Invalidity dossier
US 8284686
Antenna/beam selection training in MIMO wireless LANS with different sounding frames
Current assignee: Freedom Patents LLC
Added 9/23/2026, 3:28:26 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
US8284686B2 — Patent Overview
Title: Antenna/beam selection training in MIMO wireless LANS with different sounding frames
Patent number: US8284686B2 | Application: US12/293,458
Inventors: Daqing Gu, Hongyuan Zhang, Jinyun Zhang, Andreas F. Molisch
Original assignee: Mitsubishi Electric Research Laboratories Inc. (Current assignee listed as Freedom Patents LLC in the supplied text.)
Key dates: Priority date 2005-11-21 (claimed from PCT/US2005/042358); filing date 2006-03-30; publication of US20090290563A1 on 2009-11-26; granted/publication of US8284686B2 on 2012-10-09. Status listed as Active, with adjusted expiration 2028-03-26.
Purpose and plain-language scope: The patent concerns training for antenna/beam selection in MIMO wireless LANs. Per the title, the training involves different sounding frames — that is, sounding packets used to probe the channel so a transmitter/receiver can pick antennas or beams. The prior-art keywords supplied (sounding, packets, packet, antenna selection, zlf) indicate the disclosure centers on sounding-packet-based antenna selection, including a zero-length-frame (ZLF) type of sounding packet.
What the supplied excerpt does not establish:
- It does not include the claims, detailed description, or drawings (the excerpt notes text was omitted and the image area is blank). Therefore no specific claim scope, claim language, or claim limitations can be stated.
- It does not establish the number or exact content of the "different sounding frames," how they differ, or the selection algorithm.
- It does not establish validity, enforceability, or the accuracy of the listed assignees, legal status, or expiration date (Google expressly labels these as assumptions/not legal conclusions).
- It does not establish priority entitlement or prior-art effect; priority is likewise labeled an assumption.
- It does not establish litigation or ownership-transfer details beyond the bare entries supplied, which are outside the requested scope.
Source: https://patents.google.com/patent/[US8284686](/patent/US8284686)/en
Generated 10/1/2026, 9:51:34 PM
Cases on file (0)
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Litigation summary
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Proceedings on file (0)
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No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
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
Earlier patents, publications, and products that may anticipate or render the claims unpatentable.
Obviousness
Combinations of prior art that suggest the claimed invention would have been obvious under 35 U.S.C. § 103.
Extensions
Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.
Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.