A Real Plug-and-Play Fog: Implementation of Service Placement in Wireless Multimedia Networks

Initially as an extension of cloud computing, fog computing has been inspiring new ideas about moving computing tasks to the edge of networks. In fog, we often repeat the procedure of placing services because of the geographical distribution of mobile users. We may not expect a fixed demand and supply relationship between users and service providers since users always prefer nearby service with less time delay and transmission consumption. That is, a plug-and-play service mode is what we need in fog. In this paper, we put forward a dynamic placement strategy for fog service to guarantee the normal service provision and optimize the Quality of Service (QoS). The simulation results show that our strategy can achieve better performance under metrics including energy consumption and end-to-end latency. Moreover, we design a real Plug-and-Play Fog (PnPF) based on Raspberry Pi and OpenWrt to provide fog services for wireless multimedia networks.

A QoS-Based Multichannel MAC Protocol for Two-Tiered Wireless Multimedia Sensor Networks

Rapid penetration of small customized wireless devices and enormous growth of wireless communication technologies has already set the stage for large-scale deployment of wireless sensor networks. Offering precise quality of service (QoS) for multimedia transmission over sensor networks has not received significant attention. However offering some better QoS for wireless multimedia over sensor networks raises significant challenges. In this paper, we propose an adaptive Cross-Layer multi-channel QoS-MAC protocol to support energy-efficient, high throughput, and reliable data transmission in Wireless Multimedia Sensor Network (WMSNs). Our proposed protocol use benefit of TDMA and CSMA/CA to adaptively assign channels and timeslots to active multimedia sensor nodes in clusters. Simulations show that the proposed system achieves the performance objectives of WMSNs with increased network throughput at the cost of a small control and energy overhead.

ENERGY EFFICIENT DISTRIBUTED STEGANOGRAPHY FOR SECURE COMMUNICATION IN WIRELESS MULTIMEDIA SENSOR NETWORKS

A secure communication mechanism is necessary in the applications of Wireless Multimedia Sensor Networks (WMSNs), which is more vulnerable to security attacks due to the presence of multimedia data. Additionally, given the limited technological resources (in term of energy, computation, bandwidth, and storage) of sensor nodes, security and privacy policies have to be combined with energy-aware algorithms and distributed processing of multimedia contents in WMSNs. To solve these problems in this paper, an energy efficient distributed steganography scheme, which combines steganography technique with the concept of distributed computing, is proposed for secure communication in WMSNs. The simulation results show that the proposed method can achieve considerable energy efficiency while assuring the communication security simultaneously.

Enhanced Metaheuristics-Based Clustering Scheme for Wireless Multimedia Sensor Networks

Traditional Wireless Sensor Networks(WSNs)comprise of costeffective sensors that can send physical parameters of the target environment to an intended user.With the evolution of technology,multimedia sensor nodes have become the hot research topic since it can continue gathering multimedia content and scalar from the target domain.The existence of multimedia sensors,integrated with effective signal processing and multimedia source coding approaches,has led to the increased application of Wireless Multimedia Sensor Network(WMSN).This sort of network has the potential to capture,transmit,and receive multimedia content.Since energy is a major source in WMSN,novel clustering approaches are essential to deal with adaptive topologies of WMSN and prolonged network lifetime.With this motivation,the current study develops an Enhanced Spider Monkey Optimization-based Energy-Aware Clustering Scheme(ESMO-EACS)for WMSN.The proposed ESMO-EACS model derives ESMO algorithm by incorporating the concepts of SMO algorithm and quantum computing.The proposed ESMO-EACS model involves the design of fitness functions using distinct input parameters for effective construction of clusters.A comprehensive experimental analysis was conducted to validate the effectiveness of the proposed ESMO-EACS technique in terms of different performance measures.The simulation outcome established the superiority of the proposed ESMO-EACS technique to other methods under various measures.

