Mobile devices for wireless

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Mobile devices for wireless"

Transcription

1 Mobile devices for wireless Wireless sensors Limited proc. power Small battery Laptop functionally eq. to desktop standard applications TDTS04/09 Föreläsning 0/6: WLAN och TCP i trådlösa nät RFID tag A few thousands of logical gates Responds only to the RFID reader requests (no battery) Pager receive only tiny displays simple text messages Mobile phones voice, data simple text displays PDA simple graphical displays character recognition simplified WWW performance Slides are modified from J.F Kurose and K.W. Ross Wireless systems: development over last 25 years What is missing? 98: NMT : NMT 900 cellular phones 992: GSM analogue digital 994: DCS : CDMA 2000: GPRS 983: AMPS 99: D-AMPS 993: PDC 200: UMTS/IMT-2000 CDMA-2000 (USA) 4G fourth generation - and IEEE 802.n; WiMax... satellites 982: Inmarsat-A 988: Inmarsat-C 992: Inmarsat-B Inmarsat-M 998: Iridium cordless phones 980: CT0 984: CT 987: CT+ 989: CT : Fourth Generation (Internet based) wireless LAN 99: DECT 99x: proprietary 997: IEEE : 802.b; Bluetooth 2000: IEEE 802.a Communication Frequency Spectrum Electromagnetic spectrum and applications (Tanenbaum 2003) NMT: Nordic Mobile Telephone AMPS: Advanced Mobile Phone System (USA) CT: Cordless Telephone UMTS: Universal Mobile Telecom. System DECT: Digital Enhanced Cordless Telecom. DCS: Digital Cellular System PDC: Pacific Digital Cellular PAN: Personal Area Network 6-3

2 Elements of a wireless network Elements of a wireless network network wireless hosts laptop, PDA, IP phone run applications may be stationary (non-mobile) or mobile wireless does not always mean mobility network base station typically connected to wired network relay - responsible for sending packets between wired network and wireless host(s) in its area e.g., cell towers, 802. access points Elements of a wireless network network wireless link typically used to connect mobile(s) to base station also used as backbone link multiple access protocol coordinates link access various data rates, transmission distance Data rate (Mbps) Characteristics of selected wireless link standards n a,g 802.b 802.a,g point-to-point IS-95, CDMA, GSM (WiMAX) UMTS/WCDMA-HSPDA, CDMA2000-xEVDO UMTS/WCDMA, CDMA2000 data 3G cellular enhanced 3G 2G Indoor 0-30m Outdoor m Mid-range outdoor 200m 4 Km Long-range outdoor 5Km 20 Km

3 Elements of a wireless network Elements of a wireless network network mode base station connects mobiles into wired network handoff: mobile changes base station providing connection into wired network ad hoc mode no base stations nodes can only transmit to other nodes within link coverage nodes organize themselves into a network: route among themselves Wireless network taxonomy Wireless Link Characteristics () single hop multiple hops Differences from wired link. (e.g., APs) no host connects to base station (WiFi, WiMAX, cellular) which connects to larger Internet no base station, no connection to larger Internet (Bluetooth, ad hoc nets) host may have to relay through several wireless nodes to connect to larger Internet: mesh net no base station, no connection to larger Internet. May have to relay to reach other a given wireless node MANET, VANET decreased signal strength: radio signal attenuates as it propagates through matter (path loss) interference from other sources: standardized wireless network frequencies (e.g., 2.4 GHz) shared by other devices (e.g., phone); devices (motors) interfere as well multipath propagation: radio signal reflects off objects ground, arriving ad destination at slightly different times. make communication across (even a point to point) wireless link much more difficult

4 Wireless Link Characteristics (2) SNR: signal-to-noise ratio larger SNR easier to extract signal from noise (a good thing ) SNR versus BER tradeoffs given physical layer: increase power -> increase SNR->decrease BER given SNR: choose physical layer that meets BER requirement, giving highest throughput SNR may change with mobility: dynamically adapt physical layer (modulation technique, rate) BER SNR(dB) QAM256 (8 Mbps) QAM6 (4 Mbps) BPSK ( Mbps) 6-3 Wireless network characteristics Multiple wireless senders and receivers create additional problems (beyond multiple access): A Hidden terminal problem B, A hear each other B, C hear each other A, C can not hear each other means A, C unaware of their interference at B C B A B C A s signal strength space C s signal strength Signal attenuation: B, A hear each other B, C hear each other A, C can not hear each other interfering at B 6-4 Stallings (2005), Wireless communications & Networks. 2nd Ed. Prentice Hall. IEEE 802. Standards 802. Physical Layer: Spread Spectrum Example, 802.b s DSSS (Direct Sequence Spread Spectrum) for each bit, send XOR of that bit and n random bits random sequence known to both sender and receiver called n-bit chipping code IEEE 802. defines an -bit chipping code. Data stream: 00 Random sequence: XOR of the two:

5 IEEE 802. Architecture Station: a device containing 802. equipment Basic Service Set (BSS): set of stations controlled by a coordination function Coordination function: logical function determining when a station can receive and send data in a BSS Distribution System (DS): a system connecting a set of BSS and integrated LANs to create an extended service set (ESS) Extended Service Set: a set of BSS and LANs appearing as a single unit to the LLC layer of the component stations Access point (AP) : entity providing access to the distribution system Figure from Stallings (2005), Wireless communications & Networks. 2nd Ed. Prentice Hall. IEEE 802. Services Figure from Stallings (2005), Wireless communications & Networks. 2nd Ed. Prentice Hall. 802.: Channels, association 802.: passive/active scanning 802.b: 2.4GHz-2.485GHz spectrum divided into channels at different frequencies AP admin chooses frequency for AP interference possible: channel can be same as that chosen by neighboring AP! host: must associate with an AP scans channels, listening for beacon frames containing AP s name (SSID) and MAC selects AP to associate with may perform authentication will typically run DHCP to get IP in AP s subnet AP BBS H BBS AP 2 Passive Scanning: () beacon frames sent from APs (2) association Request frame sent: H to selected AP (3) association Response frame sent: H to selected AP AP BBS 2 H BBS AP 2 Active Scanning: () Probe Request frame broadcast from H (2) Probes response frame sent from APs (3) Association Request frame sent: H to selected AP (4) Association Response frame sent: H to selected AP

