Satellite trunked radio service system

• US 5,717,830 A
• Filed: 05/29/1996
• Issued: 02/10/1998
• Est. Priority Date: 09/19/1995
• Status: Expired due to Fees

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: Amsc Subsidiary Corp. (PetIQ, Inc.)
• Inventors: Sigler, C. Edward, Sweet, Richard S.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): LE, THANH C
• Application Number:
  US08/657,479
• Time in Patent Office: 622 Days
• Field of Search: 455/12.1, 455/13.1, 455/13.2, 455/403, 455/410, 455/411, 455/422, 455/424, 455/425, 455/426, 455/427, 455/428, 455/429, 455/430, 455/517, 455/518, 455/519, 455/524 , 455/525, 455/62, 455/63, 455/67.1, 380/20, 380/23, 380/49, 370/316, 370/321, 370/327, 370/329, 370/330
• US Class Current: 455/426.1
• CPC Class Codes: H04B 7/18567 Arrangements for providing additional services to the basic mobile satellite telephony service
• CPC Class Codes: H04B 7/18578 Satellite systems for providing broadband data service to individual earth stations for selecting H04W; provisions for broadband connection, H04Q11/0478

Abstract

In a mobile communication system, a system for providing communication between multiple users in a closed user group arrangement includes first and second mobile earth terminals (METs) registering with the mobile satellite system. The first MET selects a closed user group network identifier (NET ID) representing a NET group to establish voice communication therewith and transmits the NET ID to a central controller. The central controller receives the NET ID from the first MET, validates the first MET for communication, validates the NET ID, allocates a frequency for the NET group, and broadcasts the message to the NET group informing the NET group of the allocated frequency. The second MET tunes to the frequency in response, to the message broadcast by the central controller. The closed user group arrangement provides security measures to ensure only authorized METs gain access to the NET group, dual standby mode of operation, and priority default operation.

Claims

1. In a mobile communication system including a communication switching office having an antenna for receiving/transmitting a message from/to a vehicle using a mobile communication system, a central controller receiving/transmitting the message from/to the communication switching office issued from the vehicle, a method of providing communication between multiple users in a closed user group arrangement, said method comprising the steps of:

(a) first and second mobile earth terminals (METs) registering with the mobile communication system;

(b) the first MET selecting a closed user group network identifier (NET ID) representing a NET group including the first and second METs to establish voice communication therewith;

(c) the first MET transmitting the NET ID to the central controller;

(d) the central controller receiving the NET ID, validating the first MET for communication, validating the NET ID, allocating a frequency for the NET group, and broadcasting the message to the NET group including the second MET informing the NET group of the allocated frequency and the voice communication associated therewith; and

(e) the second MET tuning to the frequency in response to the message broadcast by the central controller,

wherein the first MET including a priority default operation, and said priority default operation comprising the steps of;

(1) assigning, by the first MET, a default priority NET group for receiving a priority message when a priority button of the first MET is activated;

(2) activating, by the first MET, the priority button of the first MET to initiate the priority message to be transmitted to the default priority NET group even when the first MET is active in the NET group, wherein the default priority NET group is different than the NET group;

(3) tuning, by the first MET, to a GC-S channel and transmitting a Net Radio Access Request Signalling Unit (NRACRSU) with a priority code appended on a corresponding receive channel indicating the default priority NET group;

(4) receiving, by the central controller, the NRACRSU and performing a MET originated NET Radio call setup procedure;

(5) rebroadcasting by the central controller the NET Radio Channel Assignment (NRCHASU) on the GC-S channel identified in the Net ID or that are active;

(6) transmitting by the central controller the NRCHASU a predetermined number of times in a predetermined number of consecutive superframes for a NET Radio channel assignment;

(7) setting by the central controller, the priority code and including a call identifier in the GC-I channel assignment message;

(8) tuning, by the first MET, to the NET Radio channel assignment and proceeding with the voice communication.

2. The method according to claim 1, wherein when the Net ID selected for the priority default operation is in use and a speaker identifier is not vacant, said method further comprises the step of detecting, by the first MET having a directory number, that the speaker identifier no longer matches the directory number, and stopping the transmission in accordance with call monitoring procedures.

3. The method according to claim 1, wherein the central controller controls the closed user group satellite communication including net radio parameters used by the first and second METs.

