Energy consumption of telecommunication access networks

7 Consolidation and conclusion This survey compares the power consumption of four broadband access technologies based on a 100%of homes connected rollout within an existingmodel region. Themodel region consists of sixmunicipalities with a population of 56,700 and 25,311 possible subscribers. The access technologies are: • VDSL2-Vectoring • HFC with DOCSIS 3.0 • FTTH – Point-to-Point • FTTH – GPON The energy consumption was estimated by identifying the needed active components. Therefore, a spatial analysis of themodel region and the obtained information on existing infrastructure was conducted, which led to the respective number of active components for each access technology. The figures on the power consumption of the different active components aremeasured figures fromnetwork operators and information fromdifferent equipment manufacturers. As Figure 30 shows, the access technologies differ considerably in the number of required active network elements and locations. The HFC network with its 794 fibre nodes and 12 CMTS needs themost active network elements. Followed by VDSL2 Vectoring with 538 active street cabinets (DSLAMs) and six central offices. FTTH has with its 36 PoPs by far the lowest amount of active network elements in different locations. This is also reflected in the power consumption of the access networks. The power consumption of the HFC and VDSL2 Vectoring access networks is 1.8 to 2.2 times the power of the FTTH – Point-to-Point and up to approximately 7.5 times more than the FTTH – GPON access network. Expressed in figures, the HFC access network requires 114 kW, the VDSL2 Vectoring access network 142 kW, the FTTH – Point-to-Point access network 64 kWand the FTTH – GPON access network 19 kW. VDSL2-Vectoring HFC FTTH – PtP FTTH – GPON Active network elements in the access network 538 street cabinets + 6 central offices 794 fibre nodes + 12 CMTS 36 PoPs 36 PoPs Power consumption access network [kW] 142 114 64 19 Power consumption CPE [kW] 253 456 341 341 Total power consumption [kW] 396 569 406 360 Total energy consumption [MWh/year] 3,465 4,987 3,557 3,156 Figure 30: Comparison of the number of active network elements and the power consumption of the examined access technologies. For the customer premises equipment it is somewhat different. Here the HFC network is placed last with 456 kW, the FTTH networks second with 341 kW and the VDSL2 Vectoring network is first with 253 kW. This is because an additional user device (house amplifier or ONT) is used for the HFC and the FTTH networks. Especially for the FTTH networks, the energy consumption could be reduced by optimizing the customer premises equipment. Therefore, the total power consumption of access network and customer premises equipment differs not much between the VDSL2 Vectoring and the FTTH – Point-to-Point network – 396 kW for VDSL2 Vectoring and 406 kW for FTTH – Point-to-Point. The lowest power consumption has the FTTH – GPON network with 360 kW. The HFC network on the other hand has a by far bigger power consumption – 569 kW. 28