In-Network Puncturing for Delay-Efficient Rate Control of Distributed Video Coding in Wireless Video Sensor Networks

Wyner-Ziv Video Coding (WZVC) is considered as a promising video coding scheme for Wireless Video Sensor Networks (WVSNs) due to its high comp ression efficiency and error resilience functionalities, as well as its low encoding comp lexity. To achieve a good Rate-Distortion (R-D) performance, the current WZVC paradigms usually adopt an end-to-end rate control scheme in which the decoder rep eatedly requests the additional decoding data from the encoder for decoding Wyner-Ziv frames. Therefore, the waiting time of the additional decoding data is esp ecially long in multihop WVSNs. In this paper, we propose a novel progressive in-network rate control scheme for WZVC. The proposed in-network puncturing-based rate control scheme transfers the partial channel codes puncturing task from the encoder to the relay nodes. Then, the decoder can request the additional decoding data from the relay nodes instead of the encoder, and the total waiting time for decoding Wyner-Ziv frames is reduced consequently. Simulation results validate the proposed rate control scheme.

Hierarchical Scene Analysis Method for Audio Sensor Networks

A hierarchical method for scene analysis in audio sensor networks is proposed.This method consists of two stages:element detection stage and audio scene analysis stage.In the former stage,the basic audio elements are modeled by the HMM models and trained by enough samples off-line,and we adaptively add or remove basic element from the targeted element pool according to the time,place and other environment parameters.In the latter stage,a data fusion algorithm is used to combine the sensory information of the same area,and then,a rule-based method is employed to analyze the audio scene based on the fused data.We conduct some experiments to evaluate the performance of the proposed method that about 70% audio scenes can be detected correctly by this method.The experiment evaluations demonstrate that our method can achieve satisfactory results.

Environmental Sound Event Detection in Wireless Acoustic Sensor Networks for Home Telemonitoring

In this paper, we present an approach to improve the accuracy of environmental sound event detection in a wireless acoustic sensor network for home monitoring. Wireless acoustic sensor nodes can capture sounds in the home and simultaneously deliver them to a sink node for sound event detection. The proposed approach is mainly composed of three modules, including signal estimation, reliable sensor channel selection, and sound event detection. During signal estimation, lost packets are recovered to improve the signal quality. Next, reliable channels are selected using a multi-channel cross-correlation coefficient to improve the computational efficiency for distant sound event detection without sacrificing performance. Finally, the signals of the selected two channels are used for environmental sound event detection based on bidirectional gated recurrent neural networks using two-channel audio features. Experiments show that the proposed approach achieves superior performances compared to the baseline.

Study on an Audio and Video Network Monitoring System for Weather Modification Operation

An audio and video network monitoring system for weather modification operation transmitting information by 3G, ADSL and Internet has been developed and applied in weather modification operation of Tai＇an City. The all-in-one machine of 3G audio and video network highly integrates all front-end devices used for audio and video collection, communication, power supply and information storage, and has advantages of wireless video transmission, clear two-way voice intercom with the command center, waterproof and dustproof function, simple operation, good portability, and long working hours. Compression code of the system is transmitted by dynamic bandwidth, and compression rate varies from 32 kbps to 4 Mbps under different network conditions. This system has forwarding mode, that is, monitoring information from each front-end monitoring point is trans- mitted to the server of the command center by 3G/ADSL, and the server codes＇and decodes again, then beck-end users call images from the serv- er, which can address 3G network stoppage caused by many users calling front-end video at the same time. In addition, the system has been ap- plied in surface weather modification operation of Tai＇an City, and has made a great contribution to transmitting operation orders in real time, monitoring, standardizing and recording operating process, and improving operating safety.

Predictive Block-Matching Algorithm for Wireless Video Sensor Network Using Neural Network

This paper proposed a back propagation neural network model for predictive block-matching. Predictive block-matching is a way to significantly decrease the computational complexity of motion estimation, but the traditional prediction model was proposed 26 years ago. It is straight forward but not accurate enough. The proposed back propagation neural network has 5 inputs, 5 neutrons and 1 output. Because of its simplicity, it requires very little calculation power which is negligible compared with existing computation complexity. The test results show 10% - 30% higher prediction accuracy and PSNR improvement up to 0.3 dB. The above advantages make it a feasible replacement of the current model.

