1 / 28

Cross Layer Optimization Techniques

Cross Layer Optimization Techniques. Department of Electrical Engineering & Computer Science EECS 983 Class Project Ramya Naidu Sarvesh Kumar.V Asifuddin Mohammad Piyush Upadhyay. 9 May 2008. Cross Layer Optimization Techniques Outline. Introduction UDP segment Size adaptation

elise
Download Presentation

Cross Layer Optimization Techniques

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cross Layer Optimization Techniques Department of Electrical Engineering & Computer Science EECS 983 Class Project Ramya Naidu Sarvesh Kumar.V Asifuddin Mohammad Piyush Upadhyay 9 May 2008

  2. Cross Layer Optimization TechniquesOutline • Introduction • UDP segment Size adaptation • Knobs and Dials Simulation Framework • TCP segment size adaptation • Issues • Effect of ARQ on TCP performance • Effect of FEC/ARQ on TCP performance 9 May 2008 Cross Layer Optimization Techniques 2

  3. Cross Layer Optimization TechniquesIntroduction • Cross Layer Optimization [CLO]: • An approach that coordinates protocol behavior at different layers with a goal to maximize the overall performance [4] • Knobs and Dials • Dials pass information from lower to higher layer • Knobs pass info from higher to lower layer • CLO Technique considered: • Transport layer with Physical Layer interaction • Segment size with BER 9 May 2008 Cross Layer Optimization Techniques 3

  4. Cross Layer Optimization TechniquesOutline • Introduction • UDP segment Size adaptation • Knobs and Dials simulation framework • TCP segment size adaptation • Issues • Effect of ARQ on TCP performance • Effect of ARQ/FEC on TCP performance • Hardware Implementation 9 May 2008 Cross Layer Optimization Techniques 4

  5. Cross Layer Optimization TechniquesUDP Segment Size adaptation • Adapt UDP segment size as BER of the link changes • Initial Analysis of effect on throughput • Simulation parameters • Number of nodes 2 • CBR/UDP • Rate 1Mbps • Link Capacity 1Mbps • Simulation time 50s • Error Model Uniform 9 May 2008 Cross Layer Optimization Techniques 5

  6. Cross Layer Optimization TechniquesUDP Segment Size adaptation 9 May 2008 Cross Layer Optimization Techniques 6

  7. Cross Layer Optimization TechniquesUDP Segment Size adaptation • Initial Analysis with UDP lead to two directions • Building the knobs and dials simulation framework • Study the complications when extending this scheme to TCP 9 May 2008 Cross Layer Optimization Techniques

  8. Cross Layer Optimization TechniquesOutline • Introduction • UDP segment Size adaptation • Knobs and Dials Simulation Framework • TCP segment size adaptation • Issues • Effect of ARQ on TCP performance • Effect of ARQ/FEC on TCP performance • Hardware Implementation 9 May 2008 Cross Layer Optimization Techniques 8

  9. Knobs and Dials Simulation Framework

  10. Cross Layer Optimization Techniques Knobs and Dials Simulation Framework • Step 1: Node 1 Sends packets to Node 2

  11. Cross Layer Optimization Techniques Knobs and Dials Simulation Framework • Step 2: Computer BER from received packets and update the dial matrix

  12. Cross Layer Optimization Techniques Knobs and Dials Simulation Framework • Step 3: Write the BER from dial matrix to the dial packet (Out of band signaling)

  13. Cross Layer Optimization Techniques Knobs and Dials Simulation Framework • Dial Packet format used • Choice of Inband Vs Out of band signalling has to be made • Dial Packet format should be decided if out of band signaling is used

  14. Cross Layer Optimization Techniques Knobs and Dials Simulation Framework • Step 4: Read the BER value from the dial packet and write it to the dial matrix of node 1

  15. Cross Layer Optimization Techniques Knobs and Dials Simulation Framework • Step 5: Read the BER value from the dial matrix of N1 and compute the new segment size

  16. Cross Layer Optimization Techniques Knobs and Dials Simulation Framework • Step 6: Write the new segment size to the knob matrix (An unused knob) and transmit with this size

  17. Cross Layer Optimization Techniques Simulation Challenges • Creating a new signaling protocol for out of band signaling <solved> • Building knob and dial hashes at each node <solved> • Accessing packet headers <solved> • Obtaining a Tcl handle to C++ class variables to enable per packet processing <solved> • Per packet processing <Yet to be solved>

