US 5561706

I'll search for the specific patent number and any related CAFC 2026 docket activity.

Let me run more targeted searches for the patent and any 2026 Federal Circuit activity.

Let me check specifically for any 2026 activity involving this patent or patentee.

US Patent 5,561,706 — Summary

Sourcing note: I queried general web search (which indexes Google Patents, CAFC opinions/orders, district court filings, and IP law firm bulletins). I do not have a direct, credentialed connection to the USPTO PatentCenter or the CAFC clerk's live docket system, so the "2026 docket" portion of your request is a negative finding based on search results, not an authoritative docket query. I flag that explicitly below.

Bibliographic data (from the Google Patents record for US5561706A)

Abstract (as issued): A method and apparatus for managing a communications network for mobile users, each with a personal identification number (PIN/PID). A network of communications switches connects calls between mobile users using the PIN as the address. A plurality of billing authorities maintain service profiles and communicate with the switches; a plurality of location authorities track which switch, if any, each assigned user is logged onto and permit logging onto only one switch at a time. A user may subscribe to multiple billing authorities and hold multiple service profiles; a billing code entered by the user designates the billing authority for a call. The billing authority forwards its service profile to the switch if not already stored there. Each switch includes a table storing a limited number of individual service profiles, with the table linked to several queue lists indicating each profile's status.

Plain-language overview of each independent claim

• Claim 1 — A method for letting a mobile user access an RF communications switch. The system has many interconnected RF switches, many billing authorities, and many location authorities. The switch (a) receives the user's personal identification number, (b) receives a billing code from the user that picks which billing authority holds that user's service profile (different billing authorities may hold the profile or a second profile for the same user), (c) requests the service profile from the designated billing authority, (d) stores the received profile in memory, and (e) gives the user access to the switch.

• Claim 10 — A method for providing mobile-user access in which the user's PIN is arithmetically compressed to a unique integer index value; the service profile is stored in the database record pointed to by that index value; and access is provided according to the stored service profile.

• Claim 15 — A method for controlling calls from mobile users across interconnected switches. The local switch receives the user's identification number, searches its own service-profile database, and if the profile is absent, requests it from the billing authority indicated by a billing-authority designator received from the user, and requests location authorization from the location authority indicated by a location-authority designator received from the user. The user is logged on only after both the profile and the location are received. The database search is done by arithmetically compressing the identification number to an integer value that points to the profile's location in the database.

• Claim 18 — A call-completion method. A source user logged onto a first switch supplies the destination user's personal identification code. The system determines whether the destination is already logged onto that same first switch; if not, it identifies the location tracking authority assigned to the destination's code, requests from that authority the identity of the destination switch where the user is currently logged on, receives that identity, and routes the call there.

(Dependent claims add, e.g., arithmetic PIN compression into the index table (cl. 2), overwriting stale/inactive profiles when switch capacity is exceeded (cl. 3, 11), location requests to the location authority (cl. 4, 13), denial of access when the user is on another switch (cl. 5, 14), destination lookup and routing (cl. 6, 12), destination-access restrictions per the source's profile (cl. 7), denial of log-on when outside the profile's valid service area (cl. 8), local-profile-first lookup (cl. 9), multiple billing authorities per user (cl. 16), forced log-off from a second switch (cl. 17), and PINs independent of any physical unit (cl. 19).)

Litigation posture and CAFC 2026 search

I found no 2026 CAFC docket, opinion, Rule 36 judgment, or scheduled oral argument involving US 5,561,706 or Fenner Investments. Searches for "5561706"/"5,561,706" combined with 2026 docket terms returned only unrelated matters (different patent numbers, and non-patent hits such as Fla. Stat. § 561.706). This is consistent with the patent having expired October 1, 2013, after which infringement appeals would be unlikely.

What is documented for this patent:

• Fenner Invs., Ltd. v. Cellco P'ship, No. 2013-1640 (Fed. Cir. Feb. 12, 2015) (Newman, Schall, Hughes) — affirmed summary judgment of non-infringement of claim 1. The court construed "personal identification number" as "a number separate from a billing code… identifying an individual system user, which is associated with the individual and not the device," and held that statements the inventor made during prosecution (distinguishing Hayes, U.S. 5,210,787, as device-centered) bind the claims regardless of whether the examiner relied on them (citing Microsoft v. Multi-Tech). Source: https://cafc.uscourts.gov/opinions-orders/13-1640 (and Finnegan/Wiley summaries).
• Underlying district case: Fenner Investments, Ltd. v. Cellco Partnership, No. 6:11-cv-00348 (E.D. Tex., Judge Leonard Davis) — claim construction and denial of Verizon's summary judgment (order of July 30, 2013), leading to the stipulated non-infringement judgment.
• The Google Patents record also lists an earlier N.D. Cal. case, 3:05-cv-01987, and a worldwide family-litigation link (Darts-ip).

Uncertainty / caveats:

• The "associated with the individual and not the device" construction is the key limiting holding; any 2026 follow-on activity would most likely be collateral (e.g., a license/ownership dispute) rather than infringement litigation on an expired patent.
• I cannot rule out a very recent or unindexed 2026 CAFC filing. To be authoritative, check the CAFC docket search and USPTO PatentCenter Assignment/Patent Term records directly for application 07/952,998.

Would you like me to attempt a direct lookup on a specific docket (e.g., courtlistener/PACER) to confirm the negative 2026 result?

I'll research litigation involving US Patent 5,561,706 across patent litigation databases.

Let me dig deeper into each case and look for additional suits.

Let me verify the N.D. Cal. case and the 3Com case details.

Litigation Involving U.S. Patent No. 5,561,706

Patent identified: US 5,561,706 ("the '706 patent"), titled "System for managing access by mobile users to an interconnected communications network where a billing authority is identified by a billing code from the user." Application No. 07/952,998; filed and priority date September 29, 1992; granted October 1, 1996; inventor Peter R. Fenner; original assignee Individual; later assigned to Fenner Investments, Ltd. (recorded Oct. 27, 2000). Anticipated expiration: October 1, 2013 (status: Expired–Lifetime).

The '706 patent was asserted in a family of infringement suits brought by Fenner Investments, Ltd. Below are the known matters. Note: I was able to confirm the items below to the level indicated; where a source did not confirm a detail, I say so rather than infer it.

1. Fenner Investments, Ltd. v. [Juniper Networks, Inc.](/litigations/by-defendant/Juniper%20Networks%2C%20Inc.), et al.

(Confirmed by the E.D. Tex. docket record, the May 16, 2006 Markman opinion, and the Feb. 9, 2006 order — all of which name the '706 patent.)

2. Fenner Investments, Ltd. v. [Cellco Partnership d/b/a Verizon Wireless](/litigations/by-plaintiff/Cellco%20Partnership%20d%2Fb%2Fa%20Verizon%20Wireless), et al.

(Confirmed by the E.D. Tex. final judgment, the Report & Recommendation of the Magistrate Judge, and the Federal Circuit opinion below.)

3. Fenner Investments, Ltd. v. Cellco Partnership (Federal Circuit appeal)

(Confirmed by the CAFC opinion and the docket; Fenner Invs., Ltd. v. Cellco P'ship, 778 F.3d 1320.)

4. Additional matters / related litigation (flagging uncertainty)

• Fenner Investments, Ltd. v. 3Com Corp., et al. — U.S. District Court for the Eastern District of Texas, Case No. 6:08-cv-00061, filed February 26, 2008 (Judge Leonard Davis / Magistrate Judge John D. Love). Defendants named on the docket include 3Com Corporation, Foundry Networks, Inc., Extreme Networks, Inc., Netgear, Inc., ZyXEL Communications, Inc., D-Link Systems, Inc., SMC Networks, Inc., Enterasys Networks, Inc., and Tellabs entities. Resolved by dismissals/settlement (final judgment Jan. 11, 2010). Caveat: my sources describe this as Fenner litigation over "network switching technology" and do not expressly confirm that the '706 patent (as opposed to Fenner's related '670 patent) was asserted in this case. Treat the '706 assertion here as unconfirmed.

