UNITED STATES PATENT AND TRADEMARK OFFICE INVENTORS: JIONGJIONG GU, FENG LIANG, LINFEI SHEN, SHUFENG SHI, KAI WEN

Transcription

1 Docket No.: UNITED STATES PATENT AND TRADEMARK OFFICE PATENT: 8,719,617 INVENTORS: JIONGJIONG GU, FENG LIANG, LINFEI SHEN, SHUFENG SHI, KAI WEN FILED: October 31, 2011 ISSUED: May 6, 2014 TITLE: METHOD AND DEVICE FOR REALIZING IP MULTIMEDIA SUBSYSTEM DISASTER TOLERANCE BEFORE THE PATENT TRIAL AND APPEAL BOARD T-Mobile US, Inc. and T-Mobile USA, Inc. Petitioners v. Huawei Technologies Co. Ltd. Patent Owner Case IPR PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 8,719,617 UNDER 35 U.S.C. 312 AND 37 C.F.R

2 TABLE OF CONTENTS i U.S. Patent 8,719,617 I. INTRODUCTION... 1 II. MANDATORY NOTICES... 1 A. Real Parties-in-Interest... 1 B. Related Matters... 1 C. Counsel... 1 D. Service Information... 2 III. CERTIFICATION OF GROUNDS FOR STANDING... 2 IV. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED... 2 A. Prior Art Patents and Printed Publications... 2 B. Level of Ordinary Skill in the Art... 3 C. Relief Requested... 4 V. OVERVIEW OF THE 617 PATENT... 4 A. Background IMS Technology IMS Core Components IMS Information Flows... 7 B. Purported Problem and Solution of the 617 Patent C. Summary of the Prosecution History VI. CLAIM CONSTRUCTION A. restoration data / restoring data VII. GROUNDS FOR CHALLENGE A. Overview of Prior Art B. Ground 1: Claims 1, 5, and 7 Are Invalid As Obvious Over the Combination of Phan-Anh and S Overview of Phan-Anh Overview of S The 3GPP Documents Qualify As Prior Art to the 617 Patent Claim

3 5. Claim Claim Reasons to Combine Phan-Anh and S C. Ground 2: Claims 1, 4, 5, 7, and 10 Are Invalid As Obvious Over Phan-Anh Combination With S and TS Claims 1, 5, and Claims 4 and D. Ground 3: Claims 1, 4, 5, 7, and 10 Are Invalid As Obvious Over Phan-Anh In View of TR , S and TS VIII. CONCLUSION ii

4 I. INTRODUCTION U.S. Patent 8,719,617 U.S. Patent No. 8,719,617 ( the 617 patent, Ex. 1001) claims as inventive the straightforward application of well-known, decades-old, checkpointing recovery techniques to the context of an IMS network. Not only was the core idea old, but others, including Ericsson and Nokia, already had publicly proposed the very same techniques for IMS networks before the priority date of the 617 patent. II. MANDATORY NOTICES A. Real Parties-in-Interest T-Mobile US, Inc. and T-Mobile USA, Inc. ( Petitioners ) and Nokia Solutions and Networks US LLC and Nokia Solutions and Networks OY are the real parties-in-interest and submit this inter partes review Petition ( Petition ) for review of certain claims of U.S. Patent No. 8,719,617 ( 617 patent ). B. Related Matters The following litigation matter would affect or be affected by a decision in this proceeding: Huawei Technologies Co. Ltd. v. T-Mobile US, Inc. et al., Case No. 2:16-cv JRG-RSP (E.D. Tex. Jan. 15, 2016). Petitioners have or soon will file inter partes review petitions for U.S. Patent Nos. 8,625,527; 8,531,971; 8,069,365; and 8,638,750, which are also asserted in cases between the same parties in litigation before the same court. C. Counsel Lead Counsel: Peter M. Dichiara (Registration No. 38,005) 1

5 Backup Counsel: Joseph F. Haag (Registration No. 42,612) Backup Counsel: Evelyn C. Mak (Registration No. 50,492) U.S. Patent 8,719,617 Backup Counsel: Kathryn D. Zalewski (pro hac vice to be requested) D. Service Information Post and Hand Delivery: WilmerHale, 60 State St., Boston MA Telephone: Petitioners consent to service by . III. CERTIFICATION OF GROUNDS FOR STANDING Petitioners certify pursuant to Rule (a) that the 617 patent is available for inter partes review and that Petitioner is not barred or estopped from requesting an inter partes review challenging the patent claims on the grounds identified in this Petition. IV. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED Pursuant to Rules 42.22(a)(1) and (b)(1)-(2), Petitioners challenge claims 1, 4, 5, 7, and 10 of the 617 Patent (the challenged claims ) and request that each challenged claim be canceled. A. Prior Art Patents and Printed Publications Petitioners rely upon the patents and printed publications listed in the Table of Exhibits, including: 2

6 1. U.S. Patent No. 7,769,374 to Phan-Anh et al., filed March 12, 2001 ( Phan-Anh, Ex. 1003). 2. 3GPP Technical Report v1.0.1 (July 2000), 3rd Generation Partnership Project, Architecture Principles for Release 2000 ( TR , Ex. 1004). 3. S , Reassignment for S-CSCF during the terminated call procedure, Huawei, 3GPP TSG SA WG2 #50, January 16-20, 2006 ( S , Ex. 1005). 4. 3GPP Technical Specification v7.2.0 (December 2005), IP Multimedia Subsystem (IMS); Stage 2 ( TS , Ex. 1007). B. Level of Ordinary Skill in the Art The 365 patent relates to the field of communications technology in general, and more specifically the operation of components of the IP Multimedia Subsystem (IMS). At the time the 365 patent was filed, a person of ordinary skill in this field would have had at least a bachelor s degree in computer science or electrical engineering and 3-4 years of professional experience in communications technology, or equivalent academic experience. Such a person would have been familiar with the 3GPP standard in general and preferably to its specifications related to IMS. (Ex. 1002, Decl. 21.) 3

