通信工程英语专业论文

On the deployment of VoIP in Ethernet networks:

methodology and case study

Khaled Salah, Department of Information and Computer Science, King Fahd University of Petroleum and Minerals, P.O. Box 5066, Dhahran 31261, Saudi Arabia Received 25 May 2004; revised 3 June 2005; accepted 3 June 2005. Available online 1 July 2005.

Abstract

Deploying IP telephony or voice over IP (V oIP) is a major and challenging task for data network researchers and designers. This paper outlines guidelines and a step-by-step methodology on how V oIP can be deployed successfully. The methodology can be used to assess the support and readiness of an existing network. Prior to the purchase and deployment of V oIP equipment, the methodology predicts the number of V oIP calls that can be sustained by an existing network while satisfying QoS requirements of all network services and leaving adequate capacity for future growth. As a case study, we apply the methodology steps on a typical network of a small enterprise. We utilize both analysis and simulation to investigate throughput and delay bounds. Our analysis is based on queuing theory, and OPNET is used for simulation. Results obtained from analysis and simulation are in line and give a close match. In addition, the paper discusses many design and engineering issues. These issues include characteristics of V oIP traffic and QoS requirements, V oIP flow and call distribution, defining future growth capacity, and measurement and impact of background traffic.

Keywords: Network Design，Network Management，V oIP，Performance Evaluation，

Analysis，Simulation，OPNET

1 Introduction

These days a massive deployment of V oIP is taking place over data networks. Most of these networks are Ethernet based and running IP protocol. Many network managers are finding it very attractive and cost effective to merge and unify voice and data networks into one. It is easier to run, manage, and maintain. However, one has to keep in mind that IP networks are best-effort networks that were designed for non-real time applications. On the other hand, V oIP requires timely packet delivery with low latency, jitter, packet loss, and sufficient bandwidth. To achieve this goal, an efficient deployment of V oIP must ensure these real-time traffic requirements can be guaranteed over new or existing IP networks. When deploying a new network service such as V oIP over existing network, many network architects, managers, planners, designers, and engineers are faced with common strategic, and sometimes challenging, questions. What are the QoS requirements for V oIP? How will the new V oIP load impact the QoS for currently running network services and applications? Will my existing network support V oIP and satisfy the standardized QoS requirements? If so, how many V oIP calls can the network support before upgrading prematurely any part of the existing network hardware? These challenging questions have led to the development of some commercial tools for testing the performance of multimedia applications in data networks. A list of the available commercial tools that support V oIP is listed in [1,2]. For the most part, these tools use two common approaches in assessing the deployment of V oIP into the existing network. One approach is based on first performing network measurements and then predicting the network readiness for supporting V oIP. The prediction of the network readiness is based on assessing the health of network elements. The second approach is based on injecting real V oIP traffic into existing network and measuring the resulting delay, jitter, and loss. Other than the cost associated with the commercial tools, none of the commercial tools offer a comprehensive approach for successful V oIP deployment. I n particular, none gives any prediction for the total number of calls that can be supported by the network taking into account important design and engineering factors. These factors include V oIP flow and call distribution, future growth capacity, performance thresholds, impact of V oIP on existing network services and applications, and impact background

traffic on V oIP. This paper attempts to address those important factors and layout a comprehensive methodology for a successful deployment of any multimedia application such as V oIP and video conferencing. However, the paper focuses on V oIP as the new service of interest to be deployed. The paper also contains many useful engineering and design guidelines, and discusses many practical issues pertaining to the deployment of V oIP. These issues include characteristics of V oIP traffic and QoS requirements, V oIP flow and call distribution, defining future growth capacity, and measurement and impact of background traffic. As a case study, we illustrate how our approach and guidelines can be applied to a typical network of a small enterprise. The rest of the paper is organized as follows. Section 2 presents a typical network topology of a small enterprise to be used as a case study for deploying V oIP. Section 3 outlines practical eight-step methodology to deploy successfully V oIP in data networks. Each step is described in considerable detail. Section 4 describes important design and engineering decisions to be made based on the analytic and simulation studies. Section 5 concludes the study and identifies future work.

2 Existing network

Fig. 1 illustrates a typical network topology for a small enterprise residing in a

high-rise building. The network shown is realistic and used as a case study only; however, our work presented in this paper can be adopted easily for larger and general networks by following the same principles, guidelines, and concepts laid out in this paper. The network is Ethernet-based and has two Layer-2 Ethernet switches connected by a router. The router is Cisco 2621, and the switches are 3Com Superstack 3300. Switch 1 connects Floors 1 and 2 and two servers; while Switch 2 connects Floor 3 and four servers. Each floor LAN is basically a shared Ethernet connecting employee PCs with workgroup and printer servers. The network makes use of VLANs in order to isolate broadcast and multicast traffic. A total of five LANs exist. All VLANs are port based. Switch 1 is configured such that it has three VLANs. VLAN1 includes the database and file servers. VLAN2 includes Floor 1. VLAN3 includes Floor2. On the other hand, Switch 2 is configured to have two VLANs. VLAN4 includes the servers for E-mail, HTTP, Web and cache proxy, and firewall. VLAN5 includes Floor 3. All the links are switched Ethernet 100 Mbps full duplex except for the links for Floors 1–3 which are shared Ethernet 100 Mbps half duplex.

3 Step-by-step methodology

Fig. 2 shows a flowchart of a methodology of eight steps for a successful V oIP deployment. The first four steps are independent and can be performed in parallel. Before embarking on the analysis and simulation study, in Steps 6 and 7, Step 5 must be carried out which requires any early and necessary redimensioning or modifications to the existing network. As shown, both Steps 6 and 7 can be done in parallel. The final step is pilot deployment.

3.1. VoIP traffic characteristics, requirements, and assumptions

For introducing a new network service such as V oIP, one has to characterize first the nature of its traffic, QoS requirements, and any additional components or devices. For simplicity, we assume a point-to-point conversation for all V oIP calls with no call conferencing. For deploying V oIP, a gatekeeper or Call Manager node has to be added to the network [3,4,5]. The gatekeeper node handles signaling for establishing, terminating, and authorizing connections of all V oIP calls. Also a V oIP gateway is required to handle external calls. A V oIP gateway is responsible for converting V oIP calls to/from the Public Switched Telephone Network (PSTN). As an engineering and design issue, the placement of these nodes in the network becomes crucial. We will tackle this issue in design step 5. Other hardware requirements include a V oIP client terminal, which can be a separate V oIP device, i.e. IP phones, or a typical PC or workstation that is V oIP-enabled. A V oIP-enabled workstation runs V oIP software such as IP Soft Phones .

