Discrete event simulation of computer networks has significant scalability issues, which makes simulating large scale networks problematic. We propose to extend the approach by combining it with analytical models for network clouds, which are much more efficient, if less accurate, than nodeby-node models. Thus, simulation scenarios containing several ISP networks become feasible. We introduce a...

The aim of this research paper is to simulation and design of wireless network by using NS-2 simulation tool. A Wi-Fi technology is used to analyzing packet flow in UDP and TCP protocol. This paper also analyze packet drop rate in UDP and TCP protocol during wireless data transmission and a brief compare of AODV and DSDV routing protocol. Keywords— LAN, MAN, NS2, AODV, TCP, UDP, WIRELESS.

This paper deals with the performance evaluation of handling streaming traffic in IP best effort networks using TFRC protocol. In our studies we check and discuss an influence of video on demand traffic and different network conditions on TFRC congestion control mechanism. Moreover, we check TFRC performance when it is sharing bottleneck with different versions of TCP. We illustrate our studies...

Estimates of the Galactic coalescence rate (R) of close binaries with two neutron stars (NS–NS) are known to be uncertain by large factors (about two orders of magnitude) mainly due to the small number of systems detected as binary radio pulsars. We present an analysis method that allows us to estimate the Galactic NS–NS coalescence rate using the current observed sample and, importantly, to as...

We present a 118-ns molecular dynamics simulation of rhodopsin embedded in a bilayer composed of a 2:2:1 mixture of 1-stearoyl-2-docosahexaenoyl-phosphatidylcholine (SDPC), 1-stearoyl-2-docosahexaenoyl-phosphatidylethanolamine (SDPE), and cholesterol, respectively. The simulation demonstrates that the protein breaks the lateral and transverse symmetry of the bilayer. Lipids near the protein pre...

A major tool used for evaluating routing protocols in ad hoc and delay-tolerant networks is simulation. Whereas the results from simulations give good insights, they are limited to the specific scenario set-up that is used. If the scenario changes, new and often time-consuming simulations have to be run. Moreover, the simulation time in packet-level simulators with fairly realistic physical lay...

The evaluation of new communication protocols for Vehicular Ad-hoc Networks (VANETs) is a hot topic in research. An efficient design and actual deployment of such software tools is crucial for any VANET. The design phase is difficult and often relies on computer simulation. The later evaluation of protocols in real VANETs is complex due to many difficulties concerning the availability of resour...

This paper addresses the problem of using unrealistic mobility scenarios for simulation of ad-hoc routing protocols. We present CAD-HOC, a cousin tool to Network Simulator (ns), which allows ad-hoc networking experimentation to be performed under visually realistic scenarios such as an airport or a bus terminal, buildings, highways and other facilities. CADHOC focuses on capturing the visual sc...

We complete the classification of parallelizable NS-NS backgrounds in type II super-gravity by adding the dilatonic case to the result of Figueroa-O'Farrill on the non-dilatonic case. We also study the supersymmetry of these parallelizable backgrounds. It is shown that all the dilatonic parallelizable backgrounds have sixteen supersymmetries. The parallelizable pp-wave backgrounds have been rec...