SMS as interactive channel for portable digital TV receivers

In emerging countries the primary way of communication and entertainment is broadcast TV. Interactive TV content providers, especially the ones aiming handheld devices, can take advantage of SMS (Short Message Service) as a mechanism of returning channel for interacting with a televiewer. On analog TV systems, SMS messages are often used as a form of interaction, but in order to interact with televised programming the televiewer needs, in addition to his TV, a mobile phone so that he can send a text message to the number reported by the TV program. In this scenario two situations may occur: (1) the user may send an incorrect message to the right number, or (2) the user may send the right message to an incorrect number. In both cases he will be charged for the message he sent without knowing he is not interacting with the program which he desires. This problem can be avoided on digital TV systems, with support for interactive channel, mainly in 1-seg transmission dedicated to portable receivers. This paper aims to show the feasibility of using SMS text messaging as an alternative to the interactive channel in the context of digital TV.