A Smooth and Gradual Evolution to Next Generation PON Based on Simple Line-Coding

We propose a smooth and gradual evolution method to next generation passive optical network (PON) based on simple line-coding. At the beginning, a new OLT and some new ONUs are added into the existing PON without changing the existing ONUs. The evolution is gradual. The existing ONUs can be upgraded with demand. The coding is operated by software and requires no extra equipment. During different evolution stages, different line-codes are applied to reduce the crosstalk induced by the upgrade service to the existing service. The crosstalk is tested and shown not serious in the experiment.