Design of WDM PON With Tunable Lasers: The Upstream Scenario

Tunable lasers are potential upstream optical light generators for wavelength-division-multiplexing (WDM) passive optical network (PON), which is a promising solution for next-generation broad-band optical access. The wavelength provisioning flexibility of tunable lasers can increase the admissible traffic in the network as compared to wavelength-specific lasers. Generally, the broader the lasers' tuning ranges, the more the traffic can be admitted to the network. However, broad tuning range requires sophisticated technology, and probably high cost. To achieve the optimal tradeoff between the admissible traffic and the cost, we investigate the relationship between lasers' tuning ranges and the network's admissible traffic and then design WDM PON by selecting lasers with proper tuning ranges for the upstream data transmission. Specifically, we focus on addressing two issues under three scenarios. The two issues are: how to admit the largest traffic by properly selecting lasers, and how to admit given upstream traffic using lasers with tuning ranges as narrow as possible. The three scenarios are: full-range tunable and wavelength-specific lasers are available, limited-range tunable lasers are available, and the exact number of lasers with specific tuning ranges are given.