Expand or Oversize? Planning Internet Access Network in a Demand Growth Scenario

Internet network design specialists are looking for technologies and strategies to deliver network service under increased demand conditions. The choice of strategies is based on applying optimization and decision-making methods to select the most appropriate cable network design considering criteria established by the problem definition. However, this definition is itself a decision problem that has not received analysis in the literature. In particular, one of the most important questions is the necessity to define an expansion strategy. The first alternative (expansion) is to design a network to serve consumers with Internet demand equal to or greater than the predefined one to expand the network annually to serve consumers that reach the predefined Internet speed. The second alternative (oversizing) is to design a network to serve consumers with future Internet demand (after 5 years) at or above that the predefined one. Considering this, the objective of this research is to define the most advantageous strategy of expansion planning to attend a 5 years forecasted Internet demand, considering: (1) the possibility of utilizing a Gigabit-capable Passive Optical Network technology; (2) the application of the minimal Steiner tree and Dijkstra algorithms in planning procedures; (3) the influence of economic and technological factors on the demand forecast; (4) the aggressive, moderate, and conservative scenarios in decision-making. The results show that the over-dimensioning strategy reduces network investment by between 30 and 41%, but that this reduction does not always lead to a market investment ratio higher than that observed in the expansion strategy.