Acoustic Data Transmission to Ad-hoc Mobile Phone Arrays
In show environments like cinemas, theaters, music concerts, entertainment theme parks, or at sport stadiums, offering a reliable communication channel from the show event (movie, concert) towards mobile phones located in the audience enables interesting new applications. For example, events in a movie can trigger additional and assisting information to appear on a phone’s display. This is particularly attractive when there is no need for a wireless infrastructure. Avoiding the need for a dedicated wireless infrastructure, the movie (or show) can directly interact with phones in the audience, independently of the local resources. Wirelessly communicating data from a movie to mobile phones in a cinema can be realized by using the cinema audio system and multiple loudspeakers. The system introduced in this project addresses the problem of how to offer a larger throughput per mobile phone over the acoustic channel, with higher reliability. We let multiple phones observe independently the incoming audio signals from loudspeakers. The phones group together and connect with each other via radio communication, so that they can jointly process the received data messages. Phones at different locations often observe different audio channel error characteristics, which can be exploited during error handling (spatial diversity), once they are connected with each other.