A first position (104) of the mobile client is determined at least in part by utilizing first signals received from at least one first signal source. The first signal source operates in a first location determination system (114). A second position (106) of at least one second signal source (120) is determined by utilizing both the determined first position of the mobile client and second signals received from the at least one second signal source (120). The second signal source (120) operates in a second location determination system. A third position (116) of the mobile client is determined utilizing the second signal source (120).