Invalidity dossier
US 6016311
Adaptive time division duplexing method and apparatus for dynamic bandwidth allocation within a wireless communication system
Current assignee: Cisco Technology Inc
Added 9/23/2026, 5:42:35 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 6016311A
Title: Adaptive time division duplexing method and apparatus for dynamic bandwidth allocation within a wireless communication system
Patent number: US 6016311A
Application number: US08/974,376
Inventors: Sheldon L. Gilbert, Rami Hadar, Israel J. Klein
Original assignee: Ensemble Communications Inc.
Current assignee (as listed): Cisco Technology Inc
Priority/filing date: 1997-11-19
Publication (grant) date: 2000-01-18
Legal status (as listed): Expired – Lifetime; anticipated expiration 2017-11-19
Purpose
The invention relates to wireless point-to-multipoint voice, data and video ("broadband") communication systems, and more particularly to adaptive time division duplexing for dynamic bandwidth allocation. Wireless systems provide communication channels on demand between subscriber units and a base station connecting users to fixed network infrastructure. Frames of time are the basic transmission unit, divided into slots; some slots are used for control and others for information transfer, with slots assigned to specific subscriber units. Duplexing permits exchange of information in both directions: base-station-to-subscriber transmissions are "downlink," and subscriber-to-base-station transmissions are "uplink."
Plain-language scope (from the excerpt)
The background contrasts two duplexing approaches. Frequency division duplexing (FDD), used in GSM and IS-54/IS-136 TDMA systems, requires frequency separation between uplink and downlink bands, a duplexor at the subscriber antenna, and allocates equal or symmetrical bandwidth for both directions — limiting flexibility and spectrum, especially for broadband. In time division duplexing (TDD), duplexing occurs in the time domain on a single radio frequency, simplifying frequency reuse, but subscriber modems become more complex because they are active only part of the time. The excerpt describes the problem space and existing standards (Japanese and European DCT/DECT, with specified carrier spacing and frame/slot structures), including a 5 ms frame with four transmit and four receive slots and 625 microsecond slots with roughly 30 microsecond guard times.
Not established by the excerpt
The supplied text does not include the claims, detailed description of the adaptive allocation mechanism, drawings, or specific embodiments. It does not establish validity, infringement, litigation, or ownership-transfer accuracy. Any characterization of the invention's actual scope must come from the full patent, not this excerpt. Some text is truncated at the end.
Source: https://patents.google.com/patent/[US6016311](/patent/US6016311)/en
Generated 10/1/2026, 9:43:23 PM
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Litigation summary
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Proceedings on file (0)
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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
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
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.