Provided are a method and an apparatus for transmitting downlink control information in a wireless communication system configured with a plurality of serving cells. The method generates downlink control information scheduling frequency division duplex (FDD) cells by means of FDD frames (DCI_FDD) and downlink control information scheduling time division duplex (TDD) cells by means of TDD frames (DCI_TDD), and transmits the DCI_FDD and the DCI_TDD, wherein parts of the fields of DCI_FDD and DCI_TDD are generated to have equal bit sizes, and if the FDD or TDD cell is used exclusively, then said parts of the fields in the FDD and TDD cells have mutually different bit sizes.

A user equipment has a transmission and reception unit configured to transmit and receive a radio channel to/from a base station via multiple cells configured by carrier aggregation, a simultaneous transmission availability determination unit configured to, in response to an occurrence of an event to transmit an uplink control channel in the multiple cells simultaneously, determine whether the uplink control channel can be simultaneously transmitted in the multiple cells, and a transmission control unit configured to, if the uplink control channel can be simultaneously transmitted in the multiple cells, instruct the transmission and reception unit to transmit the uplink control channel in the multiple cells simultaneously, and if the uplink control channel cannot be simultaneously transmitted in the multiple cells, control transmission of the uplink control channel in accordance with a transmission priority.

Provided are a method for transmitting an ACK/NACK by a terminal configured with a plurality of serving cells, and a terminal using such a method. The method comprises: receiving data from a downlink subframe of a first serving cell; and transmitting the data for the ACK/NACK signal from an uplink subframe of a second serving cell; wherein the uplink subframe is determined in accordance with the ACK/NACK timing of the first serving cell, or the ACK/NACK timing of the second serving cell if the data is received from a downlink subframe of the second serving cell, which is identical to the downlink subframe of the first serving cell.

A first communication device generates and transmits a first physical layer (PHY) data unit as part of a hybrid automatic repeat request (HARQ) session, the first PHY data unit having a first plurality of media access control (MAC) protocol data units (MPDUs) including a first MPDU. The first communication device determines that a second communication device did not acknowledge successfully receiving the first MPDU. The first communication device generates and transmits a second PHY data unit as part of the HARQ session, the second PHY data unit having a second plurality of MPDUs, the second plurality of MPDUs including the first MPDU.

Apparatuses, methods, and systems are disclosed for transmitting a message in response to receiving a message. One apparatus (300) includes a receiver (312) that receives (602) a second message from a second remote unit (200). The second message is transmitted from the second remote unit in response to the second remote unit receiving a first message from a first remote unit. The apparatus (300) includes a transmitter (310) that transmits (604) a third message corresponding to the first message in response to receiving the second message.

Provided are a method for determining the number of hybrid automatic repeat request (HARQ) processes in a carrier aggregated system configured with a plurality of serving cells, and an apparatus using such a method. The method receives data from a downlink subframe of a second serving cell, and transmits an ACK/NACK signal for the data from an uplink subframe of a first serving cell, wherein the first serving cell uses a first-type frame, the second serving cell uses a second-type frame, and the number of HARQ processes in the second serving cell are determined with respect to each subframe comprised in the second-type frame and on the basis of the number of downlink subframes comprised in each section comprising a set number of subframes.

A first communication device generates and transmits a first physical layer (PHY) data unit as part of a hybrid automatic repeat request (HARQ) session, the first PHY data unit having a first plurality of media access control (MAC) protocol data units (MPDUs) including a first MPDU. The first communication device determines that a second communication device did not acknowledge successfully receiving the first MPDU. The first communication device generates and transmits a second PHY data unit as part of the HARQ session, the second PHY data unit having a second plurality of MPDUs, the second plurality of MPDUs including the first MPDU.

A first communication device generates and transmits a first physical layer (PHY) data unit as part of a hybrid automatic repeat request (HARQ) session, the first PHY data unit having a first plurality of media access control (MAC) protocol data units (MPDUs) including a first MPDU. The first communication device determines that a second communication device did not acknowledge successfully receiving the first MPDU. The first communication device generates and transmits a second PHY data unit as part of the HARQ session, the second PHY data unit having a second plurality of MPDUs, the second plurality of MPDUs including the first MPDU.

A method for pre-authenticating a user on the user's mobile device is provided. The method may be implemented on the device. The method may include tracking commonly accessed applications over a pre-determined amount of time. The method may include tracking and storing on the mobile device, application data associated with each commonly accessed application. When a determined current time of day is a pre-determined amount of time prior to the tracked start time of access to a one or more commonly accessed applications, the method may include capturing, autonomously, via each of a plurality of sensors, an attribute associated with the user. The method may further include comparing a value of the attribute captured to a historically stored attribute value. The method may further include verifying and pre-authenticating the user based on the comparing. The method may also include pre-loading the user's mobile device with the commonly accessed application.

Provided are a method for determining the number of hybrid automatic repeat request (HARQ) processes in a carrier aggregated system configured with a plurality of serving cells, and an apparatus using such a method. The method receives data from a downlink subframe of a second serving cell, and transmits an ACK/NACK signal for the data from an uplink subframe of a first serving cell, wherein the first serving cell uses a first-type frame, the second serving cell uses a second-type frame, and the number of HARQ processes in the second serving cell are determined with respect to each subframe comprised in the second-type frame and on the basis of the number of downlink subframes comprised in each section comprising a set number of subframes.