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UNITN Research Unit Status of the Work – First Year

UNITN Research Unit Status of the Work – First Year. Fabrizio Granelli DIT – University of Trento granelli@dit.unitn.it. Ongoing activities. UNITN role in the project. Goal: “ Performance Enhancement of Wireless Mesh Networks and Testbed Implementation ” WP1 WP3 T3.4 Stream Control WP4

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UNITN Research Unit Status of the Work – First Year

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  1. UNITN Research Unit Status of the Work – First Year Fabrizio Granelli DIT – University of Trento granelli@dit.unitn.it “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  2. Ongoing activities 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, Jan. 19th, 2007

  3. Network Capacity Analysis: goal • To define and validate an analytical model for connectivity and capacity of Wireless Mesh Networks, given design parameters n,r, l. • Traffic from/to mesh base station ≠ ad-hoc scenario E. Miorando, F. Granelli, “On Connectivity and Capacity of Wireless Mesh Networks”, ICC 2007, accepted “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  4. Problem Statement n → # nodes (random distribution) S → squared area of dimension l x l m → # access points r → comm range nn → # neighbor nodes nf → # forwarding nodes “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  5. Problem Statement • Single-cell analysis • → squared area • → m = 1 • → interfering nodes • Traffic to/from BS • Hyp.:→ IEEE 802.11 CSMA/CA – RTS/CTS* • → MFR routing • → r = 250 [m] * → “Performance Analysis of the IEEE 802.11 Distributed Coordination Function”, by G. Bianchi (JSAC, March 2000) “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  6. Connectivity analysis No. offorwarding nodes* Poisson distribution: λ = nf * → “Optimal Transmission Ranges for Randomly Distributed Packet Radio Terminals”, by Takagi e Kleinrock (March 1984) “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  7. Connectivity analysis “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  8. Capacity analysis G G G G G G G G 1 2 3 4 5 6 7 8 G 2G 3G 4G 5G 6G 7G 8G • Bottleneck* • Bottleneck collision domain* * → “The Nominal Capacity of Wireless Mesh Networks”, by Jun e Sichitiu (Oct. 2003) “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  9. Capacity Analysis ni→ connected nodes at i-hops distance from the BS “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  10. Validation of the Approach • NS-2 simulator (v. 2.29) → C++ e OTcl • No WMN support → WiFi@11Mbps set tcp [new Agent/TCP] $tcp set class_ 2 set sink [new Agent/TCPSink] $ns_ attach-agent $node_(11) $tcp $ns_ attach-agent $node_(19) $sink $ns_ connect $tcp $sink set ftp [new Application/FTP] $ftp attach-agent $tcp $ns_ at 100.0 "$ftp start" “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  11. Experimental Results: pconn • Averaged on 50 runs • variable n l = 2500 r = 250 • Max error: 2,25 % • Avg. stdev: 8,15 % “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  12. Experimental Results: Capacity • Averaged on 50 runs • variable n l = 2500 r = 250 • Avg. error: 17,53 % • Avg. stdev: 22,85 % [kbit/sec] “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  13. Experimental Results: Capacity • Averaged on 20 runs • variable n l = 2500 r = 250 • Avg. error: 6,37 % • Avg. stdev: 17,55 % • Averaged on 20 runs • variable n l = 2500 r = 250 • Avg. error: 15,51 % • Avg. stdev: 22,15 % [kbit/sec] “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  14. Conclusions • A first model for connectivity and capacity of WMNs was developed and validated • Good accuracy • Points to consider: • Inter-cell interference • Heterogeneous WMN (e.g. WiMAX+WiFi) • Node movement (statistical model) “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  15. UNITN / CREATE-NET testbed “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  16. Testbed: where are we? • Started from Roofnet, making it device-agnostic: • Monitor mode  ad hoc mode • Link quality evaluation using ETX • Roofnet on laptops works! • Roofnet patch available on WOMEN website “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  17. Testbed: where are we? • Software porting to openwrt successful • Automatic Gateway Discovery working • Meraki (Roofnet spin-off) openwrt platform freely available • Click in userspace running on 200MHz CPUs • 802.11 working in b mode “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  18. 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, Jan. 19th, 2007

  19. 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, Jan. 19th, 2007

  20. SCHEDULER prototypes • First prototype - COMPLETED: • Priority scheduling based (WRR) • Works for TCP/UDP (2 hops test) • Second prototype – WORK IN PROGRESS: • TRADE-OFF UTILIZATION/FAIRNESS • Priority scheduling based (WRR) • RED queuing policies (avoid drop-tail) ? • Fairness idea: use deficit queues (one for each service class) which provides FQ fairness • Channel awareness ? • Channel measurements -> long implementation • proper temporal scale to avoid fading and multipath phenomena “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  21. Measurement platform (completed) • Set of bash scripts for: • Automatic ssh key distribution among nodes • Tcp and udp bi-directional distributed measurements (iperf) • Throughput • Jitter • delay • Results collection and post-processing • Can launch arbitrary unix commands on remote nodes “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  22. Dissemination activities - Papers • E. Miorando, and F. Granelli"On Connectivity and Capacity of Wireless Mesh Networks,“IEEE International Conference on Communications (ICC’07), Glasgow, Scotland, June 2007 (accepted). • D. Kliazovich, F. Granelli and D. Miorandi“Logarithmic Window Increase for TCP Westwood+ Improvement in High Speed, Long Distance Networks,”Computer Networks (submitted). “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  23. UNITN Research UnitFuture Activities Fabrizio Granelli DIT – University of Trento granelli@dit.unitn.it “WOMEN” Project Meeting Rome, Jan. 19th, 2007

  24. Activities in the 2nd Year • Finalization of Network Capacity Analysis • Testbed Design: • Partially @CreateNet, partially @UniTN + WiMAX-like long distance link • Frequency allocation @UniTN • Testbed Implementation: • Second prototype design and programming • Testbed deployment • Tests on testbed • Results collection and analysis “WOMEN” Project Meeting Rome, Jan. 19th, 2007

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