Systems and methods for supporting phase adjustments over docsis

Abstract

A method for adjusting a phase error includes a first device detecting a phase error at a timing interface of the first device. The first device modifying a DOCSIS timing protocol parameter based upon the detected phase error. The first device causing a modification of a second device's timestamp output in a manner based upon the detected phase error by the modification of the DOCSIS timing protocol parameter.

We claim: 
     
         1 . A method for adjusting a phase error comprising:
 (a) a first device detecting a phase error at a timing interface of the first device;   (b) the first device modifying a DOCSIS timing protocol parameter based upon the detected phase error;   (c) the first device causing a modification of a second device's timestamp output in a manner based upon the detected phase error by the modification of the DOCSIS timing protocol parameter.   
     
     
         2 . The method of  claim 1  wherein the first device is a CMTS. 
     
     
         3 . The method of  claim 1  wherein the second device is a cable modem. 
     
     
         4 . The method of  claim 1  wherein the first device includes one or more devices in an R-PHY architecture. 
     
     
         5 . The method of  claim 1  wherein the DOCSIS timing protocol parameter is decreased over time after the modification. 
     
     
         6 . The method of  claim 5  wherein a DOCSIS timestamp is modified over time as the DOCSIS timing protocol parameter is modified in an opposing direction. 
     
     
         7 . The method of  claim 1  wherein the phase error is detected at an ingress precision time protocol interface of the first device. 
     
     
         8 . The method of  claim 6  wherein the DOCSIS timestamp is modified at a rate within a range specified by a corresponding DOCSIS protocol. 
     
     
         9 . The method of  claim 1  wherein said timing interface is a precision timing protocol interface. 
     
     
         10 . The method of  claim 1  wherein the DOCSIS timing protocol parameter is t-cm-adj. 
     
     
         11 . The method of  claim 1  wherein the second device's timestamp output is a precision time protocol clock timestamp output. 
     
     
         12 . The method of  claim 1  wherein the first device includes a R-MACPHY device. 
     
     
         13 . The method of  claim 1  wherein the first device includes a RPD device. 
     
     
         14 . A method for adjusting a phase error comprising:
 (a) a first device detecting a phase error at a first interface of the first device;   (b) the first device modifying a DOCSIS timing protocol parameter based upon the detected phase error;   (c) modifying of a second device's timestamp output based upon the modification of the DOCSIS timing protocol parameter.