Network

Wireless Sensor Networks are used in numerous security sensitive applications, it composed of a huge number of resource limited sensors therefore we should make sure the network is secured against security attacks. Denial of service attack in WSNs is a serious attack that reduces the network capacity dramatically and the users fail to receive expected service. Many schemes have been proposed to tolerate or destroy DoS attack, but very few can identify intruders and provide security against this attack. In this paper, we explore the effects of DoS in WSN, effective security methods for achieving the security against this attack. Finally two important types of DoS attacks called jamming and reply attack are studied and possible solutions are recommended.

Since the introduction of Automated Teller Machines (ATMs) in Nigeria, cash handling has really reduced especially for those who live in the city and have easy access to ATM machines by means of their ATM cards. People no longer see the needs to carry excess cash at home when they already have an ATM card since ATM machines can be easily accessible. ATM operation did not turn out to be all rosy as it started out. This research surveys ATM malfunctions in four states in Nigeria to ascertain the nature of malfunction that is prevalent and formulates a modification algorithm/routine that should possibly correct this ATM misfit.

This paper proposes a distributed Quality of Service (QoS) oriented routing algorithm for hybrid wireless network. The wireless applications are demanding robust networks with end to end QoS requirements. Hybrid wireless networks will be the best next generation network. So providing QoS routing algorithm for such networks is on demand research. Here the QoS-Oriented Distributed routing protocol (QOD) is proposed to enhance the QoS support of hybrid wireless networks. This protocol consists of 6 algorithms. 1. Neighbor selection algorithm 2. Malicious Node Detection 3.Packet scheduling 4. Node mobility speed based packet assigning, 5. Packet data compression deflate algorithm 6.Tra?c redundancy elimination algorithm. The simulation results show that packet delay, packet loss is getting improved.

In Wireless Sensor Networks, having two types of approaches non-clustering & clustering based. In both cases the prime role in network is energy consumption to transmit the data that will decide the life time of network. So this paper focused on the energy consumption. This research paper works for generation or formation of cluster & how to select the cluster head by which consideration of energy consumption should be less than non-clustering approach. In this research paper to create the cluster, implement the K-Mean algorithm to select the cluster head based on the nearest node to the location of center of cluster. This paper considers the sending energy consumption of each node in the whole network in both cases i.e. non-clustering & clustering.

Numerous schemes have been proposed for secure routing and Intrusion Detection for ad hoc net- works. Yet, little work exists in actually implementing such schemes on small handheld devices. In this paper, we present a proof-of-concept implementation of a secure rout- ing protocol based on AODV over IPv6, further reinforced by a routing protocol independent Intrusion Detection System (IDS) for ad hoc networks. Security features in the routing protocol include mechanisms for non-repudiation and authentication, without relying on the availability of a Certificate Authority (CA) or a Key Distribution Center (KDC). We present the design and implementation details of our system, the practical considerations involved, and how these mechanisms can be used to detect and thwart malicious attacks. We discuss several scenarios where the secure routing and intrusion detection mechanisms isolate and deny network resources to nodes deemed malicious.

In this paper, a distance based Cluster head selection algorithm is proposed for improving the sensor network life time. This protocol achieves a good performance in terms of lifetime by balancing the energy load among all the nodes. This clustering technique help to prolong the life of wireless sensor network, especially in hostile environment where battery replacement of individual sensor nodes is not possible after their deployment in the given target area. Therefore, the proposed technique to distribute the role of the cluster head (CH) among the wireless sensor nodes in the same cluster is vital to increase the lifetime of the network. This algorithm uses a distance based method for providing the cluster head selection. Clustering techniques also provide good load balancing. This paper based on the distance of nodes and elects the cluster head to be responsible collects the data from nodes, this implementation done in c- Language.

In today`s global scenario the demand of Wireless communication service is growing rapidly. In order to serve a high user population in a limited spectrum, using dense grids of microcells and picocells is one of possible schemes. While small cells relieve the capacity problem, frequent movements of mobile users across cell boundaries pose a big network control challenge: handover In personal communication networks (PCN) supporting network-wide handovers, new and handoff requests compete for connection resources in both mobile and backbone networks. Due to limited range of transceivers, mobile users can communicate only with base station that reside within the same microcell at any instant of time. The number of handovers during a call will increase, as the cell radii decreases, thus affecting Quality of Service (QoS). As the handoff rate increases, bandwidth management and traffic control strategy (call admission control, handover procedures etc) become more challenging problems in wireless ATM networks. Thus in a wireless environment, we need to consider two additional QoS parameters; dropping probability of handoff calls and blocking probability of new calls. Handoff calls require a higher congestion related performance i.e., blocking probability relative to new calls because forced call terminations due to handoff call blocking are generally more objectionable than new call blocking. In general, most of the previously proposed schemes for radio channel allocation in cellular networks reduce handoff call blocking probability substantially at the expense of increasing the new call blocking probability by giving higher priority to handoff calls over new calls in admission control. This reduces the total admitted traffic and results in inefficient utilization of wireless channels. The tradeoff between the new and handoff calls blocking probabilities should be defined. In this paper, a modified Hybrid scheme has been proposed for handover in ATM-based PCN, which combines reservation and queuing schemes for handoff calls. Also , the scheme assigns the handoff reserved channels to new calls depending on the locality principle in which the base station with the help of location estimation algorithm in the mobile location centre predicts the position of the mobile terminal. Here the FIFO and Measurement Based Priority Scheme (MBPS)queuing scheme are used. Thus the modified Hybrid Scheme is designed to have a remarkable reduction in forced termination Probability (FTP) along with to improve channel utilization while satisfying the QoS of the calls.

In Wireless Sensor Networks, cluster head is the key technology where nodes or motes the information transmit it to the base station. The energy consumption in a wireless sensor network can be reduced by allowing only some nodes to communicate with the base station. One way to support efficient communication between sensors is to organize the network into multiple groups, called clusters, with each cluster electing one node as the head of cluster. To support scalability, nodes are often grouped mostly non-overlapping clusters. This paper proposes a new design of an efficient clustering in wireless sensor head which is based on two level clustering. In two levels clustering approach instead of sensor nodes sends the data to cluster heads directly, each node sends data to their cluster head and then sends data to the base station.

A survey on mobile adhoc network networks have experienced strong growth due to their ability to provide an additional and complementary support for existing infrastructure communication systems. In such a network, routers are supposed to be fixed for short (e.g. public safety deployment) or long (e.g. network operator extension) period. This relative stability of infrastructure makes proactive routing protocols appropriate. One of the well known proactive routing protocols is OLSR (Optimized Link State Routing), which routing decisions are based on exchanges of topology information using all-to-all flooding of local information in order for each router to build a global knowledge of the topology. This study first goal is to improve the performance of topology information flooding in OLSR by introducing network coding techniques, which leads to a decrease of signaling overhead.

Turbo codes are one of the most powerful error correcting codes. In this paper focus is made on Bit Error Rate (BER) performance analysis of MAP, Log MAP and Max Log MAP turbo decoding algorithms in wireless AWGN channels. The research is investigated in several aspects to evaluate the performance of turbo codes in AWGN channel with different Signal to Noise Ratio (SNR), different generator polynomials and for different constraint lengths. The simulation results give some demonstrations that are valuable for the applications of turbo codes in AWGN channel with different SNRs.