US 11089450

Here's a concise summary of US Patent 11089450, based on the provided patent text:

US Patent: 11089450

• Title: Messaging service in a wireless communications network
• Assignee: Rembrandt Messaging Technologies LP [cite: US11089450B2]
• Inventors: Graham Merrett [cite: US11089450B2]
• Filing Date: December 13, 2019 [cite: US11089450B2]
• Issue Date: August 10, 2021 [cite: US11089450B2]
• Abstract: A method may comprise receiving a first message formatted according to an SMS format, by a first mobile wireless device from a second mobile wireless device, via a mobile operator base station. The first mobile wireless device may subscribe to a service for transmitting and receiving packet switched messages, via the Internet and the mobile operator base station. The method may further comprise retrieving, by the first mobile wireless device, information corresponding to at least one mobile phone number of the second mobile wireless device and transmitting, by the first mobile wireless device, after the subscribing, a request including at least the information corresponding to the at least one mobile phone number of the second mobile wireless device, to determine whether the mobile wireless device corresponds to a subscriber of the service. [cite: US11089450B2]

Plain-Language Overview of Independent Claims:

• Claim 1 (Method for First Mobile Wireless Device - SMS initiated): This claim describes a method where a first mobile device receives an SMS message from a second mobile device. After the first device subscribes to a packet-switched messaging service (not SMS, MMS, or EMS), it sends a request using the second device's phone number to check if the second device is also a subscriber. If the second device is a subscriber, the first device then formats a new message using the packet-switched service's format (not SMS, MMS, or EMS). The initial SMS message is received before the first device subscribes to the packet-switched service. [cite: US11089450B2]

• Claim 9 (Method Performed by First Mobile Wireless Device - SMS initiated, no mobile operator base station mentioned initially): Similar to Claim 1, this claim outlines a method performed by a first mobile wireless device. It receives an SMS message from a second device, then subscribes to a packet-switched messaging service via the Internet. After subscribing, it transmits a request with the second device's phone number to check if the second device is a service subscriber. Upon receiving a positive response, the first device formats a second message using the service's specific format (not SMS, MMS, or EMS). The first message is received before the subscribing. A key distinction here from Claim 1 is the explicit omission of "via a mobile operator base station" for the initial reception of the first message, and it also specifies that the first device may not have the second device's username or email in memory at the time of the request. [cite: US11089450B2]

• Claim 15 (Method for First Mobile Wireless Device - MMS initiated): This claim describes a method where a first mobile device receives an MMS message from a second mobile device via a mobile operator base station. After the first device subscribes to a packet-switched messaging service (not SMS, MMS, or EMS), it sends a request using the second device's phone number to check if the second device is also a subscriber. If the second device is a subscriber, the first device then formats a new message using the packet-switched service's format (not SMS, MMS, or EMS). The initial MMS message is received prior to the first device subscribing. [cite: US11089450B2]

• Claim 24 (Method Performed by First Mobile Wireless Device - MMS initiated, no mobile operator base station mentioned initially): Similar to Claim 15, this claim details a method performed by a first mobile wireless device. It receives an MMS message from a second device via a mobile operator base station, then subscribes to a packet-switched messaging service via the Internet. After subscribing, it transmits a request with the second device's phone number to check if the second device is a service subscriber. Upon receiving a positive response, the first device formats a second message using the service's specific format (not SMS, MMS, or EMS). The first message is received before the subscribing. Similar to the distinction between Claim 1 and Claim 9, this claim highlights that the first mobile wireless device may not have a user name or email address associated with the second mobile wireless device in memory at the time of transmitting the request. [cite: US11089450B2]

Litigation Information:

The Google Patents page indicates that the family for US11089450B2 has litigation. Specifically:

• A US case was filed in the Texas Western District Court (case/1:24-cv-01199). [cite: US11089450B2]
• A PTAB case IPR2025-01493 was filed (Not Instituted - Procedural). [cite: US11089450B2]
• First worldwide family litigation was filed. [cite: US11089450B2]

Regarding CAFC 2026 dockets, a direct search for "11089450" within the provided CAFC search results did not yield specific dockets for this patent number. The available CAFC search results offered general information and scheduled cases for May, June, and July 2026 but did not provide a function to search for specific patent numbers in litigation. Therefore, I cannot definitively confirm specific CAFC dockets for US11089450 from the live search at this time.

