Platform for Multiagent Application Development Incorporating Accurate Communications Modeling

Multiagent systems are widely recognized as a method of choice for realization of distributed time-critical applications for the smart grid. However, no general solutions have been proposed for the difficult task of system development and validation, ready for deployment, which would fully account for the underlying communication network performance. We propose a novel platform designed for this purpose, which integrates a standard multiagent development framework [Java Agent Development (JADE)] and an industry standard communications network simulator (OPNET modeler). It was realized through generic extensions of the JADE framework to provide discrete event scheduling capabilities, while the OPNET modeler was extended to provide a generic method of associating the network nodes with agents running in JADE.

The adopted method adheres to the high-level architecture standard. Importantly, applications developed using this platform may be deployed on the target system without manual modifications. A distributed protection application is presented and the performance is analyzed with respect to candidate agent behaviors and communication scenarios, demonstrating that the feasibility of the application critically depends on the choices made during its design and implementation.

C22. Avionics Full-duplex switched Ethernet (AFDX): Modeling and simulation

This paper develops a comprehensive simulation model for Avionics Full-duplex switched Ethernet (AFDX) network based on OPNET platform. Accordingly, the performance of AFDX networks is analyzed. The effect of frame size, switching delay and changing frames transmission order on the AFDX network performance are investigated.

It is found that using faster switches and small frame size reduces the fixed part of the end to end delay. Also, it affects the variable part of end to end delay due to changing of delay in switches’ buffers and frames transmission order.

Modeling and Analyzing Duty-Cycling, Pipelined-Scheduling MACs for Linear Sensor Networks

Linear sensor networks (LSNs) have recently attracted increasing attention due to the vast requirements on the monitoring and surveillance of a structure or area with a linear topology. However, there is little work on the network modeling and analysis based on a duty-cycling MAC protocol for LSNs. In this paper, we model a duty-cycling MAC with a pipelinedscheduling feature for an LSN, where each node is responsible for monitoring a certain area and can generate packets according to its sensed results. Based on the model, we analyze the network performance in terms of the system throughput, active time ratio per cycle of each node, and packet delivery latency.

Through the extensive OPNET-based simulations, we validate the model and reveal the dependency of the network performance on various system parameters. Besides enabling the effective estimation of the protocol performance by using our model, we believe that our model and analysis could provide an insightful understanding on the behavior of a duty-cycling MAC protocol and aid its design and optimization for a multi-hop LSN.

Proportional Sharing in Distributed Dynamic Spectrum Access-Based Networks

Dynamic spectrum access (DSA) is a promising technology to alleviate the exhaustion of spectral resources. To realize DSA, new technologies that enable fast discovery of the unused spectrum along with efficient spectrum management must be developed. In this paper, we propose a novel scanning algorithm and access etiquette to provide secondary devices differentiated spectrum access in a fully distributed manner.

The proposed solution does not use any common control channel or require any a prior knowledge of primary devices’ usage pattern. More importantly, hardware limitation such as imperfect sensing or lack of strict synchronization between secondary devices are taken into account in our design. A mathematical model and an Opnet-based implementation are also developed to evaluate the performance of the proposed solution in DSA networks.

User-specific QoS aware scheduling and implementation in wireless systems

In this paper, we explore user-specific QoS requirements and associated schedulers that are very critical in optimizing the spectral allocation for wireless systems. Two user-specific QoS aware schedulers are proposed that considers the user-specific QoS requirements in the allocation of resources. Depending upon whether improving the MOS (Mean Opinion Score) or both the system capacity and the MOS is the goal, a MOS improvement scheduler or MOS-plus-capacity improvement scheduler is proposed for VoIP applications.

Detailed system implementation analysis based upon LTE system specification is performed, and it is shown that very modest modifications to current protocols are needed to support user-specific QoS aware scheduling. System simulations are performed for a set of VoIP users assigned specific QoS target levels in the OPNET Modeler for LTE systems. Simulation results show that appreciable MOS or/and system capacity improvement can be achieved if such user-specific QoS requirements are considered in the proposed user-specific QoS aware schedulers. Also, it is shown that the scheduling period of up to 1000 ms doesn’t significantly impair the system performance.