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.

Mobile Positioning System Based on the Wireless Sensor Network in Buildings

Established on the Intel Multi-Core Embedded platform, using 802.11 Wireless Network protocols as the communication medium, combining with Radio Frequency-Communication and Ultrasonic Ranging, imple-ment a mobile terminal system in an intellectualized building. It can provide its holder such functions: 1) Accurate Positioning 2) Intelligent Navigation 3) Video Monitoring 4) Wireless Communication. The inno-vative point for this paper is to apply the multi-core computing on the embedded system to promote its com-puting speed and give a real-time performance and apply this system into the indoor environment for the purpose of emergent event or rescuing.

天津市地震局应急视频会议系统组网研究

为全面提升地震应急指挥能力和协同应急通讯效率,天津市地震局应急指挥大厅基于跨网段多层级视频融合技术完善天津市地震应急视频指挥调度网络,构建“平战结合”双模式。通过探究跨网段通讯、多层级音视频信号转发、多点控制单元(MCU)级联等技术,实现天津局与中国局、市政府、市应急管理局以及辖区内各应急视频节点互连互通,为天津市地震应急快速响应提供高效的通信保障。

电声信号编解码技术在网络多媒体传输中的应用

探讨电声信号编解码技术在网络多媒体传输中的应用,重点分析音频、语音、视频编解码的原理和关键技术。通过实际案例剖析,揭示了编解码技术在复杂网络环境下的优化措施,如自适应码率控制、智能分路由、错误恢复机制等,有效提升了多媒体传输的质量和稳定性。

超高清视音频IP流调度切换技术及应用研究

新形势下我国的信息技术发展迅速,与媒体领域的融合度加深,推动了广播电视超高清化发展。在网络直播技术和5G技术的支持下,广播电视台尝试以网际互连协议(Internet Protocol,IP)化的形式,实现IP信号的高效交换。基于此,主要探讨超高清视音频IP流调度切换技术及其应用实践,以期为相关人员提供借鉴,满足信号调度IP化转型需求,推动广播电视行业实现可持续发展。

指挥中心高清音视频调度系统运维保障研究

高清音视频调度系统是保障人民防空指挥中心开展防空袭作战指挥和召开各类电视电话会议的重要系统平台。因此,如何对系统进行高效保障是每位保障人员面临的课题。本文首先针对怎样提高指挥中心高清音视频调度系统运维保障能力进行了探索研究,然后从系统构成、设计要点、测试与维护等方面,详细阐述了高清音视频调度系统运维保障各环节的监控、管理问题,最后提出相关运维保障方案,旨在为今后工作提供指导与参考。

Research on tasks schedule and data transmission of video sensor networks based on intelligent agents and intelligent algorithms

As a novel application technology,wireless video sensor networks become the current research focus,especially on target tracking and surveillance scenario.Based on multiple agents＇ technique,this article introduces a series of intelligent algorithms such as simulated annealing algorithm（SA）,genetic algorithm（GA）,and ant colony optimization algorithm（ACO） or their mixed algorithms,to resolve the optimization of tasks schedule and data transmission.This article analyzes the performance of abovementioned algorithms and verifies their feasibility associated with agents.The simulations demonstrates that the mixed algorithms based on SA and GA obtain the optimal solution to tasks schedule,and those combined with SA-ACO show advantages on multimedia sensor networks routing optimization.

一种矿用本安型音视频记录仪

设计了一种矿用本安型音视频记录仪。设备基于5G SOC处理器,采用感光传感器+白光/红外激光补光+本质安全电路方案,在低照度、全黑或密闭空间的环境下,能采集、压缩、存储、显示4K高清视频图像,同时将采集的音视频数据进行实时远传;记录仪具有低照度环境下成像质量高、拍摄距离远、功耗小等特点,支持TCP/IP、UDP、RTP、ONVIF、GB28181等协议,除了作为井下信息记录外,还可以辅助应急指挥部及时展开救援行动。测试结果表明:记录仪黑暗环境下图片分辨率为10688×6012,视频分辨率为2560×1440,可视距离达20 m,数据丢包率约为0.068%,时延约为15.85 ms,可实现持续视频摄录9 h或持续视频回传4 h。

