Mobile Ad hoc Network (MANET) is a kind of wireless ad-hoc network, and is a self-configuring network of mobile routers (and associated hosts) connected by wireless links – the union of which forms an arbitrary topology. The routers are free to move randomly and organize themselves arbitrarily, thus the network's wireless topology may change rapidly and unpredictably. Such a network may operate in a standalone fashion, or may be connected to the larger Internet. There are various routing protocols available for MANETs. The most popular ones are DSR, AODV and DSDV. This paper examines two routing protocols for mobile ad hoc networks– the Destination Sequenced Distance Vector (DSDV and the Ad hoc On- Demand Distance Vector routing (AODV). Generally, the routing algorithms can be classified into Reactive and Proactive. A Hybrid algorithm combines the basic properties of reactive and proactive into one. The proposed approach is a novel routing pattern based on Ant Colony Optimization and Multi Agent System. This pattern integrates two different algorithms together and helps to get optimum routes for a particular radio range. The approaches used here are Ant Colony Optimization (ACO) and Multi Agent System (MAS). The proposed integrated approach has a relatively short route establishment time while using a small number of control messages which makes it a scalable routing approach. The overhead of this routing approach will be inexpensive and also will enable to have an alternate route during route failure. This proposed route finding scheme in order to provide high connectivity of nodes, will minimize the route discovery latency and the end-to-end delay.

As wireless networks access gains popularity in corporate, private and personal networks, the nature of wireless networks opens up new possibilities for network attacks. This paper negotiating Wi-Fi security against scanning of rogue Wi-Fi networks and other related activities and considers the monitoring of Wi-Fi traffic effects. The unauthorized access point (AP) problem has raised more attention and resulted in obtaining wireless access without subscriber permission.
This work assumes Wi-Fi AP under attack specially rogue AP and/or ad-hoc client. It provides a solution for detecting and preventing this attack. In addition, it provides the required user permissions to allow/block access of the files on the user of ad-hoc client. The experiments include the rogue AP attack are maintained and the effectiveness of the proposed solution are tested.

In this paper, a chaotic image encryption scheme with an efficient permutation–diffusion mechanism is constructed, where six generalized Bernoulli shift maps and one six-dimensional Arnold map are utilized to generate one hybrid chaotic orbit applied to disorder the pixel positions in the permutation process while four generalized Bernoulli shift maps and one Arnold map are employed to yield two random gray value sequences to change the gray values by a two-way diffusion process. Several merits of the proposed image encryption scheme are achieved, including a huge key space, good statistical properties resisting statistical attack and differential attack, desirable robustness against malicious attacks on cipher-images, such as cropping, noising, JPEG compression, etc. Experimental results have been carried out with detailed analysis to show that the proposed scheme can be a potential candidate for practical image encryption.

The communication range of devices within a mobile ad hoc network is inherently restricted. One way of enhancing the communication range of a mobile ad hoc network, is to interconnect it to a wired network like the internet, thus forming a heterogeneous wired cum wireless network. This interconnection also enables mobile nodes to access internet services, and is achieved through gateways. Mobile nodes in the ad hoc network need to discover and register with a gateway in order to obtain Internet connectivity. Gateway discovery mechanisms called proactive, reactive and hybrid exist to enable mobile nodes to register with internet gateways. In the recent times, few optimizations have been proposed to the existing gateway discovery mechanisms in order to make gateway discovery by mobile nodes efficient. In this paper, we present a detailed survey of the state of the art in gateway discovery and selection mechanisms.

Privacy is one of the key issues information Security addresses. Through encryption one can prevent a third party from understanding raw data during signal transmission. The encryption methods for enhancing the security of digital contents has gained high significance in the current era of breach of security and misuse of the confidential information intercepted and misused by the unauthorized parties.
This paper sets out to contribute to the general body of knowledge in the area of cryptography application and by developing a cipher algorithm for image encryption of m*n size by shuffling the RGB pixel values. The algorithm ultimately makes it possible for encryption and decryption of the images based on the RGB pixel. The algorithm was implemented using MATLAB.

In this paper, a new design for ring-shaped cells is introduced where to improve the power distribution and carrier-to-interference ratio (CIR) over the cell area. The designed cell has flat-top radiation pattern with minimal ripples in the service area while the out-of-cell area has lower radiation levels. The new design utilizes two weighting functions applied to a vertical linear array; the first is responsible for the flat-top design and the second smoothes the pattern and reduces the sidelobe levels. The resulted power pattern has a uniform distribution over the cell stripe with as small as 0.25 dB ripples and a uniform CIR values greater than 43 dB within the cells which reduces the burden of power control and increases the immunity to propagation problems.

This paper presents Adaptive Population Sizing Genetic Algorithm (AGA) assisted Maximum Likelihood (ML) estimation of Orthogonal Frequency Division Multiplexing (OFDM) symbols in the presence of Nonlinear Distortions. The proposed algorithm is simulated in MATLAB and compared with existing estimation algorithms such as iterative DAR, decision feedback clipping removal, iteration decoder, Genetic Algorithm (GA) assisted ML estimation and theoretical ML estimation. Simulation results proved that the performance of the proposed AGA assisted ML estimation algorithm is superior compared with the existing estimation algorithms. Further the computational complexity of GA assisted ML estimation increases with increase in number of generations or/and size of population, in the proposed AGA assisted ML estimation algorithm the population size is adaptive and depends on the best fitness. The population size in GA assisted ML estimation is fixed and sufficiently higher size of population is taken to ensure good performance of the algorithm but in proposed AGA assisted ML estimation algorithm the size of population changes as per requirement in an adaptive manner thus reducing the complexity of the algorithm.

The data aggregation is a widely used energy-efficient mechanism in wireless sensor Networks (WSNs), by avoiding the redundant data transmitting to base station. The deployment of wireless communicating sensor nodes in the hostile or unattended environment causes attack more easily and the resource limited characteristics make the conventional security algorithms infeasible, hence protecting privacy and integrity during data aggregation is a challenging task. The privacy of a sensor data ensures, it is known only to itself and the integrity guarantees sensor data has not tampered during data aggregation. The Integrity Protecting Privacy preserving Data Aggregation (IPPDA) protocols ensures a robust and accurate results at the base station. This paper summarises on such IPPDA protocols during data aggregation.