4. The method according to claim 1, wherein the central controller selectively downloads the NET IDs to the first and second METs according to predetermined user criteria.

5. The method according to claim 4, wherein the central controller collects billing information regarding the closed user group satellite communication and transmits the billing information to the mobile satellite system, and wherein the mobile satellite system charges a service fee to a customer that has requested the closed user group arrangement.

6. The method according to claim 1, further comprising the steps of:

(A1) a non-MET accessing the mobile satellite system via one of a public switched telephone network and a cellular network to initiate a closed user group communication with the NET group including at least one of the first and second METs;

(A2) the central controller broadcasting the message to the NET group informing the NET group of the allocated frequency and the voice communication associated therewith; and

(A3) the at least one of the first and second METs tuning to the frequency in response to the message broadcast by the central controller to communicate with the non-MET in the closed user group arrangement.

7. The method according to claim 1, further comprising the steps of:

(A1) the first MET selecting the closed user group network identifier (NET ID) representing a NET group including the first MET and a non-MET serviced by one of a public switched telephone network and a cellular network to establish voice communication therewith;

(A2) the first MET transmitting the NET ID to the central controller;

(A3) the central controller receiving the NET ID, determining that the NET group includes the non-MET, and broadcasting a non-MET message to the one of the public switched telephone network and the cellular network including the voice communication associated therewith; and

(A4) the one of the public switched telephone network and the cellular network receiving the non-MET message from the central controller and transmitting the non-MET message to the non-MET to establish the closed user group arrangement between the MET and the non-MET.

8. The method according to claim 1, wherein the first MET includes a push to talk (PTT) device for generating the release of speaker message, and wherein said method further comprises the steps of the first MET activating the PTT device generating a PTT signal only when the PTT device is activated after the current speaker is one of vacant or the first MET, relieving congestion on the satellite by selectively transmitting the PTT signal.

9. The method according to claim 1, wherein when the first MET activates the PTT device before one of the current speaker is vacant and the first MET, the first MET ignores the activation of the PTT device.

10. The method according to claim 1, further comprising the step of the central controller selectively downloading monitor codes to the first and second METs according to predetermined user criteria.

11. The method according to claim 10, wherein the monitor codes functioning to lock at least one of the first and second METs to the NET group preventing the NET group from being released when no request has been made by one of the first and second METs to be the current speaker after the predetermined period of time.

12. In a mobile communication system including a communication switching office having an antenna for receiving/transmitting a message from/to a vehicle using a mobile communication system, a central controller receiving/transmitting the message from/to the communication switching office issued from the vehicle, a method of providing access to a closed user group voice communication for a mobile communication system storing a first security key, said method comprising the steps of:

(a) first and second mobile earth terminals (METs) registering with the mobile communication system;

(b) the first MET selecting a closed user group network identifier (NET ID) representing a NET group including the first and second METs to establish voice communication therewith;

(c) the first MET transmitting the NET ID to the central controller;

(d) the central controller receiving the NET ID, validating the first MET for communication, validating the NET ID, allocating a frequency for the NET group, and broadcasting the message to the NET group including the second MET informing the NET group of the allocated frequency and the voice communication associated therewith; and

(e) the second MET generating a scrambling vector for access to the voice communication, the scrambling vector being generated in accordance with the following steps;

(e1) generating a second security key having first and second components using a first process having first and second input signals, the first input signal comprising the first security key and the second input signal comprising at least one of a transmit frequency and a receive frequency;

(e2) generating the scrambling vector responsive to the second security key; and

(f) the second MET tuning to the allocated frequency for the NET group using the scrambling vector to gain access thereto.

13. A method according to claim 12, wherein the first process comprises a data encryption algorithm.

14. A method according to claim 13, wherein the data encryption algorithm comprises the DES encryption algorithm.

15. A method according to claim 12, wherein the at least one of the transmit frequency and the receive frequency comprises both the transmit and receive frequencies.

16. A method according to claim 12, wherein the second input signal further comprises fill bits received from a communication bulletin board in the mobile communication network system.

