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Yan H.,Beijing University of Technology | Zhang Y.,China Mobile Communications Group | Pang Z.,ABB | Xu L.D.,CAS Institute of Computing Technology | And 3 more authors.
IEEE Transactions on Industrial Informatics | Year: 2014

Industrial wireless sensor network (IWSN) is a key enabling technology for the Internet-of-things (IoT). IWSN acts as one of the fundamental elements of the IoT infrastructure to bridge the physical sensors and actuators in field and backbone systems in the Internet. For deterministic performances, all mainstream IWSN standards utilize the slotted media access control (MAC) where the communication is allocated based on the superframe that comprises a number of slots in either contention-based access or contention-free access modes. In this paper, the planning of the superframe structure of the slotted MAC is investigated by two means: 1) a mathematical model of the MAC access latency based on the queue theory; and 2) an easy-to-use software tool based on packet-level simulation. The mathematical model gives an overall estimation of the average MAC access latency of the whole network. The software tool gives the exact latency of each packet and then can derive the optimal superframe structure of the network. The two means are validated correspondingly. With the methods proposed in this paper, IWSN designers can minimize the MAC access latency while satisfying the requirements at different generating rates of packet, number of nodes in the network, and packet buffer length of each node. © 2012 IEEE. Source


Xiao D.,Beijing University of Posts and Telecommunications | Su L.-Y.,China Mobile Communications Group | Wang J.-L.,Public Technology Service | Zheng S.-H.,Beijing University of Posts and Telecommunications | Yang Y.,Beijing University of Posts and Telecommunications
Beijing Youdian Daxue Xuebao/Journal of Beijing University of Posts and Telecommunications | Year: 2015

The development of cloud storage service is one of the key elements to cloud data technology. New data storage architecture for cloud storage service based file systems was proposed. And the design and implementation of cloud storage-backed file system based on the architecture (CSFS) was described. The development and deployment costs are reduced by utilizing free email service. The efficiency and scalability are increased by separated management of metadata, data block, distributed storage and cloud data prefetching. Experiments show that the optimization method improves the read and write performance of the system effectively. ©, 2015, Beijing University of Posts and Telecommunications. All right reserved. Source


Zhu H.-J.,Qiqihar University | Li D.F.,China Mobile Communications Group
Advanced Materials Research | Year: 2014

The group customer line service has become one of the key businesses for communication operators, and the line PTN technology development currency, the PTN technology application, and the development trend are researched. According to the PTN technology and client group line error correction algorithm, the multi granularity hash correction algorithm is used for data video aware, and when the PTN data is changed fast, the fuzzy block effect happened. The customer line service performance is bad. An improved group customer line correction algorithm is proposed based on PTN technology. The hidden Markov model is used for packet loss rate prediction, and the multiple steps are selected in random, and the data stream iteration algorithm is designed. The tamper detection algorithm is obtained. PTN technology group customer line correction is realized. Simulation results show that the new method can reduce error transmission rate of the PTN group customer line, the customer loss and delay of the data transmission can be controlled, and the peak signal to noise ratio is improved, the error correction performance is better, and it can be effectively applied to communications operator service. © (2014) Trans Tech Publications, Switzerland. Source


Qiang G.,Nanjing Southeast University | Lei C.,China Mobile Communications Group
Conference Proceedings of the International Symposium on Signals, Systems and Electronics | Year: 2010

Due to the dynamic characteristics of the available spectrum for secondary users inherent in cognitive radio network, to avoid interference among secondary users, available radio resources should be allocated coordinately among them, thus control channel is needed. In multi-hop cognitive radio networks, a control channel common to all secondary users is not available, and control channel has to be selected in a distributed fashion. The control channel selection problem in multi-hop cognitive radio network is investigated in this paper. A distributed algorithm is proposed with the goal to minimize the number of control channel in the whole network. The control channel selection scheme for each node is obtained. Simulation results show that with the increase of total available channels, the required number of control channel decreases. © 2010 IEEE. Source


An Q.,Huawei | Gao J.,China Mobile Communications Group
INTELEC, International Telecommunications Energy Conference (Proceedings) | Year: 2014

In the field such as telecommunications, UPS, finance, electric power and so on, the VRLA batteries are usually used in a series connection, but when there exists a faulty or several faulty batteries, the performance/life of the battery bank will deteriorate seriously to endanger the safety of power supply. After inspecting and analyzing the problem occurred of the battery backup time shortage in the actual site, we found that almost all the problems are due to the faulty battery existance in spite of the other batteries being still healthy. In this paper the author has studied some indicators commonly used to describe the uniformity of the VRLA battery, but found that these indicators only concern the initial state of the battery when they start to use rather than the internal factors to affect the uniformity of the VRLA battery really. When the battery is put into operation, due to the complexity and the diversity of the environment battery working, the same initial state of the VRLA battery cannot make sure the same performance/life throughout the lifespan. We can use the fishbone diagram method, which is a comprehensive analysis of various factors affecting the uniformity of the VRLA battery, from six aspects, 5M1E, namely Man, Machine, Material, Method, Measurement and Environment, to find out the key influencing factors and improve them. Furthermore, by means of the wireless distributed online real-time monitoring technology, we can monitor, even remote monitor the state of the VRLA battery, detect the faulty battery accurately, then replace it promptly to ensure the safety of power supply for the network. © 2014 IEEE. Source

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