CN106982397A - Substation communication network and its time synchronized safety method based on passback detection - Google Patents
Substation communication network and its time synchronized safety method based on passback detection Download PDFInfo
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- CN106982397A CN106982397A CN201710342390.4A CN201710342390A CN106982397A CN 106982397 A CN106982397 A CN 106982397A CN 201710342390 A CN201710342390 A CN 201710342390A CN 106982397 A CN106982397 A CN 106982397A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
- H04Q11/0062—Network aspects
- H04Q11/0067—Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00019—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using optical means
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0647—Synchronisation among TDM nodes
- H04J3/065—Synchronisation among TDM nodes using timestamps
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
- H04Q11/0062—Network aspects
- H04Q2011/0079—Operation or maintenance aspects
- H04Q2011/0081—Fault tolerance; Redundancy; Recovery; Reconfigurability
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/16—Electric power substations
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Small-Scale Networks (AREA)
- Optical Communication System (AREA)
Abstract
The invention belongs to intelligent substation technical field of network security, more particularly to a kind of substation communication network and its time synchronized safety method based on passback detection, network includes：Optical network unit ONU, synchronous optical line terminal OLT and EPON protocol processors；Wherein, the interface module of each optical network unit ONU has two interfaces to have identical state forever, and substation network uses the redundant configuration mode of active and standby link.Method includes：Timestamp is passed to each optical network unit ONU by the EPON protocol processors of intelligent substation network；ONU calculates round-trip delay RTT, and sends message and the local time information that will be updated simultaneously to synchronous optical line terminal OLT from active and standby link；OLT determines whether security risk occur to terminate the time synchronized of ONU sides；Otherwise ONU tracks any timestamp all the way in active and standby link.
Description
Technical field
The invention belongs to intelligent substation technical field of network security, more particularly to a kind of transformer station based on passback detection
Communication network and its time synchronized safety method.
Background technology
In intelligent substation, communication network is connected to various intelligent electronic devices, the reliability service under unified clock.Such as
Fruit clock is under attack, and equipment sequential will be caused chaotic, and equipment malfunction is made, and is normally run to system and brings great destruction.Intelligence
One of core technology that can be in transformer station is exactly Perfect Time synchronization, pair when destruction for the running of intelligent substation strike
It is fatal, it can cause the transmission delay and confusion of data, causes the abnormal running of intelligent substation, therefore improve change
The network clocking in power station also becomes most important safely, needs to be goed deep into for New Generation of Intelligent transformer station time synchronized safety problem
Research.
Man-in-the-middle attack situation present in intelligent substation communication network time synchronization process.Man-in-the-middle attack node energy
Enough temporal information values that optical network unit ONU is sent to by changing, come it is any change send message to optical network unit ONU when
Between, and then link Round-Trip Time RTT value is manipulated, this also implies that attacker can arbitrarily manipulate optical network unit ONU section
The real-time clock of point, can make the reality of the optical network unit ONU clock node equipment progressively stray light road terminal OLT node devices
Shi Shizhong can not be found also be switched standby clock network, be likely to result in active and standby without being found failure, failure
Network instruction is inconsistent, in turn results in the confusion of clock renewal.
The content of the invention
In order to improve the security of substation network clock, solve Novel intelligent substation communication setting network and attacked
When defense mechanism imperfection, tackle man-in-the-middle attack situation, the present invention provide it is a kind of based on passback detection transformer substation communication
Network and its time synchronized safety method.
Network includes：Optical network unit ONU, synchronous optical line terminal OLT and EPON protocol processors；Wherein, Mei Geguang
NE ONU interface module has two interfaces to have identical state forever, and substation network is superfluous using active and standby link
Remaining configuration mode.
The network is the double star intelligent substation network set up using passive optical network technique PON, PON up-downgoing
Data transfer uses single fiber wavelength-division multiplex technique, and redundant configuration mode uses Parallel Redundancy Protocol PRP.
Method includes：
Timestamp is passed to each optical network unit by step 1, the EPON protocol processors of intelligent substation network
ONU；
Round-trip delay RTT is calculated after step 2, optical network unit ONU time of receipt (T of R) stamp, and is sent simultaneously from active and standby link
Message and the local time information that will update are to synchronous optical line terminal OLT；
Step 3, synchronous optical line terminal OLT determine whether security risk occur, if it is determined that there is security risk, then terminate
The time synchronized of optical network unit ONU side；
Step 4, if it is determined that do not occur security risk, then optical network unit ONU tracks any time all the way in active and standby link
Stamp.
