求一篇英文资料和翻译，我需要你们 求一篇3000字的科技英文资料附翻译
500\u5206\u6c42\u4e00\u7bc7\u8ba1\u7b97\u673a\u82f1\u6587\u8d44\u6599\uff0c\u4ee5\u53ca\u4e2d\u6587\u7ffb\u8bd1\uff0c\u8fdb\u6765\uff01Engineering seeks quality; software engineering is the production of quality software.
This book introduces a set of techniques which hold the potential for remarkable
improvements in the quality of software products.
Before studying these techniques, we must clarify their goals. Software quality is
best described as a combination of several factors. This chapter analyzes some of these
factors, shows where improvements are most sorely needed, and points to the directions
where we shall be looking for solutions in the rest of our journey.
1.1 EXTERNAL AND INTERNAL FACTORS
We all want our software systems to be fast, reliable, easy to use, readable, modular,
structured and so on. But these adjectives describe two different sorts of qualities.
On one side, we are considering such qualities as speed or ease of use, whose
presence or absence in a software product may be detected by its users. These properties
may be called external quality factors.
Under \u201cusers\u201d we should include not only the people who actually interact with the final
products, like an airline agent using a flight reservation system, but also those who
purchase the software or contract out its development, like an airline executive in charge
of acquiring or commissioning flight reservation systems. So a property such as the ease
with which the software may be adapted to changes of specifications \u2014 defined later in
this discussion as extendibility \u2014 falls into the category of external factors even though
it may not be of immediate interest to such \u201cend users\u201d as the reservations agent.
Other qualities applicable to a software product, such as being modular, or readable,
are internal factors, perceptible only to computer professionals who have access to the
actual software text.
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\u6700\u540e\uff0c\u5728\u672c\u6b21\u6bd5\u4e1a\u8bbe\u8ba1\u8fc7\u7a0b\u4e2d\u8fd8\u4f7f\u6d89\u53ca\u5230\u4e86\u529f\u80fd\u5f3a\u5927\u7684Protel99 SE\u8f6f\u4ef6\u7684\u4f7f\u7528\uff0c\u5e76\u5229\u7528\u6b64\u8f6f\u4ef6\u7ed8\u5236\u4e86\u7cfb\u7edf\u539f\u7406\u56fe\u3001\u5370\u5236\u7ebf\u8def\u677f\u56fe\u3002
\u5173\u952e\u8bcd\uff1a\u5355\u7247\u673a\u3001\u6e29\u5ea6\u4f20\u611f\u5668\u3001\u4e32\u884c\u901a\u4fe1\u3001\u6297\u5e72\u6270\u3001Protel99 SE
First, the current design is based on graduation MCU control systems. SCM introduced to the main components of the monitoring system and the architecture, design and principle, the realization of the automatic control system, for the normal operation of equipment for the conditions. Secondly, The graduation address system design used by the C8051F020 the performance and development of a comprehensive done presentation; Then right DS18B20 single-bus digital temperature sensor made of the performance; UART0 while on the way serial communication function and the analysis; Finally, SCM interference measurement system hardware and software design method also be discussed. The graduate design major applications C8051F020 microcontroller as a core element in the analysis and design on the part of the circuit was introduced. After repeated and the simulation running, debugging, revision, the final form of a complete set of procedures system. Practice has proved that the system stability, and they have the advantage of a simple hardware circuits, software functions, reliable control system, high cost performance, is practical and reference value. Finally, at the graduation design process also involving the powerful Protel99 SE software use, and the use of this software mapping diagram of the system, the PCB plans.
