The Research Of Passive Optical Network Based On WDW

With the rapid development of multimedia business, users’ demands on the rateof access networks are increasing quickly. The bandwidth requirements of individualusers will achieve more than Mbit/s over the next few years, and the number ofrequirements will be increased by10times every three to five years.Currently, cable access network is almost based on DSL technology andTDM-PON technology. But the DSL technology can only provide users uplink rate1.5Mbit/s and downlink rate8Mbit/s at most. TDM-PON can usually provide2.5Gbit/s downlink rate and1.25Gbit/s uplink rate,but the rate divided into each partof users is generally8Mbit/s or10Mbit/s, and the top rate can only achieve20Mbit/s. Obviously, the access rate of DSL and TDM-PON technology can’t satisfythe needs of users’, so the access network becomes the "bottleneck" of thetelecommunication network.To solve the "bottleneck" problem of access network, this paper had talks abouttwo WDM-PON solutions in the access network and makes simulation. One solutionis the scheme based on broad light spectral slicing and the other one is based onRSOA re-modulation.The scheme based on broad light spectral slicing had the problem that the powerafter sliced was too low and the width of broad light was not enough in the past for along time. In this paper, the LED source with high power and broad spectral are used.And the width of the slices is larger so that each ONU could get the uplink rate for230Mbit/s. What’s more, the increasing number of ONU won’t change the rate ofother ONU. Up to now, there is a wide spectrum of500nm LED light source beingprovided, we can get50ONUs with the uplink rate of230Mbit/s through this LEDsource. And the total uplink rate of slice scheme is about10times than TDM-PON,and about150to200times than DSL.The RSOA re-modulation scheme can achieve the rate of uplink1.25Gbit/s and downlink rate2.5Gbit/s by simulation with a good transmission quality without lightsource. In this scheme DWDM wavelength standard can be used. So this scheme cansupport more than80ONUs and each ONU can reach the bit rate of2.5Gbit/s and1.25Gbit/s. Obviously, the bit rate of this solution achieved is much faster thanTDM-PON and DSL.In the future, WDM-PON will play an important role in communicationtechnology. The schemes based on LED spectrum slicing and RSOA re-modulationmust be able to be an effective way to solve the access network "bottleneck"problem.