DETAILED ACTION
This Action is in response to Applicant’s Response to Restriction Requirement and Preliminary Amendment filed on December 24, 2025. Claims 6-13 and 19-30 are now pending in the present application. This Action is made NON-FINAL.
Notice of Pre-AIA or 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
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Applicant’s claim for domestic priority under 35 U.S.C. 120 is acknowledged.
Information Disclosure Statement
The information disclosure statements submitted on September 24, 2024 and January 25, 2025 have been considered by the Examiner and made of record in the application file.
Preliminary Amendment
The present Office Action is based upon the original patent application filed on October 20, 2023 as modified by the preliminary amendments filed on January 23, 2024 and December 24, 2025. Claims 6-13 and 19-30 are now pending in the present application.
Drawings
The drawings are objected to because step 509 in figure 5A describes the first query response as Nbcf_get_response, however, paragraph 0121 of the specification describes this same first query response as Nbcf_Checkpoint_response. Appropriate correction of this discrepance is required.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office Action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended”. If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. 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. If a response to the present Office Action fails to include proper drawing corrections, corrected drawings or arguments therefor, the response can be held NON-RESPONSIVE and/or the application could be ABANDONED since the objections/corrections to the drawings are no longer held in abeyance.
Specification
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
The following title is suggested: METHOD AND DEVICE FOR SKIPPING AUTHENTICATION OF A TERMINAL DEVICE BASED ON TRUSTED DOMAIN ASSOCIATION BETWEEN PUBLIC NETWORK AND PRIVATE NETWORK CORE NETWORK ELEMENT DEVICES.
The disclosure is objected to because of the following informalities:
On line 2 of paragraph 0006, insert --a-- before “user”;
On line 1 of paragraph 0044, replace “(NPN)” with --(VPN)--;
On line 3 of paragraph 0085, the acronym BCDR needs to be spelled out; and
On line 6 of paragraph 0085, the acronym UDSF needs to be spelled out.
Appropriate correction is required.
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 (i.e., changing from AIA to pre-AIA ) 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, 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the Examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the Examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 6-12, 19-22, and 23-29 are rejected under 35 U.S.C. 103 as being unpatentable over Toor et al. (WO 2020/215272 A1, hereinafter “Toor”).
Citations refer to below are from the attached machine translation document of Toor et al.
Consider claim 6, Toor discloses a method, comprising:
receiving, by a first network element device in a public network core network, a first registration request sent by a terminal device, wherein the first registration request is a request of the terminal device to access a second network element device in a private network core network (see figure 7, S720–S730: the terminal initiates a registration request to the PLMN AMF (first network element device in a public network core network) requesting to connect to the NPN (private network core network); the PLMN AMF selects the corresponding NPN AMF (second network element device in the private network core network) according to information in the registration request (page 30 last paragraph to page 31 first paragraph));
sending, by the first network element device, a first query request to a third network element device in the public network core network (see figure 7, S740: the PLMN AMF verifies whether the NPN that the terminal is trying to connect to allows the terminal to directly access according to the local policy or query PLMN UDM (third network element device in the public network core network); the query to the PLMN UDM constitutes a first query request to a third network element device (page 31 second and third paragraphs); see also figure 6, S640 describing the analogous process: the NPN queries whether the identity of the PLMN that the terminal is trying to connect to is in the list of PLMN identities that the terminal is allowed to directly access (see page 28 fourth paragraph));
receiving, by the first network element device, a first query response from the third network element device (see figure 7, S740: the PLMN AMF receives a result from the query to the PLMN UDM indicating whether the NPN is in the list of networks that the terminal is allowed to directly access; the result of the query constitutes a first query response from the third network element device (see page 31 second paragraph)); and
sending, by the first network element device, first indication information to the second network element device when the first query response indicates that the second network element device is in a trusted domain associated with the first network element device, wherein the first indication information indicates to the second network element device to skip performing an authentication operation on the terminal device (see figure 7, S750: the PLMN AMF forwards the registration request to the NPN AMF (see page 31 fourth paragraph); see also figure 6, S650: “The registration request may also carry other indication information, indicating that the terminal has passed [PLMN] authentication and meets the conditions for direct access to the [NPN]” (see page 28 last paragraph to page 29 first paragraph); upon receiving the forwarded request with this indication, the NPN AMF determines to skip authentication, see S760: “the terminal is allowed to not perform NPN authentication”; the list of NPNs/PLMNs that allow direct access constitutes a “trusted domain associated with the first network element device” (see page 31 sixth paragraph).
