Yuhua Liu

A Cluster Maintenance Algorithm Based on LEACH-DCHS Protoclol

LEACH-DCHS CM (LEACH-DCHS cluster maintenance) algorithm based on LEACH-DCHS algorithm is proposed in this paper. By prolonging the steady-state phase time and retaining the concept of round in the original algorithm, the new algorithm achieves the purpose of saving energy ultimately. Simulation results validate the energy efficiency of LEACH-DCHS CM algorithm.

The incentive secure mechanism based on quality of service in P2P network

In order to overcome the disadvantages of appearing the free-rider phenomenon and security issues due to the characteristics of anonymity and voluntary contributions resources in P2P network, this article firstly proposes a new strategy that based on trust value and considers both the quality and the number of shared resources to avoid the phenomenon of free rider. In the new strategy, we can calculate the trust value of the files in accordance with the consumer nodes trust values, obtain nodes effective contribution values, and select the node that has bigger trust value as service provider node. Moreover, the network can be divided into several regions according to the physical distances between nodes in the network. The nodes locating nearer are allocated the same region that is called cluster. In every cluster, we can select several nodes that have good physical properties and stability as management node to store and process all the information in the cluster and communicate with other management nodes in other clusters. In order to reduce overhead of network communication, encourage the nodes to make more transactions in the same cluster. Simulations prove that this strategy can guarantee the quality of service as well as restrain free-rider phenomenon, so as to enhance the utilization of resources and the success rate of transaction.

Fair incentive mechanism with pyramidal structure for peer-to-peer networks

Free-riding is a grave threat against the existence and efficient operation of peer-to-peer networks. This study proposes a rank-based fair incentive mechanism to restrain free-riding and solve the problem of the tragedy of the commons. In this mechanism, each user has a rank according to its utility value and it can just visit the corresponding rating files with its rank in the system. The utility function in this study takes the absolute contribution value and the physical performance into account for fairness and their values are calculated by the analytic hierarchy process. Besides, a pyramidal rank structure is constructed in this mechanism, and the computation formula for the nodes transfer in each layer is established. In addition, the four defects in other restrain mechanisms are resolved in this incentive mechanism. The simulations in three aspects have verified that this mechanism is effective and practical.

Distributed Routing for Wireless Sensor Networks Based on Cluster Maintenance

Saving energy is an important goal in designing of wireless sensor networks, and routing algorithm has an important impact on energy consumption for wireless sensor networks. Therefore, improving the energy efficiency of routing algorithm to reduce energy consumption in the network is very necessary. This paper proposes a new distributed routing algorithm based on cluster maintenance (CMDR-LD). By prolonging the steady-state phase time and retaining the concept of round in routing algorithm, the new algorithm achieves the purpose of saving energy ultimately. Simulation results validate the energy efficiency of that algorithm.

An effective simulation method for search strategy in unstructured P2P network

Abstract Modeling and Simulation Techniques focus on simulation modeling and analysis challenges to develop principles or gain in existing networking technologies, including simulation methodology or application in unstructured P2P network. In this paper, we focus on the simulation in the random unstructured P2P network. The correlation between topology and search algorithm is less paid attention to in unstructured P2P network, current techniques used in existing unstructured P2P system are often very inefficient because of the existence of large number of redundant messages. In this paper, we analyze the reason of engendering redundant data packet and focus on designing better search algorithm to adapt to the current network rather than to design the universal algorithm to adapt to a variety of network. Analyzing the characteristics that the flooding algorithm showing in different search stages in different network, we put forward the segment search algorithm. Furthermore, we present an effective simulation method in the random unstructured P2P network. Through simulation analysis, we find that our algorithm is better than the original flooding algorithm. In addition, we design our algorithm to be simple as a module, which can be easily applied to existing unstructured P2P systems for immediate impact.

A Segment Strategy Based on Flooding Search in Unstructured P2P Network

The correlation between topology and search algorithm is less paid attention to in unstructured P2P network. In this paper, we focus on designing better search algorithm to adapt to the current network rather than to design the universal algorithm to adapt to a variety of network. Analyzing the characteristics that the flooding algorithm showing in different search stages in different network, we put forward the segment search algorithm. Through experiments we find that it has good results. In addition, we design our algorithm to be simple, as a module that can be easily applied to existing unstructured P2P systems for immediate impact.

A Research about Redundant Data Packet in Unstructured P2P Network

Peer-to-Peer systems depend on effective techniques to find and retrieve data; however, current techniques used in existing unstructured P2P system are often very inefficient because of the existence of large number of redundant messages. In this paper, we analyze the reason of engendering redundant data packet and put forward the Condensing Forward-List algorithm to reduce redundancy. Through experiments we find that it has good results. In addition, we design our algorithm to be simple, as a module that can be easily incorporated into existing unstructured P2P systems for immediate impact.

A secure model for controlling the hubs in P2P wireless network based on trust value

Recently a lot of efforts are focused on the most promising solutions in future communication environments with information and communication security technologies. As a result of anonymity and contribution resources voluntary of nodes in P2P wireless network, the overwhelming nodes lack enthusiasm when they provide service, which is easy to cause free riding phenomenon. Thus, it leads to the emergence of hubs. Due to the existence of hubs in P2P wireless networks, the network becomes much more vulnerable because of great reducing in defending against coordinated attacks. Therefore, in this paper we provide a secure model for controlling the hubs in P2P network based on trust value. In detail, this paper proposes a model based on trust value of nodes against vulnerability, which not only takes into account a nodes connections, but also gives full consideration about a nodes trust value. The calculation of trust value is broken down to various types of resources. In accordance with the type of pre-transaction resources, the nodes that have higher trust value and fewer connections are chosen to make transaction. Simulation results demonstrate that this model can encourage nodes to participate in sharing recourses with other nodes in the network actively, and simultaneously it can avoid generating hubs effectively. Our model could improve the ability of defending against coordinated attacks, and also could enhance the network robustness and stability.

The research based on trust value against vulnerability in P2P networks

Due to the existence of hubs in P2P networks, the network becomes more and more vulnerable because of great reducing in defending against coordinated attacks. This paper propose a model based on trust value of nodes against vulnerability, which not only takes into account the nodes connections, but also gives full consideration about the nodes trust value, and the calculation of trust value is broken down to various types of the resources. In accordance with the type of pre-transaction resources, selects nodes that have higher trust and fewer connections to make transaction. Simulation proves that this model can avoid generating hubs effectively, improve the ability to defend against coordinated attacks, and also enhance the network robustness and stability.

A Clustering Algorithm Based on Communication Facility with Deterministic Cluster-Size in WSN

With the energy constrained nature of wireless sensors, it is a substantial design issue to make efficient use of battery power in order to increase their lifetime. Focuses on reducing energy consumption of wireless sensor network, this paper proposed CABCF-DCS (clustering algorithm based on communication facility with deterministic cluster-size) algorithm. By changing the cluster-size of the cluster based on CABCF (clustering algorithm based on communication facility) algorithm, the new algorithm achieves the purpose of saving energy ultimately. Simulation results validate the energy efficiency of the new algorithm.