Qchat PTT与350M模拟对讲调度互通的可行性分析

基于CDMA2000 1x EV-DO Rev.A的Qchat数字对讲与公安专网350M(800M)模拟对讲,利用QC350M(自命名)实现Qchat与350M对讲互通的探讨。文章首先介绍了基于CDMA2000 1x EV-DO Rev.A的手机对讲业务Qchat PTT的优势,在针对目前我国公安系统仍大量使用的调度系统(350M)的不足,并结合Qchat PTT已逐步渗透到公安系统的现状,提出Qchat PTT与350M PTT调度互通的可行性分析。     

基于GPS/GIS的出租车调度系统的设计与实现

文章基于GPS/GIS技术设计和实现了一种新型的出租车调度系统,该系统设计了一种出租车司机互助报告乘客位置的新型叫车模式,改进了传统的出租车叫车方式.本系统包含三大部分:调度终端、通信平台和调度平台.调度终端是基于三星S3C2440硬件平台和WINCE系统的智能嵌入式设备,实现与调度平台的通讯和现场智能控制;通信平台基...     

GoTa数字集群与PoC方式的PTT业务对比分析

本文通过分析现今集群业务和市场需求特点,着重对基于CDMA技术的GoTa集群系统和PoC方式的PTT业务在技术实现方式、业务功能、应用效果等方面进行了对比。     

PTT/POC技术综述

本文介绍了PTT(Push To Talk)/POC(PTT Over Cellular)业务的技术定位,标准和规范,对当前PTT/POC业务的核心技术进行了分析,包括体系结构,信令协议以及服务器和终端的实现方式.最后,介绍了当前PTT/POC尚待解决的技术问题.     

一种在3G系统中实现PTT业务的方法

文章介绍了几种已有的实现PTT业务的方法,在对比其优缺点后提出了一种在3G系统中以VoIP方式实现PTT业务的方案,并对该方案进行了详细的分析介绍。     

基于VxWorks的多任务程序设计及通信管理

为了满足系统各个任务对实时性的要求,需要实现各个任务的并行处理。针对VxWorks操作系统的多任务调度机制和任务通信方式进行了分析;采用基于时间片轮转调度实现多任务程序设计,可以动态改变各个任务期望运行的时间片;对各种通信方式和实现方法进行了比对,并给出了优化方案。上述设计方法实时性强,可靠性高,系统可扩展性良好,能够很好地满足工程需要。     

基于E&M信令分析VHF通信系统PTT的工作方式及传输

文章针对E&M信令进行了概述,分析了基于E&M信令分析VHF(甚高频)通信系统PTT的工作方式,并探析了Ⅴ类E&M信令下PTT信号的传输控制,希望能够为我国民航事业的长足、稳定发展做出应有的贡献。     

GPS/GPRS/GSM车辆监控管理系统的设计

通过对GPS车辆定位监控系统及相关技术的深入研究,设计实现了中心监控调度系统对GSM通信方式数据的接收、处理和通信。整个系统基于C/S(客户端/服务器)结构实现。     

移动互联网技术在电力调度系统中的应用

随着现代信息科学技术的进步,我国电网运营水平不断提升,传统电网调度信息传递方式存在效率低、时效性差等问题严重制约了大电网的发展。为此,充分利用移动通信设备的优势,本文提出了一种基于移动平台的电力调度系统。对智能移动平台的移动通信、平台管理以及安全控制等关键技术进行研究,构建电力调度移动系统的基本结构框架;基于系统基本架构及关键技术对电力调度移动系统的相关功能展开详细的介绍,并将其应用于电力调度的典型业务管理工作中。系统的应用结果表明：本文的研究成果能够为建设高效快捷的电力调度系统以及提升电网运行管理水平提供理论指导依据。     

