Fig. 1
From: Skills, earnings, and employment: exploring causality in the estimation of returns to skills
Source: Falck et al. (2016)
The Structure of a DSL Network. The figure shows the structure of a DSL network that relies on the “last mile” of the preexisting fixed-line voice-telephony network. The “last mile” consists of copper wires connecting every household via the street cabinet to the main distribution frame (MDF). At the MDF, a DSLAM (Digital Subscriber Line Access Multiplexer) is installed that aggregates and redirects the voice and data traffic to the telecommunication operator’s backbone network.