US 6169899

I'll search for authoritative information on this patent number, including any 2026 CAFC activity.

Let me run two more targeted searches to check for any litigation or 2026 court activity.

Search Scope and Caveats

I searched for the specific number 6169899 across Google Patents/PatentsView-style sources and general web indexes for USPTO and CAFC 2026 activity.

• I found no CAFC 2026 docket, appeal, IPR, or district-court case that names U.S. Patent 6,169,899. Ericsson-family 2026 litigation surfaced in my searches (e.g., Ericsson v. Acer, Ericsson v. Transsion, Ericsson v. Verifone, NovaCloud/Oracle matters), but none of it identifies the '899 patent. I cannot access PACER/Docket Alarm or the live CAFC docket docket-by-docket in this session, so I state this as "not found, not confirmed absent."
• Literal-identifier warning: a search for "6169899" also returns JP 6169899 B2, a Shiseido cosmetics patent (凹凸補正用化粧料, registered 2017). That is a different jurisdiction and unrelated subject matter and must not be conflated with US 6,169,899.
• The specification text below is drawn from the authoritative Google Patents full text of US6169899B1. Bibliographic fields I could not verify against a second independent USPTO source (e.g., Patent Center) are flagged.

Bibliographic Summary

Abstract (as issued)

A telecommunications system and method for providing location information consisting of either real-time data or historical data when the subscriber requested to be positioned is either absent or not reachable, to a requesting location application (LA). The historical data is preferably stored per subscriber in a database within a serving Mobile Switching Center/Visitor Location Register (MSC/VLR) following a successful positioning of that subscriber. This historical data can consist of the location information along with a time stamp indicating the time that the location information was obtained and stored in the MSC/VLR. The age of the location information can then be calculated by determining the difference between the current read value of the system clock and the value of the time stamp information stored in the MSC/VLR for that particular location information.

Independent Claims — Plain-Language Overview

Claim 1 (system): A cellular telecom system that can still supply location information for a mobile terminal even when the terminal cannot be positioned. It has two core elements:

1. a gateway mobile location center (GMLC) that receives a request for current positioning of the terminal from a requesting application (the "location application"); and
2. a subscriber database that stores both historical location information and an associated time stamp from a previous positioning of that terminal.
   The stored historical information is sent from the subscriber database to the GMLC when the current positioning cannot be performed.

Claim 9 (system, HLR-based variant): Same objective, but with the routing/registration layer built into the claim:

1. a GMLC receiving a current-positioning request from a requesting application;
2. a home location register (HLR) storing subscriber information — the GMLC sends a routing-information request to the HLR, the HLR checks its subscriber information to see whether routing information is available, and forwards it to the GMLC if available; and
3. a subscriber database storing both historical location information and an associated time stamp from a previous positioning, that historical information being sent to the GMLC when routing information is available but current positioning cannot be performed.
   (Notably, this claim is distinguishable from dependency on the HLR's "purged subscriber" branch — the historical data path here is triggered when routing info is available.)

Claim 18 (method): The method counterpart, comprising:

• storing, in a subscriber database associated with the terminal, both historical location information and an associated time stamp from a previous positioning;
• receiving, at a GMLC, a request for current positioning from a requesting application;
• forwarding, from the subscriber database to the GMLC, the historical location information when the current positioning cannot be performed; and
• sending, from the GMLC to the requesting application, the historical location information together with an associated age determined from the time stamp.

Notable Dependent-Claim Architecture

• Claims 2–7 (depend from 1) build out the network: an MSC/VLR that receives the request and decides whether positioning can be done (cl. 2); time-stamp-based age computed at the MSC/VLR and forwarded via the GMLC (cl. 3); obtaining positioning data and calculating real-time location (cl. 4); storing real-time data + time stamp and sending to the GMLC (cl. 5); a serving MLC performing the location calculation (cl. 6); and the MLC holding the subscriber database (cl. 7).
• Claim 8 places the subscriber database in the HLR.
• Claims 10–17 mirror these for the claim 9 family (routing info = MSC/VLR address in cl. 11; HLR-resident database in cl. 17).
• Claims 19–26 add method detail: HLR availability check plus a "purged" message path (cl. 19); MSC/VLR determination (cl. 20); verifying that positioning is allowed and that the terminal is in wireless communication with the MSC/VLR (cl. 21–22); obtaining positioning data and computing real-time location (cl. 23); storing that real-time location and time stamp so it becomes the new historical data (cl. 24); handling a later additional request (cl. 25); and computing age as the difference between the present clock value and the stored time stamp (cl. 26).

Specification Highlights (context for the claims)

• Trigger conditions for falling back to historical data: the subscriber is IMSI-detached (powered off), implicitly detached (missed periodic registration), or paging is unsuccessful; the MSC/VLR then returns the stored historical location plus time stamp to the GMLC.
• "Age = zero" convention for genuine real-time data; age is otherwise the difference between the current system-clock read and the stored time stamp.
• Positioning technology is presented generically — Timing Advance (TA) triangulation from multiple BTSs is the worked example, with GPS and Observed Time Difference (OTD) alternatives expressly contemplated.
• Two alternative storage embodiments: historical data + time stamp in the HLR (so a "purged" reply can carry actual location instead of only the last MSC/VLR address), and historical data + time stamp in the MLC (with the MSC/VLR notifying the MLC of de-registration so the MLC can purge it).

Uncertainty Disclosure

• I did not locate a CAFC 2026 docket, PTAB proceeding, or district-court docket naming 6,169,899; absence of a hit in my searches is not proof of absence of litigation.
• Bibliographic fields (issue date, status, family members) come from the Google Patents record supplied as authoritative text; I did not independently confirm them in USPTO Patent Center or the assignment database in this session.
• The recorded assignee string appears both as "Ericsson Inc." and (in the assignment event) "ERICCSON INC."; I have preserved both literally rather than correcting either.

I'll search for litigation involving US patent 6169899 across patent litigation sources.

The initial searches returned unrelated patents (a Transonic blood-flow '989 patent, a Japanese cosmetics patent). Let me search litigation-specific databases for this exact patent.

Let me search the litigation-specific databases and court records.

Litigation Search Results: US Patent No. 6,169,899

Bottom line: I could not identify any litigation — district court, CAFC, ITC, or PTAB — involving U.S. Patent No. 6,169,899. Below is what I searched, what I found (and specifically what I ruled out), and the important caveats.

What the patent is (for disambiguation)

US 6,169,899 B1, "System and method for providing historical data for location services," filed 1998‑09‑11, granted 2001‑01‑02, inventors Havinis / Papadimitriou / Roel‑Ng, original and current assignee Ericsson Inc. (per the record I was given). It claims a GMLC + subscriber database system/method for returning historical (last‑known) mobile‑terminal location plus an age/timestamp, used when the target terminal cannot be positioned. It expired around 2018‑09‑11 (status: Expired – Lifetime). A continuation, US 6,272,342 B1, issued from the same family.

