Applied Mechanics and Materials Vols. 336-338

Abstract: In order to meet the requirements of Smart Grid in data acquisition, transmission reliability, stability, robustness and low power consumption of devices, ZigBee with its significant advantages of low power, low cost, low rate and easy to use, can play an important role in Smart Grid. As one of the key technologies of ZigBee, routing technology plays an important role in the performance optimization of network. Thus, in this paper, we focus on cluster-tree routing algorithm and hybrid routing algorithm in ZigBee network. Simulation and results show that, hybrid routing algorithm has better performance than cluster-tree routing algorithm in network throughput, average traffic received, average number of hops, network delay and network load.

Abstract: IEEE 802.1x is a port-based network access control protocol, the one of the newest authentication protocols. With the MD5 algorithm as an example, this paper introduces the type of protocol packets and the authentication process in detail. The authentication port is apart from the business stream based on the logical port. The business stream is transmitted over the controlled port, but the authentication stream is transmitted over the uncontrolled port. Therefore, the port control and authorization for users can be carried out. In this paper, two authentication methods based on EPON system are studied in detail. The 802.1x authentication protocol has many advantages, such as low-cost, simply and so on. It can satisfy the requirement of intelligent distribution network communication system.

Abstract: In view of the special nature of the marine network security, this paper is mainly based on the fuzzy set theory and entropy weight to some aspects of the network security risk assessment, and gives the description of scale, constructs the membership degree matrix of the corresponding evaluation factors, entropy weight coefficient method is used to determine the factor weights to reduce the traditional weight method for subjective deviation, Using system synthesis method, the safety risk value of each element of integration and then decides the grade of Marine network system security risk. The example analysis shows that the method is feasible and effective.

Abstract: In order to improve the security of home, an intelligent home security alarm system based on Micro-programmed Control Unit (MCU) has been designed in this paper, which can monitor the doors and windows, and communicate with intrusion alarm system by using GSM. Practical measured results indicate that this system can complete the function of home security alarm, which has a strong practical popularize value.In order to improve the security of home, an intelligent home security system based on MCU has been designed in this paper, which realizes en-mg checking, password storage, sound/short message warning service and real-time monitoring through GSM network. The hardware and software designs are illustrated in the paper. Finally, the test is carried out and the results indicate that the functions of system have achieved the design goal.

Abstract: The performance of ZigBee under interferences especially heavy WiFi hotpots has been more and more noticed in wireless sensor networks. Empirical results show that WiFi traffic contains abundant white space. It provides potential opportunities for ZigBee and WiFi to coexist in the same or overlapping channels. In this paper, we used the Pareto model to characterize the white space between WiFi frame clusters. Base on this model and a new ZigBee frame control protocol we developed, we gave out the best threshold of the model to achieve desired trade-offs between ZigBee link throughput and delivery ratio. According to experiments on the ZigBee Development Kits, the most suitable threshold of the Pareto model is 1.5ms. It could make a 10.9% throughput and 39.5% delivery ratio improvement.

Abstract: In this paper, we propose a novel green mechanism called Energy-Efficient Ring (EER) for multi-segment Fiber-Wireless (FiWi) access networks. We first utilize clustering scheme to generate clusters each with the shortest distance of fully connected segments in it. Leveraging backtracking method, we then connect segments in each cluster through fiber links and the shortest fiber ring is constructed in each cluster. Finally, we sleep low load segments and forward affected traffic to other active segments on the same fiber ring. Experimental results show that EER significantly reduces the energy consumptions at the slightly additional cost of deploying fiber links.

Abstract: Signaling storm becomes one of the complicated problems for 3G networks due to booming development of smart phones and mobile internet services. In this paper, the basic mechanisms of fast dormancy, resource allocation and periodic heartbeat signaling for typical services are analyzed, as signaling storm is caused by the discoordination between terminals, networks and services. Some improvement suggestions are also proposed to reduce the network overhead under the guaranteed user experience.

Abstract: After research on RIPv1 and RIPv2 of Dynamic Routing Protocol, simulation and modeling for RIPv1 and RIPv2 based on Packet Tracer simulation software. In the same simulation network topology, the simulation experiments compare RIPv1 and RIPv2 with the routing table, route update messages, route summarization, and the function of discontinuous network. The simulation results show that RIPv2 has more advantage than RIPv1.

Abstract: EIGRP is an enhanced version of IGRP, and is a private routing protocol of Cisco Systems, Inc. We analyze the packet format of EIGRP and the advantages including PDM, RTP, DUAL, rapid convergence times, low usage of network resources, and route summarization. In Packet Tracer simulation software, the simulation experiments configure EIGRP in a simple network topology. The simulation results show the different structure of EIGRP packet, and EIGRP supports well route summarization and provides extremely quick convergence times with minimal network traffic for low usage of network resources.

Abstract: DCell has been proposed for enormous data centers as a server centric interconnection which can support millions of servers with high network capacity and provide good fault tolerance by only using commodity switches. In this paper, we study an attractive algorithm of finding Hamilton paths in dimensional. The time complexity of this algorithm is , where is the node number of DCell_k .