Mrinal Kanti Naskar

A trust based clustering with Ant Colony Routing in VANET

Inter-vehicle communication is a promising way to share and disseminate real-time and nearby safety information on the road. Scalability of vehicular ad hoc network is one of the decisive matters for a network designer, which can be solved by clustering. In this paper, as our first algorithm an attempt has been made to create clusters by considering direction, position and relative speed of the vehicle for managing the scalability issue. Moreover, we have proposed a new algorithm for selecting the most appropriate cluster head (CH) by considering the real time updated position and trust value of vehicles. As, evolutionary based routing is a predominant research theme thus we have used the most efficient ant colony routing technique based on trust for the simple highway scenario based VANET. Finally simulation result shows our proposed Trust dependent Ant Colony Routing (TACR) has outperformed the Mobility-aware Ant Colony Optimization Routing (MAR-DYMO) algorithm in terms of routing overhead.

A Direct Trust Dependent Link State Routing Protocol Using Route Trusts for WSNs (DTLSRP)

The traditional cryptographic security techniques are not sufficient for secure routing of message from source to destination in Wireless Sensor Networks (WSNs), because it requires sophisticated software, hardware, large memory, high processing speed and communication bandwidth. It is not economic and feasible because, depending on the application, WSN nodes are high-volume in number (hence, limited resources at each node), deployment area may be hazardous, unattended and/or hostile and sometimes dangerous. As WSNs are characterized by severely constrained resources and requirement to operate in an ad-hoc manner, security functionality implementation to protect nodes from adversary forces and secure routing of message from source node to base station has become a challenging task. In this paper, we present a direct trust dependent link state routing using route trusts which protects WSNs against routing attacks by eliminating the un-trusted nodes before making routes and finding best trustworthy route among them. We compare our work with the most prevalent routing protocols and show its benefits over them.

Geometric mean based trust management system for WSNs (GMTMS)

The Wireless Sensor Network (WSN) nodes are high-volume in number, and their deployment environment may be hazardous, unattended and/or hostile and sometimes dangerous. The traditional cryptographic and security mechanisms in WSNs cannot detect the node physical capture, and due to the malicious or selfish nodes even total breakdown of network may take place. Also, the traditional security mechanisms in WSNs requires sophisticated software, hardware, large memory, high processing speed and communication bandwidth at node. Hence, they are not sufficient for secure routing of message from source to destination in WSNs. Alternatively, trust management schemes consist a powerful tool for the detection of unexpected node behaviours (either faulty or malicious). In this paper, we propose a new geometric mean based trust management system by evaluating direct trust from the QoS characteristics (trust metrics) and indirect trust from recommendations by neighbour nodes, which allows for trusted nodes only to participate in routing.

A New Method for Fast and Low Cost Handover in Leo Satellites

Now-a-days LEO satellites have an important role in global communication system. They have some advantages over GEO & MEO satellites such as power requirement and endto-end delay is lower and it has more efficient frequency spectrum utilization between satellites and spotbeams. So in future they can be used as a replacement of modern terrestrial wireless networks. But they main problem of LEO satellites is that they have large relative speed than the speed of mobile nodes (MN) & earth. That’s why the handover occurrence is more. So the call blocking probability (Pb) and force call termination probability (Pf) is also higher. To overcome this problem several handover techniques is proposed. Here we propose Billboard Manager based handover (BMBHO) technique using the concept of Billboard Manager (BM) proposed by Aysegul et al in 2006 but in a different way. Here we reduce the scanning time significantly. Also the cost is reduced. Here we also describe how to reduce (Pf). In this paper you will find a set of simulations both for our proposed method & standard handover methods. We can find that this method is very useful by the simulation results.

Genetic evolutionary algorithm for optimal allocation of wavelength converters in WDM optical networks

In this article, a genetic evolutionary algorithm is proposed for efficient allocation of wavelength converters in WDM optical networks. Since wavelength converters are expensive, it is desirable that each node in WDM optical networks uses a minimum number of wavelength converters to achieve a near-ideal performance. The searching capability of genetic evolutionary algorithm has been exploited for this purpose. The distinguished feature of the proposed approach lies in handling the conflicting circumstances during allocation of wavelength converters considering various practical aspects (e.g., spatial problem, connectivity of a node with other nodes) rather than arbitrarily to possibly improve the overall blocking performance of WDM optical networks. The proposed algorithm is compared with a previous approach to establish its effectiveness and the results demonstrate the ability of the proposed algorithm to efficiently solve the problem of Optimal Wavelength Converters Allocation (OWCA) in practical WDM optical networks.

