基于SOPC的嵌入式网络化测控网关设计

为了实现测控设备的网络化远程访问控制,必须设计用于IEEE 488等测控接口总线协议与网络协议转换的网关设备,给出了一种基于SOPC技术的嵌入式网络化测控网关设计方法,其中借鉴了基于组件的模块化设计思想,采用固件分层设计和多语言混合编程模式,能够融合多种测控协议,将LAN、GPIB、USB、RS232等接口集成到了一个系统上,实现了嵌入式web服务器功能,客户端能够基于IE等浏览器实现测控设备的远程访问控制;最后给出了系统综合验证方法,结论表明:系统功能完善,符合网络化、模块化、通用化和智能化的发展方向。     

基于LabVIEW的USB设备无线测试系统设计

针对传统有线USB设备测试系统存在布线、单目标、通用性差等缺陷,设计一套基于LabVIEW的USB设备无线测试系统;系统以LabVIEW为软件开发平台,进行虚拟仪器前面板设计与后台程序的编写;利用无线数据收发模块及其余硬件设备,搭建上位机与设备间无线数据通讯的桥梁;以宏晶STC12C5A60S2单片机为核心控制器,通过引入USB总线接口芯片CH375扩展了USBHOST功能,从而实现上位机和USB设备间数据的无线采集与传输;本系统主要应用于对USB设备的开发调试和测试过程。     

嵌入式LCD情报板网关系统设计与开发

针对LED情报板显示规模小、控制难、信息无法实时发布的问题,进行了显示方式、控制方法和通信模式的分析,提出了一种嵌入式LCD情报板网关系统的设计方案。该系统由智能显示模组、网关、后台数据库和WEB界面四部分组成,智能显示模组包括LCD显示屏、触摸屏、S3C2440嵌入式微处理器、人机界面处理系统和RS232通讯接口;网关是以嵌入式Linux操作系统OpenWrt和嵌入式微处理器RT5350为平台,实现了802.11b/g/n高速无线局域网、以太网WAN和RS232串口通信相互转换的功能;后台数据库是以html和php语言为软件支撑,管理员可以通过WEB界面灵活的管理情报板内容和配置网关参数。在校园搭建情报板网关系统并进行测试,结果表明,该系统能够将底层服务与上层管理紧密结合,扩大信息覆盖面,提高信息利用率和发布效率,在信息发布技术的发展上有一定的参考、推广价值。     

透明ONU和附加广播功能的无源光网络平滑升级

提出了一种经济有效的无源光网络平滑升级方案。广播信号采用PolSK直接调制在ASK调制的下行单播信号上,上行信号通过再调制方式调制到下行光载波上实现透明ONU;升级PON的下行单播信号采用曼彻斯特编码来抑制其他低频分量,可以减少其对共存的广播信号和上行信号的干扰;仿真和实验证明,所有信号在25km内实现极低误码传输(BER≤10~(-9))。方案可以实现升级PON与现存PON的共存,同时实现了透明ONU和附加广播功能,实现了高带宽利用率并降低了运营维护成本。     

一种基于Zigbee与GPS山体滑坡监测系统开发

针对山体滑坡监测布线难度大,实施困难问题,提出了一种基于无线传感器网络的山体滑坡监测设计方案;该方案结合无线网络传感器技术,GPRS技术以及GPS定位技术,通过无线传感器网络采集山体倾角,液位值实时数据,以及GPS节点坐标信息汇总到嵌入式网关通过GPRS网络接入远程监控中心;通过综合分析可以及时预测滑坡发生的具体位置,为及时疏散居民提供宝贵的时间;文章详细介绍了系统的软硬件设计方法,系统通过实物搭建和实验分析验证了方案可行性;测试表明:系统稳定性好,相对误差控制在3%以内,可以较好地预测滑坡发生。     

基于ZigBee的矿井环境监测系统设计

针对矿井环境恶劣、干扰严重和传统信号有线传输的现状,设计了基于ZigBee无线传感器网络的矿井环境监测系统;系统由井下ZigBee传感器终端节点、路由器、协调器和井上监测上位机构成,其中传感器终端节点对井下瓦斯、一氧化碳、温度等信号进行采集,利用ZigBee无线组网技术将信号送给井上PC机,井上管理人员通过PC机能够随时掌握井下设备和环境的状况;与传统的信号有线传输监测方法相比,该系统低功耗、低成本、抗干扰;实验结果表明,该系统运行稳定可靠,精度高,具有一定的实用性和推广价值。     