Toor does not explicitly characterize the query to the UDM and the response from the UDM as a distinct “first query request” and “first query response” exchange in separate, discrete signaling messages. In Toor, the verification at step S740 may be performed via local policy or a query to the UDM, without expressly delineating the request-response pair.
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement Toor’s trust verification (S740) as a discrete query request to, and response from, the UDM (or equivalent third network element), because Toor itself suggests querying the PLMN UDM as one mechanism for trust verification (S740: “query PLMN UDM”), and structuring a query-response exchange as distinct signaling messages is a well-known and routine protocol design technique in 3GPP-based network architectures. A person of ordinary skill in the art would have been motivated to formalize the query as a discrete request/response pair to enable modularity, scalability, and separation of concerns between the AMF and UDM functions. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007) (applying a known technique to a known device/method ready for improvement to yield predictable results supports a conclusion of obviousness).
Consider claim 7, and as applied to claim 6 above, Toor further discloses wherein before receiving, by the first network element device in the public network core network, the first registration request sent by the terminal device, the method further comprises:
receiving, by the first network element device, a second registration request sent by the terminal device, wherein the second registration request requests to access the first network element device (see figure 7, S710: “The terminal completes the authentication and registration process in the PLMN”; inherently, the terminal sends a registration request to the PLMN AMF (first network element device) requesting to access the PLMN, which constitutes a second registration request requesting to access the first network element device (see page 30 seventh paragraph)); and
establishing, by the first network element device, a connection to the terminal device (see figure 7, S710: the terminal “completes the authentication and registration process in the PLMN,” i.e., the PLMN AMF establishes a connection to the terminal device upon successful registration (see page 30 seventh paragraph)).
Consider claim 8, and as applied to claim 7 above, Toor also discloses wherein a format of the first registration request and a format of the second registration request are the same (see figure 6, S620 and Table 1: the registration request for accessing another network through the current network uses the same registration request format as the initial registration request, distinguished only by different values of a “registration type” field; see S620: “The indication information can be realized by setting a value different from the request to access the NPN in the ‘registration type’”; the underlying message format is the same 5G registration request (see page 27 fourth paragraph to page 28 first paragraph)).
Consider claim 9, and as applied to claim 7 above, Toor further discloses performing authentication on the terminal device (see figure 7, S710: “The terminal completes the authentication and registration process in the PLMN. During the registration process, the terminal adopts EAP-AKA’ or 5G AKA authentication method”; the PLMN AMF performs authentication on the terminal device (see page 30 seventh paragraph)).
Consider claim 10, and as applied to claim 6 above, Toor also discloses wherein the first query response comprises second indication information indicating whether the second network element device is in a trusted domain associated with the first network element device (see figure 7, S740: the result of the query to the PLMN UDM indicates whether the NPN that the terminal is trying to access is in the list of networks that allow direct access by the terminal; this yes/no determination constitutes second indication information indicating whether the NPN AMF (second network element device) is in a trusted domain (the allowed-direct-access list) associated with the PLMN AMF (first network element device) (see page 31 second paragraph); see also figure 6, S640: “the NPN queries whether the identity of the PLMN that the terminal is trying to connect to is in the list of PLMN identities that the terminal is allowed to directly access” (see page 28 fourth and fifth paragraph)).
Consider claim 11, and as applied to claim 10 above, Toor further discloses that the query result indicates either that the target network is or is not in the trusted/allowed list (see figure 6 S640/figure7 S740: the verification yields a binary result (the NPN is either in the list or
not) (page 28 fourth and fifth paragraphs and page 31 second paragraph).
Toor does not explicitly disclose that when a value of the second indication information is 1, the second indication information indicates that the second network element device is in a trusted domain, and when a value of the second indication information is 0, the second indication information indicates that the second network element device is not in a trusted domain.