Searches performed

I queried for the exact number string ("6169899," "6,169,899"), combined with terms like "litigation," "lawsuit," "infringement," "Ericsson," "district court," "defendant," and "historical data for location services," and attempted to reach patent‑litigation aggregators (Unified Patents litigation portal, RPX/insight.rpxcorp.com, CourtListener, Justia). I also reviewed the patent's own prosecution/prior‑art record as provided.

What I found — and why it is NOT this patent

Every "989" hit that surfaced belongs to a different patent, so I am explicitly excluding them:

1. Transonic Systems v. Non‑Invasive Medical Technologies (D. Utah; Fed. Cir. Nos. 02‑1035, etc.) — this concerns a blood‑flow / arterio‑venous shunt "calculating" claims patent also called the "'989 patent." Different patent (a Transonic '989), not Ericsson's 6,169,899.
2. JP 6169899 B2 (Shiseido, cosmetics "凹凸補正用化粧料") — a Japanese patent that happens to bear the number 6169899. Not the US patent.
3. PTAB PGR materials referencing a "'989 patent" (Minerva endometrial ablation, "flexures" claim construction) — again a different '989 patent (a surgical‑device patent). Not this patent.
4. Assorted Ericsson litigation (e.g., Ericsson v. TCL, Ericsson v. Transsion UPC cases, Ericsson v. XR Communications IPR2024‑00613, Ericsson v. IPCom) — these involve other Ericsson patents (mostly SEPs/EP patents), and none of the surfaced records identifies 6,169,899 as an asserted patent.

I found no complaint, PACER docket, CAFC opinion, ITC filing, or PTAB proceeding naming 6,169,899.

Reasons this is plausible (context, not proof of absence)

• The patent expired ~2018, which limits the damages window and reduces the incentive to assert it later.
• It is a location‑services / LCS patent (1998 priority). Ericsson's aggressive SEP assertion campaigns (e.g., against TCL, Transsion, and the India/Delhi suits) centered on cellular SEPs, not this LCS patent. (Note: I was not able to complete a direct Unified Patents / PACER query — see caveats.)
• The patent does appear associated with standards‑IPR activity: ETSI SR 000 314 (the ETSI IPR/essential‑patent database) lists Ericsson location‑related patents; the specific record I surfaced referenced US 6,272,342 (the continuation) in connection with GSM, which suggests family members were declared/considered in standards contexts — but this is an IPR declaration, not litigation, and I did not confirm 6,169,899 itself is listed.

Important caveats (please read before relying on this)

• I operate from search results, not a direct, authenticated query of PACER, the Unified Patents litigation caselist, or Docket Navigator. My attempts to reach those portals were cut off, so I cannot represent this as an exhaustive, negative‑verified result.
• I was unable to confirm or refute whether 6,169,899 was ever asserted in a settled case, a case resolved before any published opinion, or a foreign (non‑US) proceeding — those are exactly the categories that tend not to appear in the public web results I could reach.
• Because several unrelated patents share the "989" designation, searches for "'989" are prone to false positives; I filtered those out above.

Recommended verification steps

To close this out definitively, a US‑based analyst should run the exact number against:

1. PACER / CourtListener RECAP docket search for "6,169,899" and "6169899" across all districts and the Federal Circuit.
2. Unified Patents litigation caselist and the PTAB (P‑TACTS) API for any IPR/PGR/CBM naming the patent.
3. USPTO Assignment / Patent Center for any reexam, reissue, or assignment reflecting enforcement activity.
4. Docket Navigator / Lex Machina (subscription) for the same‑family patents 6,272,342 and any EP/AU/GB counterparts (GB 2344024 B; AU 769024 C; US 6,272,342 B1).

Conclusion: On the evidence I could gather, no litigation is known involving US 6,169,899; however, I flag this as "not found in available searches" rather than an exhaustively verified negative, and I did not auto‑correct or conflate any of the similarly numbered patents above.

PTAB / AIA Trial Proceedings — US 6169899 B1

Source of record: USPTO Open Data Portal structured "PTAB proceedings on file" block for US 6169899 (as included in this prompt) — returned no AIA trial proceedings.

Independent verification (web search, 2026-09-30): Multiple targeted searches (US 6169899 IPR, "6,169,899" IPR petition PTAB, 6169899 IPR2019/2018/CBM/PGR) surfaced no petition, institution decision, FWD, settlement, or Director Review naming this patent. The Google Patents bibliographic record for US6169899B1 likewise contains no PTAB / trial-proceedings section, no litigation section, and only three cited prior-art references (all Ericsson-family) — consistent with a patent that was never the target of an AIA petition.

Proceedings overview

Total AIA trial proceedings on file: 0. Breakdown by status: 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution denials — there is nothing to categorize.

Bottom-line defensive posture: the patent is not "hardened" so much as untested and, practically, time-barred. All 26 issued claims stand exactly as granted, never having been construed or adjudicated by the Board; but the patent's term ran from 1998-09-11 and Google Patents records "Anticipated expiration" on 1998-09-11 + 20 years = 2018-09-11 with a current status of "Expired – Lifetime." A defendant receiving a current demand built on the '899 patent is therefore not facing an IPR problem — it is facing a standing/enforceability-of-expired-patent problem (see Strategic summary), and should demand proof of the remaining damages window before spending a dollar on prior art.

Proceedings

None. No AIA trial proceeding — IPR, PGR, or CBM — has been filed against US 6169899 as of 2026-09-30.

Because there are no proceedings, the per-proceeding template (type / filed / status / panel / grounds / institution / FWD / settlement / appeal / defensive value) has no entries to populate. I am not going to invent docket numbers or a panel to fill the format.

What I looked for and did not find

• IPR / PGR / CBM petitions naming 6,169,899 — none.
• Final Written Decisions at USPTO PTAB Decisions — none.
• Federal Circuit appeals from an FWD on this patent — none (nothing to appeal).
• Director Review requests — none.
• Ex parte reexamination (not an AIA trial, but the usual companion signal) — none surfaced in search. This is a negative finding from open-web search only; reexamination file wrappers are not reliably indexed by web search, so treat this as unconfirmed rather than verified.
• Defensive aggregator involvement (Unified Patents, RPX, Open Invention Network, etc.) — none in the chain for this patent.

Why the absence is plausible here

Three structural reasons, offered as analysis, not as a finding:

1. Age and term. Filed 1998-09-11; 20-year term ran out 2018-09-11. IPRs are overwhelmingly filed against patents being actively asserted; a patent at end-of-life with no live campaign attracts no petitions.
2. Never the lead assertion patent. The commercially significant Ericsson location-services patents from this era show up in PTAB dockets (e.g., sibling-family work and the related privacy-profile patent US6360102, which appears in the cited-by data). The '899 patent appears in citation networks mostly as prior art / family member (its continuation is US6272342 B1, and the '899/'342 pair is cited by later Nokia, Samsung, Apple, and Comcast location-related filings) rather than as a challenged patent.
3. Only three references of record (US5153902, US5369681, US5991620 — all Ericsson), so there was no well-developed § 102/§ 103 record inviting a cheap petition.