Keywords : microcontroller, temperature sensor, serial communication, interference, Protel99 SE
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\u7ffb\u8bd1\u662f\u5de5\u5177\u7ffb\u8bd1\u592a\u591a\u4e86:Single-chip, also known as single-chip microcontroller, it is not the completion of a logic function of the chip, but a computer system integrated into a chip. Speaking in general terms: a single chip has become a computer. Its small size, light weight, cheap, for the learning, application and development of facilities provided. At the same time, learning to use the principle of single-chip computer to understand and structure the best choice. Single-chip and computer use is also similar to the module, such as CPU, memory, parallel bus, as well as the role and the same hard disk memory, is it different from the performance of these components are relatively weak in our home computer a lot, but the price is low, there is generally no more than 10 yuan ...... can use it to make some control for a class of electrical work is not very complex is sufficient. We are using automatic drum washing machines, smoke hood, VCD and so on inside the home appliances can see it's shadow! ...... It is mainly as part of the core components of the control. It is an online real-time control computer, control-line is at the scene, we need to have a stronger anti-interference ability, low cost, and this is off-line computer (such as home PC) The main difference. By single-chip process, and can be amended. Through different procedures to achieve different functions, in particular the special unique features, this is the need to charge other devices can do a great effort, some of it is also difficult to make great efforts to do so. A function is not very complicated if the United States the development of the 50's series of 74 or 60 during the CD4000 series to get these pure hardware, the circuit must be a big PCB board! However, if the United States if the successful 70's series of single-chip market, the result will be different! Simply because the adoption of single-chip preparation process you can achieve high intelligence, high efficiency and high reliability! Because of the cost of single-chip is sensitive, so the dominant software or the lowest level assembly language, which is in addition to the lowest level for more than binary machine code of the language, since such a low-level so why should we use? Many of the senior's language has reached a level of visual programming Why is it not in use? The reason is simple, that is, single-chip computer as there is no home of CPU, also not as hard as the mass storage device. A visualization of small high-level language program, even if there is only one button which will reach the size of dozens of K! For the home PC's hard drive is nothing, but in terms of the single-chip microcomputer is unacceptable. Single-chip in the utilization of hardware resources have to do very high, so the compilation of the original while still in heavy use. The same token, if the computer giant's operating system and applications run up to get the home