7 C. Relief Requested U.S. Patent 8,719,617 Petitioners request that the Patent Trial and Appeal Board cancel the challenged claims because they are unpatentable under 35 U.S.C. 103 as set forth in this Petition. This conclusion is supported by the declaration of Mr. Craig Bishop ( Bishop Declaration, Ex. 1002), filed herewith. V. OVERVIEW OF THE 617 PATENT The 617 patent describes methods and components for recovering a user service in an IP multimedia subsystem (IMS) when a particular server in that system (called the Serving Call Session Control Function, or S-CSCF) fails. 1 (Ex. 1002, Decl. 44.) A. Background IMS Technology IMS is a well-known system first standardized by the 3 rd Generation Partnership Project ( 3GPP ) from 2001through 2002, long before the priority date of the 617 patent. IMS was developed as a solution for IP-based multimedia communications following an initial 3GPP study of an Architecture for All IP Network, which itself started in (See Ex. 1008, SP (June 2000 Work 1 The 617 issued from a continuation application that ultimately issued as U.S. Patent No. 8,069,365. Petitioner also has filed a petition for inter partes review of the 365 patent, based on the same prior art. Accordingly, the discussion of the 617 patent and prior art that follows is similar to that in the 365 petition. 4

8 Item description for IMS).) U.S. Patent 8,719,617 IMS was designed to enable network operators to offer their subscribers multimedia services based on and built upon Internet applications, services, and protocols. (See id.) The IMS Core Network contains Session Initiation Protocol (SIP) servers, called control functions, as well as a user database. IMS uses SIP as the signaling mechanism between the control functions for establishing, modifying, and ending sessions. (Ex at 26 (signaling flows based on SIP).) SIP was first standardized in 1999 and has been commonly used over Internet Protocol networks since then. (See Ex at 14.) The diagram below shows the IMS core network components relevant to this Petition: 5

9 (Ex. 1009, CSCF in VoLTE, located at U.S. Patent 8,719, /cscf-in-volte-the-p-cscf-part-1-of-4.aspx.) (Ex. 1002, Decl ) 1. IMS Core Components IMS and its components were defined by the standards promulgated by 3GPP before the 617 patent, and described in Technical Specification (Ex. 1002, Decl. 50.) In relevant part, an IMS core network includes three types of Call Session Control Function (CSCF) and a Home Subscriber Server (HSS), each of which was well known in the prior art before the patent: P-CSCF: The proxy CSCF ( P-CSCF ) is the first point of contact within the IMS for a mobile terminal ( UE ) requesting registration with the IMS or requesting a service. The UE attaches to a P-CSCF before it can register with IMS or communicate within IMS. For example, the P-CSCF will forward requests from the UE to register with IMS. It will also forward and receive requests for calls for the UE. The UE remains attached to the same P-CSCF for the duration of its registration. (See Ex. 1001, 1:39-45, Figs. 1, 2.) I-CSCF: The interrogating CSCF ( I-CSCF ) is the first point of contact within the IMS for the P-CSCF of a UE that is requesting registration or is already registered. The I-CSCF will receive 6

10 registration requests from the UE sent via a P-CSCF, and will assign a Serving CSCF (S-CSCF) to the user during registration. It also will receive all messages destined for users of that network, and will determine where to forward those messages. (See id.) S-CSCF: The serving CSCF ( S-CSCF ) is the heart of the IMS core network. In addition to its SIP Server functionality, the S-CSCF acts as a SIP registrar by registering the user, and instructing the HSS to record the assigned S-CSCF information with the user s profile. (See id., 2:6-21, 2:36-40.) The S-CSCF provides session control services for the UEs registered with it. Different S-CSCFs within an operator s network may have different capabilities. (See id., 1:46-62.) HSS: The Home Subscriber Server is a master user database that was first introduced during the 1999 study on the All-IP network. It contains the subscription-related information (subscriber profiles). (See id., 1:46-47, 2:35-36.) (Ex. 1002, Decl. 50.) 2. IMS Information Flows TS , the prior art standard which defines IMS, uses the term information flow to refer to the interactions between components and illustrates the flows with diagrams. (Ex at 44.) The 617 patent admits that the 7

11 relevant information flows for IMS were known in the prior art. (Ex. 1001, 1:25-3:8.) As will be seen below, the purported invention uses these same flows and the messages that implement them. (Ex. 1002, Decl ) For example, Figure 1 of the patent depicts an information flow for a user who subscribes and registers in the IMS network in the prior art, and Figure 2 shows setting up a session between a calling party and a called party registered in the IMS in the prior art. (Ex. 1001, 1:36-38, 2:44-46.) As Mr. Bishop confirms, Figures 1 and 2 and the accompanying descriptions are identical in substance to those shown in prior art TS and version of TS ( TS , Ex. 1010), both published in December (Ex at 44, 80-83; Ex at 36, 39, 40.) Although the flows have many steps, at most only three or four steps are relevant to the 617 claims. (Ex. 1002, Decl. 55.) Registration: In the first prior art information flow, the UE requests registration and the I-CSCF assigns an S-CSCF to the UE. This flow, as specified in TS and TS , is shown in Figure 1 of the 617 patent (highlighted in color below): 8

12 (Ex. 1001, Fig. 1, 1:36-38; Ex at 44, Fig. 5.1; Ex at Fig. A ) The UE (the user equipment or mobile device) sends a register request message to the P-CSCF, which forwards it to an I-CSCF (2. REGISTER). (Ex. 1001, 1:39-45; see also Ex at 44, Fig. 5.1.) (Ex. 1002, Decl. 56.) The I-CSCF then assigns an S-CSCF to the user (yellow). To do so, the I- CSCF interrogates the HSS by sending a User-Authorization-Request ( UAR ) message to the HSS requesting information about the service processing capabilities the S-CSCF must have to service the particular user requesting 9

13 registration. (Ex. 1001, 1:46-53; Ex at ) The HSS returns a User- Authorization-Answer ( UAA ) message identifying the service processing capabilities required by the user. (Ex. 1001, 1:53-58.) The I-CSCF then assigns an S-CSCF to the user according to the capability set requirements, and forwards the register request to the assigned S-CSCF (blue). (Id., 1:58-62, 2:12-15; Ex at 45 ( the I-CSCF shall perform the new S-CSCF selection function based on the capabilities returned ).) (Ex. 1002, Decl. 57.) Thereafter, the S-CSCF records the assignment information in the HSS (green). The S-CSCF sends a Server-Assignment-Request ( SAR ) interface message to the HSS containing the name of the assigned S-CSCF and the identity of the registered user. (Ex. 1001, 2:19-21.) The HSS stores the S-CSCF information with the user information, and returns a Server-Assignment-Answer ( SAR ) message containing subscriber information (including user profile) to the S-CSCF. (Id., 2:19-21, 2:35-36; Ex at ) The S-CSCF locally stores the subscription service data of the user,... the address of the P-CSCF where the user passes through when getting access to the IMS network, and a contact address of the user terminal. (Id., 2:36-40; see also Ex at 45, 47 ( The S-CSCF shall store the P-CSCF address/name and information for the indicated user ).) A registration timer is then started, which will force periodic re-registration upon expiration to ensure that the user is still reachable. (Ex. 1001, 3:42-44.) (Ex. 1002, 10

