DETAILED ACTION
Notice of AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
The priority document(s), which have been placed on record in the file, are acknowledged.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 11/19/2024 and 03/23/2026 are acknowledged.
Drawings
The drawings are objected to for the following reasons: Figures 1A and 1B should be designated by a legend such as --Prior Art—because they are respectively Figures 27 and 28 in the prior art, IEEE Std 1588™-2008, "IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems," IEEE Instrumentation and Measurement Society, 24 July 2008. See MPEP § 608.02(g). Corrected drawings in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. The replacement sheet(s) should be labeled “Replacement Sheet” in the page header (as per 37 CFR 1.84(c)) so as not to obstruct any portion of the drawing figures. If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Rejections - 35 USC § 101
Claim 19 is rejected under 35 U.S.C. 101 because the claimed invention is directed to non-statutory subject matter. The claim does not fall within at least of the four categories of patent eligible subject matter because the broadest reasonable interpretation of the limitation, "A computer readable storage medium storing thereon instructions which when executed by at least one processor, cause the at least one processor to perform steps" in Lines [1-2] of claim 19 encompasses signals per se. In Para. [0029] of the specification, the instant application recites, “a computer readable storage medium,” which clearly includes propagating electromagnetic waves. The further recitation of “instructions” in claim 19 only serves to limit the content carried by the electromagnetic waves. As understood in light of the specification, the broadest reasonable interpretation of claim 19 encompasses signals which are not within one of the four statutory categories of invention. See MPEP 2106.03 I. It is suggested that claim 19 be amended to recite a “non-transitory” computer readable medium to overcome this rejection.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.-The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-19 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Claim 1 (and similarly claim 10 and 19) recites the limitation "second state where the PTP clock source is restored after a predetermined restoration time." However, there is insufficient antecedent basis for this limitation in the claim because there is no PTP clock source that needs restoration – only the reception of an announce message was interrupted. Therefore, it is unclear if the referenced interruption means the the PTP clock source completely stops sending announce message. On the other hand, Para. [0008] of the instant specification recites, “… reception of an announce message from a precision time protocol (PTP) clock source is interrupted due to a local change at the network device, and a second state where the PTP clock source is restored after a predetermined restoration time, or the reception of the announce message from the PTP clock source is recovered after the local change.” Hence, for examination purposes the limitation, the interruption of the reception of the announce message has been construed to be due to a change in the network device which affects the device’s ability to receive subsequent announce messages. The office respectfully requests the applicant to amend the claim(s) in order to clarify the claimed invention.
Dependent claims (2-9 and 11-19) not addressed above are rejected under the same rational as the parent claim due to a failure to resolve the deficiencies of the parent claim discussed above.
Claim 2 (and similarly claim 11) recites the limitation "when determining that the network device is not in one of the first state and the second state, using the PTP clock source as a candidate PTP master after the PTP clock source is restored based on the predetermined restoration time." However, the phrase “network device is not in … the second state” and the phrase, “after the PTP clock source is restored based on the predetermined restoration time” makes the cited limitation contradictory and unclear since claim 1 defines the second state as where the reception of the announce message from the PTP clock source is recovered after the local change. On the other hand, Para. [0008-0010] of the instant specification, “…using the PTP clock source as a candidate PTP master, without waiting for the predetermined restoration time … using the PTP clock source as a candidate PTP master after the PTP clock source is restored based on the predetermined restoration time.” Hence, for examination purposes, the above referenced limitation of claim 2 and 11, has been construed to mean the PTP clock source is used as candidate PTP master before and after the restoration time elapses. The office respectfully requests the applicant to amend the claim(s) in order to clarify the claimed invention.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-4, 7, 10-13, 16, 19 are rejected under 35 U.S.C. 103 as being unpatentable over ZHANG et al. (CN 101252426 B), hereinafter referenced as Zhang, in view of Yang et al. (US 20160156427 A1), hereinafter referenced as Yang.