Known litigation involving US patent 11089450 includes:

1. District Court Case:

   • Jurisdiction: Texas Western District Court
   • Case Number: 1:24-cv-01199
   • Filing Date: Not explicitly provided in the snippet, but the case was "filed" in 2024.
   • Outcome/Current Status: Critical; still active as of the information provided.
   • Plaintiff(s): Not explicitly stated in the snippet.
   • Defendant(s): Not explicitly stated in the snippet.

2. PTAB Case:

   • Jurisdiction: Patent Trial and Appeal Board (PTAB)
   • Case Number: IPR2025-01493
   • Filing Date: Not explicitly provided in the snippet, but the case was "filed" in 2025.
   • Outcome/Current Status: Not Instituted - Procedural.
   • Plaintiff(s) / Petitioner: Not explicitly stated in the snippet.
   • Defendant(s) / Patent Owner: Not explicitly stated in the snippet.

3. First Worldwide Family Litigation:

   • Details for this litigation are linked to Darts-ip via the patent family ID 39735458, but specific case details (plaintiff, defendant, jurisdiction, case number, filing date, and status) for US11089450 are not directly presented in the provided snippets from this source.

Proceedings overview

One AIA trial proceeding has been filed against US patent 11089450. The sole proceeding resulted in a discretionary denial of institution, meaning all claims remain untested by PTAB. This gives a defendant a stronger defensive posture regarding the patent's validity, as it has survived an IPR challenge without any claims being invalidated.

IPR2025-01493 — [Apple Inc.](/litigations/by-plaintiff/Apple%20Inc.) v. Rembrandt Messaging Technologies LP

• Type: Inter Partes Review
• Filed: 2025-08-29
• Status: Discretionary Denial. The PTAB declined to institute the IPR.
• Judge panel: A panel of Administrative Patent Judges from the Patent Trial and Appeal Board. Specific judge names are not publicly available in the provided data or readily discoverable for a discretionary denial status without access to the full PTAB record.
• Petition grounds: Details regarding specific claims, prior art, and statutory bases (§ 102 / § 103 / § 112) for the petition are not publicly available within the provided summary for a discretionary denial. This information would typically be found in the filed petition and the institution decision.
• Institution decision: Denied (Discretionary Denial) on 2026-04-20. The panel's reasoning for a discretionary denial is not explicitly provided in the available data. Discretionary denials often occur under 35 U.S.C. § 314(a) for various reasons, such as parallel district court litigation considerations (e.g., Fintiv factors) or other procedural issues.
• Final Written Decision: Not applicable, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: No appeal to the Federal Circuit, as there was no Final Written Decision to appeal.
• Defensive value: The discretionary denial of IPR2025-01493 means that the claims of US11089450 were not substantively challenged or invalidated by the PTAB in this proceeding. For a defendant, this means that the patent's validity remains intact from a PTAB perspective, and any future IPR challenges would need to present new, compelling arguments or demonstrate why a discretionary denial is no longer warranted.

Strategic summary

All claims of US11089450 remain UNTESTED at the PTAB, as the single IPR filed against it, IPR2025-01493, was denied institution on discretionary grounds. This means no claims have been canceled or sustained by a PTAB Final Written Decision. The patent owner, Rembrandt Messaging Technologies LP, successfully defended against this IPR challenge without undergoing a full trial.

The estoppel landscape remains open for a defendant currently facing assertion. Since IPR2025-01493 was denied institution, § 315(e)(2) estoppel does not apply to Apple Inc. or its privies for any grounds raised or that reasonably could have been raised in that petition. This implies that potential future petitioners are not barred from asserting the same or similar prior art grounds against the patent, though they would need to address the basis for the previous discretionary denial. The petitioner, Apple Inc., is a significant operating company, and their decision to file an IPR suggests they perceived a threat from this patent.