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to encode the binary trust-determination result (in list/not in list) as a single-bit indicator with a value of 1 for “in the trusted domain” and a value of 0 for “not in the trusted domain,” because representing a binary yes/no determination as a 1/0 bit value is a well-known and routine practice in digital communications and protocol design. The selection of specific values (1 = trusted, 0 = not trusted) amounts to an obvious design choice that yields a predictable result—efficient signaling of a two-state determination. See In re Japikse, 181 F.2d 1019, 86 USPQ 70 (CCPA 1950) (design choice); KSR, 550 U.S. at 416 (applying known technique to yield predictable results).
Consider claim 12, and as applied to claim 6 above, Toor also discloses that when the target network is not in the trusted/allowed list, normal authentication procedures apply (see figure 6, S660: “For other terminals, it is necessary to perform the authentication and authorization process of the [NPN/PLMN] in accordance with the normal registration process, without performing subsequent steps (i.e., without skipping authentication)” (see page 29 second full to fifth paragraphs)).
Toor does not explicitly disclose sending, by the first network element device, third indication information to the second network element device when the first query response indicates that the second network element device is not in a trusted domain, wherein the third indication information indicates to the second network element device to perform an authentication operation on the terminal device.
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have the PLMN AMF send an explicit indication to the NPN AMF instructing it to perform authentication when the trust verification fails, because Toor already teaches that the PLMN AMF forwards the registration request to the NPN AMF in all cases (trusted or not), and it is a predictable and routine protocol design choice to explicitly signal the authentication requirement rather than relying on the absence of a “skip” indication. Explicitly signaling “perform authentication” provides clarity, reduces ambiguity in protocol processing, and is the logical converse of sending a “skip authentication” indication. A person of ordinary skill in the art would have been motivated to include such explicit signaling to improve interoperability, avoid protocol misinterpretation, and ensure robust authentication handling across heterogeneous network deployments. See KSR, 550 U.S. at 421 (obvious to try where there are a finite number of identified, predictable solutions with a reasonable expectation of success).
Consider claim 19, Toor discloses Toor discloses a method, comprising:
receiving, by a second network element device in a private network core network, a first registration request from a first network element device in a public network core network, wherein the first registration request comprises an identifier of a terminal device, and the first registration request is a request of the terminal device to access the second network element device (see figure 7, S750: the PLMN AMF (first network element device) forwards the registration request to the NPN AMF (second network element device in the private network core network) (see page 31 fourth paragraph); the registration request includes the terminal’s identifier such as 5G-GUTI (see also figure 8, S850: “NPN AMF also needs to forward the 5G-GUTI generated by NPN to PLMN AMF, so that PLMNAMF can use the 5G-GUTI to identify… the terminal”; the forwarded registration request is a request of the terminal device to access the NPN AMF) (see page 33 second and third paragraphs); and
skipping, by the second network element device, performing an authentication operation on the terminal device when first indication information from the first network element device is received and the first indication information indicates that the second network element device and the first network element device are in a same trusted domain (see figure 7, S760: “After receiving the registration request forwarded by PLMNAMF, the NPNAMF confirms the authentication method that the terminal will use if it registers with the NPN. If the EAP-AKA’ or 5G AKA authentication method is used, the terminal is allowed to not perform NPN authentication” (see page 31 sixth paragraph); the forwarded registration request carries indication information indicating that the terminal has passed PLMN authentication and meets conditions for direct access (see figure 6, S650); the NPN AMF verifies trust [S760] and skips authentication; the mutual trust list membership constitutes being “in a same trusted domain” (see paragraph encompassing pages 28 and 29)).
Toor does not explicitly characterize the indication carried in the forwarded registration request as “first indication information” that expressly states the two network element devices are “in a same trusted domain.” In Toor, the indication conveys that the terminal passed authentication and meets conditions for direct access, and the NPN AMF independently verifies the authentication method.
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the indication information from the PLMN AMF, combined with the NPN AMF’s trust verification, functionally indicates that the two network elements are in a same trusted domain. A person of ordinary skill would have been motivated to explicitly include trust-domain membership status in the indication information to simplify processing at the receiving NPN AMF, reduce redundant verification steps, and improve signaling efficiency. See KSR, 550 U.S. at 416.
