19-10-2012, 11:44 AM
OPNET
OPNET.pptx (Size: 515.6 KB / Downloads: 26)
Abstract
Wireless local area networks (WLANs) are in a period of great expansion and there is a strong need for them to support multimedia applications
We introduced the OPNET network simulation as a primary tool for network simulation.
OPNET(version 10.0) network simulation tool will enhance the practical skills of future network engineers. academic network by using WLAN,which has been used in this research as an example.the performance matrices used in this example are thoroughput,end-to-end delay,retransmission attempts and load
objectives
The main objectives of our simulation experiments are:
To reinforce the networking theory with hands-on experiments and deeper understanding of networking principles and concepts.
To be able to build, observe, experiment, and measure variety of networks.
To balance the breadth and depth of knowledge in an introductory networking course
To provide additional learning opportunities to discover knowledge.
To meet these objectives, the following properties are essential for the network simulator to be used for the laboratory experiments:
• Ability to simulate a wide range of networking technologies
• Ease of use
Why opnet
OPNET is the best network simulator to meet our goals for the following reasons:
• OPNET is much easier to use than NS-2. It provides a very convenient Graphic User Interface (GUI) and is very easy to learn.
• OPNET can be used to model the entire network, including its routers, switches, protocols, servers, and the individual applications they support. A large range of communication systems from a single LAN to global inter-networks can be supported.
• OPNET software (with model source code) is available for FREE to the academic research and teaching community. Students can download and install OPNET easily.
• The OPNET's discrete event engine for network simulations is the fastest and most scalable commercially available solution. It usually takes just a few minutes to complete simulations of most lab experiments.
Key System Features
Object orientation
Specialized in communication networks and information systems
Hierarchical models
Graphical specification
Flexibility to develop detailed custom models
Automatic generation of simulations
Application-specific statistics
Integrated post-simulation analysis tools
Typical Applications of OPNET
Standards-based LAN and WAN performance modeling
Internetwork planning
Research and development in communications architectures and protocols
Distributed sensor and control networks, on-board systems
Resource sizing
Mobile packet radio networks
Satellite networks
CONCLUSION
The results obtained from simulation shows that Enhanced Distribution Coordination Function provides efficient mechanism for service differentiation and hence provides quality of service to the Wireless LAN. However, this improvement comes at a cost of a decrease in quality of the lower priority traffic up to the point of starvation. The acquisition of the radio channel by the higher priority traffic is much more aggressive than for the lower priority. Higher priority traffic benefited, while lower priority traffic suffered.
The wireless devices using EDCF as MAC protocol would be available in market in the next coming two years. Presently, all of the wireless devices use DCF as the default MAC protocol and PCF as the optional functionality