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UNITN Research Unit Status of the Work. Fabrizio Granelli DIT – University of Trento granelli@dit.unitn.it. UNITN role in the project. Goal: “ Performance Enhancement of Wireless Mesh Networks and Testbed Implementation ” WP1 WP3 T3.4 Stream Control WP4 T4.5 Network Capacity Analysis
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UNITN Research Unit Status of the Work Fabrizio Granelli DIT – University of Trento granelli@dit.unitn.it “WOMEN” Project Meeting Rome, Sept. 8th, 2006
UNITN role in the project • Goal: “Performance Enhancement of Wireless Mesh Networks and Testbed Implementation” • WP1 • WP3 • T3.4 Stream Control • WP4 • T4.5 Network Capacity Analysis • WP5 (Resp.) • T5.6 (Testbed) (Resp.) • T5.7 (Trials) (Resp.) “WOMEN” Project Meeting Rome, Sept. 8th, 2006
UNITN activities (Phase I) • T1.1 “User and Application Requirements” • T1.2 “WOMEN System Definition” • T1.3 “WOMEN System Refinement” • T3.4 “Stream Control” (M3-M6) • TCP Performance on Heterogeneous Networks • Cross-layering Design for Improving Network Performance “WOMEN” Project Meeting Rome, Sept. 8th, 2006
TCP Performance Enhancement:TCP LogWestwood+ • Design Objectives • To be more aggressive than Standard TCP to guarantee equal or better throughput and utilization • Fast increase for low window values while accurately approach the available pipe capacity • Small sensitivity with respect to RTT • TCP LogWestwood+ combines smart TCP Westwood window decrease with Logarithmic increase function Ref.: D. Kliazovich, F. Granelli, and D. Miorandi, "TCP Westwood+ Enhancements for High-Speed Long-Distance Networks,“ ICC'06. “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Window Control during congestion avoidance Wmax – window size before the last packet loss occurred TCP LogWestwood+ Logarithmic Linear AIMD (Standard TCP) On packet loss (3 dup ACKs) = * 2, if W < Wmax = / 2, if W ≥ Wmax ≥ 2 (initial value) “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Window Evolution TCP LogWestwood+:Performance Total Capacity (+Buffers) Physical Capacity Total Capacity 2 “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Error-prone Bottleneck link TCP LogWestwood+:Performance • Single-flow • Multi-flow “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Quantifying Cross-layer Design • Quantifying the effect of potential cross-layer interactions is very important • to systematically relate such interactions to system outcomes • to quantify the decision to take such interactions into account • We propose to quantify cross layer interactions by defining factors (parameters) and effects (measurements) across layers • in a way that is common in system science and operations research Ref.: F. Granelli, M. Devetsikiotis, “Designing Cross-Layering Solutions for Wireless Networks: a General Framework and Its Application to a Voice-over-WiFi Scenario,” CAMAD 2006. “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Quantifying Cross-layer Design • Cross-Layer Sensitivity and Performance Optimization “WOMEN” Project Meeting Rome, Sept. 8th, 2006
UNITN / CREATE-NET testbed “WOMEN” Project Meeting Rome, Sept. 8th, 2006
IPv4 IPv6 IPX Mesh connectivity Layer with LQSR Ethernet 802.11 802.16 UNITN / CREATE-NET testbed • preWiMAX link (Alvarion BreezeAccess) • IEEE 802.11a PHY • Currently operative • Finished testing MSR MCL software (lab) • Decided to start from RoofNet • Open source • More documentation “WOMEN” Project Meeting Rome, Sept. 8th, 2006
RoofNet Main Features: • Wireless Mesh Networking SW developed by MIT (based on Click Modular Router architecture) • Multi-hop transmission • Optimized routing using a specific metric Limitations: • Need for WiFi cards with Atheros chipset • Madwifi driver Goal: • To port RoofNet to any hw/sw platform “WOMEN” Project Meeting Rome, Sept. 8th, 2006
RoofNet Why dedicated HW? • Probe transmission for link quality measurements in broadcast mode at arbitrary rate • BSSID partitioning • Routing metric is calculated by ETT ETT = ETX * S/B (S=data size, B=used bandwidth) Problem: • IEEE 802.11 does not enable arbitrary rate in broadcast signalling “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Packet preamble Roofnet strategy: • Monitor mode (not IEEE 802.11 standard) • MadWiFi driver for “raw” 802.11 frames and to control preamble information “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Preamble management in Click Click modules: • Read RSSI, noise, bitrate, etc. from incoming packet • Translate ingoing IEEE 802.11 packet into a Ethernet frame • Set rate and transmission power of the outgoing packet “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Roofnet Modifications • Change from monitor mode to ad-hoc mode (supported by any IEEE 802.11 NIC) • Introduction of an element for static setting of preamble parameters • link-quality evaluation using ETX “BlankDecap” module settings flags = 0; power = 60; rssi = 8; rate = 2; retries = 0; “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Open Issues • It is not possible to send probes in broadcast mode at arbitrary rates maybe unicast? • We changed link quality evaluation from ETT to ETX model • Problem with chipsets non allowing MTUs > 1500 bytes (e.g. Intel Centrino) • Installation to Linux-enabled APs • To make Roofnet patch available on the web “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Dissemination activities - Project • 11th Intenational Workshop on Computer-Aided Modeling, Analysis and Design of Communication Links and Networks (CAMAD 2006, Trento, June 8-9, 2006) • WOMEN leaflet • CAMAD’06 website, dinner ticket • Contribution to organization “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Dissemination activities - Papers • D. Kliazovich, F. Granelli, G. Pau, and M. Gerla"APOHN: Subnetwork Layering to Improve TCP Performance over Heterogeneous Paths,“IEEE Next Generation Internet Design and Engineering (NGI), Valencia, Spain, April 2006. • D. Kliazovich, F. Granelli, and D. Miorandi"TCP Westwood+ Enhancements for High-Speed Long-Distance Networks,“IEEE International Conference on Communications (ICC'06), Istanbul, Turkey, June 2006. • F. Granelli, M. Devetsikiotis“Designing Cross-Layering Solutions for Wireless Networks: a General Framework and Its Application to a Voice-over-WiFi Scenario,” CAMAD 2006, June 8-9, 2006, pp. 1-7. “WOMEN” Project Meeting Rome, Sept. 8th, 2006
UNITN estimated budget “WOMEN” Project Meeting Rome, Sept. 8th, 2006
UNITN consumed budget “WOMEN” Project Meeting Rome, Sept. 8th, 2006
UNITN Research UnitFuture Activities Fabrizio Granelli DIT – University of Trento granelli@dit.unitn.it “WOMEN” Project Meeting Rome, Sept. 8th, 2006
Activities in the next period • WMesh capacity evaluation • Analytical + simulation • Finalize SW package for Roofnet porting • Start SW installation of mesh-enabled IEEE 802.11 APs • Start planning the physical deployment of the network “WOMEN” Project Meeting Rome, Sept. 8th, 2006
UNITN available budget “WOMEN” Project Meeting Rome, Sept. 8th, 2006