Fig. 3 identifies the end-to-end V oIP components from sender to receiver [9]. The first component is the encoder which periodically samples the original voice signal and assigns a fixed number of bits to each sample, creating a constant bit rate stream. The traditional sample-based encoder G.711 uses Pulse Code Modulation

(PCM) to generate 8-bit samples every 0.125 ms, leading to a data rate of 64 kbps . The packetizer follows the encoder and encapsulates a certain number of speech samples into packets and adds the RTP, UDP, IP, and Ethernet headers. The voice packets travel through the data network. An important component at the receiving end, is the playback buffer whose purpose is to absorb variations or jitter in delay and provide a smooth playout. Then packets are delivered to the depacketizer and eventually to the decoder which reconstructs the original voice signal. We will follow the widely adopted recommendations of H.323, G.711, and G.714 standards for V oIP QoS requirements.

Table 1 compares some commonly used ITU-T standard codecs and the amount of one-way delay that they impose. To account for upper limits and to meet desirable quality requirement according to ITU recommendation P.800, we will adopt G.711u codec standards for the required delay and bandwidth. G.711u yields around 4.4 MOS rating. MOS, Mean Opinion Score, is a commonly used V oIP performance metric given in a scale of 1–5, with 5 is the best. However, with little compromise to quality, it is possible to implement different ITU-T codecs that yield much less required bandwidth per call and relatively a bit higher, but acceptable, end-to-end delay. This can be accomplished by applying compression, silence suppression, packet loss concealment, queue management techniques, and encapsulating more than one voice packet into a single Ethernet frame.

3.1.1. End-to-end delay for a single voice packet

Fig. 3 illustrates the sources of delay for a typical voice packet. The end-to-end delay is sometimes referred to by M2E or Mouth-to-Ear delay. G.714 imposes a maximum total one-way packet delay of 150 ms end-to-end for V oIP applications . In [22], a delay of up to 200 ms was considered to be acceptable. We can break this delay down into at least three different contributing components, which are as follows (i) encoding, compression, and packetization delay at the sender (ii) propagation, transmission and queuing delay in the network and (iii) buffering, decompression, depacketization, decoding, and playback delay at the receiver.

3.1.2. Bandwidth for a single call

The required bandwidth for a single call, one direction, is 64 kbps. G.711 codec samples 20 ms of voice per packet. Therefore, 50 such packets need to be transmitted per second. Each packet contains 160 voice samples in order to give 8000 samples per second. Each packet is sent in one Ethernet frame. With every packet of size 160 bytes, headers of additional protocol layers are added. These headers include RTP+UDP+IP+Ethernet with preamble of sizes 12+8+20+26, respectively. Therefore, a total of 226 bytes, or 1808 bits, needs to be transmitted 50 times per second, or 90.4 kbps, in one direction. For both directions, the required bandwidth for a single call is 100 pps or 180.8 kbps assuming a symmetric flow.

3.1.3. Other assumptions

Throughout our analysis and work, we assume voice calls are symmetric and no voice conferencing is implemented. We also ignore the signaling traffic generated by the gatekeeper. We base our analysis and design on the worst-case scenario for V oIP call traffic. The signaling traffic involving the gatekeeper is mostly generated prior to the establishment of the voice call and when the call is finished. This traffic is relatively small compared to the actual voice call traffic. In general, the gatekeeper generates no or very limited signaling traffic throughout the duration of the V oIP call for an already established on-going call. In this paper, we will implement no QoS mechanisms that can enhance the quality of packet delivery in IP networks. A myriad

of QoS standards are available and can be enabled for network elements. QoS standards may include IEEE 802.1p/Q, the IETF’s RSVP, and DiffServ. Analysis of implementation cost, complexity, management, and benefit must be weighed carefully before adopting such QoS standards. These standards can be recommended when the cost for upgrading some network elements is high and the network resources are scarce and heavily loaded.

3.2. VoIP traffic flow and call distribution

Knowing the current telephone call usage or volume of the enterprise is an important step for a successful V oIP deployment. Before embarking on further analysis or planning phases for a V oIP deployment, collecting statistics about of the present call volume and profiles is essential. Sources of such information are organization’s PBX, telephone records and bills. Key characteristics of existing calls can include the number of calls, number of concurrent calls, time, duration, etc. It is important to determine the locations of the call endpoints, i.e. the sources and destinations, as well as their corresponding path or flow. This will aid in identifying the call distribution and the calls made internally or externally. Call distribution must include percentage of calls within and outside of a floor, building, department, or organization. As a good capacity planning measure, it is recommended to base the V oIP call distribution on the busy hour traffic of phone calls for the busiest day of a week or a month. This will ensure support of the calls at all times with high QoS for all V oIP calls. When such current statistics are combined with the projected extra calls, we can predict the worst-case V oIP traffic load to be introduced to the existing network.

Fig. 4 describes the call distribution for the enterprise under study based on the worst busy hour and the projected future growth of V oIP calls. In the figure, the call distribution is described as a probability tree. It is also possible to describe it as a probability matrix. Some important observations can be made about the voice traffic flow for inter-floor and external calls. For all these type of calls, the voice traffic has to be always routed through the router. This is so because Switchs 1 and 2 are layer 2 switches with VLANs configuration. One can observe that the traffic flow for inter-floor calls between Floors 1 and 2 imposes twice the load on Switch 1, as the traffic has to pass through the switch to the router and back to the switch again. Similarly, Switch 2 experiences twice the load for external calls from/to Floor 3.

