Energy-Efficient Long-Reach Passive Optical Network: A Network Planning Approach Based on User Behaviors

Long-reach passive optical network (LR-PON) is a cost-effective solution for providing broadband access spanning large areas. LR-PON extends the coverage span of PONs from the traditional 20 km range to 100 km and consolidates the multiple optical line terminals (OLTs) and central offices, thus reducing the operational cost and serving many more users. There are two type of LR-PONs: “tree-and-branch” and “ring-and-spur” LR-PON. To “green” the LR-PON and make it energy-efficient, we study a network planning approach based on user behaviors. By considering the different network usage behaviors of different kind of users (i.e., daily bandwidth demand profiles), we can assign users (e.g., business and residential users) efficiently to different wavelengths in “tree-and-branch” or “ring-and-spur” LR-PONs at networking planning stage and achieve high network utilization at all times. Heuristic searches can provide such assignments and their approximate solutions are very close to the lower bound. The behavior-aware user assignment achieves significant improvement over the traditional method in terms of used wavelengths and could thus saves the energy consumed by the LR-PON.