Towards Interference-Aware ZigBee Transmissions in Heterogeneous Wireless Networks

Cross-technology interference(CTI)from diverse wireless networks such as ZigBee,Bluetooth,and Wi-Fi has become a severe problem in the 2.4 GHz Industrial Scientific and Medical(ISM)band.Especially,low power and lossy networks are vulnerable to the signal interferences from other aggressive wireless networks when they perform low power operations to conserve the energy consumption.This paper presents CoSense,which accurately detects ZigBee signals with a reliable signal correlation scheme in the presence of the CTI.The key concept of CoSense is to reduce false wake-ups of low power listening(LPL)by identifying the pre-defined ZigBee signatures.Our scheme is robust in the coexistence environment of diverse wireless technologies since the signal correlation works well in bad wireless channel conditions.It achieves standard compliance and transparency without any hardware and firmware changes.We have implemented CoSense on the Universal Software Radio Peripheral(USRP)platform to verify its feasibility.The experimental exploration reveals that CoSense significantly reduces the false-positive and false-negative rate under typical setting and the additional overhead is negligible.The results show that our scheme saves much energy by up to 63%in dynamic network interference scenarios where low-power ZigBee transmissions are overwhelmed by strong Wi-Fi signal interferences.

Design of Wireless Multi-media Sensor Network for Precision Agriculture

To satisfy the needs of modem pre-cision agriculture, a Precision Agriculture Sensing System （PASS） is designed, which is based on wireless multimedia sensor network. Both hardware and software of PASS are tai-lored for sensing in wide farmland without human supervision. A dedicated single-chip sensor node platform is designed specially for wireless multi-media sensor network. To guarantee the bulky data transmission, a bit-map index reliable data transmission mecha-nism is proposed. And a battery-array switch-ing system is design to power the sensor node to elongate the lifetime. The effectiveness and performance of PASS have been evaluated through comprehensive experiments and large-scale real-life deployment.

A low-power Bluetooth-based wireless sensor network and its global confliction-solving impact localization method

During the whole service lifetime of aircraft structures with composite materials,impacts are inevitable and can usually cause severe but barely visible damages.Since the occurrences of impact are random and unpredictable,it is a hotspot direction to develop an online impact monitoring system that can meet strict limitations of aerospace applications including small size,light weight,and low power consumption.Piezoelectric(PZT)sensor,being able to generate impact response signals with no external power and cover a large-scale structure with only a small amount of them,is a promising choice.Meanwhile,for real systems,networks with multiple nodes are normally required to monitor large-scale structures in a global way to identify any impact localization confliction,yet the existing studies are mostly evaluated with single nodes instead of networks.Therefore,in this paper,based on a new low-power node designed,a Bluetooth-based digital impact monitoring PZT sensor network is proposed for the first time with its global confliction-solving impact localization method.Evaluations of the system as a network are researched and analyzed on a complex real aircraft wing box for a global confliction-solving impact localization,showing a satisfying high accuracy.

An Internet of Energy Things Based on Wireless LPWAN

Under intense environmental pressure, the global energy sector is promoting the integration of renewable energy into interconnected energy systems. The demand-side management （DSM） of energy systems has drawn considerable industrial and academic attention in attempts to form new flexibilities to respond to variations in renewable energy inputs to the system. However, many DSM concepts are still in the experimental demonstration phase. One of the obstacles to DSM usage is that the current information infrastructure was mainly designed for centralized systems, and does not meet DSM requirements. To overcome this barrier, this paper proposes a novel information infrastructure named the lnternet of Energy Things （IoET） in order to make DSM practicable by basing it on the latest wireless communication technology： the low-power wide-area network （LPWAN）. The primary advantage of LPWAN over general packet radio service （GPRS） and area Internet of Things （loT） is its wide-area coverage, which comes with minimum power consumption and maintenance costs. Against this background, this paper briefly reviews the representative LPWAN tech- nologies of narrow-band Internet of Things （NB-IoT） and Long Range （LORa） technology, and compares them with GPRS and area IoT technology. Next, a wireless-to-cloud architecture is proposed for the IoET, based on the main technical features of LPWAN. Finally, this paper looks forward to the potential of IoET in various DSM application scenarios.

