This work answers the question : is it possible to transmit a sms using phones as relay in a big city such as Mexico City? We defined a simple transport protocol to transmit sms from a source to a destination. This protocol does not need routing, it is based on locality of sms, the density of phones in Mexico City and mobility of phone users. We studied a mobile dataset including 8 millions users living in Mexico city. This gave use a precise estimation of the average transmission time and the global performances of our approach. After 30 minutes, half of the sms were delivered successfully to destination.