Regarding claims 1, 10 and 19, Zhang teaches a method performed by a network device (Fig. 1, Para. [0010]-Zhang discloses a concept of precise synchronous clock in the industrial switch, a switch can receive real-time clock of the external clock source or local machine as the main clock of the network. other network nodes in the network synchronous clock of high level in the network. Para. [0005-0007]-Zhang discloses network realization method of network time in the network synchronous state of lower, each device according to a configuration of the time domain in turn in its own time domain the network maintenance. avoids the main station fails in the ring type network, generating network storm, also defines the network is changed, reporting mechanism failure, reporting the following network fault can be located in the network link failure, link is normal, the error of the CPU, the program fault, and the fault of the network to accurately locate), comprising:
determining whether the network device is in one of a first state where a reception of an announce message from a precision time protocol (PTP) clock source is interrupted due to a local change at the network device (Para. [0071-0076]-Zhang discloses fault device recovery. Para. [0089-0093]-Zhang discloses damage device recovery ... after the fault device recovery. Para. [0054-0056]-Zhang discloses when periodic message sent in the network during the ring link is interrupted, then link interrupt adjacent two network reporting link fault message, the message with the highest priority … other net element in the network after receiving the link fault message, the original BLOCKED state of the port migration to a FORWARDING state while renovating the FDB table of each network node ... network link termination node, the link port of the interrupt transfer to the BLOCKED state from the original FORWARDING state. Claim [1]-Zhang discloses when periodic message sent in the network during the ring link is interrupted, then link interrupt adjacent two network reporting link fault message. the message with the highest priority, the network element of the network link is interrupted, interruption of the link port from the original FORWARDING state transfers to the BLOCKED state, the realizing method of distributed redundancy ring network, after the change in network topology. precise synchronous path of the network will automatically update to the highest precision clock source, the realizing method of distributed redundancy ring network, after the fault device restoring the adjacent two switch again back to the network, the direct connection is in the BLOCKED state. two ends of recovery after the device is in BLOCKED state, the distributed redundancy ring network implementing method can clearly obtaining the current network topology and connection relation on the each element. (See also Para. [0011])), and
the reception of the announce message from the PTP clock source is recovered after the local change (Claim [1]-Zhang discloses when periodic message sent in the network during the ring link is interrupted, then link interrupt adjacent two network reporting link fault message. the message with the highest priority, the network element of the network link is interrupted, interruption of the link port from the original FORWARDING state transfers to the BLOCKED state, the realizing method of distributed redundancy ring network, after the change in network topology. precise synchronous path of the network will automatically update to the highest precision clock source, the realizing method of distributed redundancy ring network, after the fault device restoring the adjacent two switch again back to the network, the direct connection is in the BLOCKED state. two ends of recovery after the device is in BLOCKED state, the distributed redundancy ring network implementing method can clearly obtaining the current network topology and connection relation on the each element. Para. [0073-0076]-Zhang discloses CPU fault device restoring … after the fault device recovery, two adjacent switch back to the network again, this is in BLOCKED state, two port resumes after the device is in BLOCKED state … after the fault recovery, the device other device in the network for synchronization, clock, enable period detection. Para. [0089-0093]-Zhang discloses damage device recovery ... after the fault device recovery, two adjacent switch back to the network again, this is in BLOCKED state, two port resumes after the device is in BLOCKED state ... after the fault recovery, firstly, the switch other device in the network for synchronization, clock, enable period detection. (See also Para. [0007])); and
when determining that the network device is in one of the first state and the second state, using the PTP clock source as a candidate PTP master, without waiting for the predetermined restoration time (Para. [0008]-Zhang discloses system support the precise clock protocol, automatically receiving the external clock source of the clock signal, and can make other network element in the network to main clock source is synchronously, synchronization precision is highest can reach hundreds of ns level. system support the precise clock protocol, can set a real-time clock of a certain network element in the network is the main clock in network, and can make other network elements in the network synchronized on the main clock source. all network elements in a precise real-time clock and provides history record each element can accurately record the network event happened in, and it can exactly realize the fault precise location).
Zhang fails to explicitly teach a second state where the PTP clock source is restored after a predetermined restoration time.
