A data transmission method to transmit data relating to a first virtual world to a second virtual world, the data transmission method comprising: encoding information relating to the first virtual world into first metadata; and transmitting the first metadata to the second virtual world, wherein the information relating to the first virtual world comprises at least one of information relating to an avatar of the first virtual world and information relating to a virtual object (130, 140) of the first virtual world, wherein a virtual world object data structure includes attributes and characteristics (530, 540, 550) that are shared by the avatar and the virtual object, the method characterized in that the virtual world data structure has a binary representation syntax that defines the characteristics, for the avatar and virtual object, and flags corresponding to the characteristics, wherein the flags express whether the characteristics with respect to respective ones of the avatar and/or the virtual object are used, wherein the encoded information comprises the flags, having a size of 1 bit, and at least one characteristic corresponding to at least one flag having a predetermined logic value of "1", indicating that the corresponding characteristic shall be used, wherein, if the flag has the predetermined logic value of "0", the corresponding characteristic shall not be used,wherein the characteristics corresponding to the flags include: an Identification that describes the identification of the virtual world object, a SoundList that describes the sound effect associated to the virtual world object, a ScentList that describes the scent effect associated to the virtual world object a ControlList that describes controlling of scaling, translation or rotation associated to the virtual world object, an EventList describing the input event associated to the virtual world object, and a BehaviorModelList describing the behavior model associated with the virtual world object, wherein a bit size of the flags in the virtual world object data structure is defined as the number of the flags, and wherein the first metadata comprises the flags and the at least one characteristic corresponding to the at least one flag having the predetermined logic value of "1" and does not comprise characteristics corresponding to respective flags having the predetermined logic value "0". encoding information relating to the first virtual world into first metadata; and transmitting the first metadata to the second virtual world, wherein the information relating to the first virtual world comprises at least one of information relating to an avatar of the first virtual world and information relating to a virtual object (130, 140) of the first virtual world, wherein a virtual world object data structure includes attributes and characteristics (530, 540, 550) that are shared by the avatar and the virtual object, the method characterized in that the virtual world data structure has a binary representation syntax that defines the characteristics, for the avatar and virtual object, and flags corresponding to the characteristics, wherein the flags express whether the characteristics with respect to respective ones of the avatar and/or the virtual object are used, wherein the encoded information comprises the flags, having a size of 1 bit, and at least one characteristic corresponding to at least one flag having a predetermined logic value of "1", indicating that the corresponding characteristic shall be used, wherein, if the flag has the predetermined logic value of "0", the corresponding characteristic shall not be used,wherein the characteristics corresponding to the flags include: an Identification that describes the identification of the virtual world object, a SoundList that describes the sound effect associated to the virtual world object, a ScentList that describes the scent effect associated to the virtual world object a ControlList that describes controlling of scaling, translation or rotation associated to the virtual world object, an EventList describing the input event associated to the virtual world object, and a BehaviorModelList describing the behavior model associated with the virtual world object, an Identification that describes the identification of the virtual world object, a SoundList that describes the sound effect associated to the virtual world object, a ScentList that describes the scent effect associated to the virtual world object a ControlList that describes controlling of scaling, translation or rotation associated to the virtual world object, an EventList describing the input event associated to the virtual world object, and a BehaviorModelList describing the behavior model associated with the virtual world object, wherein a bit size of the flags in the virtual world object data structure is defined as the number of the flags, and wherein the first metadata comprises the flags and the at least one characteristic corresponding to the at least one flag having the predetermined logic value of "1" and does not comprise characteristics corresponding to respective flags having the predetermined logic value "0".