Efficient Internet Traffic Delivery over Wireless Networks Sandhya Sumathy.

Slides:



Advertisements
Similar presentations
Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 1 Chapter 9 Fundamentals.
Advertisements

Congestion Control and Fairness Models Nick Feamster CS 4251 Computer Networking II Spring 2008.
Multi-Access Services in Heterogeneous Wireless Networks Kameswari Chebrolu, Ramesh R. Rao Abstract Today's wireless world is characterized by heterogeneity.
Advanced satellite infrastructures in future global Grid computing: network solutions to compensate delivery delay Blasco Bonito, Alberto Gotta and Raffaello.
Computer Networking Lecture 20 – Queue Management and QoS.
Improving TCP over Wireless by Selectively Protecting Packet Transmissions Carla F. Chiasserini Michele Garetto Michela Meo Dipartimento di Elettronica.
CSIT560 Internet Infrastructure: Switches and Routers Active Queue Management Presented By: Gary Po, Henry Hui and Kenny Chong.
Congestion Control Reasons: - too many packets in the network and not enough buffer space S = rate at which packets are generated R = rate at which receivers.
Improving TCP Performance over Mobile Ad Hoc Networks by Exploiting Cross- Layer Information Awareness Xin Yu Department Of Computer Science New York University,
Comparison and Analysis of FIFO, PQ, and WFQ Disciplines on multimedia
The War Between Mice and Elephants LIANG GUO, IBRAHIM MATTA Computer Science Department Boston University ICNP (International Conference on Network Protocols)
Prentice HallHigh Performance TCP/IP Networking, Hassan-Jain Chapter 10 TCP/IP Performance over Asymmetric Networks.
Computer Communication1 Computer Communications Summary.
UNIT 07 Process – to – Process Delivery: UDP,TCP and SCTP
Congestion control in data centers
Adaptive Packet Marking for Maintaining End-to-End Throughput in a Differentiated-Services Internet Wu-Chang Feng, Dilip D.Kandlur, Member, IEEE, Debanjan.
Internet Networking Spring 2003 Tutorial 12 Limited Transmit RFC 3042 Long Thin Networks RFC 2757.
Analysis and Simulation of a Fair Queuing Algorithm
Congestion Control and Resource Allocation
1 TCP Transport Control Protocol Reliable In-order delivery Flow control Responds to congestion “Nice” Protocol.
1 Internet Networking Spring 2003 Tutorial 11 Explicit Congestion Notification (RFC 3168)
A Real-Time Video Multicast Architecture for Assured Forwarding Services Ashraf Matrawy, Ioannis Lambadaris IEEE TRANSACTIONS ON MULTIMEDIA, AUGUST 2005.
ACN: Congestion Control1 Congestion Control and Resource Allocation.
1 Spring Semester 2007, Dept. of Computer Science, Technion Internet Networking recitation #8 Explicit Congestion Notification (RFC 3168) Limited Transmit.
CMPE 257 Spring CMPE 257: Wireless and Mobile Networking Spring 2005 E2E Protocols (point-to-point)
Computer Communication1 Computer Communications Summary.
1 A Comparison of Mechanisms for Improving TCP Performance over Wireless Links Course : CS898T Instructor : Dr.Chang - Swapna Sunkara.
Congestion Control for High Bandwidth-delay Product Networks Dina Katabi, Mark Handley, Charlie Rohrs.
Proxy-based TCP over mobile nets1 Proxy-based TCP-friendly streaming over mobile networks Frank Hartung Uwe Horn Markus Kampmann Presented by Rob Elkind.
Enhancing TCP Fairness in Ad Hoc Wireless Networks Using Neighborhood RED Kaixin Xu, Mario Gerla University of California, Los Angeles {xkx,
Advanced Network Architecture Research Group 2001/11/149 th International Conference on Network Protocols Scalable Socket Buffer Tuning for High-Performance.
1 Semester 2 Module 10 Intermediate TCP/IP Yuda college of business James Chen
Adaptive Failover Mechanism Motivation End-to-end connectivity can suffer during net failures Internet path outage detection and recovery is slow (shown.
A Simple and Effective Cross Layer Networking System for Mobile Ad Hoc Networks Wing Ho Yuen, Heung-no Lee and Timothy Andersen.
Improving TCP Performance over Wireless Networks with Collaborative Multi-homed Mobile Hosts Kyu-Han Kim and Kang G. Shin Department of Electrical Engineering.
CA-RTO: A Contention- Adaptive Retransmission Timeout I. Psaras, V. Tsaoussidis, L. Mamatas Demokritos University of Thrace, Xanthi, Greece This study.
Transport over Wireless Networks Myungchul Kim
Transport Control Protocol (TCP) Features of TCP, packet loss and retransmission, adaptive retransmission, flow control, three way handshake, congestion.
27th, Nov 2001 GLOBECOM /16 Analysis of Dynamic Behaviors of Many TCP Connections Sharing Tail-Drop / RED Routers Go Hasegawa Osaka University, Japan.
Covilhã, 30 June Atílio Gameiro Page 1 The information in this document is provided as is and no guarantee or warranty is given that the information is.
Advanced Network Architecture Research Group 2001/11/74 th Asia-Pacific Symposium on Information and Telecommunication Technologies Design and Implementation.
ﺑﺴﻢﺍﷲﺍﻠﺭﺣﻣﻥﺍﻠﺭﺣﻳﻡ. Group Members Nadia Malik01 Malik Fawad03.
HighSpeed TCP for High Bandwidth-Delay Product Networks Raj Kettimuthu.
Requirements for Simulation and Modeling Tools Sally Floyd NSF Workshop August 2005.
TCP Trunking: Design, Implementation and Performance H.T. Kung and S. Y. Wang.
CROSS-LAYER OPTIMIZATION PRESENTED BY M RAHMAN ID:
Analysis of Buffer Size in Core Routers by Arthur Dick Supervisor Anirban Mahanti.
Improving TCP Performance over Wireless Networks
SCTP: A new networking protocol for super-computing Mohammed Atiquzzaman Shaojian Fu Department of Computer Science University of Oklahoma.
Random Early Detection (RED) Router notifies source before congestion happens - just drop the packet (TCP will timeout and adjust its window) - could make.
Flow Control in Multimedia Communication Multimedia Systems and Standards S2 IF Telkom University.
Spring Computer Networks1 Congestion Control Sections 6.1 – 6.4 Outline Preliminaries Queuing Discipline Reacting to Congestion Avoiding Congestion.
Peer-to-Peer Networks 13 Internet – The Underlay Network
1 ICCCN 2003 Modelling TCP Reno with Spurious Timeouts in Wireless Mobile Environments Shaojian Fu School of Computer Science University of Oklahoma.
Instructor Materials Chapter 6: Quality of Service
Internet Networking recitation #9
Topics discussed in this section:
UNIT-V Transport Layer protocols for Ad Hoc Wireless Networks
Mohammad Malli Chadi Barakat, Walid Dabbous Alcatel meeting
Generalizing The Network Performance Interference Problem
Congestion Control and Resource Allocation
The Future of Transport
IT351: Mobile & Wireless Computing
Jiyong Park Seoul National University, Korea
Internet Networking recitation #10
Javad Ghaderi, Tianxiong Ji and R. Srikant
TCP Congestion Control
Congestion Control and Resource Allocation
Impact of transmission errors on TCP performance
Presentation transcript:

