Agenda. What are we looking at? Introduction. Aim of the project. IP Routing

Size: px
Start display at page:

Download "Agenda. What are we looking at? Introduction. Aim of the project. IP Routing"

Transcription

1 Agenda Handoffs in Cellular Wireless Networks: The Daedalus Implementation & Experience by Shrinivasan Seshan, Hari Balakrishnan Randy H. Katz A short presentation by Aishvarya Sharma Dept of Computer Science TKK, Finland Introduction to the problem Purpose of the experiment Design Implementation Performance Analysis Overheads Conclusions and issues Introduction Focus is fast changing, if not already to mobile networking. Power, Mobility & Security remain the key issues Mobile networks suffer from dynamicity. Handoffs are expensive yet essential. Not many systems are operational that provide smooth handoffs with negligible latencies and data losses. What are we looking at? Standard IP routing in Internet is static in nature and seldom changes. Routing tables cannot be changed that frequently. Not a scalable solution. High delay jitter and data loss results are unacceptable for multimedia and for protocols like TCP/IP. Multimedia applications and reliable protocols adapt to long term delays and packet losses. But don t work well with frequent changes. IP Routing Data from mobile hosts (MH) to corresponding hosts (CH) use normal IP routing Trouble is for the downlink data that is to be sent to MH. Two stage delivery Packet delivery to Home Agent (maintains the location of the MH) Forwarding packets from HA to MH using either encapsulation, loose source routing or dynamic addresses. Aim of the project Design a handoff mechanism with low latencies and with minimum data loss Latencies less than ms Typical video is 3 frames/s, with one frame being worth ms. Uses multicast to send packets to nearby base stations together with intelligent buffering. Attempt to keep it similar to IETF Mobile IP routing. 1

2 IETF Mobile IP in brief IETF Mobile IP Routing Encapsulation Each mobile host is assigned a home network, that includes a home agent. Each time the routing changes, the home agent is notified. If the mobile moves far away from it s home agent, it leads to considerable delays Packets during handoffs are either lost or are delayed resulting in poor performance Multicast-based mobile IP routing Routing in proposed solution Uses multicast & intelligent buffering Achieves low latency handoff and reduced packet loss Three steps 1. Delivery of packet to home agent 2. Determine the physical location of mobile host. 3. Deliver packets from home agent to mobile host. Delivering of packet from HA to MH Determining current location of MH Each MH is assigned a long term IP corresponding to it s home location and a temporary multicast address. HA intercepts packets by proxy ARP Neighboring BS join the multicast group, but NOT the MH Each BS broadcasts a beacon MH keeps track of signal strength/quality, etc. MH decides which cell to join and future candidates. MH configures the multicast routing between HA and other BSs. BS for the cell containing the MH & neighboring cells as determined by the MH joins the IP group 2

3 Handoff messaging BS #1 MH BS #2 Handoffs PKT 1 beacon PKT2 buffer request pkt3 Handoff Latency Stronger Beacon Forward request PKT3 PKT4 Mobile initiated List of last few packets received by MH is given to new BS. To let BS determine which packets are already delivered. IETF uses Unicast instead of Multicast MH never joins the Multicast group, but controls which BS join the group and receive packets. Intelligent buffering help in low latencies and low data loss while keeping buffer size small. Idea is to use fixed network to maximum and use the scarce radio resources as less as possible Other Optimizations To reduce latencies VC Trees Splits wireless networks into regions Small regions lead to more handoffs, large regions put a load on the root nodes. Group-based routing Three layer hierarchy of MHs, BSs and supervisor systems. Static multicast groups Both define static regions where handoffs occur smoothly. Implementation WaveLAN 915 MHz Ethernet-like wireless radio Shared 2Mb/s CSMA/CA MAC-Layer Handoffs are between the two base stations connected over Ethernet Implementation 2 Consists of four modules Encapsulator At home Agent Decapsulator At Base Station Beaconing system Route analyzer At MH Modifications to the OS network stack Encapsulator 1/2 Resides at the home Agent When MH leaves home location, it initializes the home agent with a pre-defined multicast address. When MH is away, HA uses proxy ARP to respond to all ARP requests for MH and returns own MAC address so that all messages for MH are intercepted by him. HA kernel contains information about each MH (for which it s responsible) IP Address, Multicast address and TTL information. 3

4 Encapsulator 2/2 Decapsulator 1/2 Routing from CH to MH is done at each BS. On the primary BS, the packets are decapsulated and sent over the air to the MH. Other BSs buffer the packets instead. ~ 1 ms - buffer for x3 the latency time (< 3 ms ) For a data rate of 1.4 Mbps, and each packet of ~ 144 bytes, it implies storing around 12 packets Scans all multicast packets to identify the ones that are for the MH the BS is responsible for. It either buffers the packets (if just listening) or forwards the packets to the MH MH sends in the IP IDs of the last 3 packets received by it before sending a request to a new BS to transmit. Daemon listens to route analyzer (MH) via TCP connection for control signaling Decapsulator 2/2 Beaconing System 1/2 Runs on both MH and BS Primary responsibility to provide location information of MH to Route Analyzer. NIC card measures the signal strength, background noise and quality of received packet. But since this can be done only on reception of a packet, each BS periodically sends a beacon packet. (analogous to BCCH in GSM). Each beacon packet sent over UDP/IP contains IP address of wired and Wireless interfaces of the BS. A beacon frequency of 1 beacon/s yields in 1% degradation in bandwidth Beaconing System 1/2 Route Analyzer Determines the route of packets to mobile host. Two modules Information Retrieval Module Determines the neighbors of the MH Route Control Module Determines which BS is best for routing data Next best BS for a handoff Uses hysteresis 15% better signal strength for a handoff Nearby BS are requested for buffering Uses 3 type of policies 1. All BS in range to buffer packets 2. Fixed number of BS buffering at all times 3. Adapts the number of buffering BSs to rate of MH s motion. 4