3.3. Define performance thresholds and growth capacity

In this step, we define the network performance thresholds or operational points for a number of important key network elements. These thresholds are to be considered when deploying the new service. The benefit is twofold. First, the requirements of the new service to be deployed are satisfied. Second, adding the new service leaves the network healthy and susceptible to future growth. Two important performance criteria are to be taken into account. First is the maximum tolerable end-to-end delay; and second is the utilization bounds or thresholds of network

resources. The maximum tolerable end-to-end delay is determined by the most sensitive application to run on the network. In our case, it is 150 ms end-to-end for V oIP. It is imperative to note that if the network has certain delay sensitive applications, the delay for these applications should be monitored, when introducing V oIP traffic, such that they do not exceed their required maximum values. As for the utilization bounds for network resources, such bounds or thresholds are determined by factors such as current utilization, future plans, and foreseen growth of the network. Proper resource and capacity planning is crucial. Savvy network engineers must deploy new services with scalability in mind, and ascertain that the network will yield acceptable performance under heavy and peak loads, with no packet loss. V oIP requires almost no packet loss. In literature, 0.1–5% packet loss was generally asserted. However, in [24] the required V oIP packet loss was conservatively suggested 5

to be less than 10. A more practical packet loss, based on experimentation, of below 1% was required in [22]. Hence, it is extremely important not to utilize fully the network resources. As rule-of-thumb guideline for switched fast full-duplex Ethernet, the average utilization limit of links should be 190%, and for switched shared fast Ethernet, the average limit of links should be 85% [25]. The projected growth in users, network services, business, etc. must be all taken into consideration to extrapolate the required growth capacity or the future growth factor. In our study, we will ascertain that 25% of the available network capacity is reserved for future growth and expansion. For simplicity, we will apply this evenly to all network resources of the router, switches, and switched-Ethernet links. However, keep in mind this percentage in practice can be variable for each network resource and may depend on the current utilization and the required growth capacity. In our methodology, the reservation of this utilization of network resources is done upfront, before deploying the new service, and only the left-over capacity is used for investigating the network support of the new service to be deployed.

3.4. Perform network measurements

In order to characterize the existing network traffic load, utilization, and flow,

network measurements have to be performed. This is a crucial step as it can potentially affect results to be used in analytical study and simulation. There are a number of tools available commercially and noncommercially to perform network measurements. Popular open-source measurement tools include MRTG, STG, SNMPUtil, and GetIF [26]. A few examples of popular commercially measurement tools include HP OpenView, Cisco Netflow, Lucent VitalSuite, Patrol DashBoard, Omegon NetAlly, Avaya ExamiNet, NetIQ Vivinet Assessor, etc. Network measurements must be performed for network elements such as routers, switches, and links. Numerous types of measurements and statistics can be obtained using measurement tools. As a minimum, traffic rates in bits per second (bps) and packets per second (pps) must be measured for links directly connected to routers and switches. To get adequate assessment, network measurements have to be taken over a long period of time, at least 24-h period. Sometimes it is desirable to take measurements over several days or a week. One has to consider the worst-case scenario for network load or utilization in order to ensure good QoS at all times including peak hours. The peak hour is different from one network to another and it depends totally on the nature of business and the services provided by the network.

Table 2 shows a summary of peak-hour utilization for traffic of links in both directions connected to the router and the two switches of the network topology of Fig.

1. These measured results will be used in our analysis and simulation study.

通信工程专业 本科毕业设计题目(DOC)

通信工程和电子信息工程专业 毕业设计参考题目 来源: 来源不限.. 科研生产实际自拟其它状态: 可选状态结束状态状态不限.. 列表按默认题目导师专业来源部门限选已选结束日期降序升序排列 自动化与电气工程系秦刚电子信息工程[需要1人] 已结束浏览详情 [1] 电缆隧道车转向控制系统的研究4004 张海宁专业方向不限[需要1人,已接受0人] 可选报 [2] 电动扭矩扳手设计还没有人选报！ 雷斌专业方向不限[需要1人] 已结束浏览详情 [3] 便携式水分数据采集仪设计与实现4018 王鹏专业方向不限[需要1人] 已结束浏览详情 [4] 基于WIFI的嵌入式图像监控系统--图像存储模块4023 张峰专业方向不限[需要1人] 已结束浏览详情 [5] 无线气压测量系统—接口及显示单元设计4015 雷斌专业方向不限[需要1人] 已结束浏览详情 [6] 基于Creator/V ega的试验水槽仿真模型的实现4031 雷斌专业方向不限[需要1人] 已结束浏览详情 [7] 靶场试验环境的虚拟现实场景建模4016 雷斌专业方向不限[需要1人] 已结束浏览详情 [8] 便携式热敏电阻测温缆数据采集仪设计4015 雷斌专业方向不限[需要1人] 已结束浏览详情 [9] 多路高精度计时及延时控制器通信接口设计4032 雷斌专业方向不限[需要1人] 已结束浏览详情 [10] 多路高精度计时及延时控制器人机接口设计4019 雷斌专业方向不限[需要1人] 已结束浏览详情 [11] 多路高精度计时及延时控制器设计与实现4032 雷斌专业方向不限[需要1人] 已结束浏览详情 [12] 水下激光靶目标检测器设计与实现4029 雷斌专业方向不限[需要1人] 已结束浏览详情

通信工程的论文.doc

通信工程的论文 随着我国经济的发展,通信技术得到了显著提升,促进了通信工程进一步发展。下文是我为大家搜集整理的关于的内容，欢迎大家阅读参考! 篇1 浅析移动通信中智能天线的原理及应用 1 前言 天线在移动通信中有效地实现了收发信机和电磁波传播空间之间的能量传递，是不可缺少的组成部分。而随着科学技术发展和进步，通信对器件、部件的要求也越来越高，智能天线变应运而生。智能天线是一种安装于基站的双向天线，它通过一组带可编程电子相位的固定天线单元获取针对覆盖的方向，同时能够获取基站和手机之间各链路的方向特性，利用数字信号处理技术，产生空间定向波束，使天线主波束对准用户信号到达方向，旁瓣或零陷对准干扰信号到达方向，达到充分高效利用移动用户信号并删除或抑制干扰信号的目的。随着4G技术的发展，智能天线技术更是成为移动通信系统研究中的热点。 2 智能天线的基本原理及实现 智能天线通常包括多波束智能天线(Switched Beam Antenna)和自适应阵智能天线(Adaptive Array Antenna)。智能天线技术主要基于自适应天线阵列原理，天线阵收到信号后，通过由处理器和权值调整算法组成的反