However, Yang teaches a second state where the PTP clock source is restored after a predetermined restoration time (Para. [0010]-Yang discloses by switching to a backup master clock node upon detection of synchronization loss and propagating the MR message to the affected network nodes, the clock source may be quickly located and the clock may be recovered in a short time period. Para. [0031]-Yang discloses the node 106 can obtain the reference clock from the node 101 since the node 101 is the master clock node connected to the PRC ... the clock is then distributed from the master clock node 101 to the nodes 106, 105 and 104 according to the PTP or SyncE, and the clock synchronization is restored in the network 100. By switching to a backup master clock node and propagating the MR message among backup master clock nodes upon detection of loss of synchronization due to e.g. network topology change or link/node failure, the clock source may be located in a relatively short time period. The time for restoring synchronization of the network may be significantly reduced. Para. [0005]-Yang discloses PTP port in the PTP hierarchy uses its slow Announce message, which is typically 1 packet in 2 seconds, to detect a synchronization loss {Corresponding to determining the synchronization state of the node}).
Zhang and Yang are both considered to be analogous to the claimed invention because they are in the same field of communication network, dealing with clock recovery.
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the Zhang to incorporate the teachings of Yang on PTP clock source, with a motivation to restore the clock after restoration time, and guarantee clock recovery in a node of a packet-based network which is synchronized with other nodes based on a master-slave clock mechanism, (Yang, Para. [0007]).
Regarding claims 2 and 11, Zhang teaches the method according to claim 1 and the network device according to claim 10 respectively,
Zhang fails to explicitly teach when determining that the network device is not in one of the first state and the second state, using the PTP clock source as a candidate PTP master after the PTP clock source is restored based on the predetermined restoration time.
However, Yang teaches when determining that the network device is not in one of the first state and the second state, using the PTP clock source as a candidate PTP master after the PTP clock source is restored based on the predetermined restoration time (Para. [0010]-Yang discloses by switching to a backup master clock node upon detection of synchronization loss and propagating the MR message to the affected network nodes, the clock source may be quickly located and the clock may be recovered in a short time period. Para. [0031]-Yang discloses the node 106 can obtain the reference clock from the node 101 since the node 101 is the master clock node connected to the PRC ... the clock is then distributed from the master clock node 101 to the nodes 106, 105 and 104 according to the PTP or SyncE, and the clock synchronization is restored in the network 100. By switching to a backup master clock node and propagating the MR message among backup master clock nodes upon detection of loss of synchronization due to e.g. network topology change or link/node failure, the clock source may be located in a relatively short time period. The time for restoring synchronization of the network may be significantly reduced. Para. [0005]-Yang discloses PTP port in the PTP hierarchy uses its slow Announce message, which is typically 1 packet in 2 seconds, to detect a synchronization loss {Corresponding to determining the synchronization state of the node}).
Yang is considered to be analogous because it is in the same field of communication network, dealing with clock recovery.
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the Zhang to incorporate the teachings of Yang on PTP clock source, with a motivation to for a candidate PTP master, and guarantee clock recovery in a node of a packet-based network which is synchronized with other nodes based on a master-slave clock mechanism, (Yang, Para. [0007]).