5 Performance Analysis 1/4 Performance Analysis 2/4 Handoff Distance between BSs Handoff Latency No. of lost packets Multicast-based with buffering hops 1 hop 2 hops 3 hops Throughput achieved for TCP transfers to mobile host at various handoff frequencies In absence of handoffs, peak output is 1.45Mbps, 1% less than achieved from point-to-point. This is attributed to WaveLAN MAC-level effects. Measured with average transfer of 8 Mbytes of data Multicast but with no buffering No Multicasting and no buffering hops 1 hop 2 hops 3 hops hops 1 hop 2 hops 1-15 ms 1-15 ms 1-15 ms 15-2 ms ms 2-25 ms hops 25-3 ms 4-5 Performance Analysis 3/4 Performance Analysis 4/4 Handoff timings without multicasting and buffering stations at distance three Timing of handoffs in case of multicasting with buffering Protocol Overheads 1. Routing of packets to BS Triangle Routing Not the best route between MH and CH. Reasonable only if HA is near the best route. Alternative: Allow CH to transmit to BS too. Difficult! Multicast Implementation Experiment used DVMRP Better alternatives are available, with special support for mobility. Protocol Overheads 2/2 2. Buffering of Packets Consumes memory and bandwidth Avoid buffering at BS the MH does not visit. Physical layout Degree of overlap High vs. low Mobility Patterns Trade off between network resource consumption and improved handoff performance. Wired network layout of BS Additional network bandwidth by multicasting is acceptable if BSs are on the same physical broadcast-based network. So BS that tend to buffer packets together should be placed closer to each other. 5

6 Problems faced with WaveLAN Conclusions Implements CSMA/CA MAC-layer protocol Adjacent BS contend for the link based on CSMA/CA. Under heavy load, adjacent BS conflict and are denied access for much longer periods, even though if they had packets to send. This continues even when the adjacent BS becomes the primary BS. BS backs off to a point that it remains silent even if it should be transmitting. This leads to a latency of 2-95 ms, but not very often. Multicasting coupled with buffering at BS helps in achieving latencies of and with zero packet loss. Video playback and TCP don t notice any disruptions. Security can be an issue as MH needs to know the network topology. Should we always trust adjacent BS in the network? References Handoffs in Cellular Wireless Networks- The Daedalus Implementation and Experience vey/split/node49.html HO2.pdf 6

Improving Reliable Transport and Handoff Performance in Cellular Wireless Networks

Improving Reliable Transport and Handoff Performance in Cellular Wireless Networks Improving Reliable Transport and Handoff Performance in Cellular Wireless Networks H. Balakrishnan, S. Seshan, and R. H. Katz ACM Wireless Networks Vol. 1, No. 4, pp. 469-482 Dec. 1995 P. 1 Introduction

More information

Improving Reliable Transport and Handoff Performance in Cellular Wireless Networks 1

Improving Reliable Transport and Handoff Performance in Cellular Wireless Networks 1 In ACM Wireless Networks Journal (WINET), 1(4), December 1995. Improving Reliable Transport and Handoff Performance in Cellular Wireless Networks 1 Hari Balakrishnan, Srinivasan Seshan, and Randy H. Katz

More information

Improving reliable transport and handoff performance in cellular wireless networks 3

Improving reliable transport and handoff performance in cellular wireless networks 3 Wireless Networks 1 (1995) 469^481 469 Improving reliable transport and handoff performance in cellular wireless networks 3 Hari Balakrishnan, Srinivasan Seshan and Randy H. Katz Computer Science Division,

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

CIS 632 / EEC 687 Mobile Computing

CIS 632 / EEC 687 Mobile Computing CIS 632 / EEC 687 Mobile Computing TCP in Mobile Networks Prof. Chansu Yu Contents Physical layer issues Communication frequency Signal propagation Modulation and Demodulation Channel access issues Multiple

More information

Mobile Routing : Computer Networking. Overview. How to Handle Mobile Nodes? Mobile IP Ad-hoc network routing Assigned reading

Mobile Routing : Computer Networking. Overview. How to Handle Mobile Nodes? Mobile IP Ad-hoc network routing Assigned reading Mobile Routing 15-744: Computer Networking L-10 Ad Hoc Networks Mobile IP Ad-hoc network routing Assigned reading Performance Comparison of Multi-Hop Wireless Ad Hoc Routing Protocols A High Throughput

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

Daedalus/GloMop Architectural Walkthrough

Daedalus/GloMop Architectural Walkthrough Daedalus/ Architectural Walkthrough Daedalus Retreat, Lake Tahoe June 18-20th, 1996 Steve Gribble and Todd Hodes {gribble,hodes}@cs.berkeley.edu Outline Motivation and overview Core architecture components

More information

Wireless Challenges : Computer Networking. Overview. Routing to Mobile Nodes. Lecture 24: Mobile and Wireless

Wireless Challenges : Computer Networking. Overview. Routing to Mobile Nodes. Lecture 24: Mobile and Wireless Wireless Challenges 15-441: Computer Networking Lecture 24: Mobile and Wireless Peter Steenkiste Fall 2010 www.cs.cmu.edu/~prs/15-441-f10 Force us to rethink many assumptions Need to share airwaves rather

More information

No lecture on Thurs. Last homework will be out this week (not due, covers wireless) Extra office hours for next week and the week after.