6 IEEE 802.: multiple access IEEE 802. MAC Protocol: CSMA/CA avoid collisions: 2 + nodes transmitting at same time 802.: CSMA - sense before transmitting don t collide with ongoing transmission by other node 802.: no collision detection! difficult to receive (sense collisions) when transmitting due to weak received signals (fading) can t sense all collisions in any case: hidden terminal, fading goal: avoid collisions: CSMA/C(ollision)A(voidance) A C B A B C A s signal strength space C s signal strength sender if sense channel idle for DIFS then transmit entire frame (no CD) 2 if sense channel busy then start random backoff time timer counts down while channel idle transmit when timer expires if no ACK, increase random backoff interval, repeat receiver - if frame received OK return ACK after SIFS (ACK needed due to hidden terminal problem) DIFS sender data ACK receiver SIFS 6-22 IEEE 802. MAC: Priority-based scheme Use 3 values for IFS (Inter-Frame Space): SIFS (short IFS): shortest IFS used for immediate responses such as ACK, CTS, poll response PIFS (point coordination function IFS): middle length IFS used for issuing polls by a centralized controller DIFS (distributed coordination function IFS): longest IFS used for regular asynchronous frames Avoiding collisions idea: allow sender to reserve channel rather than random access of data frames: avoid collisions of long data frames sender first transmits small request-to-send (RTS) packets to BS using CSMA RTSs may still collide with each other (but they re short) BS broadcasts clear-to-send CTS in response to RTS RTS heard by all nodes sender transmits data frame other stations defer transmissions avoid data frame collisions completely using small reservation packets! Figure from Stallings (2005), Wireless communications & Networks. 2nd Ed. Prentice Hall

7 Collision Avoidance: RTS-CTS exchange 802. frame: ing A AP B reservation collision frame control duration 2 3 seq control 4 payload CRC time DATA (A) defer Address : MAC of wireless host or AP to receive this frame Address 2: MAC of wireless host or AP transmitting this frame Address 3: MAC of router interface to which AP is attached Address 4: used only when the DS is wireless frame: ing 802. frame: more duration of reserved transmission time (RTS/CTS) frame seq # (for reliable ARQ) H AP R router Internet frame control duration 2 3 seq control 4 payload CRC R MAC addr AP MAC addr dest. source frame AP MAC addr H MAC addr R MAC addr frame Protocol version Type Subtype To AP From AP frame type (RTS, CTS, ACK, data) More frag Power Retry mgt More data WEP Rsvd

8 IEEE 802. MAC Frame Types Six types of control frames Power save - poll (PS-poll) Request to send (RTS) Clear to send (CTS) Acknowledgment (ACK) Contention-free (CF)-end CF-end + CF-Ack Management frames association request and association response reassociation request and reassociation response probe request and probe response beacon announcement traffic indication message disassociation Eight types of data frames Carry user data Data Data + CF-Ack Data + CF-poll Data + CF-Ack + CF-poll Do not carry user data Null Function CF-Ack CF-Poll CF-Ack + CF-Poll 802.: mobility within same IP subnet Organizations extend WLAN with multiple BSSs H remains in same IP subnet: IP can remain same Problem w/switch: which AP is associated with H? authentication and deauthentication 6-30 BBS AP router hub or switch AP 2 H BBS : advanced capabilities 802.: advanced capabilities Rate Adaptation base station, mobile dynamically change transmission rate (physical layer modulation technique) as mobile moves, SNR varies QAM256 (8 Mbps) QAM6 (4 Mbps) BPSK ( Mbps) operating point BER SNR(dB). SNR decreases, BER increase as node moves away from base station 2. When BER becomes too high, switch to lower transmission rate but with lower BER Power Management node-to-ap: I am going to sleep until next beacon frame AP knows not to transmit frames to this node node wakes up before next beacon frame beacon frame: contains list of mobiles with APto-mobile frames waiting to be sent node will stay awake if AP-to-mobile frames to be sent; otherwise sleep again until next beacon frame

9 What is mobility? spectrum of mobility, from the network perspective: no mobility mobile wireless user, using same access point mobile user, connecting/ disconnecting from network using DHCP. high mobility mobile user, passing through multiple access point while maintaining ongoing connections (like cell phone) Wireless, mobility: impact on higher layer protocols logically, impact should be minimal best effort service model remains unchanged TCP and UDP can (and do) run over wireless, mobile but performance-wise: packet loss/delay due to bit-errors (discarded packets, delays for link-layer retransmissions), and handoff TCP interprets loss as congestion, will decrease congestion window un-necessarily delay impairments for real-time traffic limited bandwidth of wireless links TCP i trådlösa nät Snooping TCP a) Från fast nät till mobil station indirect (split) TCP snooping TCP TCP i radionät: trådlös profil 9

10 Snooping TCP, forts. b) Från mobil station till fast nät TCP:s trådlösa profil stora fönsterstorlekar (fönsterskalning) stor MTU selektiva ACKar explicit stockningsmeddelande (ECN) tidsstämpel TCP: Fönsterskalning Källa: Halsall (2005), Computer networking and the Internet. 5th Ed. Addison-Wesley. 0

Topic 2b Wireless MAC. Chapter 7. Wireless and Mobile Networks. Computer Networking: A Top Down Approach