Regarding claims 3 and 12, Zhang teaches the method according to claim 1 and the network device according to claim 10 respectively,
Zhang further teaches whether the network device is in one of the first state and the second state is determined based on a state machine of the network device (Para. [0013]-Zhang discloses a precise clock is gradually transferring, when superior sending SYNC PDU message more than three times, the adjacent node does not respond Delay-Req information of PDU message, it is judged that the error of the CPU of the network node and the network state migration, network enters from the closed ring state. in the network port in BLOCKED state transfers to the FORWARDING state, fault switch adjacent ports of two network connected with the fault switch the transfer to the BLOCKED state from the original FORWARDING state); and
the state machine is configured to switch between the first state (Para. [0071-0076]-Zhang discloses fault device recovery. Para. [0089-0093]-Zhang discloses damage device recovery ... after the fault device recovery. Para. [0054-0056]-Zhang discloses when periodic message sent in the network during the ring link is interrupted, then link interrupt adjacent two network reporting link fault message, the message with the highest priority … other net element in the network after receiving the link fault message, the original BLOCKED state of the port migration to a FORWARDING state while renovating the FDB table of each network node ... network link termination node, the link port of the interrupt transfer to the BLOCKED state from the original FORWARDING state. Claim [1]-Zhang discloses when periodic message sent in the network during the ring link is interrupted, then link interrupt adjacent two network reporting link fault message. the message with the highest priority, the network element of the network link is interrupted, interruption of the link port from the original FORWARDING state transfers to the BLOCKED state, the realizing method of distributed redundancy ring network, after the change in network topology. precise synchronous path of the network will automatically update to the highest precision clock source, the realizing method of distributed redundancy ring network, after the fault device restoring the adjacent two switch again back to the network, the direct connection is in the BLOCKED state. two ends of recovery after the device is in BLOCKED state, the distributed redundancy ring network implementing method can clearly obtaining the current network topology and connection relation on the each element. (See also Para. [0011])),
the second state (Claim [1]-Zhang discloses when periodic message sent in the network during the ring link is interrupted, then link interrupt adjacent two network reporting link fault message. the message with the highest priority, the network element of the network link is interrupted, interruption of the link port from the original FORWARDING state transfers to the BLOCKED state, the realizing method of distributed redundancy ring network, after the change in network topology. precise synchronous path of the network will automatically update to the highest precision clock source, the realizing method of distributed redundancy ring network, after the fault device restoring the adjacent two switch again back to the network, the direct connection is in the BLOCKED state. two ends of recovery after the device is in BLOCKED state, the distributed redundancy ring network implementing method can clearly obtaining the current network topology and connection relation on the each element. Para. [0073-0076]-Zhang discloses CPU fault device restoring … after the fault device recovery, two adjacent switch back to the network again, this is in BLOCKED state, two port resumes after the device is in BLOCKED state … after the fault recovery, the device other device in the network for synchronization, clock, enable period detection. Para. [0089-0093]-Zhang discloses damage device recovery ... after the fault device recovery, two adjacent switch back to the network again, this is in BLOCKED state, two port resumes after the device is in BLOCKED state ... after the fault recovery, firstly, the switch other device in the network for synchronization, clock, enable period detection. (See also Para. [0007])), and
a third state where the reception of the announce message from the PTP clock source is interrupted due to an external change that is external to the network device (Para. [0007]-Zhang discloses distributed redundancy ring network realization method of network time in the network synchronous state of lower, each device according to a configuration of the time domain in turn in its own time domain the network maintenance. avoids the main station fails in the ring type network, generating network storm, also defines the network is changed, reporting mechanism failure, reporting the following network fault can be located in the network link failure, link is normal, the error of the CPU, the program fault, and the fault of the network to accurately locate. Para. [0048-0066]-Zhang discloses 1.2 link fault detection ... ring closing-opening ... network link termination node, the link port of the interrupt transfer to the BLOCKED state from the original FORWARDING state. Para. [0067-0077]-Zhang discloses 1.3 CPU fault detection ... Fault detection method precision synchronous clock message is sent in a certain period of time according to the received condition of fine clock message to judge whether the CPU of the switch is in fault state ... fault device adjacent port of two network elements, immediately lower from FORWARDING state transfers to the BLOCKED state. Para. [0078-0095]-Zhang discloses 1.4 whole device failure detection and recovery ... a device power down ... Fault detection method precision synchronous clock message is sent in a certain period of time according to the received condition of fine clock message to judge whether the CPU of the switch is in fault state ... fault device adjacent port of two network elements, immediately lower from FORWARDING state transfers to the BLOCKED state).
Zhang fails to explicitly teach a fourth state where the reception of the announce message from the PTP clock source is recovered but the predetermined restoration time has not elapsed.