LOA-RPL:Novel Energy-Efficient Routing Protocol for the Internet of Things Using Lion Optimization Algorithm to Maximize Network Lifetime

Energy conservation is a significant task in the Internet of Things(IoT)because IoT involves highly resource-constrained devices.Clustering is an effective technique for saving energy by reducing duplicate data.In a clustering protocol,the selection of a cluster head(CH)plays a key role in prolonging the lifetime of a network.However,most cluster-based protocols,including routing protocols for low-power and lossy networks(RPLs),have used fuzzy logic and probabilistic approaches to select the CH node.Consequently,early battery depletion is produced near the sink.To overcome this issue,a lion optimization algorithm(LOA)for selecting CH in RPL is proposed in this study.LOA-RPL comprises three processes:cluster formation,CH selection,and route establishment.A cluster is formed using the Euclidean distance.CH selection is performed using LOA.Route establishment is implemented using residual energy information.An extensive simulation is conducted in the network simulator ns-3 on various parameters,such as network lifetime,power consumption,packet delivery ratio(PDR),and throughput.The performance of LOA-RPL is also compared with those of RPL,fuzzy rule-based energyefficient clustering and immune-inspired routing(FEEC-IIR),and the routing scheme for IoT that uses shuffled frog-leaping optimization algorithm(RISARPL).The performance evaluation metrics used in this study are network lifetime,power consumption,PDR,and throughput.The proposed LOARPL increases network lifetime by 20%and PDR by 5%–10%compared with RPL,FEEC-IIR,and RISA-RPL.LOA-RPL is also highly energy-efficient compared with other similar routing protocols.

Unweighted Voting Method to Detect Sinkhole Attack in RPL-Based Internet of Things Networks

The Internet of Things(IoT)consists of interconnected smart devices communicating and collecting data.The Routing Protocol for Low-Power and Lossy Networks(RPL)is the standard protocol for Internet Protocol Version 6(IPv6)in the IoT.However,RPL is vulnerable to various attacks,including the sinkhole attack,which disrupts the network by manipulating routing information.This paper proposes the Unweighted Voting Method(UVM)for sinkhole node identification,utilizing three key behavioral indicators:DODAG Information Object(DIO)Transaction Frequency,Rank Harmony,and Power Consumption.These indicators have been carefully selected based on their contribution to sinkhole attack detection and other relevant features used in previous research.The UVM method employs an unweighted voting mechanism,where each voter or rule holds equal weight in detecting the presence of a sinkhole attack based on the proposed indicators.The effectiveness of the UVM method is evaluated using the COOJA simulator and compared with existing approaches.Notably,the proposed approach fulfills power consumption requirements for constrained nodes without increasing consumption due to the deployment design.In terms of detection accuracy,simulation results demonstrate a high detection rate ranging from 90%to 100%,with a low false-positive rate of 0%to 0.2%.Consequently,the proposed approach surpasses Ensemble Learning Intrusion Detection Systems by leveraging three indicators and three supporting rules.

无线通讯技术及其在物探生产作业中的适用性分析

随着地震勘探采集作业效率要求不断提高,对于现场信息化程度的需求也随之增加。在应用技术开发如何选择性能最适合的无线通讯模块,逐渐成为摆在业内技术人员面前的难题。功耗、体积、成本、带宽等因素要根据现场应用需求均衡考虑抉择。本文就随着物联网发展不断推出的一些无线通讯技术与传统无线网络技术进行简单对比,以期对专业应用技术人员在开发过程中提供参考。

