SUCCESS-LCO: instant and cost-effective upgrade of existing passive optical networks by spectral shaping line codes

Novel line codes combined with WDM techniques allow simple and cost-effective overlay of higher bitrate services in existing fiber optical access networks. The solution leaves the existing services and field-deployed fibers untouched. The design of the spectral shaping line codes is presented, along with the analyses for different code rates and processing window sizes. The computation can be simplified by employing vector quantization for the trigonometric functions. DC balance is achieved by forwarding the DC residual to the following window. The spectral shape can be manipulated in various ways to optimize the system performance. Experiments have been conducted to demonstrate and compare several different optimized line codes. For a specific tolerable interference level, the optimal line code can easily be determined which maximizes the data throughput. The service overlay by the line coding technique provides a very flexible and economic way to upgrade existing passive optical networks.