However, Yang teaches a fourth state where the reception of the announce message from the PTP clock source is recovered but the predetermined restoration time has not elapsed (Para. [0010]-Yang discloses by switching to a backup master clock node upon detection of synchronization loss and propagating the MR message to the affected network nodes, the clock source may be quickly located and the clock may be recovered in a short time period. Para. [0031]-Yang discloses the node 106 can obtain the reference clock from the node 101 since the node 101 is the master clock node connected to the PRC ... the clock is then distributed from the master clock node 101 to the nodes 106, 105 and 104 according to the PTP or SyncE, and the clock synchronization is restored in the network 100. By switching to a backup master clock node and propagating the MR message among backup master clock nodes upon detection of loss of synchronization due to e.g. network topology change or link/node failure, the clock source may be located in a relatively short time period. The time for restoring synchronization of the network may be significantly reduced. Para. [0005]-Yang discloses PTP port in the PTP hierarchy uses its slow Announce message, which is typically 1 packet in 2 seconds, to detect a synchronization loss {Corresponding to determining the synchronization state of the node}).
Yang is considered to be analogous because it is in the same field of communication network, dealing with clock recovery.
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the Zhang to incorporate the teachings of Yang on PTP clock source, with a motivation to for the recovery of the reception of announce message, and guarantee clock recovery in a node of a packet-based network which is synchronized with other nodes based on a master-slave clock mechanism, (Yang, Para. [0007]).
Regarding claims 4 and 13, Zhang teaches the method according to claim 3 and the network device according to claim 12 respectively,
Zhang fails to explicitly teach the state machine has a parameter indicating, for the fourth state, remaining time required for restoring the PTP clock source; and wherein the parameter takes a value that equals the predetermined restoration time when the fourth state is entered, and decreases with time.
However, Yang teaches the state machine has a parameter indicating, for the fourth state, remaining time required for restoring the PTP clock source (Para. [0035]-Yang disclosest the master-slave clock mechanism may include a time related synchronization protocol and a frequency related synchronization protocol. The time related synchronization protocol may be PTP, and the master clock node reselection message may include an ESMC event message which uses a first reserved bit indicating the reselection and padding octets indicating port identity of the node); and
the parameter takes a value that equals the predetermined restoration time when the fourth state is entered, and decreases with time (Para. [0010]-Yang discloses by switching to a backup master clock node upon detection of synchronization loss and propagating the MR message to the affected network nodes, the clock source may be quickly located and the clock may be recovered in a short time period. Para. [0031]-Yang discloses the node 106 can obtain the reference clock from the node 101 since the node 101 is the master clock node connected to the PRC ... the clock is then distributed from the master clock node 101 to the nodes 106, 105 and 104 according to the PTP or SyncE, and the clock synchronization is restored in the network 100. By switching to a backup master clock node and propagating the MR message among backup master clock nodes upon detection of loss of synchronization due to e.g. network topology change or link/node failure, the clock source may be located in a relatively short time period. The time for restoring synchronization of the network may be significantly reduced. Para. [0005]-Yang discloses PTP port in the PTP hierarchy uses its slow Announce message, which is typically 1 packet in 2 seconds, to detect a synchronization loss {Corresponding to determining the synchronization state of the node}).
Yang is considered to be analogous because it is in the same field of communication network, dealing with clock recovery.
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the Zhang to incorporate the teachings of Yang on PTP clock source, with a motivation to for a parametric restoration time, and guarantee clock recovery in a node of a packet-based network which is synchronized with other nodes based on a master-slave clock mechanism, (Yang, Para. [0007]).
Regarding claims 7 and 16, Zhang in view of Yang teaches the method according to claim 1 and the network device according to claim 10 respectively,
Zhang further teaches the local change comprises one or more of: the network device being reloaded; a line card of the network device being reloaded; a process related to PTP in the network device being restarted; a configuration of a PTP port of the network device being changed; and a configuration of a PTP clock of the network device being changed (Para. [0075]-Zhang discloses newly added device and two adjacent device; there are three device, will start an initialization process to determine which device the port BLOCKED, and other two device all the ring ports to the FORWARDING state. Para. [0048-0066]-Zhang discloses 1.2 link fault detection ... ring closing-opening ... network link termination node, the link port of the interrupt transfer to the BLOCKED state from the original FORWARDING state. Para. [0067-0077]-Zhang discloses 1.3 CPU fault detection ... Fault detection method precision synchronous clock message is sent in a certain period of time according to the received condition of fine clock message to judge whether the CPU of the switch is in fault state ... fault device adjacent port of two network elements, immediately lower from FORWARDING state transfers to the BLOCKED state. Para. [0078-0095]-Zhang discloses 1.4 whole device failure detection and recovery ... a device power down ... Fault detection method precision synchronous clock message is sent in a certain period of time according to the received condition of fine clock message to judge whether the CPU of the switch is in fault state ... fault device adjacent port of two network elements, immediately lower from FORWARDING state transfers to the BLOCKED state).
