Research And Implementation Of Wideband High Resolution Frequency Synthesizer

Transmission network,as the most elementary network of service providers,supports various operations.It provides communication channels with different equipments which could exchange information.Provincial trunk transmission network acts as a switch of provincial network and local network,and functions as a relay between different provincial and city operations.DWDM + SDH as a major carrying technology has existed for a long period.SDH,electric cross connection,with great protect function and OAM function,smaller granulation and limited capacity,can turn on and turn off services flexibly.DWDM,multi-wavelength multiplex boost the capacity,but lacking data protection,simple point-to-point networking mode,weakens the data protection ability and holds down the OAM function.Meanwhile,DWDM,with insufficient protection methods,are not doing well in service stability and vulnerable to the poor quality of fiber-optical and equipment flaws.From the perspective of service requirements,with enhancement of household bandwidth,public internet service will bring the explosive growth of the upstream bandwidth of core routers.As mobile core network service became IP network.Change from traditional TDM circuit to IP circuit.Fixed network soft switch service,turns to IP network,dues to shrinking of traditional fixed-line business and the progression of IMS,turns to the IP-based service.High bandwidth,large granularity will be the mainstream of trunk network service.To adapt to the new requirement as following: service volume increasing,lengthen of transmission distance,a complexity of building networks,increase number of nodes.We need to adjust the original method of building the network,develop multiple transmission technologies.Sichuan province transmission network was composed of DWDM+SDH,the capacity,protection,and access capacity would not satisfy network and business development requirement.A new transmission network OTN(Optical Transport Network)is urgently needed.It has the advantages of SDH and DWDM,and multiplex client side service.Such as STM-N,ATM,IP,ethernet into paths of OTN,single wavelength bandwidth will be expanded to 10 G,40G,and 100 G,and optical cross connection ability will reach tens of Tbps;it can provide auto protection and recovery,high QoS guaranty,suits the requirement of networks and services.This paper analyzes DWDM+SDH trunk transmission network,one of Sichuan service providers,and summarize the condition of fiber-optical and current network loading ability.Make an evaluation of the current situation and future development.Then draw a conclusion,to build a new OTN system as the new core-carry-network.After considering abolish of DWDM in the future,the new OTN system will be designed and implemented.After system test and a test run,we will adjust and optimize the network,to suit it better to the business layout of a service provider.