Consider claim 20, and as applied to claim 19 above, Toor further discloses wherein before skipping, by the second network element device, performing the authentication operation on the terminal device, the method further comprises:
sending, by the second network element device, a second query request to a third network element device in the private network core network, wherein the second query request comprises an identifier of the first network element device, and the second query request queries whether the first network element device is in a trusted domain associated with the second network element device (see figure 7, S760: the NPN AMF confirms the authentication method and verifies trust (see page 31 sixth paragraph); figure 6, S660: “PLMN can maintain an NPN ‘white list’ list, and only requests from NPNs in this list can skip PLMN authentication”, by analogy, the NPN maintains a similar list of trusted PLMNs and verifies whether the PLMN AMF is trusted; the verification may involve querying the NPN UDM (third network element device in the private network core network) for the trusted list (see page 29 third full paragraph)); and
receiving, by the second network element device, a second query response from the third network element device (figure 7, S760: the NPN AMF receives the verification result, i.e., whether the PLMN is trusted, from the query to the NPN UDM or local policy (see page 31 sixth paragraph)); and
wherein skipping, by the second network element device, performing the authentication
operation on the terminal device when the first indication information from the first network element device is received, the first indication information indicates that the second network element device and the first network element device are in the same trusted domain, and the second query response indicates that the first network element device is in the trusted domain associated with the second network element device (see figure 7, S760: the NPN AMF skips authentication only when both conditions are met: (1) the forwarded registration request carries indication that the terminal meets conditions for direct access (first indication information), and (2) the NPN AMF’s own verification confirms that the PLMN’s authentication method is acceptable (second query response indicates the PLMN AMF is trusted) (page 31 sixth paragraph); see also figure 6, S660: the receiving AMF checks both the indication and its own whitelist/policy before allowing the terminal to skip authentication (page 29 second and third full paragraphs)).
To the extent that Toor does not explicitly characterize the NPN AMF’s trust verification as a discrete “second query request” to a separate “third network element device in the private network core network,” it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the NPN AMF’s verification as a query to the NPN UDM (a third network element in the private network core network), because Toor teaches the analogous mechanism on the PLMN side (S740: “query PLMN UDM”), and implementing the same query mechanism on the NPN side is a straightforward, predictable application of the same architectural pattern to achieve the same verification function. See KSR, 550 U.S. at 417 (applying same known technique in same way to substantially similar problem).
Consider claim 21, and as applied to claim 19 above, Toor also discloses wherein the first indication information comprises the identifier of the terminal device (see figure 7, S750/figure 6, S650: the PLMN AMF forwards the registration request to the NPN AMF, and the registration request includes the terminal’s identifier such as 5G-GUTI; the indication information is carried within or alongside the registration request that includes the terminal identifier (see the paragraph encompassing pages 28 and 29, page 31 fourth and five paragraphs); see also figure 8, S850: “NPN AMF also needs to forward the 5G-GUTI… so that PLMNAMF can use the 5G-GUTI to identify… the terminal”; thus, the indication information sent from the PLMN AMF to the NPN AMF comprises the identifier of the terminal device (see page 33 first and second full paragraph)).
Consider claim 22, and as applied to claim 19 above, Toor further discloses that the indication information and the terminal identifier may be conveyed in the same forwarded registration request (see analysis of Claim 21 above).
Toor does not explicitly disclose that the first indication information does not comprise the identifier of the terminal device.
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to separate the indication information from the terminal identifier such that the first indication information does not comprise the identifier of the terminal device, because the trust indication (skip/perform authentication) and the terminal identity are logically distinct data elements serving different functions. A person of ordinary skill in the art would have been motivated to decouple them for protocol flexibility, enabling the indication to be sent in a separate signaling message or field independent of the terminal identifier, which is a routine and predictable design choice in 3GPP signaling protocol design. See In re Japikse, 181 F.2d 1019, 86 USPQ 70 (CCPA 1950) (rearrangement of information is a design choice); KSR, 550 U.S. at 416.
