KR20200069207A - Method and apparatus for transmitting user data through random access response message in mobile communication system - Google Patents

Abstract

The present disclosure relates to a communication technique for integrating a 5G communication system with IoT technology to support a higher data rate after a 4G system, and a system thereof. The disclosure is based on 5G communication technology and IoT-related technologies, such as intelligent services (for example, smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, security and safety related services, etc.). The present invention discloses a method and an apparatus for efficiently transmitting user data through a random access response message in a mobile communication system.

Description

Method and device for transmitting user data through a random access response message in a mobile communication system {METHOD AND APPARATUS FOR TRANSMITTING USER DATA THROUGH RANDOM ACCESS RESPONSE MESSAGE IN MOBILE COMMUNICATION SYSTEM}

The present invention relates to a method and apparatus for efficiently transmitting user data through a random access response message in a mobile communication system.

Efforts have been made to develop an improved 5G communication system or a pre-5G communication system to meet the increasing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, the 5G communication system or the pre-5G communication system is called a 4G network (Beyond 4G Network) communication system or an LTE system (Post LTE) or later system. To achieve high data rates, 5G communication systems are contemplated for implementation in the ultra-high frequency (mmWave) band (eg, 60 gigabit (60 GHz) band). In order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, in 5G communication systems, beamforming, massive array multiple input/output (massive MIMO), full dimensional multiple input/output (FD-MIMO) ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, to improve the network of the system, in the 5G communication system, the evolved small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network , Device to Device communication (D2D), wireless backhaul, mobile network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation Technology development is being conducted. In addition, in the 5G system, advanced coding modulation (Advanced Coding Modulation (ACM)), Hybrid FSK and QAM Modulation (FQAM) and SSC (Sliding Window Superposition Coding), SWB (Filter Bank Multi Carrier), and NOMA, are advanced access technologies. (non orthogonal multiple access), and SCMA (sparse code multiple access) are being developed.

Meanwhile, the Internet is evolving from a human-centered connection network in which humans generate and consume information, to an Internet of Things (IoT) network that exchanges information between distributed components such as objects. Internet of Everything (IoE) technology, in which big data processing technology, etc. through connection to a cloud server, etc. is combined with IoT technology is also emerging. In order to implement IoT, technical elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, a sensor network for connection between objects, a machine to machine (Machine to Machine) , M2M), MTC (Machine Type Communication) and other technologies are being studied. In an IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects to create new values in human life may be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, high-tech medical service through convergence and complex between existing IT (information technology) technology and various industries. It can be applied to.

Accordingly, various attempts have been made to apply a 5G communication system to an IoT network. For example, 5G communication technology such as sensor network, machine to machine (M2M), and MTC (Machine Type Communication) is implemented by techniques such as beamforming, MIMO, and array antenna. It is. It may be said that the application of cloud radio access network (cloud RAN) as the big data processing technology described above is an example of fusion of 5G technology and IoT technology.

With the recent development of mobile communication systems, there is a need for a method and apparatus for efficiently transmitting user data through a random access response message. In addition, there is a need for a method and apparatus for efficiently performing cell reselection of a terminal according to the same frequency priority in a mobile communication system.

The present invention proposes a method and apparatus for efficiently transmitting user data through a random access response message in a mobile communication system.

In addition, the present invention proposes a method and apparatus for efficiently performing cell reselection of a terminal according to the same frequency priority in a mobile communication system.

The present invention for solving the above problems is a control signal processing method in a wireless communication system, comprising: receiving a first control signal transmitted from a base station; Processing the received first control signal; And transmitting the second control signal generated based on the processing to the base station.

According to an embodiment of the present invention, user data can be efficiently transmitted through a random access response message in a mobile communication system.

According to another embodiment of the present invention, it is possible to efficiently perform cell reselection of a terminal according to the same frequency priority in a mobile communication system.

