US 5689252

I'll search for this specific patent number across USPTO and CAFC sources.

Let me refine the search with targeted queries for the patent record and any 2026 appellate activity.

Let me do one more targeted check for recent appellate or litigation activity.

US 5,689,252 — Search Results Summary

Scope note: I searched the open web for the literal identifier "5689252" / "5,689,252" across patent and litigation sources. I could not query a live CAFC docket system directly; the results below reflect what web search surfaced. I found no CAFC 2026 docket activity for this patent — see "Litigation posture" below for what I did and did not find, and treat the absence as "not found," not as proof of absence.

Bibliographic data (US 5,689,252 A)

Sources: https://patents.google.com/patent/US5689252/en ; https://uspto.report/patent/grant/5689252 ; https://idiyas.com/patent/badge/5689252

Abstract (as filed)

"A navigation system for an automotive vehicle designed to display a road map image around the vehicle in correlation with the current position of the automotive vehicle. The navigation system is adapted to determine a best navigation route to a selected destination on the basis on the approximated time necessary to travel such a navigation route in correspondence to its travel length and speed rate."

Core technical disclosure

The system uses GPS (with LORAN, dead-reckoning, or radar as alternatives) plus optional direction sensor 28 and distance sensor 30 for positioning; a CD-ROM 24 or equivalent for map storage; a CRT 20 and keyboard/touch-panel input 25; and a traffic information receiver 32 that pulls traffic data wirelessly from a central database 50. Each stored road map is converted to a data structure with at least two fields per street: speed and length. Route selection is by computed travel time (length ÷ speed) rather than by shortest distance.

Notably, the patent claims a bandwidth-reduction scheme: traffic data is transmitted as variable-length differences from locally stored speed limit values, with no transmission when the difference is inconsiderable, and coarse quantization (e.g., a 12 mph reduction sent as 10 mph). The central database can also average position/speed reports crowdsourced from mobile users, and can itself compute and transmit the best route.

Independent claims — plain language

Claim 1 — Vehicle navigation system (apparatus). A vehicle navigation system that identifies a desired map route between a first position and a second position, comprising: (a) map storage holding road maps and speed limit values for roads; (b) user input to select the two positions; (c) means to select the relevant road map based on those positions; (d) a traffic receiver that gets traffic information including speed rates over a wireless channel from a centrally located database, transmitted as variable-length differences from the stored speed limit values; and (e) means to determine the route of shortest duration from the received speed rates and route length.

Claim 11 — Vehicle navigation system (improvement format). A system with positioning means, display means, and map storage (map plus road speed limit values), wherein the improvement is: best-route determining means that identifies and displays the best route based on time required to travel, together with a traffic receiver that gets speed-rate traffic information over a wireless channel from a central database in the variable-length-difference format relative to stored speed limits.

Claim 18 — Method (database-centric routing). Steps: determine the vehicle's actual position; select a destination; transmit position and destination to a central database; at the database, select the best route based on stored traffic speed rates; transmit the best route back to the vehicle as map information; and periodically transmit positions and speed rates from many vehicles to the database; average those speed rates at the database; and push updated traffic information based on that averaging.

Claim 19 — Method (on-board routing). Steps: (a) determine actual position; (b) store road maps with speed limit values; (c) select a destination from a stored map; (d) identify candidate routes; (e) receive traffic information including speed rates for those routes, transmitted over a wireless channel from a central database as variable-length differences from the stored speed limit values; (f) determine travel time for each route from the received traffic information; and (g) select the route with the shortest travel time.

Notable dependent claims

• Cl. 2 — map means is a CD-ROM device.
• Cl. 3–4 — input means includes positioning means; display of actual position on the selected map.
• Cl. 5–7 — central database stores/transmits maps; time computed via speed rate; traffic info displayed with vehicle position.
• Cl. 8 — central database includes typical seasonal and daily traffic patterns.
• Cl. 9 — each street record includes speed rate and length.
• Cl. 10 & 13 — no speed-rate data transmitted where the difference from the speed limit is inconsiderable (transmission-time reduction).
• Cl. 12 & 17 — vehicles periodically upload position and speed; database averages across vehicles and retransmits.
• Cl. 14–15 — travel time = length ÷ speed rate; traffic info displayed on the display means.
• Cl. 16 — vehicle transmits position + destination; database computes and returns the best route.
• Cl. 20–22 — dividing length by rate; displaying the vehicle position on the map; displaying the best route and traffic information.

(Literal-text observations: claim 3 recites that "said input means includes positioning means"; claims 12 and 17 recite "means in said actual database," where the specification refers to the "central database." I am reporting these exactly as the claim text reads rather than correcting them.)

Litigation / PTAB posture (what I found)

• IPR2015-00706 — ZTE (USA) v. Vringo Infrastructure Inc., Patent Trial and Appeal Board, filed Feb. 5, 2015, concerning patent 5689252; Google Patents lists it as procedurally terminated. Source: https://www.docketalarm.com/search/PTAB/?q=Trevor+Jefferson (and the Google Patents litigation block).
• Feb. 2015 — ZTE publicly stated it applied to the USPTO to re-examine five Vringo patents, explicitly listing US 5,689,252 among them (along with US 7,558,283; US 6,081,534; US 7,126,940; US 7,724,720). Source: https://www.businesswire.com/news/home/20150211006009/en
• Related foreign counterpart — European Patent (DE) 0,710,941 was among the Vringo/ZTE European suits referenced in Vringo's disclosures; EP0710941B1 is in this patent's family.

Uncertainty / caveats

1. No CAFC 2026 docket entry referencing 5689252 was found. My searches returned 2026 Federal Circuit materials on unrelated patents (e.g., Ironburg v. Valve, No. 2024-1520/2025-*, U.S. Pat. 7,679,637; Rideshare Displays v. Lyft; Vroom v. Sidekick; Viken Detection v. Videray), none involving 5689252. Given the patent expired 2014-11-04 and the 2015 IPR terminated procedurally, an active 2026 appeal would be unusual — but I cannot affirmatively rule one out, because I could not run a docket-level query.
2. Assignee data is derivative of USPTO assignment records as aggregated by Google Patents; the source itself cautions that listed assignees "may be inaccurate." The current-assignee string (Vringo Infrastructure Inc.) should be verified against USPTO Assignment records if it matters.
3. The abstract and claim text above are quoted directly from the Google Patents full text; I treated that as authoritative rather than any secondary summary.