基于WSN的幼儿园监测系统设计

为提高幼儿园办园质量和管理水平,进一步加强安全管理、消除安全隐患、为幼儿提供安全的成长环境,文章设计了基于无线传感器网络技术、射频识别技术的幼儿园监测系统,通过3个部分解决幼儿园的监测问题。该系统同时解决了监测教室环境参数的问题,家长可登录网页实时查看孩子的在校视频。

Dante网络音频传输协议在视频会议上的应用

2021年,某政务单位在升级视频会议系统时采用了Dante网络音频传输技术,提供了一种整体解决方案。该技术在以太网(Ethernet)网络中能够同时发送和接收多个音频通道。Dante音频传输无杂音、传输速度快、精度高且成本低,点对点传输基本接近于零延迟,通常可以通过双绞网线替代音频线路,节省成本。同时,Dante技术可以通过网络层以网际协议(Internet Protocol,IP)的形式实现音频通信,使得音频数据与会议相关数字信号互不干扰,兼容不同型号的音频设备。通过Dante网络音频传输技术的实施,解决了音频在项目实施期间的很多难题。

配网供电服务指挥智慧音视频通信系统的设计与实现

现代配网调控面临异地沟通不畅、业务忙闲不均、应急协同支援能力受限等问题。文章基于电力能源互联网概念,提出了“双全”(全视频调度+全区一号通)智慧音视频通信系统,将原来零散分布的配网调度音视频通信基础资源进行有机融合与互联,采用“云端服务+边缘协同”基础架构原则,有效优化系统通信资源整体配置,做到“万物互联互动”,大力提升调度员日常业务在线沟通效率与灾害应急协同指挥处置能力,助力提升地区配电网故障快速复电能力与集群化运行指挥管控水平。

载人航天器天地视频/音频通信网络一体化设计

天地视频/音频通信在载人航天任务中具有重要的作用。为实现天地视频/音频通信,针对载人航天器与地面通信站之间通信链路时延长和前向/返向链路速率不对称的特点,提出一种天地视频/音频通信网络一体化设计。采用国际空间数据系统咨询委员会(CCSDS)的IP技术(IP over CCSDS技术)实现视频/音频数据天地一体化传输;针对不同类型、不同优先级的数据,采用静态优先级和轮询调度策略相结合的调度方式,以保证业务传输需求。采用信道编码、加扰和加同步字的方式,保证天地视频/音频传输的服务质量(QoS)。文章提出的天地视频/音频通信网络一体化设计,经过地面试验和在轨飞行验证,结果表明:视频数据传输速率均匀,图像话音清晰无卡顿,均未发生丢包,可用于低轨载人航天器与地面站的通信,也可为后续载人登月、载人登火等深空领域任务提供参考。

智能全景视觉传感网络视频多目标跟踪仿真

传统视频多目标方法忽略了对网络视频多目标状态的核验,导致出现效率偏低、误差较大等问题。提出智能全景视觉传感网络视频多目标跟踪方法。利用卷积神经网络,分割网络视频图像多目标跟踪信息,通过选择网络视频图像多目标特征,得到网络视频图像的投影矩阵。基于网络视频图像中多目标特征的状态,核验多网络视频多目标状态,以特征函数的状态作为当前网络视频图像的目标特征,将传感网络视频多目标特征作为状态向量,计算并归一化处理状态向量的权值。通过智能全景视觉传感网络中每个视频对应的图像,检测出多目标元素,关联状态向量权值和目标位置,完成网络视频多目标的跟踪。实验结果表明,所提多目标跟踪方法具有较高的多目标跟踪成功率和正确率,增强了多目标跟踪效果。

基于信息接入终端的音视频显控3.0系统设计

结合现代化指挥大厅的显控需求,应用网络传输技术和流媒体编解码等技术,提出基于信息接入终端的音视频显控3.0系统方案。从系统的技术体制、业务功能及优势出发,详细介绍系统的核心组成和体系结构,阐述系统的关键技术。经多个项目实际验证,该设计既保证了系统功能实现的可靠性,又有效缩短了工程项目实施周期,实现了指挥大厅的简洁化布线、灵活化部署、模块化拼装以及智能化运维,可为其他指挥大厅项目提供相应参考。