• Google Patents litigation data for the '706 patent family lists a U.S. case in the U.S. District Court for the Northern District of California, Case No. 3:05-cv-01987 (2005). The source does not identify the parties or the patent(s) asserted, and I could not confirm the parties from the sources retrieved in this session. I therefore cannot state who the parties were or whether the '706 patent specifically was asserted. This is a candidate related matter worth verifying directly via PACER.

Summary

The only confirmed infringement litigation on U.S. Patent No. 5,561,706 is the Fenner Investments campaign:

1. Fenner v. Juniper Networks, et al., No. 2:05-cv-00005 (E.D. Tex., filed Jan. 6, 2005) — asserted '706 and '670; resolved by dismissals/settlements.
2. Fenner v. Cellco/Verizon Wireless, et al., No. 6:11-cv-00348 (E.D. Tex., filed July 6, 2011) — asserted '706 Claim 1 only; final judgment of non-infringement Aug. 9, 2013.
3. Fenner v. Cellco Partnership, No. 2013-1640 (Fed. Cir., decided Feb. 12, 2015) — affirmed non-infringement (778 F.3d 1320).

The '706 patent expired October 1, 2013 and remains "Expired – Lifetime," so no further U.S. infringement actions on it should be available.

Limitations on this report: I reached the tool-step limit before I could run additional targeted searches, so (a) the parties to the N.D. Cal. 3:05-cv-01987 docket and (b) whether the '706 patent (versus the related '670 patent) was asserted in the Fenner v. 3Com, No. 6:08-cv-00061 action remain unverified. I recommend confirming those two items directly against PACER/Unified Patents before relying on them.

I'll verify the structured block's "no PTAB activity" default against public sources before finalizing.

Now let me check specifically for AIA trial activity (IPR/PGR/CBM) and any ex parte reexamination.

Let me confirm with a couple of targeted searches on PTAB filings and reexamination history.

PTAB / AIA Trial Analysis — US 5,561,706

Canonical source: the structured "PTAB proceedings on file" block (USPTO Open Data Portal) returns no AIA trial proceedings for US 5,561,706. I independently searched Google Patents (which flags "Family has litigation" and links three judicial case records — none at the PTAB), Docket Alarm PTAB dockets, and PTAB-focused reporting. I found no IPR, no PGR, and no CBM naming this patent. No ex parte reexamination control number for 5,561,706 surfaced either; the Legal Events in the structured data show only grant, maintenance-fee, assignment, and certificate-of-correction entries — no reexam code.

I flag the limits of that search: I could not query PTAB E2E directly from this environment, so I cannot rule out a petition that was filed and not instituted in a period Docket Alarm's index missed. But three independent roads lead to the same place, so treat "zero AIA trials" as high confidence.

Proceedings overview

Total AIA trial proceedings: 0 — 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution denied.

The bottom-line defensive posture for a defendant today does not come from the PTAB. It comes from two facts that are stronger than any IPR would have been: (1) the patent expired 2013-10-01 and is status "Expired - Lifetime," so there is no forward-looking infringement exposure for any current product; and (2) the only claim ever asserted in litigation, claim 1, was held not infringed under the district court's narrowing construction of "personal identification number," and the Federal Circuit affirmed that judgment in Fenner Investments, Ltd. v. Cellco Partnership, 778 F.3d 1320 (Fed. Cir. 2015). A troll demand letter citing claim 1 against modern PCS/cellular billing functionality is therefore weak on two independent axes — expiry and claim scope — but note that claims 2–19 were never adjudicated by any tribunal, PTAB or court, and were never canceled by the Office.

No AIA trial proceedings to report

There is no IPR, PGR, or CBM number to populate the per-proceeding template. I am not going to manufacture one. What follows is the nearest thing to a "proceeding" history on this patent — the judicial track — clearly labeled as NOT an AIA trial, because it is doing the defensive work that an IPR would otherwise do.

CAFC 2013-1640 — Fenner Investments, Ltd. v. Cellco Partnership (d/b/a Verizon Wireless)

• Type: Federal Circuit appeal from a district court summary judgment — not a PTAB appeal (35 U.S.C. § 319 does not apply; there was no Board decision below).
• Decided: 2015-02-12 — 778 F.3d 1320; 113 U.S.P.Q.2d 1770. Panel: Newman (author), Schall, Hughes.
• Procedural posture: Appeal from the U.S. District Court for the Eastern District of Texas (No. 6:11-cv-00348, Chief Judge Leonard Davis), which granted summary judgment of non-infringement of claim 1 of the '706 patent and entered final judgment on 2013-08-09.
• Issue: Construction of "personal identification number." The district court adopted: "a number separate from a billing code (as construed herein), identifying an individual system user, which is associated with the individual and not the device." It construed "billing code" as "a code separate from the personal identification number (as construed herein), identifying a particular billing authority." Based on those constructions the parties stipulated to non-infringement, preserving Fenner's appeal right.
• Disposition: Affirmed. The court held the specification and prosecution history supported the user-centric construction, that it did not render the invention inoperable, and that claim differentiation could not broaden the claim. Key quote: "[T]he interested public has the right to rely on the inventor's statements made during prosecution, without attempting to decipher whether the examiner relied on them, or how much weight they were given." Slip op. at 9 (citing [Microsoft Corp.](/litigations/by-plaintiff/Microsoft%20Corp.) v. Multi-Tech Sys., Inc., 357 F.3d 1340, 1350 (Fed. Cir. 2004)).
• Why it matters: This is a prosecution-history disclaimer holding. Fenner argued during prosecution that "[t]he present invention, on the other hand, is centered around the mobile user, not the mobile telephone," to overcome an obviousness rejection over U.S. Patent No. 5,210,787 (Hayes). That statement is now the claim scope.
• Links: CAFC opinion PDF — http://cafc.uscourts.gov/opinions-orders/13-1640.opinion.2-10-2015.1.pdf ; summary — https://caselaw.findlaw.com/summary/opinion/us-federal-circuit/2015/02/12/[272789](/patent/272789).html ; practitioner analysis — https://www.finnegan.com/en/tools/fenner-investments-ltd-v-cellco-partnership/analysis.html

E.D. Tex. 6:11-cv-00348 — Fenner Investments, Ltd. v. Cellco Partnership; MetroPCS Communications, Inc.; MetroPCS Wireless, Inc.; MetroPCS Texas, LLC

• Filed: 2011-07-06 (amended complaint 2012-03-29).
• Outcome: MetroPCS entities voluntarily dismissed after settlement (2013); Verizon took claim construction and won. Report & Recommendation of the Magistrate Judge (Doc. 122), adopted by the district court (Doc. 153); final judgment entered 2013-08-09 holding claim 1 NOT INFRINGED. Verizon's invalidity/unenforceability counterclaims were dismissed without prejudice — so validity of claim 1 was never adjudicated.
• Link: Claim construction order (Doc. 136) — https://cases.justia.com/federal/district-courts/texas/txedce/6:2011cv00348/[131039/136](https://assignmentcenter.uspto.gov/search/patent/reelFrameDetail?reelFrame=131039-0136)/0.pdf

E.D. Tex. 2:05-cv-00005 — Fenner Investments, Ltd. v. [Juniper Networks, Inc.](/litigations/by-defendant/Juniper%20Networks%2C%20Inc.) et al. (and companion litigation)

• Type: Patent infringement actions (not AIA trials).
• Defendants across the campaign (per the 2006-05-16 Markman order): Juniper Networks, Nokia, Nortel Networks, Cisco Systems, Ericsson, Telefonaktiebolaget LM Ericsson, Alcatel USA.
• Claim construction: The court construed "service profile" as "a description of services for which a personal identification number (as construed herein) is authorized" — a construction the E.D. Tex. court later carried into the Verizon case.
• Link: https://ipmall.info/sites/default/files/hosted_resources/Markman/pdfFiles/2006.05.16_FENNER_INVESTMENTS_LTD_v._JUNIPER_NETWORKS_INC.pdf

E.D. Tex. (Tyler Div.) — Fenner Investments, Ltd. v. Microsoft Corp.; Nintendo Co., Ltd.; Nintendo of America, Inc.

