×

Distributed timing recovery for a distributed communication system

  • US 4,939,752 A
  • Filed: 05/31/1989
  • Issued: 07/03/1990
  • Est. Priority Date: 05/31/1989
  • Status: Expired due to Term
First Claim
Patent Images

1. Apparatus for use in a multinode system of the type in which each node receives, from each other node to which each is directly connected, (a) a clock signal and (b) an associated input timing priority number (TPN), and in which each node transmits, to said each other node, (a) the particular received clock signal having the lowest associated TPN and (b) an output TPN, the TPNs being such that, at any particular time, the clock signal from a particular node, a current one of a plurality of master nodes becomes distributed to each of the other nodes as a current master clock signal, each of said plurality of master nodes being prioritized in accordance with an assigned master priority number, the higher priority node having the lower master priority number with the highest priority node having the lowest master priority number, said apparatus including, at each individual one of said plurality of master nodes of the system:

  • means for operating said individual node in a master mode in which its output TPN is a predetermined number which is a function of a predetermined mastr priority number assigned to that node,means for operating said individual node in a mode other than said master mode in which its output TPN is a function of the TPN associated with said particular received clock signal,means for switching said individual node to its master mode upon the disappearance of said current master clock signal from said system, andmeans responsive to the receipt of a TPN which is smaller than said TPN predetermined number for thereafter switching said individual node back to its other than said master mode,whereby said multinode system converges to a stable state in which an operative one of said master nodes having the highest priority operates in its master mode as said current master node and each other of said master nodes operates in its other than said master mode.

View all claims
  • 9 Assignments
Timeline View
Assignment View
    ×
    ×