馈控制系统，根据一定的算法分析该信号，判断信号及干扰到达的方位角度，将计算分析所得的信号作为天线阵元的激励信号，调整天线阵列单元的辐射方向图、频率响应及其它参数。利用天线阵列的波束合成和指向，产生多个独立的波束，自适应地调整其方向，跟踪信号变化，对干扰方向调零，减弱甚至抵消干扰，从而提高接收信号的载干比，改善无线网基站覆盖质量，增加系统容量。 多波束天线利用多个并行波束覆盖整个用户区，每个波束的指向是固定的，波束宽度也随天线元数目而确定。随着用户在小区中的移动，基站相应选择不同的波束，使接收信号最强。自适应天线阵列一般采用4～16天线阵元结构，阵元间距为半个波长。天线阵元分布方式有直线型、圆环型和平面型。自适应天线阵列是智能天线的主要类型，可以完成用户信号接收和发送。该系统采用数字信号处理技术识别用户信号到达方向，并在此方向形成天线主波束。自适应天线阵列中，各天线元的放置形式可有多种，相邻天线元间距为一特定值。在接收信号到达天线阵时，每个阵元上的信号经过不同的加权，然后再叠加产生一个输出信号，加权系数和叠加可以根据不同的准则。 为了使智能天线具有良好性能，应根据具体的电波传播环境，选择相应的智能算法。采用软件无线电技术使系统具有良好的改善能力，提高系统性能。 3 智能天线的优点 智能天线可以从以下几个方面明显改善无线通信系统的性能，提高系统的容量：

通信工程专业导论论文

通信工程导论 论文题目 院系 专业 班级 学号 学生姓名 联系方式 年月 摘要 通信工程专业与信息的联系是密不可分的。信息是可以描述的客观现象，且具有一定物理含义的消息或知识，信息是可以用数值、文字、声音、图像等形式描述的状态，信息是用数据作为载体来描述和表达的客观现象，信息是对数据加工提炼的结果，是对人类有用的知识，信息是隐含在物理信号中具有一定含义的消息，信号处理的目的是为了从信号中获取有用的知识。信息技术的内涵包括传感，通信和计算机。主要分为两类：一类是管理信息系统；另一类是指面对自然科学领域的工程。 关键词：通信，技术，系统，光纤、数字微波、卫星、移动、3G、4G、CDMA 引言 在经过李老师的精彩讲解之后，我对通信工程专业有了更加清晰的认识，了解了通信专业的发展，我国目前通信产业的现状以及未来发展的方向。使我对自己未来大学四年的规划，目标更加明确。其中老师主要介绍了通信行业的发展趋势、通信系统的组成、通信工程专业的培养目标、通信工程专业的课程体系还有

与我们息息相关的生活方面的建议、简单说说毕业后的去向。在此表示衷心感谢！在科技发展如此迅速的今天，通信业在社会中占据着不可替代的地位，各种各样的信息每天都在变换着。何谓信息？不知道有多少人知道。从古老的结绳记事，烽火传烟，飞鸽传书，到当前的手机，网络，电话等等通信方式，人们的通信方式发生了翻天覆地的变化，变的更加方便，快捷，舒适，给人类的沟通带来了无与伦比的便捷，缩短了时空的距离，提高了沟通的效率，为经济发展全球化铺上了高速通道。可以说通信方式的发展促进了时代的进步，当然这离不开科技的发展，更重要的是离不开一门专业——通信工程的发展。合肥学院独具特色的第二课堂管理体系，使我校的办学能力不断的提升，下面将进行介绍。胡国华老师对我们通信工程专业的发展及就业方向、发展前景也进行了详细的介绍。下面我将给大家详细介绍。 目录 一、引子： (1) 二、通信工程的含义： (1) 三、通信工程专业的培养目标： (3) “平台+模块”形式的课程体系： (3) 四个平台+ 三个方向： (4) 四个平台 (4) （1）通识基础教育平台； (4) 三个方向 (4) 四、通信工程专业发展趋势和毕业生去向： (5) 光纤通信发展前景 (5) 无线通信发展前景 (5) 就业现状: (6) 就业前景: (6) 五、通信工程实验室建设背景： (7) 2、通信工程实训中心实验室建设内容 (7) 六、开设的实训项目 (7)

通信工程专业毕业设计题目

通信工程专业毕业设计题目 本文是关于通信工程专业毕业设计题目，仅供参考，希望对您有所帮助，感谢阅读。 第一类：通信工程设计1、通信网工程设计 2、程控室工程设计 3、传输室工程设计第二类：通信论文4、光城域网研究与组网 5、光波分复用技术的研究与分析 6、光同步数字体系的研究与分析7、论述移动通信的应用及发展 8、铁通XX 分公司宽带业务现状与发展 9、铁通XX分公司发展策略 10、提速铁路专用通信业务及发展 11、自拟与本职工作密切相关的通信工程专业课题第一类：通信工程设计题目要求《通信网设计》一、设计要求：1、作某一范围长途干线网设计； 2、绘出新设计通信网图并作相应阐述。二、主要内容：1、对通信网种类及构成要素作概括性阐述；2、拟定长途网业务节点数量及选用相应设备；3、对新设计通信网的信道构成特点、网型、保护方式等作相应阐述。《程控交换工程设计》一.设计要求:1.对原有设备情况的调查,收集各种资料 2.根据调查结果设计交换网图3.根据交换网图提出中继方式,其中包括信令方式,接口方式及传输方式等内容4.画出工程所需各部分图纸5.写出设计规范书及设计说明书二.完成图纸名称:1.交换网图 2.中继方式 3.设备平面布置图 4.总配线架,数字配线架端子分配图 5.电缆径路图 6.电源系统图7.工程数量表《传输室工程设计》一、设计要求：1、结合本单位条件或者处自拟条件作传输室施工设计，规模不限； 2、采用光纤传输设备或者数字微波设备及相关附属设备（如中配架、数配架、引入架、试验架等）；3、对各项设计作重点说明。二、主要内容：1、传输室设备平面布置图； 2、通信网图； 3、室内信道直线径路图； 4、中配架运用及分配图； 5、布线计划图改工程数量表。第二类：通信论文题目要求1、根据所选题目进行现场调研及收集资料；2、根据题目说明论文主要包括哪些部分；3、对每一部分作详细论述； 4、论文应包括论点、论据、论证过程及结论； 5、所涉及的数据、图表要准确； 6、论述过程中要有自己独创的观点；