No lecture on Thurs. Last homework will be out this week (not due, covers wireless) Extra office hours for next week and the week after. Administrivia No lecture on Thurs. Last homework will be out this week (not due, covers wireless) Extra office hours for next week and the week after. 1 CSMA/CA: Recap Sensing in wireless medium is limited

More information

More wireless: Sensor networks and TCP on mobile hosts

More wireless: Sensor networks and TCP on mobile hosts More wireless: Sensor networks and TCP on mobile hosts CSU CS557, Spring 2018 Instructor: Lorenzo De Carli (Slides by Christos Papadopoulos, remixed by Lorenzo De Carli) Outline Routing in sensor networks

More information

Wireless TCP. TCP mechanism. Wireless Internet: TCP in Wireless. Wireless TCP: transport layer

Wireless TCP. TCP mechanism. Wireless Internet: TCP in Wireless. Wireless TCP: transport layer Wireless TCP W.int.2-2 Wireless Internet: TCP in Wireless Module W.int.2 Mobile IP: layer, module W.int.1 Wireless TCP: layer Dr.M.Y.Wu@CSE Shanghai Jiaotong University Shanghai, China Dr.W.Shu@ECE University

More information

A Seamless Handover Mechanism for IEEE e Broadband Wireless Access

A Seamless Handover Mechanism for IEEE e Broadband Wireless Access A Seamless Handover Mechanism for IEEE 802.16e Broadband Wireless Access Kyung-ah Kim 1, Chong-Kwon Kim 2, and Tongsok Kim 1 1 Marketing & Technology Lab., KT, Seoul, Republic of Korea {kka1, tongsok}@kt.co.kr

More information

SIP-based Mobility Architecture for Next Generation Wireless Networks

SIP-based Mobility Architecture for Next Generation Wireless Networks SIP-based Mobility Architecture for Next Generation Wireless Networks PerCom IEEE 2005 Presented by T.C. Lin 2006/01/25 Outline Introduction Overview of SIP Problem Description Proposed Architecture Performance

More information

ECS-087: Mobile Computing

ECS-087: Mobile Computing ECS-087: Mobile Computing TCP over wireless TCP and mobility Most of the Slides borrowed from Prof. Sridhar Iyer s lecture IIT Bombay Diwakar Yagyasen 1 Effect of Mobility on Protocol Stack Application:

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

CE693: Adv. Computer Networking

CE693: Adv. Computer Networking CE693: Adv. Computer Networking L-10 Wireless Broadcast Fall 1390 Acknowledgments: Lecture slides are from the graduate level Computer Networks course thought by Srinivasan Seshan at CMU. When slides are

More information

Communications Software. CSE 123b. CSE 123b. Spring Lecture 10: Mobile Networking. Stefan Savage

Communications Software. CSE 123b. CSE 123b. Spring Lecture 10: Mobile Networking. Stefan Savage CSE 123b CSE 123b Communications Software Spring 2003 Lecture 10: Mobile Networking Stefan Savage Quick announcement My office hours tomorrow are moved to 12pm May 6, 2003 CSE 123b -- Lecture 10 Mobile

More information

Quick announcement. CSE 123b Communications Software. Last class. Today s issues. The Mobility Problem. Problems. Spring 2003

Quick announcement. CSE 123b Communications Software. Last class. Today s issues. The Mobility Problem. Problems. Spring 2003 CSE 123b Communications Software Quick announcement My office hours tomorrow are moved to 12pm Spring 2003 Lecture 10: Mobile Networking Stefan Savage May 6, 2003 CSE 123b -- Lecture 10 Mobile IP 2 Last

More information

CSE 123A Computer Netwrking

CSE 123A Computer Netwrking CSE 123A Computer Netwrking Winter 2005 Mobile Networking Alex Snoeren presenting in lieu of Stefan Savage Today s s issues What are implications of hosts that move? Remember routing? It doesn t work anymore

More information

tcheng Lin Tan, *Stephen Pink

tcheng Lin Tan, *Stephen Pink A Fast Handoff Scheme for Wireless Networks tcheng Lin Tan, *Stephen Pink SKin Mun Lye t*computer Science & Electrical Engineering tscentre for Wireless Communications Luled University of Technology National

More information

Mobile Communications. Ad-hoc and Mesh Networks

Mobile Communications. Ad-hoc and Mesh Networks Ad-hoc+mesh-net 1 Mobile Communications Ad-hoc and Mesh Networks Manuel P. Ricardo Faculdade de Engenharia da Universidade do Porto Ad-hoc+mesh-net 2 What is an ad-hoc network? What are differences between