• Type: Patent infringement action (not an AIA trial).
• Outcome: Adverse rulings in 2008–2009 (Memorandum Opinion 2008-08-22; orders 2009-03-16; Memorandum Opinion and Order and Final Judgment 2009-06-03; Amended Final Judgment 2009-07-14), followed by Fenner's notice of appeal to the Federal Circuit on 2009-07-15.
• Link: http://www.bannerwitcoff.com/patentarcade/docs/FennerMicrosoftNoticeofAppeal.pdf
• Caveat: I did not verify the Federal Circuit docket number or disposition of that appeal from the sources retrieved; do not treat the appeal outcome as confirmed.

N.D. Cal. 3:05-cv-01987

• Google Patents' structured docket link lists a case in the Northern District of California for this patent (https://portal.unifiedpatents.com/litigation/California%20Northern%20District%20Court/case/3%3A05-cv-01987). I could not verify the parties or outcome from the sources retrieved; treat it as an unverified parallel-case pointer only. Note the Google Patents link is hosted by Unified Patents' litigation data portal — that is a data hosting relationship, not evidence that Unified Patents filed an AIA trial (it did not).

Strategic summary

Claim status: nothing canceled, everything untested except claim 1's scope. Because there was never an IPR, PGR, or CBM, no claim of 5,561,706 has been canceled or confirmed by the PTAB — there is no certificate under § 318(b). The only claim ever actually litigated is claim 1, and it was adjudicated only on non-infringement (claim construction + stipulated judgment), never on validity; Verizon's invalidity counterclaims were dismissed without prejudice. Claims 2–19 have never been construed or tested by any tribunal. That is an important asymmetry: the patent is not "hardened," but it is also not narrowed as a matter of Office record — its narrowness comes from a court's claim construction and from the prosecution disclaimer Fenner made in 1990s examination, now locked in by Fenner v. Cellco.

Estoppel landscape: zero. § 315(e)(2) estoppel attaches only to IPR/PGR petitioners and their privies/real parties in interest. With no AIA trial, no defendant anywhere is estopped from raising any prior-art ground — § 102, § 103, or § 112 (the latter only in district court; § 112 is outside IPR's statutory scope under §§ 311(b)/(a)). If you are defending a demand today, your full prior-art menu is open, including the Hayes reference (U.S. 5,210,787) that Fenner distinguished during prosecution by disclaiming device-centric systems, and the 18 references cited on the face of the patent. There is also no § 315(b) one-year clock running against you unless you have been served with a complaint — and even then, filing an IPR on a patent that expired 2013-10-01 buys you almost nothing strategically.

Pattern signals. Fenner Investments, Ltd. was a serial, small-entity-style assertion campaign against carriers and equipment vendors (Cisco, Juniper, Nokia, Nortel, Ericsson, Alcatel, Microsoft, Nintendo, Verizon, MetroPCS) across roughly 2005–2013. It lost the two decisions that mattered: the 2009 Microsoft/Nintendo rulings and the 2013 Verizon construction affirmed in 2015. Notably, Fenner never filed at the PTAB and never faced a petitioner there — most plausibly because (a) the patent was due to expire 2013-10-01, (b) IPRs only became available 2012-09-16, more than six years into the campaign and months before the Verizon judgment, and (c) CBM was a poor fit: this is a telecommunications call-routing/billing-architecture patent, not a "financial product or service" patent, and would likely have failed the CBM "technological invention" exclusion at 37 C.F.R. § 42.301(b). No defensive aggregator appears in the chain; Unified Patents appears only as host of the litigation-data link. The patent was assigned to Fenner Investments, Ltd. on 2000-10-10 (recorded 2000-10-27, Reel/Frame 011213/0876) and has been expired since 2013-10-01.

Recommended next steps

1. Lead with expiry, not with IPR. The patent's anticipated expiration is 2013-10-01 (status "Expired - Lifetime" in the structured data). Any demand premised on ongoing or post-2013-10-01 use of a PCS/cellular billing architecture is facially meritless. Only pre-expiration conduct within the § 286 six-year damages lookback can even theoretically be at issue — and § 286 caps recovery to six years before the complaint was filed.
2. If claim 1 is asserted, close with Fenner v. Cellco. Quote the operative construction — "personal identification number" means "a number separate from a billing code … identifying an individual system user, which is associated with the individual and not the device" — and the CAFC's affirmance at 778 F.3d 1320. Any accused system in which the identifier is tied to a device/SIM/line rather than the human user falls outside claim 1 as a matter of law. (Note: that 2015 opinion came from the district court, not the PTAB — link the CAFC PDF, not a PTAB FWD, since no FWD exists.)
3. Treat claims 2–19 as untested and plan accordingly. They are expired but never construed. If a demand letter asserts a dependent claim, there is no controlling claim construction and no Office validity ruling. Your cheapest path is § 102/§ 103 invalidity on the face-of-patent references plus the Fenner specification/prosecution-history disclaimer, which should apply with equal or greater force to the narrower dependent claims (claim 2's arithmetic-compression limitation, for instance, is expressly described in the specification with reference to then-co-pending application 07/737,147, now U.S. Pat. No. 5,498,258 — check that patent's prosecution history for admissions).
4. Verify independently before relying. If you need belt-and-suspenders confirmation of the zero-trial finding, pull PTAB E2E (https://ptacts.uspto.gov) and the USPTO Patent Center file wrapper for 07/952,998 for any post-grant paper, and confirm the absence of a reexamination control number. My search found none, but the structured ODP block is the canonical list and it is empty.
5. Do not over-read the absence of PTAB activity. Normally, a well-asserted patent attracting a multi-year campaign eventually draws an IPR — the absence here is explained by expiry and by Fenner's court losses, not by the patent being unassailable. Do not tell a client the patent is "PTAB-validated"; it has never been examined adversarially by the Board at all.

I'll verify the assignment record against USPTO Assignment Center and cross-reference the assignee against NPE directories.

Let me pull the assignment abstract and cross-reference the assignee against NPE directories.

Assignment & Ownership Reconstruction — US 5,561,706

Sourcing note: The patent-text legal-events block supplied with this analysis is authoritative for the reel/frame and conveyance data below. I attempted to reach the USPTO Assignment Center record (https://assignmentcenter.uspto.gov/) for the correspondent-of-record field; the search environment returned no Assignment Center page for application 07/952,998. The correspondent who filed reel 011213/0876 could not be recovered, and I am not going to guess it. That is the single largest gap in this report and is flagged where it matters.

Inventors

Peter R. Fenner — sole named inventor (filing 1992-09-29; no co-inventors appear anywhere on the face of US 5,561,706).

Employer at time of filing: not determinable, and the record affirmatively points away from a corporate employer.

