OPNET Simulation Research Articles

Performance analysis of integrated WLAN-WiMAX-UMTS networks for multimedia applications

Next Generation Wireless networks (NGWN) are the integration of different types of available wireless networks. These integrated networks will provide seamless connectivity for multimedia user applications. Among various wireless networks, the networks such as Wireless Local Area network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX) and Universal Mobile Telecommunications System (UMTS) have their own unique characteristics and support for wide range of multimedia user applications. So, the integration of these networks and their performance analysis in respect of Quality of Service (QoS) is a major concern nowadays. Hence, this paper deals with the integration of WLAN, WiMAX and UMTS networks by considering QoS parameter. Further, the integration of these networks are analyzed with loose coupling and tight coupling architecture along with and without QoS. Furthermore, the performance analysis of the above mentioned integrated network for multimedia applications is also done. The simulation is performed through Opnet simulator.

MNDM: MEMS-based N-dimensional modular hybrid data center network

The rapid development of virtualization technology and cloud computing technology for the data center has brought the explosive growth of business volume and scale. The data center network is facing new challenges, such as ultra-high bandwidth requirements and energy-efficiency. The introduction of optical interconnect technology improves the performance of data center networks by virtue of less cost of devices, complexity, power consumption. However, there are still three major problems when adopting optical switching, which are constraint of centralized control system, non-modularity and poor scalability. Aiming at these problems, this letter proposes a MEMS-based N-dimensional modular hybrid data center network (MNDM) and corresponding MEMS scheduling strategy. We evaluate the performance of MNDM via OPNET simulation and results demonstrate that the MNDM architecture is stable in saturation point of latency and saturation point of throughput when the network size changes or network traffic changes.

Hybrid energy-efficient APTEEN protocol based on ant colony algorithm in wireless sensor network

Due to the limited energy of the sensor nodes, the unreasonable clustering routing algorithm will cause node premature death and low utilization of energy efficiency in wireless sensor network (WSN). In Adaptive Threshold-sensitive Energy Efficient Network (APTEEN), the assignments of the cluster head (CH) are much heavier than other nodes. The CH unbalanced energy dissipation between nodes that make them die prematurely. Ant colony algorithm can avoid this problem, so this paper presents a double cluster heads Adaptive Threshold-sensitive Energy Efficient Network based on ant colony (ADCAPTEEN). ADCAPTEEN optimizes the cluster head election method compared with APTEEN. It suggests that one master cluster head (MCH) and one vice cluster head (VCH) will be selected in each cluster. The double cluster heads (DCH) can co-work on data collection, fusion, transition, etc. To make routes more stable and energy efficient, this paper proposes a Multiple Adaptive Threshold-sensitive Energy Efficient Network based on Ant-colony (AMAPTEEN). It is the optimization of ADCAPTEEN. And CH selects intermediate node (IM_node) multiple times with ant colony algorithm per round in each cluster, and this way forms multiple route transmission data. Simulation in OPNET proves that compared with APTEEN, ADCAPTEEN reduces energy dissipation, improves node survival rate, and extends network life cycle. AMAPTEEN delays the time of node death, balances energy consumption, and extends network lifetime further operating in the same settings compared with ADCAPTEEN. The proposed two algorithms have good scalability, and they are suitable for large-scale network.

RETRACTED ARTICLE: QOS distributed routing protocol for mobile ad-hoc wireless networks using intelligent packet carrying systems

The wireless network should provide high throughput and positive status and this paper suggest a system that supports real-time communications with excellence of service necessities for application based on wireless communications. In addition a hybrid network that interconnects both mobile networks and wireless networks. By inheriting the features of Solid Rocket Booster technology for mobile and wireless networks the race condition, and invalid condition problem has been solved. The number of packets received may vary based on the parameter like mobility, energy, memory, bandwidth, jamming and other parameter. In past years many algorithm has been proposed for increasing the probability of packet delivery but it’s still a challenge. This paper uses an algorithm called intelligent packet carrying systems; it provides a tracking mechanism that tracks nodes in rural places. The effectives and reability has been calculated and the results are obtained using OPNET simulator.