14 Decl. 58.) U.S. Patent 8,719,617 Mobile Origination/Termination: After registration, the UE can make calls ( mobile origination ) and receive calls ( mobile termination ). The general flow for setting up a session is shown in Figure 2: (Ex. 1001, Fig. 2, 2:44-46.) The calling UE sends a session setup request (i.e., INVITE) to its P-CSCF, which then routes... the request to the S-CSCF with which the calling party registers (steps 1 and 2). (Id., 2:51-53.) The S-CSCF of the calling UE then routes the request message to the I-CSCF in the called party s home network (step 3). (Id., 2:53-56.) The I-CSCF determines the address of the S-CSCF with which the called user registers by sending a Location Info Request ( LIR ) message to the HSS, which returns a Location Info Answer ( LIA ) message containing the address (steps 4 and 5). (Id., 2:56-58; Ex at 11

15 20-21 (describing the LIR and LIA messages).) The I-CSCF forwards the session setup request to the called UE via the S-CSCF and the P-CSCF where the called user passes through when getting access to the IMS network. (Ex. 1001, 2:59-3:3; Ex. 1002, Decl. 59.) All the messages discussed above were specified in TS prior to the invention of the 617 patent. (Ex at 10-17, 20, 21.) (Ex. 1002, Decl. 60.) B. Purported Problem and Solution of the 617 Patent The 617 patent explains that, in the prior art, if the S-CSCF fails, assignment of a new S-CSCF will not occur until re-registration is triggered via expiration of the registration timer. (Ex. 1001, 3:4-7.) The patent explains that, for this reason, the service interruption duration of the user depends on the duration of the registration cycle of the user. (Id., 3:47-61.) A longer registration cycle could result in a longer service interruption to the user, but a short cycle could result in excessive re-registrations. (Id., 3:42-61.) (Ex. 1002, Decl. 61.) The 617 patent purports to address S-CSCF failures by restoring service processing by an S-CSCF without requiring re-registration. (See Ex. 1001, 3:65-67.) In the proposed method, the S-CSCF stores data for restoring a user service request on the HSS during registration. If that S-CSCF fails, the stored data may then be retrieved from the HSS and used by a newly-assigned S-CSCF to allow service to continue without requiring a new registration. (Id., 4:6-20.) (Ex. 1002, 12

16 Decl. 62.) U.S. Patent 8,719,617 The first step in the claimed procedure is to back up the data that might be needed in the event of an S-CSCF failure on the HSS. To do so, the 617 patent uses the same steps and the same messages as the prior art registration process, described above, but with minor modification. These steps are depicted in Figure 5, which shows the registration flow according to an embodiment of the present invention (highlighted in color): (Ex. 1001, 7:24-25, Fig. 5). This process is almost identical to the prior art 13

17 registration process, depicted in Figure 1, with step 16 slightly modified. (Id., 7:24-29, Fig. 1.) At step 16, as in the prior art procedure, the S-CSCF sends an SAR message including the S-CSCF and user identities to request the HSS to record[] the address of the S-CSCF with which the user registers. (Id., 2:16-21, 2:35-36.) However, the SAR message also includes a new field containing the necessary data which is required when the user service processing is restored, which the HSS stores. (Id., 7:29-33 ( AVP User-Backup-Data ).) The so-called necessary data (or restoration data as in the claims) is now backed up to the persistent storage of the HSS and available to be used if needed. (Ex. 1002, Decl. 1002, ) After registration, the S-CSCF may not be able to set up a subsequent call due to failure of the S-CSCF. Figure 7a (annotated below) shows a scenario in which the UE is the called party (mobile termination) and the I-CSCF in the user s network cannot contact the S-CSCF assigned to the user: 14

18 (Ex. 1001, 13:18-46, Fig. 7(a).) After receiving the request to set up a call, the I- CSCF determines which S-CSCF the UE is registered to by querying the HSS with an LIR message (steps 2 and 3). (Id., 13:25-27, Fig. 7(a).) If the I-CSCF determines that the assigned S-CSCF (S-CSCF1) has failed, it assigns a new one (S-CSCF2) using the same prior art procedure using UAR/UAA or LIR/LIA messages described above (steps 4-6). (Id., 13:29-39.) The S-CSCF2 then interrogates and acquires the subscription data and the backup data of the called user from the HSS using SAR/SAA messages. (Id., 13:54-58.) (Ex. 1002, Decl. 15

19 65.) U.S. Patent 8,719,617 Figures 6(c) and (d) and 7(b) and (c) depict a third type of failure situation in which the S-CSCF first fails and then restores from a failed status, but the service data recorded by the S-CSCF is lost. (Ex. 1001, 12:36-38.) Figure 7(c) (annotated) shows this flow in a mobile termination scenario: 16

20 (Id, Fig. 7(c).) This scenario uses the same procedures described above to determine which S-CSCF is assigned to the user (i.e., LIR/LIA messages) and to retrieve the backed-up data at the S-CSCF, but there is no need to assign a new S- CSCF. (Id., 14:3-19.) (Ex. 1002, Decl. 66.) C. Summary of the Prosecution History The 617 patent issued from U.S. Patent Appl. No. 12/428,810, filed on October 31, 2011, which is a continuation of U.S. Patent No. 8,069,365 ( 365 patent ), filed on April 23, 2009, which is a continuation of PCT/CN2007/070943, filed on October 23, The 617 patent claims priority to two Chinese patent applications: (1) CN , filed October 24, 2006; and (2) CN , filed August 10, The applicants originally filed 28 claims, and the Examiner rejected all 28 claims on obviousness-type double patenting grounds in light of the 365 patent. (Ex. 1006, 6/17/13 Office Action at 2-6.) The Examiner also rejected claims 16 and 18 as anticipated by S , a proposal submitted to the 3GPP SA Working Group 2, described in more detail below. (Ex. 1006, 6/17/13 Office Action at 2-6.) Claim 16 was directed to an I-CSCF with specialized modules adapted to... judge... whether a serving CSCF (S-CSCF) currently providing a service for a user fails or not, assign a new S-CSCF for the current user if the S- CSCF had failed, and forward the session setup request to the newly assigned S- 17