Topic 2b Wireless MAC. Chapter 7. Wireless and Mobile Networks. Computer Networking: A Top Down Approach Topic 2b Wireless MAC Chapter 7 Wireless and Mobile Networks Computer Networking: A Top Down Approach 7 th edition Jim Kurose, Keith Ross Pearson/Addison Wesley April 2016 7-1 Ch. 7: Background: # wireless

More information

Wireless and Mobile Networks 7-2

Wireless and Mobile Networks 7-2 Wireless and Mobile Networks EECS3214 2018-03-26 7-1 Ch. 6: Wireless and Mobile Networks Background: # wireless (mobile) phone subscribers now exceeds # wired phone subscribers (5-to-1)! # wireless Internet-connected

More information

Wireless Networks. CSE 3461: Introduction to Computer Networking Reading: , Kurose and Ross

Wireless Networks. CSE 3461: Introduction to Computer Networking Reading: , Kurose and Ross Wireless Networks CSE 3461: Introduction to Computer Networking Reading: 6.1 6.3, Kurose and Ross 1 Wireless Networks Background: Number of wireless (mobile) phone subscribers now exceeds number of wired

More information

CSC 4900 Computer Networks: Wireless Networks

CSC 4900 Computer Networks: Wireless Networks CSC 4900 Computer Networks: Wireless Networks Professor Henry Carter Fall 2017 Last Time Mobile applications are taking off! What about current platforms is fueling this? How are an application s permission

More information

Mohammad Hossein Manshaei 1393

Mohammad Hossein Manshaei 1393 Mohammad Hossein Manshaei manshaei@gmail.com 1393 Wireless Links, WiFi, Cellular Internet Access, and Mobility Slides derived from those available on the Web site of the book Computer Networking, by Kurose

More information

6.9 Summary. 11/20/2013 Wireless and Mobile Networks (SSL) 6-1. Characteristics of selected wireless link standards a, g point-to-point

6.9 Summary. 11/20/2013 Wireless and Mobile Networks (SSL) 6-1. Characteristics of selected wireless link standards a, g point-to-point Chapter 6 outline 6.1 Introduction Wireless 6.2 Wireless links, characteristics CDMA 6.3 IEEE 802.11 wireless LANs ( wi-fi ) 6.4 Cellular Internet Access architecture standards (e.g., GSM) Mobility 6.5

More information

CS 332 Computer Networks Wireless Networks

CS 332 Computer Networks Wireless Networks CS 332 Computer Networks Wireless Networks Professor Szajda Chapter 6: Wireless and Mobile Networks Background: # wireless (mobile) phone subscribers now exceeds # wired phone subscribers! computer nets:

More information

Last Lecture: Data Link Layer

Last Lecture: Data Link Layer Last Lecture: Data Link Layer 1. Design goals and issues 2. (More on) Error Control and Detection 3. Multiple Access Control (MAC) 4. Ethernet, LAN Addresses and ARP 5. Hubs, Bridges, Switches 6. Wireless

More information

ECE 4450:427/527 - Computer Networks Spring 2017

ECE 4450:427/527 - Computer Networks Spring 2017 ECE 4450:427/527 - Computer Networks Spring 2017 Dr. Nghi Tran Department of Electrical & Computer Engineering Lecture 5.6: Wireless Networks - MAC Dr. Nghi Tran (ECE-University of Akron) ECE 4450:427/527

More information

CSCI-1680 Wireless Chen Avin

CSCI-1680 Wireless Chen Avin CSCI-1680 Wireless Chen Avin Based on slides from Computer Networking: A Top Down Approach - 6th edition Administrivia TCP is due on Friday Final Project is out (fun, two weeks) Wireless and Mobile Networks

More information

COMP 3331/9331: Computer Networks and Applications

COMP 3331/9331: Computer Networks and Applications COMP 3331/9331: Computer Networks and Applications Week 10 Wireless Networks Reading Guide: Chapter 6: 6.1 6.3 Wireless Networks + Security 1 Wireless and Mobile Networks Background: # wireless (mobile)

More information

Shared Access Networks Wireless. 1/27/14 CS mywireless 1

Shared Access Networks Wireless. 1/27/14 CS mywireless 1 Shared Access Networks Wireless 1 Wireless and Mobile Networks Background: # wireless (mobile) phone subscribers now exceeds # wired phone subscribers (5-to-1)! # wireless Internet-connected devices equals

More information

Data Communication & Networks G Session 5 - Main Theme Wireless Networks. Dr. Jean-Claude Franchitti

Data Communication & Networks G Session 5 - Main Theme Wireless Networks. Dr. Jean-Claude Franchitti Data Communication & Networks G22.2262-001 Session 5 - Main Theme Wireless Networks Dr. Jean-Claude Franchitti New York University Computer Science Department Courant Institute of Mathematical Sciences

More information

Chapter 6 Wireless and Mobile Networks

Chapter 6 Wireless and Mobile Networks Chapter 6 Wireless and Mobile Networks Computer Networking: A Top Down Approach Featuring the Internet, 3 rd edition. Jim Kurose, Keith Ross Addison-Wesley, July 2004. 6: Wireless and Mobile Networks 6

More information

Chapter 6 Wireless and Mobile Networks. Chapter 6 outline. Chapter 6: Wireless and Mobile Networks. Elements of a wireless network

Chapter 6 Wireless and Mobile Networks. Chapter 6 outline. Chapter 6: Wireless and Mobile Networks. Elements of a wireless network Chapter 6 Wireless and Mobile Networks Computer Networking: Top Down pproach 5 th edition. Jim Kurose, Keith Ross ddison-wesley, pril 009. Chapter 6: Wireless and Mobile Networks ackground: # wireless