The synchronous optical line terminal OLT determines whether that the foundation for security risk occur is：If synchronous optical line terminal
The round-trip delay RTT values of the active and standby link calculation in OLT sides differ by more than setting value and or receive feedback optical network unit ONU will
The local time information inconsistency to be updated, decides that security risk occur.
Methods described also includes：Optical network unit ONU receives message every time can all update local zone time and monitor change feelings
Condition, synchronous optical line terminal OLT receives the change that message can all update and monitor round-trip delay RTT every time；Optical network unit ONU
Timestamp information, round-trip delay RTT values and the optical network unit ONU sheet of the synchronous optical line terminal OLT carried according to message
The timer on ground can be calculated and renewal time.
The EPON protocol processors are stabbed by internal Multi-point Control Protocol message passing time.
The timestamp is the timestamp based on IEEE1588 agreements.
The round-trip delay RTT calculates acquisition by using the distance measurement function in Multi-point Control Protocol, specific as follows：
Synchronous optical line terminal OLT is in T0Moment sends in DISCOVER GATE frames, this control frame and carries time stamp T0, warp
Downlink transfer time delay Tdownstream, optical network unit ONU receives and temporal information is parsed after DISCOVER GATE frames, and incite somebody to action this
The ground time is updated to T0, processing wait time delay is Twait, then optical network unit ONU is in T1Moment sends REGISTER_REQ frames
As return information, through uplink time delay Tupstream, synchronous optical line terminal OLT is in T2Reception is to this frame, entirely
Pair when time delay be Treponse, then round-trip delay RTT value be：
RTT=Treponse-Twait=(T2-T0)-(T1-T0)=T2-T1。
The beneficial effects of the present invention are：New Generation of Intelligent transformer station is the center switch using center switch as core
In units of PON ports, EPON is constituted by optical cable and photo-coupler and connects many subnets that partner, in go-between
Under attack mode, by increasing the testing mechanism of OLT sides, allow ONU to send feedback message on active and standby network simultaneously and recalculate
RTT values, and the local time information that ONU will update is carried, and the temporal information obtained to OLT sides carries out judging whether to deposit
In security risk, confusion when being caused with preventing a-road-through communication network from being controlled pair further strengthens Novel intelligent substation
The security and robustness of communication network.
Brief description of the drawings
Fig. 1 is RTT ranging process schematic diagrames.
Fig. 2 is the delay value schematic diagram for adding intermediate equipment.
Fig. 3 is man-in-the-middle attack design sketch.
Embodiment
Below in conjunction with the accompanying drawings, embodiment is elaborated.
The present invention introduces passive optical network technique PON on the basis of intelligent substation network, sets up topological structure letter
Single, reliable double star network structure, PON up-downgoing data transfer uses single fiber wavelength-division multiplex technique, can largely subtract
The complexity of few transformer station fiber optic network, further improves the reliability of network；Substation communication network based on PTN interchangers
In, for the reliability of the clock network that further improves transformer station, using Parallel Redundancy Protocol (PRP) mode of standard, often
Individual ONU interface modules have two interfaces to have identical state forever, and substation network uses the redundant configuration side of active and standby network
Formula, when PRP is run, the highest master clock of clock source connection is connected respectively on active and standby network core interchanger, when primary
It can be seamlessly switched on standby clock device during clock plant failure, the clock sync message that master clock is sent is selected in active and standby net
Two-way is concurrent on network, active release digging soil formula；Novel intelligent substation EPON system is the system of a time synchronized, each
ONU can track OLT clock source.ONU reach the standard grade registration process be exactly time synchronized process.EPON protocol processors pass through
Internal MPCP (Multi-Point Control Protocol, Multi-point Control Protocol) message passes to IEEE1588 timestamps
Each ONU, ONU receive 1588 timestamp post-compensation round-trip delay RTT (Round-Trip Time), when generating the 1588 of ONU
Between stab, the timestamp is synchronous with 1588 clock sources.