More information

Lecture 4: Wireless MAC Overview. Hung-Yu Wei National Taiwan University

Lecture 4: Wireless MAC Overview. Hung-Yu Wei National Taiwan University Lecture 4: Wireless MAC Overview Hung-Yu Wei National Taiwan University Medium Access Control Topology 3 Simplex and Duplex 4 FDMA TDMA CDMA DSSS FHSS Multiple Access Methods Notice: CDMA and spread spectrum

More information

CSE 123b Communications Software

CSE 123b Communications Software CSE 123b Communications Software Spring 2004 Lecture 9: Mobile Networking Stefan Savage Quick announcements Typo in problem #1 of HW #2 (fixed as of 1pm yesterday) Please consider chapter 4.3-4.3.3 to

More information

Quick announcements. CSE 123b Communications Software. Today s issues. Last class. The Mobility Problem. Problems. Spring 2004

Quick announcements. CSE 123b Communications Software. Today s issues. Last class. The Mobility Problem. Problems. Spring 2004 CSE 123b Communications Software Spring 2004 Lecture 9: Mobile Networking Quick announcements Typo in problem #1 of HW #2 (fixed as of 1pm yesterday) Please consider chapter 4.3-4.3.3 to be part of the

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

Computer Network Fundamentals Spring Week 3 MAC Layer Andreas Terzis

Computer Network Fundamentals Spring Week 3 MAC Layer Andreas Terzis Computer Network Fundamentals Spring 2008 Week 3 MAC Layer Andreas Terzis Outline MAC Protocols MAC Protocol Examples Channel Partitioning TDMA/FDMA Token Ring Random Access Protocols Aloha and Slotted

More information

SWAP and TCP performance

SWAP and TCP performance SWAP and TCP performance Jean Tourrilhes, HPLB 23 March 98 1 Introduction The SWAP protocol that we have proposed [4] the HRFWG is designed to carry TCP/IP traffic. Of course, we would never had proposed

More information

Optimized Paging Cache Mappings for efficient location management Hyun Jun Lee, Myoung Chul Jung, and Jai Yong Lee

Optimized Paging Cache Mappings for efficient location management Hyun Jun Lee, Myoung Chul Jung, and Jai Yong Lee Optimized Paging Cache Mappings for efficient location management Hyun Jun Lee, Myoung Chul Jung, and Jai Yong Lee Abstract Cellular IP maintains distributed cache for location management and routing purposes.

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

Comparison of IP Micro-Mobility Protocols

Comparison of IP Micro-Mobility Protocols Comparison of IP Micro-Mobility Protocols Andrew T. Campbell, Javier Gomez, Sanghyo Kim, Chieh-Yih Wan COMET Group, Columbia University, New York Zoltán R. Turányi, András G. Valkó, Traffic Laboratory,

More information

Wireless Mesh Networks

Wireless Mesh Networks Distributed Systems 600.437 Wireless Mesh Networks Department of Computer Science The Johns Hopkins University 1 Wireless Mesh Networks Lecture 10 Further reading: www.dsn.jhu.edu/publications/ 2 The Wireless

More information

FAST HANDOFF WITH POSITION INFORMATION FOR MOBILE IP

FAST HANDOFF WITH POSITION INFORMATION FOR MOBILE IP FAST HANDOFF WITH POSITION INFORMATION FOR MOBILE IP by Mustafa Ergen, Sinem Coleri, Baris Dundar, Anuj Puri, Jean Walrand, Pravin Varaiya Department of Electrical Engineering and Computer Science UNIVERSITY

More information

19: Networking. Networking Hardware. Mark Handley

19: Networking. Networking Hardware. Mark Handley 19: Networking Mark Handley Networking Hardware Lots of different hardware: Modem byte at a time, FDDI, SONET packet at a time ATM (including some DSL) 53-byte cell at a time Reality is that most networking

More information

Chapter 7 CONCLUSION

Chapter 7 CONCLUSION 97 Chapter 7 CONCLUSION 7.1. Introduction A Mobile Ad-hoc Network (MANET) could be considered as network of mobile nodes which communicate with each other without any fixed infrastructure. The nodes in

More information

Principles behind data link layer services:

Principles behind data link layer services: Data link layer Goals: Principles behind data link layer services: Error detection, correction Sharing a broadcast channel: Multiple access Link layer addressing Reliable data transfer, flow control Example

More information

Principles behind data link layer services:

Principles behind data link layer services: Data link layer Goals: Principles behind data link layer services: Error detection, correction Sharing a broadcast channel: Multiple access Link layer addressing Reliable data transfer, flow control Example

More information

Homework 1. Question 1 - Layering. CSCI 1680 Computer Networks Fonseca

Homework 1. Question 1 - Layering. CSCI 1680 Computer Networks Fonseca CSCI 1680 Computer Networks Fonseca Homework 1 Due: 27 September 2012, 4pm Question 1 - Layering a. Why are networked systems layered? What are the advantages of layering? Are there any disadvantages?