PC, home PC can not afford to sustain the same. It can be said that the twentieth century across the three "power" of the times, that is, the electrical era, the electronic age and has now entered the computer age. However, such a computer, usually refers to a personal computer, or PC. It consists of the host, keyboards, displays and other components. There is also a type of computer, not how most people are familiar with. This computer is smart to give a variety of mechanical single-chip (also known as micro-controller). As the name suggests, these computer systems use only the minimum of an integrated circuit to make a simple calculation and control. Because of its small size, are usually charged with possession of machine in the "belly" in. It in the device, like the human mind plays a role, it is wrong, the entire device was paralyzed. Now, this single chip has a very wide field of use, such as smart meters, real-time industrial control, communications equipment, navigation systems, and household appliances. Once a variety of products with the use of the single-chip, will be able to play so that the effectiveness of product upgrading, product names often adjective before the word - "intelligent," such as washing machines and so intelligent. At present, some technical personnel of factories or other amateur electronics developers from engaging in certain products, not the circuit is too complex, that is functional and easy to be too simple imitation. The reason may be the product not on the cards or the use of single-chip programmable logic device on the other.
千兆以太网是建立在以太网标准基础之上的技术。千兆以太网和大量使用的以太网与快速以太网完全兼容，并利用了原以太网标准所规定的全部技术规范，其中包括CSMA/CD协议、以太网帧、全双工、流量控制以及IEEE 802.3标准中所定义的管理对象。作为以太网的一个组成部分，千兆以太网也支持流量管理技术，它保证在以太网上的服务质量，这些技术包括IEEE 802.1P第二层优先级、第三层优先级的QoS编码位、特别服务和资源预留协议（RSVP）。
千兆以太网还利用IEEE 802.1QVLAN支持、第四层过滤、千兆位的第三层交换。千兆以太网原先是作为一种交换技术设计的，采用光纤作为上行链路，用于楼宇之间的连接。之后，在服务器的连接和骨干网中，千兆以太网获得广泛应用，由于IEEE 802.3ab标准（采用5类及以上非屏蔽双绞线的千兆以太网标准）的出台，千兆以太网可适用于任何大中小型企事业单位。
目前，千兆以太网已经发展成为主流网络技术。大到成千上万人的大型企业，小到几十人的中小型企业，在建设企业局域网时都会把千兆以太网技术作为首选的高速网络技术。千兆以太网技术甚至正在取代ATM技术，成为城域网建设的主力军。
千兆以太网的特点主要包括如下。
1．千兆位以太网提供完美无缺的迁移途径，充分保护在现有网络基础设施上的投资。千兆位以太网将保留IEEE 802.3和以太网帧格式以及802.3受管理的对象规格，从而使企业能够在升级至千兆性能的同时，保留现有的线缆、操作系统、协议、桌面应用程序和网络管理战略与工具；
2．千兆位以太网相对于原有的快速以太网、FDDI、ATM等主干网解决方案，提供了一条最佳的路径。至少在目前看来，是改善交换机与交换机之间骨干连接和交换机与服务器之间连接的可靠、经济的途径。网络设计人员能够建立有效使用高速、关键任务的应用程序和文件备份的高速基础设施。网络管理人员将为用户提供对Internet、Intranet、城域网与广域网的更快速的访问。
3．IEEE 802.3工作组建立了802.3z和802.3ab千兆位以太网工作组，其任务是开发适应不同需求的千兆位以太网标准。该标准支持全双工和半双工1000Mbps，相应的操作采用IEEE 802.3以太网的帧格式和CSMA/CD介质访问控制方法。千兆位以太网还要与10BaseT和100BaseT向后兼容。此外，IEEE标准将支持最大距离为550米的多模光纤、最大距离为70千米的单模光纤和最大距离为100米的铜轴电缆。千兆位以太网填补了802.3以太网/快速以太网标准的不足。
千兆以太网的构建
千兆以太网络是由千兆交换机、千兆网卡、综合布线系统等构成的。千兆交换机构成了网络的骨干部分，千兆网卡安插在服务器上，通过布线系统与交换机相连，千兆交换机下面还可连接许多百兆交换机，百兆交换机连接工作站，这就是所谓的“百兆到桌面”。在有些专业图形制作、视频点播应用中，还可能会用到“千兆到桌面”，及用千兆交换机联到插有千兆网卡的工作站上，满足了特殊应用下对高带宽的需求。
在建设网络之前，究竟用千兆还是百兆，要从实际出发，从应用出发，考虑网络应该具备哪些功能。不同的应用有不同的需求，而且几乎没有只有单一业务的网络。但是，在各种业务中，生产性业务肯定是优先级最高的。如果在网络中传输语音，那么语音业务也需要优先安排。如果对业务优先的需求很高，网络必须有QoS保证。这样的网络必须要智能化，在交换机端口能够识别是什么类型的业务通过，然后对不同的业务进行排队，为不同的业务分配不同的带宽，这样才能保证关键性业务的运行。数据业务本身是有智能的，不管多少带宽都可以传输，只是时间长短而已，但是语音或者视频就不一样了，如果带宽小了之后，马上就听不清楚了，或者图像产生抖动，这都是不允许的。所以QoS非常重要。对单纯的数据网络，在QoS方面的需求就很低。在规划网络的时候，必须先了解清楚哪些功能是必须的，哪些可以不考虑。例如，目前多址广播是比较重要的性能之一，如果需要在网络中传输图像，而网络不具备多址广播的特性，那么网络的带宽浪费就会非常严重，甚至根本无法实现。
