Path discovery method for return link communications between a mobile platform and a base station

• US 20020168971A1
• Filed: 05/08/2001
• Published: 11/14/2002
• Est. Priority Date: 05/08/2001
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Parkman, David S.
• Granted Patent: US 6,778,825 B2
• Time in Patent Office: Days
• US Class Current: 455/427
• CPC Class Codes: H04B 7/18508 with satellite system used as relay, i.e. aeronautical mobile satellite service

Abstract

A polling system and method for establishing forward and return communications links with a plurality of mobile platforms operating within a given coverage region. The system and method combines preliminary return channel information and path discovery information into polling messages transmitted by a ground station. A mobile platform responding to the polling messages relayed from one of a plurality of satellite based transponders transmits a response on the designated preliminary return channel and includes the path discovery information in its response. The path discovery information informs the ground station of the precise route through various components of the forward link communications path that the polling message took in reaching the mobile platform. Combining the path discovery information and the return channel information into the forward link polling messages saves important transponder bandwidth.

Claims

1. A method for establishing a radio frequency (RF) return communications link from a mobile platform having an RF transceiver to a base station having an RF transceiver, via at least one space based RF transponder, and wherein an operations center coordinates the transmission of RF messages from said base station to said mobile platform, the method comprising the steps of:

a) transmitting a message to said mobile platform from said base station via said space based RF transponder, said message including information relating to a transmission path discovery through specific components associated with said operations center;

b) causing said RF transceiver of said mobile platform to receive said message; and

c) causing said RF transceiver of said mobile platform to transmit a response to said base station via said space based RF transponder which includes said transmission path discovery information, thereby informing said ground station of the precise route through said specific components that said message took in passing from said operations center to said mobile platform.

2. The method of claim 1, further comprising the step of:

placing said discovery path information in a message body of said message.

3. The method of claim 1, further comprising the steps of:

using a plurality of forward link modulators associated with said operations center to transmit a plurality of said messages; and

including information in said transmission path discovery information of each said message as to specify which one of said forward link modulators generated said message.

4. A method for establishing a radio frequency (RF) return communications (ink from a mobile platform having an RF transceiver to a base station having an RF transceiver, via at least one space based RF transponder, and wherein an operations center coordinates the transmission of RF messages from said base station to said mobile platform, the method comprising the steps of:

a) transmitting a message to said mobile platform from said base station via said space based RF transponder, said message including a message body, said message body including information relating to a transmission path discovery through specific components of at least one of said operations center or said space based RF transponder;

b) causing said RF transceiver of said mobile platform to receive said message; and

c) causing said RF transceiver of said mobile platform to transmit a response to said base station via said space based RF transponder which includes said transmission path discovery information, thereby informing said ground station of the precise route through said specific components of at least one of said operations center components or said space based RF transponder, that said message took in reaching said mobile platform.

5. The method of claim 4, further comprising the steps of:

a) providing that said specific components include a plurality of independent forward link modulators associated with said operations center, for transmitting a plurality of said messages therefrom; and

b) including information in said path discovery information associated with each said message transmitted from said ground station, as to specifically which one of said forward link modulators generated a specific one of said messages received by said RF transceiver of said mobile platform.

6. The method of claim 4, further comprising the step of:

a) providing that said RF transceiver of said mobile platform includes a plurality of channels for receiving RF messages; and

b) causing said RF transceiver of said mobile platform to include in said response information identifying exactly which said channel said path discovery information was received on.

7. A method for establishing a radio frequency (RF) return communications link from a mobile platform having an RF transceiver to a base station having an RF transceiver, via at least one of a plurality of space based RF transponders, and wherein an operations center having a plurality of independent forward link modulators coordinates the transmission of RF messages from said base station to said mobile platform, the method comprising the steps of:

a) transmitting a message to said mobile platform from said base station via said space based RF transponder, said message including a message body, said message body including information relating to a transmission path discovery, wherein said transmission path discovery information includes which specific one of said forward link transponders and which specific one of said space based RF transponders said message was routed through while being transmitted to said mobile platform;

b) causing said RF transceiver of said mobile platform to receive said message; and

c) causing said RF transceiver of said mobile platform to transmit a response to said base station via said space based RF transponder which includes said transmission path discovery information, thereby informing said ground station of the precise route of said message in reaching said mobile platform.

8. The method of claim 7, further comprising the step of:

a) providing said RF transceiver of said mobile platform with a plurality of independent receiving channels; and

b) causing said RF transceiver of said mobile platform to include in its said response information as to which one of its said channels said message was received on.

9. A method for establishing a radio frequency (RF) return communications link from a mobile platform having an RF transceiver to a base station having an RF transceiver including a plurality of independent receiving channels, via at least one of a plurality of space based RF transponders, and wherein an operations center having a plurality of independent forward link modulators coordinates the transmission of RF messages from said base station to said mobile platform, the method comprising the steps of:

a) transmitting a plurality of messages to said mobile platform from said base station via said space based RF transponder, each said message including a message body, said message body including information relating to a transmission path discovery of its associated said message, wherein said transmission path discovery information includes which specific one of said forward link transponders and which specific one of said space based RF transponders said message was routed through while being transmitted to said mobile platform;

b) causing said RF transceiver of said mobile platform to receive at least one of said messages;

c) causing said RF transceiver of said mobile platform to transmit a response to said base station via said space based RF transponder which includes said transmission path discovery information associated with said message which it received, thereby informing said ground station of the precise route of said received message in reaching said mobile platform; and

d) further including in said response information identifying specifically which one of said channels of said RF transceiver of said mobile platform said received message was received on.