Recommended next steps

For a defendant facing assertion of US11089450, the discretionary denial of IPR2025-01493 indicates that the patent has not been weakened by PTAB proceedings. If considering an IPR, it would be crucial to analyze the specific reasons for the discretionary denial in IPR2025-01493 (e.g., Fintiv factors) to understand how to overcome such a hurdle in a new petition. Accessing the full PTAB record for IPR2025-01493 via USPTO PTAB E2E (https://ptab.uspto.gov/#/search/documents) would be essential to review the petition, patent owner's preliminary response, and the institution decision. This would provide insight into the arguments made and the Board's specific reasoning for the denial, informing whether a subsequent IPR is viable and what strategy it should employ.

Inventors

Graham Merrett.
At the time of the earliest priority date (July 24, 2007), Graham Merrett was with Messmo Technologies Pty. Ltd., an Australian entity, from 2007-2009. He described Messmo as an "early to market mobile over the top (OTT) messaging service, acquiring over 2 million subscribers".

Original assignee

Rembrandt Messaging Technologies LP.
The original assignee, Messmo Technologies Pty. Ltd. (Messmo), was a mobile internet texting platform that enabled users to share text and attachments such as audio, images, and video. Messmo ceased commercial operations in 2009 or 2010.
Rembrandt Messaging Technologies LP itself is an NPE, or "patent asserter." It does not appear to ship products embodying the claims, but rather is involved in patent assertion campaigns.

Assignment timeline

(No recorded assignments were found for US Patent 11089450 on the USPTO Assignment Center as of 2026-05-23. The Google Patents record indicates "Current Assignee: Rembrandt Messaging Technologies LP" and "Original Assignee: Rembrandt Messaging Technologies LP", suggesting no assignments have been recorded against the patent number since issuance, or that any prior assignments were recorded against parent applications).

Timeline diagram

timeline
    title Ownership of US 11089450
    2007 : Priority date by Messmo Technologies
    2019 : Application filed by Rembrandt Messaging Technologies LP
    2021 : Patent issued to Rembrandt Messaging Technologies LP
    2024 : HBCU Messaging US LP (formerly Rembrandt Messaging Tech II) sues Apple

NPE / troll-pattern signals

1. Shell-entity transfer — present. Messmo Technologies Pty. Ltd., the original operating company, ceased commercial operations in 2009 or 2010. In 2014, Messmo assigned its patent portfolio to Rembrandt Messaging Technologies, LP. Rembrandt Messaging Technologies, LP, and its related entities (Rembrandt Messaging Technologies II, LP, and Rembrandt IP Management, LLC) are described as an "IP monetization firm." The current owner, HBCU Messaging US LP (f/k/a Rembrandt Messaging Technologies II, LP), is a subsidiary of the HBCU Technology Foundation, which has accused Apple and Green Dot of infringement. These entities do not appear to ship products embodying the claims.

2. Known asserter in the chain — present. Rembrandt Messaging Technologies, LP, is explicitly identified as a "Patent Asserter" in the Stanford NPE Litigation Database and has a history of patent assertion campaigns. HBCU Messaging US LP (f/k/a Rembrandt Messaging Technologies II, LP) is also actively asserting patents.

3. Repeat correspondent across the chain — unclear. Without access to the actual recorded assignments on the USPTO Assignment Center for US11089450 or its parent applications, it's not possible to identify correspondent attorneys and firms.

4. Cascading transfers — unclear. The publicly available information from RPX and Mondaq indicates Messmo assigned the patents in 2014 to Rembrandt Messaging Technologies, LP, which then assigned US assets to Rembrandt Messaging Technologies II, LP, and then subsequently these entities were transferred to HBCU Tech Holding I, LLC and HBCU Tech Holding II, LLC, wholly owned subsidiaries of the HBCU Tech Foundation. This describes multiple transfers, but without specific recording dates and reel/frame numbers, it's not possible to confirm if they occurred in a cascading fashion within 24 months.

