Physical layer device that connects to a shared media and method for operating a physical layer device that connects to a shared media

1. A physical layer (PHY) device that is compatible with the IEEE 802.3 standard and that utilizes carrier-sense multiple access with collision detection (CSMA/CD) for media access control (MAC) to a shared media, the PHY device comprising:

a physical coding sublayer transmitter (PCS-TX);

a physical medium attachment transmitter (PMA-TX);

a physical coding sublayer receiver (PCS-RX);

a physical medium attachment receiver (PMA-RX); and

a media access priority manager configured to operate above the PCS-TX and below a CSMA/CD MAC layer and to initiate transmission of an indication of a priority of a frame that is to be transmitted onto the shared media;

wherein the media access priority manager is further configured to:

receive priorities of frames to be transmitted onto the shared media from other PHY devices that are connected to the shared media, wherein the priorities are received via beacons sent from the other PHY devices; and

determine whether or not to transmit its frame onto the shared media based on an arbitration between the priority of its frame relative to the priorities of the frames to be transmitted from the other PHY devices that were received at the media access priority manager from the other PHY devices that are connected to the shared media;

wherein the media access priority manager in the PHY device is configured to indicate the priority of its frame by transmitting an indication of priority in a media access priority beacon that is generated in the PHY device.

2. The PHY device of claim 1 , wherein the PHY device is compatible with IEEE 802.3cg.

3. The PHY device of claim 1 , wherein the media access priority manager is configured to initiate transmission of its frame if the priority of its frame is higher than the priorities of all the frames to be transmitted from the other PHY devices.

4. The PHY device of claim 1 , wherein the media access priority manager is configured to initiate transmission of its frame if the priority of its frame matches a highest priority from the priorities of all the frames to be transmitted from the other PHY devices.

5. The PHY device of claim 1 , wherein the media access priority manager is configured to learn the priority of its frame through an MII interface.

6. The PHY device of claim 1 , wherein the media access priority manager is configured to learn the priority of its frame through a serial peripheral interface (SPI).

7. The PHY device of claim 1 , wherein the media access priority manager is configured to learn the priority of its frame through information in a header of the frame.

8. A method of operating a physical layer (PHY) device that is compatible the IEEE 802.3 standard and that utilizes carrier-sense multiple access with collision detection (CSMA/CD) for media access control (MAC) to a shared media, the method comprising:

identifying a priority of a frame that is to be transmitted onto the shared media from the PHY layer device; and

transmitting an indication of the priority of the frame onto the shared media from the PHY device;

wherein the PHY device is compatible with IEEE 802.3cg, and wherein the PHY device comprises:

a physical coding sublayer transmitter (PCS-TX);

a physical medium attachment transmitter (PMA-TX);

a physical coding sublayer receiver (PCS-RX);

a physical medium attachment receiver (PMA-RX); and

a media access priority manager configured to operate above the PCS-TX and below a CSMA/CD MAC layer and to initiate transmission of the indication of a priority of a frame that is to be transmitted onto the shared media;

further comprising:

receiving priorities of frames to be transmitted onto the shared media from other PHY devices that are connected to the shared media; wherein the priorities are received via beacons sent from the other PHY devices; and

determining whether or not to transmit its frame onto the shared media based on an arbitration between the priority of its frame relative to the priorities of the frames to be transmitted from the other PHY devices that were received at the media access priority manager from the other PHY devices that are connected to the shared media;

wherein the media access priority manager in the PHY device is configured to indicate the priority of its frame by transmitting an indication of priority in a media access priority beacon that is generated in the PHY device.

9. The method of claim 6 , wherein the indication of the priority of the frame is transmitted onto the shared media from the PHY device according to IEEE 802.3cg.

10. The method of claim 8 , further comprising initiating transmission of its frame if the priority of its frame is higher than the priorities of all the frames to be transmitted from the other PHY devices.

11. The method of claim 8 , further comprising learning the priority of its frame through an MII interface.

12. The method of claim 8 , further comprising learning the priority of its frame through a serial peripheral interface (SPI).

13. The method of claim 8 , further comprising learning the priority of its frame through information in a header of the frame.

14. A communications network comprising:

a shared media, wherein the shared media is a twisted-pair wire;

multiple physical layer (PHY) devices connected to the shared media and compatible with the IEEE 802.3 standard and that utilize carrier-sense multiple access with collision detection (CSMA/CD) for media access control (MAC) to the shared media, each PHY device comprising:

a physical coding sublayer transmitter (PCS-TX);

a physical medium attachment transmitter (PMA-TX);

a physical coding sublayer receiver (PCS-RX);

a physical medium attachment receiver (PMA-RX); and

a media access priority manager configured to operate above the PCS-TX and below a CSMA/CD MAC layer and to:

initiate transmission of an indication of a priority of a frame that is to be transmitted onto the shared media;

receive priorities of frames to be transmitted onto the shared media from other PHY devices that are connected to the shared media, wherein the priorities are received via beacons sent from the other PHY devices; and

determine whether or not to transmit its frame onto the shared media based on an arbitration between the priority of its frame relative to the priorities of the frames to be transmitted from the other PHY devices that were received at the media access priority manager from the other PHY devices that are connected to the shared media:

wherein the media access priority manager in the PHY device is configured to indicate the priority of its frame by transmitting an indication of priority in a media access priority beacon that is generated in the PHY device.

15. The communications network of claim 14 , wherein the media access priority manager is configured to initiate transmission of its frame if the priority of its frame is higher than the priorities of all the frames to be transmitted from the other PHY devices.