《土木工程专业英语》段兵延第二版全书文章翻译精编版

第一课 土木工程学土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。 土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。 土木一词来源于拉丁文词“公民”。在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。 领域。因为包含范围太广，土木工程学又被细分为大量的技术专业。不同类型的工程需要多种不同土木工程专业技术。一个项目开始的时候，土木工程师要对场地进行测绘，定位有用的布置，如地下水水位，下水道，和电力线。岩土工程专家则进行土力学试验以确定土壤能否承受工程荷载。环境工程专家研究工程对当地的影响，包括对空气和地下水的可能污染，对当地动植物生活的影响，以及如何让工程设计满足政府针对环境保护的需要。交通工程专家确定必需的不同种类设施以减轻由整个工程造成的对当地公路和其他交通网络的负担。同时，结构工程专家利用初步数据对工程作详细规划，设计和说明。从项目开始到结束，对这些土木工程专家的工作进行监督和调配的则是施工管理专家。根据其他专家所提供的信息，施工管理专家计算材料和人工的数量和花费，所有工作的进度表，订购工作所需要的材料和设备，雇佣承包商和分包商，还要做些额外的监督工作以确保工程能按时按质完成。 贯穿任何给定项目，土木工程师都需要大量使用计算机。计算机用于设计工程中使用的多数元件（即计算机辅助设计，或者CAD）并对其进行管理。计算机成为了现代土木工程师的必备品，因为它使得工程师能有效地掌控所需的大量数据从而确定建造一项工程的最佳方法。 结构工程学。在这一专业领域，土木工程师规划设计各种类型的结构，包括桥梁，大坝，发电厂，设备支撑，海面上的特殊结构，美国太空计划，发射塔，庞大的天文和无线电望远镜，以及许多其他种类的项目。结构工程师应用计算机确定一个结构必须承受的力：自重，风荷载和飓风荷载，建筑材料温度变化引起的胀缩，以及地震荷载。他们也需确定不同种材料如钢筋，混凝土，塑料，石头，沥青，砖，铝或其他建筑材料等的复合作用。 水利工程学。土木工程师在这一领域主要处理水的物理控制方面的种种问题。他们的项目用于帮助预防洪水灾害，提供城市用水和灌溉用水，管理控制河流和水流物，维护河滩及其他滨水设施。此外，他们设计和维护海港，运河与水闸，建造大型水利大坝与小型坝，以及各种类型的围堰，帮助设计海上结构并且确定结构的位置对航行影响。 岩土工程学。专业于这个领域的土木工程师对支撑结构并影响结构行为的土壤和岩石的特性进行分析。他们计算建筑和其他结构由于自重压力可能引起的沉降，并采取措施使之减少到最小。他们也需计算并确定如何加强斜坡和填充物的稳定性以及如何保护结构免受地震和地下水的影响。 环境工程学。在这一工程学分支中，土木工程师设计，建造并监视系统以提供安全的饮用水，同时预防和控制地表和地下水资源供给的污染。他们也设计，建造并监视工程以控制甚至消除对土地和空气的污染。他们建造供水和废水处理厂，设计空气净化器和其他设备以最小化甚至消除由工业加工、焚化及其他产烟生产活动引起的空气污染。他们也采用建造特殊倾倒地点或使用有毒有害物中和剂的措施来控制有毒有害废弃物。此外，工程师还对垃圾掩埋进行设计和管理以预防其对周围环境造成污染。

通信工程毕业论文

档号：专业代码： 广东理工职业学院顶岗实习报告 系别工程技术系 学生姓名xxx 学生学号xxxx 学生班级10通信技术（1）班 专业名称通信技术 校内指导教师xx 校外指导教师xxx 实习单位xx 2013年4月26日

档 2013年4月26日 目录 一．实习单位介绍 (3) 1.广东超讯通信技术股份有限公司 (3) 二. 实习岗位及主要内容 (4) 1.实习目的 (4) 2.思想和纪律表现 (4) 3.实习岗位（管线割接员、管线，设备录入员） (4) 4.岗位要求及主要工作内容 (4) 三. 实习的主要过程 (5) 1、 autoCAD 以及 zwCAD的使用和看竣工图纸 (6) 2、管线割接 (7) 3、做管线割接方案传输设备工程搬迁、割接工作流程 (8) 4、做管线割接方案 (12) 5、OLT (13) 5、施工现场查勘 (14) 四. 实习总结 (16) 参考文献 (16) 致谢 (16) 附录 (16) 顶岗实习记录表及顶岗实习考核鉴定表················

一、实习单位介绍 1.XXXXX股份有限公司 XXX公司成立于 1998 年，是中国最早从事移动通信网络建设、网络维护、网络优化的公司之一，现已成长为集通信软硬件、系统集成、信息技术服务 一体的高科技企业。目前除在广州设有总部外，还在北京、广州、深圳、广西、 江西、四川、甘肃、内蒙古、海南、湖南、贵州等地建立了省级分公司及研发中心。 公司具备通信信息网络系统集成甲级资质、通信网络代维甲级资 质，已通过高新技术企业、软件企业、安全生产企业、ISO（ISO 9001 质量管理体系， ISO14001 环境管理体系、职业健康安全管理体系）等一系列资格认证。 成立至今，公司已经在通讯行业建立了稳定的市场基础和用户支持群体，并逐渐成为通信技术服务规范的发起者和倡导者。 公司充分发挥自身优势，不断完善、创新服务体系，为中国移动等运营商提供专业、优质的一体化服务。我们的合作伙伴有：中国移动、中国 电信、中国联通。 公司践行“每一比特都精雕细琢”的企业宗旨，秉承“客户、 员工、社会、资本共同获益”的经营理念，自主开发，勇于创新，致力于成为最 优秀的通信技术服务商。 超讯成立于 1998 年，是中国最早从事移动通信网络建设、网络维护、网络优化的 公司之一，现已成长为集通信软硬件、系统集成、信息技术服务一体的高科技企业。目前除在广州设有总部外，还在北京、广州、深圳、广西、江西、四川、

