MATC Fall Lecture Series: Hamid Sharif
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MATC Fall Lecture Series: Hamid Sharif

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MATC Fall 2012 Lecture Series

MATC Fall 2012 Lecture Series

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  • For these you need to point out that the simulation uses the actual test bed layout, instead of the abstracted 1000m spacing!
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MATC Fall Lecture Series: Hamid Sharif MATC Fall Lecture Series: Hamid Sharif Presentation Transcript

  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING State of Wireless Communications in North American Freight Railroads Hamid Sharif Computer and Electronics Engineering Department Advanced Telecommunications Engineering Laboratory (TEL) University of Nebraska – Lincoln September 28, 2012 Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Wireless in Railroads• The Five-Year US Federal Railroad Administration (FRA) Strategic Plan for Railroad Research and Development identifies mobile wireless communication as one of the most critical areas to collect, process, and disseminate information to improve the safety, security, and operational effectiveness of railroads. * * From: The vision for the future of intelligent railroad systems Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING State of Wireless in Railroads• Voice – Portions of the voice wireless infrastructure are more than 30+ years old.• Data – The Advanced Train Control System (ATCS) wireless data networks (developed in 80s) are only supporting at best 4800/9600 bps and not designed to support today’s multimedia and Internet type applications. Advanced Telecommunications Engineering Laboratory (TEL) View slide
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Project’s Objectives• Study the suitable wireless technology for current and future of mobile railroads to support: – high-speed data network for moving trains – real-time Internet accessibility for trains’ crews, passengers, and ground crews – improving railroad operating safety and effective operations Advanced Telecommunications Engineering Laboratory (TEL) View slide
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Industry Partners• Federal Railroad Administration (FRA)• American Association of Railroad (AAR)• Freight Railroads of North America: – Union Pacific Railroad – BNSF Railway – CSX Transportation – Norfolk Southern Railway – Canadian National Railway – Canadian Pacific Railway Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Research Methodology• Build comprehensive simulation models to complement our theoretical study for wireless standard protocols.• Testbed experiments to study and evaluate the implementation of these technologies for the railroad environments. Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERINGPHASE 1 - WIFI Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Overview of WiFi Project Phase• Feasibility of WiFi in mobile railroad environment• Performance evaluations of WiFi throughput in mobile railroad scenarios• Study of handoff and Quality of Service (QoS) in WiFi for mobile railroad applications• Performance evaluations of multimedia applications over WiFi in railroad environments Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Theoretical Approach• Investigation of the mobility impact on performance of the 802.11x system with fading under different client velocities• Analysis of the impact of Doppler shift caused by the velocity of transmitter and receiver• The multipath interference due to reflections and diffractions from terrain and objects in the radio coverage area and other serious impairment factors• Study of the bit error rate performances for various velocities with different data rates Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Simulation Models• 802.11x features designed and implemented:• PHY: – Determines the impact of noise, fading and Doppler shift – Calculates effects of shadowing, Rician and Rayleigh fading• MAC: – Fragmentation and Defragmentation, Data Retransmission – Multirate support (fixed as well as rate adaptation) – Multiple channels, Channel scanning – Synchronization, Power management – Authentication, Association, Re-Association, Handoff Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING WiFi Test bed• A 3.5 mile section of BNSF track at Crete Nebraska was chosen for it’s close proximity to the UNL, low traffic volumes, and challenging environment (heavy foliage, curves, surrounding hills).• Test bed utilizes the 802.11 technology to support wireless connectivity between moving trains and fixed Access Points.