17. In a mobile communication system including a communication switching office having an antenna for receiving/transmitting a message from/to a vehicle using a mobile communication system, a central controller receiving/transmitting the message from/to the communication switching office issued from the vehicle, a method of providing communication between mobile earth terminals (METs), said method comprising the steps of:

(1) providing dual standby operation permitting voice communication alternately between a closed user group arrangement (NET radio) and a mobile telephone service (MTS);

(2) responding, by the MET, either to a MTS page request indicating the mobile telephone service is being requested or to a NET radio channel assignment request as transmitted on a GC-S channel, wherein while the MET is responding to a service request of one of the closed user group arrangement and a mobile telephone service, the MET is not required to monitor the GC-S channel for service requests of another of the closed user group arrangement and a mobile telephone service,

wherein the closed user group arrangement is implemented according to the steps of;

(a) first and second mobile earth terminals (METs) registering with the mobile communication system;

(b) the first MET selecting a closed user group network identifier (NET ID) representing a group including the first and second METs to establish voice communication therewith;

(c) the first MET transmitting the NET ID to the central controller;

(d) the central controller receiving the NET ID, validating the first MET for communication, validating the NET ID, allocating a frequency for the group, and broadcasting the message to the group including the second MET informing the group of the allocated frequency and the voice communication associated therewith; and

(e) the second MET tuning to the frequency in response to the message broadcast by the central controller.

18. The method according to claim 17, wherein the central controller controls the closed user group satellite communication including net radio parameters used by the first and second METs.

19. The method according to claim 17, wherein the central controller selectively downloads the NET IDs to the first and second METs according to predetermined user criteria.

20. The method according to claim 17, wherein the central controller collects billing information regarding the closed user group satellite communication and transmits the billing information to the mobile satellite system, and wherein the mobile satellite system charges a service fee to a customer that has requested the closed user group arrangement.

21. The method according to claim 17, further comprising the steps of:

(A1) a non-MET accessing the mobile satellite system via one of a public switched telephone network and a cellular network to initiate a closed user group communication with the NET group including at least one of the first and second METs;

(A2) the central controller broadcasting the message to the NET group informing the NET group of the allocated frequency and the voice communication associated therewith; and

(A3) the at least one of the first and second METs tuning to the frequency in response to the message broadcast by the central controller to communicate with the non-MET in the closed user group arrangement.

22. The method according to claim 17, further comprising the steps of:

(A1) the first MET selecting the closed user group network identifier (NET ID) representing a NET group including the first MET and a non-MET serviced by one of a public switched telephone network and a cellular network to establish voice communication therewith;

(A2) the first MET transmitting the NET ID to the central controller;

(A3) the central controller receiving the NET ID, determining that the NET group includes the non-MET, and broadcasting a non-MET message to the one of the public switched telephone network and the cellular network including the voice communication associated therewith; and

(A4) the one of the public switched telephone network and the cellular network receiving the non-MET message from the central controller and transmitting the non-MET message to the non-MET to establish the closed user group arrangement between the MET and the non-MET.

23. The method according to claim 17, wherein the first MET includes a push to talk (PTT) device for generating the release of speaker message, and wherein said method further comprises the steps of the first MET activating the PTT device generating a PTT signal only when the PTT device is activated after the current speaker is one of vacant or the first MET, relieving congestion on the satellite by selectively transmitting the PTT signal.

24. The method according to claim 17, wherein when the first MET activates the PTT device before one of the current speaker is vacant and the first MET, the first MET ignores the activation of the PTT device.

25. The method according to claim 17, further comprising the step of the central controller selectively downloading monitor codes to the first and second METs according to predetermined user criteria.

26. The method according to claim 25, wherein the monitor codes functioning to lock at least one of the first and second METs to the NET group preventing the NET group from being released when no request has been made by one of the first and second METs to be the current speaker after the predetermined period of time.

27. In a mobile satellite system including a satellite communication switching office having a satellite antenna for receiving/transmitting a satellite message via a satellite from/to a vehicle using a mobile communication system, a central controller receiving/transmitting the satellite message from/to the satellite communication switching office issued from the vehicle via the satellite, a system for providing satellite communication between multiple users in a closed user group arrangement, comprising:

first and second mobile earth terminals (METs) responsively connected to and registering with the mobile satellite system, the first MET selecting a closed user group network identifier (NET ID) representing a NET group including the first and second METs to establish voice communication therewith and transmitting the NET ID; and

a central controller responsively connected to the first and second METs, the central controller receiving the NET ID from the first MET, validating the first MET for communication, validating the NET ID, allocating a frequency for the NET group, and broadcasting the message to the NET group including the second MET informing the NET group of the allocated frequency and the voice communication associated therewith, the second MET tuning to the frequency in response to the message broadcast by the central controller, and the central controller assigning the first MET as current speaker for the NET group,

wherein the first MET including a priority default operation, and said first MET and said central controller implementing the following operations;