21 CSCF after finishing assigning the new S-CSCF. (Id.) The Examiner found each of these limitations disclosed in S (Id. at 3-5.) Claim 18 added modules adopted to interrogate a capability requirement and assign the new S-CSCF to the user according to the capability requirement from a set of redundant S-CSCFs, which the Examiner also found to be disclosed in S (Id. 5-6.) In short, the Examiner found that S disclosed all limitations related to assignment of a new S-CSCF to a user in the event of a failure of the original S-CSCF. (Ex. 1002, Decl ) The applicants canceled all 28 claims and submitted ten new claims, each of which required (unlike original claims 16 and 18) receiving restoration data used for restoring the service that failed from the storage entity, where the restoration data had been stored by the previous S-CSCF. (Ex. 1027, 11/18/13 Reply.) The Examiner rejected eight of the ten claims on double-patenting grounds, and found that the remaining two claims (issued claims 4 and 10would be allowable if written in independent form. (Ex. 1028, 12/31/13 Office Action.) The applicants also filed a terminal disclaimer, and the Examiner allowed the claims. (Ex. 1029, 1/29/14 Terminal Disclaimer.) (Ex. 1002, Decl. 70.) Though the S proposal was before the Examiner during prosecution, the other references cited in this Petition were not. This Petition applies S in the same way that the Examiner applied it to original claims 18

22 16 and 18, i.e., as anticipating the process of selecting a new S-CSCF when the original S-CSCF fails. The Examiner did not have any references before him that disclosed storing restoration data during registration and then retrieving that restoration data, upon failure of the S-CSCF, in order to restore service to the user. As discussed below, Phan-Anh discloses that storing and retrieving procedure. (Ex. 1002, Decl. 71.) VI. CLAIM CONSTRUCTION The challenged claims in inter partes review should be given their broadest reasonable construction in light of the specification. 37 C.F.R (b). Under this standard, any claim term not explicitly defined in the specification should be given a broad meaning. In re ICON Health & Fitness, Inc., 496 F.3d 1374, 1379 (Fed. Cir. 2007). A. restoration data / restoring data The broadest reasonable interpretations of the terms restoration data wherein the restoration data is stored by the previous S-CSCF and restoring data are their ordinary and customary meanings. 2 2 Claim 5 requires restoration data wherein the restoration data is stored by the previous S-CSCF, and then later refers to receiv[ing] the restoring data. (Ex. 1001, claim 5.) The term restoring data appears to be a typographical error and restoration data may have been intended. In any event, restoring data is a 19

23 In the pending litigation between the parties, Patent Owner has asserted that these terms require a specific construction. In particular, Patent Owner proposes that the terms should be construed as information necessary for the S-CSCF to handle traffic for a registered user, which includes at least a SIP URL of a P-CSCF assigned for a user device and a contact address of the user device. 3 (Ex. 1012, Joint Claim Construction Statement, at 5 ( Joint Claim Chart ).) This is the same meaning that the Patent Owner proposes for a different set of terms in the 365 parent application, necessary data which is required when a user service processing is restored, necessary data, and backup necessary data. (Id., at 2-3.) If the Patent Owner were to pursue the same or similar construction in this proceeding, it should be rejected. The Patent Owner improperly seeks to import limitations into the claims through its constructions. But the patent specification does not contain any lexicography through which the inventors sought to define the shorthand reference to restoration data wherein the restoration data is stored by the previous S-CSCF. (Ex. 1002, Decl. 73 n.2.) 3 The 617 patent incorrectly refers to the address of the P-CSCF as a SIP URL. The correct term is SIP URI. However, these terms were sometimes used interchangeably during the development of IMS, and the term SIP URL can be found in some of the early version of the standards. (Ex. 1002, Decl. 74 n.3.) 20

24 terms. There is therefore no basis to deviate from the ordinary and customary meaning of these terms. (Ex. 1002, Decl. 75.) Moreover, the limitations that Patent Owner seeks to import into the terms (in its proposals for litigation) are found in dependent claims 4 and 10. Importing these limitations into the restoration data terms would render claims 1 and 7 identical in scope to their dependent claims, and violate the doctrine of claim differentiation. (Ex. 1002, Decl. 76.) Ariosa Diagnostics v. The Board of Trustees of the Leland Stanford Junior University, IPR , Paper 40, at (PTAB Nov. 19, 2014). VII. GROUNDS FOR CHALLENGE This Petition, supported by the Declaration of Mr. Craig Bishop filed herewith, demonstrates that there is a reasonable likelihood that Petitioners will prevail with respect to at least one challenged claim and that each of the challenged claims is not patentable. See 35 U.S.C. 314(a.) Mr. Bishop has been a communications specialist for twenty-six years. Prior to starting his consulting firm in 2013, he worked for Samsung, beginning in 1996 as Senior Standards Engineer and eventually became Director of Standards and Industry Affairs. During his tenure at Samsung, he was involved in many different 3GPP and ETSI committees working on GPRS, UMTS, and IMS specifications. (Ex. 1002, 2-11.) 21

25 At the time of the 617 patent, Mr. Bishop was working in, and had extensive expertise in IMS and core network technology. In particular, Mr. Bishop was an active delegate in the 3GPP Service and System Aspects Working Group 2 from , working on the IP Multimedia Subsystem. The work required a sound working knowledge of the core IMS specifications, as well as other 3GPP IMS and IETF (SIP) specifications, to ensure effective participation in meeting discussions, assessment of third party contributions, and provision of implementation guidance to Samsung developers. (Ex. 1002, Decl. 6.) From 2008 until 2011, Mr. Bishop was a member of 3GPP SA1, initially focusing on IMS issues, though later contributing across all topics of relevance to Samsung. (Ex. 1002, Decl. 7.) Over the course of his work with 3GPP SA2 and SA1 between 2006 and 2010, Mr. Bishop authored and submitted 99 meeting contributions. Mr. Bishop also served as the main Samsung contact in 2009 on VoLTE issues, working with to specify the IMS profile for voice and SMS that was later to become GSMA Permanent Reference Document IR.92. Mr. Bishop is a named inventor on 18 patents related to IMS and core network. (Ex. 1002, Decl ) Pursuant to Rule (b)(4)-(5), specific grounds for finding the challenged claims invalid are identified below and discussed in the Bishop Declaration. 22

26 A. Overview of Prior Art U.S. Patent 8,719,617 As explained above, the 617 patent is directed to a recovery system and methods in which a particular server node (called an S-CSCF) stores restoration data to the HSS; a new S-CSCF is assigned to the user if the original S-CSCF fails; and the new S-CSCF retrieves the stored restoration data so that processing can continue. (Ex. 1002, Decl. 77.) There was nothing new about the 617 patent technique. As Mr. Bishop explains, the 617 patent claims are nothing more than a straightforward application of well-known checkpointing type recovery techniques to IMS networks. Checkpointing is a basic recovery technique that has been known for decades. For example, in 1982, Dr. Daniel Siewiorek explained in his textbook The Theory and Practice of Reliable System Design that In checkpointing, some subset of the system state is saved at specific points (the checkpoint) during process execution. The information to be stored is the subset of system state (data, programs, machine state) that is necessary to the continued successful execution and completion of the process past the checkpoint, and which is not backed up by other means. (Ex. 1013, at 170.) Checkpointing is most often implemented in software and requires little or no extra hardware. (Id.) (Ex. 1002, Decl. 79.) 23

