With the rapidly development of natural gas production, storage and transportation, the requirement for safety monitoring on natural gas industry are continuously increasing. This paper analyzes the application of WSN (wireless sensor network) in natural gas industry safety monitoring, and proposes a layered structure for large scale WSN based safety monitoring system, which can be used in collecting various kinds of safety information in natural gas industry, and sending them to surveillance center for data analyzing and early warning of abnormal situation. In the structure, we discuss the deployment of sensor nodes, sink nodes and e-sink nodes, and proposed the layered data fusion model and query model.

Abstract:In the HDFS cloud storage environment, the existing replica strategy is not able to adopt the optimal replica according to the current system environment dynamically, which affects the performance of the Cloud Storage system. This paper aims at the replica selection strategies in the load balancing problem, proposes a Replica Strategy based on grey prediction theory in Cloud Storage and predicts the node load rate of different replicas at a moment, selecting the minimum load node dynamically, eventually to load balance.

Machine-to-machine (M2M) communications can be widely used in military probing, disasters monitoring, etc., where have rigorous environment and require reliable communications. In order to provide enough reliability, M2M subnet can be deployed with two inter-backup aggregation points. This paper proposed a novel routing algorithm named Fermat Point based Joint Routing (FPJR) for such dual-aggregation-points inter-backup M2M Communications. Taking nodes on Fermat Points as route anchors, FPJR forms joint routes which can decrease energy cost and improve communication efficiency greatly. Further, considering the probability is quite little that there is exactly a node deployed on an appointed Fermat Point, we proposed a new terminology ‘ -Fermat Region’, which denotes the circle area with the Fermat Point as center and as radius. Based on -Fermat Region and through the FPJR interaction protocol, FPJR can act not only separately but also as the aid of other routing algorithms, without any compatibility problem. The simulation results show that FPJR can greatly decrease packet lost ratio, energy cost and packet delay.

Integration of the wireless LANs (WLAN) and 3G networks, such as Universal Mobile Telecommunication Service (UMTS), has been intensively studied recently due to their complementary characteristics. In this paper, we design and implement a flexible protocol stack architecture which can support concurrent transmission via multiple radio interfaces. Furthermore, the multiple services with various QoS requirements are differentiated and transported in the best wireless access network which is determined by the proposed network selection criterion-- Multi-Criteria Decision Making (MCDM), in the heterogeneous wireless network. Simulation results demonstrate that the proposed concurrent transmission scheme improves the network utility and provide the QoS services among the multiple wireless access networks more efficiently.