Mapping control protocol time onto a physical layer
First Claim
Patent Images
1. A method comprising:
- in a communication device comprising a Media Access Control (MAC) layer and a Physical (PHY) layer;
determining a MAC layer data rate of the MAC layer;
determining a PHY layer data rate at which communication will occur over a physical communication medium; and
at the MAC layer;
determining a rate difference between the MAC layer data rate and the PHY layer data rate;
communicating a data flow from the MAC layer to the PHY layer, the data flow comprising data for communication over the physical communication medium, including inserting IDLE characters into the data flow responsive to the rate difference; and
in the PHY layer, replacing, prior to forward error correction encoding, selected IDLE characters among those inserted into the data flow at the MAC layer with data bytes of the data flow received from the MAC layer to adapt to the rate difference between the MAC layer and the PHY layer.
6 Assignments
0 Petitions
Accused Products
Abstract
An IDLE insertion technique maps MPCP time onto an EPoC PHY. The techniques address the variability of bandwidth due to bit loading over time. The techniques allow MPCP time to follow wall time at the MAC layer while tracking bytes at the PMD layer. The techniques also facilitate use of the EPON MAC with few changes in an EPoC environment. The bandwidth allocation messages may follow the same format as in EPON, and the techniques may implement IDLE insertion that accounts for EPoC PHY FEC overhead and datarate differences compared to the MAC.
26 Citations
20 Claims
-
1. A method comprising:
-
in a communication device comprising a Media Access Control (MAC) layer and a Physical (PHY) layer; determining a MAC layer data rate of the MAC layer; determining a PHY layer data rate at which communication will occur over a physical communication medium; and at the MAC layer; determining a rate difference between the MAC layer data rate and the PHY layer data rate; communicating a data flow from the MAC layer to the PHY layer, the data flow comprising data for communication over the physical communication medium, including inserting IDLE characters into the data flow responsive to the rate difference; and in the PHY layer, replacing, prior to forward error correction encoding, selected IDLE characters among those inserted into the data flow at the MAC layer with data bytes of the data flow received from the MAC layer to adapt to the rate difference between the MAC layer and the PHY layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A system comprising:
-
control circuitry characterized by a control layer data rate; and communication medium circuitry comprising; a communication interface to a communication medium;
where;the communication medium characterized by a transmit data rate at which the communication interface places data onto the communication medium;
at the control circuitry;determining a rate difference between the control layer data rate and the transmit data rate; preparing a data flow for the communication medium circuitry; and responsive to the rate difference, inserting spacing characters in the data flow to the communication medium circuitry, wherein the spacing characters are inserted into the data flow after a start of a packet and before an interpacket gap; and the communication medium circuitry configured to; replace selected spacing characters among those inserted into the data flow at the control circuitry with data bytes of the data flow received from the control circuitry to adapt to the rate difference between the control layer data rate and the transmit data rate. - View Dependent Claims (13, 14, 15, 16, 17, 18)
-
-
19. A system comprising:
-
an optical communication interface; a coaxial communication interface; control circuitry in communication with the optical communication interface and the coaxial communication interface, the control circuitry comprising; a Media Access Control (MAC) layer configured to operate at a fixed MAC layer data rate; and a Physical (PHY) layer configured to transmit data through the coaxial communication interface at a PHY layer data rate subrated with respect to the fixed MAC layer data rate;
where;the MAC layer is configured to; determine a rate difference between the fixed MAC layer data rate and the PHY layer data rate; communicate a datastream from the MAC layer to the PHY layer, the datastream comprising data bits for communication through the coaxial communication interface; and insert, into the datastream, IDLE characters for adapting the PHY layer to the rate difference; and the PHY layer is configured to; hold data from the datastream received from the MAC layer; and replace selected IDLE characters among those inserted at the MAC layer with the data from the datastream that was held in the PHY layer due to the rate difference. - View Dependent Claims (20)
-
Specification