1A is a diagram showing the structure of an LTE system to which the present invention is applied.
1B is a diagram showing a radio protocol structure in an LTE system to which the present invention is applied.
1C is a diagram for explaining a random access process in the present invention.
1D is a flowchart of a process of receiving and transmitting user data in a random access response message in the present invention.
1E is a configuration diagram of a random access response message that does not contain user data in the present invention.
1F is a block diagram of a random access response message for storing user data in the present invention.
1G is a flowchart of terminal operation in the present invention.
1H is a flowchart of the operation of a base station in the present invention.
1I is a flowchart of the MME operation in the present invention.
1J is a block diagram showing the internal structure of a terminal to which the present invention is applied.
1K is a block diagram showing the configuration of a base station according to the present invention.
1L is a configuration diagram of a random access response message accommodating an RAR subheader having an L field and an RAR having an L size in the present invention.
1m is a configuration diagram of an RAR subheader including an L field in the present invention.
1n is a configuration diagram of a MAC RAR including a NAS container in the present invention.
Figure 1o is a flow chart of the terminal operation in the present invention.
1p is a flow chart of the base station operation in the present invention.
2A is a diagram illustrating the structure of an LTE system according to an embodiment of the present invention.
2B is a diagram illustrating a radio protocol structure in an LTE system according to an embodiment of the present invention.
2C is a diagram illustrating the structure of a next-generation mobile communication system according to an embodiment of the present invention.
2D is a diagram illustrating a radio protocol structure of a next generation mobile communication system according to an embodiment of the present invention.
Figure 2e is a procedure according to an embodiment of the present invention, the base station releases the connection of the terminal, the terminal to switch from the RRC connected mode (RRC connected mode) to the RRC idle mode (RRC idle mode), the terminal is connected to the base station It is a diagram for explaining a procedure for switching from RRC idle mode to RRC connected mode by setting.
Figure 2f is a procedure according to an embodiment of the present invention, the base station releases the connection of the terminal, and the terminal switches from the RRC connected mode (RRC connected mode) to the RRC inactive mode (RRC inactive mode) and the terminal connects to the base station It is a diagram for explaining a procedure for switching from RRC inactive mode to RRC connected mode by setting.
2G is a diagram illustrating a process of reselecting a cell when the UE is in an RRC idle mode or an RRC inactive mode, according to an embodiment of the present invention.
FIG. 2H illustrates a process of reselecting an intra-frequency/inter-frequency cell having the same priority as the frequency of a serving cell when the UE is in RRC idle mode or RRC inactive mode, according to an embodiment of the present invention. It is one drawing.
2i is a block diagram showing the internal structure of a terminal according to an embodiment of the present invention.
2J is a block diagram showing the configuration of an NR base station according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with the accompanying drawings. In addition, in the description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or practice. Therefore, the definition should be made based on the contents throughout this specification.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains. It is provided to fully inform the holder of the scope of the invention, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same components throughout the specification.

<First Example>

In the following description of the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted. Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The present invention is prepared based on the LTE system, but is also applied to other mobile communication systems such as NR, which is a next-generation mobile communication system. For example, in the present invention, eNB in LTE corresponds to gNB in NR and MME in LTE to AMF in NR.

1A is a diagram showing the structure of an LTE system to which the present invention is applied.

Referring to Figure 1a, as shown, the radio access network of the LTE system is a next-generation base station (Evolved Node B, hereinafter referred to as ENB, Node B or base station) (1a-05, 1a-10, 1a-15, 1a-20) It consists of MME (1a-25, Mobility Management Entity) and S-GW (1a-30, Serving-Gateway). User equipment (User Equipment, UE or UE) 1a-35 accesses an external network through ENBs 1a-05 to 1a-20 and S-GW 1a-30.

