AUTOMATIC REPEAT REQUEST (ARQ) COMMUNICATION SYSTEM USING PHYSICAL LAYER MONITORING

• US 20080198786A1
• Filed: 02/20/2007
• Published: 08/21/2008
• Est. Priority Date: 02/20/2007
• Status: Active Grant

• Current Assignee: Harris Global Communications, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: NIETO, John W., Wadsworth, Michael A, Furman, William N
• Granted Patent: US 8,213,402 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end

Abstract

A communication system includes a plurality of nodes forming a wireless mesh network. A plurality of wireless communication links connect the nodes together. Each node is formed as a communications device having a physical layer and a media access control (MAC) layer in accordance with the Open System Interconnect (OSI) model and operative for transmitting and receiving communications packets to and from other nodes via the wireless communication links in an Automatic Repeat Request (ARQ) mode. The physical layer monitors channel parameters of the wireless communications link when in an ARQ mode and, based on the channel parameters, communicates to the MAC layer over-the-air (OTA) parameters used for transmitting packets.

Claims

1. A communications system, comprising:

a plurality of nodes forming a wireless mesh network;

a plurality of wireless communication links connecting the nodes together;

each node comprising a communications device having a physical layer (PHY) and a media access control (MAC) layer in accordance with the Open System Interconnect (OSI) model and operative for transmitting and receiving communications packets wirelessly to and from other nodes via the wireless communications links in an automatic repeat request (ARQ) mode, wherein said physical layer monitors channel parameters of the wireless communications link when in an ARQ mode and based on the channel parameters, communicates to the MAC layer over-the-air (OTA) parameters used for transmitting packets.

2. The communications system according to claim 1, wherein said OTA parameters comprise one of at least the bandwidth, data rate, transmit power, block size, burst length and waveform, comprising the attributes of the PHY layer including modulation type (PSQ, M_PSK, FSK, OFDM QAM, frequency hopping, spread spectrum), the symbol rate, bandwidth, error correction code scheme and rate.

3. The communications system according to claim 1, wherein said channel parameters comprise one of at least multipath, fading, signal-to-noise ratio, received signal strength (RSS), bit error rate, packet error rate and interference level.

4. The communications system according to claim 1, wherein said MAC layer includes an ARQ circuit that adds ARQ headers to communications packets at the communications device.

5. The communications system according to claim 1, wherein said MAC layer includes an ARQ circuit that provides a positive and/or negative acknowledgment based on received communications packets.

6. The communications system according to claim 1, wherein said MAC or PHY layer includes a forward error correction (FEC) encoder that encodes communications packets generated at the communications device with a forward error correction code.

7. The communications system according to claim 1, wherein said MAC or PHY layer includes a FEC decoder that decodes received packets.

8. The communications system according to Claim 1, wherein said physical layer includes a channel monitoring circuit the monitors the channel parameters and a processor that determines what OTA parameters should be changed.

9. The communications system according to claim 1, wherein said channel monitoring circuit and processor implements an interface to the MAC layer for communicating to the MAC the OTA parameters.

10. An apparatus comprising:

a wireless transceiver comprising a physical layer (PRY) and a media access control (MAC) layer in accordance with the Open System Interconnect (OSI) model and operative for transmitting and receiving communications packets wirelessly to and from other transceivers over a wireless communications link in an automatic repeat request (ARQ) mode;

a channel monitoring circuit at the physical layer that monitors channel parameters of a wireless communications link over which the wireless transceiver communicates packets when in an ARQ mode; and

a processor at the physical layer that receives and processes the monitored channel parameters from the monitoring circuit and communicates to the MAC layer over-the-air (OTA) parameters used for transmitting communications packets.

11. The apparatus according to claim 10, wherein said OTA parameters comprise one of at least the bandwidth, data rate, transmit power, block size, burst length and waveform, comprising the attributes of the PHY layer including modulation type (PSQ, M_PSK, FSK, OFDM QAM, frequency hopping, spread spectrum), the symbol rate, bandwidth, error correction code scheme and rate.

12. The apparatus according to claim 10, wherein said channel parameters comprise one of at least multipath, fading, signal-to-noise ratio, received signal strength (RSS), bit error rate, packet error rate, and interference level.

13. The apparatus according to claim 10, wherein said MAC layer includes an ARQ circuit that adds ARQ headers to communication packets at the communications device.

14. The apparatus according to claim 10, wherein said MAC layer includes an ARQ circuit that provides a positive and/or negative acknowledgment based on received communications packets.

15. The apparatus according to claim 10, wherein said MAC or PHY layer includes a forward error correction (FEC) encoder that adds a FEC code to data packets generated at the communications device.

16. The apparatus according to claim 10, wherein said MAC or PHY layer includes a FEC decoder that decodes received packets.

17. A method for communicating, comprising:

transmitting a communications packet wirelessly from a transceiver to a destination node using an automatic repeat request (ARQ) protocol, wherein the transceiver includes a physical layer and a media access control (MAC) layer;

monitoring from the physical layer at the communications channel that exists between the transceiver and destination node when the transceiver is in an ARQ mode;

communicating, over-the-air-(OTA)-parameters, from the physical layer to MAC layer based on monitored channel parameters; and

adapting the OTA parameters based on the monitored channel parameters.

18. A method according to claim 17, which further comprises monitoring channel parameters that comprise one of at least multipath, fading, signal-to-noise ratio, received signal strength (RSS), bit error rate, packet error rate and interference level.

19. A method according to claim 17, which further comprises transmitting OTA parameters that comprise one of at least the bandwidth, data rate, transmit power, block size, burst length and waveform, comprising the attributes of the PHY layer including modulation type (PSQ, M_PSK, FSK, OFDM QAM, frequency hopping, spread spectrum), the symbol rate, bandwidth, error correction code scheme and rate.

20. A method according to claim 17, which further comprises adding ARQ headers to communications packets that are transmitted from the transceiver.

21. A method according to claim 17, which further comprises encoding communications packets with a forward error correction (FEC) code.