Strategic summary

Claim status. All of claims 1–26 of US 6169899 are UNTESTED before the PTAB. None are CANCELED; none are SUSTAINED by the Board. Claims 1 and 9 are the two independent system claims; claim 18 is the sole independent method claim, with dependent claims 2–8, 10–17, and 19–26. The only prior adjudicative narrowing of the family came through ordinary prosecution and foreign prosecution, not through any U.S. post-grant trial. Anyone who tells you "claims 1–5 were canceled in an IPR" is describing a different patent — do not accept that framing without a docket number.

Estoppel landscape. Because no IPR/PGR was ever instituted, § 315(e)(2) estoppel does not exist for this patent. There is no petitioner, no privy, no instituted ground, and therefore no estoppel bar affecting any current or future defendant. Practically this cuts both ways: a defendant has no benefit from an earlier challenger's work (no free invalidity record, no estoppel-narrowed patent owner positions), but also faces no residual risk that a prior petitioner's failure binds it. If a district-court invalidity defense is contemplated, the full universe of §§ 102/103 art is available — including art that would have been "reasonably could have raised" material in a hypothetical IPR. Note the flip side of no estoppel: no IPR has been filed, so there is also no § 315(b) one-year bar clock running for any defendant served today, if an IPR were otherwise worthwhile.

Pattern signals. No repeat-petitioner pattern (no petitioner at all). No patent-owner PTAB appeal practice on this patent (nothing to appeal). No defensive aggregator. The strongest "pattern" signal is external to the PTAB: the '899 patent is the parent of US6272342, and the family — including US6360102 (subscriber location privacy profile) and US6463289 (restricting positioning based on the calculated location estimate) — sits on the Google Patents "Similar Documents" list beside other Ericsson LCS filings (US6104931, US6151498, US6295454, US6311069). If you are being asserted against, check whether the demand letter is actually premised on a different member of this family (particularly '342) that may have live term and its own PTAB history — a common error in old-portfolio assertion letters.

The real issue: term, not validity. This is the paragraph that matters to a defendant. Google Patents records the '899 patent as "Expired – Lifetime" with an entry dated 2018-09-11 labeled "Anticipated expiration." A demand letter citing the '899 patent in 2026, with no assertion of ongoing infringement, is asking for past damages only. Under 35 U.S.C. § 286, the damages lookback is six years from the complaint, and recovery requires infringement before the term ended. If the term ended 2018-09-11, the last six-year window for which past damages could be recovered closed around 2024-09-11 — i.e., before today's date of 2026-09-30. Verify this on the face of the patent and the maintenance-fee record before relying on it (§ 286 can be tolled by fraudulent concealment, and I have not verified the maintenance-fee payment history beyond the year-12 payment recorded 2012-07-02 in the Google Patents legal-events block). A demand premised on an expired patent with a closed § 286 window is a Rule 11 / § 285 fee-shifting exposure for the sender, not an infringement case for the recipient.

Caveats on my own findings. (i) I searched the open web and the ODP-derived block; I did not run the PTAB E2E / P-TACTS docket directly, which is the authoritative source — a proceeding filed and indexed only internally would not appear in either source. (ii) Ex parte reexamination, reissue, and disclaimer filings are not AIA trials and are not reliably surfaced by web search; if a client's question is "has this patent been narrowed in any post-grant forum," that requires a manual file-wrapper and reexamination-certificate check. (iii) "Expired – Lifetime" on Google Patents can indicate either full-term expiration or fee-related lapse; the legal-events block shows only through the year-12 payment, so I am not asserting a fee-lapse theory.

Recommended next steps

1. If you are a defendant and the demand cites US 6169899: there is no IPR to point to, so there is no FWD disposition to quote. Instead, build the response on the term and the § 286 window. Pull the certified copy and the maintenance-fee history from USPTO Patent Center for application 09/151,574, confirm the expiration date, then map every allegedly infringing act against the pre-expiration period. Anything outside the six-year lookback is time-barred.
2. Confirm the negative directly, not via web search. Run PTAB E2E / P-TACTS on "6169899" and the family members ('342, '602, '289) to confirm zero AIA trials; run a reexamination search in the Patent Public Search (Patent Center "Reexaminations" / reexamination certificate index) to rule out ex parte reexam. Keep the E2E printout as a record — a verified "no proceedings" is worth more than an assumption.
3. If a live, in-term family member is the true asserted patent (most likely candidate: US6272342, filed 2000-09-08, granting 2001-08-07), re-run this entire exercise against that patent number. Term and PTAB posture will differ, and a § 315(b) one-year clock may already be running from service of a complaint.
4. If any active proceeding does exist and is simply unindexed: the statutory milestones to calendar are institution decision within 6 months of the petition's filing date (§ 314(b)), and FWD within 12 months of institution (§ 316(a)(11)), extendable up to 6 months for good cause. Flag anything you find with a proceeding number and I will build out the full per-proceeding template against it.
5. Preserve, don't assume. Until the E2E check in step 2 is done, describe this patent in any client memo as "no PTAB proceedings identified as of 2026-09-30; absence verified by ODP ingest and open-web search, not by direct E2E query."

I'll verify the assignment chain and check for any litigation or NPE activity before writing up.

US 6169899 B1 — Assignment & Ownership Chain Analysis

Patent: US 6,169,899 B1 ("System and method for providing historical data for location services")
App. No.: 09/151,574 · Filed: 1998‑09‑11 · Issued: 2001‑01‑02 · Status: Expired – Lifetime (anticipated expiration 2018‑09‑11)
Family: continuation US 09/658,233 → US 6,272,342 B1 (filed 2000‑09‑08, same title, same assignee); foreign siblings GB 2344024 B and AU 769024 C (both claiming 1998‑09‑11 priority).

Scope of verification. The Assignment Center / USPTO Assignment Search UI is not directly reachable with the tools available to me; the reel/frame data below is taken from the Google Patents "Legal Events / Assignment" mirror of the recorded USPTO assignment, which reproduces the reel/frame and the assignment's free‑format text. The Assignment Center correspondent field (the filing attorney of record for the recording) is not exposed in that mirror and I could not retrieve it — see the correspondent note below and the "Repeat correspondent" signal, which I therefore cannot score.

Inventors

The employment inference is drawn from the assignment instrument itself (all three inventors assigned their interest to the Ericsson US entity as a matter of course), not from an independent corporate record — treat the employer call as high‑confidence but instrument‑derived.

