  scope as to enable a guarantee of meeting the conditions for the recognition of the network as an NGA according to the parameters specified in this document, data40 obtained through the data collection by the CTO from January to the end of March 2016 and submitted after verification on 31 May 2016 with fixation as of 25 May 2016 were used, data and information submitted by enterprises under trade secrets were used. The model BSU consists of blocks of flats and family houses, as shown in the following image No 3. It is true, however, almost without exception, that single-dwelling developments predominate in white areas, often scattered over a fairly large area or over difficult terrain. In such cases a public aid solution is appropriate because it will help to accelerate the return on the enterprises’ investments. Image No 3 Model BSUs It should be noted that the financial analysis considered the FTTH and FTTN technologies as these are the most expensive technologies in terms of investment costs and most demanding in term of return on investment. As the financial analysis also needed to demonstrate that the constructed NGA networks could be managed sustainably, cheaper technologies needn’t be addressed. Due to the outlook for the need for speeds of 100 Mbit/s, respectively 1 Gbit/s and higher, it is from today’s perspective unrealistic to consider - for backhaul electronic communications networks - any other than primarily optical technologies. For electronic communications connections (“connections”) this analysis focused - for the reasons given below - on FTTH, FTTB, FTTN and FTTCab technologies (for an explanation of these terms see Annex 7 explanation of terms and abbreviations). 40 These data are trade secrets and it is difficult to publicly manipulate them even in aggregated form, and so the sector was not invited to these calculations. However, comments from enterprises operating in electronic communications were fully used during the calculation and analysis. 44