In an embodiment of the invention, the downlink comprises one or more segments such as illustrated by segments 111A, 111B, 111C, and 111D shown in FIG. 1, the aggregate transmission time as the client's request travels from one component of the navigation system shown in FIG. 1 to the next via segments 111A, 111B, 111C, and 111D is the downlink delay in an embodiment of the present invention.