“…Although in each case, the optimization objective varies, two general approaches can be distinguished. In the first one, the goal is to minimize the expected error of the positioning estimation (Baala et al, 2009, Sharma et al, 2010, He et al, 2011, Ficco et al, 2013, Li et al, 2015, Laitinen , Lohan, 2016, Voronov, 2017. However, it can be argued that making an accurate prediction of the error of a positioning estimation is quite challenging due to the complexity of properly modelling the error's sources themselves.…”