: individual hosts, star-connected into switch Ethernet, but no collisions!

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar3 Ethernet Switches - 2 cut-through switching: frame forwarded from input to output port without awaiting for assembly of entire frame slight reduction in latency combinations of shared/dedicated, 10/100/1000 Mbps interfaces

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar4 Ethernet Switches - 3

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar5 IEEE Wireless LAN - 1 Wireless LANs: untethered (often mobile) networking IEEE standard: MAC protocol unlicensed frequency spectrum: 900Mhz, 2.4Ghz

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar6 Basic Service Set (BSS) (a.k.a. “cell”) contains: wireless hosts access point (AP): base station BSS’s combined to form distribution system (DS) IEEE Wireless LAN - 2

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar7 Ad Hoc Networks Ad hoc network: IEEE stations can dynamically form network without AP Applications: “laptop” meeting in conference room, car interconnection of “personal” devices battlefield IETF MANET (Mobile Ad hoc Networks) working group

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar8 IEEE MAC Protocol: CSMA/CA CSMA sender: - if sense channel idle for DISF sec. then transmit entire frame (no collision detection) -if sense channel busy then binary backoff CSMA receiver: if received OK return ACK after SIFS

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar9 IEEE MAC Protocol CSMA Protocol: others NAV: Network Allocation Vector frame has transmission time field others (hearing sata) defer access for NAV time units

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar10 Hidden Terminal effect hidden terminals: A, C cannot hear each other obstacles, signal attenuation collisions at B goal: avoid collisions at B CSMA/CA: CSMA with Collision Avoidance

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar11 Collision Avoidance: RTS-CTS exchange - 1 CSMA/CA: explicit channel reservation sender: send short RTS: request to send receiver: reply with short CTS: clear to send CTS reserves channel for sender, notifying (possibly hidden) stations Avoid hidden station collisions

Rensselaer Polytechnic Institute © Shivkumar Kalvanaraman & © Biplab Sikdar12 Collision Avoidance: RTS-CTS exchange - 2 RTS and CTS short: collisions less likely, of shorter duration end result similar to collision detection IEEE allows: CSMA CSMA/CA: reservations polling from AP