Invalidity dossier
US 8411608
Efficient and reliable multicast over a Wi-Fi network
Current assignee: Microsoft Technology Licensing LLC
Added 9/23/2026, 3:33:08 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
US 8,411,608 B2 — "Efficient and reliable multicast over a Wi-Fi network"
Source: https://patents.google.com/patent/US8411608/en
Bibliographic data (from the supplied text): Application US12/714,360; filed 2010-02-26; priority date 2010-02-26; published as US20110211517A1 on 2011-09-01; granted 2013-04-02. Original assignee [Microsoft Corp.](/litigations/by-plaintiff/Microsoft%20Corp.); current assignee listed as Microsoft Technology Licensing LLC (assignment recorded 2014-12-09). Legal status listed as "Expired – Fee Related," adjusted expiration 2031-04-16. Inventors: Ranveer Chandra, Sandeep P. Karanth, Thomas Moscibroda, Vishnu Navda, Jitendra D. Padhye, Ramachandran Ramjee, Lenin Ravindranath Sivalingam.
Purpose: To improve multicast performance over Wi-Fi (IEEE 802.11) networks while minimizing airtime consumed by multicast traffic and impact on other wireless traffic. The excerpt identifies known 802.11 multicast problems: no ACK requirement, so lost multicast packets are not retransmitted at the MAC layer; no backoffs, causing unfairness to unicast clients; and a static, low basic link data rate used to guarantee coverage. Solutions requiring MAC changes are described as impractical given deployed hardware.
Plain-language scope (per the excerpt): A "Wi-Fi Multicaster" uses a network-based proxy server (also called a "central controller") sitting between conventional multicast servers and conventional access points. It intercepts multicast packets, converts them to unicast packets targeted to dynamically selected "target clients" from a larger multicast group, and provides the unicast packets to APs for transmission. Other clients receive these packets by listening in a "promiscu[ous]" mode. Client association, optional rate control, and optional redundancy optimization use feedback from a "client proxy" component on participating clients. The approach targets single-hop infrastructure wireless networks and requires no changes to the 802.11 standard or to existing AP functionality; only clients wishing to join multicast sessions need software changes.
What the excerpt does not establish: It does not include the claims, detailed description, or figures; does not list cited prior-art references; and does not support any statement about litigation, validity, infringement, or ownership beyond the recorded assignment noted above.
Generated 10/1/2026, 9:51:30 PM
Cases on file (0)
Specific litigation cases in our database that name US patent 8411608. The free-form analysis below may also discuss cases beyond this list.
No cases on file mention this patent. Upload a CSV or add a case manually in Admin → Manage litigation cases.
Litigation summary
Past and pending lawsuits — plaintiffs, defendants, jurisdictions, outcomes, and notable rulings.
Proceedings on file (0)
All PTAB activity →AIA trial proceedings (IPR / PGR / CBM) filed at the USPTO Patent Trial and Appeal Board against this patent. Sourced from the USPTO Open Data Portal and refreshed every six hours; each proceeding number deep-links to the PTAB E2E docket.
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.