More information

What is Multicasting? Multicasting Fundamentals. Unicast Transmission. Agenda. L70 - Multicasting Fundamentals. L70 - Multicasting Fundamentals

What is Multicasting? Multicasting Fundamentals. Unicast Transmission. Agenda. L70 - Multicasting Fundamentals. L70 - Multicasting Fundamentals What is Multicasting? Multicasting Fundamentals Unicast transmission transmitting a packet to one receiver point-to-point transmission used by most applications today Multicast transmission transmitting

More information

SJTU 2018 Fall Computer Networking. Wireless Communication

SJTU 2018 Fall Computer Networking. Wireless Communication SJTU 2018 Fall Computer Networking 1 Wireless Communication Internet Protocol Stack 2 Application: supporting network applications - FTP, SMTP, HTTP Transport: data transfer between processes - TCP, UDP

More information

Architecture and Prototyping of an based Self-Organizing Hierarchical Ad-Hoc Wireless Network (SOHAN)

Architecture and Prototyping of an based Self-Organizing Hierarchical Ad-Hoc Wireless Network (SOHAN) Architecture and Prototyping of an 802.11- based Self-Organizing Hierarchical Ad-Hoc Wireless Network (SOHAN) PIMRC 2004, Barcelona Sept 5-8, 2004 S. Ganu, L. Raju, B. Anepu, S. Zhao, I. Seskar and D.

More information

University of Würzburg Institute of Computer Science Research Report Series. Performance Comparison of Handover Mechanisms in Wireless LAN Networks

University of Würzburg Institute of Computer Science Research Report Series. Performance Comparison of Handover Mechanisms in Wireless LAN Networks University of Würzburg Institute of Computer Science Research Report Series Performance Comparison of Handover Mechanisms in Wireless LAN Networks Rastin Pries and Klaus Heck Report No. 339 September 2004

More information

WPAN/WBANs: ZigBee. Dmitri A. Moltchanov kurssit/elt-53306/

WPAN/WBANs: ZigBee. Dmitri A. Moltchanov    kurssit/elt-53306/ WPAN/WBANs: ZigBee Dmitri A. Moltchanov E-mail: dmitri.moltchanov@tut.fi http://www.cs.tut.fi/ kurssit/elt-53306/ IEEE 802.15 WG breakdown; ZigBee Comparison with other technologies; PHY and MAC; Network

More information

Mobile IP. Mobile Computing. Mobility versus Portability

Mobile IP. Mobile Computing. Mobility versus Portability Mobile IP Mobile Computing Introduction Amount of mobile/nomadic computing expected to increase dramatically in near future. By looking at the great acceptance of mobile telephony, one can foresee a similar

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

Design and Evaluation of a new MAC Protocol for Long- Distance Mesh Networks by Bhaskaran Raman & Kameswari Chebrolu ACM Mobicom 2005

Design and Evaluation of a new MAC Protocol for Long- Distance Mesh Networks by Bhaskaran Raman & Kameswari Chebrolu ACM Mobicom 2005 Design and Evaluation of a new MAC Protocol for Long- Distance 802.11 Mesh Networks by Bhaskaran Raman & Kameswari Chebrolu ACM Mobicom 2005 Reviewed by Anupama Guha Thakurta CS525M - Mobile and Ubiquitous

More information

TCP PERFORMANCE FOR FUTURE IP-BASED WIRELESS NETWORKS

TCP PERFORMANCE FOR FUTURE IP-BASED WIRELESS NETWORKS TCP PERFORMANCE FOR FUTURE IP-BASED WIRELESS NETWORKS Deddy Chandra and Richard J. Harris School of Electrical and Computer System Engineering Royal Melbourne Institute of Technology Melbourne, Australia

More information

Networking. Bin Li Assistant Professor Dept. of Electrical, Computer and Biomedical Engineering University of Rhode Island

Networking. Bin Li Assistant Professor Dept. of Electrical, Computer and Biomedical Engineering University of Rhode Island Networking Bin Li Assistant Professor Dept. of Electrical, Computer and Biomedical Engineering University of Rhode Island Why is Networking Needed? To enhance many devices Cars communicating to reduce

More information

Mobility Support in Internet and Mobile IP. Gianluca Reali

Mobility Support in Internet and Mobile IP. Gianluca Reali Mobility Support in Internet and Mobile IP Gianluca Reali 1 Problem We have seen that mobile users can change point of attachment In a WLAN, a mobile may change access point. In a cellular network, a mobile

More information

CS 428/528 Computer Networks Lecture 01. Yan Wang

CS 428/528 Computer Networks Lecture 01. Yan Wang 1 CS 428/528 Computer Lecture 01 Yan Wang 2 Motivation: Why bother? Explosive growth of networks 1989, 100,000 hosts on the Internet Distributed Applications and Systems E-mail, WWW, multimedia, distributed

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 10 CMPE 257 Spring'15 1 Student Presentations Schedule May 21: Sam and Anuj May 26: Larissa

More information

CS 515 Mobile and Wireless Networking Final Exam Solutions Fall

CS 515 Mobile and Wireless Networking Final Exam Solutions Fall Bilkent University Computer Engineering Department CS 515 Mobile and Wireless Networking Final Exam Solutions Fall 2002-2003 Date: January 10, 2003, Friday Duration: 120 minutes Name of the Student ID

More information

The Effects of Asymmetry on TCP Performance

The Effects of Asymmetry on TCP Performance The Effects of Asymmetry on TCP Performance Hari Balakrishnan Venkata N. Padmanabhan Randy H. Katz University of California at Berkeley Daedalus/BARWAN Retreat June 1997 Outline Overview Bandwidth asymmetry

More information

Principles behind data link layer services

Principles behind data link layer services Data link layer Goals: Principles behind data link layer services Error detection, correction Sharing a broadcast channel: Multiple access Link layer addressing Reliable data transfer, flow control: Done!

