A navigation method and apparatus of a mobile terminal displays only a particular point of interest existing by the roadside of a pre-set route when the POI is selected by the user, to thereby provide the user-selected POI without changing the route. Thus, there are provided a device and a method for converting a code obtained y encoding audio by a certain method into a code decodable by the other method with a low calculation amount. This can specify the collision position quickly and facilitate the manufacturing of the apparatus. Server processes typically run as a single instance to support all users, and are organized into server collections.