基于FPGA的EPA通信调度设计与实现

通过分析EPA通信调度原理,提出一种采用硬件方式实现确定性通信调度的方法,避免了EPA通信调度算法受CPU中断和操作系统等因素的影响,并设计出基于FPGA的EPA通信调度系统。本文着重对EPA通信调度功能模块以及通信调度控制算法进行设计,形成了EPA通信调度算法的IP核。并编写testbanch测试文件,通过建立实验验证模型,对该IP核进行逻辑功能验证。测试结果证明了该系统能够实现EPA通信调度算法的调度功能。     

Multidimensional QoS cloud computing resource scheduling method based on stakeholder perspective

A multidimensional cloud computing architecture is designed and a multidimensional cloud resource scheduling model is constructed based on the stakeholder perspective of cloud users and cloud service providers to meet the high QoS requirements of cloud users (such as task execution time and task completion time) with low computing costs (such as energy consumption,economic costs and system availability).For the second-level cloud resource scheduling,an MQoS cloud resource scheduling algorithm based on multiple Greedy algorithm is proposed.The experimental results show that under the four cloud computing application scenarios with no aftereffects,the MQoS cloud resource scheduling algorithm has an overall increase of 206.42%~228.99% and 34.26%~56.93 in terms of multidimensional QoS degree compared with FIFO and M2EC algorithms.It has an average overall reduction of 0.48~0.49 and 0.20~0.27 in terms of cloud data center load balance difference.     

Scheduling for Concept-Oriented Rapid Prototyping

In this paper scheduling strategies for a rapid prototyping system are discussed. Our rapid prototyping system is able to deal with several CASE-tools and generate code for models of heterogenous domains. By using the emerging CASE Data Interchange Format CDIF the model data of CASE-tools is represented tool-independent. This tool-independent layer serves as a basis for analysis, simulation and code generation. The generated code is partitioned in tasks which must be scheduled as fast as possible using a real-time operating system to support high performance applications. We classify scheduling requirements for the constraints of rapid prototyping and present a new scheduling strategy called pseudo-rate scheduling which significantly improve the execution speed of rapid prototyping applications. Additionally, we provide a set of equations to estimate schedulability. Experimental results demonstrate the main advantages of our scheduling strategy.     

基于功率调度的在线建模自适应反馈控制系统的研究

自适应有源噪声控制是噪声控制中的一项先进技术。使用附加噪声建模的自适应控制系统会增加输出的残留噪声,而且还可能造成反馈控制系统发散。功率调度方法可以有效地减小残留噪声,增加系统的鲁棒性。根据是否使用功率调度方法,对2种在线次路径建模自适应反馈控制系统进行了研究,仿真结果表明采用功率调度方法的自适应反馈系统比不使用功率调度方法的反馈系统具有更好的降噪效果。     

基于SLNR准则的MU-MIMO下行链路的预编码与用户调度

在多用户MIMO（MU-MIMO）系统的下行链路中,为了降低用户端的处理复杂度,发射端预编码的设计对多用户MIMO系统的性能非常重要,基于信漏噪比（SLNR）准则的预编码技术由于同时考虑了共信道干扰（CCI）和噪声,提高了系统的性能,但基站同时服务的用户有限,基于信漏噪比最大的用户调度能够合理地选择用户,提高了多用户分级增益,使系统获得更高的系统容量和系统性能。仿真结果表明,基于SLNR准则的多用户预编码在系统容量和误码率方面要优于单一考虑CCI的迫零预编码（ZF）和单一考虑噪声的最大化每个用户接收到信号的信噪比预编码（MRT）。在采用SLNR预编码的条件下,信漏噪比最大的用户调度系统性比轮询调度和最大信道增益调度好,并且随着待选用户数的增多,不会给系统的调度策略带来很大的影响。     

云计算中基于能耗比例模型的虚拟机调度算法

针对资源虚拟化环境中的混合型负载调度问题,提出一种基于能耗比例模型的虚拟机调度算法.该算法利用处理器的"性能计数器"机制来评估各个虚拟机的近期能耗状态,并采用"最近最小能耗比例优先"的策略进行调度.理论分析给出了该算法的有效性证明和相关特性.实验结果显示,当系统面对混合型负载时,基于能耗比例模型的调度算法在"调度偏差"和"相对能效"两方面明显优于现有的虚拟机调度算法.     