Consider claim 23, Toor discloses a device (communication device 1100 - figure 11), comprising:
at least one processor (figure 11: processor 1110; see also page 37 sixth paragraph: “the communication device 1100 may include a processor 1110, a memory 1120, and a transceiver 1130”); and
memory storing instructions that are executable by the at least one processor (see figure 11: memory 1120; see page 37 fifth paragraph: “The storage unit is used to store instructions, and the processing unit executes the instructions stored in the storage unit, so that the communication device executes the foregoing method”), wherein execution of the instructions causes the device to:
receive, in a public network core network, a first registration request sent by a terminal device, wherein the first registration request is a request of the terminal device to access a second network element device in a private network core network (same analysis as in claim 6, first limitation; see figure 7, S720–S730 and page 30 last paragraph to page 31 first paragraph);
send a first query request to a third network element device in the public network core network (same analysis as claim 6, second limitation; see figure 7, S740: query to PLMN UDM - page 31 second and third paragraphs);
receive a first query response from the third network element device (same analysis as claim 6, third limitation; see figure 7, S740: result from PLMN UDM - page 31 second and third paragraphs); and
send first indication information to the second network element device when the first query response indicates that the second network element device is in a trusted domain associated with the device, wherein the first indication information indicates to the second network element device to skip performing an authentication operation on the terminal device (same analysis as claim 6, fourth limitation; see figure 7, S750 via figure 6, S650, see page 28 last paragraph to page 29 first paragraph, and page 31 sixth paragraph)).
The same obviousness rationale set forth in the rejection of claim 6 applies to claim 23. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement Toor’s trust verification as a discrete query request/response exchange with a third network element (UDM), for the same reasons articulated in the rejection of claim 6. See KSR, 550 U.S. at 416.
Consider claim 24, and as applied to claim 23 above, Toor also discloses execution of the instructions causes the device further to:
before receiving, in the public network core network, the first registration request sent by the terminal device, receive a second registration request sent by the terminal device, wherein the second registration request requests to access the device (see figure 7, S710: “The terminal completes the authentication and registration process in the PLMN”; inherently, the terminal sends a registration request to the PLMN AMF requesting to access the PLMN, which constitutes a second registration request requesting to access the device (see page 30 seventh paragraph)); and
establishing a connection to the terminal device (see figure 7, S710: the terminal “completes the authentication and registration process in the PLMN,” i.e., the PLMN AMF establishes a connection to the terminal device upon successful registration (see page 30 seventh paragraph)).
Consider claim 25, and as applied to claim 247 above, Toor further discloses wherein a format of the first registration request and a format of the second registration request are the same (see figure 6, S620 and Table 1: the registration request for accessing another network through the current network uses the same registration request format as the initial registration request, distinguished only by different values of a “registration type” field; see S620: “The indication information can be realized by setting a value different from the request to access the NPN in the ‘registration type’”; the underlying message format is the same 5G registration request (see page 27 fourth paragraph to page 28 first paragraph)).
Consider claim 26, and as applied to claim 24 above, Toor also discloses wherein execution of the instructions causes the device further to:
perform authentication on the terminal device (see figure 7, S710: “The terminal completes the authentication and registration process in the PLMN. During the registration process, the terminal adopts EAP-AKA’ or 5G AKA authentication method”; the PLMN AMF performs authentication on the terminal device (see page 30 seventh paragraph)).
Consider claim 27, and as applied to claim 23 above, Toor further discloses wherein the first query response comprises second indication information indicating whether the second network element device is in a trusted domain associated with the device (see figure 7, S740: the result of the query to the PLMN UDM indicates whether the NPN that the terminal is trying to access is in the list of networks that allow direct access by the terminal; this yes/no determination constitutes second indication information indicating whether the NPN AMF (second network element device) is in a trusted domain (the allowed-direct-access list) associated with the PLMN AMF (device) (see page 31 second paragraph); see also figure 6, S640: “the NPN queries whether the identity of the PLMN that the terminal is trying to connect to is in the list of PLMN identities that the terminal is allowed to directly access” (see page 28 fourth and fifth paragraph)).
Consider claim 28, and as applied to claim 27 above, Toor also discloses that the query result indicates either that the target network is or is not in the trusted/allowed list (see figure 6 S640/figure7 S740: the verification yields a binary result (the NPN is either in the list or
not) (page 28 fourth and fifth paragraphs and page 31 second paragraph).
Toor does not explicitly disclose that when a value of the second indication information is 1, the second indication information indicates that the second network element device is in a trusted domain, and when a value of the second indication information is 0, the second indication information indicates that the second network element device is not in a trusted domain.
