Tadeusz CzachorskiProfessor, Institute of Theoretical and Applied Informatics, Polish Academy of Sciences, Poland
Speech Title: Modelling and Performance Evaluation of Packet Aggregation Mechanisms
Abstract: Packet aggregation is a valuable strategy to increase throughput, improve resource utilisation, and reduce energy consumption in access networks, high-speed Internet core networks, and cloud computing data centre networks.
The recent increase in the amounts of small packets generated by IoT networks, wireless sensor networks, and 4G/5G mobile networks has increased the need for more research on how to efficiently implement packet aggregation to meet the specific needs of these networks. The major drawback of packet aggregation mechanisms is the significant amount of delay that it introduces, making it unsuitable for packets that belong to real-time applications. The article presents a detailed review of packet aggregation applications in access networks (IoT and 4G/5G mobile networks), optical core networks, and cloud computing data centre networks.
Then we propose analytical models for evaluating the performance of packet aggregation mechanisms. They are based on diffusion approximation, where the diffusion process represents the increasing with time content of the aggregation buffer, periodically emptied following aggregation strategy. This approach allows us to consider time-dependent queueing models with time varying input flows, with general interarrival and service time distributions. The models may be fitted to any distribution of the size of aggregated and resulting packets.
Therefore they are are more general than others models presented till now.
The presented numerical examples refer to the N-GREEN (Next Generation of Routers for Energy Efficiency Networks), where smaller electronic packets called Service Data Units (SDUs) from access networks (e.g., DSL, wired and wireless LANs, 2G/3G/4G/5G mobile networks, and IoT networks), are stored following a First-in-First-out (FIFO) queueing discipline. At every time slot allocated to the buffer, the SDUs are aggregated into larger packets called Packet Data Units (PDUs) of the fixed size that are converted into optical packets and then inserted into the optical transmission system, provided that the optical transmission channel is not occupied.
Biography: Tadeusz Czachorski received M.Sc., Ph.D., D.Sc. degrees in informatics respectively in 1972, 1979, 1988, and professor title in 1999. Currently he is a professor at the Silesian University of Technology (Division of Computer Systems Theory and Design) and the director of the Institute of Theoretical and Applied Informatics of Polish Academy of Sciences, IITiS PAN, Gliwice. He spent more than five years at several French universities and research institutes (IRISA Rennes, University of Versailles, ISEM Orsay Paris-Sud, Paris-Nord, National Institute of Telecommunication) and still maintains scientific cooperation with these centres. He participated in Next Generation Internet European project concerning such issues as multiservice-multimedia, mobility, services convergence, quality of service and variable connectivity, where he was co-responsible for the work package concerning analytical, numerical and simulation methods to model performance of the Internet. He took part in Future Internet Engineering project and currently his institute coordinates a European project H2020 on safe and secure Internet of Things. He is a member of programme committees of some periodic international and national conferences, e.g. Heterogeneous Networks HET-NETS, European Workshop on Performance Engineering EPEW, Polish Teletraffic Symposium, Computer Networks, Internet in the Information Society. In 1990 - 2007 he was scientific secretary of the Committee of Informatics of Polish Academy of Sciences, 2007 - 2011 vice-president of this committee, currently member of presidium and head of the section of computer networks and distributed systems of the committee. Chair of IFIP Technical Committee TC5 "Information Technology and Applications" and member of IFIP General Assembly. His scientific interests include mathematical methods and software related to modelling and performance evaluation of wide area computer networks, especially the Internet. The methods include Markov chains, diffusion approximation and fluid flow approximation. They are used to study quality of service, traffic control mechanisms and related problems.