The present invention calculates round-trip delay RTT using the distance measurement function in Multi-point Control Protocol：
Time between synchronous OLT and ONU uses the distance measurement function in EPON MPCP agreements, i.e., using OLT and ONU it
Between MPCP messages.The purpose of ONU rangings is the up transmission time with the ONU for measuring RTT values control different distance to ensure
Do not conflict from the ONU data for being sent to OLT.
ONU first ranging process as shown in figure 1, OLT is in T0Moment sends in DISCOVER GATE frames, this control frame and taken
Band time stamp T0(MPCP timestamps timer is T0), receive DISCOVER through downlink transfer time delay Tdownstream, ONU
Temporal information is parsed after GATE frames, and local zone time is updated to T0, processing wait time delay is Twait, and then ONU is in T1Moment
REGISTER_REQ frames are sent as return information, through uplink time delay Tupstream, OLT is in T2Reception to this frame,
Time delay is Treponse at whole pair, then RTT value is：
RTT=Treponse-Twait=(T2-T0)-(T1-T0)=T2-T1
Under the normal operating conditions after the completion of registration, ONU receives MPCP messages every time can all update local zone time and supervise
Depending on situation of change (timedrift), it is ensured that ONU work clock tracks OLT tranmitting data register.
The present invention uses PRP Parallel Redundancy Protocol renewal time information：
Each equipment has two PON mouthfuls of transmitted in parallel data, and selectivity is received, while having active and standby net to increase network
Reliability.In principle, 1588 timestamps that ONU synchronously gets off from double-PON port are essentially identical (error are in tens nanoseconds).When
In the case of two PON mouthfuls of optical links are all normal, as long as ONU arbitrarily tracking 1588 timestamp all the way.After the completion of registration
Normal condition under, ONU receives MPCP messages every time can all update local zone time and monitor situation of change, and OLT is received every time
MPCP messages can all update and monitor RTT change.The OLT that ONU is carried according to MPCP messages timestamp information, RTT values with
And the local timers of ONU can calculate and update for 1588 times.
Analyze man-in-the-middle attack mode：
There is the timestamp information that intermediate equipment obtains MPCP messages OLT at the middle and upper levels, and OLT clock sections in man-in-the-middle attack
Point essential information (IP, MAC etc.), and the ONU equipment of subordinate is transmitted to, at normal pair in the cycle, intermediate equipment intercepts and captures OLT
Time synchronized MPCP messages between equipment and ONU equipment, go-between's equipment for OLT equivalent to from clock status, under
Layer ONU is equivalent to master clock state.
Man-in-the-middle attack node can be sent to ONU temporal information value by changing, and carry out any change and send MPCP messages
To ONU time, and then manipulate link RTT value, this also imply that attacker can arbitrarily manipulate ONU nodes it is real-time when
Clock, the ONU clock nodes equipment can be made progressively to deviate the real-time clocks of OLT node devices can not without being found failure, failure
It is found also be switched standby clock network, it is inconsistent to be likely to result in active and standby network instruction, in turn results in clock more
New confusion.
Adoptable settlement mechanism：
Intermediate equipment time synchronization process：Intermediate equipment sends MPCP messages to OLT sides, the RTT values that OLT sides are calculated,
As shown in ETE rtt in Fig. 2, the calculating of OLT sides obtains rational RTT values and is transferred to ONU sides.Intermediate equipment copy package is simultaneously sent
MPCP messages reach the time of ONU sides, as shown in Delay in Fig. 2, Delay values record go-between create the carrying of MPCP bags when
Between the value of information, for ONU update local zone time.Timestamp that ONU is transmitted according to OLT and RTT values are accurately obtained
1588 temporal informations.
The security risk of presence：
OLT sides can receive the RTT values of deception without giving a warning, ONU sides can arbitrarily change MPCP carrying when
Between stamp information come disturb ONU sides pair when, as shown in Delay in Fig. 3, go-between only obtains and forwards MPCP messages, it is impossible to send out
Now attack.
