Ns3 Projects for B.E/B.Tech M.E/M.Tech PhD Scholars.  Phone-Number:9688312542   E-mail:ns3simulation@gmail.com

Performance evaluation of ADV DSR & GOD in VANET for city & highway scenario

VANET has grasp the attention of various researchers in this field due to its wide range of applications in different fields i.e comfort, safety and entertainment. It is very expensive to test every networkprotocol or any network algorithm in real network by connecting a number of routers, computers and data links.

Thus, in this paper QOS parameters like throughput, packet drop and collision rate for different routing protocols performed on simulator to prevent from damage or unpredictable result and without spending money.

Analysis of the Scalability and Stability of an ACO Based Routing Protocol for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are often deployed in remote and hostile areas and because of their limited power and vulnerability, the sensors may stop functioning after sometime leading to the appearance of holes in a network. A hole created by the non-functioning sensors in turn severs the connection between one side and the other side of the network and alternative routes need to be found for the network traffic. Prior research tackled the holes problem only when packets reach some nodes near the hole. In this case, the feedback packets are generated and accordingly the data packets need to be rerouted to avoid the holes.

The traffic overhead for rerouting consumes additional battery power and thus increases the communication cost as well as reducing the lifetime of the sensors. To deal with the dynamical changes in network topologies in an autonomous manner, ant colony optimization (ACO) algorithms have shown very good performance in routing the network traffic. In this paper, we analyze the scalability and stability of the ACO-based routing protocol BIOSARP against the issues caused by holes in WSNs. Network simulator 2 (ns-2) is utilized to perform the analysis. Findings clearly demonstrate that BIOSARP can efficiently maintain the data packet routing over a WSN prior to any possible holes problems, by switching data forwarding to the most optimal neighboring node.

A cross validation of network system models for delay tolerant networks

This paper presents a cross validation of network system models in two simulation tools, namely the ONE Simulator and Scenargie, for the simulation of Delay or Disruption Tolerant Networks (DTNs). The study compares the simulation results from three network system models provided by the twosimulators as well as their efficiency for a commonly used DTN scenario. The results show a fundamental problem inherent to the time stepped approach that may introduce an unacceptable level of inaccuracies in the predicted DTN performance.

Also, limiting such inaccuracies gives the time stepped approach no runtime performance superiority over the event driven approach. Further, the study shows that the DTN performance is highly sensitive to the link establishment overheads, which may change the predicted end-to-end message delivery latencies by an order of magnitude. Moreover, other details of the network system are important when the target network is expected to be highly loaded with communication traffic.

A calibration based thermal modeling technique for complex multicore systems

A calibration based method to construct fast and accurate thermal models of the state-of-the-art multicore systems is presented. Such models are usually required during Design Space Exploration (DSE) exercises to evaluate various task-to-core mapping, associated scheduling and processor speed-scaling options for their overall impact on the system temperature. Current approaches require modeling the thermal characteristics of the target processor using numerical simulators, which assume accurate information about several critical parameters (e.g., the processor floorplan). Such parameters are not readily available, forcing the system designers to use time and cost intensive, and possibly error-prone techniques such as using heat maps for reverse-engineering such parameters.

Additionally, advanced power and temperature management algorithms commonly found in the state-of-the-art processors must also be accurately modeled. This paper proposes a calibration based method for constructing the complete system thermal model of a target processor without requiring any hard-to-get information such as the detailed processor floorplan or system power traces. Taking an example of a sufficiently complex Intel Xeon 8-core processor, we show that our approach yields an accurate thermal model, which is also lightweight both in terms of memory and compute requirements to be practically feasible for DSE over current processors.

A new RA-DA hybrid MAC approach for DVB-RCS2

This paper proposes a new MAC scheme for DVB-RCS2 aimed to efficiently address M2M/SCADA traffic. The proposed scheme relies on the idea to complement Random Access (RA) schemes with Dedicated Access (DA) schemes, when traffic spikes feed the network. The rationale is to control the offered load on the RA slots pool to keep the packet loss, due to collisions, under a pre-defined threshold.

New MAC algorithms are based on the interaction between NCC and STs and add a number of new features and dynamics, such as selective switching on a full DA configuration for greedy STs. A prototype implementation has been developed on the Network Simulator NS-2 to verify the effectiveness of the proposed approach in a preliminary study case. Achieved results are promising and allow highlighting the main MAC scheme dynamics, leading to practical considerations and open issues to be addressed in future activities.