千兆以太网国际标准
1997年1月，通过了IEEE 802.3z第一版草案；
1997年6月，草案V3.1获得通过，最终技术细节就此制定；
1998年6月，正式批准IEEE 802.3z标准；
1999年6月，正式批准IEEE 802.3ab标准(即1000Base-T)，可以把双绞线用于千兆以太网中。
千兆位以太网标准主要针对三种类型的传输介质：单模光纤；多模光纤上的长波激光（称为1000BaseLX）、多模光纤上的短波激光（称为1000BaseSX）；1000BaseCX介质，该介质可在均衡屏蔽的150欧姆铜缆上传输。IEEE 802.3z委员会模拟的1000BaseT标准允许将千兆位以太网在5类、超5类、6类UTP双绞线上的传输距离扩展到100米，从而使建筑楼宇内布线的大部分采用5类UTP双绞线，保障了用户先前对以太网、快速以太网的投资。对于网络管理人员来说，也不需要再接受新的培训，凭借已经掌握的以太网网络知识，完全可以对千兆以太网进行管理和维护。
千兆以太网的标准化包括编码/译码、收发器和网络介质三个主要模块，其中不同的收发器对应于不同的网络介质类型。1000BASE-LX基于1300nm的单模光缆标准时，使用8B/10B编码解码方式，最大传输距离为5000米。1000BASE-SX基于780nm的FibreChannel optics，使用8B/10B编码解码方式，使用50微米或62.5微米多模光缆，最大传输距离为300米到500米。连接光纤所使用的SC型光纤连接器与快速以太网100BASE FX所使用的连接器的型号相同。1000BASE-CX是一种基于铜缆的标准，使用8B/10B编码解码方式，最大传输距离为25米。1000BASE-T基于非屏蔽双绞线传输介质，使用1000BASE-T 铜物理层Copper PHY编码解码方式，传输距离为100米。1000BASE－T在传输中使用了全部4对双绞线并工作在全双工模式下。这种设计采用 PAM-5 (5级脉冲放大调制) 编码在每个线对上传输 250Mbps。双向传输要求所有的四个线对收发器端口必须使用混合磁场线路，因为无法提供完美的混合磁场线路，所以无法完全隔离发送和接收电路。任何发送与接收线路都会对设备发生回波。因此，要达到要求的错误率（BER）就必须抵消回波。1000BASE－T无法对频率集中在125MHz之上的频段进行过滤，但是使用扰频技术和网格编码能对80MHz之后的频段进行过滤。为了解决5类线在如此之高的频率范围内因近端串扰而受到的限制，应该采用合适的方案来抵消串扰。
最初的千兆以太网采用高速780纳米光纤信道的光元件传输光纤上的信号，采用8B/10B的编码和解码方法实现光信号的串行化和复原。目前光纤信道技术的数据运行速率为1.063Gbps，将来会提高到1.250Gbps，使数据速率达到完整的1000Mbps。对于更长的连接距离，将采用1300纳米的光元件。为了适应硅技术和数字信号处理技术的发展，应在MAC层和PHY层之间制定独立于介质的逻辑接口，以使千兆以太网工作在非屏蔽双绞线电缆系统中。这一逻辑接口将适用于非屏蔽双绞线电缆系统的编码方法，并独立于光纤信道的编码方法。下图说明了千兆以太网的组成。
如何升级至千兆以太网
把10M、100M网络升级至千兆的条件并不多，最主要的是综合布线条件。千兆以太网指的是网络主干的带宽，要求主干布线系统必须满足千兆以太网的要求。如果原来的网络覆盖距离相隔几百米至几公里的多幢建筑物，则原来的主干布线一般采用的是多模或单模光纤，能够满足千兆主干的要求，可以不必重新敷设光纤了。在建筑物之间的距离小于550米的情况下，一般敷设价格相对低廉的多模光纤就可以满足千兆以太网的需要。
如果原来的网络只覆盖了一幢建筑，而且最远的网络节点与网络中心的距离不超过100米，则可以利用原来的5类或超5类布线系统。如果原来的布线系统达不到5类标准，或者采用了总线型布线系统而不是星型布线系统，则必须重新布5类线。
升级至千兆以太网，首先要将网络主干交换机升级至千兆，以提高网络主干所能承受的数据流量，从而达到加快网络速度的目的。以前的百兆交换机作为分支交换机，以前的集线器则可以在布线点不足的地方使用。目前千兆交换机的产品已经很多，可以根据网络的要求和预算等实际情况选择。
网络上的服务器需要吞吐大量的数据，如果网络主干升级至千兆，但是服务器网卡还停留在百兆的水平上，服务器网卡就会成为网络的瓶颈，必须使用千兆网卡才能消除这个瓶颈，解决方法是在原来的服务器上添加千兆网卡。注意应该优先选购64位PCI的千兆网卡，其性能比普通PCI千兆网卡高一些。千兆网卡可以根据网络的要求和预算等实际情况选择。
网络主干升级了，网络的分支也应随之升级。如果原来的用户计算机已经安装了10M/100M自适应网卡，则可以不必升级网卡，只要将网卡接到百兆交换机上就可以了；如果原来使用的是10Mbps网卡，则需要将网卡更换为10M/100M自适应网卡，这样才能提高工作站访问服务器的速度。
Thousand trillion ether nets
Thousand trillion ether nets are establishments in the ether net standard foundation on of technique.Thousand trillion ether nets and a great deal of ether net of usages with fast ether net complete and permit, and made use of original ll technical specifications that the ether net standard rules, among them including agreement of CSMA/ CD, ether net, a works, the discharge control and 802.3 management object for defines of IEEE.Be the ether net of a constitutes the part, thousand trillion ether nets also support the discharge management technique, it guarantees the service quantity in the ether net, these techniques include the IEEE 802.1 P second floor has the initiative the class, the third layer has the initiative the class of QoS code the , special service and resourceses to reserve the agreement( RSVP).
