| 摘要 |
<p>Latitude and longitude information within a wireless navigation and information system (200) is transmitted from route planning equipment (207) to a base site (201). A translator (203) converts each reference point from an absolute coordinate to a relative coordinate by subtracting a reference geographic location from each absolute coordinate (350). The base site (201) then sends a message comprising the relative coordinates for each reference point to the remote unit (213). Finally, the remote unit (213) utilizes the reference geographic location and calculates absolute coordinates for each reference point and passes this information to any navigation equipment (705) that is coupled to the remote unit (213). Broadcasting only the relative coordinates of each reference point to the remote unit (213) allows reference points to be transmitted to the remote unit (213) in a shorter length message than with prior-art methods.</p> |