More information

CPSC 826 Internetworking. Wireless and Mobile Networks. Wireless Networks Wireless Hosts

CPSC 826 Internetworking. Wireless and Mobile Networks. Wireless Networks Wireless Hosts 1 CPSC 826 Intering Wireless and Mobile Networks Michele Weigle Department of Computer Science Clemson University mweigle@cs.clemson.edu November 29, 200 Wireless and Mobile Networks Background Number

More information

Multiple Access in Cellular and Systems

Multiple Access in Cellular and Systems Multiple Access in Cellular and 802.11 Systems 1 GSM The total bandwidth is divided into many narrowband channels. (200 khz in GSM) Users are given time slots in a narrowband channel (8 users) A channel

More information

COMP 3331/9331: Computer Networks and Applications

COMP 3331/9331: Computer Networks and Applications COMP 3331/9331: Computer Networks and Applications Week 10 Reading Guide: Chapter 6: 6.1 6.4 1 Ch. 6: Wireless and Mobile Networks Background: v # wireless (mobile) phone subscribers now exceeds # wired

More information

Wireless and Mobile Networks

Wireless and Mobile Networks Wireless and Mobile Networks Raj Jain Washington University in Saint Louis Saint Louis, MO 63130 Jain@wustl.edu Audio/Video recordings of this lecture are available on-line at: http://www.cse.wustl.edu/~jain/cse473-11/

More information

CSC 8560 Computer Networks: Wireless and Mobility

CSC 8560 Computer Networks: Wireless and Mobility CSC 8560 Computer Networks: Wireless and Mobility Professor Henry Carter Fall 2017 Chapter 7: Wireless and Mobile Networks Background: # wireless (mobile) phone subscribers now exceeds # wired phone subscribers!

More information

Wireless Networks. CSE 3461: Introduction to Computer Networking Reading: , Kurose and Ross ( 6th ed.); , Kurose and Ross (7th ed.

Wireless Networks. CSE 3461: Introduction to Computer Networking Reading: , Kurose and Ross ( 6th ed.); , Kurose and Ross (7th ed. Wireless Networks CSE 3461: Introduction to Computer Networking Reading: 6.1 6.3, Kurose and Ross ( 6th ed.); 7.1 7.3, Kurose and Ross (7th ed.) 1 Questions How do you use wireless network technology in

More information

Home Area Networks. Outline

Home Area Networks. Outline Home Area Networks CS 687 University of Kentucky Fall 2015 Acknowledgment: Some slides are adapted from the slides distributed with the book Computer Networking: A Top Down Approach, 5th edition. Jim Kurose,

More information

Elements of a wireless network. Elements of a wireless network. Characteristics of selected wireless link standards. Elements of a wireless network

Elements of a wireless network. Elements of a wireless network. Characteristics of selected wireless link standards. Elements of a wireless network wireless hosts laptop, D, I phone run applications may be stationary (non-mobile) or mobile wireless does not always mean mobility base station typically connected to wired relay - responsible for sending

More information

Medium Access Control

Medium Access Control Medium Access Control All material copyright 1996-2009 J.F Kurose and K.W. Ross, All Rights Reserved 5: DataLink Layer 5-1 Link Layer Introduction and services Multiple access protocols Ethernet Wireless

More information

Chapter 6 Wireless and Mobile Networks. Chapter 6 outline. Chapter 6: Wireless and Mobile Networks. Elements of a wireless network.

Chapter 6 Wireless and Mobile Networks. Chapter 6 outline. Chapter 6: Wireless and Mobile Networks. Elements of a wireless network. Chapter 6 Wireless and obile Networks Computer Networking: A Top Down Approach Featuring the Internet, 3 rd edition. Jim Kurose, Keith Ross Addison-Wesley, July 2004. Chapter 6: Wireless and obile Networks

More information

Elements of a wireless network. Elements of a wireless network. Some wireless link standards. Elements of a wireless network

Elements of a wireless network. Elements of a wireless network. Some wireless link standards. Elements of a wireless network Elements of a wireless Elements of a wireless wireless hosts laptop, D, I phone run applications may be stationary (non-mobile) or mobile wireless does not always mean mobility base station typically connected

More information

Multiple Access Links and Protocols

Multiple Access Links and Protocols Multiple Access Links and Protocols Two types of links : point-to-point PPP for dial-up access point-to-point link between Ethernet switch and host broadcast (shared wire or medium) old-fashioned Ethernet

More information

Link Layer. 5.1 Introduction and services 5.2 Error detection and correction 5.3Multiple access protocols 5.4 Link-Layer Addressing 5.

Link Layer. 5.1 Introduction and services 5.2 Error detection and correction 5.3Multiple access protocols 5.4 Link-Layer Addressing 5. Link Layer 5.1 Introduction and services 5.2 Error detection and correction 5.3Multiple access protocols 5.4 Link-Layer Addressing 5.5 Ethernet 5.6 Link-layer switches 5.7 PPP 5.8 Link Virtualization:

More information

M06:Wireless and Mobile Networks. Corinna Schmitt

M06:Wireless and Mobile Networks. Corinna Schmitt M06:Wireless and Mobile Networks Corinna Schmitt corinna.schmitt@unibas.ch Acknowledgement 2016 M06 2 Background q # wireless (mobile) phone subscribers now exceeds # wired phone subscribers (5-to-1)!

