Parag Kumar Guha Thakurta

Effect of optimal cluster head placement in MANET through multi objective GA

Ad-hoc network refers to a wireless network comprising of non-stationary nodes, which autonomously collaborate between themselves for transmitting communication. Wireless sensor networks (WSN) are a subclass, where the nodes feature topological limitation in creating contact with the outside world. Replenishment of energy in WSN is usually not possible due to inhospitable environment. Accordingly, activity switching and clustering are two major approaches adopted for energy conservation and prolonging lifetime in MANETs. For large networks, soft computing has been repeatedly proven to achieve near to optimal solutions in routing and clustering problems. A genetic algorithm based approach towards efficient election of cluster heads has been proposed. The objective functions targeting optimal selection and placement of cluster centers has been derived. The problem is genetically encoded and standard multi-objective genetic algorithm is used for evaluation. Subsequent results and comparative discussion is provided.

Multi Objective Optimization on Clustered Mobile Networks: An ACO Based Approach

Clustering technique transforms a physical network into a virtual one to obtain an improved Quality of service (QoS). Addressing this issue, a multi objective optimization (MOO) on QoS metrics for clustered mobile networks is proposed in this paper. A simultaneous optimization is done by minimizing the number of cluster heads (CHs) to reduce delay in routing call requests as well as maximizing the number of cluster members under a CH such that network coverage is improved. This is obtained through a proposed ant colony optimization (ACO) based routing algorithm followed by a checking procedure on network status to detect emergence of CHs and correctness of subsequent routing. The effectiveness of the proposed approach over existing one is shown with simulation studies.

An Efficient Approach for Detecting Wormhole Attacks in AODV Routing Protocol

In MANET, wormhole link creates an illusion in such a way that two remote regions are directly connected through nodes which seems to be neighbors; however, these are actually distant from one another. The attackers using wormhole can easily manipulate the routing priority in AODV to perform eavesdropping, packet modification, or packet drop. Hence, a two-phase wormhole link detection procedure in AODV routing protocol is proposed to identify the malicious link for avoiding such erroneous transmission. Initially, the round trip time (RTT) and corresponding round trip bit transfer (RTBT) of each link are determined. Here, if RTBT of any link is greater than a dynamic threshold value (RTBTTH), then such victim link is marked as a suspicious link. Next, the amount of power required to send a packet of certain size by each node is obtained to verify whether the transmission power of suspected links is reasonably high compared to other links. Various experimental results are carried out to validate the proposed work as well as to show an improvement obtained by the proposed approach in terms of several performance metrics.

An Approach Towards Energy Efficient Channel Reduction in Cellular Networks

An energy efficient model in cellular networks is proposed in this paper to reduce the number of long range channels as well as the energy consumption of the mobile devices. The devices having high energy in terms of battery level are used to establish communication between the base station and the requesting mobile devices. The overall energy consumed by all devices is estimated if one such high energy device receives data from the base station and subsequently propagates the same to other mobile devices. The energy consumption is assessed for increasing number of bridging devices. The proposed approach reduces the number of long range channels used and the overall energy consumption of devices. The experimental results show the effectiveness of the proposed approach.

An approach towards identification of malicious nodes in mobile ad hoc networks

Mobile nodes depend upon mutual operation to perform data transmission in an ad hoc network. In absence of central controlling authority, the authenticity of individual nodes plays an important role. Nodes depend upon a mutual understanding for deciding the malfunctioning of any member. The reliability of this decision is vital for forwarding data within the network. Before applying any standard routing protocol, an efficient network partitioning between the reliable and malfunctioning is thus necessary. This has been approached in this work. The success rate and fault tolerance of the approach has also been discussed.

Joint routing in mobile networks: a weighted optimization approach

Abstract In the era of mobile communications, the need for resource-demanding services has drastically increased. To meet the quality of service requirements and to utilize resources in spite of scarcity, a priority-based scheduler featuring joint routing scheme for mobile networks is proposed in this paper. This scheme takes into account, the role of priority in a more comprehensive manner. The scheduler routes every call request optimally, pertaining to various constraints, while simultaneously improving the call acceptance for the system. The proposed scheme provides an optimal route through a weighted optimization method based upon the various factors. The performance of the proposed model is assessed and evaluated with different parameters through simulation studies.

A new hybrid channel allocation scheme for mobile networks: Markov chain representation

In mobile communication systems, the efficient use of available channels has been shown to improve the system capacity against limited resource. The role of a channel assignment scheme is to allocate channels to cells or mobiles in such a way that the communication facility is improved. In this context, a new approach on hybrid channel allocation scheme (HCA) for mobile networks is proposed in this paper. It includes the features of both fixed channel allocation (FCA) and dynamic channel allocation (DCA) schemes. The assigned channels through FCA are equally distributed among each of the side of a hexagonal cell under a base station (BS) for low traffic. The DCA is proposed for further improvement by introducing dynamic allocation policy. The intercellular channel allocation (ICA) phase describes call scheduling procedure. In addition, the proposed model is verified through Markov Chain representation. The characteristics of the proposed model are expressed with Markov Chain process. The proposed model achieves an improved performance in terms of reduced communication and computational overhead.