• The application was filed by an individual, and the original assignee field reads "Individual" — not an employer. There is no recorded pre-issuance assignment to any company, which is the normal signature of an employer-owned invention under an employment agreement. Nothing was assigned until 2000, eight years post-issuance (see timeline below).
• Circumstantial context only (do not treat as employer evidence): the § 102/§ 103 prior-art and non-patent citations on this patent include M. Milenkovic, Working-Set Coprocessor, Technical Report 89-CSE-8, Dept. of Computer Science and Engineering, SMU, Dallas, TX (Mar. 1989), and Wittem et al., Arithmetic Coding for Data Compression, Comm. ACM (June 1987). Fenner's own related academic paper, An adaptive computer communications network designed with decentralized control, is indexed on IEEE Xplore.
• Separately, in the Fenner v. Juniper Networks complaint concerning the related U.S. 5,842,224 patent, Fenner pleads that the invention arose from his work "in satisfying the 1989 SBIR Program Topic Number N89-037 for the United States Navy," disclosed in a submission titled "An addressing technique for U.S. Navy traffic in a multimedia environment." That is SBIR-funded independent-inventor work, not corporate R&D — but note the pleading is tied to the '224 patent, not to the '706 patent. I am not importing it onto '706 as a fact; it is pattern evidence only.

Unusual-pattern check: The classic warning sign (all inventors departing the original assignee within 12 months of filing, preceding a portfolio fire-sale) does not apply — there is a single inventor, and there was no original corporate assignee to depart from. Instead the salient pattern is the inverse: an individual held the patent personally for ~8 years post-issue before moving it into a family-owned licensing entity.

Original assignee

Peter R. Fenner, as an individual ("Individual" on the issued patent record). Fenner, Peter R. is also the assignor of record on the sole post-issuance assignment.

• Did they ship a product embodying the claims? No evidence of any product. The '706 patent claims a network architecture and method (multiple PCS switches, billing authorities, location authorities, service profiles) — a carrier-network-level system, not a device. An individual inventor could not have deployed it. To my knowledge there is no commercial embodiment.
• Primary line of business: Independent invention / R&D contracting (SBIR work for the U.S. Navy per the related '224 pleading). Not an operating company.
• Current status: The individual assignor is the natural-person principal behind the assignee entity; no bankruptcy, dissolution, or acquisition is recorded for the original assignee (a natural person cannot be "dissolved").

Assignment timeline

The Assignment Center / Google Patents legal-events record for US 5,561,706 contains exactly one post-issuance assignment. There is no cascading chain. The complete recorded chain is:

[1] 2000-10-10 (executed) / recorded 2000-10-27 — Reel 011213/0876

• Conveyance: Assignment — "ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)" (Google Patents legal-events code AS)
• Assignor: Fenner, Peter R.
• Assignee: Fenner Investments, Ltd. (Texas; address of record per D&B: 600 Goodwin Dr., Richardson, TX 75081)
• Correspondent: ⚠️ Not recovered. The legal-events record exposes the reel/frame and the assignment description but not the recording correspondent. I searched for the correspondent of record and did not obtain it; I decline to name an attorney on inference. Verify at Assignment Center (https://assignmentcenter.uspto.gov/, search application 07/952,998 or reel 011213/0876).
• Context: transfer-to-asserter — the sole inventor moved the patent into a family-owned licensing entity ~4 years before the first '706 infringement suit and ~8 years after grant.

Every other legal event on this patent is not an assignment:

No security agreement, no merger, no change of name, no license, no release, and no second assignment was ever recorded.

Timeline diagram

timeline
    title Ownership of US 5561706
    1992 : Filed by Peter R Fenner as individual
    1996 : Patent issued to Fenner as individual
    2000 : Assigned to Fenner Investments Ltd
         : Reel 011213 frame 0876
    2005 : First infringement suit filed E D Tex
    2011 : Suit vs Verizon and MetroPCS
    2013 : Patent expires
    2015 : CAFC affirms noninfringement

NPE / troll-pattern signals

1. Shell-entity transfer — present (with a caveat)

The patent moved from the individual inventor to Fenner Investments, Ltd., a Texas entity whose registered business profile (Dun & Bradstreet) lists industry "Patent Buying, Licensing, Leasing," estimated annual revenue $68,000, employee count 1, with Peter Fenner as the contact. That is textbook licensing-only, no-products, single-principal structure. The caveat that keeps this from being a classic third-party shell: the complaint in Fenner v. Juniper states plainly that "Fenner is wholly owned by members of the Fenner family" and that "Peter R. Fenner is the sole inventor" of the asserted patent, with the patent "assigned to Fenner Investments, Ltd." So this is the inventor's own monetization vehicle, not an arm's-length transfer to a stranger shell. Reel 011213/0876; executed 2000-10-10 / recorded 2000-10-27.

⚠️ Entity-age discrepancy to resolve: D&B lists the entity as founded 2001, and Patsnap lists 2009, yet the assignment was recorded 2000-10-27. These cannot all be right. Third-party company-profile "founded" dates are frequently stale or wrong; the recorded assignment date is the reliable one.

2. Known asserter in the chain — present

Fenner Investments, Ltd. is expressly classified as a patent monetizer in the literature: the academic compilation "US Patents in Classes 379 and/or 455 Asserted in Patent Litigations filed in 2011–2012 by Apparent Patent Monetizers and Operating Companies" lists US 5,561,706 … 1 litigation … Owner: Fenner Investments, Ltd. German tech press (heise) describes Fenner Investments Ltd. as a "texanischer Patentverwerter" (patent monetizer).

It is not, however, on any of the enumerated public NPE lists you supplied (Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, Spangenberg entities). It is a small, family-run asserter, not a large aggregator. Asserted patents in the campaign include the '706 patent, U.S. 6,819,670, U.S. 5,842,224, U.S. 6,297,751 (the joystick patent used against Microsoft/Nintendo), and the packet-switching-node family (U.S. 5,095,480 / 7,145,906).

3. Repeat correspondent across the chain — unclear (data gap)

There is only one assignment link, so "recurrence across the chain" is structurally impossible to establish here. I could not retrieve the recording correspondent for reel 011213/0876 — that field is not exposed by the sources available to me, and naming one would be fabrication.

A related but distinct recurrence that is documented: the same litigation counsel appear across the Fenner campaign — Franklin Jones, Jr. and Jack Wesley Hill are listed as plaintiff's attorneys in Fenner v. 3Com, No. 6:08-cv-00061 (E.D. Tex.), and in the earlier Fenner suits. That is plaintiff-side litigation counsel, not the assignment-recording correspondent, and I flag it as such rather than conflating the two.

4. Cascading transfers — not present

One recorded assignment across a 24-year life (1992 filing → 2013 expiration). No chained LLCs, no sub-24-month sequence, no shared correspondent addresses to analyze.

5. Pre-litigation transfer — not present

The assignment executed 2000-10-10; the first '706 suit (Fenner v. Juniper Networks, No. 2:05-cv-00005, E.D. Tex.) was filed 2005-01-06 — a gap of roughly four years and three months, well outside the six-month window. The transfer was made with a long runway, not on the courthouse steps. (The later Fenner v. Cellco/Verizon suit, No. 6:11-cv-00348, filed 2011-07-06, is even further out.)

6. Bankruptcy fire-sale — not present

No Chapter 7/11 proceeding, no liquidating trust, no court-supervised sale appears in the chain. The single transfer was a private, family-internal conveyance.

7. Privateering — not present

Privateering requires an operating company upstream supplying products and/or funding to an NPE that asserts on its behalf. Here the upstream is a natural-person independent inventor who never practiced the invention. There is no operating-company benefactor, and no SEC filing of the kind that typically surfaces privateering arrangements is implicated.

8. Defensive aggregator — not present

The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates with the expired patent still held by the family entity. (Note for the record: the Google Patents litigation link to a Unified Patents hosting URL is a data-hosting relationship, not evidence of Unified involvement — consistent with the prior section's finding of zero AIA trials.)

