Simulation of the electromagnetic vector field in the high-frequency components with dispersive materials

This paper deals with parallel analysis of an electromagnetic problem for frequency-dependent materials. The solution of the linear wave equation is achieved using the finite element time domain method. A multi-pole Debye model approximates the memory of the dispersive material. The time-domain convolution is explicitly calculated using the integration by parts method. The linear recursive technique is implemented to estimate the convolution integral in each time step. The comparative study of two parallel implementations of the algorithm is presented. The discussed parallel versions are based on the domain decomposition paradigm and task decomposition scheme. The task decomposition is developed using some heuristic scheme of coupling of parallel tasks. The presented algorithms are executed over a distributed, homogeneous testbed. Some aspects connected with simulation of a broadband electromagnetic field in a dispersive and isotropic material are discussed

A Swarm Intelligence inspired Autonomic Routing Scenario in Ubiquitous Sensor Networks

Autonomic computing has attracted large amount of attention as a novel computing paradigm in the past few years. In this paper, we explore the inherent accordance between autonomic computing and swarm intelligence. Then, we propose a swarm intelligence inspired autonomic routing scenario with a targeting application area in ubiquitous sensor network. This scenario covers most of the characteristics of autonomic computing. The working flow and steps of our SI inspired autonomic routing scenario are explained in detail together with some preliminary simulation results, such as the power consumption, delivery ratio etc

A reconfigurable ethernet switch for self-optimizing communication systems

Self-optimization is a promising approach to cope with the increasing complexity of today’s automation networks. The high complexity is mainly caused by a rising amount of network nodes and increasing real-time requirements. Dynamic hardware reconfiguration is a key technology for self-optimizing systems, enabling, e.g., Real-Time Communication Systems (RCOS) that adapt to varying requirements at runtime. Concerning dynamic reconfiguration of an RCOS, an important requirement is to maintain connections and to support time-constrained communication during reconfigu-ration. We have developed a dynamically reconfigurable Ethernet switch, which is the main building block of a prototypic implementation of an RCOS network node. Three methods for reconfiguring the Ethernet switch without packet loss are presented. A prototypical implementation of one method is described and analyzed in respect to performance and resource efficiency.1st IFIP International Conference on Biologically Inspired Cooperative Computing - CommunicationRed de Universidades con Carreras en Informática (RedUNCI

SERENA: an energy-efficient strategy to schedule nodes activity in wireless ad hoc and sensor networks

In wireless ad hoc and sensor networks, an analysis of the node energy consumption distribution shows that the largest part is due to the time spent in the idle state. This result is at the origin of SERENA, an algorithm to SchEdule RoutEr Nodes Activity. SERENA allows router nodes to sleep, while ensuring end-to-end communication in the wireless network. It is a localized and decentralized algorithm assigning time slots to nodes. Any node stays awake only during its slots and the slots assigned to its neighbors, it sleeps the remaining time. SERENA is based on distributed and localized two-hop coloring. The node's color is then mapped in time slot. Thus, each node is ensured to get at least one time slot, it also gets additional time slots proportionally to its traffic rate. Such a solution adapts to varying traffic rates and supports late node arrivals. A performance evaluation allows us to compare SERENA coloring algorithm with existing ones such as DLF, both in terms of number of colors and complexity. Simulation results show that SERENA enables us to maximize network lifetime while increasing the number of user messages delivered. We quantify the slot reuse and evaluate the impact of the frame size on network performance. We then study how to dimension buffers at the router nodes. Finally, we show how SERENA improves the node energy consumption distribution and maximizes the energy efficiency of wireless ad hoc and sensor networks

FTT-Ethernet: A Flexible Real-Time Communication Protocol that Supports Dynamic QoS Management on Ethernet-based Systems

Ethernet was not originally developed to meet the requirements of real-time industrial automation systems and it was commonly considered unsuited for applications at the field level. Hence, several techniques were developed to make this protocol exhibit real-time behavior, some of them requiring specialized hardware, others providing soft-real-time guarantees only, or others achieving hard real-time guarantees with different levels of bandwidth efficiency. More recently, there has been an effort to support quality-of-service (QoS) negotiation and enforcement but there is not yet an Ethernet-based data link protocol capable of providing dynamic QoS management to further exploit the variable requirements of dynamic applications. This paper presents the FTT-Ethernet protocol, which efficiently supports hard-real-time operation in a flexible way, seamlessly over shared or switched Ethernet. The FTT-Ethernet protocol employs an efficient master/multislave transmission control technique and combines online scheduling with online admission control, to guarantee continued real-time operation under dynamic communication requirements, together with data structures and mechanisms that are tailored to support dynamic QoS management. The paper includes a sample application, aiming at the management of video streams, which highlights the protocol’s ability to support dynamic QoS management with real-time guarantees

Parallel Implementation of Relational Algebra Operations on a Multi-Comparand Associative Machine

In this paper, we propose a new multi-comparand associative machine (MCA-machine) and its application to relational algebra operations. We first offer a new efficient associative algorithm for the multi-comparand parallel search. It generalizes the Falkoff associative algorithm that performs a parallel search in a matrix based on the exact match with a given pattern. Then we apply the new associative algorithm to implement one group of the relational algebra operations on the MCA-machine. Then, we propose efficient associative algorithms for implementing another group of the relational algebra operations. The proposed algorithms are represented as corresponding procedures for the MCA-machine. We prove their correctness and evaluate their time complexity

Simplifying data path processing in next-generation routers

ABSTRACT Customizable packet processing is an important aspect of next-generation networks. Packet processing architectures using multi-core systems on a chip can be difficult to program. In our work, we propose a new packet processor design that simplifies packet processing by managing packet contexts in hardware. We show how such a design scales to large systems. Our results also show that the management of such a system is feasible with the proposed mapping algorithm

Multi-Comparand Associative Machine and its Application to Relational Algebra Operations

In this paper, we propose a new multi-comparand associative machine (MCA-machine) and its application to relational algebra operations. We first offer a new efficient associative algorithm for the multi-comparand parallel search. It generalizes the Falkoff associative algorithm that performs a parallel search in a matrix based on the exact match with a given pattern. Then we apply the new associative algorithm to implement a group of the relational algebra operations on the MCA-machine. The proposed algorithms are represented as corresponding procedures for the MCA-machine. We prove their correctness and evaluate their time complexity