Efficient Internet Traffic Delivery over Wireless Networks Sandhya Sumathy

Introduction High Demand for Wireless Internet Connectivity Internet applications usually generate elastic traffic. e.g. Web, FTP, . Main objective for elastic traffic is minimization of the total file transmission time. Randomness is the basic characteristics of wireless communications

Overview of Internet Stack Architecture

Link Layer Optimizations for Elastic Traffic Packet Transmission Scheduling-increase throughput by exploiting the temporal fluctuations in Channel qualities. At any one time some users will enjoy better channel conditions. In order to increase user’s channel qualities packets are separated into buffers thus allowing a Scheduler to select an optimal user to transmit at any time. A scheduler will decide on the next queue to be serviced based on : Signal to noise ratio, Mean channel rate, Priority, Queue size.

Packet Transmission Scheduling continued.. Scheduling can be made optimal if buffers has packets queued and awaiting transmission. Scheduling can be made optimal if buffers has packets queued and awaiting transmission. Emptying a users packet at the base station leads to suboptimal scheduling. TCP flow control mechanism should not cause a buffer to drain and hold packets at the source.

Link Layer Rate Adaptation Incremental Redundancy (IR) Techniques vary the code rate on a transmission, tracking fluctuations in the channel quality. Link Adaptations (LA) Techniques measure the average channel quality and choose an appropriate modulation or coding scheme. The net effect : Time series of successful packet transmission time,as perceived by TCP flow control scheme is random and non stationary.

Transport Layer Objectives and adverse effects TCP is a window-based flow control algorithm. Its window size is minimum of congestion window (CWND) which is set by sender and the advertised window (AWND) set by receiver. Two dominant algorithms :Slow start and Congestion avoidance. In a wireless network the link rate is a random quantity which varies on distinct timescales.

Transport Layer Objectives and adverse effects continued… In order to keep the link buffer needs to be very large. TCP’s congestion control algorithm will attempt to fill this buffer. If the link rate drops suddenly excessively large latencies result. Small buffer will cause the link to be frequently starve for packets. This problem has been observed in recent studies of TCP’s performance over UMTS.

Proposed TCP Enhancements Recent proposals Sender-side modifications –changes to Sender-side modifications –changes to Internet Hosts. Internet Hosts. Performance enhancing proxies – affects Performance enhancing proxies – affects IP layer security, scalability IP layer security, scalability Receiver-side modifications –only require Receiver-side modifications –only require changes to wireless hosts. changes to wireless hosts. Explicit Window Adaptation –control TCP sender from receiving host by controlling the AWND feature. This is referred as receiver-side explicit window adaptation

Proposed TCP Enhancements continued.. An Algorithm CLAMP is recently proposed for receiver-side explicit window adaptation. An Algorithm CLAMP is recently proposed for receiver-side explicit window adaptation. This algorithm calculates a new AWND value taking into account the proximity factor, current rate of transfer etc. This algorithm tries to reduce the time that the link is left idle because of TCP holding packets at source.

Conclusion A flow control algorithm over wireless links should allow control over the trade-off between latency and utilization. Receiver-side flow control can be used to control existing TCP sources to reach desired objectives and increase the performance of wireless access to Internet. An algorithm such as CLAMP supplements TCP’s flow control mechanism.This can be used to ensure that lower-layer scheduling mechanisms can perform as intended. used to ensure that lower-layer scheduling mechanisms can perform as intended.

Questions?? Questions??

Thank You. Thank You.