Wireless Multimedia Sensor Network Node Research Articles

Design and implementation of wireless multimedia sensor network node based on FPGA and binocular vision

According to the actual demand of the wireless sensor network for multimedia information acquisition, the new multimedia wireless sensor node is designed and implemented with FPGA as the core and Zigbee wireless communication. On the multimedia nodes, sensors such as binocular camera and accelerometer are configured to realize real-time perception and acquisition of environmental information and image data, and the short distance wireless communication and detection ability is formed through Zigbee protocol. When the test distance is not more than 60 m, the measured data fluctuate around the theoretical curve, and the communication is reliable. When the distance of the node is within the 14 m, the data transmission has no error. In view of the fact that the mismatch rate of the traditional Census transform is high under the condition of accuracy and noise, an improved Census transform stereo matching algorithm is proposed, which is applied to the nodes of multimedia sensor network. The experimental results show that this scheme can realize the data transmission and processing of wireless sensor network nodes and has strong operation capability and visual matching precision while reducing power consumption.

Energy and Delay Optimization of Heterogeneous Multicore Wireless Multimedia Sensor Nodes by Adaptive Genetic-Simulated Annealing Algorithm

Energy efficiency and delay optimization are significant for the proliferation of wireless multimedia sensor network (WMSN). In this article, an energy-efficient, delay-efficient, hardware and software cooptimization platform is researched to minimize the energy cost while guaranteeing the deadline of the real-time WMSN tasks. First, a multicore reconfigurable WMSN hardware platform is designed and implemented. This platform uses both the heterogeneous multicore architecture and the dynamic voltage and frequency scaling (DVFS) technique. By this means, the nodes can adjust the hardware characteristics dynamically in terms of the software run-time contexts. Consequently, the software can be executed more efficiently with less energy cost and shorter execution time. Then, based on this hardware platform, an energy and delay multiobjective optimization algorithm and a DVFS adaption algorithm are investigated. These algorithms aim to search out the global energy optimization solution within the acceptable calculation time and strip the time redundancy in the task executing process. Thus, the energy efficiency of the WMSN node can be improved significantly even under strict constraint of the execution time. Simulation and real-world experiments proved that the proposed approaches can decrease the energy cost by more than 29% compared to the traditional single-core WMSN node. Moreover, the node can react quickly to the time-sensitive events.

Dynamic Deployment of Wireless Multimedia Sensor Network Nodes Based on Balanced Energy Consumption

The quality of data sensing, storage, and interaction depends on node deployment, so the optimization of node deployment becomes the key mission to response network congestion. This paper studies the indoor sensor network nodes deployment and simulates the corresponding sensor network environment, in order to solve the congestion of wireless multimedia sensor network based on balanced energy. We introduce the balanced energy consumption of hybrid nodes deployment strategy to maximize use of network resources. The two-dimensional plane nodes are redeployed and further extended to three-dimensional space on the basis of energy equilibrium. The whole experiment states clearly that intelligent node deployment strategy use wireless multimedia sensor network node resources to effectively extend the network life cycle.

An Optimized Hidden Node Detection Paradigm for Improving the Coverage and Network Efficiency in Wireless Multimedia Sensor Networks.

Successful transmission of online multimedia streams in wireless multimedia sensor networks (WMSNs) is a big challenge due to their limited bandwidth and power resources. The existing WSN protocols are not completely appropriate for multimedia communication. The effectiveness of WMSNs varies, and it depends on the correct location of its sensor nodes in the field. Thus, maximizing the multimedia coverage is the most important issue in the delivery of multimedia contents. The nodes in WMSNs are either static or mobile. Thus, the node connections change continuously due to the mobility in wireless multimedia communication that causes an additional energy consumption, and synchronization loss between neighboring nodes. In this paper, we introduce an Optimized Hidden Node Detection (OHND) paradigm. The OHND consists of three phases: hidden node detection, message exchange, and location detection. These three phases aim to maximize the multimedia node coverage, and improve energy efficiency, hidden node detection capacity, and packet delivery ratio. OHND helps multimedia sensor nodes to compute the directional coverage. Furthermore, an OHND is used to maintain a continuous node– continuous neighbor discovery process in order to handle the mobility of the nodes. We implement our proposed algorithms by using a network simulator (NS2). The simulation results demonstrate that nodes are capable of maintaining direct coverage and detecting hidden nodes in order to maximize coverage and multimedia node mobility. To evaluate the performance of our proposed algorithms, we compared our results with other known approaches.

A Cross-layer and Multipath based Video Transmission Scheme for Wireless Multimedia Sensor Networks

The issue of video transmission for wireless multimedia sensor networks (WMSNs) was studied in this paper. Video applications were generally characterized by large data size and strong real-time requirement. However, nodes in WMSNs had limited resources and the quality of service for video applications was hard to ensure. This paper studied this problem and presented a cross-layer and multipath based video transmission scheme (CMVT). CMVT introduced the idea of differentiated service and multipath routing, and operated in both application layer and network layer. In application layer, different types of video frames were marked with different tags. Then in network layer these frames were identified by the tags and CMVT would forward them in different paths. Simulation results showed that, CMVT reduced the channel conflicts efficiently and balanced the power consumption of the network, which extended the network lifetime greatly. Also, it provided better video transmission quality.

Research on secure data collection in wireless multimedia sensor networks

Anti-attack during data collection is a crucial challenge in wireless multimedia sensor networks (WMSNs). Because WMSNs are usually deployed at unattended or hostile environments, an adversary can easily compromises several sensor nodes and controls them to launch attacks. These compromised nodes are difficult to be detected by traditional secure scheme due to having all keying materials. This paper proposes a novel trust evaluation model to detect the compromised nodes in WMSNs. Under our design, each node computes the trust value of their behaviors and builds a local trust management. Moreover, an energy-efficient secure routing is proposed to achieve secure data collection and meet the requirement of energy efficiency. The effectiveness of the proposed schemes is evaluated by analysis and extensive simulations.

Detecting External Disturbances on the Camera Lens in Wireless Multimedia Sensor Networks

Assessing the quality of images acquired by nodes of a wireless multimedia sensor network (WMSN) is a critical issue, particularly in outdoor applications where external disturbances such as the presence of water, dust, snow, or tampering on the camera lens may seriously corrupt the acquired images. In this paper, we address the problem of determining when the lens of a microcamera mounted on a WMSN node is affected by an external disturbance that produces blurred or obfuscated images. We show that such a problem can be solved by considering change detection tests applied to a measure of the blur intensity. Interestingly, both measuring the blur and the change detection test do not require any assumption about the content of the observed scene, its nature, or the characteristics of the blur. The proposed methodology is thus flexible and effective for a large class of monitoring applications. In particular, it is attractive when nodes cannot continuously acquire images (e.g., because of energy limitations) and background subtraction methods are not feasible. Two solutions, with different hardware costs, have been designed, which can detect disturbances on the camera lens at either/both the node or/and the remote station level.