Clustering in Wireless Multimedia Sensor Networks Using Spectral Graph Partitioning

Wireless multimedia sensor network (WMSN) consists of sensors that can monitor multimedia data from its surrounding, such as capturing image, video and audio. To transmit multimedia information, large energy is required which decreases the lifetime of the network. In this paper we present a clustering approach based on spectral graph partitioning (SGP) for WMSN that increases the lifetime of the network. The efficient strategies for cluster head selection and rotation are also proposed.

Clustering in Wireless Multimedia Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs) are comprised of small embedded audio/video motes capable of extracting the surrounding environmental information, locally processing it and then wirelessly transmitting it to sink/base station. Multimedia data such as image, audio and video is larger in volume than scalar data such as temperature, pressure and humidity. Thus to transmit multimedia information, more energy is required which reduces the lifetime of the network. Limitation of battery energy is a crucial problem in WMSN that needs to be addressed to prolong the lifetime of the network. In this paper we present a clustering approach based on Spectral Graph Partitioning (SGP) for WMSN that increases the lifetime of the network. The efficient strategies for cluster head selection and rotation are also proposed as part of clustering approach. Simulation results show that our strategy is better than existing strategies.

Streaming Multimedia over Wireless Mesh Networks

Wireless mesh network (WMN) research is an emerging field in network communications. However, WMNs pose several difficulties in the transmission of information, especially time critical applications such as streaming video and audio. In this paper, we provide an overview of several research papers which utilize mesh networks for streaming multimedia. We compare the results of the research and the significance they bring to the field of wireless mesh networks. We then provide possible directions for future research into wireless mesh networks as they apply to streaming multimedia.

A Sensor Awakening Algorithm for Wireless Multimedia Sensor Networks Three Dimensional Target Tracking

For node awakening in wireless multi-sensor networks, an algorithm is put forward for three dimensional tar- get tracking. To monitor target dynamically in three dimensional area by controlling nodes, we constract vir- tual force between moving target and the current sense node depending on the virtual potential method, then select the next sense node with information gain function, so that when target randomly move in the specific three dimensional area, the maximum sensing ratio of motion trajectory is get with few nodes. The proposed algorithm is verified from the simulations.

A time domain multiple-CFOs and CIRs estimation algorithm over wireless multimedia sensor networks

Channel parameters estimation in an orthogonal frequency division multiple access(OFDMA)systemfor the receiver station is a multi-dimensional(MD)optimization problem,because every user node has aseparate local oscillator and every transmitter to receiver link has individual carrier frequency offset(CFO)and channel impulse response(CIR)parameters .In order to reduce the computational complexityfor MD optimization,a time domain CFOs and CIRs estimation algorithm over the OFDMA based wirelessmultimedia sensor networks(WMSN)is proposed in this paper.In this algorithm,the receiver stationcan decouple the signal from every node by correlation based on specially designed training sequences,sothat the MD optimization problem is simplified to an 1-D optimal problem.It is proved that the multipleCFOs can be identified from the correlation result using the phase shift of the consecutive training se-quences .Based on the CFOs estimation result,the CIRs can then be estimated according to the minimummean square error(MMSE)criterion.The theoretic analysis and simulation results show that the proposedalgorithm can effectively decouple the signal from different user nodes and the bit error rate(BER)per-formance curves are close to the ideal estimation when the user number is not large.

Multimedia Streaming for Ad Hoc Wireless Mesh Networks Using Network Coding

Over the past years, we have witnessed an explosive growth in the use of multimedia applications such as audio and video streaming with mobile and static devices. Multimedia streaming applications need new approaches to multimedia transmissions to meet the growing volume demand and quality expectations of multimedia traffic. This paper studies network coding which is a promising paradigm that has the potential to improve the performance of networks for multimedia streaming applications in terms of packet delivery ratio (PDR), latency and jitter. This paper examines several network coding protocols for ad hoc wireless mesh networks and compares their performance on multimedia streaming applications with optimized broadcast protocols, e.g., BCast, Simplified Multicast Forwarding (SMF), and Partial Dominant Pruning (PDP). The results show that the performance increases significantly with the Random Linear Network Coding (RLNC) scheme.