5. Pre-litigation transfer — present. Messmo assigned the patent portfolio to Rembrandt Messaging Technologies, LP in 2014. A German infringement action against Apple (and others) using a European counterpart of these patents was filed in June 2015, which is within 6 months of the 2014 assignment from Messmo. More recently, HBCU Messaging US LP (f/k/a Rembrandt Messaging Technologies II, LP) sued Apple and Green Dot in October 2024, and the transfer to HBCU Messaging US LP (from Rembrandt Messaging Technologies II, LP) was part of a decision by the Rembrandt entities to work with the HBCU Tech Foundation regarding the asserted patents, suggesting this transfer enabled the current litigation.

6. Bankruptcy fire-sale — not present. While Messmo ceased commercial operations, there is no indication of a formal bankruptcy proceeding and fire-sale of its assets.

7. Privateering — unclear. While the original operating company (Messmo) ceased operations, and the patents were transferred to an NPE (Rembrandt entities), there's no explicit evidence in the provided snippets of Rembrandt (or HBCU Messaging US LP) asserting on Messmo's behalf against specific competitors of Messmo.

8. Defensive aggregator (anti-NPE) — not present. The chain leads to HBCU Messaging US LP, which is actively asserting the patent, not neutralizing it.

Verdict

NPE — high confidence
This verdict is based on multiple strong signals: the transfer from an operating company (Messmo) that ceased operations to a known patent asserter (Rembrandt Messaging Technologies LP and its successors, HBCU Messaging US LP), and the pre-litigation transfers where the assignment of the portfolio to Rembrandt entities in 2014 preceded a German infringement action in 2015, and a later transfer to HBCU Messaging US LP preceded a US infringement action in 2024.

Verification of assignment records can be performed at the USPTO Patent Assignment Search: https://assignmentcenter.uspto.gov/

Here is an analysis of the most relevant prior art cited against US patent 11089450, interpreting patent numbers literally as per the operating rules. The focus is on potential anticipation under 35 U.S.C. § 102, requiring a single prior art reference to disclose every element of a claim.

The independent claims of US11089450 (Claims 1, 9, 15, 24) describe a method performed by a first mobile wireless device involving:

1. Receiving a first message (SMS or MMS) from a second mobile wireless device.
2. Crucially, this first message is received prior to the first device subscribing to a new service.
3. The first device subscribing to a service for transmitting and receiving packet-switched messages, where this service's format is explicitly not SMS, MMS, or EMS format.
4. After subscribing, the first device transmits a request to determine if the second device (sender of the original message) is a subscriber of this new service.
5. Receiving a response indicating the second device is a subscriber.
6. Formatting a second message in accordance with this new service's distinct message format, based on the successful subscription and the response.

Many cited prior art references discuss aspects of messaging interoperation, packet-switched messaging, or bearer selection. However, the precise sequence of events, particularly the timing of subscription to a new, distinct packet-switched service relative to receiving an initial legacy message, the subsequent verification of the original sender's status within that new service, and the explicit exclusion of legacy formats for the new service's messages, forms the core distinguishing features of US11089450's independent claims.

Below are the cited prior art references from US11089450, along with their details, a brief description, and an assessment of their potential to anticipate claims under 35 U.S.C. § 102:

Most Relevant Prior Art Analysis

1. US5729544A

   • Full Citation: US5729544A - Method for transmitting data packets based on message type - Motorola, Inc.
   • Publication/Filing Date: Priority: 1994-05-09; Publication: 1998-03-17
   • Brief Description: This patent describes a method for transmitting data packets in a communication system by converting messages from a mobile unit into data packets and routing them over a packet data network based on message type.
   • Potential Anticipation (35 U.S.C. § 102): This reference addresses network-level routing of data packets. It does not disclose the specific user-centric method steps of US11089450, such as receiving an SMS/MMS prior to subscribing to a new packet-switched service, then verifying the original sender's subscription to this new service, and formatting a message in a non-SMS/MMS/EMS format. Therefore, it does not anticipate claims 1, 9, 15, or 24.