Thousand trillion ether nets still make use of the IEEE 802.1 QVLAN support, the fourth layer filter, gigabit the third layer exchange.Thousand trillion ether nets at first are to be a kind of exchange the technique design of, adoption the fiber optic conduct and actions north bound network, used for the conjunction between the building 宇 .After, in the conjunction and the framework nets of the server, thousand trillion ether nets acquire the extensive application, because of a set of the IEEE 802.3 ab standard( adopt 5 type and above and not shield the double to wring line of thousand the trillion ether net standard), thousand trillion ether nets are applicably in any big in small scaled business unit of 企 .
Currently, thousand trillion ether nets have already develop to become the essential network technique.Big go to the large business enterprise of the thousands person, small go to the medium small scaled business enterprise of several ten people, while constuct the area net of the business enterprise bureau would thousand trillion ether net techniques be a the head choose of high-speed network technique.Thousand trillion ether net techniques even just replace the technique of ATM, become main soldier of the city area net construction.
Thousand characteristicses of the trillion ether nets mainly include as follows.
1. the gigabit ether net provide perfect the migration path that did not lack, the full protection investment in existing network infrastructure.The gigabit ether net will reserve the IEEE 802.3 and a format of the ether net and 802.3 be object by the management specification, can thus make business enterprise reserved the existing cable, operate system, negotiated at the time of upgrading to thousand trillion functions, the table's top application procedure and networks manage the strategy and tools;
2. the gigabit ether net is is opposite in the originally possessed fast ether net, FDDI, ATM etc. main stem net solution, providing a best path.See currently at least, is the path that the improvement exchanges the machine and exchanges the credibility of a conjunction for a framework of the machine to connect and exchange machine with the server, economy.The network designs high-speed infrastructure of the applied procedure and the document backup that the personnel can build up the valid usage high speed, the key mission.The manager of the network will provide faster interview to the Internet, Intranet, the city area net and wide area network for the customer.
3. IEEE 802.3 the work set built up the 802.3 zs and the 802.3 ab gigabit ether nets to work set, its mission is a development to adapt the different and demanding gigabit ether net standard.That standard supports a workses and a work of half 1000 Mbpses, the homologous operation adoption IEEE 802.3 a format and CSMA/ CDs of the ether net lie the quality interview control method.The gigabit ether net still wants with the 10 BaseTs and 100 BaseTses backward and permit.In addition, the standard of IEEE will support biggest be apart from the copper stalk electric cable that are fiber-optic and biggest for the single mold of 70,000 meters to be apart from to 100 meters for many mold fiber optic, biggest distances of 550 meters.The gigabit ether net filled up 802.3 ether nets/ the shortage of the fast ether net standard.
Thousand trillion ether nets set up
Thousand trillion ether networks is exchanged the machine by thousand trillions, thousand trillion net cards, comprehensive cloth line system etc. constitute.Thousand trillions exchange the framework part that the organization became the network, thousand trillion net cards find job for on the server, passing the cloth line system and exchanging the machine to connect with each other, thousand trillions exchange the machine, the underneath can also link many 100 trillions to exchange the machine,100 trillions exchange the machine conjunction work station, this is so-called"100 trillions arrive table's top".In some professional sketch creation, video frequencies order sow apply, may still use" thousand trillions go to table's top", and use up the work station that thousand trillions exchange the machine 联 to go to put to have thousand trillion net cards, satisfying under special application to the need of the high bandwidth.