Queuing Management in Wireless Sensor Networks for QoS Measurement

Data transmission in multimedia WSNs are required high bandwidth and reliable transfer because of large amount of data size. However, some applications of WSNs are required high quality. In this context, main factor in quality of services (QoS) metrics in WSNs becomes longevity of the network and high quality. In sensor nodes, choosing relevant transceiver and microcontroller components plays important role in assembling sensor devices, in which data controls should be designed so that packet loss is minimized. Available QoS metrics based on queuing/buffer management in wired and other wireless networks don’t applicable in WSNs because of its unique characteristics. In this paper the simplest model of QoS model-bufferless system were proposed. In the proposed model, measurement of the probability of blocking of the arrival packets was suggested by using queuing theory in order to increase QoS. Given probability of blocking (PB) illustrates clear picture how system specification should be chosen so that blocking state would be minimized.

Energy Efficient and QoS Aware Framework for Video Transmission over Wireless Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs), is a network of sensors, which are limited in terms of memory, computing, bandwidth, and battery lifetime. Multimedia transmission over WSN requires certain QoS guarantees such as huge amount of bandwidth, strict delay and lower loss ratio that makes transmitting multimedia is a complicated task. However, adopting cross-layer approach in WMSNs improves quality of service of WSN under different environmental conditions. In this work, an energy efficient and QoS aware framework for transmitting multimedia content over WSN (EQWSN) is presented, where packet, queue and path scheduling were introduced. It adapts the application layer parameter of video encoder to current wireless channel state, and drops less important packets in case of network congestion according to packet type. Finally, the path scheduling differentiates packets types/priority and route them through different paths with different QoS considering network lifetime. Simulation results show that the new scheme EQWSN transmits video quality with QoS guarantees in addition to prolonging network lifetime.

Three-Dimensional Dynamic Based Borrowing Scheme for Wireless Cellular Networks

Mobility metrics of wireless networks such as link availability, number of neighboring nodes, link duration, link state, and link stability make it difficult to provide a node with quality of services guarantee. In previous research on Quality of Service (QoS) for cellular networks especially for handling handoff connections, the design was based on a flat 2D hexagon cells. However, in reality Base Station antenna coverage is in a 3D space and there exists a blind spot;the area which is just above and bellow the radiated antenna. In this paper we introduce the concept of Blind Spot (BS) in which there is no signals to initiate a call or accepting a handoff one. In BS, the signal power equal zero. Even if there is enough bandwidth to initiate or accept a handoff call, it will be blocked or dropped respectively. We present an implementation of Static Borrowing Scheme (SBS) and we extend the dynamic-rate based borrowing scheme [1] into 3-Dimentional structure and call it 3-Dimensional Dynamic Based Borrowing Scheme (3D DBBS). The proposed new technique for resource sharing is to ensure the continuity for both originating and handoff connections in 3-D cellular networks based on Dynamic-Based Borrowing Scheme (3D BBS). This technique aims to minimize the blocking probability of the originating calls by minimizing the dropping probability of the handoff requests and maximizing the channel utilization. The results revealed that 3D DBBS outperformed the static based schemes by 5% on average even when the blind spot of the base station antenna is taken into consideration. When moving to a 3D space, the results of the simulation showed the 3D DBBS outperformed the static scheme by 2% on average. As a result, considering nodes in a 3D space will have better QoS guarantee as the blocking and dropping probabilities are decreased. Thus, the bandwidth utilization is increased.