2. WO2001041477A1

   • Full Citation: WO2001041477A1 - Instant messenger system and instant message transfer method using phone number as instant messenger address - Arreo Communications Inc.
   • Publication/Filing Date: Priority: 1999-12-03; Publication: 2001-06-07
   • Brief Description: This patent describes an instant messenger system that uses a mobile phone number as the primary identifier for instant messaging, removing the need for separate usernames.
   • Potential Anticipation (35 U.S.C. § 102): This reference is highly relevant as it teaches using a mobile phone number as an identifier for an instant messaging (packet-switched) service, aligning with aspects of US11089450. It potentially discloses elements related to identifying subscribers by phone number (e.g., in claims 7, 10, 19, 20, 26, 28, 30). However, it does not explicitly disclose the specific sequence of receiving an SMS/MMS prior to subscribing to such a service, followed by verification of the original sender's subscription status to that specific new service, and then formatting a message in a distinct non-SMS/MMS/EMS format.

3. US20020077131A1

   • Full Citation: US20020077131A1 - Dual protocol GPRS message center and method therefor - Jerry Mizell
   • Publication/Filing Date: Priority: 2000-12-20; Publication: 2002-06-20
   • Brief Description: This application describes a message center supporting both SMS and GPRS (a packet-switched protocol) for message delivery, allowing selection of the appropriate protocol based on various factors.
   • Potential Anticipation (35 U.S.C. § 102): This reference is relevant for disclosing dual-protocol messaging and bearer selection (SMS vs. packet-switched). While it covers the technical capability to choose a bearer, it does not detail the user-level subscription to a new service after receiving an initial message, the verification of the sender's subscription to this new service, or the constraint on the new service's message format. Thus, it does not anticipate claims 1, 9, 15, or 24.

4. US20030040300A1

   • Full Citation: US20030040300A1 - Method and apparatus for sending a short message service (SMS) message to a multimedia messaging service (MMS) user using email - Hewlett-Packard Development Company, L.P.
   • Publication/Filing Date: Priority: 2001-08-20; Publication: 2003-02-27
   • Brief Description: This application details a method for allowing SMS messages to be sent to MMS users by converting them into an email format.
   • Potential Anticipation (35 U.S.C. § 102): This patent focuses on interoperability through message conversion. It lacks the unique sequence of steps of US11089450's claims, specifically the user subscribing to a new packet-switched service after receiving an SMS/MMS, and then performing a subscription verification of the original sender for that new service. It does not anticipate claims 1, 9, 15, or 24.

5. US20030096608A1

   • Full Citation: US20030096608A1 - System and method for providing an instant messaging service with a short message service (SMS) gateway - Ericsson AB
   • Publication/Filing Date: Priority: 2001-11-20; Publication: 2003-05-22
   • Brief Description: This application describes an instant messaging system that incorporates an SMS gateway to enable communication between SMS users and instant messaging users.
   • Potential Anticipation (35 U.S.C. § 102): This is highly relevant as it discloses the interworking of SMS and IM (packet-switched messaging) via a gateway. It teaches how an SMS could be received and processed by an IM system. However, it typically focuses on the technical bridging rather than the specific user-initiated workflow of US11089450, particularly the "prior to subscribing," "after the subscribing" for sender verification, and the explicit "not SMS/MMS/EMS" format constraint for the new service's messages. It does not fully anticipate claims 1, 9, 15, or 24.

6. US20040002334A1

   • Full Citation: US20040002334A1 - Method and system for providing packet-switched based mobile messaging - Nokia Corporation
   • Publication/Filing Date: Priority: 2002-06-25; Publication: 2004-01-01
   • Brief Description: This application describes a method and system for providing mobile messaging services primarily over packet-switched networks, offering enhanced features compared to traditional circuit-switched messaging.
   • Potential Anticipation (35 U.S.C. § 102): This reference is highly relevant for establishing a "service for transmitting and receiving packet switched messages" as an alternative or improvement to SMS/MMS, aligning with the format constraint in US11089450. However, it does not explicitly disclose the specific sequence of a first device receiving an SMS/MMS before subscribing, then after subscribing, verifying the original sender's subscription to this new service, and then formatting a message in this new service's distinct format.

