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    FEATURE TOPIC: TELECOMMUNICATIONS FOR REMOTE MEDICINE
  • FEATURE TOPIC: TELECOMMUNICATIONS FOR REMOTE MEDICINE
    Healthcare Algorithms by Wearable Inertial Sensors: A Survey
    AO Buke, FANG Gaoli, WANG Yongcai, SONG Lei, YANG Zhiqi
    2015, 1(4): 1-12.
    Abstract ( )   Knowledge map   Save
    Wearable smart devices, such as smart watch, wristband are becoming increasingly popular recently. They generally integrate the MEMS-designed inertial sensors, including accelerometer, gyroscope and compass, which provide a convenient and inexpensive way to collect motion data of users. Such rich, continuous motion data provide great potential for remote healthcare and decease diagnosis. Information processing algorithms play the critical role in these approaches, which is to extract the motion signatures and to access different kinds of judgements. This paper reviews key algorithms in these areas. In particular, we focus on three kinds of applications: 1) gait analysis; 2) fall detection and 3) sleep monitoring. They are the most popular healthcare applications based on the inertial data. By categorizing and introducing the key algorithms, this paper tries to build a clear map of how the inertial data are processed; how the inertial signatures are defined, extracted, and utilized in different kinds of applications. This will provide a valuable guidance for users to understand the methodologies and to select proper algorithm for specific application purpose.
  • FEATURE TOPIC: TELECOMMUNICATIONS FOR REMOTE MEDICINE
    A Precise RFID Indoor Localization System with Sensor Network Assistance
    ZHANG Dian, LU Kezhong, MAO Rui
    2015, 1(4): 13-22.
    Abstract ( )   Knowledge map   Save
    Indoor localization is very critical for medical care applications, e.g., the patient localization or tracking inside the building of the hospital. Traditional Radio Frequency Identification (RFID) technologies are very popular in this area since their cost is very low. In such technologies, each tag acts as the transmitter and the Radio Signal Strength Indicator (RSSI) information is measured from the readers. However, RSSI information suffers severely from the multi-path phenomenon. As a result, if in a very large area, the localization accuracy will be affected seriously. In order to solve this problem, we introduce Wireless Sensor Networks (WSNs) with only a few nodes, each of which acts as both transmitter and receiver. In such networks, the change of signal strength (referred as dynamic of RSSI) is leveraged to select a cluster of reference tags as candidates. Then the final target location is estimated by using the RSSI relationships between the target tag and candidate reference tags. Thus, the localization accuracy and scalability are able to be improved. We proposed two algorithms, SA-LANDMARC, and COCKTAIL. Experiments show that the localization accuracy of the two algorithms can reach 0.7m and 0.45m, respectively. Compared to most traditional Radio Frequency (RF)-based approaches, the localization accuracy is improved at least 50%.
  • FEATURE TOPIC: TELECOMMUNICATIONS FOR REMOTE MEDICINE
    A Portable Fall Detection and Alerting System Based on k-NN Algorithm and Remote Medicine
    HE Jian, HU Chen
    2015, 1(4): 23-31.
    Abstract ( )   Knowledge map   Save
    This paper presents information on a portable fall detection and alerting system mainly consisting of a custom vest and a mobile smart phone. A wearable motion detection sensor integrated with tri-axial accelerometer, gyroscope and Bluetooth is built into a custom vest worn by elderly. The vest can capture the reluctant acceleration and angular velocity about the activities of daily living (ADLs) of elderly in real time. The data via Bluetooth is then sent to a mobile smart phone running a fall detection program based on k-NN algorithm. When a fall occurs the phone can alert a family member or health care center through a call or emergent text message using a built in Global Positioning System. The experimental results show that the system discriminates falls from ADLs with a sensitivity of 95%, and a specificity of 96.67%. This system can provide remote monitoring and timely help for the elderly.
  • FEATURE TOPIC: TELECOMMUNICATIONS FOR REMOTE MEDICINE
    Cognitive Emotion Model for Eldercare Robot in Smart Home
    HAN Jing, XIE Lun, LI Dan, HE Zhijie, WANG Zhiliang
    2015, 1(4): 32-41.
