Distributed voting system and method for land mobile radio system

• US 7,830,832 B2
• Filed: 04/20/2004
• Issued: 11/09/2010
• Est. Priority Date: 04/20/2004
• Status: Active Grant

• Current Assignee: Eagle Technology, LLC (L3Harris Technologies, Inc.)
• Original Assignee: Pine Valley Investments, Inc. (L3Harris Technologies, Inc.)
• Inventors: Young, Stewart
• Primary Examiner(s): Shah; Chirag G
• Assistant Examiner(s): Reddivalam; Srinivasa R
• Application Number:
  US10/828,019
• Publication Number:
  US 20050232295A1
• Time in Patent Office: 2,394 Days
• Field of Search: 370/329, 370/341, 370/431, 370/437, 370/331, 370/332, 370/333
• US Class Current: 370/329
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/082 selecting best antenna path

Abstract

A distributed Internet Protocol (IP) voting system and method for use in Land Mobile Radio (LMR) Systems having a central send-and-receive site and one or more receive-only sites. In the distributed voting system, receive-only sites are directly linked to the control point using a network and associated packet transmission protocol. This may be a high-speed asynchronous data link such as a standard IP network link. Each remote site receiving digital data, calculates a bit error for that data. This error calculation is incorporated into the data header information. The data header information and data are placed in an IP packet and transmitted as a User Data Protocol (UDP) message to the control point. The control point selects the lowest bit rate data message, or the first control message, and retransmits it using a standard radio air interface protocol, such as the APCO Project 25 air interface protocol.

Claims

1. A distributed voter system for selecting at least one of several signals for transmission, comprising:

a plurality of remote receive-only site systems each remote receive-only site system comprising;

a first receiver configured for receiving a signal transmitted from a communication device,

a first processor configured for determining a quality measure of said received signal, and for producing a transfer signal comprising said received signal and said quality measure;

a plurality of network connections connecting each of said plurality of remote receive-only site systems to a common communications network;

a receive-and-transmit site system communicatively coupled to said plurality of remote receive-only site systems via said plurality of network connections established absent of intermediary voting equipment, said receive-and-transmit site system comprising

a second receiver configured for asynchronously receiving said transfer signals from said plurality of remote receive-only site systems,

a second processor configured for

storing a first transfer signal having a first quality measure as a selected transfer signal in a storage device, and,

if a subsequently-received transfer signal has a quality measure better than said first quality measure, then replacing said first transfer signal with said subsequently-received transfer signal as said selected transfer signal and

at least one transmitter configured for transmitting a broadcast signal comprising substantially said received signal of said selected transfer signal.

2. The system of claim 1, wherein said transfer signal is comprised of at least one digital packet.

3. The system of claim 2, wherein said digital packet conforms to a User Datagram Protocol (UDP) format.

4. The system of claim 1, wherein

said quality measure comprises an estimate of a bit rate error of said received signal, and

said second processor is further configured for selecting said transfer signal having a smallest of a plurality of estimates of bit rate error.

5. The system of claim 4, wherein said estimate of a bit rate error is obtained using data unit synchronization bits.

6. The system of claim 1, wherein said common communications network is a Local Area Network.

7. The system of claim 6, wherein said local area network is a high speed, asynchronous network.

8. The system of claim 1, wherein said second processor selects said selected transfer signal within a predetermined time window.

9. A distributed voter method for selecting at least one of several signals for transmission, comprising the steps of:

a) receiving an input signal at a plurality of remote receive-only site systems;

b) evaluating, at each of said plurality of remote receive-only site systems, a quality measure of said input signal;

c) generating a transfer signal, at each of said plurality of remote receive-only site systems, by packaging said input signal and said quality measure as at least one data packet;

d) transmitting, from each of said plurality of remote receive-only site systems, said transfer signal to a transmit-and-receive site system using a plurality of network connections of a common communications network that are absent of intermediary voting equipment;

e) receiving asynchronously a first transfer signal and at least one subsequent transfer signal at said transmit-and-receive site system;

f) recording said first transfer signal having a first quality measure as a selected transfer signal, and, if said subsequent transfer signal has a quality measure better than said first quality measure, then replacing said first transfer signal with said subsequent transfer signal as said selected transfer signal; and

,

g) transmitting a broadcast signal from said transmit-and-receive site system, said broadcast signal comprising substantially said input signal of said selected transfer signal.

10. The method of claim 9, wherein said data packet is a digital packet.

11. The method of claim 10, wherein said generating step c) further includes the step of conforming said digital packet to a User Datagram Protocol (UDP) format.

12. The method of claim 9, wherein

said evaluating step b) further includes calculating an estimate of a bit rate error of said input signal, and

said transmit-and-receive site system is further configured for selecting said transfer signal having a smallest of a plurality of estimates of bit rate error.

13. The method of claim 12, wherein said estimate of said bit rate error is calculated using a data unit'"'"'s synchronization bits.

14. The method of claim 9, wherein said common communications network includes a Local Area Network.

15. The method of claim 14, wherein said Local Area Network includes a high speed, asynchronous network.

16. The method of claim 9, wherein said recording step f) is performed until expiration of a predetermined time window.

17. A distributed voter system for selecting at least one of several signals for transmission, comprising:

a plurality of remote receive-only site systems, each remote receive-only site system is configured for receiving an input signal, evaluating a quality measure of said received input signal, and producing a transfer signal comprising said input signal and said quality measure;

a network for asynchronously transferring said transfer signals from said plurality of remote receive-only site systems to a transmit-and-receive site system using a plurality of network connections absent of intermediary voting equipment; and

,

said transmit-and-receive site system configured for asynchronously receiving said transfer signals, and

selecting one of said transfer signals received by said transmit-and-receive site system based on said quality measure, by recording a first transfer signal having a first quality measure and, if a subsequently-received transfer signal has a quality measure better than said first quality measure, replacing said first transfer signal with said subsequently-received transfer signal as said selected transfer signal, and

transmitting a broadcast signal comprising substantially said input signal of said selected transfer signal.

18. The system of claim 17, wherein said transfer signal further comprises a digital packet.

19. The system of claim 17, wherein said digital packet conforms to a User Datagram Protocol (UDP) format.

20. The system of claim 17, wherein

said quality measure comprises an estimate of a bit rate error of said input signal, and

said transmit-and-receive site system is further configured for selecting said transfer signal having a smallest of a plurality of estimates of bit rate error.