无线病房呼叫系统的设计

介绍利用单片机的串行全双工通信和高频发射接收电路设计的多路无线医院病房呼叫系统,该系统具有床号、呼叫次数显示、翻查、回复等功能,用于医院病房对护理总台的呼叫,省略了复杂的布线,操作简单,使用方便.     

具有记忆功能的病房呼叫系统

介绍一种利用８０３１单片机实现的病房呼叫装置。该机除具备普遍呼叫仪的主要功能外，还能记忆１０天内各次呼叫的病号、呼叫时间、护士响应时间等多项数据，并可随时进行打印、集服务，管理和记录等多种功能于一身。     

一种面向未来的医用监控系统

以医院病房呼叫系统为基础,介绍了一套基于P89LPC932单片机控制的医用监控系统.该系统利用单片机和无线通信技术很好地实现了一对多的数据传输,克服了以往有线方案连线繁琐、安装复杂、功能简单等缺点.给出了相关的硬件和软件实现技术.     

病房无线呼叫监护系统的设计

病房无线呼叫监护系统，对每一病床设置不同的地址编码进行无线呼叫，译码器的地址电平由单片机扫描识别。终端监护台对相应的病床号进行数字显示并作出语音提示，文章介绍了该系统硬件配置及软件设计。     

基于ZigBee技术的无线医院病房呼叫系统设计

本文基于ZigBee技术设计医院病房呼叫系统,通过无线方式实现病人向护士发出呼叫请求消息的功能,取代传统病房呼叫系统的有线模式.本系统设计具备让病人实时呼叫的功能,在护士信息接收站的Web监控终端,管理者能实时查看病人的呼叫信息,护士在安卓客户端和手持终端也都能实时收到病人的呼叫请求.测试结果表明,整个系统运行正常,病人发出的呼叫信息能及时发送到护士手持终端和护士信息接收站,抗干扰能力强,硬件设计稳定、可靠,软件界面友好,实现了无线病房呼叫系统的应用要求.     

基于单片机的病房呼叫系统设计

利用单片机设计了病房呼叫系统,分析了硬件电路与软件设计。该系统采用电源载波技术,利用系统的两芯电源线,实现语音信号和呼叫信号的交换。系统主机由MC88051单片机实现,呼叫分机选用PIC12C508单片机,显示主控芯片选择51类的AT89C2051单片机,通信方式采用串行异步半双工通信方式。系统具有可靠性高、成本低、功能强大、安装方便等优点,具有较强的实用价值。     

一种低成本的病床呼叫系统

基于STC89C52单片机设计了一款低成本病床呼叫系统。使用单片机控制语音合成芯片和液晶显示模块,通过ISD1760的FT直通操作模式录制语音信息,然后利用ISD1760的SPI模式接口与单片机的I/O端口连接通信,实现单片机对语音芯片的控制。同时加入留言功能,使呼叫系统更加人性化。样机测试表明,呼叫系统的稳定性高,解决了落后地区乡镇医院中病人得到及时护理的问题。     

无线病床呼叫系统设计

文章设计了一种基于STC89C51单片机的病房呼叫系统,整个系统以STC89C51单片机为核心辅以无线模块以及显示电路,能够实现病人和医护人员之间的信息传递。当有按键按下时,无线发射模块编码并发射信号,再由无线接收模块接收到信号译码后汇总到单片机,最终由LCD1602示出呼叫者的病床号并伴有蜂鸣器的报警声,从而获得医疗救治。     

基于SC1128的病房呼叫系统

本文首先阐述了基于SC1128的病房呼叫系统的基本组成以及一些相关的硬件设计和软件设计。然后,基于单片机多机通讯的基本概念,以SC1128扩频通信芯片为基础,辅以外围电路,设计了一个利用低压电力线传输数据的病房呼叫系统。该系统具有较广泛的实用意义,可应用于医院和远程医疗。     

基于MCS-51单片机的无线病房呼叫系统设计

本文介绍了基于系统MCS-51系列单片机核心,利用高频无线发射接收电路,数码管,蜂鸣器等组建和实现的无线病房呼叫系统。论文主要介绍了单片机的具体应用,连接和控制等问题。在此基础上给出了详细的电路设计和说明。     

Managing run-time interactions between call-processing features[intelligent networks]

Network service providers continue to require new and different call processing features for their switching systems. Open call processing addresses the limitations of the current feature procurement process by being vendor-independent; i.e. the same call processing model is used for all switching systems and it is required that features be independently installable on a running system. A structure for call processing software that supports open call processing is described. Different approaches to managing call processing features are discussed. The implementation of a simulation model of a feature manager that ties 17 interacting features together into a single feature package is presented     

A new call control scheme of Push-To-Talk system

For Push-To-Talk (PTT) system based on Public Mobile Data Network (PMDN), the end-to-end time delay is the key aspect of the user’s experience. The Push-Over-Cellular (POC) scheme defined by Open Mobile Alliance (OMA) is based on the VoIP phone model and use SIP protocol as the call control scheme. The call setup time delay in SIP may reach to several seconds, which is unacceptable for the PTT service. In this paper, we provide a new call control scheme for PTT system based on PLMN network. By combining the apriority knowledge of PTT call model and the priority control scheme, we encapsulate the signaling message and the voice data into a same data packet, when the user push the button, the voice and the call control signaling are sent to the server at the same time. So the long time delay of call setup procedure of POC scheme can be eliminate. The end-to-end call delay can be decreased significantly. The experiment result based on the commercial CDMA2000 1X network of China Unicom shows that the call delay can be decreased to 600 ms, which approach to the traditional trunk communication system’s requirement.     