A new bandwidth-efficient multicast routing scheme for mobile Ad hoc Networks

This paper proposes an improved scheme based on Bandwidth-Efficient Multicast Routing (BEMR) for Mobile Ad Hoc Networks (MANET) to further reduce the control overhead whilst increasing the overall bandwidth efficiency. After carefully studying the original BEMR design, L· new approaches are proposed to enhance the BEMR performance One is in the tree set-up phase, while the other is for broken link recovery.

Both the original BEMR and the new scheme (IBEMR) are simulated in self-developed OPNET-based platform. The IBEMR scheme eventually builds a shared tree for this multicast group rather than a dedicate tree for a particular multicast sender generated by original BEMR. The result shows that for both route setup phase and route recovery phase, the IBEMR scheme provides better multicast efficiency with further reduced communication overhead.

System analysis for optimizing various parameters to mitigate the effects of satellite vibration on inter-satellite optical wireless communication

Inter-satellite links are necessary between satellites in orbits around the earth for data transmission between satellites and also for efficient data relay from one satellite to other and then to ground stations. Inter-satellite Optical Wireless Communication deals with the use of wireless optical communication using lasers instead of conventional radio and microwave systems. Optical communication using lasers provide many advantages over conventional radio frequency systems.

A major problem existing in this wireless optical communication for inter-satellite links is the effects of satellite vibration, which results in serious pointing errors that degrade the performance. Performance of this system also depends on various parameters like transmitted power, data rate and antenna aperture which are analyzed using OptiSystem simulation software. This paper suggests ways to tackle effects of satellite vibration by optimizing the parameters of system design. The results of this study could be used further to design a feedback loop to correct effects of satellite vibrations in the system.

Design of full adder and subtractor based on MZI — SOA

A systematic model for all-optical full adder as well as full subtractor is proposed based on principle of Mach Zehnder Interferometer and using Semiconductor Optical Amplifier (MZI-SOA) configuration. MZI plays a role for ultra fast all-optical signal processing, here the non-linear property of SOA are properly utilized for designing the full adder as well as full subtractor. In this model the full adder as well as full subtractor can be effectively designed by properly selecting output terminals of MZI-SOA component.

The design is implemented with the help of OptiSystem software which is one of the powerful software for analyzing Optical components. The proposed mode shows design performance of full adder as well as full subtractor in optical domain and it seems to be future wireless technology.

Gain flattening of EDFA in C-band using RFA for WDM application

An optimal wideband gain flattened hybrid erbium-doped fiber amplifier/fiber Raman amplifier (EDFA/RFA) with the transmission of sixteen channels in C band ranging from 1528.77 nm to 1554.37 nm in wavelength division multiplexing (WDM) has been modeled to obtain maximum gain uniformity with noise figure <; 6dB. Numerous parameters which are the parameters of the erbium-doped fiber amplifier (EDFA) and the fiber Raman amplifier (RFA) define the gain spectrum of a hybrid EDFA/RFA and an effort has been made to optimize these parameters by simulating the system in optisystem software.

In this paper, we optimize the length of EDFA, and then for different values of pump powers and pump wavelengths of the RFA, the operating gain spectrum and noise figure of the hybrid EDFA/RFA is analyzed. It results in reduction in gain variation to 2.4609 dB with tolerable NF. Another technique employing gain flattening filter is analyzed which results in reduction of gain variation of EDFA to 0.0015 dB. A comparison between the two techniques is made.

Enhancing Optical-CDMA Confidentiality With Multicode-Keying Encryption

Optical codes with large cardinality and tree structures of multiple subsets of codewords for adjustable code performance and cardinality have recently been proposed. As studied in this paper, these characteristics support multicode-keying encryption for enhancing physical-layer confidentiality in optical code-division multiple-access systems and networks.

The concept of the multicode-keying encryption technique is introduced. The associated all-optical hardware is designed and validated with OptiSystem™ simulation. The theoretical analyses of confidentiality improvement by means of rapid codeword switching and multicode-keying encryption are formulated.