    Abstract ( )   Knowledge map   Save
    Based on the smart home and facial expression recognition, this paper presents a cognitive emotional model for eldercare robot. By combining with Gabor filter, Local Binary Pattern algorithm (LBP) and k-Nearest Neighbor algorithm (KNN) are facial emotional features extracted and recognized. Meanwhile, facial emotional features put influence on robot’s emotion state, which is described in AVS emotion space. Then the optimization of smart home environment on the cognitive emotional model is specially analyzed using simulated annealing algorithm (SA). Finally, transition probability from any emotional state to a state of basic emotions is obtained based on the cognitive reappraisal strategy and Euclidean distance. The simulation and experiment have tested and verified the effective in reducing negative emotional state.
    • REVIEW PAPERS
  • REVIEW PAPERS
    Internet Plus and Networks Convergence
    ZENG Jianqiu, YANG Mengke
    2015, 1(4): 42-49.
    Abstract ( )   Knowledge map   Save
    This paper discusses the relationship between Internet plus and networks convergence and highlights the development of ICT industry and the process of networks convergence. Based on Internet plus and the theory of networks convergence, this paper suggests to implement Internet plus action plan as a strategy to accelerate the construction of networks and application of Internet, promote the traditional industry reform with ICT, increase competitive efficiency, standardize the market competition, and then realize the Internet plus strategy and networks convergence.
  • REVIEW PAPERS
    ZTE’s Perspective on Applying OFDM-PON in Next Converged Optical and Wireless Networks
    ZHU Songlin, GUO Yong, YIN Yongjia
    2015, 1(4): 50-57.
    Abstract ( )   Knowledge map   Save
    Driven by ZTE and other telecom vendors and operators in order to meet the ever increasing bandwidth demand from fixed optical network users and mobile backhaul/fronthaul services, the latest next generation passive optical network (NG-PON2) is being standardized by Full Service Access Network (FSAN) and International Telecommunication Union (ITU-T) which consists of two separated sub-systems, hybrid time- and wavelength-division multiplexing PON (TWDM-PON) and point-to-point wavelength- division multiplex (PtP WDM). The TWDM-PON will be used for traditional residential, business and wireless backhaul services which are not sensitive to time delay and delay variation, whereas the PtP WDM is mainly used for emerging wireless fronthaul service which is very sensitive to the time delay and time delay variation. However, as a main international standards’ contributor, ZTE thinks for those operators who offer multiple-level of services to both residential, business and mobile backhaul/fronthaul users, this obviously raises significant economic and power concerns by demanding to deploy two separated systems. Therefore, in this paper, for the first time, ZTE proposes a new converged optical and wireless integrated network architecture and topology by applying orthogonal frequency division multiplexing (OFDM) PON technology, which is able to simultaneously support residential, business and mobile backhaul/fronthaul services in terms of meeting the requirements of both time delay sensitive and non-sensitive services, and also address the economic and power concerns compared with conventional technologies. This architecture is further investigated and analyzed in depth on functional block, Quality-of-service (QoS), synchronization and deployment considerations. Also ZTE reports in this paper the first 40Gbps OFDM-PON prototype in which eight wavelengths each with 5Gbps Ethernet data via 10G-PON encapsulation method (X-GEM) and 10G-PON transmission convergence (X-GTC) framing are demonstrated.
    • COMMUNICATIONS SYSTEM DESIGN
  • COMMUNICATIONS SYSTEM DESIGN
    Optimal Rate Allocation Based on Cross-Layer Design and End-to-End Congestion Control in WCDMA Networks
    LI Yuzhou, SHI Yan, SHENG Min, LIU Guoqing, XU Chao
    2015, 1(4): 58-75.
    Abstract ( )   Knowledge map   Save
    In this paper, a novel idea for rate allocation combining both vertical coupling and horizontal coupling constraints is proposed, and a unified utility function to balance two paradoxical issues: efficiency and fairness, revenue and cost is elaborated in WCDMA networks. Then, the optimal rate allocation problem is formulated as a network utility maximization (NUM) model based on cross-layer design and end-to-end congestion control, aiming at exploring the impacts of wired networks and the characteristics of radio access networks (RANs) on rate allocation. Furthermore, a distributed algorithm is derived, which can effectively match load states between RANs and wired networks, followed by a detailed illustration of the practical implementations. Numerical results demonstrate a significant performance improvement in the end-to-end throughput.
  • COMMUNICATIONS SYSTEM DESIGN
    High Sensitivity Acquisition Algorithm for DSSS Signal with Data Modulation
    SHEN Yuyao, WANG Yongqing, CHEN Jingyao, WU Siliang
    2015, 1(4): 76-85.