In FIG. 1A, ENBs 1a-05 to 1a-20 correspond to existing Node Bs of the UMTS system. ENB is connected to the UE (1a-35) by a radio channel and performs a more complicated role than the existing Node B. In the LTE system, all user traffic, including real-time services such as VoIP (Voice over IP) through the Internet protocol, is serviced through a shared channel, so status information such as buffer status of UEs, available transmission power status, channel status, etc. It is necessary to have a device that collects and schedules scheduling, and ENB (1a-05 to 1a-20) is responsible for this. One ENB usually controls multiple cells. For example, in order to realize a transmission speed of 100 Mbps, the LTE system uses, for example, an orthogonal frequency division multiplexing (OFDM) in a 20 MHz bandwidth as a radio access technology. In addition, an adaptive modulation & coding (hereinafter referred to as AMC) method is applied to determine a modulation scheme and a channel coding rate according to a channel state of a terminal. S-GW (1a-30) is a device that provides a data bearer, and creates or removes a data bearer under the control of the MME (1a-25). MME is a device that is responsible for various control functions as well as mobility management functions for terminals, and is connected to multiple base stations.

1B is a diagram showing a radio protocol structure in an LTE system to which the present invention is applied.

Referring to Figure 1b, the radio protocol of the LTE system is the PDCP (Packet Data Convergence Protocol 1b-05, 1b-40), RLC (Radio Link Control 1b-10, 1b-35), MAC (Medium Access) in the terminal and the ENB, respectively. Control 1b-15, 1b-30). PDCP (Packet Data Convergence Protocol) (1b-05, 1b-40) is responsible for operations such as IP header compression/restore, and radio link control (hereinafter referred to as RLC) (1b-10, 1b-35) ) Reconfigures the PDCP packet data unit (PDU) to an appropriate size to perform ARQ operation. MAC (1b-15, 1b-30) is connected to several RLC layer devices configured in one terminal, and performs an operation of multiplexing RLC PDUs to MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The physical layers 1b-20 and 1b-25 channel-code and modulate the upper layer data, make OFDM symbols, and transmit them on a wireless channel, or demodulate and channel decode the OFDM symbols received through the wireless channels and deliver them to the upper layer. Do the action.

1C is a diagram for explaining a random access process in the present invention.

Random access is performed when matching uplink synchronization or transmitting data to a network. In more detail, it can be performed when switching from standby mode to connected mode, performing RRC re-establishment, performing handover, or starting uplink and downlink data. When the terminal 1c-05 receives a dedicated preamble from the base station 1c-10, the terminal 1c-05 applies the preamble and transmits the preamble. Otherwise, the terminal selects one of the two preamble groups and selects a preamble belonging to the selected group. The groups are referred to as group A and group B. If the channel quality state is better than a certain threshold, and the size of msg 3 is greater than a certain threshold, the preamble belonging to group B is selected, otherwise the preamble belonging to group A is selected. If the preamble is transmitted in the nth subframe (1c-15), a RAR (Random Access Response) window starts from the n+3th subframe and monitors whether RAR is transmitted within the window time interval ( 1c-20). The scheduling information of the RAR is indicated by RA-RNTI of the PDCCH. The RA-RNTI is derived by using a radio resource location on a time and frequency axis used to transmit the preamble. The RAR includes Timing Advance Command, UL grant, and temporary C-RNTI. If the RAR is successfully received in the RAR window, msg 3 is transmitted using the UL grant included in the RAR (1c-25). Msg3 includes different information according to the purpose of the random access. The following table is an example of information carried in msg 3.

[Table 1] Example of information included in msg3

Msg3 is transmitted in the n+6th subframe if RAR is received in the nth subframe. From Msg3, HARQ is applied. After transmitting Msg3, the terminal drives a specific timer, and monitors a Contention Resolution (CR) message until the timer expires (1c-30). In addition to the CR MAC CE, the CR message includes an RRC Connection Setup or RRC Connection Reestablishment message according to a random access purpose.

