A Techno-Economic Model for the Optimized Introduction of ADSL Technology in an Urban Area

摘要

This paper optimizes the introduction of broadband internet service in an existing PSTN network, by the means of a techno-economical model. The proposed model determines the optimal timing of introduction of ADSL technology to an urban telephone network, as seen by the Network Access Provider perspective. The implementation strategy is determined on the basis of the maximization of the total income while keeping capital expenditures under a given budget. Costs and Incomes are predicted based on current prices of both charging rates and broadband equipment. The feasible policies concern the evolution of the Central Offices of the urban network, as well as the introduction of centralized equipment, such as routers and aggregators. The model first determines the number of feasible policies and the costs associated with each one, using inputs concerning the network status, i.e., the number, position and capacity of exchanges and links, broadband services demand predictions, technical specifications as well as pricing predictions and, by the means of a charging (revenues) model produces the alternative policies for each Central Office (CO) as well as for the introduction of routers and aggregators along with their corresponding costs and incomes. These results are then fed to the second part of the model, which, using the costs and revenues associated with each alternative policy for each CO and for each type of centralized equipment, selects the overall optimal network policy, by estimating the most profitable combination of CO policies, one for each, as well as the policies concerning the introduction of routers and aggregators, by keeping the sum of the corresponding costs under certain limits. The overall policy is determined by the means of an IP (Integer Programming) algorithm. The Integer Programming algorithm consists of an objective function maximized with respect to a number of constraints. The model was implemented in the case of the urban telephone network of Patras/Greece, using several realistic assumptions for the estimation of the costs and revenues, as well as typical current configurations for estimating the costs involved. The results obtained proved the validity of the model.