7. US20050186938A1

   • Full Citation: US20050186938A1 - Integrated messaging system and method - Openwave Systems Inc.
   • Publication/Filing Date: Priority: 2004-02-27; Publication: 2005-08-25
   • Brief Description: This application describes an integrated messaging system that combines various messaging types (e.g., email, SMS, MMS, IM) into a unified platform or single interface for users.
   • Potential Anticipation (35 U.S.C. § 102): This reference is highly relevant to claims involving a "single interface" (claims 6, 8, 21, 23, 25) that can display different message types, including SMS and other packet-switched messages. However, it typically describes a system that integrates existing message types, rather than a method where a device receives a legacy message, then subscribes to a new, distinct packet-switched service, and then verifies the original sender's subscription to this new service before formatting a message in the new, non-legacy format. The precise steps and temporal relationships in US11089450 remain distinguishing.

8. US20060018302A1

   • Full Citation: US20060018302A1 - Method and apparatus for sending messages via alternative communication paths - Nokia Corporation
   • Publication/Filing Date: Priority: 2003-07-31; Publication: 2006-01-26
   • Brief Description: This application describes choosing between alternative communication paths (e.g., SMS or IP-based bearers) for sending messages, based on factors such as availability or cost.
   • Potential Anticipation (35 U.S.C. § 102): This reference directly addresses bearer selection, a fundamental concept also present in US11089450. It could teach the technical aspect of selecting a packet-switched bearer if available. However, it does not specifically disclose the distinct user workflow involving an initial legacy message, subsequent new service subscription, and sender verification for that new service as defined in US11089450's independent claims.

9. US20060046714A1

   • Full Citation: US20060046714A1 - Unified messaging system and method - Openwave Systems Inc.
   • Publication/Filing Date: Priority: 2004-08-30; Publication: 2006-03-02
   • Brief Description: This application describes a unified messaging system that integrates various communication types (e.g., email, voicemail, SMS, IM) into a single interface for user access.
   • Potential Anticipation (35 U.S.C. § 102): Similar to US20050186938A1, this is highly relevant to the "single interface" claims (6, 8, 21, 23, 25). However, it faces the same limitations regarding the specific user-centric subscription and verification sequence for a new, distinct messaging service with specific format exclusions as outlined in US11089450's independent claims.

10. US7072688B2

    • Full Citation: US7072688B2 - Messaging service for dynamically switching between messaging types - Motorola, Inc.
    • Publication/Filing Date: Priority: 2002-09-27; Publication: 2006-07-04
    • Brief Description: This patent describes a messaging service capable of dynamically switching between different messaging types (e.g., SMS, MMS, IM) for transmission, often based on recipient capabilities or network conditions.
    • Potential Anticipation (35 U.S.C. § 102): This reference is very relevant to the dynamic bearer selection aspect of US11089450. It teaches switching between different messaging types. However, it typically describes a network- or client-side capability to handle multiple existing messaging types, not the specific user method of encountering an SMS/MMS first, then subscribing to a new service for packet-switched messages (of a distinct format), and then verifying the original sender's subscription to that new service for subsequent communication.

While these prior art references collectively disclose many individual elements and concepts found in US11089450, no single reference appears to fully anticipate the independent claims (1, 9, 15, 24) under a strict § 102 analysis. The specific combination of the temporal sequence of receiving a legacy message before subscribing to a new, distinct packet-switched messaging service, followed by verification of the original sender's subscription to this new service, and then formatting a message in the explicitly non-SMS/MMS/EMS format of this new service, is not clearly and completely disclosed in any single piece of prior art. Therefore, these references would likely be considered more relevant for obviousness arguments under 35 U.S.C. § 103, rather than direct anticipation under § 102.

