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Data replication is a known redundancy used in fault-tolerant distributed system. However, it has the problem of mutual exclusion of replicated data. Mutual exclusion becomes difficult when a distributed system is partitioned into two or more isolated groups of sites. In this study, a new dynamic algorithm is presented as a solution for mutual exclusion in partitioned distributed systems. The correctness of the algorithm is proven, and simulation is utilized for availability analysis. Simulations show that the new algorithm, ancestral dynamic voting algorithm, improves the availability and lifetime of service in faulty environments, regardless of the number of sites and topology of the system. This algorithm also prolongs the lifetime of service to mutual exclusion for full and partial topologies especially for the situations where there is no majority. Furthermore, it needs less number of messages transmitted. Finally, it is simple and easy to implement. [ABSTRACT FROM AUTHOR]

Recently, wireless sensor networks have employed the concept of mobile agent to reduce energy consumption and obtain effective data gathering. Typically, in data gathering based on mobile agent, it is an important and essential step to find out the optimal itinerary planning for the mobile agent. However, single-agent itinerary planning suffers from two primary disadvantages: task delay and large size of mobile agent as the scale of the network is expanded. Thus, using multi-agent itinerary planning overcomes the drawbacks of single-agent itinerary planning. Despite the advantages of multi-agent itinerary planning, finding the optimal number of distributed mobile agents, source nodes grouping, and optimal itinerary of each mobile agent for simultaneous data gathering are still regarded as critical issues in wireless sensor network. Therefore, in this article, the existing algorithms that have been identified in the literature to address the above issues are reviewed. The review shows that most of the algorithms used one parameter to find the optimal number of mobile agents in multi-agent itinerary planning without utilizing other parameters. More importantly, the review showed that theses algorithms did not take into account the security of the data gathered by the mobile agent. Accordingly, we indicated the limitations of each proposed algorithm and new directions are provided for future research. [ABSTRACT FROM AUTHOR]

Transmission power allocation in modern mobile telecommunication systems is one of the most important aspects affecting overall performance. Addressing this issue has huge impact on improving state-of-the-art for mobile telecommunication systems such as Long Term Evolution—Advanced by reducing inter-cell interference. To approach global optimality, some sort of cooperation between base stations is needed to overcome many shared limitations. This article proposes cooperative transmission power assignment mechanism based on the coordinated multiple points’ concept. It provides mathematical treatment and technical development for the proposed solution. This solution works in distributed fashion which is one of the main strengths of our approach. The proposed transmission power mechanism adopts auction theory approach to allocate power level for each base station. The proposed solution has showed tremendous good performance in extensive simulation experiments. [ABSTRACT FROM AUTHOR]

Broadcasting is an essential and effective mechanism used to disseminate data on several types of networks such as mobile ad hoc network. Such method is adopted by a considerable number of routing protocols, in particular, in the route discovery stage since the broadcasting is easy to implement and certainly provides an ideal connectivity among nodes. However, the broadcasting increases the routing overhead, packet delay, which negativity affects the throughput due to the excessive use of the redundant Route REQuest message. In addition, the network is susceptible to so-called broadcast storm problem. Therefore, developing a new routing protocol, which is able to relieve the unnecessary Route REQuest messages while boosting the performance of the network, is required. In this article, a novel routing protocol for mobile ad hoc network, called scalable neighbor-based mobile routing, is proposed. The broadcasting in this protocol is governed by the inverse relation between the number of neighbors and the probability of the rebroadcasted Route REQuest messages. Extensive simulation experiments are carried out to evaluate the performance of the proposed protocol and to compare the state-of-the-art protocols, namely, neighbor coverage-based probabilistic rebroadcast, with the latest version of ad hoc on-demand distance vector protocol. Simulation results show that scalable neighbor-based mobile routing outperforms both protocols, the neighbor coverage-based probabilistic rebroadcast and the ad hoc on-demand distance vector, in terms of routing overhead, medium access control collision, end-to-end delay, packet delivery ratio, and energy consumption. [ABSTRACT FROM AUTHOR]

Nonuniform node deployment makes the cluster-based routing protocol less efficient in wireless sensor networks (WSNs). Energy aware distributed clustering (EADC) is one of the cluster-based routing protocols proposed for networks with nonuniform node distribution, which can effectively balance the energy consumption among the nodes. However, due to the nonuniform node distribution, there is a redundancy in sensed and transmitted data in dense area. This unnecessary energy consumption is not considered in EADC. Therefore, in this paper, a new algorithm called scheduled activity EADC (SA-EADC) is proposed. SA-EADC exploits the redundant nodes and turns them off for the current round. The redundant nodes are scheduled based on their residual energy to work alternatively. The results show that SA-EADC significantly decreases the energy consumption and extends the network lifetime without degradation in coverage and sensing reliability of the network. [ABSTRACT FROM AUTHOR]