Most EAI tools facilitate the integration of several application services to implement a designed workflow process. The individual application systems are coordinated by a workflow-driven broker-server that integrates the system through web-service technologies such as SOAP and XML. This paper describes a performance-evaluation methodology that we have developed for the analysis of such integra...

Multi-hop ad-hoc networks suffer from the presence of hidden and exposed nodes that diminish aggregate network throughput. While there are various approaches to mitigating these problems, in this work we focus exclusively on the role of physical carrier sensing (PCS). Specifically, tuning the PCS threshold leads to a trade-off between the ‘exposed’ and ‘hidden’ areas. The contributions of this ...

Satellite communications system uses various satellites to transmit radio signals between earth terminals. A typical operational link includes an active satellite and two or more earth terminals. Satellite communication is one of the significant factor from the space programs and has made a major contribution to the international communication. There are various types of information that can be...

The need for coupling Heterogeneous Wireless Networks (HWNs) such as WLAN, WiMAX or UMTS, play a great role in developing towards fourth generation of wireless networks. Hence, the algorithms for these networks must be developed especially handoff algorithms to present a better performance in such heterogeneous networks. In this paper, several projects have different types of networks were impl...

As Wireless Mesh Networks (WMNs) are continuously gathering momentum, security has become a pivotal issue. Denial of Service (DoS) attack is a serious threat looming over WMNs due to their plug-and-play architecture. Unfortunately, a DoS attack is very difficult to stop due to the rampant spoofing of source IP addresses by the attackers. The best anti-dote, is to fix the problem at its root by ...

Networked wireless sensors in a harsh terrain typically are battery operated and, therefore, require energy efficient network protocols. In order to ease the analysis of the energy usage of proposed network protocols, this paper proposes an energy module, implemented in OPNET, to determine the energy consumption over time during network simulation. Multiple energy consumption modes, such as tra...

Modeling and simulation can help to validate and evaluate the performance of wireless sensor networks (WSNs) within specific applications. In order to resolve the issue of the restriction on node mobility in existing Zigbee WSN simulation models, this paper proposes a Zigbee compliant new simulation model using the OPNET simulator. Based on the Zigbee MAC layer model in OPNET Modeler, we develo...