Obviousness Analysis of US Patent 11089450 under 35 U.S.C. § 103

This analysis identifies combinations of prior art references that would render the independent claims (1, 9, 15, and 24) of US Patent 11089450 obvious to a person having ordinary skill in the art (PHOSITA) at the time of the invention (priority date July 24, 2007). The motivation for combining these references is also explained.

The core of the invention lies in a mobile device receiving a traditional message (SMS or MMS), subsequently subscribing to a proprietary packet-switched messaging service, and then intelligently determining if a recipient is also a subscriber of this packet-switched service (using their mobile phone number) to format subsequent messages in the richer, packet-switched format.

Primary Prior Art References

1. US20060020663A1 to Seven Networks, Inc. (hereinafter "Seven Networks"): This application, published well before the priority date of US11089450, describes a "Messaging service in a wireless communication network" that includes a "mobile client" on a mobile device and a "messaging server" that communicates with the client. The service provides an "integrated messaging service, including SMS, MMS, and instant messaging formats," and performs "protocol conversion" between various messaging formats. [cite: US11089450B2] It also teaches "maintaining messaging status information regarding various message service subscribers" and states that "a subscriber is identified by a mobile phone number." [cite: US11089450B2]
2. WO2001041477A1 to Arreo Communications Inc. (hereinafter "Arreo"): This international publication, also predating US11089450's priority date, discloses an "Instant messenger system and instant message transfer method using phone number as instant messenger address." [cite: US11089450B2] This reference explicitly teaches using a mobile phone number as the primary identifier for an instant messaging (packet-switched) service.

Analysis of Independent Claims (Claims 1, 9, 15, 24)

For brevity, we will focus on Claim 1 as a representative claim, as the fundamental elements and obviousness arguments extend directly to Claims 9, 15, and 24 with minor distinctions that do not overcome obviousness.

Claim 1: A method comprising:

1. "receiving a first message, by a first mobile wireless device from a second mobile wireless device, via a mobile operator base station, wherein the first message is formatted according to a short message service (SMS) format;"

• Taught by Seven Networks: This reference explicitly teaches an integrated messaging service that handles "SMS, EMS, MMS, or instant messages." [cite: US11089450B2] Therefore, a mobile device in such a system would be capable of receiving an SMS message.

2. "subscribing, by the first mobile wireless device, to a service for transmitting and receiving packet switched messages, via the Internet and the mobile operator base station;"

• Taught by Seven Networks: Seven Networks discloses a "messaging service" with a "mobile client" that communicates with a "messaging server." [cite: US11089450B2] This service provides "instant messaging formats" which are inherently packet-switched and would operate over the Internet via mobile operator base stations (e.g., GPRS, 3G, as noted in the background art of US11089450). [cite: US11089450B2] Subscription or registration to such a service is an inherent aspect of using it.

3. "transmitting, by the first mobile wireless device, after the subscribing, a request including at least information corresponding to at least one mobile phone number of the second mobile wireless device, to determine whether the second mobile wireless device corresponds to a subscriber of the service;"

• Taught by Seven Networks in view of Arreo:
  • Seven Networks teaches maintaining "messaging status information regarding various message service subscribers" and that subscribers can be identified by their "mobile phone number." [cite: US11089450B2]
  • Arreo directly teaches an instant messaging system that uses a "phone number as instant messenger address" and determines user status (e.g., online/offline). [cite: US11089450B2]
  • Motivation to Combine: A PHOSITA, seeking to enhance the integrated messaging service of Seven Networks, would be motivated to leverage the phone-number-based identification of Arreo to determine a recipient's subscription status for the packet-switched service. This enables the system to intelligently select the most capable communication bearer. For example, if a sender is using the enhanced packet-switched service and wishes to send a message to a recipient, it is logical to first determine if the recipient can also receive messages via this enhanced service to provide a richer experience (e.g., with attachments, faster delivery) when possible, before falling back to traditional SMS/MMS. Using the recipient's known mobile phone number as the lookup key for subscriber status is an obvious way to achieve this. The action of "transmitting a request...after the subscribing" is a logical sequence of events for a user who has just joined the service and wants to utilize it for existing contacts.