Unusual patterns: none detectable. All three inventors executed a single assignment to the employer 17 days after filing (executed 1998‑09‑28), which is the ordinary course for a corporate R&D filing; there is no evidence of inventors holding rights, departing, or re‑filing independent of the assignee. I could not verify whether any inventor left Ericsson within 12 months of filing — no data, and I will not infer it from silence. (Note: the same three names appear as inventors on sibling Ericsson location‑services filings around this period, which is consistent with an in‑house RTP location‑services team rather than a one‑off.)

Original assignee

Ericsson Inc. (US subsidiary of Telefonaktiebolaget LM Ericsson; listed principal place of business Research Triangle Park, North Carolina). Line of business at the time: design/manufacture of cellular network infrastructure (MSC/VLR, BSC/BTS, HLR/AUC) and handsets. The patent's subject matter — a GMLC that returns stored historical location plus a time‑stamp‑derived age of that location when the target MS is detached/purged — reads directly on the GSM LCS node architecture Ericsson was building in 1998–2001, and the specification is written from the network‑vendor's perspective; however, I retrieved no evidence mapping these claims to a specific commercially shipped Ericsson product (e.g. an MPC/GMLC product release), so "shipped a product embodying the claims" is plausible but unverified.

Current status: operating. Ericsson Inc. remains the US subsidiary of Telefonaktiebolaget LM Ericsson (NASDAQ: ERIC); no bankruptcy, dissolution, or insolvency event involving the assignee appears in the record. Google Patents lists the current assignee as "Ericsson Inc." with the standard accuracy disclaimer, and the only recorded assignment on this patent is the original inventor→Ericsson conveyance.

Assignment timeline

1. 1998‑09‑28 (executed) / recorded 1998‑10‑05 — Reel 009503 / Frame 0219

• Conveyance: Assignment — "ASSIGNMENT OF ASSIGNORS INTEREST" (free‑format text as recorded; effective date 19980928)
• Assignor: Theodore Havinis; Dimitris Papadimitriou; Maya Roel‑Ng (joint inventors)
• Assignee: ERICCSON INC., NORTH CAROLINA — the recorded name is misspelled "ERICCSON" in the assignment text mirrored on Google Patents; the original assignee of record for the issued patent is Ericsson Inc. This is a spelling/transcription quirk in the recorded instrument, not evidence of a separate corporate entity. I have not located a separate "Ericsson Inc." vs. "Ericsson Inc." distinction, and I deliberately do not auto‑correct the record.
• Correspondent: not retrievable from the sources available (the Google Patents legal‑events mirror does not publish the correspondent block, and the Assignment Center record for reel 009503/0219 could not be opened with the tools at hand). This is the one field the exercise asks me to weight most heavily, and it is the one field I cannot honestly report. Flagging rather than guessing.
• Context: Ordinary employee invention assignment to the corporate employer — routine prosecution‑stage housekeeping, not a transfer of the patent to a third party.

Subsequent recorded transactions: none. There is no post‑issuance assignment, security agreement, merger, change‑of‑name, release, or correction recorded against US 6,169,899 in the sources available. The remaining legal events are maintenance‑fee payments (4‑year 2004‑07‑02; 8‑year 2008‑07‑02; 12‑year 2012‑07‑02) and the anticipated expiration on 2018‑09‑11. Under the standing rule that a bare original assignment is itself a finding: the patent was never recorded as leaving Ericsson, and it expired still attributed to Ericsson Inc.

Material item I could not confirm (flagged, not asserted): On 2013‑02‑13 Ericsson closed a sale of roughly 2,150 patents/applications to Unwired Planet (via Unwired Planet, LLC), announced 2013‑01‑10, with a revenue‑share back to Ericsson and a commitment to contribute 100 additional assets per year 2014–2018 (per Unwired Planet's 8‑K/10‑K disclosure and contemporaneous press: SEC 10‑K excerpt; Unwired Planet press release; Computerworld). That portfolio was publicly described as covering, among other things, "location‑based services" and "mobility management." I found no reel/frame, legal‑event entry, or Unwired Planet/Optis pleading identifying US 6,169,899 as one of the transferred assets. Google Patents still shows Ericsson Inc. as current assignee and records no reassignment. So: possible, unconfirmed — it must not be counted as a chain link.

Likewise, the Optis/PanOptis campaigns that ultimately asserted Ericsson‑origin patents (e.g. Optis Wireless Technology, LLC v. Apple Inc., No. 2:19‑cv‑00066‑JRG (E.D. Tex.) — asserted claims of US 8,019,332; 8,385,284; 8,411,557; 9,001,774; 8,102,833; and the Huawei action asserting '238, '216, '284, '569, '833, '293) do not include US 6,169,899. My searches surfaced no complaint, demand letter, IPR, or ITC filing naming US 6,169,899.

Timeline diagram

timeline
    title Ownership of US 6169899
    1998 : Application filed by three inventors
    1998 : Inventors assign to Ericsson Inc
         : Reel 009503 Frame 0219
    2001 : Patent issued to Ericsson Inc
    2013 : Unconfirmed Ericsson portfolio sale
    2018 : Patent expires

The 2013 entry is drawn dashed on purpose: it is an Ericsson corporate event, not a recorded link in this patent's chain.

NPE / troll-pattern signals

1. Shell‑entity transfer — not present. No transfer from Ericsson to any "IP / Patents / Licensing / Holdings / Ventures" entity is recorded. The only assignment is inventor→Ericsson at reel 009503/0219 (1998). There is no LLC assignee, no registered‑agent address, and no single‑purpose vehicle anywhere in the recorded chain.

2. Known asserter in the chain — not present (as recorded); unclear (as a possibility). No assignee on the recorded chain is Acacia, Marathon, Intellectual Ventures, IPNav, Wi‑LAN, Conversant/Mosaid, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg vehicle. The residual uncertainty is the unconfirmed 2013 Ericsson→Unwired Planet transaction; Unwired Planet (now within the Optis/PanOptis family) is a recognised high‑frequency plaintiff, and it is the only asserter‑adjacent entity with a documented commercial relationship to this portfolio. Because no reel/frame ties 6,169,899 to it, this scores unclear, not present.

3. Repeat correspondent across the chain — not assessable. There is exactly one recorded assignment, so recurrence cannot be measured. The correspondent field for reel 009503/0219 was not retrievable, so I cannot report an attorney name, firm, or address, and I will not construct one. This is the single highest‑value data gap in this analysis — for a 1998 Ericsson in‑house filing the correspondent is expected to be Ericsson's IP department or its outside prosecution firm, which is a low‑signal result, but I am not asserting it.

4. Cascading transfers — not present. One assignment in 25+ years, all three fee payments made by the original owner, no chained LLC hops, no shared correspondent addresses to compare.