通信工程专业论文

摘要 通信工程（Communication Engineering）专业是信息科学技术发展迅速并极具活力的一个领域，尤其是数字移动通信、光纤通信、Internet网络通信使人们在传递信息和获得信息方面达到了前所未有的便捷程度。通信工程具有极广阔的发展前景，也是人才严重短缺的专业之一。本专业学习通信技术、通信系统和通信网等方面的知识，能在通信领域中从事研究、设计、制造、运营及在国民经济各部门和国防工业中从事开发、应用通信技术与设备。毕业后可从事无线通信、电视、大规模集成电路、智能仪器及应用电子技术领域的研究，设计和通信工程的研究、设计、技术引进和技术开发工作 Communication Engineering (Communication Engineering major is information and the rapid development of science and technology and a dynamic field, especially digital mobile communications, optical fiber Communication, Internet, network Communication makes people in the passing information and access to information has reached unprecedented convenience degree. Communication engineering has a very broad prospects for development, is also one of the serious shortage of professional talents. This professional learning communication technology, communication system and network knowledge, can in the field of communication research, design, manufacture, operation, and in the departments of national economy and defence industry engaged in the development and application of communication technology and equipment. After graduation can be engaged in wireless communications, television, large scale integrated circuit, intelligent instrument and application in the field of electronic technology research, design and communication engineering research, design, technology import and technology development work。 关键词： 前言： 在现代社会，经济高速发展，社会日益前进，广阔的经济前景离不开通信的发展。近几十年，全球通信迅猛发展，走在时代前沿。目前，现代通信已由原先单纯的信息传递功能逐步深入到对信息进行综合处理，如信息的获取、传递、加工等各个领域。特别是随着通信技术的迅速发展，如卫星通信、光纤通信、数字程控交换技术等的不断进步，以及卫星电视广播网、分组交换网、用户电话网、国际互联网络等通信网的建设，通信作为社会发展的基础设施和发展经济的基本要素，越来越受到世界各国的高度重视和大力发展。 在现代社会，通讯技术起到了关键作用。科学技术是第一生产力，既然是生产力，就会对社会的方方面面有决定作用。当然在强调技术对社会的决定作用时，不能片面地夸大技术的作用。技术不能简单的、直接的、唯一的决定社会生活。技术是整个社会大系统的组成部分，与社会的经济、政治、文化和社会生活紧密相关。特别是当今的高技术，它对社会经济、对社会生活质量、对社会关系的改变、对社会政治和社会文化，都有其决定性的作用和影响。马克思把科学技术首先看成是历史的有力杠杆，看成最高意义上的革命。他在评价近代技术的社会作用时说，蒸汽、电力和纺织机甚至是比巴尔贝斯、拉斯拜尔和布朗基诸位公民，更危险万分的革命家。列宁对科学技术的社会作用也给予了极高的评价，在他看来，技术进步“也是其他一切进步的动力，前进的动因”。 而通信技术在对社会发展及社会生活的方面，也存在着巨大作用。通信技术作为信息技术的重要组成部分，共同使人类进入了虚拟时代、数字时代。虚拟，就其本身来说，是数字化方式的构成，它是人类中介系统的革命。虚拟性激发了人们创造能力的巨大发展。通信技术的进步还改变了人们的某些生活方式。比如：过去人们要上邮局寄信，现在在家发个E-mail

通信工程专业英语论文设计

The General Situation of AT89C51 The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash Programmable and Erasable Read Only Memory (PEROM) and 128 bytes RAM. The device is manufactured using Atmel’s high density nonvolatile memory technology and is compatible with the industry standard MCS-51?instruction set and pin out. The chip combines a versatile 8-bit CPU with Flash on a monolithic chip; the Atmel AT89C51 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications. Features: ?Compatible with MCS-51?Products ?4K Bytes of In-System Reprogrammable Flash Memory ?Endurance: 1,000 Write/Erase Cycles ?Fully Static Operation: 0 Hz to 24 MHz ?Three-Level Program Memory Lock ?128 x 8-Bit Internal RAM ?32 Programmable I/O Lines ?Two 16-Bit Timer/Counters ?Six Interrupt Sources ?Programmable Serial Channel ?Low Power Idle and Power Down Modes The AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle

土木工程专业英语论文.doc

Building construction concrete crack of prevention and processing Abstract The crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure. Keyword: Concrete crack prevention processing Foreword Concrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and

电子与通信工程前沿技术系列讲座结课论文

电子与通信工程前沿技术 系列讲座结课论文 姓名：XXX 学号：XXXXXX 院系：XXXXXX 指导老师：XXXXXX 电子与通信工程前沿技术系列讲座结课论文 第一讲先进信号处理理论及在无线通信、多媒体等领域中的应用 这次报告主要讲了四方面的内容：分数阶傅里叶变换、压缩感知理论框架、无线通信系统信号处理领域和多媒体信号与信息处理领域。陈老师结合分数阶傅里叶变换理论及压缩感知理论，介绍了这些先进信号处理理论的发展研究状况，并通过实例给出了相关理论在无线通信和多媒体领域中的应用研究。接着，他讲述了自己主持的国家自然科学基金以及郑州大学与北京理工大学等院校联合在研的国家自然科学基金重点项目的研究进展。 第二讲未来通信技术——认知无线电与协作通信 穆晓敏讲课的主要内容有：当前频谱利用现状、静态频谱分配的瓶颈及解决方案以及当前遇到的问题，同时还向我们介绍了互联网+、智慧城市、人工智能（AI)、工业4.0、

DT时代等相关内容。 认知无线电技术已经向“网络与系统”的框架转变，为增强认知能力、降低认知成本，协作手段成为必然。物理层链路技术面临进一步提升性能的“瓶颈”，通过不同网络元素间的多维度协作提高系统整体性能是下一阶段移动通信系统增强的主要途径。在这一过程中，对环境背景信息和用户业务特征的广泛感知是智能化协作与联合资源管理的重要基础。认知无线电与多维度协作通信的结合将成为技术发展的必然趋势。 第三讲智能可穿戴设备概念、基于纺织纤维的可穿戴式产品 文老师主要向我们介绍了智能可穿戴设备的概念以及文老师所创建公司研发的基于纺织纤维的可穿戴产品。 智能可穿戴设备是应用穿戴式技术对日常穿戴进行智能化设计、开发出可以穿戴的设备的总称，如眼镜、手套、手表、服饰及鞋等。最早的可穿戴设备用于军事、户外运动、人体检测等。苹果手表、微软手环和谷歌眼镜是当前最热门的智能穿戴设备，国内也涌现出大量的可穿戴智能设备厂商，像小米手环等。 在不久的将来，智能可穿戴设备将成为人体的一部分，就像皮肤、手臂一样。在更远的未来，手机可能只需向人体植入芯片，而Siri将能直接通过对话帮你打电话，帮你订餐馆，了解你的一切隐私，跟你的亲密程度甚至超过你的家人——可能谷歌眼镜和苹果手表都不再是植入人体的芯片了，他们已经成为人体基因的一部分，可以参与人类的繁衍和进化。 第四讲嵌入式系统的开发

