US 9,794,903 B2Granted

Synchronization of distributed nodes

AssigneeZiva Corporation

InventorsDavid Smith, Anis Husain, Jeremy Rode, Mark Hsu

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Abstract

Dynamic, untethered array nodes are frequency, phase, and time aligned/synchronized, and used to focus their transmissions of the same data coherently on a target or in the target's direction, using time reversal or directional beamforming. Information for alignment/synchronization may be sent from a master node of the array to other nodes, over non-RF links, such as optical and acoustic links. Some nodes may be connected directly to the master nodes, while other nodes may be connected to the master node through one or more transit nodes. A transit nodes may operate to (1) terminate the link when the alignment/synchronization information is intended for the node, and (2) pass through the alignment/synchronization information to another node without imposing its local clock properties on the passed through alignment/synchronization information. In this way, an end point node may be aligned/synchronized to the master node without a direct link between the two nodes.

Claims17

Dependent claims

A method of synchronizing an array of at least three ad hoc nodes, the method comprising steps of:

receiving from a master node of the array a first non-radio frequency (non-RF) signal carrying a first radio frequency (RF) signal, the step of receiving being performed at a first transit slave node of the array over a first non-RF side channel link, the first RF signal including properties of a local time reference of the master node;
passing through at least a first portion of the first non-RF signal through the first transit slave node to an end-point node without imposing clock properties of the first transit slave node on the first portion of the first non-RF signal and without converting the first portion of the first non-RF signal to an electrical signal and retransmitting the electrical signal on a new non-RF carrier, the first portion of the first non-RF signal carrying at least a first portion of the first RF-signal;
synchronizing local time reference of the end-point node to the local time reference of the master node using the properties of the local time reference of the master node included in the first portion of the first RF-signal, the step of synchronizing the local time reference of the end-point node to the local time reference of the master node comprising frequency, phase, and time alignment of the end-point node;
and
synchronizing local time reference of the first transit slave node to the local time reference of the master node using the properties of the local time reference of the master node carried by a second portion of the first RF-signal, the second portion of the first RF-signal being carried in a second portion of the first non-RF signal, the step of synchronizing the local time reference of the first transit slave node to the local time reference of the master node comprising frequency, phase, and time alignment of the first transit slave node;
wherein each node of the at least three ad hoc nodes includes a separate clock associated with said each node;
and
wherein said each node is free to move in at least one dimension in absolute terms, with respect to a target, and with respect to other nodes of the at least three ad hoc nodes.

5 more elements

An array of at least three ad hoc nodes, the array comprising:

a communication node comprising at least one communication node processor, a communication node radio frequency (RF) transceiver coupled to the at least one communication node processor, a communication node local time reference, and a communication node non-RF processing module coupled to the at least one communication node processor;
a master node comprising at least one master node processor, a master node RF transceiver coupled to the at least one master node processor, a master node local time reference, and a master node non-RF transceiver coupled to the at least one master node processor;
and
an end-point node comprising at least one end-point node processor, an end-point node RF transceiver coupled to the at least one end-point node processor, an end-point node local time reference, and an end-point node non-RF transceiver coupled to the at least one end-point node processor;
wherein:
the communication node non-RF processing module comprises a non-RF transceiver configured to receive from free-space a first non-RF signal, a non-RF splitter configured to separate the first non-RF signal into a first component terminated at the communication node and a second component passed through the communication node into free-space without properties of the communication node local time reference being imposed on the second component and without converting the second component to an electrical signal, and electronic circuitry configured to obtain from the first component data in the first non-RF signal;
the master node is configured by the at least one master node processor to emit the first non-RF signal over a first non-RF side channel link, the first non-RF signal carrying an RF signal including properties of the master node local time reference;
the communication node is configured by the at least one communication node processor to synchronize the communication node local time reference to the master node local time reference using the properties of the master node local time reference included in the first non-RF signal received by the communication node;
the end-point node is configured by the at least one end-point node processor to receive the second component passed through the communication module using the end-point node non-RF transceiver and synchronize the end-point node local time reference to the master node local time reference using the properties of the master node local time reference in the second component of the first non-RF signal passed through the communication node;
each node of the array is free to move in three dimensions in absolute terms, with respect to a target, and with respect to other nodes of the array;
and
said each node of the array is free to rotate around a plurality of axes.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/476,738Filed 4 Sep 2014 · us provisional application
Priority: 23 Sep 2013
Published: US 2015/0085853 A126 Mar 2015
Granted: 17 Oct 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H04W 56/0025
Synchronization between nodes: synchronizing potentially movable access points
H04B 7/024
Site diversity; Macro-diversity: co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input…
H04W 56/0015
Synchronization between nodes: one node acting as a reference for the others
H04W 84/18
Network topologies: self-organising networks, e.g. ad-hoc networks or sensor networks