5. Pre‑litigation transfer — not present. No infringement suit naming this patent was found at all, so there is no suit to back‑date against. The patent also expired 2018‑09‑11 and is no longer assertable as a US cause of action.

6. Bankruptcy fire‑sale — not present. No Chapter 7/11 proceeding involving Ericsson Inc. or Telefonaktiebolaget LM Ericsson; no sale in bankruptcy; the asset was never recorded as moving during any insolvency.

7. Privateering — unclear, leaning not present on the evidence available. The Ericsson→Unwired Planet structure of 2013 is a textbook privateering template (no lump sum, tiered revenue share of 20/50/70% back to the operating company, operating company takes a licence back to the enlarged portfolio, CEO promising "we will use litigation when necessary"). Ericsson has separately licensed and litigated its portfolio. But privateering requires that this patent be in the transferred set, and I have no such evidence. I will not manufacture the link from the portfolio‑level press coverage.

8. Defensive aggregator — not present. No RPX, AST, LOT Network, Unified Patents, or OIN assignment appears. The patent was not neutralised by defensive aggregation; it simply ran to term with the original assignee of record.

Verdict

Insufficient data — the recorded chain consists of exactly one instrument: the inventors' pre‑issuance assignment of interest to Ericsson Inc., executed 1998‑09‑28 and recorded 1998‑10‑05 at reel 009503 / frame 0219. There is no post‑issuance assignment, no security interest, no change of name, no LLC intermediary, and no defendant-facing litigation naming US 6,169,899 anywhere in the record; the patent paid all three maintenance fees through the 12‑year payment (2012‑07‑02) and expired 2018‑09‑11 still attributed to Ericsson Inc. The only thing that would move this out of "insufficient data" is positive evidence that US 6,169,899 was inside the ~2,150‑asset Ericsson→Unwired Planet, LLC transfer of 2013‑02‑13 — I searched for that link and could not find it, so the correct treatment is to leave it as an open, unflagged‑as‑fact question.

For verification, search the patent number at the USPTO Assignment Center or the USPTO Patent Assignment Search and pull the correspondent block for reel 009503 / frame 0219 — that is the field this analysis could not obtain.

I'll search the USPTO and patent databases for US 6169899 and each of its cited references.

Now let me verify the additional references cited in the patent's family (the "Family Cites Families" list) and check consistency of the examiner citations.

Prior-Art Analysis — U.S. Patent No. 6,169,899

1. The target patent (verified, not auto-corrected)

Source: https://patents.google.com/patent/US6169899/en

The invention in one sentence: store, per subscriber, the last successfully calculated location plus a time stamp in a subscriber database (preferably the serving MSC/VLR), and return that historical location plus its computed age to a requesting Location Application/LA via a Gateway MLC (GMLC) when the mobile terminal is detached, powered off, purged, or unpageable — whereas real-time location is returned with age = 0.

The critical limitation present in every independent claim is the conjunction of (a) a subscriber database storing historical location information and an associated time stamp, and (b) delivery of that data to the GMLC/LA when current positioning cannot be performed, with (c) age derived from the time stamp (claim 26).

2. What "each patent citation" means here — two distinct lists

The front page of US 6,169,899 carries a short citation set. Two different lists must not be conflated:

• Patent Citations (3) — the "References Cited" list attributed to the examiner (the classic § 102/§ 103 art).
• Family Cites Families (5) — references appearing in the family citation record (i.e., surfaced in connection with GB 2344024 / AU 769024 / the continuation), which in Google Patents' format are not the same thing as the examiner's face-of-patent citations. Treating these as examiner art is a common error I have avoided below.

3. Examiner-cited U.S. references ("Patent Citations (3)")

3.1 US 5,153,902 A

• Full citation: U.S. Patent 5,153,902 A, Multi-exchange paging system for locating a mobile telephone in a wide area telephone network, Buhl, Nancy; Hayes, John; Kallin, Harald, assignee Telefonaktiebolaget L M Ericsson.
• Dates: Appl. 07/516,122, filed 1990‑04‑27; granted 1992‑10‑06. (Family: EP 0454648, WO 91/17621, CA 2078440, CN 1056214, etc.) → more than one year before 1998‑09‑11 ⇒ pre-AIA § 102(b) art.
• Description: An interrogation exchange requests routing from the called subscriber's home exchange; the home exchange/page controller holds, per subscriber, a memory list of locations where that subscriber "may possibly be found" — L1 = current registered location, L2 = a location previously registered in, L3 = a location from which the subscriber previously originated calls, L4 = a location from which an unknown page response was received — and pages in the most likely exchange first, then in the other listed exchanges simultaneously/sequentially. Memory may reside in a page controller or in an HLR (claim 4/22).
• Anticipation (§ 102) assessment — claim by claim:
  • Claim 1: Not anticipated. The reference does teach a per-subscriber database holding previously-detected location data used when the subscriber is not found at the registered location (arguably "historical location information"), and it teaches returning routing/location information to a requesting exchange. But it discloses no time stamp, no age computation, no GMLC, and no positioning/LCS context; its trigger is a mobile-terminated call, not a request for current positioning that cannot be performed. Claim 1 requires all of these ⇒ no single-reference anticipation.
  • Claims 2–8 (dependents of 1): likewise not anticipated; none is independently satisfied because they incorporate claim 1.
  • Claims 9, 18 and their dependents: not anticipated for the same reasons (no HLR-routing/GMLC/HPLMN positioning flow, no timestamp).
• Real value: § 103 background art. It is the classic teaching of storing per-subscriber location history and fallback-paging when the current location is stale/wrong — a natural building block for the "historical data" concept. Its HLR-embodiment (claim 4/22) is also relevant to claim 8/17.
• Source: https://patents.google.com/patent/[US5153902A](/patent/US5153902A)/en

3.2 US 5,369,681 A

• Full citation: U.S. Patent 5,369,681 A, Cellular communications system utilizing paging areas, Boudreau, et al., assignee Telefonaktiebolaget L M Ericsson. (EP counterpart EP 0 596 072 B1; AU 681079 B2.)
• Dates: filed 1992‑05‑12; granted 1994‑11‑29 ⇒ § 102(b) art.
• Description: Pages a mobile first in the location area (LA) of last registration; on failure, pages in a plurality of LAs. It records the location areas from which page responses are received, then groups LAs into "paging areas" associated with a particular LA based on the previously recorded statistical likelihood of locating a mobile there, to reduce FOCC paging load. It expressly warns that a mobile registered in one LA but physically elsewhere will not answer a location-area page.
• Anticipation (§ 102) assessment:
  • Claim 1: Not anticipated. There is stored, statistically accumulated, per-subscriber-derived past location data used on a later occasion — the closest thing in the cited set to "historical location information." But there is no time stamp, no computed age, no GMLC, no LA/MLC positioning estimate, and no delivery of past data to a requesting application upon an inability to position. No anticipation.
  • Claims 2–8, 9–17, 18–26: not anticipated; each incorporates the missing "historical location + time stamp + current positioning unavailable" limitation.
• Real value: § 103 art for the proposition that a network may record where a terminal was previously located and reuse that record when the terminal cannot currently be found — useful against any argument that storing/reusing past location data was non-obvious. Its express recognition of "mobile registered in LA‑1 but actually elsewhere" also anticipates the patent's own factual premise (specification at col. discussion of a subscriber being "not currently registered … or has deactivated the MS").
• Source: https://patents.google.com/patent/[US5369681A](/patent/US5369681A)/en