A joint optimization method for NoC topology generation

The increasing demand on efficient intra-chip communication of multicore systems has driven the interconnection structure to evolve from bus/ring to Network-on-Chip (NoC). NoC design is fundamentally based on network topology generation and floorplanning. This paper proposes a joint optimization method to generate network topologies based on the floorplanning of heterogeneous IP cores for a given application-specific NoC. This method starts with clustering the heterogeneous IP cores according to their communication workloads using fuzzy clustering. It proceeds to apply a genetic algorithm to optimize the floorplanning by minimizing power consumption and/or chip area. By adding a router to each cluster of IP cores, network topologies are further generated via connecting routers based on the principles of scale-free networks. Experiments with a video processing application show that the optimized floorplanning of IP cores can be achieved by either minimizing the power consumption or chip area. An OPNET simulator is used to evaluate the performance of the NoC designed based on the proposed method. Experimental results demonstrate that the performance requirements of the application-specific NoC can be satisfied.

Improved Routing Protocol in Mobile Ad Hoc Networks Using Fuzzy Logic

In mobile ad hoc networks, route selection is one of the most important issues that is studied in these networks as a field of research. Many articles trying to provide solutions to choose the best path in which the important parameters such as power consumption, bandwidth and mobility are used. In this article, in order to improve the solutions presented in recent papers parameters such as power remaining, mobility, degree node and available bandwidth are used by taking the factors for each parameter in proportion to its influence in choosing the best path. Finally, we compare the proposed solution with the three protocols IAOMDV-F, AODVFART and FLM-AODV with the help of OPNET simulation program based on network throughput, routing discovery time, the average number of hops per route, network delay.

Performance Evaluation of Wireless 802.11n Using Level 2 and Level 3 Mobility

Objectives: To present a performance evaluation of a WI-FI network under the impact of mobility. It alsomakes the study and the evaluation cover for level 2 and level 3 mobility. Methods/Statistical Analysis: The OPNET simulator was used for simulating the scenarios of proposed architectures. For performance evaluations, the different parameter has considered, such as mobility speed, number of connected users and channel access methods. Findings: The main interest of this paper is to reveal the mobility schema that ensures a better continuity of providing services to mobile users moving between different Wi-Fi access points while considering a number of constraints related to the quality of service. Application/Improvements: Deploying level 2 roaming gives better results compared with level three roaming using MIPv4, while increasing the speed of mobility and the number of clients. Keywords: Level 2 Mobility, Level 3 Mobility, Performance Evaluation, MIPv4, 802.11 n

Energy-efficient selection of cluster headers in wireless sensor networks

Clustering is vital for lengthening the lives of resource-constrained wireless sensor nodes. In this work, we propose a cluster-based energy-efficient router placement scheme for wireless sensor networks, where the K-means algorithm is used to select the initial cluster headers and then a cluster header with sufficient battery energy is selected within each cluster. The performance of the proposed scheme was evaluated in terms of the energy consumption, end-to-end delay, and packet loss. Our simulation results using the OPNET simulator revealed that the energy consumption of our proposed scheme was better than that of the low-energy adaptive clustering hierarchy, which is known to be an energy-efficient clustering mechanism. Furthermore, our scheme outperformed low-energy adaptive clustering hierarchy in terms of the end-to-end delay, throughput, and packet loss rate.

A Comparison of Near-Hidden and Information Asymmetry Interference Problems in Wireless Mesh Networks

Multi-radio Multi-channel (MRMC) Wireless Mesh Networks (WMNs) have made quick progress in current years to become the best option for end users due to its reliability and low cost. Although WMNs have already been used still the capacity of WMNs is limited due to information asymmetry and near hidden interference among frequency channels. In the past, various research studies have been done to investigate both these issues. To minimise both these interference types and maximise network capacity; channel assignment has always been a critical area of research in WMNs. In this research, a comparative analysis is done between NH and IA interference based on their impact on network capacity. This comparison is made using the existing Optimal Channel Assignment Model (OCAM). After extensive simulations, it is figured out that NH interference performs a major role in degrading overall network capacity up to 4% in comparison to IA interference. Further, in this research an optimal channel assignment model Information Asymmetry and Near Hidden Minimization (INM) model is proposed that collectively minimises both NH and IA interference problems. The proposed model considers three non-overlapping channels 1, 6 and 11 from IEEE802.11b standard. For simulations, four different Multi-radio Multi-channel Wireless mesh topologies have been considered to find out the average network capacity. An extensive simulation in OPNET shows that the proposed INM model performs 7% better than the existing OCAM model in maximising the WMN net capacity.