More information

CS 515 Mobile and Wireless Networking Final Exam Fall

CS 515 Mobile and Wireless Networking Final Exam Fall Bilkent University Computer Engineering Department CS 515 Mobile and Wireless Networking Final Exam Fall 2002-2003 Date: January 10, 2003, Friday Duration: 120 minutes Name of the Student ID of the Student

More information

CS5984 Mobile Computing

CS5984 Mobile Computing CS5984 Mobile Computing Dr. Ayman Abdel-Hamid Computer Science Department Virginia Tech Mobile IPv4 Micro-mobility 1 Outline solutions 2 Local-area Mobility Solutions Within the Mobile IP framework Regional

More information

LECTURE 8. Mobile IP

LECTURE 8. Mobile IP 1 LECTURE 8 Mobile IP What is Mobile IP? The Internet protocol as it exists does not support mobility Mobile IP tries to address this issue by creating an anchor for a mobile host that takes care of packet

More information

Medium Access Protocols

Medium Access Protocols Medium Access Protocols Summary of MAC protocols What do you do with a shared media? Channel Partitioning, by time, frequency or code Time Division,Code Division, Frequency Division Random partitioning

More information

Wireless Network and Mobility

Wireless Network and Mobility Wireless Network and Mobility Dept. of Computer Science, University of Rochester 2008-11-17 CSC 257/457 - Fall 2008 1 Wireless Networks and Mobility Wireless networking in the data link layer Short range:

More information

CDMA-Based MAC Protocol for Wireless Ad Hoc Networks

CDMA-Based MAC Protocol for Wireless Ad Hoc Networks CDMA-Based MAC Protocol for Wireless Ad Hoc Networks Alaa Muqattash and Marwan Krunz Presented by: Habibullah Pagarkar for 600.647-Advanced Topics in Wireless Networks. JHU. Spring 04 Today s Presentation

More information

Subject: Adhoc Networks

Subject: Adhoc Networks ISSUES IN AD HOC WIRELESS NETWORKS The major issues that affect the design, deployment, & performance of an ad hoc wireless network system are: Medium Access Scheme. Transport Layer Protocol. Routing.

More information

The Importance of Being Opportunistic

The Importance of Being Opportunistic High Performance Switching and Routing Telecom Center Workshop: Sept 4, 1997. The Importance of Being Opportunistic Sachin Katti Dina Katabi, Wenjun Hu, Hariharan Rahul, and Muriel Medard Bandwidth is

More information

Baltzer Journals November 5, Fast and Scalable Wireless Handos. in Support of Mobile Internet Audio

Baltzer Journals November 5, Fast and Scalable Wireless Handos. in Support of Mobile Internet Audio Baltzer Journals November 5, 1998 Fast and Scalable Wireless Handos in Support of Mobile Internet Audio Ramon Caceres Venkata N. Padmanabhan AT&T Labs { Research Computer Science Division 180 Park Avenue

More information

Fast Handoff for Seamless Wireless Mesh Networks

Fast Handoff for Seamless Wireless Mesh Networks Fast Handoff for Seamless Wireless Mesh Networks Yair Amir, Claudiu Danilov, Michael Hilsdale, Raluca Musaloiu-Elefteri, Nilo Rivera Distributed Systems and Networks Lab Johns Hopkins University MobiSys

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

IEEE C /26. IEEE Working Group on Mobile Broadband Wireless Access <http://grouper.ieee.org/groups/802/20/>

IEEE C /26. IEEE Working Group on Mobile Broadband Wireless Access <http://grouper.ieee.org/groups/802/20/> 2003-03-09 IEEE C802.20-03/26 Project Title Date Submitted IEEE 802.20 Working Group on Mobile Broadband Wireless Access Architectural Attributes of an IP-based

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 8 CMPE 257 Spring'15 1 Announcements Project proposals. Feedback. Class schedule updated. Exam:

More information

Chapter 5 Ad Hoc Wireless Network. Jang Ping Sheu

Chapter 5 Ad Hoc Wireless Network. Jang Ping Sheu Chapter 5 Ad Hoc Wireless Network Jang Ping Sheu Introduction Ad Hoc Network is a multi-hop relaying network ALOHAnet developed in 1970 Ethernet developed in 1980 In 1994, Bluetooth proposed by Ericsson

More information

ICE 1332/0715 Mobile Computing (Summer, 2008)

ICE 1332/0715 Mobile Computing (Summer, 2008) ICE 1332/0715 Mobile Computing (Summer, 2008) TCP in Mobile Networks Prof. Chansu Yu http://academic.csuohio.edu/yuc/ c.yu91@csuohio.edu Contents Vinton Cerf and Robert Kahn s paper in 1973 introduces

More information

Fixed Internetworking Protocols and Networks. IP mobility. Rune Hylsberg Jacobsen Aarhus School of Engineering

