Modeling of a Plc Access Network

1 Abstract 2 INTRODUCTION Nowadays the access area has a big importance for the last mile network providers. One of the alternatives is the communication over power lines (PLC). The great advantage of PLC is that in every home and in every room there are sockets, which can be used for telecommunications, too. The big problem, however, is that the powerline network has been designed for electricity distribution and not for data transfer. Therefore , the characteristics of the powerline channel make it an unreliable transmission medium, dominated by distance and frequency dependent impulse noise from electrical machines and narrowband noise. In this paper we make our model at the call level to deene what is the innuence of the disturbances on the system capacity. We will consider the dependence of the blocking probability for voice connections, the utilization of the network and the average data rate on the channel outages because of erasures. Our investigations are concentrated on the PLC access area (also referred to as last mile). It connects the backbone communication network with the customer's electrical feeding point (meter). Normally, the transformer station is used as a connection point between the communication backbone network and the low voltage distribution network. The transmission system consists of one base station, situated in the transformer substation and a number of subscriber station (access units), interconnected with each other and with the base station via the power-line medium, see g.1. The part of the PLC network, where the access units have the same transmission conditions and receive the same information from the base station we deene as a branch. Every branch has a 1