The present invention does not switch the standby mode (RRC_Idle) or the inactive mode (RRC_Inactive) terminal to the connection mode (RRC_Connected) in the mobile communication system, and transmits and receives a user data of a predetermined small size during a random access process with the base station. Suggest. In the present invention, the above technology is referred to as EDT (Early Data Transmission). In particular, the present invention proposes a method for a base station to transmit user data to a mobile terminal (Mobile Terminated-initiated, MT-initiated) using the EDT technology. In the present invention, the downlink transmission is referred to as DL EDT (Downlink Early Data Transmission). In the DL EDT, various options may exist depending on whether the user data is received and transmitted in a paging message or RAR or msg 4, and the present invention is characterized in that the user data is received and transmitted in the RAR. The details of the present invention are described based on the LTE system, but the technology of the present invention is also applicable to the NR system. For example, eNB corresponds to gNB and MME corresponds to AMF.

1D is a flowchart of a process of receiving and transmitting user data in a random access response message in the present invention.

Wireless devices belonging to Machine Type Communication (MTC) or Internet of Things (IoT) need to send and receive user data of a very small size. For example, in order to turn on or off some functions of the wireless device, it is necessary to transmit and receive a few bits of data. The size of the random access response message (RAR) is very limited, but there is no problem in transmitting the data of the few bits, and the time required to transmit and receive user data can be reduced by using the RAR.

The terminal 1d-05 checks whether the base station supports the EDT through the system information broadcast by the base station 1d-10 (1d-20). Specifically, the base station may set whether to support DL EDT or DL EDT using RAR in system information. In addition, the base station provides dedicated preambles used for DL EDT operation using RAR as system information.

The terminal is switched to a connection mode through a connection process with the base station (1d-25). The base station requests terminal capability information from the terminal using a predetermined RRC message (1d-30). The terminal reports its capability information to the base station (1d-35), and the capability information includes an indicator indicating whether the terminal supports DL EDT using RAR. The base station obtaining the capability information from the terminal transmits the information to the MME (1d-40).

In the MME, paging is triggered to transmit user data of a small size that can be accommodated in the RAR to the terminal (1d-45). The MME determines whether the UE supports DL EDT using a paging message and whether the user data can be stored in the RAR. The amount of user data that can be stored in the RAR may be previously reported or received from the base station, or a fixed value may be predefined. If the two conditions are satisfied, the MME transmits the small-sized user data together while transmitting paging to the base station (1d-50). In addition, it may indicate that the user data is transmitted through the RAR.

Upon receiving the paging and user data, the base station transmits a PDCCH with a separate RNTI indicating that it is a paging message composed only of a paging record of a user related to DL EDT to the UE (1d-55). Alternatively, the PDCCH to which the existing P-RNTI is applied can be transmitted to the terminal. The base station transmits a paging message containing predetermined information to the terminal (1d-60). Indicators and dedicated preamble information indicating this are stored in the paging record of the terminal that needs to receive the user data stored in the RAR. One or more paging records may be associated with the RAR-based DL EDT. Since the terminal that needs to receive the user data stored in the RAR decodes all the received paging messages, it is possible to know whether another user or another terminal should receive the user data through the RAR.

The terminal that needs to receive the user data stored in the RAR transmits the provided dedicated preamble to the base station (1d-65).

The base station transmits the RAR containing the MAC RAR corresponding to the dedicated preamble (1d-70). Usually, one RAR can provide MAC RAR for a plurality of terminals. User data for a plurality of terminals can also be stored in one RAR, and user data for each terminal is stored in a NAS container of a corresponding MAC SDU. Therefore, a plurality of NAS containers storing user data may exist in one RAR. The reason for using the NAS container is to apply NAS security. The DCI corresponding to the RA-RNTI transmitted on the PDCCH may include information on the MAC SDU including the NAS container in the RAR. For example, the number information of the MAC SDU or NAS container stored in the RAR (the same as the number of subheaders related to the RAR based DL EDT) may be included in the DCI. The information is used for the purpose of confirming the location of the MAC SDU in the RAR. Alternatively, it can be limited that there is only one MAC SDU in one RAR.