Fixed Internetworking Protocols and Networks. IP mobility. Rune Hylsberg Jacobsen Aarhus School of Engineering Fixed Internetworking Protocols and Networks IP mobility Rune Hylsberg Jacobsen Aarhus School of Engineering rhj@iha.dk 1 2011 ITIFN Mobile computing Vision Seamless, ubiquitous network access for mobile

More information

Chapter 16 Networking

Chapter 16 Networking Chapter 16 Networking Outline 16.1 Introduction 16.2 Network Topology 16.3 Network Types 16.4 TCP/IP Protocol Stack 16.5 Application Layer 16.5.1 Hypertext Transfer Protocol (HTTP) 16.5.2 File Transfer

More information

IPv6 Stack. 6LoWPAN makes this possible. IPv6 over Low-Power wireless Area Networks (IEEE )

IPv6 Stack. 6LoWPAN makes this possible. IPv6 over Low-Power wireless Area Networks (IEEE ) Reference: 6LoWPAN: The Wireless Embedded Internet, Shelby & Bormann What is 6LoWPAN? 6LoWPAN makes this possible - Low-power RF + IPv6 = The Wireless Embedded Internet IPv6 over Low-Power wireless Area

More information

An efficient trigger to improve intra-wifi handover performance

An efficient trigger to improve intra-wifi handover performance An efficient trigger to improve intra-wifi handover performance Roberta Fracchia, Guillaume Vivier Motorola Labs, Parc les Algorithmes, Saint-Aubin, 91193 Gif-sur-Yvette, France Abstract Seamless mobility

More information

Input ports, switching fabric, output ports Switching via memory, bus, crossbar Queueing, head-of-line blocking

Input ports, switching fabric, output ports Switching via memory, bus, crossbar Queueing, head-of-line blocking Last time Router internals Input ports, switching fabric, output ports Switching via memory, bus, crossbar Queueing, head-of-line blocking Mobility Home, visited s Home, foreign agents Permanent, care-of

More information

CS 268: Computer Networking. Taking Advantage of Broadcast

CS 268: Computer Networking. Taking Advantage of Broadcast CS 268: Computer Networking L-12 Wireless Broadcast Taking Advantage of Broadcast Opportunistic forwarding Network coding Assigned reading XORs In The Air: Practical Wireless Network Coding ExOR: Opportunistic

More information

OPTIMIZING MOBILITY MANAGEMENT IN FUTURE IPv6 MOBILE NETWORKS

OPTIMIZING MOBILITY MANAGEMENT IN FUTURE IPv6 MOBILE NETWORKS OPTIMIZING MOBILITY MANAGEMENT IN FUTURE IPv6 MOBILE NETWORKS Sandro Grech Nokia Networks (Networks Systems Research) Supervisor: Prof. Raimo Kantola 1 SANDRO GRECH - OPTIMIZING MOBILITY MANAGEMENT IN

More information

Getting Connected (Chapter 2 Part 4) Networking CS 3470, Section 1 Sarah Diesburg

Getting Connected (Chapter 2 Part 4) Networking CS 3470, Section 1 Sarah Diesburg Getting Connected (Chapter 2 Part 4) Networking CS 3470, Section 1 Sarah Diesburg Five Problems Encoding/decoding Framing Error Detection Error Correction Media Access Five Problems Encoding/decoding Framing

More information

Solutions to Performance Problems in VoIP Over a Wireless LAN

Solutions to Performance Problems in VoIP Over a Wireless LAN Solutions to Performance Problems in VoIP Over a 802.11 Wireless LAN Wei Wang, Soung C. Liew, and VOK Li, Solutions to Performance Problems in VoIP over a 802.11 Wireless LAN, IEEE Transactions On Vehicular

More information

Outline : Wireless Networks Lecture 10: Management. Management and Control Services : Infrastructure Reminder.

Outline : Wireless Networks Lecture 10: Management. Management and Control Services : Infrastructure Reminder. Outline 18-759: Wireless Networks Lecture 10: 802.11 Management Peter Steenkiste Departments of Computer Science and Electrical and Computer Engineering Spring Semester 2016 http://www.cs.cmu.edu/~prs/wirelesss16/

More information

Mobility: vocabulary

Mobility: vocabulary What is mobility? spectrum of mobility, from the perspective: no mobility high mobility mobile wireless user, using same access point mobile user, connecting/ disconnecting from using DHCP. mobile user,

More information

Outline. Circuit Switching. Circuit Switching : Introduction to Telecommunication Networks Lectures 13: Virtual Things

Outline. Circuit Switching. Circuit Switching : Introduction to Telecommunication Networks Lectures 13: Virtual Things 8-5: Introduction to Telecommunication Networks Lectures : Virtual Things Peter Steenkiste Spring 05 www.cs.cmu.edu/~prs/nets-ece Outline Circuit switching refresher Virtual Circuits - general Why virtual

More information

Computer Communication & Networks / Data Communication & Computer Networks Week # 03

Computer Communication & Networks / Data Communication & Computer Networks Week # 03 Computer Communication & Networks / Data Communication & Computer Networks Week # 03 M.Nadeem Akhtar CS & IT Department The University of Lahore Email: nadeem.akhtar@cs.uol.edu.pk URL-https://sites.google.com/site/nadeemuolcsccn/home