Long-range science scheduling for the Hubble Space Telescope

Observations with NASA's Hubble Space Telescope (HST) are scheduled with the assistance of a long-range scheduling system (Spike) that was developed using artificial intelligence techniques. In earlier papers, we have described the system architecture and the constraint representation and propagation mechanisms. In this paper we describe the development of highlevel automated scheduling tools, including tools based on constraint satisfaction techniques and neural networks. The performance of these tools in scheduling HST observations is discussed.     

Service differentiation in multirate wireless networks with weighted round-robin scheduling and ARQ-based error control

The radio link-level delay statistics in a wireless network using adaptive modulation and coding (AMC), weighted round-robin (WRR) scheduling, and automatic repeat request-based error control is analyzed in this letter. WRR scheduling can be used for service differentiation similar to that achievable by using the generalized processor sharing scheduling discipline. The analytical framework presented in this letter captures physical and radio link-level aspects of a multirate multiuser wireless network (e.g., general fading model, AMC, scheduling, error control) in a unified way. It can be used for admission control and cross-layer design under statistical delay constraints. The analytical results are validated by simulations. Typical numerical results are presented, and their useful implications on the system performance are discussed.     

CDMA2000 1xEV-DO中的分组调度算法

移动通信系统需要更好地支持分组数据业务，并满足高速分组数据业务的服务质置要求。这可以通过采用好的调度算法提高平均业务速率和系统整体稳定性实现。针对CDMA2000 1x EV-DO系统的有代表性的调度算法有3种：正比公平算法、速率受限的最大载干比算法、加权公平排队-正比公平（WFQ-PF）联合算法。正比公平调度算法是一种算法简单实用的调度方案，但不能满足用户的服务质景保证；速率受限的最大载干比算法具有比正比公平算法更高的平均吞吐量，可方便地在吞吐量和公平性之间获得很好的折衷；WFQ-PF联合算法具有良好的综合性能，但算法较复杂。     

The Performance of Random and Optimal Scheduling in a Time-Multiplex Switch

In a time-multiplex switching system, the incoming traffic must be scheduled to avoid conflict at the switch output (two or more users converging simultaneously upon a single output). Two scheduling algorithms, random scheduling and optimal scheduling, are explored in this paper. Random scheduling is computationally simple, whereas optimal scheduling is currently very difficult. We have found, using a traffic model appropriate for circuit switched traffic that increases of typically 10 to 15 percent in offered load can be obtained through optimal scheduling (as compared to the much simpler random scheduling algorithm). The improvement is a function of the number of time slots (or circuits) per time-multiplexed frame, and falls to zero for both very small and very large frame sizes. Thus, in many circuit switching applications, providing a computationally expensive optimal schedule may not be warranted. This conclusion has important ramifications for both electronic and emerging photonic switching systems since it reduces the importance of the costly design feature of optimal scheduling.     

Rate scheduling in multiple antenna downlink wireless systems

We consider scheduling strategies for multiantenna and multibeam cellular wireless systems for high-speed packet data services on the downlink. We establish a fundamental connection between the stability region of the queuing system and the set of feasible transmission rates, which provides the basis for the scheduling algorithm proposed in this paper. Transmission using adaptive steerable beams and fixed sector beams are considered and average delay versus throughput results are obtained through simulations for the proposed scheduling scheme in each case. While in single antenna systems multiuser diversity gains are achieved by the scheduling algorithms that transmit to a single user in each scheduling interval, our results show that with multiple antennas, transmitting to a carefully chosen subset of users has superior performance. The multiantenna scheduling problem is closely related to the problem of coordinated scheduling for transmission through multiple base stations, where a user can receive signals from several base stations simultaneously. We consider the special case when three single-antenna base stations are allowed to cooperate and transmit to the users in the triangular region between the base stations and propose scheduling strategies that demonstrate significant gains.