More information

Chapter 6 Wireless and Mobile Networks

Chapter 6 Wireless and Mobile Networks Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations;

More information

Mobile and Sensor Systems

Mobile and Sensor Systems Mobile and Sensor Systems Lecture 2: Mobile Medium Access Control Protocols and Wireless Systems Dr Cecilia Mascolo In this lecture We will describe medium access control protocols and wireless systems

More information

Chapter 6 Wireless and Mobile Networks

Chapter 6 Wireless and Mobile Networks Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations;

More information

Module 6: Wireless Mobile Networks

Module 6: Wireless Mobile Networks Module 6: Wireless Mobile Networks SMD123 Computer Communications Kaustubh Phanse Department of Computer Science and Electrical Engineering Luleå University of Technology Lecture Objectives Wireless links

More information

Wireless Internet Routing. Review of Wireless Networking (with Routing in Mind)

Wireless Internet Routing. Review of Wireless Networking (with Routing in Mind) Wireless Internet Routing Review of Wireless Networking (with Routing in Mind) 1 Review of Wireless Networking Architecture of wireless networks Wireless PHY Wireless MAC o 802.11 PHY: physical layer /

More information

Chapter 6 Wireless and Mobile Networks. Chapter 6 outline. Chapter 6: Wireless and Mobile Networks. Elements of a wireless network

Chapter 6 Wireless and Mobile Networks. Chapter 6 outline. Chapter 6: Wireless and Mobile Networks. Elements of a wireless network Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add,

More information

Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ

Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ Chapter 6 Wireless and Mobile Networks Computer Networking: A Top Down Approach, 5 th edition. Jim Kurose, Keith Ross Addison-Wesley,

More information

Chapter 6 Wireless and Mobile Networks

Chapter 6 Wireless and Mobile Networks Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add,

More information

Chapter 6 Wireless and Mobile Networks

Chapter 6 Wireless and Mobile Networks Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add,

More information

Chapter 7. Wireless and Mobile Networks. Computer Networking: A Top Down Approach. Andrei Gurtov

Chapter 7. Wireless and Mobile Networks. Computer Networking: A Top Down Approach. Andrei Gurtov Chapter 7 Wireless and Mobile Networks Andrei Gurtov All material copyright 1996-2016 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach 7 th edition Jim Kurose, Keith

More information

Chapter 7. Wireless and Mobile Networks. Computer Networking: A Top Down Approach

Chapter 7. Wireless and Mobile Networks. Computer Networking: A Top Down Approach Chapter 7 Wireless and Mobile Networks A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see

More information

Chapter 6 Wireless and Mobile Networks

Chapter 6 Wireless and Mobile Networks Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add,

More information

Chapter 5 Wireless and Mobile Networks

Chapter 5 Wireless and Mobile Networks Chapter 5 Wireless and Mobile Networks Reference: Computer Networking: A Top Down Approach 4 th edition. Jim Kurose, Keith Ross Addison-Wesley, July 2007. Wireless and Mobile Networks Chapter 5: Wireless

More information

Already finished all layers in the stack, why a separate chapter for wireless and mobile networks?

Already finished all layers in the stack, why a separate chapter for wireless and mobile networks? Wireless and Mobile Networks Yanmin Zhu Department of Computer Science and Engineering Mobile lobal ISP Home Regional ISP Institutional Already finished all layers in the stack, why a separate chapter

More information

Computer Networks. Wireless and Mobile Networks. László Böszörményi Computer Networks Mobile - 1

Computer Networks. Wireless and Mobile Networks. László Böszörményi Computer Networks Mobile - 1 Computer Networks Wireless and Mobile Networks László Böszörményi Computer Networks Mobile - 1 Background Number of wireless (mobile) phone subscribers now exceeds number of wired phone subscribers! Computer

More information

Wireless and Mobile Networks

Wireless and Mobile Networks Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add,

More information

Lecture 15 Wireless and Mobility

Lecture 15 Wireless and Mobility Lecture 15 Wireless and Mobility From Kurose & Ross Book slightly modified by Romaric Duvignau duvignau@chalmers.se Thanks and enjoy! JFK/KWR All material copyright 1996-2016 J.F Kurose and K.W. Ross,

More information

MULTIPLE ACCESS PROTOCOLS 2. 1

MULTIPLE ACCESS PROTOCOLS 2. 1 MULTIPLE ACCESS PROTOCOLS AND WIFI 1 MULTIPLE ACCESS PROTOCOLS 2. 1 MULTIPLE ACCESS LINKS, PROTOCOLS Two types of links : point-to-point broadcast (shared wire or medium) POINT-TO-POINT PPP for dial-up

More information

Wireless and WiFi. Daniel Zappala. CS 460 Computer Networking Brigham Young University

Wireless and WiFi. Daniel Zappala. CS 460 Computer Networking Brigham Young University Wireless and WiFi Daniel Zappala CS 460 Computer Networking Brigham Young University Wireless Networks 2/28 mobile phone subscribers now outnumber wired phone subscribers similar trend likely with Internet

More information

Chapter 7. Wireless and Mobile Networks. Computer Networking: A Top Down Approach

Chapter 7. Wireless and Mobile Networks. Computer Networking: A Top Down Approach Chapter 7 Wireless and Mobile Networks A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see

More information

Chapter 6 Wireless and Mobile Networks

Chapter 6 Wireless and Mobile Networks Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add,

More information

(Wireless) Internet Routing. Review of Wireless Networking (with Routing in Mind)

(Wireless) Internet Routing. Review of Wireless Networking (with Routing in Mind) (Wireless) Internet Routing Review of Wireless Networking (with Routing in Mind) 1 Review of Wireless Networking Architecture of wireless networks Wireless PHY Wireless MAC o 802.11 PHY: physical layer

More information

Chapter 6 Wireless and Mobile Networks

Chapter 6 Wireless and Mobile Networks Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add,

More information

Chapter 6 Wireless and Mobile Networks (Wireless and Mobility)

Chapter 6 Wireless and Mobile Networks (Wireless and Mobility) CSF645 Mobile Computing 行動計算 Chapter 6 Wireless and Mobile Networks (Wireless and Mobility) Computer Networking: A Top Down Approach 6 th edition, Jim Kurose, Keith Ross 吳俊興國立高雄大學資訊工程學系 outline 6.1 Introduction

More information

Wireless and Mobile Networks

Wireless and Mobile Networks Wireless and Mobile Networks Background: # wireless (mobile) phone subscribers now exceeds # wired phone subscribers (5-to-1)! # wireless Internet-connected devices equals # wireline Internet-connected

More information

Chapter 7. Wireless and Mobile Networks 7-1

Chapter 7. Wireless and Mobile Networks 7-1 Chapter 7 Wireless and Mobile Networks A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see

More information

Chapter 6 Wireless and Mobile Networks

Chapter 6 Wireless and Mobile Networks Chapter 6 Wireless and Mobile Networks A note on the use of these ppt slides: The notes used in this course are substantially based on powerpoint slides developed and copyrighted by J.F. Kurose and K.W.

