Described is a navigation solution calculation method and a user device. The method can include providing an assistance request to a server. One or more signal path signatures can be received from the server. The one or more signal path signatures can be associated with a first position of the user device. The one or more signal path signatures can be compared with one or more satellite signals received by the user device from one or more satellites. A second position of the user device can be determined based on the comparison.