PTAB challenges

Proceedings overview

One Inter Partes Review (IPR) has been filed against US patent 11,997,568. The proceeding is currently pending, meaning no claims have been invalidated or sustained yet. For a defendant, this means the patent is actively being challenged at the USPTO, and the outcome could significantly impact its enforceability.

IPR2026-00348 — AT&T Services, Inc. et al. v. BK Technologies Inc.

• Type: Inter Partes Review
• Filed: 2026-05-05
• Status: Pending. The petition has been filed, but the Patent Trial and Appeal Board (PTAB) has not yet decided whether to institute a trial.
• Judge panel: Not yet assigned.
• Petition grounds: The petition challenges claims of US patent 11,997,568. While the full petition is not provided, the grounds likely assert that the claims are obvious under 35 U.S.C. § 103. Strong arguments for obviousness can be made by combining prior art references that teach the key elements of the claims, such as:
  • US 2018/0278718 (Motorola), which discloses a cloud-based PTT management portal, combined with US 2016/0065742 (Verizon), which teaches sending a user a link to download a required software application for a communication session. The motivation to combine would be to improve Motorola's system by adding a conventional and well-known method for onboarding external users who lack the necessary software.
  • US 2007/0117552 (Ecrio), which teaches inviting non-subscribers to a POC session via a bridge, combined with US 2016/0065742 (Verizon). The motivation here would be to improve Ecrio’s rudimentary bridging method with Verizon’s more modern and functional approach of providing a direct download link for the native client, allowing the non-subscriber to participate fully.
• Institution decision: A decision on whether to institute the IPR has not yet been issued. The Patent Owner has approximately three months from the filing date to submit a Patent Owner's Preliminary Response (POPR). The Board will then issue its institution decision within three months of the POPR filing. The statutory deadline for the institution decision is approximately 2026-11-05.
• Final Written Decision: Not applicable. If the trial is instituted, a Final Written Decision (FWD) would be due within one year of the institution date (approximately late 2027).
• Settlement / termination: No settlement has been recorded. The proceeding is in its earliest stage.
• Appeal: Not applicable.
• Defensive value: The filing of this IPR by a major entity like AT&T provides significant defensive value. The petition document itself is a roadmap to invalidating the patent and can be used to inform defensive strategy. A defendant should closely monitor this proceeding, as a decision to institute would indicate the PTAB believes there is a "reasonable likelihood" the petitioner will prevail in invalidating at least one claim. A defendant could also leverage the pending IPR to seek a stay of any concurrent district court litigation.

Strategic summary

Currently, all claims of US patent 11,997,568 remain valid and enforceable, as no claims are CANCELED or SUSTAINED through a PTAB trial. The entire patent is now being challenged in IPR2026-00348. The outcome of this proceeding will determine the final status of the challenged claims.

The estoppel landscape under 35 U.S.C. § 315(e)(2) has not yet attached. If the IPR proceeds to a Final Written Decision, the petitioner (AT&T and its real parties-in-interest) will be estopped from asserting in district court any invalidity ground that it raised or reasonably could have raised during the IPR. For any other defendant, all prior art grounds remain available. The arguments laid out in the IPR petition, particularly the obviousness combinations, are now publicly available and can be adopted by others. There are no signals of multiple IPRs by the same petitioner or other unusual patterns at this time, as this is the first and only proceeding filed against the patent.

Recommended next steps

For a defendant facing an assertion of this patent, the immediate priority is to monitor the status of IPR2026-00348. The public documents for this proceeding can be accessed via the USPTO's PTAB E2E portal.

Key upcoming milestones to watch for are:

• Patent Owner's Preliminary Response Deadline: Approximately August 2026.
• Institution Decision Deadline: Approximately November 2026. This is the most critical near-term event. An institution decision in favor of the petitioner would significantly weaken the patent owner's position.
• Final Written Decision Deadline: If instituted, approximately November 2027.

A defendant should obtain a copy of the IPR petition filed by AT&T, as it will contain detailed invalidity arguments and expert testimony that could be directly leveraged in a defensive strategy or a separate PTAB filing. If a district court case has been filed, a defendant should strongly consider filing a motion to stay the case pending the outcome of this IPR.