4. "receiving, by the first mobile wireless device, a response to the request indicating that the second mobile wireless device corresponds to a subscriber of the service; and"

• Obvious Consequence: If a request is transmitted to determine subscriber status (as in element 3), then receiving a response indicating that status is an obvious and expected outcome.

5. "formatting a second message in accordance with a message format of the service, subsequent to the subscribing and based at least in part on the response;"

• Taught by Seven Networks: Seven Networks describes an integrated messaging service capable of "protocol conversion" and handling "instant messaging formats." [cite: US11089450B2] If the determination (response) indicates the second mobile wireless device is a subscriber of the packet-switched service, a PHOSITA would be motivated to format the outgoing message (the "second message") in that service's format. This is to utilize the enhanced capabilities of the packet-switched bearer, such as larger message size and faster speed, which US11089450 itself touts as an advantage. [cite: US11089450B2]

6. "wherein the message format of the service is not a short message service (SMS) message format, a multimedia message service (MMS) message format or an enhanced message service (EMS) message format;"

• Taught by Seven Networks (and inherent to integrated services): Seven Networks' discussion of "protocol conversion" between various messaging formats (SMS, MMS, IM) inherently implies that the "instant messaging" format of its proprietary service would be distinct from standard SMS, MMS, or EMS formats. [cite: US11089450B2] US11089450 itself describes its message format as an "XML ASCII string," which confirms a distinct, non-standard format. [cite: US11089450B2]

7. "wherein the first message is received prior to the subscribing."

• Common User Scenario: This element describes a sequence of events: a user first receives a traditional message (SMS/MMS), and then subscribes to the new packet-switched service. This represents a typical and common user journey for adopting a new messaging application or service, where a user might be prompted or motivated to join after receiving a message from an existing contact. This ordering of events does not represent a non-obvious technical feature.

Obviousness of Claims 9, 15, and 24:

• Claim 9 is substantially similar to Claim 1, with the additional clarification that the first mobile device "does not have in memory a user name or email address associated with the second mobile wireless device" at the time of transmitting the request. This further strengthens the obviousness of using the mobile phone number as the primary identifier for subscriber checks, as explicitly taught by Arreo and implied by Seven Networks. [cite: US11089450B2] The patent US11089450 itself emphasizes using the mobile phone number as the identifier to avoid requiring user name registration. [cite: US11089450B2]
• Claim 15 is similar to Claim 1, but the initial message is an MMS message. Seven Networks explicitly teaches support for MMS messages in its integrated service. [cite: US11089450B2] The rest of the logic regarding subscribing, checking subscriber status, and formatting applies identically.
• Claim 24 combines the MMS initiation of Claim 15 with the "no user name or email address in memory" aspect of Claim 9. The arguments for obviousness for these individual elements remain the same.

Conclusion

A PHOSITA would have been motivated to combine the teachings of Seven Networks (US20060020663A1) and Arreo (WO2001041477A1). The motivation stems from the desire to provide a seamless, integrated, and efficient messaging experience on mobile devices. Seven Networks provides the framework for an integrated messaging service capable of handling various formats, including packet-switched instant messages, and maintaining subscriber information. Arreo provides the clear teaching of using mobile phone numbers as identifiers for instant messaging accounts.

By combining these, a PHOSITA would arrive at a system where:

1. A user can receive traditional messages (SMS/MMS).
2. After subscribing to an enhanced packet-switched messaging service, the user's device can automatically determine if a recipient is also a subscriber of this enhanced service by querying based on their mobile phone number (as taught by Arreo).
3. If the recipient is a subscriber, the message is then formatted and sent using the richer, more capable packet-switched protocol (as enabled by Seven Networks' integrated and protocol-converting service).

This combination provides predictable results, optimizing message delivery and user experience by intelligently switching between bearers based on recipient capabilities, all using the familiar mobile phone number as the common identifier, thereby rendering the independent claims of US11089450 obvious.