通信类毕业论文题目

毕业设计选题与任务书填写---李文海 毕业设计工作讲座---毕业设计选题与任务书的填写 一、毕业设计(论文)的目的与要求 有下述三个方面的作用 ·总结：对在学期间所学知识的检验与总结 ·培养：培养和提高独立分析问题和解决问题的能力 ·训练：使学生受到科学研究、工程设计和撰写技术报告等方面的基本训练 1.目的 (1)提高学生对工作认真负责、一丝不苟,对事物能潜心考察、勇于开拓、勇于实践的基本素质。 (2)培养学生综合运用所学知识，结合实际独立完成课题的工作能力。 (3)对学生的知识面、掌握知识的深度、运用理论结合实际去处理问题的能力、实验能力、外语水平、计算机运用水平、书面及口头表达能力进行考核。 2.要求 (1)进行综合运用所学知识去解决实际问题的训练,使学生的科

学实验和工程实践技能的水平、独立工作能力有所提高。 (2)要求一定要有结合实际的某项具体项目的设计或对某具体课题进行有独立见解的论证，并要求技术含量较高。 (3)设计或论文应该在教学计划所规定的时限内完成。 (4)书面材料:框架及字数应符合规定 3.成绩评定 (1)一般采用优秀、良好、及格和不及格四级计分的方法。 (2)评阅人和答辩委员会成员对学生的毕业设计或毕业论文的成绩给予评定。 4.评分标准 (1)优秀:按期圆满完成任务书中规定的项目;能熟练地综合 运用所学理论和专业知识; 有结合实际的某项具体项目的设计或对某具体课题进行有独立见解的论证，并有较高技术含量。 立论正确,计算、分析、实验正确、严谨,结论合理,独立工作能力较强,科学作风严谨;毕业设计(论文)有一些独到之处,水平较高。 文字材料条理清楚、通顺,论述充分,符合技术用语要求,符号统一,编号齐全,书写工整。图纸完备、整洁、正确。 答辩时,思路清晰,论点正确,回答问题基本概念清楚,对主 要问题回答正确、深入。

通信工程专业毕业论文

南阳理工学院本科毕业设计（论文）QAM传输系统的设计与实现 Design and Achievement Of QAM System 学院（系）：计算机与信息工程学院 专业：通信工程 学生姓名：林龙 学号：671068014 指导教师（职称）：郭常盈（讲师） 评阅教师： 完成日期：2012年4月 南阳理工学院 Nanyang Institute of Technology

QAM传输系统的设计与实现 通信工程专业林龙 [摘要]正交振幅调制QAM是一种相位和振幅联合控制的数字调制技术。它应用范围非常广泛，不仅在移动通信领域而且在有线电视传输、数字视频广播、卫星通信等领域都得到广泛应用。本文深入研究QAM调制解调的基本原理、系统结构及性能参数，实现QAM调制解调系统的Simulink仿真及性能分析；详细分析模拟信号数字化的基本理论及实现方法，实现差分脉码调制的Simulink仿真及性能比对；基于上述理论构建模拟信源QAM传输系统，并利用Matlab/Simulink进行建模仿真及性能验证。仿真结果表明，所构建的QAM数字传输系统可以实现模拟信号良好的传输。 [关键词] 数字传输；正交振幅调制；差分脉码调制；建模仿真 Design and Simulation of QAM System Communcation Engineering Major Lin Long Abstract :Quadrature amplitude modulation is a joint-controlled digital modulation technology of phase and amplitude. It is widely used not only in the mobile communication field, but also in other fields, such as wire television transmission field, digital video broadcasting, satellite communication, etc... This paper studies the basic principles of QAM modulation and demodulation, then simulates the whole 16QAM system and discusses performances of system by the simulink toolbox. This paper also analyses the basic principles and implementation method on digitalizing analog signals, then simulates the DPCM system and contrasts performances of system. At last, this paper designs a QAM transmission system of analog sources, then simulates the whole transmission system and comparing performances of system. The simulation shows analog signals can be transmitted correctly in the system designed in this paper. Key words: digital transmission; quadrature amplitude modulation; differential pulse code modulation; model and simulate

最新通信工程专业毕业论文

一、前言 在全社会对节能的重视，在绿色新能源的发展现状，贵州的一些偏远山区，由于地理条件和经济落后，能源短缺等原因，电力供应和电力成本高，当地的电力短缺，没有电，人们对权力的渴望来解决用电问题迫在眉睫，他们始终坚持这样一来国家能够稳定发展与经济也可以很好的发展。今天我省能够使用电网和其他的发电机来发电。不然，对我我省的地势环境，历史，远程用户发送电路具有功耗小，途中损失比较严重。各种网络的使用是很难能维护的，难以保障连续供电。 该论文依向着节约能源和建设绿色环保新能源的想法贵州的风能和太阳能的偏远地区并不突出，电力资源短缺，使用更少的功率特性的用户建议的应用在贵州省，小风光互补电源的设计问题。复合材料结构的系统设计，对DC/DC变换器模块的设计选择，最大功率合理选择（M或T）跟踪模式，能够完成最大功率监督，改变其费用，简单结构，依赖专门用电直流电池组充电的同时思考，在DC/DC模块为基础的变化，设计PLC作为主要控制部件，控制器采集数据，电池端电压，电流。 本文针对绿色能源的发展，新的节能减排和发展国家目前所倡导的和谐的解释人和社会发展的需求的发展，人与自然；同时，本研究也为其它地区的独立发电有一定意义。 1.1 论文课题研究的背景和意义 能量是物质基础，中国经济的增长和人民生活的关键。然而人类在利用化石 燃料时，也引发了剧烈的生态系统与环境污染破损等问题。最近，每个列国渐渐了解到能源对我们的重要，更明白了普通的能源使用过程当中对生态系统与环境系统破损。许多国家都根据国情出发，治理了环境的恶化，以及开发和利用可再生，无污染的新能源作为可持续发展的一个重要组成部分。 风能和太阳能是取之不竭, 用之有余的可再生能源，风力发电和太阳能发电系统在我国取得了广泛的使用，他们的发电形式都有其长处。在现实生活中的主导力量，但由于客观条件，有些地方无法实现电力的发展与建设。 在移动通信基站的建设，电力设备被应用到传统的最近市电或者小的发电厂，电力，存在以下问题：1)电盲；2)电压波动；3)雷击损坏；4)基站电源线被人为

土木工程专业英语结课论文

2012级土木工程（本）专业《土木工程英语》课程论文 论文题目：高层建筑防火的研究 Research of high-rise building fire prevention 专业班级： 学生姓名： 学号： 论文成绩： 评阅教师： 2015年11 月14 日

