Architecture And Performance Of Fixed And Tunable Transmitter Combined TWDM-PON

TWDM-PON has been selected as a solution of NG-PON2,and it benefits a lot from its compatibility with the legacy PON and cost-efficiency.In the standard TWDM-PON,wavelengths are dedicated to users within each PON,which can not be shared among different ODNs.The utilization of the wavelength resource is not efficient.In modern city life,people go to work in business areas at daytime and go back to houses in urban areas at night.The periodic migration between business areas and urban areas causes the traffic to change regularly.The periodic rising and falling of the traffic in the geography and time domain,which is called “Tide Effect”,will cause problems in both the waste of resources and lack of network resources.Considering the problems above,based on the standard TWDM-PON architecture,we propose a novel fixed laser and tunable laser combined wavelength sharing TWDM-PON architecture.In the experiment,feasibility of the system and wavelength sharing have been demonstrated and proved.We also prove that the system features compatibility with the legacy PON,scalability,sharing ability,cost-efficiency and power saving.The main work of the proposed scheme has the following three parts:Firstly,fixed laser and tunable laser combined wavelength sharing TWDM-PON architecture has been proposed.In the architecture,we leverage the lower cost of fixed laser and agility of tunable laser.And the fixed lasers and tunable lasers will deal with the different kinds of traffic in the network separately.The background stable traffic will be treated with fixed lasers,and when the load rises in the network the dynamic bursty traffic caused by the tide effect will be done with tunable lasers.Secondly,wavelength sharing is achieved within the same ODN and among different ODNs.By utilizing the cyclic property of AWGR,several FSRs has been used.Any wavelength from the OLT side can be routed any ODN.Then wavelength can be shared in the same ODN and among different ODNs.To deal with the tide effect problem,the proposed architecture benefits from the wavelength sharing among different ODNs which will save some transceivers at OLT side compared with the transceivers fully deployed situation.Finally,feasibility has been confirmed by the experiment.We have tested the characteristic of several channels of DBR laser.The experiment confirmed the wavelength resource sharing mechanism.We also proved that the proposed architecture features compatibility with the legacy PON,pay-as-you-grow deployment,transceiver saving at OLT side and power saving.