Claims 5-6, 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over ZHANG et al. (CN 101252426 B), hereinafter referenced as Zhang, in view of Yang et al. (US 20160156427 A1), hereinafter referenced as Yang, and further in view of Rudi FRENZEL (US 20110216816 A1), hereinafter referenced as Frenzel.
Regarding claims 5 and 14, Zhang in view of Yang teaches the method according to claim 1 and the network device according to claim 10 respectively,
Zhang further teaches determining whether the network device is in one of the first state and the second state comprises: when the reception of the announce message from the PTP clock source is recovered after it is interrupted (Claim [1]-Zhang discloses when periodic message sent in the network during the ring link is interrupted, then link interrupt adjacent two network reporting link fault message. the message with the highest priority, the network element of the network link is interrupted, interruption of the link port from the original FORWARDING state transfers to the BLOCKED state, the realizing method of distributed redundancy ring network, after the change in network topology. precise synchronous path of the network will automatically update to the highest precision clock source, the realizing method of distributed redundancy ring network, after the fault device restoring the adjacent two switch again back to the network, the direct connection is in the BLOCKED state. two ends of recovery after the device is in BLOCKED state, the distributed redundancy ring network implementing method can clearly obtaining the current network topology and connection relation on the each element. Para. [0073-0076]-Zhang discloses CPU fault device restoring … after the fault device recovery, two adjacent switch back to the network again, this is in BLOCKED state, two port resumes after the device is in BLOCKED state … after the fault recovery, the device other device in the network for synchronization, clock, enable period detection. Para. [0089-0093]-Zhang discloses damage device recovery ... after the fault device recovery, two adjacent switch back to the network again, this is in BLOCKED state, two port resumes after the device is in BLOCKED state ... after the fault recovery, firstly, the switch other device in the network for synchronization, clock, enable period detection. (See also Para. [0007])).
Zhang fails to explicitly teach determining offsets between a clock of the network device and a clock of the PTP clock source for a predetermined time period, based on timestamps related to PTP messages communicated between the network device and the PTP clock source; and determining whether the network device is in the second state, based on the offsets determined in the predetermined time period.
However, Frenzel teaches determining offsets between a clock of the network device and a clock of the PTP clock source for a predetermined time period, based on timestamps related to PTP messages communicated between the network device and the PTP clock source (Para. [0043]-Frenzel discloses the receiver 218 may calculate offset and delay, which are used to synchronize the clock source 230 to the master clock source 214, in accordance with the following formulas: … Delay+Offset=timestamp 412 (T.sub.2)-timestamp 312 (T.sub.1) ... Offset=((T.sub.2-T.sub.1)-(T.sub.4-T.sub.3))/2 ... timestamp is generated at a TS.sub.N+K of a DMT symbol after a predetermined number K of time-domain samples. Para. [0058]-Frenzel discloses apparatus capable of implementing a state machine that is in turn capable of implementing the methodology described and illustrated herein may be used to implement the various communication methods, protocols and techniques according to the implementations); and
determining whether the network device is in the second state, based on the offsets determined in the predetermined time period (Para. [0043]-Frenzel discloses the receiver 218 may calculate offset and delay, which are used to synchronize the clock source 230 to the master clock source 214, in accordance with the following formulas: … Delay+Offset=timestamp 412 (T.sub.2)-timestamp 312 (T.sub.1) ... Offset=((T.sub.2-T.sub.1)-(T.sub.4-T.sub.3))/2 ... timestamp is generated at a TS.sub.N+K of a DMT symbol after a predetermined number K of time-domain samples. Para. [0058]-Frenzel discloses apparatus capable of implementing a state machine that is in turn capable of implementing the methodology described and illustrated herein may be used to implement the various communication methods, protocols and techniques according to the implementations).
