Patent attributes
Cellular communication networks may be configured to broadcast wireless emergency alert (WEA) messages to multiple receiving communication devices. A communication device has physical-layer components, such as a modem subsystem, that receive broadcast alert messages. The modem subsystem uses a cache to record received alert messages and references the cache to perform duplication checking for newly received messages. Newly received messages that are not duplicates are provided to application-layer software for further processing. The application-layer software notifies a device user of the alert message if the alert message satisfies certain criteria. In addition, the application-layer detects changes in device properties that could potentially affect the criteria and in response causes the cache of the modem subsystem to be cleared so that the modem subsystem will not declare a subsequently received alert message to be a duplicate.