一种自适应无线传感器网络监控系统网关设计

针对无线传感器网络网关通信方式单一、灵活性差的问题,设计并实现了一种自适应WSN监控系统网关,网关能够根据工作环境选择以太网、WiFi、GPRS通信方式中的一种来转发无线传感器网络的数据;基于STM32F107微处理器完成了网关的硬件开发和软件设计,实现了数据汇集、通信方式的选择、远程通信等功能;基于VC++完成了监控中心软件的开发,实现了数据接收、图形化显示、存储、查询等功能;搭建校园温湿度监控系统对网关性能进行测试,测试结果表明,该网关有扩展灵活、可靠性高、使用方便等特点。     

多通道分布式环境监测系统的超高频RFID网关设计

传统的超高频RFID网关无法避免由于多种数据同时在一个网关进程中竞争,将会造成网关的冲突任务失败,从而降低了环境监控信息采集的准确率。为此,设计并实现了基于MC13213的多通道分布式环境监测系统的超高频RFID网关系统。硬件部分详细阐述了基于MC13213的RFID网关设计方法,重点阐述网关终端节点、网关路由节点和网关中心节点的设计方法。软件部分详细阐述了网关进程之间通信机制的设计和网关任务机制数据结构程序设计方法。实验结果表明,利用本文系统能够避免超频率RFID网关在通信过程中的冲突,提高了环境信息采集的准确率。     

基于S12X系列双核单片机的CAN网关设计

集成XGATE协处理器内核的S12XE系列双核单片机具有处理速度快、反应时间短、功耗低等优点,在嵌入式应用中具有独特优势和很好的应用前景。本文采用16位双核单片机MC9S12XEQ512作为主控制器,以集成信号和电源隔离功能的CAN收发器芯片ADM3053来实现CAN接口电路,设计并实现了一个可以连接3个CAN通信子网的CAN网关,有效实现了系统的小型化、低功耗、低成本。采用双核处理技术来优化CAN网关的处理流程,由协处理器XGATE来处理各种中断,S12X主CPU则专注于协议处理和消息转发。实际应用表明,系统运行稳定可靠,与传统的采用单处理器实现的CAN网关相比,系统的数据吞吐能力和实时性得到了明显改善。     

通用实物设备接入技术研究与实现

综合试验验证技术正朝着“虚实融合”的方向发展,将实物试验设备接入虚拟试验的支撑平台进行统一试验,成为综合试验验证的一大关键技术。本文提出一种通用的实物设备接入技术,一方面通过用户界面配置,自动生成与实物设备传输协议相匹配的接入网关,解决传输协议异构性问题;另一方面,通过采用嵌入式的硬件协议转换器,实现高效率的实时设备接入。实验证明,协议转换耗时为百微秒级,为实现“虚实融合”的综合试验验证奠定了基础。     

Analysis of physical layer performance of hybrid optical-wireless access network

The hybrid optical-wireless access network (HOWAN) is a favorable architecture for next generation access network. It is an optimal combination of an optical backhaul and a wireless front-end for an efficient access network. In this paper, the HOWAN architecture is designed based on a wavelengths division multiplexing/time division multiplexing passive optical network (WDM/TDM PON) at the optical backhaul and a wireless fidelity (WiFi) technology at the wireless front-end. The HOWAN is proposed that can provide blanket coverage of broadband and flexible connection for end-users. Most of the existing works, based on performance evaluation are concerned on network layer aspects. This paper reports physical layer performance in terms of the bit error rate (BER), eye diagram, and signal-to-noise ratio (SNR) of the communication system. It accommodates 8 wavelength channels with 32 optical network unit/wireless access points (ONU/APs). It is demonstrated that downstream and upstream of 2 Gb/s can be achieved by optical backhaul for each wavelength channel along optical fiber length of 20 km and a data rate of 54 Mb/s per ONU/AP along a 50 m outdoor wireless link.     

The Design of Passive Optical Networking+Ethernet over Coaxial Cable Access Networking and Video-on-Demand Services Carrying

Abstract

Video on demand is a very attractive service used for entertainment, education, and other purposes. The design of passive optical networking+Ethernet over coaxial cable accessing and a home gateway system is proposed. The network integrates the passive optical networking and Ethernet over coaxial cable to provide high dedicated bandwidth for the metropolitan video-on-demand services. Using digital video broadcasting, IP television protocol, unicasting, and broadcasting mechanisms maximizes the system throughput. The home gateway finishes radio frequency signal receiving and provides three kinds of interfaces for high-definition video, voice, and data, which achieves triple-play and wire/wireless access synchronously.     