27 Checkpointing and similar recovery techniques have been used in cellular and other types of networks since long before the 617 patent. To provide just a few examples: U.S. Patent No. 6,108,300, filed August 25, 1997, describes a recovery technique for network devices. The primary network device sends configuration commands to secondary network device so that secondary network device 310 may mirror the configuration of 300 for the purpose of substituting for primary network device 300 in the event that primary network device 300 fails. (Ex. 1014, Abstract, 6:43-54.) U.S. Patent No. 6,885,861, filed August 24, 2001, describes a solution which facilitates mobility and service recovery when there is a failure in a user s terminal. (Ex. 1015, 4:14-19.) [T]the information necessary for providing mobility and service recovery for users communication services is maintained in a server, such as the HSS. (Id., 4:20-23, 6:10-15.) The HSS sends a message to the new terminal that includes information necessary for the communication services to be received by the new user terminal. (Id., 6:44-51.) U.S. Patent No. 6,963,996, filed April 30, 2002, describes a recovery procedure for failed Web servers such that data communications 24

28 between a client and server need not be repeated when a such a failure occurs. (Ex. 1016, 1:11-19.) A session integrity proxy records requests sent by the web client 104 and/or responses sent by the web server 106. (Id., 4:65-67.) When a failure is detected at the web server 106, the session integrity proxy 102 will restore some or all of the requests and responses recorded during the session to another web server 106. (Id., 5:12-15.) U.S. Patent No. 6,408,182, filed July 16, 1999, describes an architecture for mobile switching centers ( MSC ) in GSM in which mobile communications are sent to a backup MSC when the primary MSC fails. (Ex. 1017, 1:58-2:7.) The backup MSC then fetch[es] the subscriber data from the subscriber s Home Location Register (HLR) (the database of subscriber information in GSM) and stores it at the backup MSC. (Id., 4:4-9.) (Ex. 1002, Decl. 81.) Not surprisingly, the same concept was proposed for the All-IP network that preceded IMS and for the earliest IMS more than five years before the priority date of the 617 patent. For example, as discussed below, Phan-Anh, originally assigned to Nokia, discloses storing data related to the location of the user in the HSS during registration and retrieving it to restore processing if an S-CSCF failed. 25

29 (Ex. 1002, Decl. 82.) U.S. Patent 8,719,617 Similarly, multiple prior art submissions to 3GPP proposed the same concept for assigning a new S-CSCF to the user in the analogous situation when the first S-CSCF failed and was replaced (rather than failed and restarted). For example, in 2002, Ericsson suggested this procedure in S , submitted to the SA Working Group 2 for discussion at the meeting held on October 14-18, (Ex at 2-3 ( An assigned S-CSCF could be down when contacted by an I-CSCF. Further requests from the I-CSCF to the HSS (Cx-Query or Cx- Location-Query) would result in the same S-CSCF name. The I-CSCF should have the possibility to ask explicitly for the capabilities for the selection of a new S- CSCF.... Re-assignments of S-CSCF due to failures in S-CSCFs shall take place both during re-registrations and session initiations to unregistered users. ).) Huawei subsequently proposed a more detailed procedure in early 2006 in S , as discussed below, but those details were simply an application of the known Cx interface messages to Ericsson s proposal. (Ex. 1002, Decl. 84.) Finally, Nokia Siemens Networks filed a European patent application covering the very same restoration procedure as disclosed in the 2006 Chinese application to which the 617 patent claims priority on the same day that the Chinese application was filed. (See Ex. 1011, Cover and claim 1.) This simultaneous invention further confirms the obviousness of the claims. 26

30 B. Ground 1: Claims 1, 5, and 7 Are Invalid As Obvious Over the Combination of Phan-Anh and S Claims 1, 5, and 7 are obvious over the combination of Phan-Anh in view of S As discussed above, S was cited by the Examiner during prosecution as anticipating two of the original claims of the 617 patent application. There the Examiner found that, just like the two rejected claims, S disclosed an I-CSCF adapted to judge... whether a serving CSCF (S- CSCF) currently providing a service for a user fails or not, assign a new S-CSCF for the current user if the S-CSCF had failed, and forward the session setup request to the newly assigned S-CSCF after finishing assigning the new S-CSCF. (Ex. 1006, 6/17/13 Office Action at 2-6.) The two rejected claims were canceled and replaced with new ones that had new limitations in which the S-CSCF received restoration data used for restoring the service that failed from the storage entity, where the restoration data had been stored by the previous S-CSCF. (Ex. 1027, 11/18/13 Amendment at 2-4.) As explained below, Phan-Anh (which was not before the Examiner during prosecution), in combination with S , teaches the purportedly novel limitations directed to assigning a new S-CSCF and the storing and retrieving restoration data. (Ex. 1002, Decl ) Phan-Anh was filed on March 12, 2001, published on September 12, 2002 as U.S. Patent Publication No. US A1, and is prior art to the 617 patent under 35 U.S.C. 102(a) and (e). Phan-Anh incorporates TR by reference 27

31 in its entirety. (Ex. 1003, 1:16-20.) TR is a 3GPP Technical Report uploaded to the public 3GPP server on June 28, S is a 3GPP Tdoc uploaded to the public 3GPP server on January 10, As discussed below, TR and S are prior art to the 617 patent under 35 U.S.C. 102(b). (See Ex. 1002, Decl. 89.) As explained below, Phan-Anh discloses storing restoration data on the HSS during registration and retrieving that data to restore a service after an S-CSCF fails and restarts. S discloses assigning a new S-CSCF when the previously-assigned S-CSCF fails. (Ex. 1002, Decl. 90.) As shown below, the figures found in both references as compared to the figures in the 365 patent specification, demonstrate that Phan-Anh and S contained substantively identical disclosures to those in the 365 patent. It is therefore not surprising that the 365 patent claims read on these references, as demonstrated in the element by element analysis of the Grounds Sections. 1. Overview of Phan-Anh Like the 617 patent, Phan-Anh teaches a recovery procedure to be used when the S-CSCF restarts and has lost data associated with the user. Phan-Anh was filed over five years before the 617 patent, when IMS was in the early stages of development, demonstrating how straightforward, simple, and universally wellknown the checkpointing concept was. (Ex. 1002, Decl. 91.) 28

