Distributed timing control for a distributed digital communication system

The method of controlling the timing of each node in a multinode system whose nodes are interconnected by links and wherein a clock source in one of said nodes provides a reference clock signal source for all other nodes in said system, said method comprising the steps of:

• (1) operating one of said nodes as a master node to control the timing of all nodes of said system,
• (2) including a timing priority number (TPN) in a clock signal transmitted from said master node over a direct link to at least another one of said nodes,
• (3) operating each node, other than master node, so that it alters a TPN it receives over a directly connected link in a prescribed manner to form a new TPN,
• (4) further operating each node, other than said master node, so that each said node sends a clock signal together with its altered TPN to all nodes to which it is directly connected by a link,
• (5) operating each node, other than said master node to identify one of the TPNs received as a preferred TPN based upon a prescribed relationship of said received TPNs, and
• (6) controlling the timing of said nodes, other than said master node, by the clock signal received over the link over which said preferred TPN is received by said node.

A method of controlling the timing of a clock signal receiving node in a multinode system whose nodes are interconnected by links and wherein a clock source in a master one of said nodes provides a reference clock signal source for controlling the timing of all other nodes in said system, said method comprising the steps of:

• (1) receiving timing priority number (TPN) information together with a clock signal on each different link connected to said clock signal receiving node with said information representing the number of intermediate nodes each received clock signal has encountered in traveling from said master node to said clock signal receiving node,
• (2) operating said clock signal receiving node to analyze the TPN information it receives on all links to which it is connected to identify as a preferred clock signal the clock signal that has encountered the least number of intermediate nodes in traveling from said master node to reach said node,
• (3) modifying the TPN from the link from which said preferred clock signal was selected,
• (4) transmitting the modified TPN on all links to which said clock signal receiving node is connected, and
• (5) operating said signal receiving node to select said preferred clock signal as a reference timing source for said signal receiving node.

A method of controlling the timing of each node in a multinode system wherein said nodes are connected by links and wherein a clock source in a master one of said nodes provides a reference clock signal for all other nodes in said system, said method comprising the steps of:

• (1) interconnecting each of said nodes to one or more other ones of said nodes via said links,
• (2) transmitting a clock signal between each of said nodes directly interconnected by any one of said links,
• (3) activating one of said nodes to operate as a master node by providing a reference clock signal for controlling the timing of said system,
• (4) including a timing priority number (TPN) of n in the clock signal sent from said master node to all of said nodes directly connected to said master node by any one said links,
• (5) operating each node directly connected by a link to said master node and receiving said TPN of n to alter n by m to form a TPN of n+m characterizing each said directly connected receiving node,
• (6) further operating each node having a TPN of n+m to include said TPN of n+m in the clock signal transmitted to each one of said nodes to which said node having a TPN of n+m is directly connected by any one of said links,
• (7) operating all others of said nodes, other than said master node, that receives a TPN of n+m so that each of said other nodes alters a TPN it receives by m and transmits its altered TPN with a clock signal to each node to which it is directly connected by any one of said links,
• (8) operating each node that receives more than a single TPN, other than said master node, to select one of said received TPNs as a preferred received TPN, and
• (9) controlling the timing of each node, other than said master node, from clock signals transmitted over the link that applies the preferred TPN to said controlled node.

Facilities for controlling the timing of each node in a multinode system whose nodes are interconnected by links and wherein a clock source in one of said nodes provides a reference clock signal source for controlling the timing of all other nodes in said system, said facilities comprising:

• means for operating one of said nodes as a master node to control the timing of all nodes of said system,
• means for transmitting a clock signal between each pair of said nodes directly interconnected by any one of said links,
• means for including timing priority number (TPN) information in the clock signal transmitted between each pair of directly connected nodes with said information representing the priority of said clock signal,
• means for operating each clock signal receiving node, other than said master node, to analyze the TPN information it receives on all links to which it is connected to identify a preferred clock signal,
• means for modifying the TPN from the directly connected node which transmitted said preferred clock signal,
• means for transporting the modified TPN to all nodes directly connected to said clock signal receiving node, and
• means for operating each clock signal receiving node to select said preferred clock signal as a reference timing source for said receiving node.

