Guest Editorial: Recent Advances in Modeling and Simulation of Network Systems

Computer communication networks have become more complex and widely used by all organizations and applications. Intensive research efforts are being conducted worldwide to tackle various challenging issues. Among the important research efforts in this regard is performance evaluation of such complex systems. Modeling and simulation techniques are playing a vital role in the development and progress of this technology as a means to gauge the capacities and limits of new schemes, designs, protocols, and algorithms before they are developed and built [1-5]. This special issue is aimed at presenting recent original research results in this vital field. The articles included in this special issue are based on selected extended versions of best papers accepted at the 2005 International Symposium on Performance Evaluation of Computer and Telecommunication Systems, SPECTS 2005. We only accepted four papers in this special issue out of many selected extended versions of papers accepted in SPECTS 2005. This means that these accepted papers have undergone a thorough and a critical review process by experts in the field. Our goal in putting together this special issue is to define a set of high-quality articles that deal with various aspects of modeling and simulation of computer communication networks. The articles cover the Multicast Service Overlay Network (MSON) design problem, a new scheme for a network service that guarantees a minimum throughput to flows accepted by the admission control (AC) mechanism, which is suitable for TCP flows, disruption-tolerant geographic routing for wireless ad hoc networks, and design of heterogeneous wireless networks using a Universal Mobile Telecommunication System (UMTS) core and integrating a variety of wireless local-area networks (WLANs).