In the present invention, it is in OLT sides increase passback testing mechanism, i.e., to be emulated according to Fig. 3 to improve time synchronized safety method
Attack effect, increase OLT testing mechanisms.Comprise the following steps that：
(1) ONU is allowed from primary link and reserve link and sends message while feeding back and recalculates RTT values, and carries ONU
The local time information that will be updated；
(2) increase contrasting detection mechanism in OLT sides, judge that the ONU that the RTT values and ONU of active and standby link calculation are fed back will
The uniformity for the local time information to be updated, if the RTT values of the active and standby link calculation in OLT sides have big difference or received anti-
The local time information inconsistency that the ONU of feedback will update, decides that security risk occur, so as to terminate the time of ONU sides
Synchronous, the chaotic equipment to transformer station is damaged when preventing ONU sides pair.
The New Generation of Intelligent transformer station of the present invention is that, using center switch as core, center switch is using PON ports to be single
Position, constitutes EPON by optical cable and photo-coupler and connects many subnets that partner, under man-in-the-middle attack pattern, lead to
The testing mechanism of increase OLT sides is crossed, allows ONU to send feedback report messages on active and standby network simultaneously and recalculates RTT values,
And the local time information that ONU will update is carried, and the temporal information obtained to OLT sides carries out judging whether safety
Risk, confusion when being caused with preventing a-road-through communication network from being controlled pair further strengthens Novel intelligent substation communication network
The security and robustness of network.
Above-described embodiment is only the present invention preferably embodiment, but protection scope of the present invention is not limited to
This, any one skilled in the art the invention discloses technical scope in, the change that can readily occur in or replace
Change, should all be included within the scope of the present invention.Therefore, protection scope of the present invention should be with the protection model of claim
Enclose and be defined.
Claims (8)
1. a kind of substation communication network based on passback detection, it is characterised in that including：Optical network unit ONU, synchronous light
Road terminal OLT and EPON protocol processor；Wherein, the interface module of each optical network unit ONU has two interfaces to have forever
Identical state, substation network uses the redundant configuration mode of active and standby link.
2. network according to claim 1, it is characterised in that described is the double star set up using passive optical network technique PON
Shape intelligent substation network, PON up-downgoing data transfer uses single fiber wavelength-division multiplex technique, and redundant configuration mode is using simultaneously
Row redundancy protocol PRP.
3. a kind of time synchronized safety method based on substation communication network described in claim 1, it is characterised in that including：
Timestamp is passed to each optical network unit ONU by step 1, the EPON protocol processors of intelligent substation network；
Round-trip delay RTT is calculated after step 2, optical network unit ONU time of receipt (T of R) stamp, and message is sent simultaneously from active and standby link
And the local time information that will be updated is to synchronous optical line terminal OLT；
Step 3, synchronous optical line terminal OLT determine whether security risk occur, if it is determined that there is security risk, then terminate light net
The time synchronized of network unit ONU side；
Step 4, if it is determined that do not occur security risk, then optical network unit ONU tracks any timestamp all the way in active and standby link.
4. method according to claim 3, it is characterised in that the synchronous optical line terminal OLT determines whether safety occur
The foundation of risk is：If the round-trip delay RTT values of the active and standby link calculation in synchronous optical line terminal OLT side differ by more than setting
Value and or receive the local time information inconsistency that the optical network unit ONU of feedback will update, decide that safety wind occur
Danger.
5. method according to claim 3, it is characterised in that methods described also includes：Optical network unit ONU receives report every time
Wen Douhui updates local zone time and monitors situation of change, and synchronous optical line terminal OLT receives message every time can all update and monitor
Round-trip delay RTT change；It is the timestamp information for the synchronous optical line terminal OLT that optical network unit ONU is carried according to message, past
Returning time delay RTT values and the local timer of optical network unit ONU can calculate and renewal time.
6. method according to claim 3, it is characterised in that the EPON protocol processors pass through internal Multi-point Control Protocol
Message passing time is stabbed.
7. method according to claim 3, it is characterised in that the timestamp is the timestamp based on IEEE1588 agreements.
