An electronic arrangement (106, 108, 300, 320) for positioning a mobile device, comprising - a modeling entity configured to, in order to construct a database for locating mobile devices, obtain positioning data and environment data from a plurality of measuring mobile devices present in an area of interest, and establish and maintain, based on the obtained data, a multi-level (202, 204, 206, 208) probability map model structure (201, 302) for the area of interest, wherein each higher level covers the area of interest with lower spatial resolution by a plurality of determined sub-areas (212, 214), each sub-area having a unitary character in terms of the obtained data and/or features derived therefrom, and each lower level correspondingly covers, for each said sub-area of the adjacent upper level, a plurality of determined sub-areas thereof with higher spatial resolution, the lowest level determining the highest spatial resolution location elements of the model, optionally coordinates, and - a locating entity configured to, in order to locate a mobile device, obtain at least environment data and optionally positioning data provided by the mobile device, and determine an estimate of the position of the mobile device by traversing through at least a portion of a number of vertical candidate paths of the multi-level probability map model structure starting from a number of candidate sub-areas in the highest level, the candidate sub-areas being selected and paths continued or terminated on each level based on determining the probability of the mobile device residing in each sub-area in view of the obtained environment data and optional positioning data and characteristics of the sub-area, until the lowest level with highest spatial resolution is reached, wherein the position estimate of the mobile device is determined based on the highest probability location elements thereof according to predefined criteria. - a modeling entity configured to, in order to construct a database for locating mobile devices, obtain positioning data and environment data from a plurality of measuring mobile devices present in an area of interest, and establish and maintain, based on the obtained data, a multi-level (202, 204, 206, 208) probability map model structure (201, 302) for the area of interest, wherein each higher level covers the area of interest with lower spatial resolution by a plurality of determined sub-areas (212, 214), each sub-area having a unitary character in terms of the obtained data and/or features derived therefrom, and each lower level correspondingly covers, for each said sub-area of the adjacent upper level, a plurality of determined sub-areas thereof with higher spatial resolution, the lowest level determining the highest spatial resolution location elements of the model, optionally coordinates, and - a locating entity configured to, in order to locate a mobile device, obtain at least environment data and optionally positioning data provided by the mobile device, and determine an estimate of the position of the mobile device by traversing through at least a portion of a number of vertical candidate paths of the multi-level probability map model structure starting from a number of candidate sub-areas in the highest level, the candidate sub-areas being selected and paths continued or terminated on each level based on determining the probability of the mobile device residing in each sub-area in view of the obtained environment data and optional positioning data and characteristics of the sub-area, until the lowest level with highest spatial resolution is reached, wherein the position estimate of the mobile device is determined based on the highest probability location elements thereof according to predefined criteria.