Before constuct network, use thousand trillions or 100 trillionses actually, want from set out physically, set out from the application, consider which functions should network have.The different application contain different need, and almost did not only have the network of the one business.But, in various business, the production business affirmation is to have the initiative the class tallest.If deliver the speech in the network, so the speech business also needs to have the initiative the arrangement.If is very high to the need that business have the initiative, the network must have the assurance of QoS.Such network must the intelligence turn, at exchange the machine port and can identify is what type of business pass, then carry on line up to the different business, assigning the different bandwidth for the different business, then can guarantee the movement of the decisive business thus.The data business is to have the intelligence of, no matter how much bandwidths it is can deliver, just that time length, but speech or the video frequency was different, if the bandwidth canned not hear clearly right away after is small, or the picture creation trembles to move, this is all something to disallow.So the QoS is count for much.To the pure data network, in the QoS need very low.At the time of programing the network, must understand first clear which functions is must of, which can take no account of.For example, many address broadcast is one of the more important functions currently, if need to deliver the picture in the network, but the network does not have the characteristic of many address broadcast, so the bandwidth of the network waste would be very serious, even basically can't carry out.
Thousand international standard of the trillion ether net
In January 1997, passed the 802.3 zs version 1 drafted plan of IEEE;
In June 1997, the drafted plan V3.1 be pass, the end technique detail draws up now;
In June 1998, the formal approval IEEE 802.3 z standard;
In June 1999, the formal approval IEEE 802.3 ab standard( namely 1000 Bases- T), can wring the line to the double to used for thousand trillion ether nets in.
The gigabit ether net standard mainly aims at three the category type deliver to lie the quality:Single mold fiber optic;Many long wave laser( be called the 1000 BaseLXs)s of mold fiber optic, many short-wave lasers of mold fiber optic;( be called the 1000 BaseSXs)The 1000 BaseCXs lies the quality, should lie quality can 150 姆 copper cables of Europe shield in the well balanced up deliver.The 1000 BaseT standard that the IEEE 802.3 z committee imitate allows to wring the gigabit ether net at 5 types, super 5 types,6 UTP doubleses on-linely to deliver the distance to expand to 100 meters, thus making the big part of construct the building universe cloth line adopt 5 UTP doubles to wring the line, guaranteeing the customer in times before to the ether net, fast investment of the ether net.For the network manager to say, also not need to accept again the new training, the ether net network knowledge that have already control with borrow, can carry on the management and maintenances to thousand trillion ether nets completely.
Thousand trillion ether nets standardize to include the coding/ translate the different from network lie three main molds of quality piece, among them transceiver of code, transceiver to should lie the quality type in the different network.1000 BASEs- LX according to the single mold fiber optic cable standard of the 1300 nms hour, use the 8 Bs/10 B coding decoding method, biggest deliver to be apart from to 5000 meters.1000 BASEs- SX according to the FibreChannel optics of the 780 nms, use the 8 Bs/10 B coding decoding method, use 50 microns or 62.5 many mold fiber optic cables of microns, biggest deliver to be apart from to 300 meters 500 meters.Connect a fiber optic that fiber optic use conjunction machine with the model number homology of the conjunction machine that the fast ether net 100 BASE FX use.The 1000 BASEs- CX is a kind of according to the copper cable of standard, use the 8 Bs/10 B coding decoding method, biggest deliver to be apart from to 25 meters.1000 BASEs- T according to shield the double to wring the line to deliver to lie the quality not, use the 1000 BASEs- T copper physics layer Copper PHY to code to decode the way, deliver to be apart from to 100 meters.The 1000 BASE － T in the middle of deliver used all 4 rightnesses of doubles to wring the line to combine the work under a works mode.This kind of design adoption PAM-5(5 class pulses enlarge to make) code at each line to up deliver the 250 Mbpses.Double to deliver to request four ll lines and must use the hybrid magnetic field circuit to the transceiver port, can't provide the perfect and hybrid magnetic field circuit, so can't insulate to send out and receive the electric circuit completely.Any send out and receive the circuits and will take place to return to wave to the equipments.Therefore, the mistake rate( BER) that toes attain the request must offset to return to wave.The 1000 BASE － T can't is concentrated to the frequency at the 125 MHzs on of segment of 频 carry on the percolation, but use the technique of 扰频 and meshs to code the ability to the 80 MHzs after of segment of 频 carry on the percolation.For solving 5 lines within the scope of such of high frequency the restrict that be subjected to because of near carry a string of 扰 , should adopt the fit project to offset a string of 扰 .