Frenzel is considered to be analogous because it is in the same field of communication network, dealing with clock synchronization.
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the Zhang in view of Yang to incorporate the teachings of Frenzel on clock source, with a motivation to determine timestamp offset and the state of the device, and ensure time synchronization between the master and the slave nodes, (Frenzel, Para. [0002]).
Regarding claims 6 and 15, Zhang in view of Yang teaches the method according to claim 5 and the network device according to claim 14 respectively,
Zhang fails to explicitly teach the network device is determined to be in the second state when the offsets determined in the predetermined time period are within a predetermined range.
However, Frenzel teaches the network device is determined to be in the second state when the offsets determined in the predetermined time period are within a predetermined range (Para. [0043]-Frenzel discloses the receiver 218 may calculate offset and delay, which are used to synchronize the clock source 230 to the master clock source 214, in accordance with the following formulas: … Delay+Offset=timestamp 412 (T.sub.2)-timestamp 312 (T.sub.1) ... Offset=((T.sub.2-T.sub.1)-(T.sub.4-T.sub.3))/2 ... timestamp is generated at a TS.sub.N+K of a DMT symbol after a predetermined number K of time-domain samples. Para. [0058]-Frenzel discloses apparatus capable of implementing a state machine that is in turn capable of implementing the methodology described and illustrated herein may be used to implement the various communication methods, protocols and techniques according to the implementations).
Frenzel is considered to be analogous because it is in the same field of communication network, dealing with clock synchronization.
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the Zhang in view of Yang to incorporate the teachings of Frenzel on synchronization, with a motivation to determine the state of network device, and ensure time synchronization between the master and the slave nodes, (Frenzel, Para. [0002]).
Claims 8-9, 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over ZHANG et al. (CN 101252426 B), hereinafter referenced as Zhang, in view of Yang et al. (US 20160156427 A1), hereinafter referenced as Yang, and further in view of IEEE1588 (IEEE Std 1588™-2008), hereinafter referenced as IEEE1588.
Regarding claims 8 and 17, Zhang in view of Yang teaches the method according to claim 1 and the network device according to claim 10 respectively,
Zhang fails to explicitly teach using the PTP clock source as a candidate PTP master comprises: adding an announce message from the PTP clock source into a best master clock algorithm (BMCA) list.
However, IEEE1588 teaches using the PTP clock source as a candidate PTP master comprises: adding an announce message from the PTP clock source into a best master clock algorithm (BMCA) list (Page 30-31, Section [6.6.2]-IEEE1588 discloses within a domain, each port of an ordinary and boundary clock executes an independent copy of the protocol state machine. For "state decision events." each port examines the contents of all Announce messages received on the port. Using the best master clock algorithm, the Announce message contents and the contents of the data sets associated with the ordinary or boundary clock are analyzed to determine the state of each port of the clock ... Each port of an ordinary and boundary clock maintains a separate copy of the PTP state machine. This state machine defines the allowed states of the port and the transition rules between states. The principal "state decision events" determining the master-slave hierarchy are the receipt of an Announce message and the end of an announcelnterval (the interval between Announce messages). The best master clock algorithm compares data describing two clocks to determine which data describes the better clock).
IEEE1588 is considered to be analogous because it is in the same field of wireless communications, dealing with precision cloak synchronization protocol.
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the Zhang in view of Zhang to incorporate the teachings of IEEE1588 on PTP clock source, with a motivation to add announce message to BMCA list, and guarantee establishing a master-slave hierarchy, (IEEE1588, Page 30, Section 6.6.2.).
Regarding claims 9 and 18, Zhang in view of Yang teaches the method according to claim 1 and the network device according to claim 10 respectively,
Zhang fails to explicitly teach the network device is configured to act as one of: a boundary clock (BC); an ordinary clock (OC); and a transparent clock (TC).
