US 10,958,995 B2 · Determination of the latency of an optical transmission link

Abstract

Disclosed is a method for determining the link latency of an optical transmission link which includes an end node at each end and one or more pass-through nodes. Each pair of neighboring nodes is connected, at a connection port of each node, by an optical connecting path. Each pass-through node includes an optical pass-through path between its connection ports. The optical connecting paths and optical pass-through paths form an optical link path. A delimiter device includes a delimiter element provided at each connection port of each node. The delimiter element forms a demarcation within the optical link path. According to the method the following steps are carried out: measuring, for each pair of neighboring nodes, a section latency by transmitting a section probe signal from a first one of the pair of nodes to the second one of the pair of nodes; measuring, at the first node, a first time delay of a first reflection signal, which is created by the delimiter element of the delimiter device of the first node by reflecting a power portion of the section probe signal, and a second time delay of a second reflection signal, which is created by the delimiter element of the delimiter device of the second node by reflecting a power portion of the section probe signal received from the first node; and calculating the section latency as half the difference between the second time delay and the first time delay; determining, for each pass-through node either theoretically or by measurement, a pass-through latency of an internal optical pass-through path between the delimiter elements of the delimiter devices of the respective pass-through node; and adding all section latencies and pass-through latencies in order to obtain the link latency of the optical link path.

Claims15

Dependent claims

A method for determining the link latency of an optical transmission link,

(a) wherein the optical transmission link comprises an end node at each end thereof and one or more pass-through nodes, wherein each pair of neighboring nodes is connected, at a connection port of each node, by an optical connecting path, and wherein each pass-through node comprises an optical pass-through path between its connection ports, the optical connecting paths and optical pass-through paths forming an optical link path, and
(b) wherein a delimiter device comprising a delimiter element is provided at each connection port of each node, and wherein the delimiter element forms a demarcation within the optical link path,
the method comprising the steps of:
(c) measuring, for each pair of neighboring nodes, a section latency by
(i) transmitting a section probe signal from a first one of the pair of nodes to the second one of the pair of nodes,
(ii) measuring, at the first node, a first time delay of a first reflection signal, which is created by the delimiter element of the delimiter device of the first node by reflecting a power portion of the section probe signal, and a second time delay of a second reflection signal, which is created by the delimiter element of the delimiter device of the second node by reflecting a power portion of the section probe signal received from the first node, and
(iii) calculating the section latency as half the difference between the second time delay and the first time delay,
(d) determining, for each pass-through node either theoretically or by measurement, a pass-through latency of an internal optical pass-through path between the delimiter elements of the delimiter devices of the respective pass-through node, and
(e) adding all section latencies and pass-through latencies in order to obtain the link latency of the optical link path.

6 more elements

An optical transmission link comprising

(a) an end node at each end thereof and one or more pass-through nodes and a central control device, which is connected to selected ones of the end nodes and pass-through nodes, wherein a first node of each pair of neighboring nodes comprises a first connection port and a second node of the respective pair of neighboring nodes comprises a second connection port, the first and second connection ports being connected by an optical connecting path, and wherein each pass-through node comprises an optical pass-through path which optically connects its connection ports, the optical connecting paths and optical pass-through paths forming an optical link path,
(b) wherein a first node of each pair of neighboring nodes comprises
(i) an optical probe signal transceiver configured to create and output, at an optical transceiver port, optical probe signals and to receive, at the optical transceiver port, reflected or transmitted probe signal portions and to output, at an electrical output port, an electrical receive signal that is created by opto-electrically converting the reflected or transmitted probe signal portions received,
(ii) a first delimiter device comprising a first port, which is connected to or defines the first connection port and which has a probe signal port that is connected to the optical transceiver port via an optical probe signal path,
(iii) wherein the first delimiter device is configured to create, by means of a delimiter element provided within the optical pass-through path, a first reflection signal by reflecting a power portion of a probe signal received at the probe signal port, the first reflection signal being output at the probe signal port, and to transmit a power portion of the probe signal to the first connection port,
(iv) a time delay measurement device to which the electrical receive signal is fed by the optical probe signal transceiver, the time delay measurement device being configured to measure one or more time delays between at least a first and a second signal from the group of a transmitted probe signal, a reflected probe signal portion and a transmitted probe signal portion, and
(v) a control device which is configured to control the optical probe signal transceiver and the time delay measurement device,
(c) wherein the second node of each pair of neighboring nodes comprises a second delimiter device having a first port, which is connected to or defines the second connection port, the second delimiter device being configured to reflect, by means of a delimiter element provided within the optical pass-through path, a power portion of a probe signal received at the second connection port, the reflected power portion of the probe signal being output at the first port, and
(d) wherein each control device of each first node is configured to control the optical probe signal transceiver and the time delay measurement device in such a way
(i) that the optical probe signal transceiver creates a section probe signal at a start time, wherein a first reflection signal created by the first delimiter device of the first node and a second reflection signal created by the second delimiter device of the second node are received and opto-electrically converted by the optical probe signal transceiver, and
(ii) that the time delay measurement device measures, relative to the start time or another reference time, a first time delay of a first reflection signal created by the first delimiter device by reflecting a power portion of the section probe signal, and a second time delay of a second reflection signal created by the second delimiter device by reflecting a power portion of the section probe signal received from the first node,
(iii) wherein each control device of each first node is configured to calculate a section latency of the optical path between the delimiter element of the delimiter device of the first node and the delimiter element of the delimiter device of the second node of the respective pair of nodes as half the difference between the second time delay and the first time delay, and
(e) wherein the central control device is configured to receive all section latencies from each first node of each pair of neighboring nodes and to determine a link latency of the optical link path using the sum of all section latencies and a sum of all pass-through latencies.

10 more elements

Dependencies are inferred from the claim text.

Determination of the latency of an optical transmission link

Life of this patent

Determination of the latency of an optical transmission link

Life of this patent

Abstract

Claims15