A. Fixed Line Access Networks
 In fixed line access networks each subscriber (Subs) has a dedicated connection. Thus, the power per subscriber will be a stable metric. In DSL technologies the last node before the subscriber is the DSLAM (DSL Access Multiplexer). ADSL equipment consumes 1 – 2 W/Subs, VDSL equipment roughly consumes 3 – 5 W/Subs. VDSL equipment power consumption is slightly higher although trends indicate this technology is being optimized. 
Optical network equipment currently consumes 10 – 20 W per port. However, using GPON technology this can be further distributed. The OLT consumes 0.2 – 0.8 W/Subs. Due to the small range of VDSL technology, it is possible that VDSL equipment with a small number of connections are used. For example, for a VDSL DSLAM with 16 connections the power consumption of the optical backhaul will be 0.01 – 0.05 W/Subs. 
When evaluating the power consumption of these devices, one needs to consider that the premises where they are located often need to be cooled. Also measures are taken in order to prevent power failure. This overhead is expressed in Power Usage Effectiveness (PUE) that denotes the factor by which the equipment power consumption is to be multiplied in order to know the total power consumption (i.e. equipment + overhead). The PUE is typically a factor two. This means in reality the above mentioned numbers need to be doubled to estimate the full power consumption.