    Abstract ( )   Knowledge map   Save
    In direct sequence spread spectrum communication both for satellite-to-ground and inter-satellite links, the system constrains due to radio frequency spectral occupation, channel data throughput and link performances in terms of data channel coding which might result in a signal structure where the symbol duration is shorter than the pseudo code period. This can generate some difficulties in the DSSS signal acquisition due to the polarity inversion caused by the data modulation. To eliminate the influence due to polarity inversion, this paper proposes a novel acquisition algorithm based on the simultaneous search of the code phase, data phase and Doppler frequency. In the proposed algorithm the data phase is predicted and the correlation period for the coherent integration can be set equal to the symbol duration. Then non-coherent accumulation over different symbol is implemented in order to enhance the acquisition algorithm sensitivity; the interval of non-coherent accumulation is the least common multiple between the symbol duration and the pseudo code period. The algorithm proposed can largely minimize the SNR loss caused by data polarity inversion and enhance acquisition performance without a noticeable increase in hardware complexity. Theoretical analysis, simulation and measured results verify the validity of the algorithm.
  • COMMUNICATIONS SYSTEM DESIGN
    Correlation Combination Ambiguity Removing Technology for Acquisition of Sine-Phased BOC(kn,n) Signals
    LIU Wen, XI Yue, DENG Zhongliang, JIAO Jichao, YIN Lu
    2015, 1(4): 86-96.
    Abstract ( )   Knowledge map   Save
    Binary Offset Carrier (BOC) has been chosen as one of modulation methods in the future Global Navigation Satellite Systems (GNSS). Even though BOC signals can bring several advantages such as better track performance and higher positioning accuracy, there is a drawback that the autocorrelation functions have multiple side-peaks if BOC modulation is adopted. This characteristic will lead to false acquisition and the tracking loop will be locked in false phase point. The proposed Correlation Combination Ambiguity Removing Technology (CCART) cancelled all the side-peaks of the sine-phased BOC(kn,n) signals completely by making use of two kinds of correlation functions. Two kinds of sub-correlation functions were combined separately and then final correlation function without side-peaks was acquired. The simulation results are given and compared with other techniques. It is shown that acquisition will not be degraded with the increase of k.
    • NETWORK TECHNOLOGY AND APPLICATION
  • NETWORK TECHNOLOGY AND APPLICATION
    Superposition Effect of Passive Intermodulation for Cable Assemblies with Discrete Point-Sources
    ZHAO Pei, ZHANG Xupu, YANG Dacheng, HU Xiaoyan
    2015, 1(4): 97-105.
    Abstract ( )   Knowledge map   Save
    In order to expand the cell coverage of wireless cellular systems, the number of passive components in wireless systems has been substantially increased. There can be many passive intermodulation (PIM) point-sources even in a device or a radio link, which may add up constructively or destructively. A modified point-source model with lossy components is proposed to evaluate the superposition effect of the forward and reflected PIM in case of series connection. The index of the series connection factor (SCF) is employed for systems that incorporate multiple PIM sources to predict the important characteristics of the cumulative PIM, such as the maximum and minimum values and the limit form. Furthermore, some initial experimental results are given out and the deviation in the above-mentioned prediction is also analyzed.
  • NETWORK TECHNOLOGY AND APPLICATION
    An Optimized Vertical Handoff Algorithm Based on Markov Process in Vehicle Heterogeneous Network
    MA Bin, DENG Hong, XIE Xianzhong, LIAO Xiaofeng
    2015, 1(4): 106-116.
    Abstract ( )   Knowledge map   Save
    In order to solve the problem the existing vertical handoff algorithms of vehicle heterogeneous wireless network do not consider the diversification of network’s status, an optimized vertical handoff algorithm based on markov process is proposed and discussed in this paper. This algorithm takes into account that the status transformation of available network will affect the quality of service (QoS) of vehicle terminal’s communication service. Firstly, Markov process is used to predict the transformation of wireless network’s status after the decision via transition probability. Then the weights of evaluating parameters will be determined by fuzzy logic method. Finally, by comparing the total incomes of each wireless network, including handoff decision incomes, handoff execution incomes and communication service incomes after handoff, the optimal network to handoff will be selected. Simulation results show that: the algorithm proposed, compared to the existing algorithm, is able to receive a higher level of load balancing and effectively improves the average blocking rate, packet loss rate and ping-pang effect.
  • NETWORK TECHNOLOGY AND APPLICATION
    A Trust Management Scheme Based on Behavior Feedback for Opportunistic Networks
    CHEN Xi, SUN Liang, MA JianFeng, MA Zhuo
    2015, 1(4): 117-129.