The WDM–ROF–PON based on linearly-polarization dual-wavelength fiber laser and CSRZ–DPSK modulation

In this paper, we design a linearly-polarized dual-wavelength fiber laser used in WDM–ROF–PON, which can achieve wire-line and wireless access synchronously. With polarization multiplexing, the dual-wavelength fiber laser is the union light source of WDM–PON. With the CSRZ–DPSK modulation, the wireless access system of ONU can save RF source and the frequency of radio carrier can be controlled by OLT. The networking has the credible transmission property, including fiber transmission and wireless access.     

Fiber-wireless (FiWi) access network: Performance evaluation and scalability analysis of the physical layer

The fiber-wireless (FiWi) access network is a prestigious architecture for next generation (NG) access network. NG access networks are proposed to provide high data rate, broadband multiple services, scalable bandwidth, and flexible communication for manifold wireless end-users (WEUs). In this paper, the FiWi access network is designed based on a wavelengths division multiplexing/time division multiplexing passive optical network (WDM/TDM PON) at the optical backhaul with data rate of 2.5 Gb/s and wireless fidelity-worldwide interoperability for microwave access (WiFi–WiMAX) technologies at the wireless front-end along a 50 m–5 km wireless links with data rate of 54–30 Mb/s, respectively. The performance of the optical backhaul and the wireless front-end, in the proposed FiWi access network, has been evaluated in terms of bit error rate (BER), error vector magnitude (EVM), and signal-to-noise ratio (SNR) of the physical (PHY) layer. The scalability of the optical backhaul based on maximum split ratio of 1/32 for each wavelength channel and a fiber length of 24 km from the central office (CO) to the access point (AP) is analyzed with bit error rate (BER) of 10⁻⁹.     

Ring-based PON supporting multiple optical private networks using OCDMA technique

This work is a novel attempt to provide local communications for multiple optical private networks (PNs) within ring-based passive optical network (PON). In order to improve network throughput performance, PNs traffic is decentralized from PON traffic let no extra traffic management into optical line terminal (OLT). To achieve multiple secure optical private networking over ring-based PON layout, optical code division multiple access (OCDMA) technique is applied. This technique leads to interconnect optical network units (ONUs) in the same PN sharing the same codeword while other PNs benefiting from different codewords. This scheme can be used in access networks to establish discrete communications between different sites in an enterprise or a university campus or even a residential accommodation. The proposed network architecture is then set up and its bit error rate performance is experimentally demonstrated. Finally, the network scalability and throughput performance of the proposed scheme are analyzed.     

基于ZigBee与WiFi的无线智能照明系统设计

为了提高照明系统的使用效率,减少电能的浪费。设计了一种以TI公司的CC2530芯片与Ralink公司RT5350芯片为核心的,结合了ZigBee与WiFi技术的无线智能照明系统。该系统在控制终端与各照明节点之间构建混合型无线通信网络,并实现了将ZigBee网络与UPnP标准相结合。控制终端可实时监测各照明节点的状态,同时可发送控制命令到各终端节点。分析了系统的工作原理、硬件架构、软件设计。实验结果表明,该系统能够可靠的完成信息的采集与发送,误包率在50m 范围内可控制在4.0%以内,系统具有误包率低,稳定可靠,成本低等优点,实现了照明系统的网络化管理。     

Novel Quantum Virtual Private Network Scheme for PON via Quantum Secure Direct Communication

Two quantum secure direct communication (QSDC) protocols with quantum identification (QI) based on passive optical network (PON) architecture are proposed. One QSDC protocol can be implemented between two different optical network units just with simple configurations of PON by optical line terminal when they are in the same virtual private network after optical line terminal performing QI to the optical network units in the given PON architecture. The other QSDC protocol is also implemented between any two legitimated users in the virtual private network but with considerable reduction of workload of the optical line terminal. The security analysis shows that the proposed QSDC schemes with quantum identification are unconditionally secure and allow the legitimate users to exchange their secret information efficiently and to realize a quantum virtual private network in the PON networks ultimately.     

Alternative Wired and 60-GHz Wireless Full Duplex Access Based on a Polarization Orthogonal Dual-Tone Optical Millimeter-Wave Signal

Abstract

A novel full duplex fiber wireless link providing alternative wired and 60-GHz wireless access is proposed based on a polarization orthogonal dual-tone optical millimeter-wave signal. In a hybrid optical network unit, the downlink optical signal can be decomposed as a single-sideband optical millimeter-wave signal (baseband optical signal) for wireless (wired) access by a polarization controller and polarization beam splitter. The uplink optical carrier abstracted from the downlink optical signal makes the hybrid optical network unit free from the optical source. The simulation results show that both downlinks and uplinks for either wired or wireless access can maintain quite good performance over 60 km of fiber.