Granted Patent B2

US 12,294,414 · App. 18/003,955 · Granted May 6, 2025

Inventors: Byungkyu Ahn (Seoul, KR); Sangrim Lee (Seoul, KR); Hojae Lee (Seoul, KR); JaYeong Kim (Seoul, KR)

Assignee: LG ELECTRONICS INC.

H04B10/70

Abstract

Claims (51)

1. A method for transmitting a first pulse train in a quantum communication system, the method performed by an apparatus and comprising:

receiving a random access (RA) preamble from another apparatus;

transmitting a random access response (RAR) to the another apparatus in response to the RA preamble;

performing a radio resource control (RRC) connection procedure with the another apparatus;

receiving data from the another apparatus; and

decoding the data based on key information,

wherein, based on that the first pulse train is generated in a laser diode of the apparatus and the first pulse train is transmitted from the apparatus to the another apparatus through a quantum channel after respectively passing through a first path and a second path, the key information is determined,

wherein the second path includes N paths,

wherein the N has a value less than or equal to K,

wherein the N and the K are natural numbers, and

wherein K is a maximum number of the second path.

2. The method of claim 1 , wherein the laser diode is an element that supports tuning of wavelength.

3. The method of claim 1 , wherein a last pulse of the first pulse train passes through the N paths during a time where the laser diode tunes wavelength.

4. The method of claim 3 , wherein a length of each of the N paths is determined based on a length of the first path, a value for what number the path is among the N paths, a time interval between pulses of the laser diode and a speed of light in fiber.

5. The method of claim 1 , wherein a value of the K is determined based on a time for tuning wavelength of the laser diode and a time interval between pulses of the laser diode.

6. The method of claim 1 , wherein the second path includes a storage line.

7. The method of claim 6 , wherein the first pulse train is branched and passes through the first path and the second path,

wherein the first pulse train passing through the second path joins in a beam splitter of the apparatus after the first pulse train passing through the first path.

8. The method of claim 1 , wherein the apparatus detects a second pulse train related to transmission of the first pulse train based on a first tunable filter and a second tunable filter;

wherein each of the first tunable filter and the second tunable filter is an element that supports variably converting wavelength passed through each of the first tunable filter and the second tunable filter.

9. The method of claim 8 , wherein the first tunable filter passes the second pulse train having first wavelength during a switching time of the second tunable filter,

wherein the first tunable filter passes the second pulse train having second wavelength after the switching time of the second tunable filter.

10. An apparatus comprising:

a transceiver;

at least one memory; and

at least one processor operably coupled with the at least one memory and the transceiver, wherein the at least one processor is configured to:

control the transceiver to receive a random access (RA) preamble from another apparatus;

control the transceiver to transmit a random access response (RAR) to the another apparatus in response to the RA preamble;

perform a radio resource control (RRC) connection procedure with the another apparatus;

control the transceiver to receive data from the another apparatus; and

decode the data based on key information,

wherein the apparatus includes a laser diode, a first path and a second path,

wherein, based on that the first pulse train is generated in a laser diode of the apparatus and the first pulse train is transmitted from the apparatus to the another apparatus through a quantum channel after respectively passing through a first path and a second path, the key information is determined,

wherein the second path includes N paths,

wherein the N has a value less than or equal to K,

wherein the N and the K are natural numbers, and

wherein K is a maximum number of the second path.

11. An apparatus comprising:

at least one memory; and

at least one processor operably coupled to the at least one memory, wherein the at least one processor is configured:

control a transceiver to receive a random access (RA) preamble from another apparatus;

control the transceiver to transmit a random access response (RAR) to the another apparatus in response to the RA preamble;

perform a radio resource control (RRC) connection procedure with the another apparatus;

control the transceiver to receive data from the another apparatus; and

decode the data based on key information,

wherein the apparatus includes a laser diode, a first path and a second path,

wherein, based on that the first pulse train is generated in a laser diode of the apparatus and the first pulse train is transmitted from the apparatus to the another apparatus through a quantum channel after respectively passing through a first path and a second path, the key information is determined,

wherein the second path includes N paths,

wherein the N has a value less than or equal to K,

wherein the N and the K are natural numbers, and

wherein K is a maximum number of the second path.

Assignments (1)

Continuity (1)

References Cited (18)