Patent ID: 6748202
Filing Date: 2004-06-08
Classification: H04W

Abstract:
An apparatus (10), comprising:a) a cellular module (11), responsive to a portion of a downlink frame signal conveying a cellular frame provided by a cellular communication system; and b) a main module (12), responsive to ranging signals from beacons (27) of a positioning system in which time is kept according to a predetermined time reference; the apparatus characterized in that: the cellular module (11) provides a trigger signal indicating the arrival of the portion of the downlink frame signal, and is further responsive to a signal indicating information for relating the instant at which the trigger signal is provided to a time value according to the predetermined time reference; and the main module (12) provides the signal indicating the information for relating the instant at which the trigger signal is provided by the cellular module (11) to a time value according to the predetermined time reference; wherein the trigger signal is provided over a connection (29) between the cellular module (11) and the main module (12) so constructed that any delay between sending and receiving the trigger signal is either negligible or can be determined.