Method for transmitting response information in mobile communications system

A method of performing a random access by a user equipment (UE) in a mobile communication system, the method comprising:

• transmitting a random access preamble to a network;
• monitoring downlink control channel information identified by first type identifier information after transmitting the random access preamble;
• receiving downlink shared channel information including a medium access control packet data unit (MAC PDU) when the downlink control channel information, identified by the first type identifier information, which corresponds to the UE's transmission of the random access preamble, is received, wherein the received MAC PDU comprises a header part and N random access responses, where N is a natural number, the header part includes N subheaders, each of the N subheaders corresponds to each of the random access responses, and wherein each of the N random access responses comprises second type identifier information;
• and
• processing a specific random access response among the N random access responses when the second type identifier information of a specific subheader, which corresponds to the specific random access response, corresponds to the transmitted random access preamble.

A method of controlling random accesses of one or more user equipments (UEs) by a network in a mobile communication system, the method comprising:

• receiving one or more random access preambles from a first set of UEs;
• transmitting downlink control channel information identified by first type identifier information after receiving the random access preambles;
• and
• transmitting downlink shared channel information including a medium access control packet data unit (MAC PDU), wherein, when the first type identifier information of the downlink control channel information identifies that the downlink control channel information corresponds to random access preambles from a second set of UEs, the downlink shared channel information is received by the second set of UEs,
• wherein the transmitted MAC PDU comprises a header part and N random access responses, where N is a natural number, the header part includes N subheaders, and each of the N subheaders corresponds to each of the random access responses,
• wherein each of the N random access responses comprises second type identifier information, and
• wherein a specific random access response among the N random access responses is processed by a specific UE among the second set of UEs when the second type identifier information of a specific subheader, which corresponds to the specific random access response, corresponds to a random access preamble from the specific UE.

A user equipment (UE) for performing a random access in a mobile communication system, the UE comprising:

• a transmitter configured to transmit a random access preamble to a network;
• a receiver configured to receive downlink control channel information and downlink shared channel information;
• and
• a processor configured to control the transmitter and the receiver such that the receiver receives the downlink shared channel information including a medium access control packet data unit (MAC PDU) when the downlink control channel information, identified by first type identifier information which corresponds to the transmission of the random access preamble by the transmitter, is received,
• wherein the received MAC PDU comprises a header part and N random access responses, where N is a natural number, the header part includes N subheaders, each of the N subheaders corresponds to each of the random access responses, and wherein each of the N random access responses comprises second type identifier information, and
• wherein the processor is further configured to process a specific random access response among the N random access responses when the second type identifier information of a specific subheader corresponding to the specific random access response corresponds to the transmitted random access preamble.