DETAILED ACTION
Response to Amendment
This is in response to Applicants amendment filed 12/11/2025 which has been entered. Claims 1, 11 and 22 have been amended. No Claims have been cancelled. No Claims have been added. Claims 1-30 are still pending in this application, with Claims 1, 11 and 22 being independent.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-30 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1, 8-11, 18-22, 29 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Deivasigamani et al (2016/0353344 A1) in view of Gong et al (2023/0319189 A1), and further in view of Holmberg – Indication of Support for Keep-Alive, hereinafter referred to as Holmberg.
As per Claim 1, Deivasigamani teaches a method of wireless communication performed by a user equipment (UE), comprising: attempting a mobile originated packet switched call across a packet switched network (Page 4, Paragraph [0038]; Page 5, Paragraphs [0045] and [0046]) with a first transmission control protocol (TCP) connection of an Internet Protocol multimedia subsystem (IMS) session (Page 4, Paragraph [0039]); performing a silent redial of the mobile originated packet switched call via a circuit switched network, in response to a failure of the mobile originated packet switched call (Page 5, Paragraph [0047]).
Deivasigamani does not teach reconnecting to the packet switched network without re-establishing the first TCP connection after terminating the circuit switched network call. However, Gong teaches reconnecting to the packet switched network without re-establishing the first TCP connection after terminating the circuit switched network call (Table 1: Page 18, Paragraphs [0287] – Page 19, Paragraph [0305]).
(Note: In paragraph [0288], Gong indicates that when a preset trigger condition is met, the calling terminal determines whether a silent redial trigger condition is met and if so, an automatic silent redial is initiated. In paragraph [0288], Gong indicates the preset condition includes a timeout trigger and/or a network disconnection trigger. In paragraph [0294], Gong indicates the network disconnection trigger includes a network error code scenario and a network exception scenario)
(Note: In paragraphs [0294] – [0296], Gong describes determining a silent redial condition in response to receiving a network error code or when a network exception occurs. Table 1 illustrates network error codes that occur in a packet switched network and/or in a circuit switched network. In paragraphs [0302] – [0305], Gong describes a process of reconnecting to the packet switched network without re-establishing the first TCP connection after terminating the circuit switched network call)
It would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the method taught by Deivasigamani with the method taught by Gong to employ keep-alive messages as a health check in session oriented protocols like the session initiated protocol [SIP], allowing the network to supervise the session and ensure both ends are still reachable and active.
The combination of Deivasigamani and Gong does not teach transmitting a keep alive message over the packet switched network in accordance with reconnecting to the packet switched network. However, Holmberg teaches transmitting a keep alive message over the packet switched network in accordance with reconnecting to the packet switched network.
(Note: The user equipment [UE] shown in Deivasigamani uses session initiation protocol [SIP] and IMS to register at the proxy-call service control function [P-CSCF] according to the SIP standard [See Page 10 of Holmberg] a SIP registration at a proxy uses keep-alive messages. Figure 4 shows that the change in radio access technology [RAT] is performed after communication via a RAT [See Paragraph 0053 -voice traffic]. As such the use of keep-alive messaging is implicitly disclosed in Deivasigamani)
(Note: With respect to reconnecting to the packet switched network, In paragraph [0053], Deivasigamani describes the UE reconnecting to a RAT [e.g. LTE-RAN, legacy RAN, etc.]. In paragraph [0053], Deivasigamani indicates that the UE may switch RATs; and further indicates that if a RAT change is detected, the UE will automatically re-initiate a connection [e.g. a TCP connection] with the P-CSCF and a switch from a legacy RAT to LTE is performed)
It would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the method taught by Deivasigamani and Gong with the method taught by Holmberg to more easily detect and recover from broken connections, prevent network components from timing out idle connections, and facilitate faster, more efficient reconnection once service is restored.