(1) assigning, by the first MET, a default priority NET group for receiving a priority message when a priority button of the first MET is activated;

(2) activating, by the first MET, the priority button of the first MET to initiate the priority message to be transmitted to the default priority NET group even when the first MET is active in the NET group, wherein the default priority NET group is potentially different than the NET group;

(3) tuning, by the first MET, to a GC-S channel and transmitting a Net Radio Access Request Signalling Unit (NRACRSU) with a priority code appended on a corresponding receive channel indicating the default priority NET group;

(4) receiving, by the central controller, the NRACRSU and performing a MET originated NET Radio call setup procedure;

(5) rebroadcasting by the central controller the NET Radio Channel Assignment (NRCHASU) on the GC-S channel identified in the Net ID or that are active;

(6) transmitting by the central controller the NRCHASU a predetermined number of times in a predetermined number of consecutive superframes for a NET Radio channel assignment;

(7) setting by the central controller, the priority code and including a call identifier in the GC-I channel assignment message;

(8) tuning, by the first MET, to the NET Radio channel assignment and proceeding with the voice communication.

28. In a mobile satellite system including a satellite communication switching office having a satellite antenna for receiving/transmitting a satellite message via a satellite from/to a vehicle using a mobile communication system, a central controller receiving/transmitting the satellite message from/to the satellite communication switching office issued from the vehicle via the satellite, a system for providing satellite communication between multiple users in a closed user group arrangement, comprising:

first and second mobile earth terminals (METs) responsively connected to and registering with the mobile satellite system, the first MET selecting a closed user group network identifier (NET ID) representing a NET group including the first and second METs to establish voice communication therewith and transmitting the NET ID; and

a central controller responsively connected to the first and second METs, the central controller receiving the NET ID from the first MET, validating the first MET for communication, validating the NET ID, allocating a frequency for the NET group, and broadcasting the message to the NET group including the second MET informing the NET group of the allocated frequency and the voice communication associated therewith, the second MET tuning to the frequency in response to the message broadcast by the central controller, and the central controller assigning the first MET as current speaker for the NET group,

wherein the second MET generating a scrambling vector for access to the voice communication, the scrambling vector being generated in accordance with the following operations;

(1) generating a second security key having first and second components using a first process having first and second input signals, the first input signal comprising the first security key and the second input signal comprising at least one of a transmit frequency and a receive frequency;

(2) generating the scrambling vector responsive to the second security key, and

wherein the second MET tunes to the allocated frequency for the NET group using the scrambling vector to gain access thereto.

29. In a mobile satellite system including a satellite communication switching office having a satellite antenna for receiving/transmitting a satellite message via a satellite from/to a vehicle using a mobile communication system, a central controller receiving/transmitting the satellite message from/to the satellite communication switching office issued from the vehicle via the satellite, a system for providing satellite communication between multiple users in a closed user group arrangement, comprising:

first and second mobile earth terminals (METs) responsively connected to and registering with the mobile satellite system, the first MET selecting a closed user group network identifier (NET ID) representing a NET group including the first and second METs to establish voice communication therewith and transmitting the NET ID; and

a central controller responsively connected to the first and second METs, the central controller receiving the NET ID from the first MET, validating the first MET for communication, validating the NET ID, allocating a frequency for the NET group, and broadcasting the message to the NET group including the second MET informing the NET group of the allocated frequency and the voice communication associated therewith, the second MET tuning to the frequency in response to the message broadcast by the central controller, and the central controller assigning the first MET as current speaker for the NET group,

wherein the system further providing dual standby operation permitting voice communication alternately between a closed user group arrangement (NET radio) and a mobile telephone service (MTS), and at least one of said first and second METs implementing the function of responding, by the at least one of the first and second METs, either to a MTS page request indicating the mobile telephone service is being requested or to a NET radio channel assignment request as transmitted on a GC-S channel, wherein while the at least one of the first and second METs is responding to a service request of one of the closed user group arrangement and a mobile telephone service, the at least one of the first and second METs is not required to monitor the GC-S channel for service requests of another of the closed user group arrangement and the mobile telephone service.