Patent ID: 7212551
Filing Date: 2007-05-01
Classification: H04J,H04Q

Abstract:
1. A method of time-locking a first node to a second node, the first node having a first controller that includes a first time counter and the second node having a slave controller and a master controller that includes a master time counter, the method including steps of: said first node controller sending an upstream control burst to said second node during a designated time interval, said upstream control burst including a time measurement; said slave controller directing said upstream control burst to said master controller; and said master controller comparing said time measurement with a reading of said master time counter to ascertain time alignment; wherein if said comparing indicates absence of time alignment the method implements the further steps of: said master controller sending a downstream control burst to said first controller, said downstream control burst indicating absence of time alignment; said first node sending a succession of upstream control bursts each including a measurement of said first time counter; said slave controller directing a sample of said upstream control bursts to said master controller during a designated time interval; said master controller acquiring an upstream control burst from said sample and determining a corresponding reading of said master time counter, said reading being coincident with said one of said succession of upstream control bursts; said master controller sending said corresponding reading to said first controller; and said first controller resetting said first time counter according to said corresponding reading.