As per Claims 8, 18 and 29, the combination of Deivasigamani, Gong and Holmberg teaches wherein the keep alive message syncs a TCP connection status between the UE and a first proxy call session control function (P-CSCF). (Note: The use of a keep-alive message via TCP implicitly syncs a TCP connection status, as the keep-alive message is sent via said TCP connection)
It would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the method and system taught by Deivasigamani and Gongwith the method and system taught by Holmberg to more easily detect and recover from broken connections, prevent network components from timing out idle connections, and facilitate faster, more efficient reconnection once service is restored.
As per Claims 9, 10, 19, 20 and 30, the combination of Deivasigamani, Gong and Holmberg teaches wherein the packet switched network is a new radio (NR) network; and wherein the packet switched network is a long-term evolution network (LTE) (Deivasigamaini: Page 2, Paragraphs [0017] and [0018]). (Note: The claims define common implementation options which are found to be obvious when considered in context with the teachings of Deivasigamaini)
It would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the method and system taught by Deivasigamani and Gong with the method and system taught by Holmberg to more easily detect and recover from broken connections, prevent network components from timing out idle connections, and facilitate faster, more efficient reconnection once service is restored.
As per Claims 11 and 22, the combination of Deivasigamani, Gong and Holmberg teach a method as described in Claim 1. Deivasigamani also teaches comprising: a memory (Figure 7 – Reference 760; Page 7, Paragraphs [0066] and [0067]); at least one processor coupled to the at least one memory (Figure 7 – Reference 710 and 730; Page 7, Paragraphs [0066] and [0067]); and instructions stored in the memory (Page 7, Paragraphs [0069]).
It would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the method and system taught by Deivasigamani and Gong with the method and system taught by Holmberg to more easily detect and recover from broken connections, prevent network components from timing out idle connections, and facilitate faster, more efficient reconnection once service is restored.
Claim(s) 2, 3, 12, 13, 23 and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Deivasigamani et al (2016/0353344 A1) in view of Gong et al (2023/0319189 A1), and further in view of Holmberg – Indication of Support for Keep-Alive, hereinafter referred to as Holmberg as applied to Claims 1, 11 and 22 above, and further in view of Yamazaki et al (2010/0161745 A1).
As per Claims 2, 3, 12, 13, 23 and 24, the combination of Deivasigamani and Holmberg teaches the method of Claim 1; but does not teach transmitting a first TCP message to a first proxy call session control function (P-CSCF) to attempt to re-establish the first TCP connection with the first P-CSCF, in response to a first timer expiring before receiving a response to the keep alive message; and transmitting a second TCP message to a second P-CSCF in response to a second timer expiring before receiving a response to the first TCP message, the second TCP message attempting to re-establish the first TCP connection with the second P-CSCF and attempting to register with the second P-CSCF.
However, Yamazaki teaches transmitting a first TCP message to a first proxy call session control function (P-CSCF) to attempt to re-establish the first TCP connection with the first P-CSCF, in response to a first timer expiring before receiving a response to the keep alive message; and transmitting a second TCP message to a second P-CSCF in response to a second timer expiring before receiving a response to the first TCP message, the second TCP message attempting to re-establish the first TCP connection with the second P-CSCF and attempting to register with the second P-CSCF (Page 5, Paragraphs [0046] and [0047]). (Note: It is a common practice in a survivable system to not immediately switch to a backup system in the event that a timeout condition occurs; but rather retry the primary system)
It would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the method and system taught by Deivasigamani and Holmberg with the method and system taught by Yamazaki to recover from failed connection attempts as retries are significantly faster and more cost-effective for resolving minor, temporary network issues. Switching to a backup system is a more complex and resource-intensive process reserved for significant outages.
Allowable Subject Matter
Claims 4-7, 14-17 and 25-27 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Gaur et al (2017/0181215 A1), Kalepu et al (2018/0132291 A1), Nomani et al (2017/0353505 A1), Shukair et al (2015/0201454 A1) and Kim et al (10,327,277 B2).
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KHARYE POPE whose telephone number is (571)270-5587. The examiner can normally be reached Monday - Friday 8AM - 4PM.
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KHARYE POPE
Primary Examiner
Art Unit 2693
/KHARYE POPE/Primary Examiner, Art Unit 2693