（一） 基于性能化防火设计方法的商业综合体典型空间防火优化设计研究 正文：改革开放以来，我国市场经济蓬勃发展，各种类型的商业建筑如雨后春笋般涌现。然而人们在享受高效便捷的购物消费和休闲娱乐的同时，商业综合体及其建筑群的巨大规模、多样功能、众多人数、复杂流线、与城市多层面多点衔接等特点，极大程度地增大了灾害风险，特别是城市和建筑中最易发生的灾种——火灾的风险。传统的建筑防火设计以“条文式”的防火规范为依据，无法满足部分现代商业综合体迅速发展的设计需要，当因结构、功能、造型等方面的特殊要求，出现现行国家消防技术规范中未明确规定的、现行国家消防技术规范规定的条件不适用的、依照国家消防技术规范进行设计确有困难的情况时，将采取针对性更强、更加先进、经济、合理、有效的性能化防火措施进行建筑和规划设计。与此同时，性能化防火设计方法以其在火灾场景和人员疏散模拟等方面的突出优势，也将被更多地运用于优化“条文式”防火设计规范框架内的规划与建筑方案设计。可见研究大型商业综合体的性能化防火设计措施，并利用性能化防火设计的方法调整优化规划与建筑设计以避免和减轻火灾危害是亟待解决的重要课题。本论文共分为十章，分别介绍了课题的研究背景与意义，国内外商业综合体性能化防火的研究现状，要素构成及火灾危险性，建筑的火灾机理与性能化防火设计参数，五大类商业综合体典型空间的防火优化措施，最后提出结论与展望。本文的核心研究内容是结合商业综合体空间要素构成特征的火灾特点以及建筑防火设计中的三个重要指标（防火分区、疏散距离、疏散宽度），提炼五大类商业综合体的典型空间，即密集空间、竖向贯通空间、超大水平开敞空间、狭长通道空间和地下空间，以建筑学和城市规划学的视角，一方面运用计算机技术，对“超规范”的设计方案进行性能化防火设计安全评价，另一方面对条文式规范框架内的设计方法进行优化。性能化防火策略作为消防设计乃至贯穿整个建筑、规划设计全过程的设计思路，已初步为我们展现出应用领域的美好前景，本文旨在进一步完善和发展以数字技术为基础的性能化防火设计方法，为建筑和城市减灾防灾目标的实现提供更有力的保障。

通信工程导论论文

通信工程导论论文 细心的你是否留意到，十年前港台电影中黑帮大佬手里可以用来砸人的“大哥大”，早已变得如此纤细轻巧、色彩缤纷，并且飞入寻常百姓之手；从前只有数月飞鸽传书才能联系的国外亲友可以用简单方便快捷的伊妹儿（E-mail）互致问候、即时聊天，甚至装上摄像头开个网络会议！这一切都应该归功于通信工程（Communication Engineering）技术的迅猛发展。如果让科学家们选出近十年来发展速度最快的技术，恐怕也是非通信技术莫属。那么让我们来多了解一下这个年轻而又略显“神奇”的专业吧。 1.通信工程专业简介： 1988年，教育部本科专业调整正式命名了通信工程（Communication Engineering）专业，并定义了该专业学习和研究的内容，涉及通信技术、各种媒体处理、通信系统与通信网以及各种信息的传输、储存、变换、处理、检测与显示技术与系统等。 通信工程（Communication Engineering）专业是信息科学技术发展迅速并极具活力的一个领域，尤其是数字移动通信、光纤通信、Internet网络通信使人们在传递信息和获得信息方面达到了前所未有的便捷程度。通信工程具有极广阔的发展前景，也是人才严重短缺的专业之一。本专业学习通信技术、通信系统和通信网等方面的知识，能在通信领域中从事研究、设计、制造、运营及在国民经济各部门和国防工业中从事开发、应用通信技术与设备。毕业后可从事无线通信、电视、大规模集成电路、智能仪器及应用电子技术领域的研究，设计和通信工程的研究、设计、技术引进和技术开发工作。近年来的毕业生集中在通信系统、高科技开发公司、科研院所、设计单位、金融系统、民航、铁路及政府和大专院校等。本专业本着加强基础、拓宽专业、跟踪前沿、注重能力培养的指导思想，培养德、智、体全面发展，具有扎实的理论基础和开拓创新精神，能够在电子信息技术、通信与通信技术通信与系统和通信网络等领域中，从事研究、设计、运营、开发的高级专门人才。 2.通信工程专业培养目标： 。本专业毕业生应具备良好的政治素质、文化素质、心理素质、身体素质；较高的业务素质（具有较扎实的理论基础，具有实践能力、创新能力和良好的职业道德）。具有良好的数学、物理基础；掌握电路理论、电子技术等方面的基础知识；掌握传输、交换、网络理论基础知识；掌握计算机软、硬件基础知识。毕业生应获得以下几方面的知识和能力： 1、电子技术应用方面的设计开发能力。 2、良好的外语应用能力。 3、计算机的应用与开发能力。 4、了解通信技术发展动态、学习通信新理论和新技术的能力。 5、通信系统和通信设备的科学研究和实践工作能力。 6、创新意识、国际意识和创新能力。 3.通信产业链及毕业生就业方向： 当大学生走出校园，进入通信这个行业的时候，会发现通信是个极其庞大

通信工程英语专业论文

On the deployment of VoIP in Ethernet networks: methodology and case study Khaled Salah, Department of Information and Computer Science, King Fahd University of Petroleum and Minerals, P.O. Box 5066, Dhahran 31261, Saudi Arabia Received 25 May 2004; revised 3 June 2005; accepted 3 June 2005. Available online 1 July 2005. Abstract Deploying IP telephony or voice over IP (V oIP) is a major and challenging task for data network researchers and designers. This paper outlines guidelines and a step-by-step methodology on how V oIP can be deployed successfully. The methodology can be used to assess the support and readiness of an existing network. Prior to the purchase and deployment of V oIP equipment, the methodology predicts the number of V oIP calls that can be sustained by an existing network while satisfying QoS requirements of all network services and leaving adequate capacity for future growth. As a case study, we apply the methodology steps on a typical network of a small enterprise. We utilize both analysis and simulation to investigate throughput and delay bounds. Our analysis is based on queuing theory, and OPNET is used for simulation. Results obtained from analysis and simulation are in line and give a close match. In addition, the paper discusses many design and engineering issues. These issues include characteristics of V oIP traffic and QoS requirements, V oIP flow and call distribution, defining future growth capacity, and measurement and impact of background traffic. Keywords: Network Design，Network Management，V oIP，Performance Evaluation， Analysis，Simulation，OPNET 1 Introduction