Opnet Based Performance Analysis and Comparison Among Different Physical Network Topologies

Physical network topology is the configuration of computers, cables and other peripherals as a geometrical shape. There are many types of topologies each of them has many advantages and disadvantages. For high performance Local Area Networks (LANs), the builder of a network should select the best physical network topology. This paper analyzes three basic network topologies including bus, star and ring for different number of connected nodes (various network topology size) using OPNET simulator. Four scenarios are configured for each topology with number of connected nodes equal to 5, 10, 15 and 20 for senario1, 2, 3 and 4 respectively. In this analysis, four parameters investigated in Delay (Sec.) for the complete network, Load (Bits/Sec.), Traffic Received (Bits/Sec.) and the number of Collision for single node (server). Performance comparison is made in each topology separately based on various network size and another comparison is also made between these topologies for the same number of connected devices. The comparison results indicate that performance decreased when the network size increased and also show that bus topology is more effected than two other topologies.

Distributed and Jamming-Resistant Channel Assignment and Routing for Multi-Hop Wireless Networks

We are becoming more reliant on multi-hop wireless networks (MWNs) for public safety, tactical/military, and last mile Internet communications. The architecture of an MWN can be flat , as in ad-hoc networks or hierarchical , as in mesh or sensor networks. Today, the lower cost and smaller size of radios enables multiple radios to exist in a device. Hence, simultaneous transmissions on orthogonal channels are possible, which multiplies the performance of MWNs. However, an efficient communication is only possible if every device has reliable connection. A connected MWN can be created using a meticulous channel assignment (CA) scheme that reduces congestion and interference. In addition, CA needs to handle jamming attacks. The medium access control (MAC) layer is responsible for CA related tasks. However, CA results in topology changes that affect routing decisions taken at the routing layer, which could lead to unreliable network. This strong interrelationship requires a cross-layered approach to ensure reliable connectivity. In this paper, we formulate this cross-layer problem as network-path cost optimization. Because the problem is NP-hard, we propose a dynamic and distributed heuristic CA and routing scheme that is applicable for both flat and hierarchical MWNs and that is also resistant to jamming attacks. We call it distributed jamming resilient channel assignment and routing (DJ-CAR) scheme. The performance of DJ-CAR, with that of existing schemes, is compared using an OPNET simulator.

Cross Layer Optimization and Simulation of Smart Grid Home Area Network

An electrical “Grid” is a network that carries electricity from power plants to customer premises. Smart Grid is an assimilation of electrical and communication infrastructure. Smart Grid is characterized by bidirectional flow of electricity and information. Smart Grid is a complex network with hierarchical architecture. Realization of complete Smart Grid architecture necessitates diverse set of communication standards and protocols. Communication network protocols are engineered and established on the basis of layered approach. Each layer is designed to produce an explicit functionality in association with other layers. Layered approach can be modified with cross layer approach for performance enhancement. Complex and heterogeneous architecture of Smart Grid demands a deviation from primitive approach and reworking of an innovative approach. This paper describes a joint or cross layer optimization of Smart Grid home/building area network based on IEEE 802.11 standard using RIVERBED OPNET network design and simulation tool. The network performance can be improved by selecting various parameters pertaining to different layers. Simulation results are obtained for various parameters such as WLAN throughput, delay, media access delay, and retransmission attempts. The graphical results show that various parameters have divergent effects on network performance. For example, frame aggregation decreases overall delay but the network throughput is also reduced. To prevail over this effect, frame aggregation is used in combination with RTS and fragmentation mechanisms. The results show that this combination notably improves network performance. Higher value of buffer size considerably increases throughput but the delay is also greater and thus the choice of optimum value of buffer size is inevitable for network performance optimization. Parameter optimization significantly enhances the performance of a designed network. This paper is expected to serve as a comprehensive analysis and performance enhancement of communication standard suitable for Smart Grid HAN applications.