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

3. Evaluation of Selected Tree and Mesh based Routing Protocols

3. Evaluation of Selected Tree and Mesh based Routing Protocols 33 3. Evaluation of Selected Tree and Mesh based Routing Protocols 3.1 Introduction Construction of best possible multicast trees and maintaining the group connections in sequence is challenging even in

More information

CSC 4900 Computer Networks: Mobility

CSC 4900 Computer Networks: Mobility CSC 4900 Computer Networks: Mobility Professor Henry Carter Fall 2017 Last Time What is the hidden terminal problem? How do CDMA networks use spectrum differently than TDMA systems? What is a chipping

More information

Wireless Heterogeneity. EEC173B/ECS152C, Spring 09. Data Transport Over Wireless. Wireless Performance. Reliable Data Transport over Wireless Networks

Wireless Heterogeneity. EEC173B/ECS152C, Spring 09. Data Transport Over Wireless. Wireless Performance. Reliable Data Transport over Wireless Networks EEC73B/ECSC, Spring 9 Reliable Data over Wireless s Problems with TCP Snoop Protocol Metricom Ricochet Wireless Heterogeneity Lucent WaveLAN Regional-Area Metro-Area Cellular Digital IBM Infrared Packet

More information

A local area network that employs either a full mesh topology or partial mesh topology

A local area network that employs either a full mesh topology or partial mesh topology and Ad Hoc Networks Definition A local area network that employs either a full mesh topology or partial mesh topology Full mesh topology each node is connected directly to each of the others Partial mesh

More information

Lecture 5 The Data Link Layer. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it

Lecture 5 The Data Link Layer. Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Lecture 5 The Data Link Layer Antonio Cianfrani DIET Department Networking Group netlab.uniroma1.it Link Layer: setting the context two physically connected devices: host-router, router-router, host-host,

More information

Multicast overview. Introduction to multicast. Information transmission techniques. Unicast

Multicast overview. Introduction to multicast. Information transmission techniques. Unicast Contents Multicast overview 1 Introduction to multicast 1 Information transmission techniques 1 Multicast features 3 Common notations in multicast 4 Multicast advantages and applications 4 Multicast models

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

Configuring Advanced Radio Settings on the WAP371

Configuring Advanced Radio Settings on the WAP371 Article ID: 5069 Configuring Advanced Radio Settings on the WAP371 Objective Radio settings are used to configure the wireless radio antenna and its properties on the wireless access point (WAP) device

More information

Data Link Layer. Our goals: understand principles behind data link layer services: instantiation and implementation of various link layer technologies

Data Link Layer. Our goals: understand principles behind data link layer services: instantiation and implementation of various link layer technologies Data Link Layer Our goals: understand principles behind data link layer services: link layer addressing instantiation and implementation of various link layer technologies 1 Outline Introduction and services

More information

Selective Establishment of Pseudo Reservations for QoS Guarantees in Mobile Internet

Selective Establishment of Pseudo Reservations for QoS Guarantees in Mobile Internet Selective Establishment of Pseudo Reservations for QoS Guarantees in Mobile Internet Kyounghee Lee, Myungchul Kim, Sungwon Kang and Jonghyun Lee School of Engineering, Information and Communications University,

More information

Multicast overview. Introduction to multicast. Information transmission techniques. Unicast

Multicast overview. Introduction to multicast. Information transmission techniques. Unicast Contents Multicast overview 1 Introduction to multicast 1 Information transmission techniques 1 Multicast features 3 Common notations in multicast 4 Multicast benefits and applications 4 Multicast models

More information

WISNETWORKS. WisOS 11ac V /3/21. Software version WisOS 11ac

WISNETWORKS. WisOS 11ac V /3/21. Software version WisOS 11ac WISNETWORKS User Manual V1.1 2016/3/21 Software version 1.0.0021 Table of contents 1. Setup& WMI... 3 1.1 Hardware Setup... 3 1.2 Web Management Interface... 3 2. Status... 4 2.1 Overview... 4 2.1.1 System...

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

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

Throughput & Latency Control in Ethernet Backplane Interconnects. Manoj Wadekar Gary McAlpine. Intel

Throughput & Latency Control in Ethernet Backplane Interconnects. Manoj Wadekar Gary McAlpine. Intel Throughput & Latency Control in Ethernet Backplane Interconnects Manoj Wadekar Gary McAlpine Intel Date 3/16/04 Agenda Discuss Backplane challenges to Ethernet Simulation environment and definitions Preliminary

More information

XORs in the Air: Practical Wireless Network Coding

XORs in the Air: Practical Wireless Network Coding XORs in the Air: Practical Wireless Network Coding S. Katti, H. Rahul, W. Hu, D. Katabi, M. Medard, J. Crowcroft MIT & University of Cambridge Can we use 3 transmissions to send traffic? 1 2 4 3 Can we

More information

ARPA Mobile Information Systems Applications Workshop December 7-8, Mobile Networking

ARPA Mobile Information Systems Applications Workshop December 7-8, Mobile Networking ARPA Mobile Information Systems Applications Workshop December 7-8, 1995 Mobile Networking Randy H. Katz CS Division EECS Department University of California, Berkeley 1 Mobile Networking Middleware Reliable

More information