The present disclosure provides devices, systems, and methods to utilize relative timing offset information reported by one or more mobile devices. When coupled with AGPS information reported by one or more mobile devices, the offset information is be used to calibrate calculations and subsequently to locate all 3G mobiles with GPS-like accuracy, whether or not a GPS receiver is available on said mobile device being located. A determination of a propagation delay between one or more cell sites and a mobile device is reported to a network and used to calibrate unknown information such as a timing offset, to improve the accuracy of a detected location. The relative timing offset can be applied to determine a location for all other mobile devices within the area served by the known base station. The present disclosure utilizes this method in conjunction with information crowd-sourced from a plurality of mobile devices.