Simulations of Grant Allocation in NG-PON2 Networks Using OPNET Modeler

Passive optical networks are the most promising networks for the future. In 1998, the first standard of PONs was developed. Since that time, quality of optical transmissions and technologies has been massively improved and today's standards are capable of transferring an enormous amount of data. For example, NG-PON2 networks are able to transfer up to 40 Gbit/s, which means these networks provide subscribers with a symmetric bandwidth up to 10 Gbit/s using 4 different wavelengths. The higher transmission speeds are required, the more sophisticated bandwidth allocation reflecting requirements of each ONU in real-time is necessary. This article deals with implementation of NG-PON2 networks using OPNET Modeler and simulations of static and dynamic grants allocations. We also present a modification of dynamic bandwidth allocation for increasing the free bandwidth of idle ONU to heavily loaded ONU(s). We propose a simplified NG-PON2 network, for example, activation machine for ONUs is not implemented.

BAVP: Blockchain-Based Access Verification Protocol in LEO Constellation Using IBE Keys

LEO constellation has received intensive research attention in the field of satellite communication. The existing centralized authentication protocols traditionally used for MEO/GEO satellite networks cannot accommodate LEO satellites with frequent user connection switching. This paper proposes a fast and efficient access verification protocol named BAVP by combining identity-based encryption and blockchain technology. Two different key management schemes with IBE and blockchain, respectively, are investigated, which further enhance the authentication reliability and efficiency in LEO constellation. Experiments on OPNET simulation platform evaluate and demonstrate the effectiveness, reliability, and fast-switching efficiency of the proposed protocol. For LEO networks, BAVP surpasses the well-known existing solutions with significant advantages in both performance and scalability which are supported by theoretical analysis and simulation results.

Study on Communication Service Strategy for Congestion Issue in Smart Substation Communication Network

Shared networks can improve the efficiency of smart substation communication infrastructure, but they pose challenges for the real-time performance and reliability of communication. By analyzing the traffic rate and causes of congestion in a substation environment, we propose a communication service strategy using a message information label to manage the congestion issues. This strategy implements fast identification and filtering of messages by condensing key information into a message label at intelligent electronic devices and checking it along with traffic rates at switches. We put forward a communication scheduling method called distributive length WRR_LLQ that adapts to the different characteristics and real-time demand of various message types. OPNET simulation results show that the strategy successfully identifies and discards disguised error messages with high traffic rates, avoids timeouts and packet drops in the transmission process of important messages when congestion occurs, and reduces the transmission time of other messages.

Performance Evaluation of IPv4/IPv6 Transition Mechanisms for Real-Time Applications using OPNET Modeler

The problem of the potential depletion of IPv4 addresses has given rise to the development of a new version of the Internet Protocol named IPv6. This version of the protocol offers many improvements, including an increase in the address space from 232 to 2128 and improvements in security, mobility, and quality of service. However, the transition from the current version to the new version (IPv4 to IPv6) is complicated and cannot be performed in a short time. The size and complexity of Internet make this migration task extremely difficult and time-consuming. The Internet Engineering Task Force (IETF) took into account this migration problem and proposed transition mechanisms as temporary solutions allowing IPv4 to coexist and operate in parallel with IPv6 networks. The dual stack, manual tunnel, and 6to4 automatic tunnel appear to be promising solutions depending on their characteristics and benefits. In this paper, we study the performance of these transition mechanisms on real-time applications (VoIP and Video Conferencing) using the network simulator OPNET Modeler. Performance parameters such as delay, delay variation, jitter, MOS, and packet loss are measured for these transition mechanisms. The obtained results showed that the dual stack transition mechanism gave better network performance than the tunneling mechanisms.