基于蝗虫算法的配电通信WMSNs多路径QoS路由优化模型研究

为提高配电通信网络的生命周期,降低网络能耗和均衡化WMSNs多路径QoS路由网络负荷,提出一种基于配电通信网的蝗虫算法优化WMSNs多路径QoS路由算法研究。选择WMSNs多路径QoS路由路径最短和能量最低为目标函数。研究结果表明,与改进算法和经典算法相比,基于GOA的WMSNs多路径QoS路由算法网络能耗最低、死亡节点数最少,效果很好,可以延长死亡节点产生的时间,有效提高整个WMSNs多路径QoS路由网络的生存寿命。

基于跨层设计的无线网络通信多媒体传输技术研究

针对无线网络通信在数据分组传送阶段存在的通信冗余问题,文章提出一种新颖的网络编码和跨层设计相结合的高效路由算法,以根据各种服务质量约束混合网络吞吐量,例如:无线多播速率、无线链路容量、能量供应和网络寿命。具体而言,本研究开发了一种基于NC的启发式链路控制路由树算法,以减少所需的中间节点的数量。该算法通过新颖的跨层设计,有利于优化无线组播速率、无线链路数据流、能量供应和节点寿命。设计实验对提出的算法进行验证,结果表明,所提出的方案可以较为明显地提高整个无线传感器网络的通信性能。

Node correlation clustering algorithm for wireless multimedia sensor networks based on overlapped FoVs

In this paper, a clustering algorithm is proposed based on the high correlation among the overlapped field of views for the wireless multimedia sensor networks. Firstly, by calculating the area of the overlapped field of views （FoVs） based on the gird method, node correlations have been obtained. Then, the algorithm utilizes the node correlations to partition the network region in which there are high correlation multimedia sensor nodes. Meanwhile, in order to minimize the energy consumption for transmitting images, the strategy of the cluster heads election is proposed based on the cost estimation, which consists of signal strength and residual energy as well as the node correlation. Simulation results show that the proposed algorithm can balance the energy consumption and extend the network lifetime effectively.

Novel congestion control approach in wireless multimedia sensor networks

Data generated in wireless multimedia sensor networks （WMSNs） may have different importance and it has been claimed that the network exert more efforts in servicing applications carrying more important information. Nevertheless, importance of packets cannot generally be accurately represented by a static priority value. This article presents a dynamic priority based congestion control （DPCC） approach that makes two major innovations in WMSNs. First, DPCC employs dynamic priority to represent packet importance. Second, it prioritizes the local traffic of motes near the base station when WMSN is highly congested. Simulation results confirm the superior performance of the proposed approach with respect to energy efficiency, loss probability and latency as well.

基于跨层设计的无线网络通信多媒体传输技术研究

针对无线网络通信在数据分组传送阶段存在的通信冗余问题,提出了一种新颖的网络编码和跨层设计相结合的高效路由算法,以根据各种服务质量约束混合网络吞吐量。文章开发了一种基于NC的启发式链路控制路由树算法,以减少所需的中间节点的数量。该算法通过新颖的跨层设计,有利于优化无线组播速率、无线链路数据流、能量供应和节点寿命。最后设计实验对提出的算法进行验证,结果表明,所提出的方案可以较为明显地提高整个无线传感器网络的通信性能。

基于方差的WMSN图像非均匀分块自适应压缩算法

针对无线多媒体传感器网络数据量较大和储存能力有限等问题,提出了基于方差的图像非均匀分块自适应压缩算法。在传统的压缩方法中,均匀分块的稀疏变换对图像信号进行压缩,会带来图像重构的块状效应,而且无法有效地分离出重要区域或者背景区域。给出一种基于方差的图像非均匀分块自适应压缩算法,以图像方差值作为块大小分割依据,利用四叉树算法进行图像块大小的划分。并将分块大小结果分成快速变化块、过度块和缓慢变化块3类,适时做不同程度的压缩。实验结果表明:本文所提出的算法在图像重构质量方面优于传统的均匀分块压缩方法。

无线多媒体网络拓扑信息并发获取模型构建

当前网络拓扑信息并发获取模型目标一般为独立形式,并发获取范围受限制,导致并发获取处理频次下降。为解决这个问题,文章提出构建无线多媒体网络拓扑信息并发获取模型。通过设计并发获取信息组织,设定多阶模型目标,构建交互式拓扑信息并发获取结构,采用异步处理实现并发获取模型应用。测试结果表明,所设计模型的并发获取频次可保持在14次以上,应用效果得到了明显提升,具有实际的应用价值。