If there is uplink user data to respond to downlink user data stored in the RAR or if an ACK/NACK purpose is required (1d-75), the terminal uses the msg3 message to use the uplink user data. Transmit, or transmit a predetermined message for ACK/NACK purposes (1d-80). The msg3 is transmitted using UL grant information provided by the RAR.

The base station forwards the received uplink user data or ACK/NACK information to the MME (1d-85).

1E is a configuration diagram of a random access response message that does not contain user data in the present invention.

Figure 1e (a) is an example of the configuration of the RAR. The RAR consists of one MAC header and one or more MAC RARs. Optional padding can be added. The size of the MAC header is variable, and is composed of one or more MAC PDU subheaders. Each MAC PDU subheader (that is, the E/T/RAPID MACA subheader) except for the BI subheader (ie, E/T/R/R/BI subheader) corresponds to one MAC RAR. The BI subheader is optionally present in the RAR and is located at the head of the MAC header.

1E (b) is a configuration diagram of an E/T/RAPID MAC subheader. The E field indicates whether another subheader exists after the subheader. If the value is 1, then another subheader is present, but if it is 0, then MAC RAR or padding is present. The T field indicates whether the subheader is an E/T/RAPID MAC subheader or an E/T/R/R/BI MAC subheader. If the value is 0, it is the E/T/R/R/BI MAC subheader, and if it is 1, it is the E/T/RAPID MAC subheader. The RAPID field is the ID of the random access preamble, and is used to indicate the preamble that has been transmitted.

1E (c) is a configuration diagram of an E/T/R/R/BI MAC subheader. R is a reserved bit. BI indicates the backoff value. This information is used to derive the waiting time to wait until the retry when the random access is not successfully completed.

1E (d) is a configuration diagram of a MAC RAR. Timing Advance Command information indicates transmission timing information to be adjusted for uplink synchronization. UL grant is scheduling information of msg3. Temporary C-RNTI is used to indicate the DCI corresponding to msg4 in the PDCCH, and can be converted to C-RNTI after random access.

1F is a block diagram of a random access response message for storing user data in the present invention.

A first embodiment of the configuration diagram of a random access response message for storing user data, in FIG. 1F (a), a subheader 1f-05 including a RAPID indicating a preamble associated with a RAR-based DL EDT is one MAC. It corresponds to RAR (1f-10) and one MAC SDU (1f-15). The subheader is always located behind other subheaders not related to the RAR based DL EDT in the MAC header. The MAC RAR and MAC SDU mapped to the subheader are adjacent to each other, and are always located behind the MAC RAR mapped to other subheaders not related to the RAR-based DL EDT. However, it is located in front of the padding. The reason behind placing the MAC SDU in the MAC payload is to minimize the effect on the terminal that does not support the DL EDT. In one RAR, a plurality of subheaders including a RAPID indicating a preamble associated with a RAR-based DL EDT, and a combination of one MAC RAR and one MAC SDU corresponding thereto may exist. In the MAC SDU, a NAS container containing user data exists. There may be a predetermined RRC message accommodating the NAS container. The RRC message belongs to SRB0. The RRC message includes S-TMSI information and establishment cause information of the terminal that needs to receive the user data, in addition to the NAS container. The cause information is used to indicate what kind of data the user data is. For example, it may indicate whether it is MT data or delay tolerant access.