32 Phan-Anh incorporates TR by reference in its entirety. (Ex. 1003, 1:16-20.) TR discloses that for the purpose of the registration procedures... [t]he serving CSCF [S-CSCF] understands a service profile and the address of the functionality of the proxy CSCF [P-CSCF], and indicated that after registration, the S-CSCF must store Subscriber information and Proxy address/name. (Ex at and B.4 (table showing Stored Information).) TR also contemplated that the proxy address and name would be stored in the HSS after registration. (Id.) (Ex. 1002, Decl. 92.) With this backdrop, Phan-Anh explains that the network disclosed in the Technical Report [TR ] fails to include any protection of the user s transport address ( TA ), IP address, or location information of a subscriber after a CSCF crash, thereby preventing recovery after a CSCF crash. (Ex. 1003, 1:26-34.) Phan-Anh also notes that the reachability of a subscriber is maintained in two levels, namely, the network element level and the subscriber level. (Id., 2:44-46.) For this reason, [t]he S-CSCF that the subscriber is currently registered to and the TA of the roaming subscriber, which the subscriber provides to the network during Application Level (AL) registration, must be known to and maintained by the network. (Id., 2:46-50.) As Mr. Bishop explains, at the time Phan-Anh was filed, the 3GPP SA2 working group was developing the IMS architecture and considered the IP address of the UE to be the way that the UE 29

33 could be reached by the S-CSCF. SA2 had also specified that the UE address was the only address not stored in the HSS following registration (both S-CSCF and Proxy CSCF addresses were). (Ex. 1002, Decl ; see Ex. 1030, S (later changing contact method from IP address to P-CSCF address).) For this reason, the inventors of Phan-Anh found that the TA of the subscriber therefore should be protected against loss with the same level of security as that for the Serving CSCF (S-CSCF). (Ex. 1003, 4:4-6.) Keeping the current TA of the subscriber ensures that a call made to the subscriber which arrives at the S-CSCF can finally reach the subscriber. (Id., 3:49-53.) (Ex. 1002, Decl. 94.) As Mr. Bishop explains, a person of skill in the art would readily appreciate that Phan-Anh therefore expands the teachings of TR to recovering location information of a subscriber in a mobile network, including the subscriber s TA. (Ex. 1003, 1:38-47; Ex. 1002, Decl. 95.) In one embodiment, the TA, or care of address, is an IP address associated with a mobile node while the subscriber is visiting a particular foreign link. (Id., 3:15-17.) Phan-Anh explains that [t]he TA of the subscriber should be forwarded to the HSS at registration and downloaded from the HSS to the S-CSCF during recovery. (Id., 4:10-12.) Phan-Anh s registration procedure is shown in Figure 4B (annotated with the same color convention used above for the 617 patent): 30

34 Phan Anh U.S. Patent 8,719,617 (Id., Fig. 4B.) In this procedure, as with the 617 patent, a safe copy of the subscriber's TA is forwarded to the HSS for storage and protection. (Id., 4:20-21.) In step 1, the registering subscriber forwards an AL registration request to the S-CSCF including the TA. (Id., 4:35-37.) In steps 2 and 3, the TA and S- CSCF address are forwarded to the HSS, which stores the updated TA and S- CSCF address (in a hard disk, for example, or other non-volatile memory). (Id., 4:37-40.) In step 4, the HSS forwards an AL Location Update acknowledgement to the S-CSCF which stores the TA and subscription profile and other data in step 5. (Id., 4:40-43.) (Ex. 1002, Decl. 95.) 31

35 TR describes the data that is stored locally at the S-CSCF during registration. Figure B.2 depicts the second part of the registration, which is the same as Phan-Anh Figure 4B: (Ex at 51, Fig. B-2.) At H2, the S-CSCF initiates the download of the subscriber profile and the HSS provide[s] the serving CSCF with the requested subscriber profile, which the S-CSCF stores. (Id. at ) At the end of the registration procedure, the S-CSCF has stored the HSS address and name, the subscriber information, and the proxy (P-CSCF) address and name. (Ex. 1002, Decl. 96.) Phan-Anh Figure 4A (color added) shows how [t]he TA and other data can then be restored to the S-CSCF upon the earlier loss of the data by the S-CSCF : 32

36 Phan Anh U.S. Patent 8,719,617 a (Id., 4:23-25, Fig. 4A.) In steps 1 and 2, [a]n incoming call from an REP (Remote End-Point) is received by the S-CSCF, but the S-CSCF fails to find the subscriber s TA. (Id., 4:26-28.) In step 3, the S-CSCF initiates the restoration of the subscriber's TA (and possibly other data) from the HSS. (Id., 4:28-31.) In step 4, the call is then routed to the subscriber using the recovered TA. (Id., 4:33-34.) (Ex. 1002, Decl. 97.) 2. Overview of S S describes reassignment of a new S-CSCF after the original S- CSCF has failed. It focuses on the exemplary situation when the pre-assigned S- CSCF is unavailable during the terminated call procedure, i.e., when the UE is the called party (also known as mobile termination ). (Ex at 1.) (Ex. 1002, Decl. 98.) 33

37 Ericsson had proposed the concept of re-assignment after S-CSCF failure years before in S , submitted to the same Work Group SA2 in (Ex at 2-3.) Ericsson explained that [a]n assigned S-CSCF could be down when contacted by an I-CSCF, and [f]urther requests from the I-CSCF to the HSS for the name of the S-CSCF assigned to the user would result in the same S-CSCF name, which had failed. Ericsson proposed that [r]e-assignments of S-CSCF due to failures in S-CSCFs shall take place both during re-registrations and session initiations to unregistered users. (Id.) When Huawei subsequently proposed a more detailed procedure in early 2006 in S , the proposal was simply an application of the known Cx interface defining messages between the S-CSCF and I-CSCF and the HSS to Ericsson s proposal. (Ex. 1002, Decl. 99.) S explains that [t]he existing standards only consider... reassignment [of an S-CSCF] during the registration procedure, but [i]t will take a long time and the caller may give[] up the call during the reassignment procedure. (Ex at 1.) S suggested the same idea as the 617 patent enabl[ing] the reassignment feature also in the terminated call procedure by modify[ing] the existing Cx interface to allow the I-CSCF to explicitly request the S-CSCF capabilities from HSS. (Id. at 2.) (Ex. 1002, Decl. 100.) This reassignment procedure is depicted in the Figure below (color added): 34

