A communication method and a system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT) are provided. The system may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The method includes receiving, from a base station, scheduling information for a first uplink packet transmission in a first time slot, determining whether the first uplink packet transmission in the first time slot is restricted based on information corresponding to a second uplink packet transmission in the first time slot of another terminal, and if the first uplink packet transmission in the first time slot is restricted, skipping the first uplink packet transmission in a first time slot.

A method of configuring downlink timings and transmitting a random access response message is provided for a random access procedure in a Long Term Evolution (LTE) system supporting carrier aggregation. The method for adjusting timing of a terminal in a wireless communication system supporting carrier aggregation of at least one carrier includes transmitting a Random Access Preamble to a base station, and receiving a Random Access Response with a Timing Advance Command (TAC) for commanding uplink timing adjustment from the base station, wherein the Random Access Response comprises information indicating a Timing Advance Group (TAG) to which the TAC is applied.

The present disclosure provides a grant free state for user equipment, for example a machine type communication (MTC) UE. There is provided a method for transitioning a state of a User Equipment (UE). The method includes determining, by the UE, if data is to be sent and transitioning, by the UE, to a grant free state when no data is to be sent, wherein transitioning to the grant free state includes receiving a grant free identifier (GF-ID). In some embodiments, the method further includes in accordance with a determination that an amount of data to be sent is below a threshold, transmitting, by the UE, the data together with the GF-ID. In addition, user equipment and base transceiver stations are provided each of which include a processor and memory having instructions stored thereon, which when executed by the processor configure the respective UE or BTS to perform the respective methods.

Disclosed is a radio communication system in which a base station device and a terminal device communicate with each other, and the terminal device performs a random access procedure. The base station device notifies the terminal device of random access common configuration information including the number of repetitions for each level, information indicating a relationship between group information of random access preambles and the level, and the number of attempts of preamble transmission for each level. A MAC layer in the terminal device performs processing of increasing the level in a case that a first counter exceeds the number of attempts of transmission corresponding to the level.

This invention discloses a method for controlling a wireless communication device to reduce the number of retry times of data packets during transmission. The method includes steps of: using a first packet length to generate and transmit data packets; counting retry times of data packets in a predetermined time period and generating a result accordingly; and using a second packet length smaller than said first packet length to generate and transmit data packets when said result is greater than a predetermined value.

A wireless device transmit a first message comprising a first preamble and a first transport block. The first transport block comprises a contention resolution identifier of the wireless device. The wireless device receive a first random access response to the first message. The first random access response comprises the contention resolution identifier. The wireless device starts a first time window in response to receiving the first random access response. The wireless device monitor, during the first time window, a downlink channel for a second random access response to the first message. The wireless device determines a failure to receive the second random access response during the first time window. The wireless device transmits a second message comprising a second preamble in response to the failure.

Provided is a wireless communication terminal that wirelessly communicates with a base wireless communication terminal. The wireless communication terminal includes a transceiver, and a processor. The processor is configured to set an integer selected from a range of 0 to a value equal to or smaller than an OFDMA Contention Window (OCW) as a counter for random access, receive a trigger frame for triggering random access using one or more resource units (RUs) allocated for the random access from the base wireless communication terminal using the transceiver, decrement a value of the counter based on the one or more RUs allocated for the random access, randomly select one RU based on the one or more RUs allocated for the random access when the value of the counter is 0 or reaches 0, and attempt transmission to the base wireless communication terminal using the selected RU.

Some techniques and apparatuses described herein provide an indication of a result of decoding a two-step random access channel (RACH) message and an action to be performed by a user equipment (UE). For example, some techniques and apparatuses described herein may provide the indication using a UE contention resolution identity-based approach, wherein the contention resolution identity of the UE may be provided in a random access response. Some techniques and apparatuses described herein may use a fallback indicator that indicates the result of decoding and/or the action to be performed. Some techniques and apparatuses described herein may use a random access response (RAR) subheader that selectively omits a random access preamble identifier based at least in part on the result of decoding and/or the action to be performed.

Example methods and apparatus for implementing collision detection in data transmission are described. One example method includes sending a data packet including collision detection information to a receive end, where the collision detection information is used by the receive end to perform collision detection on the data packet. A status indication message sent by the receive end is received by the receive end when sending the data packet. The receive end parses the status indication message. If the status indication message includes collision information, the receive end perform retransmission of the data packet.

A wireless device registers with a first PLMN having a first PLMN identity. A first plurality of RA procedures is performed while registered with the first PLMN. First information related to the first plurality of RA procedures is stored. The wireless device registers with a second PLMN having a second PLMN identity different than the first PLMN identity after registering with the first PLMN and after performing the first plurality of RA procedures. The first information is discarded responsive to registering with the second PLMN. A second plurality of RA procedures is performed while registered with the second PLMN. Second information related to the second plurality of RA procedures is stored. An information message is transmitted to the second PLMN. The information message includes a plurality of RACH reports corresponding to the second plurality of RA procedures based on the second information.