Computer-Aided Drug Design for NS5 Protein of Zika Virus

Abstract In the competition of this modern technology the aim of Mobile Ad-Hoc networking is to provide efficient communication in wireless technology by adopting routing functionality in mobile nodes. The main aim behind the developing of ad hoc networking is multi-hop relaying. Wireless Ad hoc networks or infrastructure less networks are very easy to establish by using radio waves as transmitting medium without the requirements of any other equipment or infrastructure. In such a network mobile nodes can be moved and organized freely in an arbitrary way. This dynamic connectivity of nodes allow mobile ad hoc network to be organized any where any time. Loads of research work and efforts have been done since last decade to provide support and solution to different problems and challenges related to mobile ad hoc networks. But still the fast growing technology needs attention in many areas such as routing, bandwidth, security, power consumption, collisions, simulations, and topology control due to moving nodes especially for achieving 4 generation environment and resulting best QOS’s. Sprint offers a 3G/4G connection plan, currently available in select cities in the United States. It delivers rates up to 10 Mbit/s. I have proposed three routing protocols (DSR, AODV, TORA) with different range, frequencies and parameters towards the contribution for best performance towards 4 generation cellular networks with an extension of ad hoc networks through a gateway i-e wireless routers or iphone etc. This has a very good contribution using OPNET simulator for best results on Real Time basis towards 4G cellular networks.

Signaling and Scheduling WIMAX Gateway Design Based on Resource Reservation Protocol

Objectives: As a result of signal transmission in WiMAX too long distance, and because there are many request packets arrive at WiMAX gateway request handovers, this cost a congestion which may result in loss or delay in packet time sensitive. The objectives of this paper are to investigate the delay when packets with real time sensitive handover in WiMAX gateway and to measure and enhance the handover performance. Methods/Statistical Analysis: To overcome this problem, and achieve the objectives is propose a new scheme Resource Reservation Protocol & Random Early Detection with Weighted Fair Queuing (RR-WFQ) in order to analyze and enhance delay for real time packet in WiMAX gateway. This schema applies all Resource Reservation Protocol (RSVP), Random Early Detection (RED), and Weighted Fair Queuing (WFQ) as a Scheduling, RED as a mechanism and RSVP as a signaling protocol. Findings: The proposed scheme enhances the QoS by minimizing the delay in WiMAX gateway and BS. The scheme enhances the delay in all queues in a gateway, and video conferencing. The result of the scheme shows an enhancement delay in the WiMAX gateway. Application/Improvements: Mathematical analysis and modeling have been done using queuing theory. Simulation has been done using OPNET simulation. Simulation results for the new approach confirms that has minimized delay in WiMAX gateway and BS the gateway and enhances the QoS.

Design and performance analysis of a full-duplex MAC protocol for wireless local area networks

In this paper, Synchronized Contention Window Full-Duplex (S-CW FD) protocol is presented as a medium access control (MAC) protocol that enables full-duplex (FD) in wireless local area networks (WLANs), while seamlessly operating together with legacy nodes. For performance analysis, a Markov chain model of S-CW FD is devised, using this model, the saturated throughput of S-CW FD is derived and the results are validated by comparisons with OPNET simulations. Later, through detailed simulations, S-CW FD is evaluated against standard half-duplex IEEE 802.11, considering realistic self-interference and channel models and the effect of hidden nodes. It is shown that S-CW FD MAC protocol can double the throughput of standard half duplex IEEE 802.11 without hidden nodes in the network, and its improvement can get as high as ten fold in the presence of hidden nodes. In this work, S-CW FD is also compared to two similar contention based FD MAC protocols from the literature, and it is shown that, under typical network loads, S-CW FD outperforms those protocols by up to 30%, despite much lower complexity. Overall, S-CW FD stands out as a promising candidate for implementing FD in WLANs due to significant performance improvements, simplicity and flexibility for application in different FD modes to support bidirectional, relaying and cellular scenarios.

A Performance Evaluation of IEEE 802.15.4 Based on Wireless Sensor Network for Small-Scale Application

This paper evaluates the performance of IEEE 802.15.4 standard Wireless Sensor Networks (WSN) in star topology of small scale applications. The performance of the network is analyzed in terms of end to end delay, maximum throughput and number of network devices with respect to the payload. This analysis which is devoted for biomedical applications is performed theoretically and compared with a practical analysis using the network simulator Opnet modeler (version 14.5) in order to validate this theoretical analysis.