双绞线电缆的特性与分类

The Physical Properties of Fiber-optic Cable and Transmission Principle

双绞线电缆,是由按一定密度的螺旋结构排列的两根包有绝缘层的铜线外部包裹屏蔽层或橡塑外皮构成的。一般在一根电缆中包含多对双绞线,线对数量视用途在2～1800对之间,连接计算机终端的双绞电缆通常包含2对或4对双绞线。双绞线电缆分为屏蔽双绞线和非屏蔽双绞线两大类。按传输质量分为1～5类,局域网中常用的为3类、4类和5类双绞线。为适应网络速度的不断提高,又出现了超5类和6类双绞线,其中6类双绞线可满足最新的千兆以太网的高速应用。双绞线电缆主要用于星型网络拓扑结构,即以集线器或网络交换机为中心,各网络工作站均用一根双绞线与之相连,这种拓扑结构非常适用于结构化综合布线系统,可靠性高。任一连线发生故障时,不会影响到网络中的其他计算机,故障的诊断和修复也比较容易。

Twisted pair cable,is made up of coated copper wire wrapped outside the shielding layer or rubber sheath.The copper wire is a certain density of spiral structure arranged two insulation layer。In general a cable contains multiple twisted pair line,The amourt of the pair line is from 2 to 1800 according to the quantity of use.The connection terminals usually contains 2 or 4 pairs of twisted pair.Twisted pair cable includes two categories of twisted pair shielded and unshielded twisted pair.Twisted pair line is divided into 1 to 5 categories.accord ing to the transmission quality,Twisted pair line is usually used in the3 category,category 4 and category 5 in the LAN.In order to adapt to the network speed and continuous improvement,super category 5and category 6 twisted pair emerged.The category 6 twisted pair can meet the latest Gigabit Ethernet for high-speed applications.Twisted pair cable is mainly used for the star network topology,i.e.to a hub or switch network as the center,the network workstation with a twisted pair is connected,the topology is very suitable for structured cabling system,high reliability.If Any connection fails,that will not affect the other computers on your network,Also,fault diagnosis and repair is relatively easy.