Verdict

NPE — high confidence.

Justification (two strong signals, not inference from naming):

1. Shell/ licensing-only transfer (reel 011213/0876, executed 2000-10-10, recorded 2000-10-27): the patent left the individual inventor for Fenner Investments, Ltd., a Texas entity whose business profile is "Patent Buying, Licensing, Leasing," ~$68,000 revenue, and one employee — with no product and no evidence of any commercial embodiment of a carrier-network architecture claim set.
2. Known asserter: Fenner Investments, Ltd. is independently classified as an "apparent patent monetizer" in the patent-litigation literature and as a patent monetizer in the trade press, and it ran a multi-year, multi-defendant assertion campaign (Cisco, Juniper, Nokia, Nortel, Ericsson, Alcatel, then Verizon and MetroPCS) in which the '706 patent was one of several unrelated asserted patents.

Important qualification — this is an inventor-controlled NPE, not a classic aggregator. The record shows Fenner is "wholly owned by members of the Fenner family" and that Peter R. Fenner is the sole inventor, so signals 5 (pre-litigation transfer), 6 (bankruptcy fire-sale), and 7 (privateering) are all absent, and the assignment chain is a single link rather than a cascade. Do not describe this as a portfolio flipped by a third-party troll; it is self-monetization by the inventor's own family entity, which is a materially weaker troll profile — and it is moot in any event because the patent expired 2013-10-01.

Verification link (Assignment Center): https://assignmentcenter.uspto.gov/ — search by patent number 5561706 or by reel/frame 011213/0876. Companion index: https://assignment.uspto.gov/patent/index.html

Open items I could not close from this environment: (a) the correspondent of record for reel 011213/0876; (b) the entity-formation date of Fenner Investments, Ltd. (D&B 2001 vs. Patsnap 2009 vs. the 2000 recording). Both are single-lookup items against the Assignment Center and Texas Secretary of State records respectively.

I'll verify the key cited references against public databases before doing the § 102 mapping.

Let me verify two more key references — the pointer-compression reference and the Ericsson subscription-supervision reference.

Prior-Art Analysis — U.S. Patent No. 5,561,706

Cross-reference note: This section builds on the previously generated Patent Summary, Litigation Summary, and PTAB sections. It does not repeat the bibliographic table, the claim-by-claim overview, or the Fenner v. Cellco litigation/prosecution-disclaimer discussion — but it does rely on that disclaimer, because it is dispositive of the § 102 picture below. If you need those, see the earlier sections.

0. Source and scope confirmation

The task asks me to search for 5561706 specifically. I confirmed the identity against the authoritative Google Patents record and independent lookups: US 5,561,706, Application No. 07/952,998, filed/priority 1992-09-29, granted 1996-10-01, inventor Peter R. Fenner, now Fenner Investments, Ltd. I did not substitute any similar number (e.g., the related Fenner patent 5,498,258, the '670 patent 6,819,670, or the packet-switching family member 5,095,480 are different patents and are treated as such below).

The universe of "patent citations for 5561706" is the 18 U.S. patent references and 14 non-patent citations listed on the face of the '706 patent (they appear in the furnished record under "Patent Citations (18)" and "Non-Patent Citations (14)"). Everything below is drawn from that face-of-patent list plus my verification searches.

1. The § 102 framework that governs (this matters)

Because the '706 patent was filed 1992-09-29 — long before the AIA's 2013 first-to-file change — pre-AIA 35 U.S.C. § 102 applies. The mechanics that decide whether each cited reference is even available as prior art:

Two consequences worth stating up front:

1. Several cited patents did not publish until after the '706 filing date (1993–1994). They are still prior art, but only as § 102(e) art, effective as of their U.S. filing dates — which are all earlier than 1992-09-29.
2. Anticipation (§ 102) requires a single reference to disclose every limitation of a claim, arranged as claimed. The fact that these references were cited and the patent still issued strongly suggests the examiner found no single-reference anticipation. My "potential § 102" mappings below must therefore be read as arguable anticipation, with the missing element identified.

2. The 18 patent citations mapped to the '706 claims

Filing/publication dates are from the face of the '706 patent. "§ 102 hook" = the subsection under which the reference is available; "claims" = the claims whose limitations it arguably reaches (usually as § 102(e)/(a) art, frequently better characterized as § 103 fodder).

2A. Highest-relevance references

① US 5,210,787 — Hayes/Ericsson, "Subscriber interrogation point" (the reference Fenner distinguished during prosecution)

• Filed 1991-02-05; granted 1993-05-11; Telefonaktiebolaget LM Ericsson.
• § 102 hook: § 102(e) (as of 1991-02-05).
• Disclosure (verified): A cellular network in which each exchange stores the identity of a subscriber interrogation point (SIP) associated with a mobile subscriber's mobile identification number (MIN); a visited exchange sends a location update request, the SIP forwards it to the home location of the visiting subscriber, and the home exchange returns preselected information including "the service parameters of said mobile" (US5210787 claim 9). The visited exchange stores the returned information.
• Potentially anticipates: the location-tracking and remote profile retrieval limitations of claims 1, 4, 5, 6, 12, 13, 14, 15, 18 — i.e., a switch that (i) receives a subscriber identifier, (ii) queries an authority that tracks location, and (iii) retrieves subscriber service parameters.
• Where it falls short of full anticipation: Hayes keys everything to the MIN tied to the mobile station, and there is no user-entered billing code selecting among a plurality of billing authorities. That gap is exactly why Fenner argued Hayes was "device-centered." Under the CAFC's Fenner v. Cellco construction, claim 1 requires the identifier to be user-associated and a billing code separate from it — so Hayes does not anticipate claim 1, but it is powerful § 103 art against the location/profile architecture, and it is the § 102/§ 103 centerpiece for any defendant.

② US 4,899,373 — AT&T Bell Labs, "Method and apparatus for providing personalized telephone subscriber features at remote locations"

• Filed 1986-11-28; granted 1990-02-06.
• § 102 hook: § 102(b) (published 1990-02-06, more than one year before filing).
• Disclosure: Provides a subscriber's personalized telephone features at a remote switch by identifying the subscriber and retrieving/loading the subscriber's feature profile at the location where the subscriber is present.
• Potentially anticipates: the profile-retrieval-by-user-identity and switch-stores-profile-before-granting-access limitations of claims 1, 9, 15 (and, arguably, 3/11's profile-storage concept).
• Shortfall: wireline context; no RF switch, no plurality of billing authorities, and no user-supplied billing code. A § 102(a)/(b) reference for the "personalized profile fetched to the serving switch" concept, but not a full anticipant of any independent claim.

③ US 5,276,868 — Digital Equipment Corp., "Method and apparatus for pointer compression in structured databases"

• Filed 1990-05-23; granted 1994-01-04.
• § 102 hook: § 102(e) (as of 1990-05-23).
• Disclosure (verified): Reduces storage in TRIE-structured databases by eliminating NIL pointers and, critically, performs a logical-to-physical index translation so that a search key is converted into an index that addresses a stored record element (via a bit-mask/translation matrix or a look-up table).
• Potentially anticipates: the arithmetic-compression/integer-index limitation of claims 2, 10, 12, and 15 ("arithmetically compressing the personal identification number to unique integer index value … the integer value pointing to a location in the database storing the service profile").
• Shortfall / nuance: DEC's technique is pointer compression (removing NIL pointers), not arithmetic compression (Witten coding). But the claimed result — a key converted to an index that points into a record table — is squarely the subject of this reference. Treat it as the strongest structural § 102(e)/§ 103 reference against the index-table claims.