38 S U.S. Patent 8,719,617 (Ex. EX-S2 at 2.) S describes the procedure as follows: 1. When I-CSCF received a terminated SIP message, it queries the HSS using the LIR/LIA messages described above to get the previous assigned S-CSCF name. 2. Using that S-CSCF name, [the] I-CSCF... judges[s] whether the pre-assigned S-CSCF is still available. 35

39 3. When [the] I-CSCF judge[s] that the pre-assigned S-CSCF is unavailable, it uses another LIR/LIA query to the HSS to retrieve the related S-CSCF capability. 4. The I-CSCF then selects a new S-CSCF2 and forward[s] the SIP message to S-CSCF2. 5. [T]he new S-CSCF it will send the Cx-SAR message to [the] HSS, and the HSS will record the new S-CSCF assigned to the user. 6. All calls to the UE will route to that new S-CSCF. (Id.) S also noted that the impact[] of the implementation to the existing standard may be small. (Id.) (Ex. 1002, Decl. 101.) 3. The 3GPP Documents Qualify As Prior Art to the 617 Patent TR , S , TS , SP , TS , S , and S (Exhibits , 1007, 1008, 1010, 1018, and 1030) are prior art because each was available to the interested public well before October 23, 2006, which is one year prior to the U.S. filing date of the 617 patent. The touchstone of determining whether a reference constitutes a printed publication is public accessibility. Kyocera Wireless Corp. v. ITC, 545 F.3d 1340, 1350 (Fed. Cir. 2008). A reference is publicly accessible if it was disseminated or otherwise made available to the extent that persons interested and ordinarily skilled in the subject matter or art exercising reasonable diligence, can 36

40 locate it. Kyocera, 545 F.3d at (finding public accessibility where ETSI did not impose restrictions on ETSI members to prevent them from disseminating information about the standard to non-members ). As discussed above, Mr. Bishop spent years working on 3GPP standardization and is familiar with the publication practices of 3GPP from 1998 to 2006 and beyond. (Ex. 1002, Decl ) Mr. Bishop explains that it has been the practice of the 3GPP since 1998 to make standards proposals and draft standard specifications publicly available on its FTP website, without password restriction, before, during, or shortly after a working group meeting for which the documents were intended, and to store them there for an indefinite period thereafter. (Id., ) By navigating 3GPP s public FTP website and accessing the hyperlinks on the site, or by executing a simple Google search, an interested member of the public could have downloaded each of the references of Exhibits , 1007, 1008, 1010, and 1018 without restriction. (Id., 43.) See LG Elecs. v. Core Wireless Licensing S.A.R.L., IPR , Paper 7, at (PTAB Apr. 1, 2016). Mr. Bishop regularly downloaded 3GPP documents from the 3GPP public FTP website in preparation for meetings. (Ex. 1002, Decl. 5-7, 25.) Mr. Bishop also explains that the date and time each document was publicly available can be determined, for example, by navigating to or searching for the appropriate page on the 3GPP FTP web site and viewing the date and time the 37

41 specific document was uploaded. (Id., 43; Ex (3GPP document explaining that each working group has a specific documents area allocated on the 3GPP ftp server... where you will find the all meeting documents including... contributions (TDocs) relating to that group. ; Ex (proposals and standards specifications on the public server,... will now get an upload date/time-stamp of the new upload, which can be relied upon to indicate when the upload occurred. ).) The dates that Exhibits , 1007, 1008, 1010, 1018, and 1030 were uploaded are shown by the screen shots of the FTP site pages to which they were uploaded: TR (Ex. 1004) was publicly available no later than July 24, The zip file zip (containing TR ) was loaded to the page for TR at the 3GPP FTP site on July 24, 2000 at 9:50 am. (Ex (screen capture).) (Ex. 1002, Decl ) S (Ex. 1005) is a proposal that was available at the January 16-20, 2006 meeting #50 of the 3GPP Service and System Aspects 2 Working Group (SA2) in Budapest, Hungary, which Mr. Bishop attended. The zip file S zip (containing S ) was loaded to the loaded to the S2#50 working group meeting site on 38

42 January 10, 2006 at 12:50 pm. (Ex at 3.) (Ex. 1002, Decl ) TS (Ex. 1007) was publicly available no later than December 7, 2005, the date on which it was loaded to the corresponding 3GPP FTP website. The zip file zip (containing TS ) was loaded to the site on December 7, 2005 at 7:59 am. (Ex ) (Ex. 1002, Decl ) SP (Ex. 1008) is a proposal that was available at the June 26-28, 2000 meeting #8 of the 3GPP SA working group in Düsseldorf, Germany. SP was publicly available no later than June 26, 2000, the date on which it was loaded to the SP#8 working group meeting site. The zip file containing SP was loaded on June 26, 2000 at 11:57 am. (Ex. 1024) (Ex. 1002, Decl ) TS (Ex. 1010) was publicly available no later than December 23, 2005, the date on which it was loaded to the corresponding 3GPP FTP website. The zip file zip (containing TS (Ex. 1007)) was loaded to the site on December 3, 2005 at 7:02 am. (Ex ) (Ex. 1002, Decl ) S (Ex. 1018) is a proposal that was available at the October 14-18, 2002 meeting #27 of the 3GPP S2 working group in Beijing, 39

43 China. S was publicly available no later than October 23, 2002, the date on which it was loaded to the SA2#27 working group meeting site. The zip file S zip (containing S ) was loaded on October 23, 2002 at 4:19 pm. (Ex ) (Ex. 1002, Decl. 1002, ) S (Ex. 1030) is a change request that was available at the August 27-31, 2001 meeting #19 of the 3GPP S2 working group in Sophia-Antipolis, France. The zip file S zip (containing S ) was loaded to the loaded to the S2#19 working group meeting site on September 4, 2001 at 9:36 am. (Ex at 6.) (Ex. 1002, Decl ) 4. Claim 1 (a) In a serving call session control function (S-CSCF), a method for realizing an Internet protocol multimedia subsystem (IMS) disaster tolerance, the method comprising This preamble does not limit the claim under the claim s broadest reasonable interpretation. To the extent the Board considers the preamble to be limiting, Phan-Anh teaches a method for realizing an Internet protocol multimedia subsystem disaster tolerance in a serving call session control function (S- CSCF). For example, Phan-Anh teaches a technique for recovering location 40

