Methods and systems for providing geographic specific services to receivers in a satellite communications network via specific position location and information tagging schemes
Methods and systems for providing geographic specific services to receivers in a satellite communications network utilizes specific position location and information tagging to provide manual or automatic delivery of such services to the receivers.
1. A communications method comprising the steps:
continuously transmitting to a plurality of receivers in a target service area one or more data signals from a transmitters on a plurality of satellites deployed in a digital audio radio service network, said one or more data signals comprising a plurality of data channels, at least one of said data channels comprising at least one geographic specific information portion for locations in said target service area, said receivers having one or more probable locations in said target service area and having a constant or time-varying delay pattern for said one or more data signals;
receiving said data signals at said receivers;
continuously comparing said receivers' delay patterns for said one or more data signals with known delay patterns for a plurality of actual locations in said target service area that are delivered with said one or more data signals to said receiver;
determining said receivers' actual or probable locations in said target service area from said comparing step; and
selecting, in said receivers, and outputting from said receivers, said at least one geographic specific information portions for said locations.
2. The method of claim 1 further comprising selecting a plurality of reference points within said target service area, and determining, for each of said reference points, delay patterns for said one or more data signals from said transmitter to said plurality of reference points to determine a plurality of said known delay patterns.
3. The method of claim 1 or claim 2 further comprising determining the differential delay patterns from said transmitter to said reference points from one or more separate data signals transmitted over one or more different paths to said receivers.
4. The method of claim 3 further comprising, in said determining step, using identified positions of a receiver's nearest reference locations to determine the receiver's exact location by geometrical calculation.