Real-Time Low Voltage Network Monitoring—ICT Architecture and Field Test Experience

Traditionally, distribution network monitoring has been focused on primary substations (i.e., high voltage/medium voltage level), whereas low voltage (LV) network has not been monitored at all. With rapid growth and penetration of distributed energy resources in LV grids, there is growing interest in extending the real-time monitoring to LV level. The framework program FP7 European Project INTEGRIS proposes an integrated real-time LV network monitoring solution and implements it in a cost-efficient way.

This solution integrates smart metering data with secondary substation measurements to get a more accurate and real-time view about LV grid, uses “decentralized” distribution management architecture to optimize data flow, and uses International Electrotechnical Commission 61850 Standard-based interfaces to improve interoperability. This paper focuses on information and communications technology perspective, explains the implementation details of this monitoring solution, and presents its functionality/performance testing results from two distribution system operator field trials and from real-time digital simulator laboratory.

A LiFePO4 battery discharge simulator for EV applications — Part 2: Developing the battery simulator

This paper, the second of the series on developing a LiFePO4 (LFP) battery discharge simulator for EV applications, presents an approach for developing the battery simulator. After the optimal battery model was established, in the first paper, the main drawbacks of battery simulator are addressed and a new strategy is proposed.

This strategy uses neural networks (NN) for online estimation of the battery parameters during discharge. The proposed simulator is validated by comparisons with a typicalsimulator and data from a LFP battery submitted to discharge profile in concordance with a driving cycle.

Ctherm: An Integrated Framework for Thermal-Functional Co-simulation of Systems-on-Chip

This paper presents therm, an integrated framework for cycle-accurate thermal and functional evaluation of systems-on-chip. The presented framework enables accurate characterization of thermal behaviour by generating detailed physical models for components based on input specifications, and simulating them within a tightly integrated co-simulation platform with an embedded thermal simulator.

Therm’s fine-grained modelling approach yields 70% higher accuracy in hotspot resolution as compared to conventional approaches that abstract component internals. Simulation runtime time is reduced by up to 36% over conventional continuous approaches through the use of thermal check pointing, enabling the fast-forwarding of thermal simulations without loss of thermal continuity.

Cost Estimation of Parallel Constrained Producer-Consumer Algorithms

Cost estimation is crucial in the performance modeling of parallel algorithms and allocation of computational resources on distributed systems. This paper presents a novel methodology for estimating the cost of constrained producer-consumer (CPC) algorithms. In CPC algorithms, the computation is performed by classes of nodes (tasks), separated in time. The methodology combines data flow analysis with communication latencies to determine the production and consumption of data on different processors, which helps in determining the amount of computations and communication. The cost metric that we develop in this paper uses computational imbalances and communication load, and determines a single cost value.

The resulting metric is unique, as it provides the first model that targets CPC algorithms. It has wide application in Genetic Algorithms, molecular dynamics, scheduling schemes and computational epidemiology. We provide a general method for determining the application-specific constants of the cost metric. As an example, we extract the constants for EpiSimdemics (a highly scalable contagion simulator), and give guidelines for applying the procedure to other CPC algorithms. Our evaluations show that the cost metric estimated the execution times of a contagion simulator with less than a 6.5% error. The metric can be used in optimal assignment of computational resources.

A raptor enabled data carousel for enhanced file delivery and QoS in 802.11 multicast networks

802.11 WLANs do not provide any standardized solution for reliable data multicast. Multicast packets are delivered to multiple clients as a simple broadcast service without support for Automatic Repeat Request. Hence, a fixed low speed (robust) transmission mode is generally used to improve the reliability of multicast files. However, this results in the inefficient use of bandwidth. This paper details a reliable and efficient Wi-Fi multicast delivery solution for use in challenging outdoor environments.

We propose an Application Layer Forward Error Correction enabled data carousel for reliable multicast transmission over standard 802.11 WLANs. To quantify the benefits of the proposed system, results are reported from a cross-layer simulator combining novel outdoor ray-tracing, a Physical layer abstraction simulator (to rapidly quantify the radio performance), a RaptorQ enabled multicast data carousel simulator and an optimal access point deployment tool. The simulation results demonstrate that RaptorQ enabled carousels (compared to standard carousels) significantly reduce the average response time and increase the percentage of satisfied users in a multicast network.