Clustering, grouping, and process over networks

• Authors: Zhe Dang;Min Sik Kim;Yong Wang
• Venue: Clustering, grouping, and process over networks
• Year: 2007

During the last few years there has been a rapid development in computer networks, especially wireless networks which enable mobile applications. Because of the increasing number of devices involved in network applications, it is necessary to investigate approaches to organize those devices based on their application requirements and make them perform the given tasks. The essential functionalities of a computer network is to establish relationships among network nodes, which are called grouping. An initial form of grouping, called clustering, has been observed by researchers whose research goals are to provide a network architecture that can be used to improve the network performance. In this dissertation, we first propose a number of clustering techniques including SMC, BAC, DCC, and TC, which, in some cases, outperform the existing ones.A more sophisticated form of grouping, in contrast to clustering, is to build relationships among network nodes based on the nodes’ functionalities. To do this, we first propose a specification language, called NetSpec, for studying this more general form of grouping. Using NetSpec, users can describe the desired functionalities of an individual network node, how a subset of nodes, called a group or a bond, are logically connected between each other, and, finally, how such groups evolve. For a network application specified in NetSpec, a compiler is described to translate the specification into a program that will run over a network virtual machine. In the dissertation, we describe the instruction set to support the virtual machine that runs above a physical network. The instruction set is powerful enough to execute the upper layer NetSpec specification while it is simple enough to be efficiently implemented by network protocols running on the under layer physical network. To thread instructions in the instruction set into an execution of the NetSpec specification, we also describe how to implement a non-deterministic scheduler to address fairness, synchronization, group communication control, and concurrency control.Essentially, NetSpec specifies how groups of network nodes evolve. Looking from the angle of each individual node, such an evolution can be characterize as a thread of atomic transitions, each of which is local; e.g., involving two network nodes. Inspired by this view, in the last part of this dissertation, we propose a form of network processes and study, theoretically, its computability and realization on a physical network.