Facilities for controlling the timing of each node in a multinode system whose nodes are interconnected by links and wherein a clock source in one of said nodes provides a reference clock signal source for all other nodes in said system, said facilities comprising:

• means for operating one of said nodes as a master node to control the timing of all nodes of said system,
• means for including a timing priority number (TPN) in the clock signal transmitted from said master node over a direct link to at least another one of said nodes,
• means for operating each node, other than master node, so that it alters a TPN it receives over a directly connected link in a prescribed manner to form a new TPN,
• means for further operating each node, other than said master node, so that each said node sends a clock signal together with its altered TPN to all nodes to which it is directly connected by a link,
• means for operating each node, other than said master node, to identify one of the TPNs received as a preferred TPN based upon a prescribed relationship of said received TPNs, and
• means for controlling the timing of each said node, other than said master node, by the clock signal received over he link over which said preferred TPN is received by said node.

Facilities for controlling the timing of each node in a multinode system wherein said nodes are connected by links and wherein a clock source in a master one of said nodes provides a reference clock signal for all other nodes in said system, said facilities comprising:

• links for directly interconnecting each of said nodes to one or more other of said nodes,
• means for transmitting a clock signal between each of said nodes directly interconnected by any one of said links,
• means for activating one of said nodes to operate as a master node by providing a reference clock signal for controlling the timing of said system,
• means for including a timing priority number (TPN) of n in the clock signal sent from said master node to all of said nodes directly connected to said master node by any one of said links,
• means for operating each node directly connected by a link to said master node and receiving said TPN of n to alter n by m to form a TPN of n+m characterizing each said directly connected receiving node,
• means for further operating each node having a TPN of n+m to include said TPN of n+m in the clock signal transmitted to each one of said nodes to which said node having a TPN of n+m is directly connected by any one of said links,
• means for operating all others of said nodes, other than said master node, that receives a TPN of n+m so that each of sad other node alters a TPN it receives by m and transmits its altered TPN with a clock signal to each node to which it is directly interconnected by any one of said links,
• means for operating each node that receives more than a single TPN, other than said master node, to select one of said received TPNs as a preferred received TPN, and
• means for controlling the timing of each node, other than said master node, from clock signals transmitted over the link that applies the preferred TPN to said controlled node.

Facilities for controlling the timing of a clock signal receiving node in a multinode system whose nodes are interconnected by links and wherein a clock source in a master one of said nodes provides a reference clock signal source for controlling the timing of all other nodes in said system, said facilities comprising:

• means for receiving timing priority number (TPN) information together with a clock signal on each different link connected to said signal receiving node with said TPN information representing the number of intermediate nodes each received clock signal has encountered in traveling from said master node to said signal receiving node,
• means for operating said signal receiving node to analyze the TPN information it receives on all links to which it is connected to identify as a preferred clock signal the clock signal that has encountered the least number of intermediate nodes in traveling from said master node to reach said signal receiving node,
• means for selecting said preferred clock signal as a reference timing source of said signal receiving node,
• means for modifying the TPN received from the link from which said preferred clock signal was received, and
• means for transmitting the modified TPN on all links to which said signal receiving node is connected.

Facilities for controlling the timing of a clock signal receiving node in a multinode system whose nodes are interconnected by links said facilities comprising:

• means for receiving timing priority number (TPN) information together with a clock signal on each different link connected to said signal receiving node with said TPN information representing the relative priority of each received clock signal,
• means for operating said signal receiving node to analyze the TPN information it receives on all links to which it is connected to identify a preferred clock signal having a preferred priority,
• means for selecting said preferred clock signal as a reference timing source for said signal receiving node,
• means for modifying the TPN received from the link from which said preferred clock signal was received, and
• means for transmitting the modified TPN on all links to which said signal receiving node is connected.

A method of controlling the timing of each nodes in a multinode system whose nodes are interconnected by links and wherein a clock source in one of said nodes provides a reference clock signal source for controlling the timing of all other nodes in said system, said method comprising the steps of:

• (1) operating one of said nodes as a master node to control the timing of all nodes of said system,
• (2) transmitting a clock signal between each pair of said nodes directly interconnected by any one of said links,
• (3) including timing priority number (TPN) information in the clock signal transmitted between each pair of directly connected nodes with said information representing the relative priority of the clock signal used by each transmitting node,
• (4) operating each signal receiving node, other than said master node, to analyze the TPN information it receives on all links to which it is connected to identify a preferred clock signal having a preferred priority, and
• (5) operating each clock signal receiving node, other than said master node, to select said preferred clock signal as a reference timing source for said receiving node,
• (6) modifying the TPN received from the link from which said preferred clock signal was received, and
• (7) transmitting the modified TPN on all links to which said receiving node is connected.