• Involved with the design of Testbed were: AAR, BNSF, UP, CSX and CN Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Test Bed BNSF Core Network Router/Gateway Router/Gateway BNSF WAN VPN into CC BNSF WAN Internet Microwave Link DSL Link Microwave Microwave NC NC CC NC CC NC CC NC CC NC CC NC CC NC CC AP8 AP7 AP6 AP5 AP4 AP3 AP2 AP1Crete Depot Berks East Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Test Bed Area Map Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING WifiTools Features• GPS with real-time mapping – GPS integrated into user interface – Retrieves current location in test bed from GPS device, displays location of test client and all APs in test bed, calculates distances to all APs and records all information• WifiPoll with real-time plotting – WifiPoll measures all Wifi adapter information, such as link speed and status, signal strength, channel, current associated AP, throughput, etc. – Real-time plotting of these results allows real-time evaluation of testing progress – Graphs include: Tput vs. Time, Tput vs. Distance, Tput histogram, RSSI (signal strength) vs. Time, RSSI vs. Distance, RSSI histogram, AP association vs. Time Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Developed test tools (WifiViz) Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Antenna Field Pattern Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Comparison of Test Bed Results and Simulation Comparison of Field Test Results and Simulation Results using GPS Log Information 7000 6000 5000Throughput (kbps) 4000 3000 2000 1000 0 12:21:01 12:23:54 12:26:47 12:29:40 12:32:33 12:35:25 12:38:18 12:41:11 Time Field Test 04/27/2006 Simulation using GPSLog Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Mobility test results Throughput vs. Time 7 Throughput 6 Throughput (Mbps) 5 4 3 2 1 0 10:33:36 11:45:36 12:57:36 14:09:36 15:21:36 Time Velocity vs Time 70 Velocity 60 50 Velocity (mph) 40 30 20 10 0 10:33:36 11:45:36 12:57:36 14:09:36 15:21:36 Time Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERINGThroughput vs. Distance Comparisons Throughput vs Distance Comparison - 802.11b 1 Mbps 1000 900 800 700 Throughput (kbps) 600 NS-2 Qualnet 500 Theory 400 Field Cutoff 300 200 100 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Distance (meters) Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Summary of Findings• Benefits of WiFi: – Operates in unlicensed frequency band, easily accessible for railroads – Good network throughput (about 6 Mbps in good channel) – Supports mobility (tested up to 70 mph) – Inexpensive and readily available equipment and setups – Supports real time multimedia applications• Drawbacks of WiFi: – Communication Distance limited to only a mile (under excellent LOS conditions only) – Limited number of channels in unlicensed band creates competition among all WiFi networks in an area • Interference becomes a problem – Contention-based multiuser access scheme creates problems for coexistence – No Quality-of-Service mechanism for multimedia applications – No standardized approach for interconnecting WiFi access points Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERINGPHASE 2 – MOBILE WIMAX Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Mobile WiMAX - Overview• Is designed to be a 4G network technology – All-IP network infrastructure, based on IEEE 802.16e • 802.16e/802.16-2007 is air interface only • Mobile WiMAX defines end-to-end system – Supports large communication distances • Initial target distance for Mobile WiMAX was 30 miles – Supports high throughput • 20 MHz channel provides up to 70 Mbps throughput – Supports mobility • Mobile nodes are supported even at 120 mph – Supports QoS and streaming applications • Mobile WiMAX has robust QoS for video and voice applications over wireless channels Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Mobile WiMAX – RF Frequency Space• UNL has 5 EBS licenses, centered around Omaha, Lincoln, Kearney (35 miles radius), among them: WCG671 – around Lincoln WHR724 – around Omaha Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Mobile WiMAX Simulation Model Results from Lab Testing and Computer Simulations Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING WiMAX Simulation Model ComparisonFeatures QualNet 4.0 OPNet NS-2 Models: Taiwan Italy NIST TEL (our model)Air Interface 802.16e 802.16e 802.16-2004 802.16d 802.16e 802.16-2009Duplex TDD n/a TDD n/a TDD TDDPHY Mode OFDMA OFDMA OFDMA n/a OFDM OFDM, OFDMAARQ, Hybrid-ARQ Y, N Y, N N, Y N, N N, N Y, YMultihop Backhaul n/a n/a N Y N YQoS Y Y Y N N I/PFlow Scheduling Y Y Y N N YAMC Support n/a n/a N n/a N YMode Pt-to-MPt n/a Pt-to-MPt Mesh Pt-to-MPt Pt-to-MPtRealistic RF model n/a n/a N n/a N YMobility Support Y Y N N Y YHandoff Schemes Y Y, limited n/a n/a Y YMultimedia Support n/a n/a N n/a N YDevice Emulation n/a n/a N n/a N YASN-GW Support N n/a N N N I/P Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Mobile WiMAX Simulation Results Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Comparison