First of thousand the high-speed 780 the 纳 rices fiber optic of the trillion ether net adoptions believe the signal that the light component of the way delivers the fiber optic, the coding that adopts the 8 Bs/10 Bs reaches agreement the string that the code method carries out the light signal to go to turn and restore to original.Currently the data of a technique of fiber-optic letter circulates the velocity as 1.063 Gbpses, will raise the 1.250 Gbpses in the future, the 1000 Mbpses that make the data velocity attain the integrity.For the longer conjunction distance, will adopt the light component of 1300 rices of 纳 .Handle the technical development for the sake of the orientation 硅 technique and numerical signal, should in an establishment of the MAC layer and PHY layer independently in lie the logic of the quality to connect, to make thousand trillion ether nets to work in not shield double wring the line electric cable system.This logic connects the coding method that a people will be applicable to shield the double to wring the line electric cable system not, and independence in the coding method that the fiber optic believes the way.Next the diagram explained that thousand trillion ether nets constitute.
How upgrade to thousand trillion ether nets
Combine the condition that the 10 Ms, the 100 M network upgrades to thousand trillions not much, most is comprehensive cloth lines piece.What thousand trillion ether nets point is the bandwidth of the network lord stem, request the main dry cloth line system and must satisfy thousand requests of the trillion ether nets.If the original network overlays several buildings that the distance is separated several 100 meters to a few kilometers, then originally main dry cloth line is generally what to adopt is many molds or single mold fiber optic, can satisfy thousand requests of the trillion lord stems, need not the 敷 re- establish the fiber optic.Under the condition of distance between building is is small in 550 meters, the general 敷 establishes the price, opposite and cheap many mold fiber opticses can satisfy thousand demands of the trillion ether nets.
If the original network overlaid a building only, and the distance of the farthest network node and the network center not over 100 meter, then can make use of originally of 5 types or super 5 cloth line systemses.If the original cloth line system can not reach 5 standards, or adopted a cloth of total line line system but is not a cloth of star line system, then must afresh 5 lines of cloth.
Upgrade to thousand trillion ether nets, want to attain main stem of network exchanges the machine to upgrade to thousand trillions, to raise the data discharge that main stem of network can bear, thus quickly first the purpose of the network speed.The 100 trillions of the past exchange the machine to be the branch commutation machine, past of gather the line machine and then can order in the cloth line shortage of place usage.Currently thousand trillions exchange the product of the machine already a lot of, can the actual circumstances such as request and budget etc. choice of the basis network.
The server on the network needs to swallow to vomit a great deal of data, if the network lord stem upgrades to thousand trillions, but the server net card still stays around 100 levels of the trillions up, the server net card will become the bottleneck of the network, must use thousand trillion net cards and then can remove this bottleneck, solving the method to increase thousand trillion net cards on the original server.The attention should have the initiative thousand trillion net cards of make choice of purchase 64 PCIses, its function is higher and some than thousand trillion net cards of common PCI.Thousand trillion net cards can the actual circumstance choices such as request and budget etc. of the basis network.
The main stem of network upgraded, the branch of the network also should upgrade immediately.If the original customer calculator has already installed the 10 Ms/100 Ms from the orientation net card, then need not upgrade the net card, only receive the net card the 100 trillions commutation is on board all right;If originally what to use is the 10 Mbps net card, then needing to replace the net card as the 10 Ms/100 Ms from the orientation net card, then can raise the speed of the work station interview server thus.
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上面应该有啲
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