Distributed voting system and method for land mobile radio system

• US 20050232295A1
• Filed: 04/20/2004
• Published: 10/20/2005
• Est. Priority Date: 04/20/2004
• Status: Active Grant

• Current Assignee: Eagle Technology, LLC (L3Harris Technologies, Inc.)
• Original Assignee: M/A Com, Inc. (MACOM Technology Solutions Holdings, Inc.)
• Inventors: Young, Stewart
• Granted Patent: US 7,830,832 B2
• Time in Patent Office: Days
• US Class Current: 370/437
• 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 receivers, each receiver comprising at least one receiving channel capable of acquiring a received signal;

a receiver processor capable of evaluating a quality measure of said received signal and signal transmitting circuitry for producing a transfer signal, said transfer signal comprising said received signal and said quality measure;

a plurality of network connections whereby each of said plurality of receivers is connected to a common communications network;

a transmitter connected to said common communications network, said transmitter comprising signal receiving circuitry for receiving said transfer signals from said plurality of receivers;

a transmitter processor capable of selecting one of said transfer signals based on said quality measure; and

at least one transmission channel capable of transmitting a broadcast signal comprising substantially said received signal portion of said selected transfer signal.

2. The system of claim 1 in which said transfer signal is a digital packet.

3. The system of claim 2 in which said digital packet conforms to 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 input signal, and wherein said means for selecting selects said transfer signal having a smallest of said estimates of bit rate error.

5. The system of claim 4 in which said estimate of a bit rate error is performed using a data unit synchronization bits

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

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

8. The system of claim 1 in which said selection occurs 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) remotely receiving an input signal at a plurality of receiving sites;

b) evaluating, at each of said plurality of receiving sites, a quality measure of said input signal;

c) packaging, at each of said plurality of receiving sites, said input signal and said quality measure as a data packet;

d) transmitting, from each of said plurality of receiving sites, said data packet to a central controller as a transfer signal using a common communications network;

e) centrally receiving a plurality of transfer signals at said central controller;

f) selecting one of said transfer signals based on said quality measure; and

,

g) transmitting a broadcast signal, said broadcast signal comprising substantially said input signal portion of said of said selected transfer signal.

10. The system of claim 9 in which said step c) of packaging further includes the step of converting said data packet to a digital packet.

11. The system of claim 10 in which said step c) of packaging further includes the step of conforming said digital packet conforms to User Datagram Protocol (UDP) format.

12. The system of claim 9 wherein said step b) of evaluating a quality measure further includes the step of calculating an estimate of a bit rate error of said input signal;

and wherein said means for selecting selects said transfer signal having a smallest of said estimates of bit rate error.

13. The system of claim 12 in which said step calculating said bit rate error further includes the step of using a data unit'"'"'s synchronization bits.

14. The system of claim 9 in which said step of using a common communications network further includes the step of using a Local Area Network.

15. The system of claim 14 in which said step of using a Local Area Network further includes the step of using s a high speed, asynchronous network.

16. The system of claim 9 in which said step f) of selecting further includes the step of of stopping selection after a predetermined time window.

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

a plurality of receivers, each receiver including means for receiving input signals, means for evaluating a quality measure of said received signal and means for producing a transfer signal, said transfer signal comprising said input signal and said quality measure;

a network means for transferring said transfer signals; and

,

a transmitter having means for receiving said transfer signals;

means for selecting one of said transfer signals based on said quality measure and means for transmitting a broadcast signal comprising substantially said input signal portion of said of said selected transfer signal.

18. The system of claim 17 in which said transfer signal further comprises a digital packet.

19. The system of claim 17 in which said digital packet conforms to 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 wherein said means for selecting selects said transfer signal having a smallest of said estimates of bit rate error.