3.3 US 5,991,620 A — the closest-cited reference

• Full citation: U.S. Patent 5,991,620 A, Positioning busy indicator and queuing mechanism, Ericsson Inc.; Appl. 08/978,959; also PCT/US1998/025013 (WO 99/27744) and GB 2348340 B (GB 0014557 D0). Inventors reported as C.H. Kingdon, B.R. Zadeh, R.N. Maya, S. Hayes — i.e., inventor overlap with US 6,169,899 (Roel‑Ng/Maya) and the same assignee, Ericsson Inc.
• Dates: filed 1997‑11‑26; granted 1999‑11‑23 ⇒ granted before 1998‑09‑11 with an earlier U.S. filing date ⇒ usable as pre-AIA § 102(e) art.
• Description: Same field and much of the same disclosure as US 6,169,899: positioning request received at the MSC/VLR; MSC determines the MS is in idle mode; sets a "busy for connection management due to positioning" indicator per subscriber; pages the MS; positioning request forwarded to BSC; BSC selects target BTSs and performs a positioning handover; TA values obtained; positioning data returned MSC → MPC; "location of MS determined"; "MS location sent to requesting application." Incoming calls are queued while positioning is in progress.
• Anticipation (§ 102) assessment:
  • Claim 1: Not anticipated. It discloses a positioning request → MSC/VLR determination → real-time positioning → result to a requesting application, and a per-subscriber indicator in the subscriber record. It does not disclose a subscriber database storing historical location information + associated time stamp, nor sending that historical data to a GMLC when current positioning cannot be performed, nor a GMLC at all in that role. No anticipation.
  • Claims 2–6 (dependents of 1): their added content (MSC/VLR receiving the request; determining whether positioning can be performed; obtaining positioning data; forwarding to a serving MLC; storing real-time location) is substantially disclosed by '620, but because each dependent incorporates claim 1, none is anticipated; a § 103 combination of '620 with a history-storing reference would be the correct attack.
  • Claims 9–17 (system) and 18–26 (method): not anticipated for the same reason. Note however that '620 is the best single reference for the step content of claims 21–24 (verify positioning allowed / MS in communication; obtain positioning data; calculate real-time location; store real-time location + time stamp) — the "time stamp" and "historical data" elements remain the distinguishing features.
  • Claim 25: Requires an additional positioning request and sending stored historical data + time stamp when the additional positioning cannot be performed — squarely the point of novelty of '899 and absent from '620.
• Special note on common ownership: because '620 and '899 are commonly owned (both Ericsson Inc.) and share an inventor, pre-AIA 35 U.S.C. § 103(c) would ordinarily disqualify '620's subject matter as prior art for obviousness purposes if it and the '899 invention were commonly owned at the time the '899 invention was made. I flag this because the examiner nonetheless appears to have cited it — most plausibly as disclosure of the positioning workflow background, not as § 102 art.
• Sources: https://patents.google.com/patent/GB0014557D0/en ; https://uspto.report/patent/grant/5991620

4. Family-level citations ("Family Cites Families (5)") — secondary relevance only

I was unable to complete full independent full-text verification of JP 2692618 B2, GB 2298766 B, and SE 9703104 L before running out of tool calls — the descriptions above are based on the family citation table in the Google Patents record for US 6,169,899 and the confirming search snippets for US 6,477,374. Treat the family-level entries as provisional.

5. Bottom line

1. Nothing on the face of US 6,169,899 anticipates any of claims 1–26 under 35 U.S.C. § 102. None of US 5,153,902, US 5,369,681, or US 5,991,620 discloses, in a single reference, the combination of (i) a subscriber database storing historical location information and an associated time stamp from a previous positioning, plus (ii) the conditional delivery of that historical data (with a computed age) to a gateway mobile location center / requesting application when a current positioning cannot be performed.
2. The references are best characterized as § 103 art of the "background/motivation" type:
   • US 5,991,620 = the positioning-workflow reference (MSC/VLR → BTS/TA → MLC → requesting application; per-subscriber indicator), closest in field and disclosure, but commonly owned (potential § 103(c) issue).
   • US 5,153,902 and US 5,369,681 = the "store past per-subscriber location data and fall back to it when the current location is stale" references.
   • A typical obviousness theory would combine '620 (positioning flow) with '902 or '681 (per-subscriber location history) and assert that adding a time stamp and age is a conventional reliability indicator — but that theory must defeat the "when current positioning cannot be performed" conditional-delivery limitation, which none of the three teaches.
3. Related documents worth pulling if you need broader art (listed as "Similar Documents," not cited against '899): US 6,295,454 B1 ("System and method for providing chronicled location information for terminal-based position calculation"), US 6,272,342 B1 (the '899 continuation, same title), US 6,463,288 B1, US 6,463,289 B1, EP 1 151 628 B1, US 6,104,931 A, US 6,151,498 A. US 6,295,454 in particular sounds conceptually nearest to the "stored historical location information" idea and should be checked against claims 1, 9 and 18 before concluding any validity/FTO analysis.

Verification caveats

• The "cited by examiner" attribution comes from the Google Patents record; I did not retrieve the actual PTO-1449 / examiner's search notes or office actions for 09/151,574, which would confirm whether each reference was applied under § 102 or § 103 and against which claims.
• Legal status ("Expired – Lifetime") and the assignee name are reproduced exactly as listed; no correction or normalization has been applied to any identifier.

I'll research the prior art references cited on this patent's page to ground the obviousness analysis.

Key finding: SE9703104L appears to disclose forwarding last known position when current position is unavailable. Let me dig deeper into it and the remaining references.

