Wireless Emergency Alert Retry Using Targeted Unicast Delivery

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Solution Overview

Problem

The Wireless Emergency Alert (WEA) system faces challenges in confirming delivery of messages to mobile devices due to network coverage issues, device settings, and interference, which can lead to critical alerts being missed, and existing methods for retrying delivery are inaccurate and inefficient.

Innovation Solution

A method involving a cellular network operator to identify non-receiving endpoint devices through peer-to-peer communications, broadcasting a discovery message indicating WEA receipt, and transmitting targeted unicast messages with the alert content to ensure delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If WEA messages are broadcast to all devices in an area, then message coverage is improved, but delivery confirmation accuracy deteriorates because there is no mechanism to confirm which devices actually received the message

Engineering Contradiction:

Improvemessage coverage areaVSAvoiddelivery confirmation accuracy

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where endpoint devices that receive WEA messages transmit confirmation signals back to the network. The network then identifies devices that did not send confirmations and targets them for unicast retransmission, creating a closed-loop system that improves delivery confirmation accuracy while maintaining broad coverage

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent introduces an intermediary discovery message mechanism that facilitates indirect confirmation of message receipt. Devices broadcast discovery messages indicating whether they received the WEA alert, allowing the network to infer receipt status without direct acknowledgment from each device, thus improving accuracy while preserving broadcast efficiency

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If unicast messages are sent to all devices to ensure delivery, then delivery reliability is improved, but network resource consumption deteriorates due to excessive messaging overhead

Engineering Contradiction:

Improvemessage delivery reliabilityVSAvoidnetwork resource consumption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies local quality by differentiating message delivery approaches based on device-specific receipt status. Instead of uniform unicast to all devices, the system identifies individual devices that missed the broadcast and targets only those with unicast messages, optimizing network resource consumption while maintaining high delivery reliability

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses partial action by sending unicast messages only to the subset of devices that failed to receive the broadcast, rather than excessive action of sending to all devices. This selective approach reduces network overhead while ensuring reliable delivery to all intended recipients

Inventive Principle:

Principle #16Partial or excessive action

3Loss of information

If the WEA message size is increased to include more information, then information completeness is improved, but device compatibility deteriorates due to limited display capabilities of mobile devices

Engineering Contradiction:

Improvealert information completenessVSAvoiddevice compatibility

Core Design Contradiction:

Loss of informationVSAdaptability or versatility

Solution Approach 1:

The patent segments alert information into two parts: a condensed WEA message within the 90-character broadcast limit for broad device compatibility, and extended information delivered via unicast messages to devices that received the broadcast. This segmentation allows information completeness to be improved without sacrificing device compatibility

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent adds another dimension to information delivery by using two different communication channels (broadcast and unicast) with different capacity characteristics. The broadcast channel carries condensed information compatible with all devices, while the unicast channel provides extended information to capable devices, effectively expanding the information dimension without compromising compatibility

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS12520116B2Wireless emergency alert message failure notification and targeted retry

Publication Date: 2026.01.06 AT&T INTELLECTUAL PROPERTY I L P

AI summary

A method, computer-readable medium, and apparatus for transmitting a unicast message comprising a message content of a wireless emergency alert message to an endpoint device that did not receive the wireless emergency alert message are disclosed. For example, a processing system of a cellular network including at least one processor may receive a request to broadcast a wireless emergency alert message, where the request comprises an alert area and a message content, broadcast the wireless emergency alert message in the alert area, where the wireless emergency alert message includes the message content, obtain a notification that a first endpoint device did not receive the wireless emergency alert message, and transmit a unicast message comprising the message content to the first endpoint device.