基于6LoWPAN的物联网寻址策略研究

在6LoWPAN(IPv6 over Low-power Wireless Personal Area Network)的基础上,该文提出应用于物联网的寻址策略,实现基于IEEE 802.15.4协议的底层异构网络与互联网的实时通信。寻址策略包括IPv6地址自动配置和报头压缩。采用的分层地址自动配置策略,首先在底层网络内部允许节点使用16位短地址导出的链路本地地址进行数据分组传输,该链路本地地址需通过执行基于分簇的重复地址检测机制保证唯一性;其次,每个底层网络中的Sink节点通过上层IP路由器获取全球路由前缀,并与接口标识符相结合,形成Sink节点的全球地址,实现底层网络与互联网的数据交换。同时,通过在报头压缩编码中植入链路本地地址和全球地址控制位,提出了一种适用于物联网应用的报头压缩方案IIPHC(IoTs IPv6 Header Compression)。如果地址类型为链路本地地址,则采用简单灵活的IIPHC1方案,如果地址类型为全球地址,则采用相对复杂但有效的IIPHC2方案。仿真及测试结果表明,基于6LoWPAN的物联网寻址策略在网络开销、时延、吞吐量、能耗等性能方面存在一定的优越性。

基于低功耗广域网的海岛水产养殖环境监测系统研制

针对海岛环境中水产养殖区域分散、工作环境恶劣、人工巡检不便等问题,设计了基于低功耗广域物联网的海岛养殖环境监测系统。系统包括集成Arduino和传感器的终端采集节点,通过LoRa技术实现数据汇总和远距离传输的汇聚网关,利用Python与PostgreSQL开发用于数据接收、存储、处理、访问和控制的后台监测系统。通过对网络拓扑复杂度、能耗等方面的评估,表明在海岛环境下部署水产养殖环境监测系统,相比传统Zigbee多跳无线传感网,采用LoRaWAN,其单跳节点覆盖范围更大,而网络复杂度、能耗等更优。测试表明该系统能以较低功耗实现整片区域内远距离数据采集,有效传输养殖区水体环境数据。网络生存期与传输可靠性测试表明,当传感器节点采用3.7 V/4 200 mAh锂电池,上传周期为30 min时,监测网络的有效生存期理论上可达2.4 a;在800 m通信范围内,发射功率为20 mW时,节点丢包率小于3.6%,具有较高的通信可靠性。该研究可为水产养殖生产和物联网应用研究提供有效参考。

地下LoRa无线传感器网络的传输测试系统研究

【目的】以智能手机为核心,研制成本低、使用简单的面向LoRa地下无线数据传输的测试系统。【方法】该测试系统由安装了测试用的App智能手机和与之匹配的地下测试节点组成。利用该系统进行场景测试,测定影响土壤中LoRa无线数据传输效果的因素并讨论对应的数据传输方法。【结果】测试结果表明,该系统运行可靠、使用方便灵活,LoRa低功耗广域网技术亦可以较为可靠地满足土壤介质中的无线传感器网络数据传输需求。【结论】本系统可为未来地下LoRa无线传感器网络的工程应用提供相应的测试手段。

基于智能手机的LoRa无线传输效能测试研究

基于LoRa的低功耗广域网技术有望成为未来物联网的主干支撑技术之一。为了给工作在不同应用环境中的LoRa无线传感器网络节点间的传输提供简单有效、易于使用、成本低廉的测试手段,提出一种基于智能手机的LoRa无线传输效能测试系统。该系统由智能手机及与之配套的低成本测试节点组成。对组成系统的智能手机端App及测试节点设计进行讨论,系统完成后利用其在智能楼宇与智慧农业的应用场景下进行测试。测试结果表明,LoRa无线传输在不同的应用环境中会受到外界因素的干扰,通过本系统可方便、有效、快捷地获得分散在较长时间周期内的数据,为基于LoRa的无线传感器网络在设计、安装与维护中提供以数据传输效果为表征的参考测试数据。

