Invalidity dossier
US 5159592
Network address management for a wired network supporting wireless communication to a plurality of mobile users
Current assignee: International Business Machines Corp
Added 9/23/2026, 4:46:25 PM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview: US 5,159,592 A
Title: Network address management for a wired network supporting wireless communication to a plurality of mobile users
Patent number: US5159592A | Application: US07/605,592 | Inventor: Charles E. Perkins | Assignee: International Business Machines Corp. (original assignee; assignment recorded to International Business Machines Corporation, a Corp. of New York)
Dates: Filed 1990-10-29; priority 1990-10-29; granted/published 1992-10-27; anticipated expiration 2010-10-29; legal status listed as Expired – Lifetime. Later JP, EP, and DE priority filings are listed.
Purpose: Internet protocols assumed users would connect at fixed locations and be assigned unique Internet addresses. Portable and handheld computers violate that assumption because users migrate about the network. The invention addresses assigning IP addresses to mobile units that do not maintain a fixed connection relationship with the network.
Plain-language scope (from the excerpt): A wired network (e.g., TCP/IP LANs) supports mobile communication units that communicate wirelessly via header stations and a wired LAN. A local gateway couples a wireless network to the wired network; a global gateway couples to local gateways and remote users. The global gateway maintains a plurality of network addresses and, on request from a mobile unit, assigns one address to that unit; it buffers and routes data from remote users to the mobile unit at the assigned address. Addresses are allocated and deallocated from a pool available for a "pseudo-network"; permanent pseudo-address assignment is also within scope. Routers are instructed to forward packets destined for the designated network to the global gateway. Wireless medium may be infrared or RF. Figures 3–6 are flowcharts of interactions among mobile units, gateways, and remote users.
Source: https://patents.google.com/patent/US5159592/en
What the excerpt does not establish: It gives no claims text, no detailed description, no complete reference numerals, no examples beyond partial ones, and no litigation, ownership-transfer, validity, or prior-art analysis. The excerpt is explicitly partial, so omitted text should be consulted directly.
Generated 10/1/2026, 9:44:12 PM
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Litigation summary
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PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.