Cellular Network Systems Research Articles

Global exponential stability and periodicity of cellular neural networks with variable delays

The Letter presents sufficient conditions ensuring the global exponential stability and existence of the periodic solution for cellular neural networks with variable delays. The results allow for the consideration of all unbounded neuron activation functions (but not necessarily surjective), in particular, can analyze the exponential stability and periodicity for the linear cellular neural networks. The work provides one such method which can be applied to cellular neural networks systems with variable delays. The method, based on the theory of fixed point and differential inequality technique. The applicability of the present results is demonstrated by two examples.

FAIR SCHEDULING WITH DYNAMIC RESOURCE ALLOCATION IN CDMA/GPS SYSTEM FOR IP-MULTIMEDIA WIRELESS NETWORKS

Over the last few years, research has provided the cellular network system with the capability of fair channel access to multimedia users, while at the same time, insuring a given QoS and optimal utilization of network resources. Scheduling policies play a crucial role in achieving desired QoS goals and optimum utilization of limited resources. Many scheduling approaches have been proposed for the efficient utilization of the network resources. This paper deals with the experimental study of a new proposed scheduling policy for achieving fairness, QoS, and optimal use of resources. The proposed scheduling policy Code Division Multiple Access based on Generalized Processor Sharing with Dynamic Weights (CDMA/GPS-DW) is an improvement of a previous GPS policy. Simulation results show that the proposed policy achieves fairness of the specified QoS and makes efficient use of the network resources.

Boundedness and stability for nonautonomous cellular neural networks with delay

The Letter studies the nonautonomous delayed cellular neuraln networks systems. By applying Liapunov functional method, the ultimate boundedness, global exponential stability and the existence of periodic solutions are established. The results obtained in this Letter are new and useful.

Dual-frequency dual-polarized slot-coupled compact microstrip antenna for communication systems

A new design of a dual-frequency dual-polarized square microstrip antenna fed along the diagonal, embedded with a square slot having three extended stubs for frequency tuning, is introduced. The proposed antenna was fabricated using a standard photolithographic method and the antenna was tested using the HP 8510C Vector Network Analyser. The antenna is capable of generating dual resonant frequencies with mutually perpendicular polarizations and broad radiation pattern characteristics. Such dual-frequency designs find wide applications in personal mobile handsets combining GSM and CDS 1800 modes, and applications in which different frequencies are used for emission and reception such as personal satellite communications and cellular network systems.

From equations to patterns: Logic-based approach to general systems theory

Many complex self-organizing systems may not be easily modeled with the help of differential equations. Modern studies in complexity generated new kinds of modeling paradigms such as Cellular Automata (CA), Boolean Networks, and Multiagent Systems. Such models are built from large numbers of interacting units with simple behavior defined in terms of production rules. These models are capable of reproducing unexpected complex organization patterns where the character of the organization could not be derived from the character of the rules defining the behavior of units. Organization that is not evident from the dynamic rules is called emergent . The existence of emergent organization demonstrates the inadequacy of the traditionally accepted association of systems organization with the dynamic equation of the system. The main objective of the paper is to describe new General Systems Theory (GST) framework that gives appropriate account of new dimensions of organization and accommodates new approaches to modeling of complex adaptive systems (CAS). To describe system states and state sequences we use concept model from formal semantics. Dynamics of a system are described with the help of patterns or production rules. The isomorphism of systems is naturally represented as model isomorphism. The organization of a system is a set of formulae with free variables, which have interpretation on the models that represent the system. The framework introduced here is developed as a part of our eco-modeling project. We also discuss the architecture of ecological simulator, LEM (Logic for Eco-Modeling), and its implementation in Visual Prolog that serves as an example of practical application of the framework.

Cellular telephone networks and random maps in hypergraphs

Let H=(V,E) be an r-uniform hypergraph of size n such that each edge of H meets at most d others. A finite map f : X→E induces a bipartite graph G H,f =(V f,E f) with vertex set V f = X∪ Y, where Y=⋃ E, and with edge set E f={{x,y} : x∈X, y∈f(x)} . We study matchings in the bipartite graph induced by a random f. The study was suggested by consideration of the call sequence acceptance behavior of a load-sharing system for cellular telephone networks, invented by Matula and Yang.

Long-time behavior of transient solutions for cellular neural network systems

By establishing concept on transient solutions of general nonlinear systems converging to its equilibrium set, long-time behavior of solutions for cellular neural network systems is studied. A stability condition in generalized sense is obtained. This result reported has an important guide to concrete neural network designs.

Implementation of a diagnostic and troubleshooting multi-agent system for cellular networks

This article presents the implementation of a maintenance application for cellular switching system using the multi-agent paradigm. The main philosophy behind the design of the multi-agent system is based on the TMN framework, where each agent can mapped with one or several TMN functional blocks. Copyright © 1999 John Wiley & Sons, Ltd.

A Dedicated Multi-Chip Programmable System for Cellular Neural Networks

Cellular Neural Networks (CNN’s) represent a remarkable improvement in the hardware implementation of Artificial Neural Networks (ANN’s). In fact, their regular structure and their local connectivity feature contribute to render this class of neural networks especially appealing for VLSI implementations. CNNs are widely applied in several fields, including image processing and pattern recognition. In this research, the authors already presented two fully digitally programmable CNN chips with 3×3 (3×3DPCNN chip) and 6×6 cells (6×6DPCNN chip) respectively. In this paper, a system with twenty of the latter chips will be presented. The main features of this electronic system consist of the full digital programmability of the templates, the digital input/output for logic operations, the analog outputs for dynamic analysis and the implementation of space-variant as well as space-invariant CNNs.

A call admission control strategy for multiservice wireless cellular packet networks

A simple connection control system for multiservice cellular wireless networks is presented. Mobile stations are classified depending on the traffic they generate (e.g., voice, data). Within each class, two subclasses are also identified: stations which have originated inside the cell and stations which come from adjacent cells. The connection control mechanism is carried out by considering a number of priorities among the various classes and their subclasses. It works on two levels: static and dynamic. The static level looks at “packet-level” quality of service (QoS), such as cell loss and delay, while the dynamic level takes care of connection dynamics and allows the load of the system to be driven with respect to the various subclasses. Results that illustrate the performance of this control mechanism are presented.