Prior art — US Patent 11997568

Based on the newly provided authoritative text for US patent 11,997,568, the previous analyses dated April 26, 2026, and May 6, 2026, are now superseded. The patent does exist and has an active legal status. This report provides an analysis of the prior art cited during its prosecution.

Analysis of Prior Art Cited Against US Patent 11,997,568

The following analysis focuses on the prior art references cited by the USPTO examiner during the prosecution of the application for patent 11,997,568. These references are considered the most relevant for assessing the patent's novelty. The core inventive concept of US patent 11,997,568 revolves around granting a non-subscriber temporary access to a Push-to-Talk-over-Cellular (POC) talkgroup by transmitting a communication that includes a link to download the required software application.

1. US 2018/0278718 A1 (Motorola Solutions, Inc.)

Full Citation: US Patent Application Publication No. US 2018/0278718 A1, "Method and apparatus for a cloud-based broadband push-to-talk configuration portal," published September 27, 2018.
Filing Date: March 24, 2017.
Brief Description: This document describes a cloud-based configuration portal for managing a broadband Push-to-Talk (PTT) system. An administrator can use the portal to provision and configure talkgroups, add or remove users, and set user permissions. The system is designed to allow an agency (like a public safety organization) to manage its own PTT services without deep technical knowledge.
Potential Anticipation Analysis: This reference is highly relevant as it discloses a centralized, cloud-based system for managing PTT talkgroups.
- Anticipation of Claim 8 & 15: The Motorola reference describes an administrator provisioning users for PTT services. This aligns with the limitations of a "control device" (the cloud-based portal) receiving information (from an administrator, analogous to a "first subscriber device") and granting a user access to a talkgroup. However, Motorola appears to focus on provisioning known users or subscribers within an agency or system. It does not explicitly teach the specific step of granting access to a "first non-subscriber device" and, crucially, does not disclose the step of transmitting a communication including a link to download a POC software application to that non-subscriber. The '718 application seems to assume the user devices are already equipped with or will be provisioned with the necessary client software through other means. Therefore, it fails to anticipate the complete combination of elements in claims 1, 8, and 15 of US 11,997,568.

2. US 2007/0117552 A1 (Ecrio, Inc.)

Full Citation: US Patent Application Publication No. US 2007/0117552 A1, "Push to talk over cellular having productive use of dead time and inclusion of diverse participants," published May 24, 2007.
Filing Date: January 9, 2006.
Brief Description: This publication details a Push-to-Talk over Cellular (PoC) system that allows for the inclusion of "diverse participants." This includes bringing users of different communication systems (e.g., landline phones, non-PoC mobile phones) into a PoC session. The system can send invitations to these external users, for example via an SMS message.
Potential Anticipation Analysis: This reference discloses the concept of inviting users who are not regular subscribers of the primary PoC service into a talkgroup.
- Anticipation of Claim 8 & 15: Ecrio teaches sending an invitation (e.g., an SMS) to a non-PoC device based on their contact information (like a phone number), which aligns with receiving "non-subscriber contact information" and "granting...access." However, the method of inclusion described by Ecrio involves bridging the external user into the session, for instance by having the system place a regular voice call to their landline or mobile phone, rather than provisioning them as a temporary PoC user. It does not teach the key step recited in claims 1, 8, and 15 of US 11,997,568: transmitting a communication that includes a link to download a POC software application. By not providing the non-subscriber with the native PTT client, Ecrio's system is architecturally different and does not anticipate the claims of the '568 patent.

3. US 2016/0065742 A1 (Verizon Patent and Licensing Inc.)

Full Citation: US Patent Application Publication No. US 2016/0065742 A1, "Conference call systems and methods," published March 3, 2016.
Filing Date: August 27, 2014.
Brief Description: This document describes a system for managing conference calls. It discloses a method where a user can be sent a link, and clicking that link can automatically dial the user into a conference call. The system can also include a link to a web-based client or a downloadable application for participating in the conference.
Potential Anticipation Analysis: This reference, while directed at general conference calls rather than PTT, discloses a very similar workflow of inviting a user via a link that facilitates joining a communication session.
- Anticipation of Claim 1, 8, & 15: The Verizon reference comes close to anticipating the claimed invention. It teaches sending a communication (e.g., email or text message) to a participant that contains a link. This link can lead to a downloadable application to join the call. This maps to the elements of "granting...access" and "transmitting...a first communication including a link to download a...software application." However, the claims of the '568 patent are specifically limited to a Push-to-Talk-over-Cellular (POC) talkgroup and POC service. Verizon describes a general conference call system, which is typically full-duplex, not the half-duplex, arbitrated communication that defines POC systems. The examiner likely concluded that one of ordinary skill in the art would not have considered a standard conference call system to be the same as a POC system, and therefore this reference does not anticipate the specific context of the claims. Furthermore, the '568 patent's dependent claims (e.g., claim 2) which add the limitation of automatically revoking access further distinguish it from a general-purpose conference call invitation system.

4. US 2006/0252442 A1 (Nokia Corporation)

Full Citation: US Patent Application Publication No. US 2006/0252442 A1, "Method for establishing a PoC connection in a terminal device with a touch-screen display, an application used in the method and a terminal device," published November 9, 2006.
Filing Date: May 4, 2005.
Brief Description: This publication from Nokia describes a user interface method for establishing a PoC call. It focuses on how a user can select contacts from an address book displayed on a touch screen to initiate a group PoC session.
Potential Anticipation Analysis: This reference is relevant as it deals directly with the initiation of PoC sessions.
- Anticipation of Claim 8 & 15: The Nokia reference describes a user selecting contacts from a list on a "subscriber device" to initiate a PoC call. This is analogous to "transmitting...non-subscriber contact information." However, the entire context of the application is about inviting other PoC-capable subscribers who are already part of the user's contact list and presumably already have the PoC application. It does not disclose the scenario of inviting a true non-subscriber (a user without the service or application) nor does it teach the critical step of transmitting a link to download the POC software. It therefore fails to anticipate the claims of US 11,997,568.