  18. Cross Layer Optimization Techniques Knobs and Dials Simulation Framework • Issues to be addressed: • Complexity at each node • Overhead due to extra signaling (Out of band) • Loss of Signaling packets • RTT of the link • Changes to framework in case of multi-hop network with multiple interfaces at nodes

  19. Cross Layer Optimization TechniquesOutline • Introduction • UDP segment Size adaptation • Knobs and Dials Simulation Framework • TCP segment size adaptation • Issues • Effect of ARQ on TCP performance • Effect of ARQ/FEC on TCP performance • Hardware Implementation 9 May 2008 Cross Layer Optimization Techniques 19

  20. Cross Layer Optimization TechniquesTCP Segment Size adaptation • TCP with Link layer reliability • Effect of ARQ on TCP • Effect of FEC/ARQ on TCP • TCP without Link layer reliability 9 May 2008 Cross Layer Optimization Techniques 20

  21. Cross Layer Optimization TechniquesEffect of ARQ on TCP • ARQ persistency and TCP RTO • ARQ with low persistency does not improve TCP throughput • High persistency improves TCP performance [2] • Problems of ARQ with high persistency [1] 9 May 2008 Cross Layer Optimization Techniques 21

  22. Cross Layer Optimization Techniques Effect of ARQ/FEC on TCP • Throughput improvement is more significant due to ARQ than due to FEC in an ARQ/FEC scheme [2] 9 May 2008 Cross Layer Optimization Techniques 22

  23. Cross Layer Optimization TechniquesTCP without link layer reliability • LL retransmission does not always improve TCP throughput [1] • This motivates the study of segment size adaptation 9 May 2008 Cross Layer Optimization Techniques 23

  24. Cross Layer Optimization Techniques Simulation Challenges • Implementing FEC in ns2 < Yet to be solved > • Hacking the ns2 error model code<Yet to be solved>

  25. Cross Layer Optimization Techniques Future Work • Extending the simulations to multi-hop scenarios • Study the impacts of cross-layering signaling • Extending the framework for other knobs and dials

  26. Cross Layer Optimization TechniquesOutline • Introduction • UDP segment Size adaptation • TCP segment size adaptation • Issues • Effect of ARQ on TCP performance • Effect of ARQ/FEC on TCP performance • Hardware Implementation 9 May 2008 Cross Layer Optimization Techniques 26

  27. References • [1] Kim Hyogon, Changhoon Han. "Reducing TCP response time in face of wireless uplink losses." IEEE VTC'01 1(2001): 262-266. • [2] A.Chockalingam, Michael Zorzi. "Wireless TCP Performance with Link Layer FEC/ARQ." IEEE ICC'99 2(1999): 1212-1216. • [3] Jin-Hee Choi, Jin-Ghoo Choi,Chuck Yoo. "Dynamic Segment Size Adjustment for TCP performance in cellular networks." ICEE'05 (2005): 95-96. • [4] A.Warrier,L.Le and I.Rhee. “Cross-Layer Optimization made practical”. Broadnets 2007(Invited paper) • [5] Gary J. Minden, Joseph B. Evans, Leon Searl, Daniel DePardo, Victor R. Petty, Rakesh Rajbanshi, Jordan Guffey, Qi Chen, Timothy Newman, Frederick Weidling, Dinesh Datla, Brett Barker, Megan Peck, Brian Cordill, Alexander M. Wyglinski, and Arvin Agah, “KUAR: A Flexible Software-Defined Radio Development Platform,” Second IEEE Symposium on New Frontiers in Dynamic Spectrum Access Networks (Dublin, Ireland), April 2007. 9 May 2008 Cross Layer Optimization Techniques 27

  28. References • [6]Minden, G.J.   Evans, J.B.   Searl, L.S.   DePardo, D.   Rajbanshi, R.   Guffey, J.   Qi Chen   Newman, T.R.   Petty, V.R.   Weidling, F.   Peck, M.   Cordill, B.   Datla, D.   Barker, B.   Agah, A. ” COGNITIVE RADIOS FOR DYNAMIC SPECTRUM ACCESS - An Agile Radio for Wireless Innovation” IEEE communication Magazine, May 2005, Vol. 45,issue 5. 9 May 2008 Cross Layer Optimization Techniques

More Related