A wireless device receives a control message configuring cell groups comprising a first cell group and a second cell group. The wireless device receives a control command causing the wireless device to transmit a random access preamble on a secondary cell in the secondary cell group. Transmission timing of the random access preamble is determined, at least in part, employing uplink subframe transmission timing of the primary cell or a stored timing advance value.

The present disclosure discloses a bandwidth part switching method, a terminal device, and a computer storage medium. The method includes: obtaining a timer; and determining, based on the timer, whether to switch from a currently activated first bandwidth part (BWP) to a second BWP, where the first BWP is not the second BWP.

A user equipment, a base station, and a method for determining search space sets for PDCCH monitoring. The UE includes a receiver and a processor and is configured to receive a configuration for search space sets. The configuration includes a first group of search space sets, a second group of search space sets, a first group index for the first group of search space sets, and a second group index for the second group of search space sets. The UE is also configured to determine an indication corresponding to either the first group index or the second group index, and to receive, based on the indication, physical downlink control channels (PDCCHs) according to either the first group of search space sets or the second group of search space sets.

A method performed by a communication device comprises identifying a long transmission time interval (TTI) transport block size from a set of long TTI transport block sizes used for transport block transmission within a long TTI. The method further comprises determining a short TTI transport block size, used for transport block transmission within a short TTI, by downscaling the long TTI transport block size based on a relation between a number of symbols in the short TTI and a number of symbols in the long TTI that is greater than the number of symbols in the short TTI.

A communications method and device for multi-carrier aggregation, where the method includes: grouping by a base station, N serving cells into K cell groups, where N is an integer greater than zero, and K is an integer less than N, sending, by the base station, a cell grouping message to user equipment (UE), where the cell grouping message indicates that the N serving cells are grouped into the K cell groups, and communicating, by the base station, with the UE according to the K cell groups. Hence, signaling overheads can be reduced.

The present specification relates to a method for receiving dormant bandwidth part (BWP) configuration information, performed by a terminal in a wireless communication system, the method comprising: receiving the dormant BWP configuration information from a base station, wherein the dormant BWP configuration information is information about a downlink BWP used as the dormant BWP among at least one downlink BWP set to the terminal; receiving, from the base station, downlink control information (DCI) notifying activation of the dormant BWP; and stopping monitoring of a physical downlink control channel (PDCCH) on the dormant BWP, wherein a BWP inactivity timer is not used on the basis of the activation of the dormant BWP, and the BWP inactivity timer is a timer for a transition to a default BWP.

Methods, systems, and devices for wireless communication are described. Different transmission time interval (TTI) durations may be supported and configured to coexist with one another. A set of TTIs with a relatively short duration may overlap in time with longer duration TTIs. Boundaries of TTIs with a relatively short duration may be configured to align with boundaries of relatively longer duration TTIs. For example, TTIs that are a Long Term Evolution (LTE) subframe, an LTE slot, and a duration of two LTE symbol periods may be supported. Two-symbol period TTIs may align with or be embedded within slot-duration TTIs, which, in turn, may align with or be embedded within a subframe. In some examples, one or more symbol periods of a subframe may be designated as a gap between two-symbol TTIs within the subframe, or such symbols may be merged with a two-symbol TTI within the subframe.

A method for transmitting and receiving data in a wireless communication system and an apparatus for the method are disclosed. More specifically, a method for transmitting downlink data in a wireless communication system comprises transmitting, by an eNB, first downlink data through a physical downlink shared channel (PDSCH) region according to a radio frame structure based on a first transmission time interval (TTI); and transmitting, by the eNB, second downlink data through a short PDSCH (sPDSCH) region according to a radio frame structure based on a second TTI, wherein downlink control information (DCI) related to the second downlink data is transmitted through a physical downlink control channel (PDCCH) or a short PDCCH (sPDCCH).

A wireless relay wirelessly receives user data from User Equipment (UE) using a UE uplink Carrier Aggregation (CA) configuration. The wireless relay wirelessly transfers the user data using a relay uplink. The wireless relay determines available Power Headroom (PHR) for the relay uplink and translates the available PHR into a new UE uplink CA configuration. The wireless relay wirelessly receives additional user data from the UE using the new UE uplink CA configuration.

Method and apparatus for supporting a partial sub-frame data transmission in LTE systems. The transmitting device performs a channel assessment in a previous sub-frame in an unlicensed carrier (S110). After a successful channel assessment, the transmitting device starts a data transmission (S120). The transmitting device transmits a control message for indicating the data transmission in (E)PDCCH (S140). The control message may include the starting time of the data transmission and/or at least one transmission characteristic in the previous sub-frame. The transmission device may transmit an initial control message for indicating a potential data transmission being started in the sub-frame in which the initial control message is transmitting. Method and apparatus enable (E)CCA to take place at any time, and data transmission to start earlier than the next sub-frame boundary after a successful completion of (E)CCA, thus improving the data transmission capacity, especially in circumstances when the maximum length of transmission is constrained.