[Παλιό]Throughput Stability and Flows in Large-Scale Random
Posted: Thu Jun 23, 2005 10:45 am
Ομιλία με θέμα "Throughput Stability and Flows in Large-Scale Random Networks"
Τρίτη 28 Ιουνίου, 4μ.μ., αίθουσα 709, Κτήριο Ευελπίδων.
Ομιλητές:
Χριστίνα Περάκη
Mεταπτυχιακή φοιτήτρια του πανεπιστημίου Cornell των Η.Π.Α.
Abstract:
This talk addresses the problem of determining the rate of growth of the maximum stable throughput achievable in dense wireless networks. The networks are modeled as random unit-disk graphs and the problem of throughput maximization under stability constraints is formulated as one of finding the maximum value of a multicommodity flow. First, a tight characterization of an optimal solution to the resulting linear program is provided using simple probability tools and flow techniques. Then, three different models of communication are considered: (a) omnidirectional transmissions; (b) "simple" directional transmissions, in which sending nodes generate a single beam aimed at a particular receiver; and (c) "complex" directional transmissions, in which sending nodes generate multiple beams aimed at multiple receivers. Only an increase in terms of logarithmic factors in maximum stable throughput is all that can be achieved by allowing arbitrarily complex signal processing (in the form of generation of directed beams) at the transmitters and receivers. We conclude, therefore, that neither directional antennas, nor the ability to communicate simultaneously with multiple nodes, can be expected in practice to effectively circumvent the constriction in capacity in dense networks that results from the geometric layout of nodes in space.
Christina Peraki received her Diploma in Electrical Engineering from the National Technical University of Athens in 2002. During her undergraduate studies she worked as a researcher on developing a metropolitan wireless network at the National Research Center in Greece at the Institute of Informatics and Telecommunications. Since 2002, she has been a research and teaching assistant in the Department of Electrical and Computer Engineering at Cornell University. Her research interests are in communication networks, wireless networks and network coding.
http://www.cs.aueb.gr/news/events/peraki.shtml
Τρίτη 28 Ιουνίου, 4μ.μ., αίθουσα 709, Κτήριο Ευελπίδων.
Ομιλητές:
Χριστίνα Περάκη
Mεταπτυχιακή φοιτήτρια του πανεπιστημίου Cornell των Η.Π.Α.
Abstract:
This talk addresses the problem of determining the rate of growth of the maximum stable throughput achievable in dense wireless networks. The networks are modeled as random unit-disk graphs and the problem of throughput maximization under stability constraints is formulated as one of finding the maximum value of a multicommodity flow. First, a tight characterization of an optimal solution to the resulting linear program is provided using simple probability tools and flow techniques. Then, three different models of communication are considered: (a) omnidirectional transmissions; (b) "simple" directional transmissions, in which sending nodes generate a single beam aimed at a particular receiver; and (c) "complex" directional transmissions, in which sending nodes generate multiple beams aimed at multiple receivers. Only an increase in terms of logarithmic factors in maximum stable throughput is all that can be achieved by allowing arbitrarily complex signal processing (in the form of generation of directed beams) at the transmitters and receivers. We conclude, therefore, that neither directional antennas, nor the ability to communicate simultaneously with multiple nodes, can be expected in practice to effectively circumvent the constriction in capacity in dense networks that results from the geometric layout of nodes in space.
Christina Peraki received her Diploma in Electrical Engineering from the National Technical University of Athens in 2002. During her undergraduate studies she worked as a researcher on developing a metropolitan wireless network at the National Research Center in Greece at the Institute of Informatics and Telecommunications. Since 2002, she has been a research and teaching assistant in the Department of Electrical and Computer Engineering at Cornell University. Her research interests are in communication networks, wireless networks and network coding.
http://www.cs.aueb.gr/news/events/peraki.shtml