Ruyan Wang

A hierarchical packet forwarding mechanism for energy harvesting wireless sensor networks

Energy harvesting technologies have gained widespread attention for their perpetual energy supply for sensor nodes. However, the energy resources are still insufficient while the harvesting module is added on the node. To prolong the network lifetime and meet the demand of a green wireless network, a dynamic gradient-aware hierarchical packet forwarding mechanism is designed. According to the relative positions of nodes, gradient-aware clusters are established. Consequently, considering the energy conversion efficiency and relative distance, cluster heads are selected reasonably. Furthermore, by exploiting the available energy and the number of cluster members, packets can be forwarded to the sink in an energy-efficient manner. Results show that the network lifetime can be noticeably improved.

Social Attribute Aware Incentive Mechanism for Device-to-Device Video Distribution

To offload and alleviate the heavy base station (BS) traffic load caused by the rapidly growing video services, device-to-device (D2D) communication, as one of the most indispensable technologies of the future cellular networks, can be potentially exploited by mobile users to distribute videos for a BS. In this paper, an effective pricing-based multicast video distribution system and a grid-based clustering method are proposed to support the distribution. Moreover, with the consideration of users’ mobility and social characteristics, we classify them into multicast and core types by studying the user stay probability and familiarity. In particular, core users can cooperate with the BS to distribute videos to the multicast users through intracluster D2D multicast. However, core users cannot selflessly help the BS to distribute videos; instead, they will evaluate their personal benefits before distributing the videos to the multicast users. Further, a Stackelberg game-based pricing mechanism is proposed to inspire the core users to distribute videos. Simulation results demonstrate that the proposed mechanism can not only effectively alleviate the BS traffic load, but also significantly improve the effectiveness and reliability of video transmission.

Dynamic Coding Control in Social Intermittent Connectivity Wireless Networks

In intermittent connectivity wireless networks, packets are always transmitted to their destinations through the cooperation of intermediate nodes, and the limited network resources can be effectively utilized through network coding approaches. However, a large amount of resources will be consumed while all the nodes act as coding nodes simultaneously; meanwhile, redundant coded packets are injected into the network. Therefore, to determine the number of coding nodes and restrain the diffusion of coded packets, a new dynamic coding control mechanism is proposed. In this mechanism, coding nodes are scheduled in a distributed manner based on the network community scale. Moreover, the coding opportunities and forwarding priorities of packets are determined according to the packet redundancy. Simulation results show that the connection opportunities can be exploited, and the utilization of network resources can be optimized.

Quality-of-protection-driven data forwarding for intermittently connected wireless networks

The data delivery in ICWN is accomplished in a collaborative manner, and non-cooperative behavior will gravely impair network QoP and user QoE. To select reliable relay nodes for data transmission, a trust-status-aware data forwarding strategy is proposed in this article. By exploiting locally recorded forwarding behavior information, process-based and relationship-based credibility can be precisely evaluated in a distributed manner. Additionally, with the assistance of an effective intrusion detection mechanism, reasonable relay selection can be perfected. Numerical results show that the proposed mechanism can provide reliable data transmission with high QoP and improved user QoE, which dramatically reduces the network load and enhances the resource utilization.

Node Service Ability Aware Packet Forwarding Mechanism in Intermittently Connected Wireless Networks

Intermittently connected wireless networks (ICWNs) have been studied in recent years to solve the disruption problem in mobile ad hoc networks and improve the utilization of temporary links raised by node movements. In ICWNs, the packet storing-carrying-forwarding principle is adopted through the cooperation between multiple nodes. Therefore, it is critical to include the connection status of nodes in designing efficient packet forwarding mechanism. In this paper, a node service ability aware packet forwarding mechanism is proposed based on the connection status. First, the connection model is established to analyze the transition of connection status; moreover, the service ability can be evaluated according to the connection strength and connection availability. Second, packet forwarding levels are determined based on their transmitting status to exploit the limited buffer resources. Consequently, the efficient packet forwarding mechanism can guarantee the flexibility of packet transmission in both complex and dynamic network scenarios. Numerical results show that about 20% delivery ratio increase can be achieved by the proposed mechanism, while the overheads and latency are reduced.

