Broadband Wireless Network Applications and Performance

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Broadband Wireless Network Applications and
Performance

• Carey Williamson
• Professor/iCORE Senior Research Fellow
• Department of Computer Science
• University of Calgary

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Background Information

• Education
• B.Sc.(Hon.), Computer Science, U.Sask., 1985
• Ph.D., Computer Science, Stanford U., 1992
• Experience
• Dept of Computer Science, U.Sask., 1991-2001
• Adjunct Scientist, TRLabs Saskatoon, 1991-2001
• Research Areas
• Computer Networks, Performance Evaluation
• Professional Service/Memberships
• ACM (SIGMETRICS, SIGCOMM), IEEE, SCS

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Internet Protocol Stack

• Application supporting network applications and
  end-user services
• FTP, SMTP, HTTP, DNS, NTP
• Transport end to end data transfer
• TCP, UDP
• Network routing of datagrams from source to
  destination
• IPv4, IPv6, BGP, RIP, routing protocols
• Data Link hop by hop frames, channel access,
  flow/error control
• PPP, Ethernet, IEEE 802.11b
• Physical raw transmission of bits

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Research Interests

• Network Traffic Measurement
• Workload Characterization
• Traffic Modeling
• Network Simulation
• Web Performance
• Adaptive Network Applications

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Network Traffic Measurement

• Collect and analyze packet-level traces from a
  live network

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Network Traffic Measurement

• Collect and analyze packet-level traces from a
  live network, using special equipment

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Network Traffic Measurement

• Collect and analyze packet-level traces from a
  live network, using special equipment

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Network Traffic Measurement

• Collect and analyze packet-level traces from a
  live network, using special equipment
• Process traces, statistical analysis
• Diagnose performance problems (network,
  protocol, application)

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Workload Characterization

• Try to understand the salient features of
  network, protocol, application, and user
  behaviour on the Internet
• Example Web server workloads Arlitt96
• Zipf-like document referencing behaviour
• Lots of one-time referencing of documents
• Heavy-tailed file size distributions
• Self-similar network traffic profile

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Traffic Modeling

• Construct programs and statistical models that
  capture the empirically-observed network traffic
  behaviours
• Allows flexible, controlled, repeatable
  generation of workloads for experiments
• Examples
• Web client workload model
• MPEG compressed video model
• Self-similar Ethernet LAN traffic model
• Synthetic Web proxy workload generator

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Network Simulation

• Use computer simulation to study the packet-level
  behaviour of the Internet, its protocols, its
  applications, and its users
• Examples
• Improving Web performance over ADSL
• Understanding the effects of user mobility on
  Mobile IP routing and protocol performance
• Studying the design, scalability, and performance
  of Web server and Web proxy caching architectures

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Web Performance

• Explore techniques to improve the performance and
  scalability of the Web
• Examples
• Clustered Web servers
• Load balancing policies
• Web prefetching strategies
• Web proxy caching architectures
• Improvements to HTTP and TCP protocols

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Adaptive Network Applications

• Explore design of Internet-based network
  applications (or protocols) that can adapt their
  behaviour (automatically) to make appropriate use
  of available resources
• Examples
• Web content for Java-enabled phones
• Multicast support for mobile users
• Location-aware routing optimizations
• Wireless-aware TCP protocol
• File system support for mobile users

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Summary of Research Plan

• Broadband Wireless Networks Lab (UofC)
• Experimental Laboratory for Internet Systems and
  Applications (UofS/UofC,CFI)
• Research Team
• Four full-time research staff (Web, perf. eval.,
  simulation, wireless, traffic modeling, network
  measurement) plus 6-10 graduate students
• Research Collaborations
• UofC, UofA, UofS, TRLabs, CS/ECE
• Nortel? HP? Cisco? Agilent? Compaq? Others?
• Do cool, hands on, industrially-relevant,
  applied, practical, and exciting stuff!!