As ubiquitous computing begins to become a reality, the problem of estimating database performance metrics, such as database latency between mobile systems or database latencies among fixed and mobile systems, will become an ever more important issue for network engineers. The problem of estimating database performance metrics, especially latency for mobile systems, is of particular concern to ...

In the paper, we compare simulation modes and programming interfaces of three popular network simulators: ns-2, J-Sim and OPNET. Our observations and conclusions are based on a “realworld” FTP application case study, and also on our earlier projects.

This paper presents our simulation study of distributed scheduling methods for Agile All Photonic Networks using the OPNET Modeler. Both Optical Burst Switching (OBS) and Optical Time Division Multiplexing (OTDM) are studied. We first describe the OPNET implementation of OBS and OTDM in the context of an Agile All Photonic Network. The technique of discrete event simulation in the OPNET Modeler...

Owing to the model-driven development (MDD) technology, reliable network protocols could be developed with an integrated and systematic way. As performance, another core metric for evaluation of network protocols, is usually not the target of MDD process, how to connect performance evaluation to the MDD process is an important issue. This paper presents a method to enhance the reliability of pe...

in this work I have proposed different network architectures using OPNET which consists of combination of ZigBee and WiMAX topologies. ZigBee is used to sense the data from the human body whereas WiMAX is used as a backbone to deliver the data at the distant location using microwave links. The nee of using WiMAX with ZigBee arises as ZigBee network’s coverage area is limited to few meters. This...

This paper describes OPNET implementation of the Mobile Application Part (MAP) protocol within the General Packet Radio Service (GPRS) model. MAP represents an application layer protocol residing on top of the Signaling System 7 (SS7) protocol stack. In GPRS networks, MAP protocol supports signaling exchanges with Home Location Register (HLR) and Equipment Identity Register (EIR). We begin with...

Resource allocation mechanisms require that routers execute a scheduling discipline that manages buffering of packets during waiting time. Various scheduling algorithms may be implemented to govern packet transmission and control packet loss. Volume of UDP traffic is dramatically increasing due to the widely used P2P and steaming technologies. Unlike TCP, UDP protocol does not have mechanism to...