Ch 14. Wireless LANs. 14.1 IEEE 802.11 Specification for a wireless LAN – Cover physical and data link layers Basic service sets (BSS) and extended service.

Slides:

Advertisements

Similar presentations

Chapter 14 무선 LAN (Wireless LAN).

Advertisements

14.1 Chapter 14 Wireless LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Networks: Wireless LANs1 Wireless Local Area Networks.

© Kemal AkkayaWireless & Network Security 1 Department of Computer Science Southern Illinois University Carbondale CS591 – Wireless & Network Security.

Comp 361, Spring 20056:Basic Wireless 1 Chapter 6: Basic Wireless (last updated 02/05/05) r A quick intro to CDMA r Basic

14.1 Chapter 14 Wireless LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Network Technology CSE Network Technology CSE3020 Week 9.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Chapter 15 Wireless LANs.

1 CSE401n:Computer Networks Lecture 16 Wireless Link & LANs WS: ch-14 KR: 5.7.

CS541 Advanced Networking 1 Basics of Wireless Networking Neil Tang 1/21/2009.

Wireless Networking So we talked about wired networks. What about wireless?

Wireless Networks.

Networks: Wireless LANs1 Wireless Local Area Networks.

Wireless Local Area Networks

20 – Collision Avoidance, : Wireless and Mobile Networks6-1.

Networks: Wireless LANs1 Wireless Local Area Networks.

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

5-1 Data Link Layer r What is Data Link Layer? r Wireless Networks m Wi-Fi (Wireless LAN) r Comparison with Ethernet.

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.

Network Security Wireless LAN. Network Security About WLAN  IEEE standard  Use wireless transmission medium such as radio, microwave, infrared.

Wireless LANs Ethernet and all its enhancements is the major wired LAN architecture today Beyond Ethernet, the fastest growing LAN architecture is wireless.

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.

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.

1 Kyung Hee University Chapter 15 Wireless LANs. 2 Kyung Hee University IEEE 802 Standards Working Groups WiMAX, an acronym that stands for Worldwide.

IEEE Project started by IEEE for setting standard for LAN. This project started in (1980, February), Name given to project is year and month.

14.1 Chapter 14 Wireless LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

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.

Chapter 15 Wireless LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

IEEE Wireless LAN Standard. Medium Access Control-CSMA/CA IEEE defines two MAC sublayers Distributed coordination function (DCF) Point coordination.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Chapter 15 Wireless LANs.

F ACULTY OF C OMPUTER S CIENCE & E NGINEERING Chapter 05. MAC and Physical Layers.

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.

CSC 581 Communication Networks II Chapter 6c: Local Area Network (Wireless LAN – ) Dr. Cheer-Sun Yang.

Wireless LANs and PANs : Data Communication and Computer Networks Asst. Prof. Chaiporn Jaikaeo, Ph.D.

Chapter 6 Medium Access Control Protocols and Local Area Networks Wireless LAN.

WLAN. Networks: Wireless LANs2 Distribute Coordination Function (DCF) Distributed access protocol Contention-Based Uses CSMA/ CA – Uses both physical.

Chapter 15 Wireless LANs 15.# 1

14.1 Chapter 14 Wireless LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chapter 14 무선 LAN (Wireless LAN).

Chapter 13 Wired LANs: Ethernet

Chapter 14 Wireless LANs.

MAC Sublayer MAC layer tasks: – Control medium access – Roaming, authentication, power conservation Traffic services – DCF (Distributed Coordination.

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.

Copyright © 2003 OPNET Technologies, Inc. Confidential, not for distribution to third parties. Wireless LANs Session

IEEE Wireless LAN. Wireless LANs: Characteristics Types –Infrastructure based –Ad-hoc Advantages –Flexible deployment –Minimal wiring difficulties.

CS440 Computer Networks 1 Wireless LAN (IEEE ) Neil Tang 10/01/2008.

Wireless LAN Protocols This talk is based on the course: CPSC Networks and Distributed Processing Spring2006/

Wireless LAN Protocols This talk is based on the course: CPSC Networks and Distributed Processing Spring2006/

SSN College of Engineering

Chapter 15 Wireless LANs.

Computer Communication Networks

Chapter 3 Wireless LANs This work is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License. To view a copy of this.

Wireless NETWORKS NET 434 Topic No 7 Bluetooth-IEEE802.15

Wireless NETWORKS NET 434 Topic No 7 Bluetooth-IEEE802.15

Computer Communication & Networks

IEEE Wireless LAN wireless LANs: untethered (often mobile) networking

Wireless NETWORKS NET 434 Topic No 7 Bluetooth-IEEE802.15

Chapter 14 Wireless LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chapter 6 Medium Access Control Protocols and Local Area Networks

Wireless LAN (WLAN) Wireless Ethernet Bluetooth.

ECSE-4730: Computer Communication Networks (CCN)

Introduction Wireless communication is one of the fastest-growing technologies The demand for connecting devices without the use of cables is increasing.

Chapter 15 Wireless LANs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

IEEE Wireless Local Area Networks (RF-LANs)

Presentation transcript:

Ch 14. Wireless LANs

14.1 IEEE Specification for a wireless LAN – Cover physical and data link layers Basic service sets (BSS) and extended service set (ESS) BSS ESS

MAC Sublayer Architecture MAC in IEEE standard

Distributed Coordination Function (DCF) CSMA/CA – why not CSMA/CD? – A wireless station may not send data and receive collision signals at the same time – Collision may not be detected due to the hidden station problem (will discuss later) – Signal fading prevents a station of one end from hearing a collision at the other end Control frames – Request-To-Send (RTS): sent by the sender when it wants send a frame – Clear-To-Send (CTS): sent by the receiver when it receives an RTS and can receive the data

RTS/CTS Exchanges of DCF Network Allocation Vector (NAV) – RTS/CTS includes the duration of data transmission time – Stations affected by the transmission create a NAV timer to wait the end of the transmission

PCF Point coordination function (PCF) – Centralized, contention-free “polling” access – Use a shorter inter-frame space (PIFS) – Useful for time-sensitive service

Frame Format (RTS, CTS, ACK) Transmission type for addressing (See Fig. 14.9) Duration Sequence number of the frame

Transmission Type for Addressing

Control Frames RTS/CTS and ACK

Hidden Station Problem Station C cannot hear the transmission of station B (to A), and vice versa

Hidden Station Problem Solved by RTS/CTS exchange

Exposed Station Problem Station C can send to station D, but it is exposed to the transmission of station A (to B)

Exposed Station Problem Cannot solved by RTS/CTS exchange Normally, C does not transmit an RTS here. The figure shows that even if C transmits an RTS, it does not solve the problem

Physical Layers

14.2 Bluetooth Bluetooth: a wireless LAN technology designed to connect devices of different functions such as telephones, notebooks, computers, cameras, printers, coffee makers, and so on – Ad hoc network Piconet and scatternet

Bluetooth Layers (1) Radio layer – 10m range – 1 Mbps data rate – 2.4GHz ISM band, FHSS, GFSK modulation

Bluetooth Layers (2) Baseband layer (MAC) – TDD-TDMA (Time Division Duplex TDMA) – Single-Secondary Communication – Multiple-Secondary Communication Time for frequency hopping control

Homework Exercise in Chapter 14 – 11 – 12