基于LoRa与可编程片上系统的纺织设备无线数传节点

为满足纺织企业设备信息化、智能化升级中对无线数据传输的需求,基于LoRa技术,并结合可编程片上系统,设计一种可用于纺织设备的无线数传节点。该节点具有功能伸缩性强、传输效果好、使用方便、网络拓扑简洁、面向设备开发维护便捷、电磁隔离效果好、成本低廉等优点。测试结果表明,该无线数传节点可以有效地作为纺织企业中设备无线信息交互的手段。

物联网LoRa技术的应用与发展

LoRa器件和无线射频技术是一种近几年被广泛采用的远距离、低功耗物联网解决方案,该技术支持电信公司、物联网应用开发商和系统集成商在全球部署低成本且互通的物联网网络、网关、传感器、模组产品和物联网服务,并提供了所需的功能组合。本文从LoRa技术原理开始,描述了技术概念和总结了其技术特点,并介绍现阶段LoRa技术在多个领域的应用方式,以及此项技术近几年在国内外的发展过程。

Experimental Analysis of Link Estimation Methods in Low Power Wireless Networks

Wireless sensor networks are envisioned to be an integral part of cyber-physical systems, yet wireless networks are inherently dynamic and come with various uncertainties. One such uncertainty is wireless communication itself which assumes complex spatial and temporal dynamics. For dependable and predictable performance, therefore, link estimation has become a basic element of wireless network routing. Several approaches using broadcast beacons and/or unicast MAC feedback have been proposed in the past years, but there is still no systematic characterization of the drawbacks and sources of errors in bea- con-based link estimation in low-power wireless networks, which leads to ad hoc usage of beacons in rout- ing. Using a testbed of 98 XSM motes （an enhanced version of MICA2 motes）, we characterize the negative impact that link layer retransmission and traffic-induced interference have on the accuracy of beacon-based link estimation, and we show that data-driven link estimation and routing achieve higher event reliability （e.g. by up to 18.75%） and transmission efficiency （e.g., by up to a factor of 1.96） than beacon-based approaches These findings provide solid evidence for the necessity of data-driven link estimation and demonstrate the importance of addressing the drawbacks of beacon-based link estimation when designing protocols for low-power wireless networks of cyber-physical systems.

某高校智慧供热改造试点的电气系统设计

针对建筑供热系统的节能改造,采用智慧供热控制系统,在建筑物热力入口处加装调节装置及计量装置、设置分时供暖、根据室外气象条件进行调节、采取供热按实际使用热量计费方式。

无线数传技术在远距离数据通信中的应用

随着现代通信技术发展越来越快,无线传输通信技术得到广泛应用。在工业应用领域无线传输技术的应用场景越来越多,如不同功耗速率传输的2G、3G、4G等广域网技术等。而低功耗低速率的广域网传输技术Lora侧基于扩频技术的超远距离无线传输方案,可提供无线通信技术运行于ISM频段(Industrial Scientific Medical Band),具有经济性好、组网方便、易于实现,并具有较好的抗干扰性等特点。它最大特点就是在同样的功耗条件下比其他无线方式传播的距离更远,实现了低功耗和远距离的统一,它在同样的功耗下比传统的无线射频通信距离扩大3-5倍,传输距离范围长达15至20公里。文章从无线传输技术应用需求为解决近距离可靠传输进行分析,结合两个站点间相距1公里内的无线通信存在的信号衰减、传输数据量和抗干扰能力等因素,提供了具有针对性的无线通信解决方案。

基于LoRa技术的无线通信应用研究

LoRa(Long Range)作为低功耗广域网技术(Low Power Wide Area Network,LPWAN)中的重要组成,将数字扩频、数字信号处理和前向纠错编码等多项技术相融合,拥有通信距离远、抗干扰能力强、功耗低等特性,可有效解决当前其他通信方式数据采集成功率不高、数据拥塞等缺点,因此在远距离低速通信场景中展现出独特的优越性。