More information

CSC 498R: Internet of Things 2

CSC 498R: Internet of Things 2 CSC 498R: Internet of Things Lecture 04: Wireless Networks Instructor: Haidar M. Harmanani IoT Components Things we connect: Hardware, sensors and actuators Connectivity Medium we use to connect things

More information

IEEE WLANs (WiFi) Part II/III System Overview and MAC Layer

IEEE WLANs (WiFi) Part II/III System Overview and MAC Layer IEEE 802.11 WLANs (WiFi) Part II/III System Overview and MAC Layer Design goals for wireless LANs (WLANs) Global, seamless operation Low power for battery use No special permissions or licenses needed

More information

CSCD 433 Network Programming Fall Lecture 7 Ethernet and Wireless

CSCD 433 Network Programming Fall Lecture 7 Ethernet and Wireless CSCD 433 Network Programming Fall 2016 Lecture 7 Ethernet and Wireless 802.11 1 Topics 802 Standard MAC and LLC Sublayers Review of MAC in Ethernet MAC in 802.11 Wireless 2 IEEE Standards In 1985, Computer

More information

Chapter 3: Wireless and Mobile Networks

Chapter 3: Wireless and Mobile Networks Computer Network Architectures and Multimedia Guy Leduc Chapter 3 Wireless and Mobile Networks Chapter 7 of Computer Networking: A Top Down Approach, 7 th edition. Jim Kurose, Keith Ross Addison-Wesley,

More information

3/20/2012. Data Communications & Networks. Session 5 Main Theme. 2 Wireless and Mobile Networks. Dr. Jean-Claude Franchitti

3/20/2012. Data Communications & Networks. Session 5 Main Theme. 2 Wireless and Mobile Networks. Dr. Jean-Claude Franchitti Data Communications & Networks Session 5 Main Theme Wireless and Mobile Networks Dr. Jean-Claude Franchitti New York University Computer Science Department Courant Institute of Mathematical Sciences Adapted

More information

Wireless and Mobile Networks Reading: Sections 2.8 and 4.2.5

Wireless and Mobile Networks Reading: Sections 2.8 and 4.2.5 Wireless and Mobile Networks Reading: Sections 2.8 and 4.2.5 Acknowledgments: Lecture slides are from Computer networks course thought by Jennifer Rexford at Princeton University. When slides are obtained

More information

Mohammad Hossein Manshaei 1393

Mohammad Hossein Manshaei 1393 Mohammad Hossein Manshaei manshaei@gmail.com 1393 1 802.11 History and Standardization 802.11 Architectures and Layers 802.11 Frame Format and Addressing 802.11 Mac Layer (CSMA/CA) 2 Wifi 3 twisted pair

More information

Data Communications. Data Link Layer Protocols Wireless LANs

Data Communications. Data Link Layer Protocols Wireless LANs Data Communications Data Link Layer Protocols Wireless LANs Wireless Networks Several different types of communications networks are using unguided media. These networks are generally referred to as wireless

More information

Announcements: ECE/CS 372 introduction to computer networks. Assignment 4 due now. Chapter 7

Announcements: ECE/CS 372 introduction to computer networks. Assignment 4 due now. Chapter 7 ECE/CS 372 introduction to computer networks Announcements: Assignment 4 due now Chapter 7 Acknowledgement: slides drawn heavily from Kurose & Ross and Prof. Bechir Hamdaoui Chapter 7, slide 1 Wireless

More information

standard. Acknowledgement: Slides borrowed from Richard Y. Yale

standard. Acknowledgement: Slides borrowed from Richard Y. Yale 802.11 standard Acknowledgement: Slides borrowed from Richard Y. Yang @ Yale IEEE 802.11 Requirements Design for small coverage (e.g. office, home) Low/no mobility High data rate applications Ability to

More information

Chapter 6 Medium Access Control Protocols and Local Area Networks

Chapter 6 Medium Access Control Protocols and Local Area Networks Chapter 6 Medium Access Control Protocols and Local Area Networks 802.11 Wireless LAN CSE 3213, Winter 2010 Instructor: Foroohar Foroozan Wireless Data Communications Wireless communications compelling

More information

Functions of physical layer:

Functions of physical layer: Chapter 14 Functions of physical layer: Encoding/decoding of signals Preamble generation/removal (for synchronization) Bit transmission/reception Includes specification of the transmission medium Functions

More information

Multiple Access Links and Protocols

Multiple Access Links and Protocols Multiple Access Links and Protocols Two types of links : point-to-point PPP for dial-up access point-to-point link between Ethernet switch and host broadcast (shared wire or medium) old-fashioned Ethernet

More information

Lecture 16: QoS and "

Lecture 16: QoS and Lecture 16: QoS and 802.11" CSE 123: Computer Networks Alex C. Snoeren HW 4 due now! Lecture 16 Overview" Network-wide QoS IntServ DifServ 802.11 Wireless CSMA/CA Hidden Terminals RTS/CTS CSE 123 Lecture

