Patent ID: 8150378
Filing Date: 2012-04-03
Classification: G01S,H04W

Abstract:
1. A method for determining a position of a node, the method comprising: receiving first position data at the node from a first reference node and second position data from a second reference node, wherein the second position data comprises second position measurement information and a precision indicator which indicates accuracy of the second position measurement information; generating a timestamp at the node which indicates when the second position data was received by node, associating the timestamp with the second position data and storing the second position data and associated timestamp at the node; receiving updated first position data at the node from the first reference node; determining, at the node, whether updated second position data has been received from the second reference node; generating, at the node when the node determines that it has not received updated second position data from the second reference node, aged second position data by decreasing the precision indicator of the stored second position data as a function of an amount of time that has passed since a time indicated by the associated timestamp; and determining a position of the node using both the aged second position data and the updated first position data.