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UNC/FORTH Archive of Wireless Traces, Models and Tools. Prof. Maria Papadopouli 1,2. 1 Foundation for Research & Technology-Hellas (FORTH) & University of Crete 2 University of North Carolina at Chapel Hill. IBM Faculty Award , EU Marie Curie IRG, GSRT grants. Wireless landscape.
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UNC/FORTH Archive of Wireless Traces, Models and Tools Prof. Maria Papadopouli1,2 1Foundation for Research & Technology-Hellas (FORTH) & University of Crete 2 University of North Carolina at Chapel Hill IBM Faculty Award, EU Marie Curie IRG, GSRT grants
Wireless landscape • Growing demand for wireless access • Mechanisms for better than best-effort service provision Admission control, channel switching, load balancing, roaming • Performance analysis of these mechanisms • Majority of studies make high-level observations about traffic dynamics in tempo-spatial domain • Models of network &user activityin various spatio-temporalscales are required • Limited studies and testbeds for DTNs
User B Wireless infrastructure disconnection Internet Router Wired Network AP3 Switch Wireless Network User A AP 1 AP 2
1 2 3 0 Wireless infrastructure Internet disconnection Router Wired Network Switch AP3 Wireless Network User A AP 1 AP 2 roaming roaming User B Associations Flows Packets
Modelling objectives • Important dimensions on wireless network modelling • user demand (access & traffic) • topology (network, infrastructure, radio propagation) • Structures that are well-behaved, robust, scalable & reusable • Publicly available analysis tools, traces, & models
Internet disconnection Wired Network Router Switch AP3 Wireless Network User A AP 1 AP 2 Events User B Session 1 2 3 0 Association Flow Arrivals t1 t2 t3 t4 t5 t6 t7 time
Modeling structures • Session • arrival process • starting AP • Flow within session • arrival process • number of flows • size Captures interaction between clients & network Above packet level for traffic analysis & closed-loop traffic generation
Tradeoffs in spatio-temporal modeling Objective Scale
Summary of modeling results Multi-level parametric modelling of wireless demand • Network-wide models: • Time-varying Poisson process for session arrivals • biPareto for in-session flow numbers & flow sizes • Lognormal for in-session flow interarrivals • Validation of models over two different periods • Same distributions apply for modeling at finer spatial scales building-level, groups of buildings with similar usage • Evaluation of scalability-accuracy tradeoff
UNC/FORTH web archive Online repository of models, tools, and traces • Packet header, SNMP, SYSLOG, signal quality http://netserver.ics.forth.gr/datatraces/ Free login/ password to access it Joint effort of Mobile Computing Groups @FORTH & UNC maria@csd.uoc.gr