Applied Mechanics and Materials Vols. 536-537

Abstract: With the number of the city vehicle increasing, traffic congestion has become a big problem. Thus the demand for vehicle accurate monitoring and scheduling is increasingly urgent. A wireless communication module based on GPS/GPRS has been designed in this paper, which is used to transmit the vehicle position information and other related data to the server wirelessly by GPRS. The STM8S207 microcontroller produced by the STMicroelectronics is used as the controller which is adopted as the communication module. The NEO-6M module and the wireless module MG323 with embedded TCP/UDP protocol are combined to acquire and monitor the vehicle data. The communication module designed in this paper can ensure the accuracy of GPS data and the real-time of GPRS transmission.

Abstract: Unlike other networks based on wireless sensor networks, such as the characteristics of Ad hoc network design algorithm to reduce the energy consumption of wireless sensor networks. The main study of wireless sensor networks in a variety of energy-saving protocols and algorithms, analyze the impact of these agreements on energy saving in different environments, MAC protocol for wireless sensor network design energy efficient use of its improvement, based on the maximum advantage disjoint approximate area set covering algorithm. Energy efficient or superior energy savings in the paper can prolong survival time of the network to provide scientific reference.

Abstract: A high-performance space-time two dimensional RAKE receiving algorithm was proposed in asynchronous cooperative communication system. the transmitting signals were estimated coarsely by traditional space-time rake receiver, then on the basis of that we introduce feedback technology, each multipath signal of transmitted signals was composed by the decision results, and then every multipath component in the received signal can be obtained by eliminating the composed multipath signals from the received signal. Finally, the multipath components were combined by space-time combination and multipath combination rules accordingly, so spatial as well as multipath diversities were achieved. Simulation results show that the new scheme can reduce the bit error rate dramatically compare with traditional space-time RAKE in asynchronous cooperative communication system.

Abstract: The network coverage condition of China Mobile Multimedia Broadcasting (CMMB) affects the signal quality of the CMMB terminal directly. The requirements of signal coverage are different in different regions, the co-channel interference and the interference caused by signal in adjacent areas must be considered in the planning of transmitting station. In the process of transmitting station construction, reasonable planning for network coverage is helpful to save costs and improves the quality of the network. In this paper, the planning principle of CMMB coverage network was analyzed firstly, and then an effective solution for network planning was presented according to the specific needs and the condition of network construction in Fuzhou province. On the basis of controlling construction cost, the solution achieves the required network coverage ratio.

Abstract: Event-driven systems and thread-driven systems are two major design philosophies of operating system in wireless sensor networks. Systems based on multi-threaded are more timeliness than the event-driven systems, which can meet the requirements of time-critical tasks by means of task preemption, while systems based on event-driven are more energy efficient.The article introduces a task scheduling module in event-driven system. The module takes a kind of priority table query method to choose the most important task with highest priority to schedule.It is seen that the module is suitable wireless sensor network.

Abstract: The uneven distribution of node energy consumption leads network to premature failure under LEACH protocol for wireless sensor network. For such problem, this paper presents a comprehensive algorithm. The residual energy will be taken into account when the cluster head is selected, and then multi-hop is used for forwarding in the process of transferring data. This achieves balanced distribution of network energy effectively. Simulation results show that the improved algorithm can prolong network lifetime, which is significantly better than LEACH protocol.

Abstract: This paper presented a approach, called LBS, for modeling and implementing the architecture of wireless sensor networks (WSNs) publish/subscribe (Pub/Sub) applications using a local broker subcomponent (LBS) model. Considering the reconfigurability of WSNs applications which was necessary for WSNs middleware, a graph oriented local broker subcomponent (GOLBS) model was defined based on the LBS model by integrated WSNs middleware with Pub/Sub. The analysis indicated that GOLBS provided reconfiguration management and non-predefined dynamic reconfiguration management for WSNs middleware. The results imply that GOLBS can easily be constructed, while ensuring good reconfigurability.

Abstract: Energy consumption is an open issue in research field of Wireless Sensor Networks (WSNs). Low Energy Adaptive Clustering Hierarchy (LEACH) protocol is the most additional routing protocol in WSNs. In LEACH, Cluster Head (CH) is selected randomly, not considering any parameter such as node energy, distance, which causes shortening its lifetime while energy consumption is unbalanced in WSNs. In this paper, it proposes a new LEACH-based protocol, energy consumption balance LEACH protocol. Firstly, all nodes are grouped based on their locations, and a CH is elected in every group, which ensures CHs even distribution in the network area. And an important factor selecting CHs, node energy is considered, which further energy consumption in WSNs. The results of simulation show that ECB-LEACH can increase energy efficiency and prolong the network lifetime.

Abstract: Recently, the SUAV has become the research focus at home and abroad. There is a new aircraft type: double ducted tilting Subminiature UAV system, this paper put forward a new attitude navigation system:AHRS-based low-cost GPS carrier phase orientation Navigation System. AHRS aids GPS fastly fix the attitude.This article proposed application the constraint solving the ambiguity basic model, which is based on the double differential equations of the carrier phase measurement. Then we use baseline length and the inaccurate attitude angle constraint to solver integer ambiguity. By the static experimental results show that this method is fast, effective, the AHRS-GPS system can provide high accuracy navigation for SUAV.

Abstract: Information of topology is significant for network planning and management in the Wireless Sensor Network (WSN). In this paper we propose a topology identification algorithm based on data fusion system in WSN. Firstly, the algorithm got the collections of approximate ancestors of each node according to the information of packet delay and/or packet loss. Secondly, it identifies parent-child relationship of the nodes by calculating the Hamming distance between the current node and approximate ancestors nodes; and infers the topology of the network layer by layer. It use end-to-end measurements and does not incur any additional burden on the network. NS2 simulation results show the high accuracy and efficiency of the proposed algorithm.