However, IEEE1588 teaches the network device is configured to act as one of: a boundary clock (BC); an ordinary clock (OC); and a transparent clock (TC) (Fig. 9, Page 30-31, Section [6.6.2]-IEEE1588 discloses within a domain, each port of an ordinary and boundary clock executes an independent copy of the protocol state machine. For "state decision events." each port examines the contents of all Announce messages received on the port. Using the best master clock algorithm, the Announce message contents and the contents of the data sets associated with the ordinary or boundary clock are analyzed to determine the state of each port of the clock ... Each port of an ordinary and boundary clock maintains a separate copy of the PTP state machine. This state machine defines the allowed states of the port and the transition rules between states. The principal "state decision events" determining the master-slave hierarchy are the receipt of an Announce message and the end of an announcelnterval (the interval between Announce messages). The best master clock algorithm compares data describing two clocks to determine which data describes the better clock).
IEEE1588 is considered to be analogous because it is in the same field of wireless communications, dealing with precision cloak synchronization protocol.
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the Zhang in view of Zhang to incorporate the teachings of IEEE1588 on synchronization clock, with a motivation for boundary, ordinary or transparent clock, and guarantee establishing a master-slave hierarchy, (IEEE1588, Page 30, Section 6.6.2.).
Conclusion
Listed below are the prior arts made of record and not relied upon but are considered pertinent to applicant`s disclosure.
LIU et al. (WO 2015165192 A1)-discloses As shown in FIG. 5, in the actual time synchronization networking, the master device and the slave device that run the protocol No. 1588, that is, the PTP protocol, each master device provides a clock source through which the master device and the slave device communicate with each other. A link sends a PTP packet to the slave device. Therefore, one clock source corresponds to one link. The slave device (that is, the downstream device that needs to select the primary clock source) receives the announce message from multiple master devices (the upstream device that provides the clock source). The slave device runs the BMC algorithm from all the alternate clock sources. Choose the best one to synchronize as the primary clock source. Assume that the master device 1 initially selects the master device 1 as the master clock source, and synchronizes with the clock source through the cloud 1 communication link, and the link between the master device 1 and the slave device is recorded as the master-slave link ms-1. . If the cloud 1 communication link fails or the master device 1 fails, the slave device receives the sync packet from the master device 1 (the two-step method, and the follow-up packet), and the packet is lost. If the packet loss rate threshold is set, the clock source of the device is unstable. Therefore, the clock quality level information in the announcement packet corresponding to the master device 1 is changed to the specific value clock-class1 to trigger the BMC calculation on the device side. Reselect the master device 2 as the master clock source, and mark the original master-slave synchronization link ms-1 recorded from the device side as the slave-post state. If the packet received in the slave-post state is received, the packet loss rate is less than or equal to the set packet loss rate of the sync packet (the two-step method and the follow-up packet). The threshold value restores the clock value of the corresponding announce message recorded from the device to the original value, and removes the slave-post status flag of the ms-1 link. The slave device re-selects the primary clock source based on the BMC algorithm …. …Fig. 1-3
CHEN et al. (CN 102118780 A)-discloses C1, when the current clock source has fault, setting the switching timer, the duration of the switching timer can be set after the current clock source lock crystal chip can keep the normal clock function of time … C2, determining the fault of the current clock source is recovered in the switching timer, if restoration is continuously locked current time clock source, ending, if not recovered, continue to execute C3 ... C3. If the switch timer in the current clock source of the fault is not recovered, then determining the clock source than the current clock source low-priority is available and configured, if the low-priority of the clock source is available and configured, switching to the clock source of the lower priority …. …Fig. 1-2
Jake Araujo-Simon (US 20230421977 A1)-discloses ta precision time protocol (PTP) is used to synchronize clocks on the network. Specifically, the best master clock (BMC) algorithm is used to perform a distributed selection of the best clock amongst a number of candidate clocks on a network segment, based on criteria such as user-defined priority, and clock quality, which is measured in terms of clock variance and accuracy. A grandmaster clock is elected and used to determine the time base for the entire network, and so-called master clocks are made subsidiary to it, but are also used to determine the time base for other clocks, which are further subsidiary to them on each network segment, in a clock hierarchy .… …Fig. 1-5
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