In order to provide sufficient bandwidth, the networks shall be migrated to fiber optics. The specific question for the study presented is how the different degrees of freedom to migrate the access networks in Austria to FTTH affect their ecological footprint in the years 2024 to 2050.
The study considers the extent of complete fiber-optic roll-out, its roll-out speed and the speed and extent of migration from the existing old networks (copper pairs, DOCSIS, mobile phone cubes) to the new FTTH network.
A new generic bottom-up model has been developed, based on the settlement stucture in Austria, starting the migration consideration with the current state of the access network deployment. It maps the further network development in the context of the options of expansion, the assumed migration model and the shutdown scenarios and, depending on network infrastructure availability and use, determines the required facilities and network elements, including trench construction. The CO₂ emissions generated by the construction of trenches und network components and by the operation of the network elements as a function of energy consumption are calculated on an annual basis. Energy consumption is determined for each network technology and network element; this scales with the number of connections and bandwidths.
The results prove:
- Of the existing technologies, FTTH is the most emission-efficient. All fixed access network technologies that involve transmission via copper pairs or coaxial cables, or via radio links, are less emissions-efficient.
- An early and rapid fiber-optic deployment is more emission-efficient than a later roll-out, despite the deployment emissions released earlier, because the savings achieved in the old technologies start earlier , too, comparing it as a cumulative result.
- This effect is further intensified if the efficiency of fiber optic transmission in the access network increases.
- A high increase in emission savings results if there are no remaining copper and radio connections (HFC, FTTB, hybrid and pure cubes) left, i.e. all connections are migrated to FTTH