From the characteristics of the indicated technologies and the calculations presented above it is clear that  FTTH technology is most demanding in terms of investment, yet provides significantly more options for increasing the speed of data flows in the future than FTTN technology,  FTTH technology is currently significantly cheaper to operate than FTTN technology,  Although FTTN technology is cheaper in terms of investment, it however suffers from capacity constraints and is significantly more expensive to operate than FTTH technology. Graph No 11 Percentage of coverage of Graph No 12 Percentage of coverage of dwellings with FTTH technologies dwellings with FTTN technologies depending on subsidy amount, MIT depending on subsidy amount, MIT When setting the necessary level of public support for investment, it was understood – in accordance with EU Guidelines – that subsidy funds will only be used for passive infrastructure, i.e. optical cables, switchboards, the construction parts of cabinets including electrical connections and residential wiring and all connected construction and installation work. From another perspective, these parts are usually assessed as long-term investments, whose lifespan as a rule exceeds ten and more years. The above presented two model cases used for the analysis concurrently assume that NGAs will be built using the synergy effects arising through the connection of neighbouring BSUs into larger units. Although the analysis is based on data about individual BSUs, the data derived from it cannot be used directly for the preparation of project investment plans for the individual areas. A more accurate calculation of costs, which can be used to prepare specific investment or project plans for a specific area, can only be prepared within the framework of the creation of project documentation for a specific territory, i.e. area of intervention. The models used in this document therefore do not anticipate which model will be selected by an aid applicant in its project. B. Used models for investment demands and conditions for return on investment for NGA projects The used model for investment demands and return on investment for NGA projects is composed of several modules: - An estimate of the costliness of construction of optical cables for both cabling variants for the BSUs, including the related costs for construction work. 46