A method of transmitting Moving Pictures Experts Group, MPEG, Media Transport, MMT, packets, wherein the method comprises the following steps for reducing a wait time necessary for reproduction of multimedia: assigning media processing unit, MPU, metadata included in a first MPU and a second MPU such that the MPU metadata is transmitted as last of the first MPU and the second MPU; generating the first MPU and the second MPU based on the assignment; generating interval information indicating a transmission time interval for transmitting the first MPU and the second MPU; transmitting the first MPU; transmitting control information within the transmission time interval indicated by the interval information; and transmitting the second MPU based on the interval information, after transmitting the control information, wherein the transmitting of the control information comprises: comparing a length of a signaling message and a preset threshold; and transmitting the signaling message or index information corresponding to the signaling message between the first MPU and the second MPU as the control information, according to whether the length of the signaling message is less than or greater than the preset threshold, wherein the signaling message includes random access information for performing channel access and change operations, and wherein the index information is information used to retrieve the signaling message. assigning media processing unit, MPU, metadata included in a first MPU and a second MPU such that the MPU metadata is transmitted as last of the first MPU and the second MPU; generating the first MPU and the second MPU based on the assignment; generating interval information indicating a transmission time interval for transmitting the first MPU and the second MPU; transmitting the first MPU; transmitting control information within the transmission time interval indicated by the interval information; and transmitting the second MPU based on the interval information, after transmitting the control information, wherein the transmitting of the control information comprises: comparing a length of a signaling message and a preset threshold; and transmitting the signaling message or index information corresponding to the signaling message between the first MPU and the second MPU as the control information, according to whether the length of the signaling message is less than or greater than the preset threshold, wherein the signaling message includes random access information for performing channel access and change operations, and wherein the index information is information used to retrieve the signaling message. comparing a length of a signaling message and a preset threshold; and transmitting the signaling message or index information corresponding to the signaling message between the first MPU and the second MPU as the control information, according to whether the length of the signaling message is less than or greater than the preset threshold, wherein the signaling message includes random access information for performing channel access and change operations, and wherein the index information is information used to retrieve the signaling message.