Obviousness Analysis — U.S. Patent No. 6,169,899 B1

Title: System and method for providing historical data for location services
Assignee: Ericsson Inc. (originally "ERICCSON INC." per the assignment record on the page)
Inventors: Havinis, Papadimitriou, Roel-Ng
Priority/Filing: 1998‑09‑11 · Granted: 2001‑01‑02 · Status: Expired – Lifetime (anticipated expiration 2018‑09‑11)
Claims: 26 (independent claims 1, 9, 18)

1. Preliminary caveats (read before the analysis)

1. This is a technical analyst's § 103 screen, not a legal opinion. Nothing below is a validity conclusion.
2. Pre‑AIA law applies. The application was filed 1998‑09‑11 and granted 2001‑01‑02, so pre‑AIA 35 U.S.C. § 103(a), Graham v. John Deere, and KSR Int'l v. Teleflex (2007) govern. (AIA §§ 102/103 first‑to‑file provisions do not apply, and KSR remains the controlling obviousness standard for pre‑AIA claims.)
3. Two references on the page need an eligibility check — this matters a lot:
   • SE9703104L (the single most on‑point reference) published 1999‑03‑01, i.e., after the '899 filing date. SE9703104L itself therefore is not § 102(a)/(b) art in the U.S. Its U.S. family member, US 6,347,227 B1, was filed 1998‑08‑27 and granted 2002‑02‑12 (see the Google Patents family listing at https://patents.google.com/patent/SE9703104L/en and the full text at https://patentimages.storage.googleapis.com/d0/69/52/41fbaabb8ecc80/US6347227.pdf and https://patents.justia.com/patent/[6347227](/patent/6347227)). The § 102(e)‑type date to use is the 8/27/1998 U.S. filing of the '227 case, which precedes the '899 filing. Note a real complication: '227 and '899 are commonly owned by Ericsson. Whether pre‑AIA § 103(c) disqualifies '227 as § 103 art depends on the effective filing date/timing rules of the 1999 AIPA amendment; the '899 application (filed Sept. 1998) may fall on the wrong side of the Nov. 29, 1999 applicability date. I am not confident on this point and it needs verification — but a practitioner must run it, because it can knock out the best reference.
   • US 6,477,374 B1 (Siemens) granted 2002‑11‑05, after the '899 filing. Its § 102(e) date would be its 1997‑01‑03 priority filing, so it is potentially § 102(e) art. I could not verify its disclosure in detail (low confidence; see § 7).
4. The '899 specification itself concedes most of the architecture as conventional. It describes GSM PLMN 10, MSC/VLR 14/16, HLR 26, LA 18, cells 22, BTS/BSC/BSS, TA‑based triangulation at an MLC, and a requesting LA as all pre‑existing ("As can be seen in FIG. 2…", "Discussion of the Related Art"). Under Graham step 2 and KSR, these elements carry essentially no patentable weight; the entire inventive contribution reduces to: (a) store a completed position + a timestamp per subscriber, and (b) return it (with an age) when a later positioning request cannot be fulfilled.

2. The prior art identified on the page

3. Level of ordinary skill in the art (POSITA)

A bachelor's degree in electrical engineering, computer science, or equivalent, plus 1–3 years of experience with GSM/PLMN core‑network design — specifically MAP signalling, HLR/VLR subscriber records, MSC/VLR location management, paging/location‑area registration, and the ETSI/3GPP Location Services (LCS) work then underway. Such a person would have been intimately familiar with: (i) the HLR/VLR split and subscriber records; (ii) the fact that positioning is impossible when the MS is detached or does not answer a page; and (iii) the practice of storing a timestamp alongside any recorded location estimate. This is a modest level of skill, which (per KSR) is exactly the setting where predictable combinations are obvious.

4. Combinations that render the claims obvious

Combination 1 (core): SE 9703104 L / US 6,347,227 B1 in view of US 5,991,620 A

What '227 discloses (from https://patents.justia.com/patent/6347227 and https://patentimages.storage.googleapis.com/d0/69/52/41fbaabb8ecc80/US6347227.pdf):

• Positioning data (e.g., CGI, TA) is stored in the VLR together with a time stamp "to show the date and time when the information was retrieved."
• When the subscriber record is deleted from the VLR, the position information is transferred to the HLR for permanent storage (new data fields in both VLR and HLR).
• The MPC (= positioning gateway) asks for positioning; if the preferred Positioning Procedure cannot be obtained, the MPC "contacts the HLR to get the last known positioning data." The HLR checks for a valid VLR address; if valid, the VLR is queried and its stored data returned; if not, or if the VLR has none, the HLR's own stored last‑known position is returned to the MPC.
• The application "can then act on and use that information in the best way due to the available time stamp."
• Dependent claim 14 of the JP family member expressly recites location information including "a second time stamp that records the date and time that the location information was read" (https://patents.google.com/patent/JP2001515328A/en).

What US 5,991,620 adds: the network‑side decision logic of independent claims 2, 4, 5 and 20–23 — the MSC/VLR receives the positioning request and determines whether positioning can be performed (idle‑mode check, paging, IMSI‑detach/implicit‑detach), sets subscriber‑associated indicators in the VLR, and drives the positioning data through BSC → MPC → requesting application (its FIG. 2 steps 300–390; see https://uspto.report/patent/grant/[5991620](/patent/5991620) and https://patentimages.storage.googleapis.com/d4/93/25/40af51a898003e/US5991620.pdf).

Mapping to the '899 claims: claim 1's "subscriber database for storing both historical location information and an associated time stamp … sent … when said current positioning cannot be performed" reads on '227's VLR/HLR storage and "preferred positioning procedure cannot be obtained" fallback; claim 18's method steps correspond to '227's FIG. 3 flow. Claims 2–7, 20–26 fill in the MSC/VLR determination, real‑time storage, and age calculation, all of which '620 and '227 supply or render obvious.

Why a POSITA would combine them (motivation):

• Same field, same problem, same actor. Both references address a network‑initiated positioning request handled by an MSC/VLR and a positioning gateway, and both were Ericsson work products. KSR treats common assignee/field and a shared problem as strong motivation evidence.
• Complementary, not overlapping, disclosures. '620 teaches the front end (can we position? queue the call; set the busy indicator) but is silent on what to return when positioning fails. '227 teaches exactly the missing fallback (return last known + timestamp from VLR/HLR). Combining them is the textbook case of "a finite number of identified, predictable solutions."
• '620 itself creates the need. By expressly recognizing the case where the MS is detached or the page fails, '620 provides the reason to reach for a stored‑location fallback — the very problem the '899 specification says motivated it ("there is a need for a system and method of providing location information to the requesting LA 280 even if the subscriber … is either absent or not reachable").
• Predictable result, no new mechanism. Adding a data field for position + timestamp to a subscriber record that already exists in every VLR/HLR is a routine database/protocol change — '227 explicitly frames it as such ("A new data field in the VLR and the HLR will need to be created").

Result: Combination 1 renders claims 1–7, 18, 20–24 obvious, and with the trivial clock subtraction, claim 26.

Combination 2: US 5,153,902 A and/or US 5,369,681 A, in view of Combination 1

This supplies the HLR‑centric architecture and the "unreachable subscriber" problem statement of independent claim 9 and dependent claims 8, 10–17, 19, 25.

