Marta Garcia Arranz, Klaus D. Hackbarth unter Mitarbeit von Bernd Ickenroth
Kosten von vermittelten Leitungen in digitalen Netzen
Nr. 169 / Dezember 1996
The liberalisation process and concurrent technical progress lead to increasing competitive pressure on the telecommunications markets. Established and also new suppliers are under increasing pressure to fix tariffs for their services in a cost-oriented manner. This can only be achieved if the supplier is in a position to determine the costs of a service as exactly as possible. At the same time, the calculation of costs of individual network elements, or of special services offered on the basis of these elements, by the network operators is essential information for the regulator in order to judge whether end-user tariffs and interconnection fees are in accordance with criteria of efficient provision of services as they are e.g. laid down in the new German Telecommunications Law.
In this study a method will be presented by which unit costs per erlang can be determined as a basis for fixing tariffs for telephone connections. The starting point are investment costs for 64 kbit/s narrow-band transmission lines. It is from these investment costs that the annual costs are calculated which in turn are the basis for the corresponding unit costs under the assumption of different traffic utilizations per line.
The methodical formulation is based on a functional and topological factorization of the network and a thereby achieved classification of narrow-band transmission lines in different types of connections which are made up of a reduced number of reference connections. The costs per type of connection result from the addition of costs of the associated reference connections and the costs of the connecting interfaces. Aspects of network design are included and the extent of utilization of the network through the definition of parameters and ranges of values that these parameters can take on. Through the variation of the parameter values within the given ranges the effect of these network parameters on the unit costs per erlang are examined.