Design And Implementation Of ROADM Board Based On ARM

Transmission problem of mass data between terminal and terminal can be solved by WDM(Wavelength Division Multiplexing)optical network,but it cannot settle the problem of upload and download data business in relay station.With the arrival of 5G,the data business forwarding in relay station will be larger and larger.Therefore,WDM optical network must be developed into OTN(Optical Transport Network)optical network.OTN network inherits the advantages of WDM and adds electric crossing and optical crossing.The core equipment of optical crossing is ROADM(Reconfigurable Optical Add-Drop Multiplexer)which can realize upload,download and reconstruction of wavelength by remote configuration in relay station.Compared with WDM,OTN optical network consisted of ROADM uploading or downloading business without OEO conversion can be more flexible and carry larger volume of business.Besides,it with higher economic value has lower cost in term of network construction.At present,the ROADM system on the market is mainly too complex and lack of dimensions.The complexity of ROADM system will lead to the difficulty of fiber connection.At the same time,lacking of dimensions in current ROADM system will cause inability of large-scale optical network.In order to deal with the problem of existing ROADM equipment,a high-density ROADM equipment which branch unit is integrated with circuit unit and supporting 20-dimension has been designed.The content of this paper can be summarized as following: Firstly,the working principles of three generation commercial ROADM system and the technology of WSS(Wavelength Selective Switch)have been introduced in this paper,then application scenarios is given,and the system structure of the ROADM equipment is introduced according to the application scenario.Secondly,the hardware structure of ROADM is designed by taking the system structure of the ROADM equipment as a reference.Starting from the selection of control chip,interface circuit of each functional module whose operatingcharacteristic has been studied is designed in detail.Thirdly,the software design which is divided into several functional modules including WSS,EDFA,OPM(Optical Performance Monitor)and TRANSCEIVER are carried out to realize the function of ROADM system.Finally,the optical index test and system function test of the implemented ROADM board are carried out in detail.The result indicates that the ROADM board can upload/download or reconstruct wavelength accurately within the error of 0.5dB in input-output port.In addition,topological logic of each port can be found within 15 min when the client side is fully load.Meanwhile,the error of OPM power balance is less than 0.5dB.The deadlock problem caused by OSC can be solved effectively EDFA functional module by in APR.