Probability models of microcell coverage

Once a subscriber unit served by a microcell initiates a call, it must remain in the coverage area of the microcell long enough to complete call set up and hand-off functions. This restricts the minimum size attainable by a microcell. This paper derives the relationship between the microcell size, the call processing time, and the probability that a subscriber unit, initiating a call, will remain inside the microcell coverage area for at least the duration of call processing. Under simple assumptions, time spent in the coverage area of the microcellbefore andafter call initiation have the same cumulative density function, which is derived in this paper for traffic conditions encountered in highway and metropolitan settings.This paper is based on a contribution to the ETSI GSM2 Standards, Ronneby, Sweden, September 1991 [1].     

基于PLC病床紧急呼叫系统的设计

为丰富病床呼叫系统的控制方式,在满足病房与护士站实时通信时,能够方便地了解各病房的情况,实现医院对病房科学化管理。本文采用PLC可编程控制器实现紧急呼叫系统的设计,该系统设计结构简单,易于管理,可及时、准确的实现病房呼叫管理。     

基于FPGA的多路并行PCM数据收发模块的设计

在自动测试系统中,为了实现多路并行PCM数据的同时接收与处理,设计了一种以FPGA为主控制核心的并行数据收发模块,该模块实现了隔离RS422接口电路设计,双通道并行PCM数据的接收,隔离分档电压输出等。并行数据收发的逻辑设计,采用乒乓操作的思想轮流通过单通道回传给上位机,由软件对数据进行分包检验处理。经过多次的实际测试验证每路PCM数据的传输速率可达1MB/s,在保证合理性以及可靠性的前提下,相对于单通道数据的传输在速率上有了大幅提高。     

Traffic management in a multicode CDMA system supporting softhandoffs

A traffic management scheme is proposed in a multicode code-division multiple-access system supporting soft handoff that uses guard channels and a queue for real-time traffic. Preemptive queue control gives priority to queued handoff calls. Handoff traffic is derived as a function of the new call arrival rate, the size of the soft handoff region, mobile speed, the new call blocking probability, and the handoff failure probability. System performance with K types of calls is analyzed by introducing a concept of effective channel. The effects of the number of guard channels, the number of effective channels, system capacity, and other factors are numerically investigated. The effectiveness of the proposed queue control scheme is also observed in terms of handoff processing delay     

基于GSM网络的电梯五方通话技术研究

针对现有电梯通话系统布线麻烦,组装困难和维护成本高等缺点,以及对于停电时无法呼叫等不足,设计并实现了一种基于GSM无线通信的应急呼叫系统.该系统主要是用于在电梯出现故障、人员被困于电梯中时进行应急呼叫用的.它是用单片机STC 11 F05E作为核心处理和控制单元,通过I/O口来检测是否有呼救信号,通过串口发送AT命令给GSM无线通信模块(SIM900A)来实现无线应急呼叫;通过对SIM卡的设置可以进行对专用号码进行有优先级的有序呼救,确保一定有人能够接听到这个应急电话;通过I/O口实现对语音电路的控制,实时地接通和断开语音通路.系统采用UPS不间断电源来供电的,轿厢、机房、轿顶(井道顶)、底坑这四方都是采用馈电的方式来对分机进行供电;所以即使在停电状态下也可以进行呼救.实际与实验表明,这种通话呼救系统安装简单(不需要布线),无线通话稳定可靠(利用了现有的GSM基站),成本低,具有较高的应用价值和广阔的市场前景.     

On-call processing delay in high speed networks

In future BISDN networks, significant burdens will be placed on the processing elements in the network since call routing and admission policies will be more computationally intensive than those in present day networks. Thus, the bottleneck in future networks is likely to shift from the communication links to the processing elements. The delays at these elements are influenced by their processing capacity and factors such as; routing algorithms, propagation delays, admission control functions, and network topology. The goal of this paper is to characterize the behavior of these factors on the call setup time and accepted call throughput. This behavior is examined for three sequential routing schemes and two flooding routing schemes under various network parameters and different forms of admission control. The results of our study indicate that processing capacity and the admission control function can affect the call setup time and accepted call throughput significantly while propagation delay does not affect these performance measures significantly     

基于公用电话网的时间认证系统研究与实现

介绍了一种利用公用电话网传输时间信息的系统。他采用单片机控制，具有定时拨号、自动接听的功能，可以在没有人员参与的情况下完成授时过程。     

用于多个引伸计数据采集的接口电路设计

针对力学实验或生产加工的实际功能需求,以高性能单片机STC12C5410AD为核心设计开发了一套用于多个电子引伸计数据采集的电路系统。系统硬件电路以24位高精度A/D转换芯片AD7714为模数转换器件,并且运用其放大模块进行信号的放大处理;下位单片机程序采用Keil C51进行编写,系统上位机软件应用VB进行设计和开发。全套系统造价低、体积小、便携性好,能同时检测和显示1～3路形变信号,测试实验表明该系统检测精度高、实时性好,能满足力学性能实验和生产加工现场的实际功能需求,具有较大的应用价值。