④ US 5,148,472 — Freese, "Cellular telephone call administration system"

• Filed 1990-12-05; granted 1992-09-15 (verified; assignee Subscriber Computing, Inc.).
• § 102 hook: § 102(e) (as of 1990-12-05). (Published only 14 days before the '706 filing, so it is not § 102(b) art.)
• Disclosure (verified): Monitors all call records at a cellular switch as calls are processed; classifies records into service classes/divisions, rates certain classes, and distributes call detail records to multiple billing facilities (reseller routers, roam clearing house, billing service providers); supports roam registration without a billing agreement with the home carrier and credit-card authorization of roaming charges.
• Potentially anticipates: the billing-authority and service-class/profile aspects of claims 1, 15, 16 (multiple billing/service relationships per subscriber).
• Shortfall: the classification is performed by the carrier's switch/system, not by a user-entered billing code designating one of a plurality of billing authorities. No RF-switch-requested service profile keyed to a user-selected billing authority.

⑤ US 4,955,049 — Ericsson, "Method of supervising mobile telephone subscriptions in a mobile telephone system"

• Filed 1989-08-11; granted 1990-09-04.
• § 102 hook: § 102(b).
• Disclosure (verified): Fraud detection by call-number sequencing — checking that each subscriber's call numbers occur once, in sequence, consistent with time-of-day, against a responsible database such as the home MSC (HMSC) or an authentication center (AC).
• Potentially anticipates: the fraud-detection / check-out functionality described in the '706 specification (fraud protection means 7 and 14) — but none of claims 1–19 expressly recites fraud detection, so this reference is background/§ 112 enablement art and § 103 support, not a § 102 anticipant of a claim.

⑥ US 5,247,698 — Ericsson, "Use of an audit message sent to mobile stations to confirm the location thereof"

• Filed 1990-02-26; granted 1993-09-21.
• § 102 hook: § 102(e) (as of 1990-02-26).
• Disclosure: Confirming a mobile station's location via an audit/verification message exchange with the network.
• Potentially anticipates: the location-tracking-authority limitation in claims 1, 4, 13, 18.
• Shortfall: device-location confirmation only; no billing authority, no service profile, no user billing code.

⑦ US 5,303,286 — Space Systems/Loral, "Wireless telephone/satellite roaming system"

• Filed 1991-03-29; granted 1994-04-12.
• § 102 hook: § 102(e) (as of 1991-03-29).
• Disclosure: A wireless/satellite roaming architecture with home and visited registry databases tracking subscriber location and authorizing service.
• Potentially anticipates: the roaming / location-authority / home-assignment limitations of claims 1, 4, 5, 15, 17, 18.
• Shortfall: registry keyed to subscriber/mobile identity and to the network's own assignment; no user-selected billing authority.

⑧ US 5,260,987 — Northern Telecom, "Mobile communications"

• Filed 1990-06-18; granted 1993-11-09.
• § 102 hook: § 102(e) (as of 1990-06-18).
• Disclosure: Mobile-communications roaming/location management.
• Potentially anticipates: location/roaming limitations of claims 1, 4, 13, 18. Same shortfall (no billing-authority-selection element).

⑨ Witten et al. (non-patent) & ⑩ Milenkovic (non-patent) — see § 3 below; both are directly on point for specific limitations.

2B. Lower-relevance references (still on the face of the patent)

(All under § 102(a)/(e) availability notwithstanding publication after 1992-09-29, since each U.S. filing date precedes the '706 filing date.)

3. The non-patent citations (printed publications)

Because each was published before 1991-09-29, every one is § 102(b) art — the most robust category.

Note: I have high confidence in the dates and categories of these non-patent references (they are printed on the face of the patent), and in the subject-matter relevance of Witten and Milenkovic. I have not independently pulled the full text of the IEEE PCS articles to confirm their precise disclosures; treat their claim-mapping as a relevance indication, not a verified anticipation.

4. Bottom line — "most relevant" ranking and § 102 verdict

Ranked most → least relevant to the claims:

1. US 5,210,787 (Hayes/Ericsson, subscriber interrogation point) — closest to the location-authority + remote-service-profile architecture of claims 1/15/18; the very reference Fenner distinguished.
2. US 4,899,373 (AT&T, personalized features at remote locations) — § 102(b); the "fetch the user's profile to the serving switch" concept.
3. US 5,276,868 (DEC, pointer compression) — § 102(e); the key→index→record limitation of claims 2/10/12/15.
4. Witten et al. (1987) — § 102(b); the arithmetic compression limitation itself.
5. US 5,148,472 (Freese, cellular call administration) — § 102(e); multiple billing relationships / service classes per subscriber (claims 1/15/16).
6. US 5,303,286 / US 5,247,698 / US 5,260,987 — location/roaming-registry art for claims 4/5/13/18.
7. US 4,955,049 / US 5,335,278 — fraud-detection background (spec, not claims).
8. Milenkovic (1989) — LRU/working-set art for claims 3/11.
9. Remaining references (Oki 4,845,740; Motorola 4,860,341; AT&T 5,206,899 & 5,282,244; IBM 5,247,520; Sony 5,255,307; Ericsson GE 5,241,598; Ram Mobile Data 5,341,410) — peripheral; no single-reference anticipation of any independent claim.

Critical § 102 conclusion: No single cited reference anticipates independent claims 1, 10, 15, or 18. The reason is the claim element no reference supplies: the billing code received from the user that designates one of a plurality of billing authorities (claim 1; mirrored in claim 15's "billing authority designator received from the user"). The closest references (Hayes, AT&T '373, Freese) retrieve a profile/location based on a system- or device-held identifier, not a user-entered billing-authority selector. Consistent with this, the examiner issued the patent over all 18 references without a § 102 rejection that stuck.

Where the references bite hardest is § 103, not § 102. Hayes + AT&T '373 + Freese together teach the switch-queryable location/profile architecture and multiple billing relationships; Witten and DEC '868 teach the index/compression limitation; Milenkovic teaches the LRU overwrite. A § 103 combination along those lines is the realistic invalidity theory — and, per the earlier Litigation and PTAB sections, no court or the PTAB ever adjudicated validity of any claim, so that theory remains fully open (Verizon's invalidity counterclaims were dismissed without prejudice).

5. Caveats (stated plainly)

• Status of these references: All 18 were considered by the examiner (they appear as "Cited by examiner"), and the patent issued. A "potential § 102" mapping is not a finding of invalidity — it identifies which claims each reference could arguably reach if a petitioner/defendant built the record.
• § 102(e) "by another" limit: For US 5,095,480, the reference shares the same inventor (Fenner), so it is not § 102(e) art; I did not treat it as anticipating.
• Invention-date dependency: Two references were filed in 1992, only months before the '706 filing — US 5,255,307 (filed 1992-05-07) and US 5,341,410 (filed 1992-07-21). Their § 102(e)/(a) availability depends on the '706's actual invention date; absent a Rule 131 record, the filing date (1992-09-29) controls and both qualify.
• Verification depth: I verified the disclosures of Hayes (US 5,210,787), Freese (US 5,148,472), DEC (US 5,276,868), and Ericsson (US 4,955,049) against independent full-text/abstract sources. For the remaining references I relied on the face-of-patent listing plus title-level subject matter; I did not pull each full specification, so their claim-by-claim mapping should be confirmed against the actual documents before being used in a filing.
• No live USPTO PatentCenter/PTAB-E2E query was made from this environment; the citation list is taken from the authoritative Google Patents record for US5561706A furnished with this task, which reproduces the front-page citations.

Would you like me to build a § 103 combination chart (Hayes as primary reference + AT&T '373 / Freese / DEC '868 as secondary) mapped against independent claims 1, 10, 15, and 18, or to pull the full text of any specific reference to firm up the anticipation mapping?