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to encode the binary trust-determination result (in list/not in list) as a single-bit indicator with a value of 1 for “in the trusted domain” and a value of 0 for “not in the trusted domain,” because representing a binary yes/no determination as a 1/0 bit value is a well-known and routine practice in digital communications and protocol design. The selection of specific values (1 = trusted, 0 = not trusted) amounts to an obvious design choice that yields a predictable result—efficient signaling of a two-state determination. See In re Japikse, 181 F.2d 1019, 86 USPQ 70 (CCPA 1950) (design choice); KSR, 550 U.S. at 416 (applying known technique to yield predictable results).
Consider claim 29, and as applied to claim 23 above, Toor further discloses wherein execution of the instructions causes the device further to:
when the target network is not in the trusted/allowed list, normal authentication procedures apply (see figure 6, S660: “For other terminals, it is necessary to perform the authentication and authorization process of the [NPN/PLMN] in accordance with the normal registration process, without performing subsequent steps (i.e., without skipping authentication)”
(see page 29 second full to fifth paragraphs)).
Toor does not explicitly disclose sending third indication information to the second network element device when the first query response indicates that the second network element device is not in a trusted domain, wherein the third indication information indicates to the second network element device to perform an authentication operation on the terminal device.
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have the PLMN AMF send an explicit indication to the NPN AMF instructing it to perform authentication when the trust verification fails, because Toor already teaches that the PLMN AMF forwards the registration request to the NPN AMF in all cases (trusted or not), and it is a predictable and routine protocol design choice to explicitly signal the authentication requirement rather than relying on the absence of a “skip” indication. Explicitly signaling “perform authentication” provides clarity, reduces ambiguity in protocol processing, and is the logical converse of sending a “skip authentication” indication. A person of ordinary skill in the art would have been motivated to include such explicit signaling to improve interoperability, avoid protocol misinterpretation, and ensure robust authentication handling across heterogeneous network deployments. See KSR, 550 U.S. at 421 (obvious to try where there are a finite number of identified, predictable solutions with a reasonable expectation of success).
Claims 13 and 30 are rejected under 35 U.S.C. § 103 as being unpatentable over Toor et al. (WO 2020/215272 A1, hereinafter “Toor”) in view of Lu et al. (CN 111132149 A, hereinafter “Lu”).
Citations refer to below are from the attached machine translation document of Lu et al.
Consider claims 13 and 30, and as applied to claims 6 and 23 above, Toor also teaches a trusted domain concept in which the first network element device (PLMN AMF) determines whether the second network element device (NPN AMF) is in a trusted domain associated with the first network element device, based on a list of trusted networks maintained in the PLMN (see figure 6, S640: “the NPN queries whether the identity of the PLMN that the terminal is trying to connect to is in the list of PLMN identities that the terminal is allowed to directly access” (see page 28 fifth paragraph; figure 7, S740: “the PLMNAMF verifies whether the NPN that the terminal is trying to connect to is an NPN that allows the terminal to directly access according to the local policy or query PLMN UDM” (see page 31 second paragraph); “Generally, the PLMN that allows the terminal to directly access has a pre-arranged agreement with the NPN. For example, NPN itself is hosted by PLMN or implemented as a network slice of PLMN” (see page 28 sixth paragraph); and “PLMN can maintain an NPN ‘white list’ list, and only requests from NPNs in this list can skip PLMN authentication” (see page 29 third full paragraph)).
Toor further teaches that the trust relationship may be based on various criteria, including: the first and second networks using the same authentication method, one network being a slice of the other, one network being a CAG group of the other, or both networks being operated by the same operator (Toor, Description: “For example, the authentication methods of the two networks are the same, or the second network is a slice of the first network… or the first network when the first network and the second network are operated by the same operator, etc.” (see page 10 third paragraph); and “The trusted network of the second network may have one or more of the following characteristics: the authentication method of the second network is the same, or, it is a slice of the second network, or the second network is its slice, or, it is the CAG
group of the second network… or a mutual trust agreement with the second network” (see page
16 first paragraph).
Toor does not explicitly disclose that the trusted domain is a consortium blockchain of a public land mobile network stored in a blockchain system.
