NTT DoCoMo has developed the acoustic OFDM (Orthogonal frequency-division multiplexing) technology, which can embed URLs and text data in broadcast music/audio. Consumers’ mobile phones “listen” to the music/audio and extract the embedded URLs/data. About 100 characters can be transmitted in a second. However, to deploy the technology, broadcast stations will need to install a dedicated encoder and mobile phones will have to be enhanced with a decoder mechanism as well.

The technology could be applied at shopping malls and supermarkets where the sound from in-store speakers would deliver information about specials, ads, discount coupons, etc.

A similar technology exists for ultrasonic sound, but DoCoMo’s system uses audible sound that can be transmitted through regular speakers.

Via RFID in Japan.