The invention relates to an access network for exchanging communication signals between a transit network and at least one communication medium of a user. The communication medium is operatively connected to an exchange by means of an optical fiber connection for exchanging the communication signals, and the exchange is connected to the transit network. The fiber connection comprises at least one multimode fiber, which is bent over at least one first part of its length, in such a manner that the fiber comprises at least one complete winding in the first part thereof mainly for maintaining one or more modes of the communication signals into the fiber. Said modes have been selected from a group comprising the ground mode and one or more lower modes near the ground mode.