The SDH Technology And Application In Jilin Province Special Communication Transmit Network

With communication development,SDH technology has become noticed focus.And it's technology standard become more and more grown.The purpose of this design is to reconstruct and improve the shortages,structure and functions of the southern loop of Jilin Province special communication transmit network.The design is based on the former G.652 fiber,and through reconstruction and dilation of the SDH transmit network in existence,make the southern loop a transmit network,in which the STM-16 Double-cable-double-direction Duplication Step Sharing Protective Loop is the backbone layer,STM-4,1 channel protective loop is the accessing layer in part of the areas.The aim of the design is to solve the bottle-neck problems of the transmit networks and improve the security of the network.The former network is chain-structured including more than 20 STM-16,4,1 chains which can lead to security problems.As the developing of the new business and other data operation of Special Network,the time slot capability of the transmition syntaxis layer can not feed the need of the newly added operations. The core technology of this design is the SDH technology hierarchy.We discuss the principles of SDH at this design:that is the SDH generated technology background,frame configuration and duplication steps,segment overhead,pointers and timer requirement of SDH facility timer clock.The equipment in this transmit network design is ZTE Unitrans^?ZXSM,Unitrans^? ZXMP,at the same time;we also introduce the logic constitution of the SDH appliance.Finally,we introduce the network constructing mode and the design of various parameters in the transmit process,which include the error code performance,the fiber relay segment distance,dithering performance and the dithering performance requirement of PDH/SDH network boundary.We can get the design scheme from the design theory above:1.We can design the time slot in the southern loop network which is based on the 2.5 GB/s SDH service chart.2.We choose to use duplication segment inversed loop working mode considering all the aspects including the protecting/recovering time,crossing link problem and end to end protection.3.We can design the time clock synchronous system chart based on the time clock synchronous requirement.