44 information of a subscriber in a mobile network, including the subscriber s TA [Transport Address] and the (S-CSCF) address, after Call State Control Function (CSCF) crashes and after reset situations of a network element realizing CSCF functionality after the S-CSCF and restarts, during which the S-CSCF loses data. (Ex. 1003, 1:7-13, 1:38-47.) The lost data including the subscriber s TA may be restored to the S-CSCF from the data stored in the S-CSCF. (Id. at Abstract.) Phan-Anh explains that [k]eeping the current TA of the subscriber ensures that a call made to the subscriber which arrives at the S-CSCF can finally reach the subscriber. (Id., 3:51-53.) (Ex. 1002, Decl. 94.) S also satisfies the preamble. S proposes introduc[ing] the reassignment in the terminated call procedure to give [the] operator more flexibility to recover from error especially in some case[s]. (Ex at 2.) (Ex. 1002, Decl. 107.) (b) receiving a service request of a user forwarded by an interrogating CSCF (I-CSCF) when it is determined that a previous S-CSCF failed in providing a service to the user S discloses this limitation. The figure of S (color added) shows S-CSCF reassignment during the terminating call procedure : 41

45 S U.S. Patent 8,719,617 (Ex. EX-S2 at 2.) In this figure, the I-CSCF has determined that the originallyassigned S-CSCF1 is unavailable e.g., due to a failure and assigns S-CSCF2 to the user using the LIR/LIA messages described above. The I-CSCF then forwards the Invite to the newly-assigned S-CSCF2. (Id.) (Ex. 1002, Decl. 108.) Phan-Anh also discloses that the S-CSCF receives a service request of the user e.g., a call set up request from an I-CSCF, as does the 617 patent. Figure 4A shows the restoration procedure when a subscriber is called (i.e., mobile termination); it is juxtaposed to the mobile termination restoration procedure in 42

46 Figure 7(a) of the 617 patent below (color added) and demonstrates that Phan-Am contained substantively identical disclosure to that contained in the 617 patent: Phan Anh 617 Patent 43

47 (Ex. 1003, Fig. 4A; Ex. 1001, Fig. 7(a).) In step 1 of Figure 4A (in purple), [a]n incoming call from an REP (Remote End-Point) i.e., a service request of the user is received by the S-CSCF. (Ex. 1003, 4:26-28.) (Ex. 1002, Decl. 109.) Figure 5 of Phan-Anh (color added) also shows another embodiment disclosing the same claim element: Phan Anh (Ex. EX-PHAN at Fig. 5.) At step 2, the I-CSCF in the home network of the user receives an incoming call i.e., a service request of the user. (Ex. 1002, Decl. 110.) 44

48 (c) U.S. Patent 8,719,617 sending a request for subscription data of the user and restoration data stored in a storage entity and used for restoring the service that failed to the user Phan-Anh discloses sending a request for subscription data of the user i.e., the subscription profile and restoration data i.e., the transport address (TA) of the user stored in a storage entity and used for restoring the service that failed to the user. Phan-Anh Figure 4A and 617 Figure 7(a) (color added) both show restoring the restoration data from the HSS: Phan Anh 45

49 617 Patent U.S. Patent 8,719,617 (Ex. 1003, Fig. 4A; Ex. 1001, Fig. 7(a).) Like the HSS disclosed in the 617 patent, the HSS in Phan-Anh has non-volatile memory and is part of the 3G All-IP mobile network. (Ex. 1003, 4:38-40, Fig. 1 ( the architecture of a 3G All-IP mobile network, including an HSS), 2:16-17.) The HSS in Phan-Anh is a storage entity in a network. (Ex. 1002, Decl. 111.) Phan-Anh explains that, after the S-CSCF has failed to find the subscriber s transport address ( TA ), the S-CSCF initiates the restoration of the subscriber's 46

50 TA (and possibly other data) from the HSS. (Ex at 4:10-12, 4:28-31 ( The TA of the subscriber should be... downloaded from the HSS to the S-CSCF during recovery. ).) As discussed above, the TA, or care of address, is an IP address associated with a mobile node, and storing it ensures that a call made to the subscriber which arrives at the S-CSCF can finally reach the subscriber. (Id., 3:15-17, 3:49-53.) (Ex. 1002, Decl. 112.) During restoration, the S-CSCF will also download the user s subscription profile, i.e., the subscription data of the user, which the 617 patent also calls the user profile. (Ex. 1003, 5:28-31; Ex. 1001, 617 patent, 11:13-19 ( user profile information element is valued as the subscription data of the user. ); Ex. 1002, Decl. 113.) Phan-Anh explains that during registration, after the HSS stores the TA, the S-CSCF stores the TA and subscription profile and other data in step 5. (Ex. 1003, 4:41-43; Fig. 5B, step 5.) TR further explains the S- CSCF obtained the subscription profile by initiat[ing] the download of the subscriber profile from the HSS and the HSS provid[ing] the serving CSCF with the requested subscriber profile. (Ex at 51-52, (identifying data stored at the S-CSCF after registration).) When the S-CSCF retrieves the TA of the user from the HSS during restoration in Phan-Anh, the HSS also send the subscription profile of the user to the S-CSCF so that the S-CSCF will know how to process services requests for that user. (Ex. 1003, Fig. 4A, step 3 and 5:

51 ( the S-CSCF has no memory of what mobile stations (MSs) were registered with the S-CSCF after a crash and therefore trigger[s] a profile download ).) In this manner, the S-CSCF interrogates and acquires the subscription data of the user (i.e., the subscription profile) and the restoration data (i.e., the transport address or TA). (Ex. 1002, Decl. 113.) It would have been apparent to a person of ordinary skill in the art that this same procedure could be used to retrieve the restoration data stored in the HSS after failure of the original S-CSCF and assignment of a new S-CSCF. Phan-Anh discloses the checkpointing technique by which restoration data is stored and later retrieved by an S-CSCF. A person of ordinary skill in the art would have understood that this procedure, as disclosed in Phan-Anh, could be used to perform this step, even if a different S-CSCF performed it. (Ex. 1002, Decl. 114.) S also discloses retrieving data from the HSS to continue processing. As shown below, the figure in S (color added) shows that the new S-CSCF sends an SAR message to the HSS to record the new S-CSCF, and the HSS returns an SAA message: 48

52 S U.S. Patent 8,719,617 (Ex at 2; Ex. 1001, 13:54-56, Fig. 7(a).) When combined with Phan-Anh, S discloses interrogating and acquiring the restoration data from the HSS. (Ex. 1002, Decl. 115.) To the extent that Patent Owner argues for a narrow construction of the restoration data terms (e.g., requiring that they include a SIP URL of a P-CSCF assigned for a user device and/or a contact address of the user device), Phan-Anh discloses this limitation. Phan-Anh expressly incorporates by reference TR , which (like the prior art described in the 617 patent) requires that, during 49