of Theory, Simulation, Tests Total Throughput for Simulation, Lab-Test, and Theory 25000 20000 15000Throughput (kbps) 10000 5000 0 qpsk-1/2 qpsk-3/4 16qam-1/2 16qam-3/4 64qam-2/3 64qam-3/4 Simu-wimax Test-pBst Theory Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Predicted Distance for Test Equipment Mobile WiMAX Throughput vs Distance 18000 16000 14000 12000Throughput (kbps) 64QAM34 DL 10000 64QAM23 DL 8000 16QAM34 DL 16QAM12 DL 6000 QPSK34 DL QPSK12 DL 4000 2000 0 0 2000 4000 6000 8000 10000 12000 14000 Distance (meters) Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERINGSample Simulation Scenarios we are studying Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Event Recorder Data Upload Key Parameters: • 70 mph train speed • 5 km AP Spacing (~3.1 miles) • Total length of 20 km • Uses maximum data transfer rate Event Recorder UL - Throughput Event Recorder UL – File Size 6000 4.5 140 4.5 4 120 4 5000Data Throughput (kbps) 3.5 3.5 100 FileSize (Mbyte) 4000 3 3 2.5 80 2.5 AP ID AP ID 3000 2 60 2 2000 1.5 1.5 40 1 1 1000 20 0.5 0.5 0 0 0 0 0 50 100 150 200 250 0 50 100 150 200 250 Time (s) Time (s) TCP Throughput AP Association FTPFileSize AP Association Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Video Streaming Fairness ComparisonFairness Impact on Image Quality Fairness Impact on Throughput Throughput Fairness vs. Total Station Number 1 1 0.95 0.95 0.9 0.9 Throughput Fairness Index 0.85 0.85PSNR Fairness Index 0.8 0.8 0.75 0.75 0.7 0.7 0.65 0.65 0.6 0.6 0.55 802.16 0.55 802.16 802.11 802.11 0.5 0.5 0 2 4 6 8 10 12 14 16 0 2 4 6 8 10 12 14 16 Total Station Number Total Station Number Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Mobile WiMAX Video: PKI NeighborhoodDrive around the new Aksarben Neighborhood: Distance to PKI is about 0.5 miles Several signal obstructions from buildings in the area. This is all done under the coverage of a SINGLE WiMAX Base Station! Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Mobile WiMAX Video: ParkDrive around Elmwood Park: Distance to PKI is about 0.4 miles at farthest point Extreme signal obstruction and scattering from trees in park! WiFi would fail after the first few yards into the park area! Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERINGMobile WiMAX Video: Speed and DistanceDrive on West Center road: Distance to PKI is between 0.6 miles and 1.0 miles at end! Signal obstructions from buildings between road and PKI, Doppler shift from 60 mph! Under the coverage of a SINGLE WiMAX Base Station, with LOS RSSI=-66dBm at 1 mile! Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERINGMultiuser Comparison – WiFi and WiMAX• WiMAX exhibits more efficiency (less overhead) Total Throughput vs. No. of Subscribers Uplink Performance under N STAs 13 – WiFi degrades with increased 12 no. of subscribers 11 – Outcome of contention-based 10 operation in WiFi Throughput(Mbps) 9 – Central resource 802.11 802.16 8 management eliminates these issues for 7 downlink, drastically reduces 6 its impact for uplink 5• WiMAX also demonstrates 4 0 2 4 6 8 Station Number 10 12 14 16 better fairness among multiple subscribers Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Mobile WiMAX Field Tests Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Field Tests - Overview• Field tests designed to provide real-world performance data – Maximum communication distance – Maximum throughput at different velocities – Handover performance with and w/o ASN-GW – Latency, Packet Loss, Quality-of-Service, etc.• We are utilizing microwave tower sites made available to us by Union Pacific and BNSF• Preliminary Field Tests have been performed around our campus Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Test Site 1 – UP: Logan, IA Road for WiMAX Tests 120degree coverage area of antenna (shaded area) Main Antenna Direction Indicator Logan, IA - Tower 3 miles (approx.) Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Test Site 2 – BNSF: Ashland, NE Road for WiMAX Tests Ashland, NE - Tower Main Antenna Direction Indicator 120degree coverage area of antenna (shaded area) 3 miles (approx.) Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Summary• High-speed data networks is critical for effective railroad operations in mobile environments.• One technology may not be the solution for all railroad needs.• Combination of WiFi and WiMAX is a promising solution.• An integrated solution is needed to support audio and video (multimedia type) applications. Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Advanced Telecommunications Engineering Laboratory (TEL)
  • UNIVERSITY OF NEBRASKA – LINCOLN COLLEGE OF ENGINEERING Contact Information• Hamid Sharif• Email: hsharif@unl.edu• Phone: (402) 554-3628• Web: www.tel.unl.edu• Thank you! Advanced Telecommunications Engineering Laboratory (TEL)