Socially Aware Energy-Efficient Mobile Edge Collaboration for Video Distribution

To relieve the current overload of cellular networks caused by the continuously growing multimedia service, mobile edge collaboration, which exploits edge users to distribute videos for base station (BS), provides an effective way to share the heavy BS load. With the emergence of mobile edge technologies for Internet-of-Things applications, such as device to device and machine to machine, how to exploit users’ social characteristics and mobility to minimize the number of transmissions of BS and how to improve the quality of experience of users have become the key challenges. In this paper, we study two aspects that are critical to these issues. One is the two-step detection mechanism, namely the establishment of virtual communities and collaborative clusters. Specifically, we take into consideration user preference for content and location. First of all, a virtual community is established, which exploits the coalition game based on the users preference list to dynamically divide users into multiple communities. Then, to take full advantage of the temporary link established between users, a grid-based clustering method is proposed to manage the video requesting users. On the other hand, we propose a scalable video coding sharing scheme based on users social attributes. This approach makes video distribution more flexible at the edge of mobile network through collaboration among users, and effectively reduces transmission energy consumption of transmitters. Numerical results show that the proposed mechanism can not only effectively alleviate the BS load, but also dramatically improve the reliability and adaptability of video distribution.

Social overlapping community-aware neighbor discovery for D2D communications

Because there are multiple social attributes of D2D devices, the accurate perception of these attributes can significantly enhance the neighbor discovery capability of D2D devices in cellular systems and further improve the efficiency of D2D communications. In this article, an accurate detection method of overlapping communities for D2D communications is proposed. By dynamically estimating the roles of overlapping community users in various communities, the corresponding beacon detection rates can be identified. Furthermore, the beacon detection rates can be dynamically adjusted according to the connection status of other intra-community and inter-community users to improve the system energy efficiency and neighbor discovery rates. Simulation results show that the proposed social overlapping community-aware (SOCA) neighbor discovery method for D2D communications can effectively improve system performance including both the neighbor discovery rate and data delivery ratio.

An Energy-Efficient Data Forwarding Strategy for Heterogeneous WBANs

Monitoring human bodies and collecting physiological information are the major healthcare applications for wireless body area networks (WBANs). Due to the limited energy resource of body sensors, their energy depletions will cause severe network performance degradation, such as latency and energy efficiency. The heterogeneity of body sensors can result in different sensor energy consumption rates. Besides, the important degrees of monitored physiological data could vary hugely. Targeting at the above-mentioned problems, an energy-efficient data forwarding strategy (EDFS) is proposed in this paper to balance sensor energy consumption and improve network lifetime and collaborative operations of heterogeneous WBANs. Our major contributions include: 1) the original physiological data are processed by compressed sensing to reduce the data size to be transmitted and 2) the remaining energy levels, sampling frequency, and sensor importance are jointly considered by EDFS for the optimal relay sensor selection. With the EDFS, the energy-efficiency and reliability of WBAN data transmission can be improved. In addition, our simulation results demonstrate that the proposed EDFS can effectively deal with the frequently changing WBAN topologies while providing balanced energy consumption and energy efficiency.

Security-oriented opportunistic data forwarding in Mobile Social Networks

Abstract In recent years, Mobile Social Networks (MSNs) have been arising a growing interest in both scientific and industrial fields for its potential value. The effective data transmission of MSNs is generally achieved through opportunistic forwarding and node collaboration. However, malicious nodes may illegally intercept and drop the data packets which should be forwarded. Therefore, it is very challenging to detect these malicious nodes. In this paper, we proposed a new Resisting On–Off Attack Data Forwarding Mechanism (OADM) for MSNs to detect the on–off attack, which not only prevents malicious nodes from intercepting data packets, but also exploits the node collaboration to forward data packets. Our major contribution includes: (1) Exploiting Hidden Markov Model (HMM) model to learn node behaviors for the evaluation of attacking probabilities and node states; (2) Effective relay node selection based the estimation of node capability. Results show the proposed OADM can effectively identify the attacking behavior and collaborating states of nodes and significantly improve the data delivery rate of MSNs.

Privacy-Preserving Multimedia Big Data Aggregation in Large-Scale Wireless Sensor Networks

To preserve the privacy of multimedia big data and achieve the efficient data aggregation in wireless multimedia sensor networks (WMSNs), a distributed compressed sensing--based privacy-preserving data aggregation (DCSPDA) approach is proposed in this article. First, in this approach, the original multimedia sensor data are compressed and measured by distributed compressed sensing (DCS) and the compressed data measurements are uploaded to the sink, by which the inherent characteristics between sensor data can be obtained. Second, the original multimedia data are jointly recovered and the common and innovation sparse components are obtained through solving the optimization problem and linear equations at the sink. Third, through least squares support vector machine (LSSVM) learning of the sparse components, the sparse position configuration can be determined and disseminated for each node to conduct the privacy-preserving data configuration. After receiving the configuration message, original multimedia sensor data are accordingly customized, compressed, and measured by the common measurement matrix, aggregated at the cluster heads, and transmitted to the sink. Finally, the aggregated multimedia sensor data are recovered by the sink according to the data configuration to achieve the privacy-preserving data aggregation and transmission. Our comparative simulation results validate the efficiency and scalability of DCSPDA and demonstrate that the proposed approach can effectively reduce the communication overheads and provide reliable privacy-preserving with low computational complexity for WMSNs.