sonet systems

Notes on data communication and network-wide area network SONET/SDHThe high bandwidth of optical fiber is suitable for carrying large amounts of data at the same time in today's high data rates and low rates. For this reason, optical fiber and the need for data rate or high-bandwidth transmission technology to develop together, and then there is a need for standardization, so the US organization (ANSI) and the European organization (ITU-T) the corresp

1. Introduction The Synchronous Optical Network (SONET, representing synchronous optical networking) is a standard for digital information communication using optical fibers. In order to transmit a large number of telephone and data services, it has been developed to replace the quasi-synchronous digital system (PDH) system, which is defined by Telcodia's gr-253-core. 2. Summary SDH (representing the synchronous Digital hierarchy) standard is based o

Synchronous Optical Fiber Network (SONET) is an optical fiber transmission standard that focuses on the physical layer in the OSI model structure. Like SDH in the world, SONET was initially designed for the transmission of voice traffic over optical fiber networks. Like the first layer physical layer protocol, SONET is also used to ensure communication between va

With the development of enterprises to a certain stage, with the needs of customers and the needs of their own management, many enterprises have successively performed ISO quality system certification and ERP resource system activation, in addition, the Rules and Regulations previously formulated by the enterprise form a state in which three management systems are in parallel. However, since each management system has its own characteristics, the aspe

Principles of database systems (I)-basic concepts of database systems and concepts of Database Systems Concept Model: (1) express the overall logical structure of the data, which is a comprehensive description of the data involved in the entire application project by the System user. (Overall) (2) modeling data from the perspective of user needs. (Viewpoint) (3

Embedded Systems and Embedded Operating Systems Zhang xiangxiao Jian, electrical college, Southwest Jiaotong University2004-10-2 This article introduces embedded systems and embedded operating systems in terms of concepts, features, and types.1. What is an embedded system?Embedded

(Reprinted) the operating system used in the embedded real-time system is called the embedded real-time operating system. It is both an embedded operating system and a real-time operating system. As an embedded operating system, it has the characteristics of common embedded software, such as cropping, low resource usage, and low power consumption; as a real-time operating system (this article discusses the features of real-time operating systems only

First, the three major Windows system history and its version connotation; Second, the three major Windows systems become the "mainstream" of the objective basis; Third, the current three major Windows systems of the latest, the highest version; The way, method and concrete steps of installing the three systems; The advantages and disadvantages of "New Instal

An embedded real-time operating system is called an embedded real-time operating system. It is both an embedded operating system and a real-time operating system. As an embedded operating system, it has the characteristics of common embedded software, such as cropping, low resource usage, and low power consumption; as a real-time operating system (this article discusses the features of real-time operating systems only for strong real-time operating

windows3.x and MS-DOS have been using the file allocation table (FAT) system; Windows95 is using the extended FAT file system; The WindowsNT file system also supports two 32-bit file system--windowsnt file System (NTFS) and High-performance file Systems (HPFS) while continuing to support 16-bit file systems. These file systems have their advantages and disadvanta

How Windows XP systems are upgraded to Windows 7 systems To address this situation, the System encyclopedia lists common XP upgrades to win 7 issue summaries for readers ' reference: 1. Can I upgrade directly from Windows XP to Windows 7? OK, no need to go through Vista Transit. 2. Can XP be upgraded in place (In-place) to Windows 7? No. Only Vista users can choose "in-place upgrades." Microsoft sa

It is often possible to use an operating system (such as Windows and Linux) because of the need for work or learning. The file systems supported by Windwos may be familiar, and the file systems supported by the Linux operating system may be unfamiliar. It is often necessary to copy files from Windows to the Linux system, which requires understanding the file systems