More information

Data and Computer Communications. Chapter 13 Wireless LANs

Data and Computer Communications. Chapter 13 Wireless LANs Data and Computer Communications Chapter 13 Wireless LANs Wireless LAN Topology Infrastructure LAN Connect to stations on wired LAN and in other cells May do automatic handoff Ad hoc LAN No hub Peer-to-peer

More information

Wireless Security Background

Wireless Security Background Wireless Security Background Wireless Networks The need for mobile computing Laptops, PDAs, Bluetooth devices Smart phones Enabling technology Wireless communication Two important characteristics Wireless

More information

04/11/2011. Wireless LANs. CSE 3213 Fall November Overview

04/11/2011. Wireless LANs. CSE 3213 Fall November Overview Wireless LANs CSE 3213 Fall 2011 4 November 2011 Overview 2 1 Infrastructure Wireless LAN 3 Applications of Wireless LANs Key application areas: LAN extension cross-building interconnect nomadic access

More information

Wireless Local Area Networks (WLANs)) and Wireless Sensor Networks (WSNs) Computer Networks: Wireless Networks 1

Wireless Local Area Networks (WLANs)) and Wireless Sensor Networks (WSNs) Computer Networks: Wireless Networks 1 Wireless Local Area Networks (WLANs)) and Wireless Sensor Networks (WSNs) Computer Networks: Wireless Networks 1 Wireless Local Area Networks The proliferation of laptop computers and other mobile devices

More information

Last time?! MPLS! Label distribution protocols! Multi Protocol Label Switching! Layer 2.5 protocol! LDP! RSVP!

Last time?! MPLS! Label distribution protocols! Multi Protocol Label Switching! Layer 2.5 protocol! LDP! RSVP! Part2: SDNs Last time? MPLS Multi Protocol Label Switching Layer 2.5 protocol Label distribution protocols LDP RSVP Per router control plane Individual routing algorithm components in each and every router

More information

Wireless Local Area Networks. Networks: Wireless LANs 1

Wireless Local Area Networks. Networks: Wireless LANs 1 Wireless Local Area Networks Networks: Wireless LANs 1 Wireless Local Area Networks The proliferation of laptop computers and other mobile devices (PDAs and cell phones) created an obvious application

More information

Wireless LANs. ITS 413 Internet Technologies and Applications

Wireless LANs. ITS 413 Internet Technologies and Applications Wireless LANs ITS 413 Internet Technologies and Applications Aim: Aim and Contents Understand how IEEE 802.11 wireless LANs work Understand what influences the performance of wireless LANs Contents: IEEE

More information

Mobile & Wireless Networking. Lecture 7: Wireless LAN

Mobile & Wireless Networking. Lecture 7: Wireless LAN 192620010 Mobile & Wireless Networking Lecture 7: Wireless LAN [Schiller, Section 7.3] [Reader, Part 6] [Optional: "IEEE 802.11n Development: History, Process, and Technology", Perahia, IEEE Communications

More information

MSIT 413: Wireless Technologies Week 8

MSIT 413: Wireless Technologies Week 8 MSIT 413: Wireless Technologies Week 8 Michael L. Honig Department of EECS Northwestern University November 2017 The Multiple Access Problem How can multiple mobiles access (communicate with) the same

More information

Wireless Local Area Networks (WLANs) and Wireless Sensor Networks (WSNs) Primer. Computer Networks: Wireless LANs

Wireless Local Area Networks (WLANs) and Wireless Sensor Networks (WSNs) Primer. Computer Networks: Wireless LANs Wireless Local Area Networks (WLANs) and Wireless Sensor Networks (WSNs) Primer 1 Wireless Local Area Networks (WLANs) The proliferation of laptop computers and other mobile devices (PDAs and cell phones)

More information

MAC in /20/06

MAC in /20/06 MAC in 802.11 2/20/06 MAC Multiple users share common medium. Important issues: Collision detection Delay Fairness Hidden terminals Synchronization Power management Roaming Use 802.11 as an example to

More information

Communication Networks: Wireless and Mobile Communication Networks. Prof. Amir Herzberg BIU, Dept. of CS

Communication Networks: Wireless and Mobile Communication Networks. Prof. Amir Herzberg BIU, Dept. of CS 89-850 Communication Networks: Wireless and Mobile Communication Networks Prof. Amir Herzberg BIU, Dept. of CS From ch.6 of Kurose and Ross, 3 rd edition; and [KMK], ch. 8. All material copyright 1996-2004

More information

Chapter 5 Link Layer and LANs

Chapter 5 Link Layer and LANs Chapter 5 Link Layer and LANs A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and

More information

Block 3: Lecture 1! Part 3: Lecture 1! Wireless networks!

Block 3: Lecture 1! Part 3: Lecture 1! Wireless networks! Block 3: Lecture 1 Part 3: Lecture 1 Wireless networks Part 3 Wireless and mobile networks: 1. Wireless technologies 2. Mobility 3. Fiber day on Friday May 22nd Long time ago... Marconi invented the wireless

More information

Computer Communication III

Computer Communication III Computer Communication III Wireless Media Access IEEE 802.11 Wireless LAN Advantages of Wireless LANs Using the license free ISM band at 2.4 GHz no complicated or expensive licenses necessary very cost

More information

Wireless Challenges : Computer Networking. Overview. Routing to Mobile Nodes. Lecture 25: Wireless Networking

Wireless Challenges : Computer Networking. Overview. Routing to Mobile Nodes. Lecture 25: Wireless Networking Wireless Challenges 15-441: Computer Networking Lecture 25: Wireless Networking Force us to rethink many assumptions Need to share airwaves rather than wire Don t know what hosts are involved Host may

More information

CSMC 417. Computer Networks Prof. Ashok K Agrawala Ashok Agrawala. Fall 2018 CMSC417 Set 1 1