Lu teaches, in an analogous field of 5G mobile communication security, a consortium blockchain of a public land mobile network stored in a blockchain system (Lu, pages 7 and 8 on the description accompanying step 101: “blockchain referred to in this embodiment is a block chain maintained by several operators, temporary identity registration server of each operator access the block chain and recording and maintaining all the latest public key of the operator in the block chain”; see also the description of figure 2 on page 8: “the operator can be understood as referred to in this embodiment 5G core network (5GC) sends the public key of the operator in the block chain for accounting. operator of the temporary identity registration server access to the block chain, and to record and maintain the public key of each operator”; the blockchain maintained by several operators constitutes a consortium blockchain of PLMNs stored in a blockchain system; Lu further teaches that the blockchain serves as a trust anchor: “5G UE or other terminal devices can be used as node of blockchain accesses to the blockchain, at the same time, the blockchain can be used for recording blockchain on each node of the registration information and the transaction information of each node to each other” (see the paragraph encompassing pages 8 and 9)).
Lu further teaches that using a blockchain maintained by multiple operators for storing trust-related information (e.g., operator public keys) provides improved security by preventing tampering or replacement of trust-critical data in the communication system (see the abstract: “so as to prevent the third public key is modified or replaced. improves the data safety and security of 5G UE in the registration process”; see the background: “in the SIM card-free access scheme when no 5G UE SIM card submits the public key of its own, malicious intermediary or monitoring is easy to replace the public key. and the operator cannot sense, this may be monitored all secure communication between the UE and the operator of the 5G”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the trusted domain of Toor, i.e., the whitelist or policy-based trust relationship maintained between PLMN and NPN network elements, such that the trusted domain is implemented as a consortium blockchain of a public land mobile network stored in a blockchain system, as taught by Lu.
A person of ordinary skill in the art would have been motivated to make this modification for at least the following reasons:
First, both Toor and Lu are directed to security mechanisms in 5G mobile communication networks, and both address the fundamental problem of establishing and verifying trust relationships between network entities. Toor addresses trust between public and private core network elements for authentication purposes, and Lu addresses trust in operator public keys used during UE registration. Both references operate in the same field of endeavor and address analogous trust verification problems.
Second, Lu teaches that a consortium blockchain maintained by multiple operators provides inherent tamper-resistance and data integrity for trust-critical information (see the abstract: “so as to prevent the third public key is modified or replaced”). A person of ordinary skill in the art would have recognized that implementing Toor’s trust domain as a consortium blockchain would provide the same tamper-resistance and data integrity advantages for the trusted network list, thereby enhancing the security and reliability of Toor’s cross-network trust
verification mechanism.
Third, implementing the trusted domain as a consortium blockchain aligns with the well-recognized trend toward decentralized trust management in telecommunications. A person of ordinary skill in the art would have recognized that a consortium blockchain provides multi-party consensus among participating operators, eliminating reliance on a single centralized trust authority and providing a more robust and resilient trust verification mechanism. This modification represents the application of a known technique (consortium blockchain for trust management, as taught by Lu) to a known system (Toor’s inter-network authentication framework) to yield the predictable result of a tamper-resistant, decentralized trust domain. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007).
The combination does not change the fundamental operation of Toor’s method. The PLMN AMF would still query a third network element (e.g., a blockchain function or BCF) to determine whether the NPN AMF is in the trusted domain, receive a response, and send indication information to the NPN AMF to skip authentication. The only difference is that the trusted domain information would be derived from a consortium blockchain maintained by operators rather than a locally stored whitelist or UDM policy. This substitution of the trust information source is a straightforward and predictable modification that does not alter the overall signaling flow or the authentication skip mechanism.
Conclusion
The prior art made of record and not relied upon is considered pertinent to Applicant’s disclosure.
Zhang et al. (CN 108683690 A) disclose an authentication method, user equipment,
authentication device, authentication server, and storage medium.
Li (CN 111866858 A) discloses a registration method and communication device.
Lei (U.S. Patent # 12,483,472 B2) discloses a slice authentication method and apparatus.
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Rafael Pérez-Gutiérrez
R.P.G./rpg
/Rafael Pérez-Gutiérrez/
Supervisory Patent Examiner, Art Unit 2642
October 1, 2026