Balancing Energy Dissipation in Data Gathering Wireless Sensor Networks Using Ant Colony Optimization

Formulation of energy efficient protocols is of utmost importance for wireless sensor networks because of energy constraints of sensor nodes. When a number of nodes is deployed in a field located away from the base station, the nodes undergo unequal energy dissipation while transmitting information to the base station primarily due to two reasons: i) the difference in the distances of nodes from the base station and ii) the variation in inter-nodal distances. The schemes presented here better network lifetime by taking into account these two issues and try to equalize the energy dissipation by the nodes. While constructing the chain we also use Ant Colony Optimization algorithm instead of greedy approach used in PEGASIS. Application of ACO ensures that the chain formed is of shortest possible length and thus further helps enhance network performances by reducing the inter-nodal transmission distances as much as possible. Extensive simulations performed corroborates that the proposed schemes outperform PEGASIS by a significant margin.

Genetic evolutionary algorithm for static traffic grooming to SONET over WDM optical networks

In recent years, minimization of SONET-ADMs (Synchronous Optical NETwork-Add-Drop Multiplexers) in WDM (Wavelength Division Multiplexing) optical networks has gained a lot of attention in both the research and commercial arenas. This motivates the research presented in this article. The enhanced searching capability of genetic evolutionary algorithm has been exploited for this purpose. The individuals (chromosomes) have been represented by different sequence of the calls in the traffic matrix. A simple algorithm that minimizes the number of required ADMs based on the shortest path and a possible alternate shortest path has been applied. Some good chromosomes based on some intuitive reasoning have been introduced in the initial population to enhance the convergence of the proposed genetic evolutionary algorithm. The distinguished feature of the proposed algorithm is in introducing the catalyst to direct the convergence of genetic evolutionary algorithm towards its solution. However, the catalyst has been kept small enough to be able to bias the solution. To establish the effectiveness of the proposed algorithm, the simulation results are compared with that of presented in literature with same network configuration and traffic matrix.

Minimization of Handoff Failure Probability for Next-Generation Wireless Systems

During the past few years, advances in mobile communication theory have enabled the development and deployment of different wireless technologies, complementary to each other. Hence, their integration can realize a unified wireless system that has the best features of the individual networks. Next-Generation Wireless Systems (NGWS) integrate different wireless systems, each of which is optimized for some specific services and coverage area to provide ubiquitous communications to the mobile users. In this paper, we propose to enhance the handoff performance of mobile IP in wireless IP networks by reducing the false handoff probability in the NGWS handoff management protocol. Based on the information of false handoff probability, we analyze its effect on mobile speed and handoff signaling delay.

An Optimized Lifetime Enhancement scheme for data gathering in wireless sensor networks

Design of energy efficient schemes for data gathering is an important concern for lifetime enhancement of wireless sensor networks. Variation in the distances of nodes from the Base Station and differences in inter-nodal distances are primary factors causing unequal energy dissipation among the nodes. Thus energy difference between the various nodes increases with time resulting in degraded network performance. The LEACH and PEGASIS schemes which provided elegant solutions to the problem suffer basic drawbacks due to randomization of cluster heads and greedy chain formation respectively. In this paper, we propose an Optimized Lifetime Enhancement (OLE) Scheme which shows enhanced performance over these schemes. OLE increases the network performance by ensuring a sub-optimal energy dissipation of the individual nodes despite their random deployment. It employs modern heuristics like particle swarm optimization instead of the greedy algorithm as in PEGASIS to construct energy efficient routing paths. Extensive simulations validate the improved performance of OLE.

Adaptive dynamic wavelength routing for WDM optical networks

In this article, an efficient heuristic approach for routing and wavelength assignment (RWA) in WDM optical networks is proposed. The method is based on the selection of shortest path or alternate shortest path depending on the number of overlaps of a new route with the non-terminated calls. Comparative studies with the previous work demonstrate the superiority of the proposed algorithm