Created by: runzhou jiang
Number of Blossarys: 1
English (EN) An analog or analogue signal is any continuous signal for which the time varying feature (variable) of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal.
模拟信号是指信息参数在给定范围内表现为连续的信号， 或在一段连续的时间间隔内，其代表信息的特征量可以在任意瞬间呈现为任意数值的信号。
Pulse-code modulation is a method used to digitally represent sampled analog signals.
脉冲编码调制，简称PCM，是数字信号是对连续变化的模拟信号进行抽样、量化和编码产生。
Broadband refers to the wide bandwidth characteristics of a transmission medium and its ability to transport multiple signals and traffic types simultaneously.
宽带意味着下载速率为4Mbps，上行为1Mbps，可以实现视频等多媒体应用，并同时保持基础的Web浏览和E-Mail特性。
Variable bitrate is a term used in telecommunications and computing that relates to the bitrate used in sound or video encoding.
可变比特率指在异步转移模式(ATM)中，一种支持具有平均和峰值业务参数的可变比特率的业务。
Root mean square, also known as the quadratic mean, is a statistical measure of the magnitude of a varying quantity. It is especially useful when variates are positive and negative.
Local area network (LAN) is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building using network media.
局域网是指在某一区域内由多台计算机互联成的计算机组。局域网是封闭型的，可以由办公室内的两台计算机组成，也可以由一个公司内的上千台计算机组成。
Static random-access memory (SRAM) is a type of semiconductor memory that uses bistable latching circuitry to store each bit.
存储单元的内容可按需随意取出或存入，且存取的速度与存储单元的位置无关的存储器，随机存储器又分为静态随机存储器和动态随机存储器。
Payload in computing (sometimes referred to as the actual or body data) is the cargo of a data transmission. It is the part of the transmitted data which is the fundamental purpose of the transmission, to the exclusion of information sent with it (such as headers or metadata, sometimes referred to as overhead data) solely to facilitate delivery.
信息净负荷是在STM-N帧结构中存放将由STM-N传送的各种用户信息码块的地方。
Reduced instruction set computing is a CPU design strategy based on the insight that simplified (as opposed to complex) instructions can provide higher performance if this simplicity enables much faster execution of each instruction.
精简指令集计算机是一种执行较少类型计算机指令的微处理器，起源于80年代的MIPS主机（即RISC机），RISC机中采用的微处理器统称RISC处理器。
An optical network unit (ONU) is a device that transforms incoming optical signals into electronics at a customer's premises in order to provide telecommunications services over an optical fiber network.
光网络单元是系统中局端的光线路终端(OLT)和用户端的光网络单元(ONU)是EPON的关键部分,而位于其中的交换芯片及其驱动程序是整个系统的核心,它们设计的好坏、运行性能的优劣。
Common-channel signaling (CCS),in the US also common-channel interoffice signaling (CCIS),is the transmission of signaling information (control information) on a separate channel from the data, and, more specifically, where that signaling channel controls multiple data channels.
共路信令是将语音通道和信令通道分离，在单独的数据链路上以信令消息单元的形式集中传送若干路的信令信息，现在一般多为“七号信令”(SS7)。
Dynamic bandwidth allocation is a technique by which traffic bandwidth in a shared telecommunications medium can be allocated on demand and fairly between different users of that bandwidth.
动态带宽分配(DBA)是一种能在微秒或毫秒级的时间间隔内完成对上行带宽的动态分配的机制，EPON的DBA设置是针对每个ONU的上行流量，GPON可以更细致。同时DBA可以提高PON端口的上行线路带宽利用率；可以在PON口上增加更多的用户；用户可以享受到更高带宽的服务，特别是那些对带宽突变比较大的业务。
A binary tree is a tree data structure in which each node has at most two child nodes, usually distinguished as "left" and "right".
在计算机科学中，二叉树是每个结点最多有两个子树的有序树。通常子树的根被称作“左子树”和“右子树”。二叉树常被用作二叉查找树和二叉堆或是二叉排序树。二叉树的每个结点至多只有二棵子树(不存在度大于2的结点)，二叉树的子树有左右之分，次序不能颠倒。二叉树的第i层至多有2的 i -1次方个结点；深度为k的二叉树至多有2^(k) -1个结点；对任何一棵二叉树T，如果其终端结点数(即叶子结点数)为n0，度为2的结点数为n2，则n0 = n2 + 1。
A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information.
调制解调器，是一种计算机硬件，它能把计算机的数字信号翻译成可沿普通电话线传送的脉冲信号，而这些脉冲信号又可被线路另一端的另一个调制解调器接收，并译成计算机可懂的语言。这一简单过程完成了两台计算机间的通信。
Secure Hypertext Transfer Protocol (S-HTTP) is a little-used alternative to the HTTPS URI scheme for encrypting web communications carried over HTTP.
安全超文本传输协议是一个https URI scheme的可选方案，也是为互联网的HTTP加密通讯而设计。S-HTTP定义于RFC 2660。是经超文本传输协议改造而来的。
The ATM Adaptation Layer (AAL) is designed to support different types of applications and different types of traffic, such as voice, video, imagery, and data. Its basic function is the enhanced adaptation of services provided by the ATM layer to the requirements of the higher layer.
宽带综合业务数字网(B-ISDN)协议参考模型的第三层。主要负责将高层应用的用户信息转换成适合于异步转移模式(ATM)层所要求的格式。标准协议的一个集合，用于适配用户业务。AAL分为会聚子层（CS）和拆装子层（SAR）。AAL有4种协议类型：AAL1、AAL2、AAL3/AAL4和AAL5分别支持各种AAL业务类型。
A motherboard (sometimes alternatively known as the mainboard, system board, planar board or logic board, or colloquially, a mobo) is a printed circuit board (PCB) found in all modern computers which holds many of the crucial components of the system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals.
主板，又叫主机板、系统板或母板；它安装在机箱内，是微机最基本的也是最重要的部件之一。 主板一般为矩形电路板，上面安装了组成计算机的主要电路系统，一般有BIOS芯片、I/O控制芯片、键盘和面板控制开关接口、指示灯插接件、扩充插槽、主板及插卡的直流电源供电接插件等元件。
A serial number is a unique code assigned for identification of a single unit. Although usually called a number, it may include letters, though ending with digits.
序列号就是软件开发商给软件的一个识别码，和人的身份证号码类似，其作用主要是为了防止自己的软件被用户盗用。用户要使用其软件就必须知道序列号。在用户注册的时候会根据用户软件所安装的计算机软硬件信息生成唯一的识别码，一般称作机器码，也叫序列号、认证码、注册申请码等。
In computer networking, Fast Ethernet is a collective term for a number of Ethernet standards that carry traffic at the nominal rate of 100 Mbit/s, against the original Ethernet speed of 10 Mbit/s.Of the Fast Ethernet standards 100BASE-TX is by far the most common and is supported by the vast majority of Ethernet hardware currently produced.
快速以太网，是目前主流100M网络的称呼，也是通常说的百兆网。快速以太网与原来在100Mbps带宽下工作的FDDI相比它具有许多的优点，最主要体现在快速以太网技术可以有效的保障用户在布线基础实施上的投资，它支持3、4、5类双绞线以及光纤的连接，能有效的利用现有的设施。