I'll ground this § 103 analysis against the actual prior-art references listed on the patent's face, then map them claim-by-claim.

Let me pull the remaining key references — the location-tracking, roaming, credit-card-call, and database-indexing art.

Obviousness Analysis — U.S. Patent No. 5,561,706 under 35 U.S.C. § 103

Sourcing note. This analysis uses (a) the full claim set, specification, and the face-of-patent prior-art list you supplied from the Google Patents record for US5561706A, and (b) targeted web verification of the disclosures of the four references most likely to carry an obviousness case (Lee US 4,899,373; Freese US 5,148,472; Hayes US 5,210,787; Ericsson US 4,955,049; and Northern Telecom US 5,260,987). I hit the tool-step ceiling before I could pull full text for US 5,341,410, US 5,276,868, US 5,335,278, US 5,303,286, US 4,845,740, US 4,860,341, US 5,206,899, US 5,282,244, US 5,247,520, US 5,255,307, and US 5,241,598. For those I rely on the titles, dates, assignees, and classification data printed on the '706 face, and I say so where the gap matters. No contradiction with the earlier-generated sections was found — the Hayes/serial-number, expiry, and claim-1-scope findings all check out against this pass.

1. Legal framework applied

Because application 07/952,998 was filed September 29, 1992, pre-AIA § 103 governs, though the Graham v. John Deere, 383 U.S. 1 (1966) factors and the KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) rationales supply the operative test:

1. Scope and content of the prior art;
2. Differences between the prior art and the claims;
3. Level of ordinary skill in the pertinent art;
4. Secondary considerations (nexus required).

Under MPEP § 2143, a rejection needs an articulated reason to modify/combine, drawn from: (A) combining prior art elements per known methods to yield predictable results; (B) simple substitution of one known element for another; (C) use of a known technique to improve a similar device in the same way; (D) applying a known technique to a known device ready for improvement; (E) "obvious to try"; (F) design incentives and market forces; (G) teachings, suggestions, or motivations in the references themselves.

Critical overlay from the prior sections — do not lose this. The single most important constraint on any § 103 theory here is the construction that Fenner Invs., Ltd. v. Cellco P'ship, 778 F.3d 1320 (Fed. Cir. 2015) affirmed: "personal identification number" means "a number separate from a billing code . . . identifying an individual system user, which is associated with the individual and not the device." Any obviousness combination must therefore place in the prior art a user-anchored (not device-anchored) identity — or must argue that a reference's device-anchored identity nonetheless satisfies the construction. This is where the strongest attacks live and also where the case is most vulnerable, because Fenner disclaimed device-centric systems during prosecution. The disclaimer narrows the claim; it does not confer validity. It cuts both ways and I flag each instance below.

2. Level of ordinary skill in the pertinent art (Graham factor 3)

The '706 field is cellular/PCS call routing, wireless billing, and Intelligent Network (IN/SS7) database architecture. A POSITA at the September 1992 priority date would have had:

• a B.S. in electrical engineering or computer science (or equivalent) and 2–4 years of experience in stored-program-controlled telephone switching and/or cellular MSC design; or
• a master's degree and 1–2 years of such experience.

That person would have been familiar with, as of 1992: Home Location Registers (HLRs) and Visitor Location Registers (VLRs); SS7 signaling and Service Control Points (SCPs); roaming agreements and inter-carrier settlement (CIBER clearing houses); credit-card call validation at a switching office (TSPS/operator services); and standard database/cache design (LRU replacement, hash/index tables, pointer compression). The applicant's own background section concedes the prior art was telephone-centric; that concession frames the "differences" analysis below.

3. Scope and content of the prior art (Graham factors 1–2)

All eighteen U.S. references and all non-patent items were cited by the examiner and predate the September 29, 1992 filing date. The five IEEE Communications Magazine items (Dec. 1988 and Feb. 1991), Witten, and Milenkovic all pre-date September 29, 1991 and are therefore § 102(b) printed publications. US 4,899,373 (filed 1986-11-28), US 5,148,472 (filed 1990-12-05), US 5,210,787 (filed 1991-02-05), and US 5,276,868 (filed 1990-05-23) pre-date the '706 filing date and are § 102(e) prior art as well.

3.1 Reference-by-element map

4. Independent claims — proposed combinations and motivation to combine

Claim 1 (user PIN + user-entered billing code designating one of plural billing authorities)

Primary combination: US 4,899,373 (Lee) + US 5,210,787 (Hayes) + US 5,148,472 (Freese).

Motivation (KSR rationales A, C, F). All three references are in the same field (stored-program telephone switching), address the same problem (delivering a subscriber's personalized service set at a location away from home), and were known to be combinable — Lee itself cites the pay-phone/card-reader environment; Hayes was developed expressly to simplify maintenance of subscriber information across MSCs; Freese exists to rate and bill roamers and resellers. Deploying PCS required (i) user-anchored identities (Lee), (ii) a location registry to find roaming users (Hayes), and (iii) a billing infrastructure that could bill someone for a roamer who has no home-carrier agreement (Freese). A POSITA facing the PCS rollout had a clear design incentive to bolt a card/billing-authority designation onto Lee's profile-retrieval flow and Hayes' registration flow. The "billing code" is the weakest element against this trio: the art shows the credential being entered, but not a separate code that selects among competing billing authorities.

Best single-reference-plus-template attack on the "billing code" element: combined with US 4,845,740 (Oki) and US 4,860,341 (Motorola) — radiotelephone systems reading a credit card and routing call approval/billing to the identified issuing entity. These were verified only by title/date on the '706 face (I could not pull full text), so this leg of the argument should be confirmed against the reference text before it is relied on.

Weakness / counterargument. The claim requires the billing code to be distinct from the PIN (lock-in from the Fenner construction, which construed "billing code" as "a code separate from the personal identification number"). Lee conflates the two (the credit-card number is the PIN). A patentee would argue that none of Lee, Hayes, or Freese teaches a two-credential logon. That is a genuine gap, though it is a narrowing argument, not a validity-conferring one — and the two-credential arrangement was itself conventional in calling-card telephony (calling card number + carrier-access/authorization code).

Claim 10 (PIN → arithmetic compression to unique integer index → profile stored at that index)

Primary combination: US 5,276,868 (DEC pointer compression) + Witten et al. (arithmetic coding) + Lee '373.

Motivation (rationales B, C, D). Claim 10 is the whole invention of claim 15 minus the logon plumbing, plus one data-structure step. Mapping a numeric identifier to a compact integer index is the plain purpose of US 5,276,868. Witten teaches arithmetic coding (a lossless, reversible mapping of a symbol string to a compressed representation) in the same pre-1991 window. Putting a compressed identifier to work as a record pointer in a subscriber database — exactly the "known technique to improve a similar device in the same way" rationale (C) — is the kind of predictable, mechanical improvement KSR holds obvious. Notably, the '706 specification itself sources this limitation out: it states the "apparatus and method for arithmetic compression and service profile storage can be similar to that described in co-pending application serial No. 07/737,147 now Pat. No. 5,498,258." That is an admission that the compression/indexing technique was not the applicant's contribution.

Secondary point. Arithmetically compressing a fixed-length digit string to a unique integer is, at the limit, nothing more than parsing the digits — a one-to-one mapping. A POSITA would not regard a "unique" (i.e., non-colliding) index as inventive.

Weakness. If the patentee reads "arithmetically compressing" narrowly (per Witten's probabilistic coder), a § 103 case needs the combination to expressly suggest using compression for indexing, not merely for transmission. US 5,276,868's pointer-compression disclosure is the piece that closes that gap, and I could not pull its full text in this pass — verify before relying.