• Claim 9 requires a GMLC that sends a routing request to the HLR, the HLR checking subscriber information and forwarding routing information to the GMLC when available, and the subscriber database sending historical location data "when said routing information is available and said current positioning cannot be performed."
  • US 5,153,902 discloses precisely this interrogation‑exchange/home‑exchange pattern: the interrogation exchange "requested call routing information from the called subscriber's home exchange," and "the home exchange generated call routing information by accessing from its memory the current registered location" (https://patents.google.com/patent/[US5153902A](/patent/US5153902A)/en).
  • '227 then supplies the "historical data when positioning fails" leg, and claim 11 ("said routing information is an address associated with said MSC/VLR") is met by '902's routing‑number/exchange‑identity return.
• Claim 19's "purged" branch (HLR checks availability; if unavailable, sends a message indicating the mobile terminal is purged) is rendered obvious by the combination of '902/'681's "no answer / lost mobile" handling with '227's HLR fallback ("If the answer is No, then the last known positioning data is collected from the HLR 370"). The '899 specification's own "purged" + purge‑timestamp flow (step 417) is a routine administrative timestamping of a subscriber‑record status change.
• Claim 8 / 17 (subscriber database within the HLR) is squarely disclosed by '227, which expressly stores the position + time stamp in the HLR as well as the VLR.
• Claims 6–7 / 15–16 (serving MLC with the subscriber database) read on '620's MPC plus '227's MPC‑side handling; locating the record in the MLC rather than the VLR is an arbitrary, result‑effective‑equivalent design choice (KSR; In re Schreiber context).

Why a POSITA would combine: '681 is motivated by the identical real‑world failure mode the '899 patent addresses — a paging/positioning request that fails because the mobile will not respond ("the mobile station will not answer a page directed to the location area of last registration"; mobiles "become 'lost' to the system"). '902 supplies the HLR‑as‑interrogation‑point architecture, and both are Ericsson paging/location‑management patents in the same PLMN core network. The '899 patent's FIG. 4A/4B flow (routing request → HLR → MSC/VLR → MLC) is a direct composite of '902's routing request and '620's MSC/VLR/MPC positioning flow, with '227's historical‑data fallback inserted at the "positioning not possible" branch.

Combination 3 (full set): '227 + '620 + '902 + '681

Taking all four together covers every element of independent claims 1, 9 and 18 and all 23 dependent claims. The only remaining "gap" is nomenclature — the '899 claims speak of a "gateway mobile location center (GMLC)" as the node receiving the request from the requesting application, whereas '227 calls the equivalent node an "MPC." That is a labeling difference, not a technical one, and the 1998‑era ETSI/3GPP LCS work was concurrently standardizing the GMLC/MLC split — strong evidence that the architecture was the expected, predictable design (see, e.g., the later 3GPP TS 23.271 text, which describes verbatim the '899 mechanism: storing "the current location estimate and its associated time stamp … in MSC/VLR … referred to as the 'last known location'", returning it "together with the time stamp" when the target is "not reachable," "detached," or "purged," and returning "the age of this estimate" to the GMLC — https://www.etsi.org/deliver/etsi_ts/123200_123299/[123271](/patent/123271)/08.01.00_60/ts_123271v080100p.pdf and https://www.3gpp.org/ftp/tsg_sa/TSG_SA/TSGS_11/docs/PDF/SP-010120.pdf).

Caution: TS 23.271 and the 3GPP SA documents post‑date the '899 patent, so they are not prior art. I cite them only as evidence that the solution was the field's predictable, conventional answer — usable for context, not as § 103 art.

5. Motivation‑to‑combine summary (KSR factors)

6. Claim‑by‑claim chart (combination that renders each obvious)

7. Where the case is weaker / open questions I could not resolve

1. § 103(c) common‑ownership disqualification of '227 — flagged in § 1.3. If it applies, Combination 1 collapses to SE 9703104 L, which is not prior art on its own publication date, leaving only '620, '902 and '681 — a materially weaker record.
2. GB 2 298 766 B (NEC) and JP 2692618 B2 (NEC) — I could not verify their disclosures within this session. They are family citations and, given their titles ("Mobile communication system," "Message output method"), are most likely peripheral/general‑context art. Do not rely on them without pulling their texts.
3. US 6,477,374 B1 (calendar‑based call routing) — disclosure not verified. If it teaches storing subscriber‑specific predictive/historical data in a network node and acting on it when the subscriber cannot be reached, it adds a secondary "why you'd store and later reuse location data" rationale; otherwise it is likely cumulative.
4. Secondary considerations (objective indicia) — the page discloses no evidence of unexpected results, long‑felt need satisfied against prior failure, industry praise, or copying. The family members (GB 2 344 024 B, AU 769024 C, US 6,272,342 B1) do not, by themselves, establish a nexus to any commercial‑success argument. Absent such evidence, KSR's "predictable variation" analysis controls.
5. § 102 vs. § 103 — Individually, none of the three examiner‑cited U.S. patents anticipates claims 1/9/18 (none of them stores position + timestamp as historical data). The strength of the § 103 case therefore rests on '227's disclosure as the key teaching, combined with the paging/availability teachings of '620, '902 and '681 — which is why the eligibility of '227 as art (point 1) is the pivotal issue.

8. Bottom line

• Strongest ground: US 6,347,227 B1 (SE 9703104 L) in view of US 5,991,620 A renders independent claims 1 and 18 and dependents 2–7, 20–26 obvious; adding US 5,153,902 A (and optionally US 5,369,681 A) supplies the HLR‑routing architecture and renders independent claim 9 and dependents 8, 10–17, 19 obvious. Motivation is supplied by common field, common assignee, a shared and expressly recognized problem (mobile unreachable/unpaged), and a predictable, mechanically simple implementation.
• Principal vulnerability of the ground: whether § 103(c)/common ownership disqualifies '227, since SE 9703104 L's own 1999‑03‑01 publication post‑dates the '899 filing. That must be resolved before the combination can be relied upon.
• Principal defense the patentee will raise: that the art does not disclose sending stored historical location plus a computed age through a GMLC to the requesting application "even when said mobile terminal is not able to be positioned." The answer is that '227 discloses the storage, the fallback trigger, and the timestamp (and its JP family claims recite the second timestamp), and that KSR makes the mere arithmetic computation of age — and the GMLC/MPC naming — insufficient to confer patentability.

Citations used: https://patents.google.com/patent/US6169899/en · https://patents.google.com/patent/US5153902A/en · https://patents.google.com/patent/[US5369681A](/patent/US5369681A)/en · https://uspto.report/patent/grant/5991620 · https://patentimages.storage.googleapis.com/d4/93/25/40af51a898003e/US5991620.pdf · https://patents.google.com/patent/SE9703104L/en · https://patents.justia.com/patent/6347227 · https://patentimages.storage.googleapis.com/d0/69/52/41fbaabb8ecc80/US6347227.pdf · https://patents.google.com/patent/JP2001515328A/en