8. method according to claim 3, it is characterised in that the round-trip delay RTT is by using in Multi-point Control Protocol
Distance measurement function calculate acquisition, it is specific as follows：
Synchronous optical line terminal OLT is in T0Moment sends in DISCOVER GATE frames, this control frame and carries time stamp T0, through descending
Propagation delay time Tdownstream, optical network unit ONU, which is received, parses temporal information after DISCOVER GATE frames, and when will be local
Between be updated to T0, processing wait time delay is Twait, then optical network unit ONU is in T1Moment sends REGISTER_REQ frame conducts
Return information, through uplink time delay Tupstream, synchronous optical line terminal OLT is in T2Reception is to this frame, at whole pair
Time delay is Treponse, then round-trip delay RTT value be：
RTT=Treponse-Twait=(T2-T0)-(T1-T0)=T2-T1。
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107612650A (en) * | 2017-08-10 | 2018-01-19 | 国家电网公司 | Message processing method and system |
| CN111788800A (en) * | 2018-07-27 | 2020-10-16 | 松下电器（美国）知识产权公司 | Frame transmission method and secure star coupler |
| CN111787013A (en) * | 2020-07-03 | 2020-10-16 | 中国电子科技集团公司第三十研究所 | Attack monitoring device and method of optical fiber time synchronization system |
| CN116112144A (en) * | 2022-12-22 | 2023-05-12 | 四川九洲电器集团有限责任公司 | Self-adaptive delay compensation synchronous transmission method for signal level data of optical fiber network |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6848053B1 (en) * | 1999-04-16 | 2005-01-25 | Fujitsu Limited | Optical network unit and optical line terminal |
| CN1638341A (en) * | 2004-01-02 | 2005-07-13 | 三星电子株式会社 | Bi-directional wavelength division multiplexing self-healing passive optical network |
| CN101431385A (en) * | 2008-08-26 | 2009-05-13 | 中兴通讯股份有限公司 | Frequency and time synchronization method for passive optical network |
| CN101895791A (en) * | 2009-05-21 | 2010-11-24 | 中兴通讯股份有限公司 | Protection switching method and device in Ethernet passive optical network |
| CN202634436U (en) * | 2012-03-22 | 2012-12-26 | 绍兴电力局 | Passive optical network communication system with uplink and downlink ports possessing complete self-healing protection function |
-
2017
- 2017-05-16 CN CN201710342390.4A patent/CN106982397B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6848053B1 (en) * | 1999-04-16 | 2005-01-25 | Fujitsu Limited | Optical network unit and optical line terminal |
| CN1638341A (en) * | 2004-01-02 | 2005-07-13 | 三星电子株式会社 | Bi-directional wavelength division multiplexing self-healing passive optical network |
| CN101431385A (en) * | 2008-08-26 | 2009-05-13 | 中兴通讯股份有限公司 | Frequency and time synchronization method for passive optical network |
| CN101895791A (en) * | 2009-05-21 | 2010-11-24 | 中兴通讯股份有限公司 | Protection switching method and device in Ethernet passive optical network |
| CN202634436U (en) * | 2012-03-22 | 2012-12-26 | 绍兴电力局 | Passive optical network communication system with uplink and downlink ports possessing complete self-healing protection function |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107612650A (en) * | 2017-08-10 | 2018-01-19 | 国家电网公司 | Message processing method and system |
| CN107612650B (en) * | 2017-08-10 | 2019-04-09 | 国家电网公司 | Message processing method and system |
| CN111788800A (en) * | 2018-07-27 | 2020-10-16 | 松下电器（美国）知识产权公司 | Frame transmission method and secure star coupler |
| CN111788800B (en) * | 2018-07-27 | 2022-05-10 | 松下电器（美国）知识产权公司 | Frame transmission method and secure star coupler |
| CN111787013A (en) * | 2020-07-03 | 2020-10-16 | 中国电子科技集团公司第三十研究所 | Attack monitoring device and method of optical fiber time synchronization system |
| CN111787013B (en) * | 2020-07-03 | 2022-02-25 | 中国电子科技集团公司第三十研究所 | Attack monitoring device and method of optical fiber time synchronization system |
| CN116112144A (en) * | 2022-12-22 | 2023-05-12 | 四川九洲电器集团有限责任公司 | Self-adaptive delay compensation synchronous transmission method for signal level data of optical fiber network |
| CN116112144B (en) * | 2022-12-22 | 2024-04-09 | 四川九洲电器集团有限责任公司 | Self-adaptive delay compensation synchronous transmission method for signal level data of optical fiber network |
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| CN106982397B (en) | 2020-06-16 |
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