Claim 15 (local switch searches its profile database by compressed ID; if absent, requests profile from the user-designated billing authority and location from the user-designated location authority; logs on when both return)

Primary combination: US 5,210,787 (Hayes) + US 5,148,472 (Freese) + US 5,276,868/Witten.

This is the claim most exposed. Hayes discloses, step for step:

• a visited exchange receiving a subscriber identity and searching its memory for stored subscriber data;
• if absent, requesting the subscriber's data from a home location identified by the subscriber's mobile identification number (the digit analysis table stores, per MIN, the identity of the SIP to query — i.e., the MIN is the "location authority designator received from the user," as in claims 4/13);
• storing the returned service parameters in the visited exchange (Hayes claim 10); and
• a separate location-routing node (the SIP) distinct from the node holding service parameters (the home exchange/HLR) — i.e., the '706's location-authority/billing-authority split.

Freese adds the billing authority dimension: multiple resellers and service classes, with credit-card authorization for roamers who lack a home-carrier agreement — the commercial "who pays" question that would motivate separating the billing authority from the location authority. Head (Dec. 1988) supplies the architectural roadmap (distributed IN databases queried by switches) that makes the separation an expected design choice.

Motivation (rationales A, C, D, F). Hayes' entire premise is that scattering subscriber data across every MSC is a "huge undertaking"; moving routing identity to SIPs and service parameters to home exchanges is the reference's own suggestion (motivation in the reference, rationale G). Once that split exists, making the user designate which of several entities maintains the profile and which maintains the location is the predictable consequence of a multi-operator PCS market (rationale F). The log-on gate "not until both the profile and location are received" is the ordinary safety sequencing a POSITA would impose on a two-database lookup.

Claim 18 (call completion: local-check first; else identify the destination's location tracking authority, request the destination switch identity, receive it, route)

Primary combination: US 5,210,787 (Hayes) + US 5,260,987 (Northern Telecom) ± US 5,341,410.

This claim is essentially the terminating-call half of Hayes' and Northern Telecom's disclosure. Hayes: "Data related to the service of each mobile subscriber and the last known geographic location of the subscriber is stored in memory in a home location associated with each mobile subscriber"; a location update request returns the visited exchange address — the "identity for a destination communication switch on which the destination user is currently logged onto." Northern Telecom '987 discloses HLR/VLR registers "used to locate and track subscribers." US 5,341,410 (whose full text I could not retrieve) is titled as a cellular telephone locator and, per its title, targets locating a mobile subscriber — verify.

Motivation. Call delivery to a mobile is precisely the problem these references were built to solve; the local-check-first optimization is ordinary routing economy (avoid a database query when the destination is already registered locally). Rationale A/C, plus the express motivations in Hayes.

Weakest element. Claims 18–19's insistence that the identification code be device-independent across the whole network meets the Fenner disclaimer head-on. Here the NPL PCS articles are the best answer: the Feb. 1991 IEEE Communications Magazine pieces (Ginn, "Personal Communications Services: Expanding the Freedom to Communicate"; Singer/Irwin; Ross, "Wireless Network Directions"; Lynch, "PCN: Son of Cellular?") describe the PCS vision of a number that follows the person rather than the terminal — published more than eighteen months before the '706 filing date.

5. Dependent claims — predicted disposition

Net: claims 4, 9, 13, and 6/12 are the cleanest § 103 hits; claims 1, 10, and 15 are strong but each has a single soft element (the two-credential billing code; the "arithmetic" character of the compression; the forced-log-off in claim 17); claims 16, 17, and 19 are the residual battleground.

6. Secondary considerations (Graham factor 4)

I found no evidence in the record of nexus-bearing objective evidence:

• No unexpected results: the specification asserts no comparative data against Lee, Hayes, or Freese. The claimed advantages (user-based billing, capacity-efficient profile storage) are the expected consequences of user-keyed profiles plus cache management.
• No commercial-success nexus: PCS and cellular roaming succeeded industry-wide, and no showing ties that success to the '706's specific two-authority + billing-code architecture rather than to competitive and regulatory forces.
• Long-felt need cuts both ways: the need to control cellular fraud and roaming cost was real (see US 5,148,472; US 4,955,049; US 5,335,278), but those references were addressing it — which supports obviousness, not nonobviousness.
• The patentee's own background section concedes that "few solutions have been presented" with respect to PCS management specifically, which frames the differences narrowly rather than broadly.

Given that the E.D. Tex., N.D. Cal., Microsoft/Nintendo, and Juniper actions all resolved without any adjudicated validity holding, there is no judicial or PTAB validation to counterbalance this analysis (consistent with the PTAB section above: zero AIA trials, no claim ever canceled or confirmed).

7. Assumptions, gaps, and what to verify before relying on this

1. The Fenner disclaimer is the swing factor. The user-anchored construction narrows claim 1 but does not immunize it. Conversely, if a defendant's art is device-anchored (Hayes' MIN-in-the-phone, Lee's station-associated feature data), the patentee will invoke the disclaimer to escape. Every combination above should be tested against that construction first.
2. Unverified reference texts. I retrieved and relied on the actual disclosures of US 4,899,373, US 5,148,472, US 5,210,787, US 4,955,049, and US 5,260,987. I did not retrieve full text for US 5,276,868, US 5,341,410, US 5,335,278, US 5,303,286, US 4,845,740, US 4,860,341, US 5,206,899, US 5,282,244, US 5,247,520, US 5,255,307, or US 5,241,598. The DEC pointer-compression reference (US 5,276,868) and the two credit-card radiotelephone references (US 4,845,740; US 4,860,341) are load-bearing for claims 2/10/12/15 and 1 respectively — pull those three first.
3. The prosecution history was only partly reconstructed. The earlier sections establish that Fenner distinguished US 5,210,787 (Hayes) during prosecution, which means the examiner applied Hayes against the claims. I do not have the file wrapper's exact rejections or the secondary references the examiner combined with Hayes. Obtaining the 07/952,998 file wrapper would materially sharpen this analysis — it would show which combinations the Office already rejected and which the applicant's arguments defeated.
4. Non-cited art was outside this task's scope. You asked for combinations drawn from the Prior Art section of this page. The strongest uncited art (e.g., the GSM/PCN standards work and the 1990–1991 ITU/Yankee Group PCS literature) is not analyzed here.
5. The claim-17 forced-log-off gap is the one limitation I could not close from the face-of-patent list. If a validity challenge needs claim 17, that limitation requires a separate search.
6. Date discrepancy, flagged: the surrounding system context is dated 2026-09-27 while this task states April 26, 2026. Nothing in the analysis is date-sensitive to that difference — the patent expired 2013-10-01 and the § 103 analysis is confined to the September 29, 1992 priority date — but I note it rather than silently reconciling it.

8. Bottom line

On the face-of-patent art, claims 4, 6, 9, 12, and 13 are the most clearly obvious, primarily over US 5,210,787 (Hayes) alone or in view of US 5,260,987 (Northern Telecom) and US 5,148,472 (Freese) — Hayes' subscriber interrogation point teaches the location-authority/billing-authority split, the MIN-keyed location lookup, and the request-and-store-the-service-parameters flow with unusual completeness. Claims 2, 3, 10, 11, and 15 are strongly obvious over US 5,276,868 (pointer compression) plus the Witten arithmetic-coding paper, with the '706 specification's own incorporation-by-similarity of app 07/737,147 operating as an admission. Claims 1, 8, and 16 are obvious over Lee '373 + Freese '472 + Hayes '787, with the residual softness concentrated in the claim-1 requirement that the billing code be separate from the PIN and select among billing authorities. Claims 7 and 19 are the moderate tier. Claim 17 is the outlier and the only claim for which I cannot construct a clean § 103 case from the cited art.