CSMC 417. Computer Networks Prof. Ashok K Agrawala Ashok Agrawala. Fall 2018 CMSC417 Set 1 1 CSMC 417 Computer Networks Prof. Ashok K Agrawala 2018 Ashok Agrawala Fall 2018 CMSC417 Set 1 1 The Medium Access Control Sublayer November 18 Nov 6, 2018 2 Wireless Networking Technologies November 18

More information

Announcements: Assignment 4 due now Lab 4 due next Tuesday Assignment 5 posted, due next Thursday

Announcements: Assignment 4 due now Lab 4 due next Tuesday Assignment 5 posted, due next Thursday ECE/CS 372 introduction to computer networks Lecture 15 Announcements: Assignment 4 due now Lab 4 due next Tuesday Assignment 5 posted, due next Thursday Credit for lecture slides to Professor Bechir Hamdaoui

More information

Announcements: ECE/CS 372 introduction to computer networks. Assign 4 is due this Thursday Lab 4 is due next Tuesday Assignment 5 posted soon

Announcements: ECE/CS 372 introduction to computer networks. Assign 4 is due this Thursday Lab 4 is due next Tuesday Assignment 5 posted soon ECE/CS 372 introduction to computer networks Lecture 14 Announcements: Assign 4 is due this Thursday Lab 4 is due next Tuesday Assignment 5 posted soon Credit for lecture slides to Professor Bechir Hamdaoui

More information

Wireless Communication and Networking CMPT 371

Wireless Communication and Networking CMPT 371 Wireless Communication and Networking CMPT 371 Wireless Systems: AM, FM Radio TV Broadcast Satellite Broadcast 2-way Radios Cordless Phones Satellite Links Mobile Telephony Systems Wireless Local Loop

More information

Mobile Communications Chapter 7: Wireless LANs

Mobile Communications Chapter 7: Wireless LANs Characteristics IEEE 802.11 PHY MAC Roaming IEEE 802.11a, b, g, e HIPERLAN Bluetooth Comparisons Prof. Dr.-Ing. Jochen Schiller, http://www.jochenschiller.de/ MC SS02 7.1 Comparison: infrastructure vs.

More information

Chapter 7. Wireless and Mobile Networks. Computer Networking: A Top Down Approach

Chapter 7. Wireless and Mobile Networks. Computer Networking: A Top Down Approach Chapter 7 Wireless and Mobile Networks Computer Networking: A Top Down Approach 7 th edition Jim Kurose, Keith Ross Pearson/Addison Wesley April 2016 7-1 Background: # wireless (mobile) phone subscribers

More information

CS118 Discussion 1A, Week 9. Zengwen Yuan Dodd Hall 78, Friday 10:00 11:50 a.m.

CS118 Discussion 1A, Week 9. Zengwen Yuan Dodd Hall 78, Friday 10:00 11:50 a.m. CS118 Discussion 1A, Week 9 Zengwen Yuan Dodd Hall 78, Friday 10:00 11:50 a.m. 1 Outline Wireless: 802.11 Mobile IP Cellular Networks: LTE Sample final 2 Wireless and Mobile Network Wireless access: WIFI

More information

ICE 1332/0715 Mobile Computing (Summer, 2008)

ICE 1332/0715 Mobile Computing (Summer, 2008) ICE 1332/0715 Mobile Computing (Summer, 2008) IEEE 802.11 Prof. Chansu Yu http://academic.csuohio.edu/yuc/ Contents Overview of IEEE 802.11 Frame formats MAC frame PHY frame IEEE 802.11 IEEE 802.11b IEEE

More information

3.1. Introduction to WLAN IEEE

3.1. Introduction to WLAN IEEE 3.1. Introduction to WLAN IEEE 802.11 WCOM, WLAN, 1 References [1] J. Schiller, Mobile Communications, 2nd Ed., Pearson, 2003. [2] Martin Sauter, "From GSM to LTE", chapter 6, Wiley, 2011. [3] wiki to

More information

Advanced Computer Networks WLAN

Advanced Computer Networks WLAN Advanced Computer Networks 263 3501 00 WLAN Patrick Stuedi Spring Semester 2014 1 Oriana Riva, Department of Computer Science ETH Zürich Last week Outlook Medium Access COPE Short Range Wireless Networks:

More information

Chapter 6 Wireless and Mobile Networks. Csci 4211 David H.C. Du

Chapter 6 Wireless and Mobile Networks. Csci 4211 David H.C. Du Chapter 6 Wireless and Mobile Networks Csci 4211 David H.C. Du Wireless LAN IEEE 802.11 a, b, g IEEE 802.15 Buletooth Hidden Terminal Effect Hidden Terminal Problem Hidden terminals A, C cannot hear each

More information

Computer Networks. Wireless LANs

Computer Networks. Wireless LANs Computer Networks Wireless LANs Mobile Communication Technology according to IEEE (examples) Local wireless networks WLAN 802.11 Personal wireless nw WPAN 802.15 WiFi 802.11a 802.11b 802.11h 802.11i/e/

More information

Wireless Communication and Networking CMPT 371

Wireless Communication and Networking CMPT 371 Wireless Communication and Networking CMPT 371 Wireless Systems: AM, FM Radio TV Broadcast Satellite Broadcast 2-way Radios Cordless Phones Satellite Links Mobile Telephony Systems Wireless Local Loop

More information

CMPE 257: Wireless and Mobile Networking

CMPE 257: Wireless and Mobile Networking CMPE 257: Wireless and Mobile Networking Katia Obraczka Computer Engineering UCSC Baskin Engineering Lecture 3 CMPE 257 Winter'11 1 Announcements Accessing secure part of the class Web page: User id: cmpe257.

More information