Mobile positioning is a technology used by telecommunication companies to approximate where a mobile phone, and thereby also its user, temporaily resides. More properly segregated the term applies more to a locating process rather than a positioning process. Such service is offered as an option of the class of location-based services (LBS). The technology is based around the fact that a roaming mobile phone always communicates wirelessly with one of the closest base stations, so if you know which base station the phone communicates with, you know that the phone is close to the respective base station. Advanced systems determine the sector in which the mobile phone resides and roughly estimate also the distance to the base station. Further approximation can be done by interpolating signals between neighbouring base stations. Qualified services can obtain a precision of down to 50 meters in urban areas where mobile traffic and density of base stations is sufficiently high. Rural and desolate areas may see miles between base stations and therefore determine locations less precisely.