Network

In Wireless sensor networks the major concern is how to conserve the nodes' energy so that network lifetime can be extended significantly. Employing one static sink can rapidly exhaust the energy of sink neighbors. Furthermore, using a non-optimal single path together with a maximum transmission power level may quickly deplete the energy of individual nodes on the route. This all results in unbalanced energy consumption through the sensor field, and hence a negative effect on the network lifetime. In this paper, we present a comprehensive taxonomy of the various mechanisms applied for increasing the network lifetime. These techniques, whether in the routing or cross-layer area, fall within the following types: multi-sink, mobile sink, multi-path, power control and bio-inspired algorithms, depending on the protocol operation. In this taxonomy, special attention has been devoted to the multi-sink, power control and bio-inspired algorithms, which have not yet received much consideration in the literature. Moreover, each class covers a variety of the state-of-the-art protocols, which should provide ideas for potential future works. Finally, we compare these mechanisms and discuss open research issues.

An access control mechanism in a user hierarchy is used to provide the management of sensitive information for authorized users. The users and their own information can be organized into a number of disjoint sets of security classes according to their responsibilities. Each security class in a user hierarchy is assigned an encryption key and can derive the encryption keys of all lower security classes according to predefined partially ordered relation. In 2006, Jeng and Wang proposed an efficient key management scheme based on elliptic curve cryptosystems. This paper, however, pointed out that Jeng–Wang scheme is vulnerable to the so-called compromising attack that the secret keys of some security classes can be compromised by any adversary if some public information modified. We further proposed a secure key management scheme based on elliptic curve cryptosystems to eliminate the pointed out the security leak and provide better security requirements. As compared with Jeng and Wang’s scheme (Jeng and Wang, 2006), the proposed scheme has the following properties. (i) It is simple to execute the key generation and key derivation phases. (ii) It is easily to address dynamic access control when a security class is added into or deleted from the hierarchy. (iii) It is secure against some potential attacks. (iv) The required storage of the public/secret parameters is constant.

This work proposes a methodology for QoS improvement in MANET based on Medium Access Control (MAC) protocol that takes the above requirements into consideration. This protocol is based on IEEE 802.11 standard, and thus can be easily integrated into existing systems without much difficulty. Here 802.11 and 802.11e with different TCP mechanisms are used to analyze the QoS parameters for MANETs. The proposed system is designed to evaluate the performance of QoS and interaction between Transport layer and the MAC layer protocol operating in a mobile ad hoc network. The system will makes use of IEEE 802.11e MAC mechanism, to improve quality of service in MAC layer, which will improve the quality of service in Transport layer and to suggest a suitable mechanism for improving the quality of service in MANETs.

A reliable multicast routing enables a process to multicast a message to a group of clients in a way that ensures all the host destination group members receive the same message. Multicast routing on Wireless Mesh Networks brings great challenges in security due to its high dynamics, link vulnerability, and complete decentralization. Hence, due to its insufficient security requirements and vulnerability to attacks, a novel secure multicast routing protocol S-ODMRP, takes full advantage of trusted computing technology. The novel methods proposed overcomes the above degradation and decreases the communication cost by broadcasting the local traffic and by providing self healing mechanism to each nodes in the network so that it cures the link failure caused by the failed routers and reconstructs the multicast key path, in which the path selection is based on the link basis. And the trusted key is distributed for the secure multicast routing in the Wireless Mesh Networks. In which the trust value for each node is based on some set of rules such as the jointly behaviors, energy behaviors, and the activity model. Hence the NS-2 simulation includes various parameters such as Packet Delivery Ratio (PDR), Bandwidth overhead, cost per received packet, number of attackers and achieves the higher security and throughput.

To solve the problems in environmental monitoring arising from remote data acquisition, real-time transmission and analysis, this paper researched the principle of wireless communications SMS / GPRS and the technology of seamless integration with GIS. The system architecture was designed and key technical solutions were implemented. Based on the SMS / GPRS technology, the wireless real-time transmission of the remote monitoring data was achieved, and GIS visualization technology was carried out to visualize the monitoring data. Geographic affected areas were analyzed by GIS spatial analysis. The system is applicable to the environmental protection departments to realize applications such as monitor data acquisition, communication transmission, GIS management and analysis and decision-making.

Power consumption of system level on chip communications is becoming more significant in the overall system on chip power as technology scales down. High bandwidth is desired to enhance parallelism for better performance, and the power efficiency on this bandwidth is critical to the overall SoC power consumption. Current bus architectures such as AMBA, Core connect, and Avalon are convenient for designers but not efficient on power. This paper proposes a physical synthesis scheme for on chip buses and bus matrices to minimize the power consumption, without changing the interface or arbitration protocols. By using a bus gating technique, data transactions can take shortest paths on chip, reducing the power consumption of bus wires to minimal. Routing resource and bandwidth capacity are also optimized by the construction of a shortest-path Steiner graph, wire sharing among multiple data transactions, and wire reduction heuristics on the Steiner graph. In this paper, we optimize on-chip bus communications on the tradeoffs between minimal power, maximal bandwidth, and minimal total wire length. Based on AMBA protocols, we modify the bus structure using a “bus gating” technique, and apply optimizations which are biased toward minimal power, but also favor bandwidth and routing resource.

Cloud computing is one of the emerging technologies that will lead to the next generation of Internet. It provides optimized and efficient computing through enhanced collaboration, agility, scalability, and availability. In this paper, the evolution of the Cloud is discussed, the cloud computing model is explained, a set of cloud computing infrastructure metrics is listed, the cloud service model architectures are described, exemplary implementations of cloud service models are analyzed, and intriguing facts about cloud computing status and future are shared.

Today in the world of computer networking, wireless networks are becoming one of the most popular, valuable, decisive & critical medium for communication. Among the wireless networks, MANET’s i.e., Mobile Ad-hoc Networks are of their own importance. For the purpose of group communication, there are many applications of MANET’s in the areas like as an automated battlefields, crowd control, disaster recovery, conference, search and rescue operations etc. An Ad-hoc Network is basically a wireless network comprising a set of mobile nodes in absence of any centralized access point or fixed infrastructure.In this paper, the necessary parameters which are required to characterize the MANET’s have been presented. A kind of review is done upon these important parameters. The various parameters responsible for the routing strategies in MANETs are the parameters like as performance analysis, reliability, scalability, power saving, efficiency as well as security.By depicting these essential parameters for MANETs, we are able to make proper as well as efficient utilization of MANETs in various fields of communication such as conferencing, pollution monitoring, emergency services like battlefield, disaster recovery, vehicular networks, etc.

In a mobile ad hoc network, the mobility and resource constraints of mobile nodes may lead to network partitioning or performance degradation. Several data replication techniques have been proposed to minimize performance degradation. Most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. In reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These selfish nodes could then reduce the overall data accessibility in the network. In this paper, the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation is examined. A selfish node detection algorithm was developed that considers partial selfishness and novel replica allocation techniques to properly cope with selfish replica allocation. The conducted simulations demonstrate the proposed approach outperforms traditional cooperative replica allocation techniques in terms of data accessibility, communication cost and average query delay.

To provide an efficient facility to reserve the human resource appropriately, many aids has been proposed and thus one the measure used recently is sensor nodes with the efficient technology of android system with most available resource that is mobile phones which facilitates each person with security of their healthcare efficiently. As most common feature provided by smart phones is about alerting any person about any situation, this benefit is been utilized in medical healthcare system to provide one of the most important facility to preserve people’s wealth of health.