    Abstract ( )   Knowledge map   Save
    In the harsh environment where node density is sparse, the slow-moving nodes cannot effectively utilize the encountering opportunities to realize the self-organized identity authentications, and do not have the chance to join the network routing. However, considering most of the communications in opportunistic networks are caused by forwarding operations, there is no need to establish the complete mutual authentications for each conversation. Accordingly, a novel trust management scheme is presented based on the information of behavior feedback, in order to complement the insufficiency of identity authentications. By utilizing the certificate chains based on social attributes, the mobile nodes build the local certificate graphs gradually to realize the web of “Identity Trust” relationship. Meanwhile, the successors generate Verified Feedback Packets for each positive behavior, and consequently the “Behavior Trust” relationship is formed for slow-moving nodes. Simulation result shows that, by implementing our trust scheme, the delivery probability and trust reconstruction ratio can be effectively improved when there are large numbers of compromised nodes, and it means that our trust management scheme can efficiently explore and filter the trust nodes for secure forwarding in opportunistic networks.
    • STRATEGIES AND SCHEMES
  • STRATEGIES AND SCHEMES
    Impact of Heterogeneity on Forwarding Schemes in Opportunistic Networks
    CHENG Gang, ZHANG Yong, SONG Mei, GUO Da, Amanda Matthews
    2015, 1(4): 130-139.
    Abstract ( )   Knowledge map   Save
    In the paper, we concentrate on the influence of heterogeneity on the performance of forwarding algorithms under opportunistic networks. Therefore, we first describe two different heterogeneous network models, and capture the heterogeneity which concern mobile nodes’ contact dynamics under the individual models and the spatial models. Then we investigate inter-contact time is not fully follow exponential distribution and compare the performance of the delivery delay between direct forwarding protocol and three-hop forwarding protocol under three network models. We illustrate the performance of message delivery delay under the spray and wait protocol and prophet protocol from simulation results. Our simulation results show that the heterogeneity should be considered for the performance of forwarding protocols.
  • STRATEGIES AND SCHEMES
    Timing Advanced Estimation Algorithm of Low Complexity Based on DFT Spectrum Analysis for Satellite System
    HE Yizhou, CUI Gaofeng, LI Pengxu, CHANG Ruijun, WANG Weidong
    2015, 1(4): 140-150.
    Abstract ( )   Knowledge map   Save
    In satellite mobile communication system, relative movement of the satellite and the terminal will cause a large Doppler offset. Timing advanced estimation with Zadoff-Chu sequence is sensitive to the frequency offset. When the frequency offset is larger than one times subcarrier spacing, the value of peak cannot be detected at the receiving end. To suppress the larger Doppler frequency shift, this paper proposes a novel timing advanced estimation scheme (TAE-MCD) for satellite communication system. In this algorithm, transmitted signal is divided into ZC sequence and its conjugate sequence. Using multiplication and DFT operation to find the estimated peak at the receiving end, and make subtraction with the obtained sequences at last. The scheme can not only inhibit the adverse effects of large Doppler frequency shift in timing estimation effectively, but also reduce the computational complexity at the receiving end and improve the work efficiency of the hardware. Simulations results show that TAE-MCD outperform the existing timing advanced estimation methods, on the condition of no additional time and frequency resource are needed.
  • STRATEGIES AND SCHEMES
    QoS Evaluation for Web Service Recommendation
    MA You, XIN Xin, WANG Shangguang, LI Jinglin, SUN Qibo, YANG Fangchun
    2015, 1(4): 151-160.
    Abstract ( )   Knowledge map   Save
    Web service recommendation is one of the most important fields of research in the area of service computing. The two core problems of Web service recommendation are the prediction of unknown QoS property values and the evaluation of overall QoS according to user preferences. Aiming to address these two problems and their current challenges, we propose two efficient approaches to solve these problems. First, unknown QoS property values were predicted by modeling the high-dimensional QoS data as tensors, by utilizing an important tensor operation, i.e., tensor composition, to predict these QoS values. Our method, which considers all QoS dimensions integrally and uniformly, allows us to predict multi-dimensional QoS values accurately and easily. Second, the overall QoS was evaluated by proposing an efficient user preference learning method, which learns user preferences based on users’ ratings history data, allowing us to obtain user preferences quantifiably and accurately. By solving these two core problems, it became possible to compute a realistic value for the overall QoS. The experimental results showed our proposed methods to be more efficient than existing methods.