A second embodiment of the configuration diagram of a random access response message for storing user data, in FIG. 1F (b), a subheader 1f-20 including RAPID indicating a preamble associated with a RAR-based DL EDT is one MAC. It corresponds to RAR (1f-25) and one MAC SDU (1f-30). The subheader is located behind the BI subheader in the MAC header, and there is no order restriction with other E/T/RAPID MAC subheaders. The MAC RAR and MAC SDU mapped to the subheader need not be adjacent to each other. The location of the mapped MAC RAR in the MAC payload is the same as the location of the subheader in the MAC header. However, the mapped MAC SDU is always located after another MAC RAR. When there are a plurality of MAC SDUs, the order follows the order of the mapped subheaders in the MAC header. However, it is located in front of the padding. The reason behind placing the MAC SDU in the MAC payload is to minimize the effect on the terminal that does not support the DL EDT. In one RAR, a plurality of subheaders including a RAPID indicating a preamble associated with a RAR-based DL EDT, and a combination of one MAC RAR and one MAC SDU corresponding thereto may exist. The MAC SDU was described in detail above.

A third embodiment of a configuration diagram of a random access response message for storing user data, in FIG. 1F (c), a subheader 1f-35 including a RAPID indicating a preamble associated with a RAR-based DL EDT is one MAC. It corresponds to RAR (1f-40) and one MAC SDU (1f-45). The subheader is located behind the BI subheader in the MAC header, and there is no order restriction with other E/T/RAPID MAC subheaders. The MAC RAR and MAC SDU mapped to the subheader are adjacent to each other. The positions of the mapped MAC RAR and MAC SDU in the MAC payload are the same as the positions of the subheaders in the MAC header. However, it is located in front of the padding. In one RAR, a plurality of subheaders including a RAPID indicating a preamble associated with a RAR-based DL EDT, and a combination of one MAC RAR and one MAC SDU corresponding thereto may exist. The MAC SDU was described in detail above.

In the fourth embodiment of the configuration diagram of the random access response message accommodating user data, in FIG. 1F(d), subheaders 1f-50, 1f-55 including the same RAPID indicating the preamble associated with the RAR-based DL EDT. ), one of the two sub-headers corresponds to one MAC RAR (1f-60), and the second sub-header corresponds to one MAC SDU (1f-65). In the MAC header, the first subheader is always positioned before the second subheader, and need not be adjacent to each other. The two subheaders are located behind the BI subheader in the MAC header, and there is no order restriction with other E/T/RAPID MAC subheaders. The MAC RAR and MAC SDU mapped to the two subheaders need not be adjacent to each other. The positions of the mapped MAC RAR and MAC SDU in the MAC payload are the same as the positions of the corresponding subheaders in the MAC header. However, it is located in front of the padding. The reason to define two subheaders having the same RAPID is to minimize the effect on the terminal that does not support the DL EDT. In one RAR, a plurality of subheaders including a RAPID indicating a preamble associated with a RAR-based DL EDT, and a combination of one MAC RAR and one MAC SDU corresponding thereto may exist. The MAC SDU was described in detail above.

1G is a flowchart of terminal operation in the present invention.

In step 1g-05, the terminal receives a paging message from the base station. In the paging, a paging record corresponding to the terminal exists. In addition, through the paging, an indicator instructing the performance of RAR-based DL EDT and dedicated preamble information are provided.

In step 1g-10, the terminal transmits the dedicated preamble to the base station.

In step 1g-15, the terminal receives the RAR from the base station.

In step 1g-20, the terminal decodes user data from the NAS container included in the received RAR.

In step 1g-25, the UE transmits msg3 using the UL grant provided by the RAR for ACK/NACK purposes. If there is user data to be transmitted in the uplink, msg3 is also included in the data. The data is stored in the NAS container, and a predetermined RRC message including the NAS container may be defined.

1H is a flowchart of the operation of a base station in the present invention.

In steps 1h-05, the base station receives paging for a specific terminal together with user data from the MME. At this time, the MME may instruct to apply the RAR-based DL EDT to deliver the user data to the terminal.

In steps 1h-10, the base station transmits a paging including an indicator indicating the performance of the RAR-based DL EDT and dedicated preamble information allocated for the RAR-based DL EDT to the terminal.

In steps 1h-15, the base station receives one preamble from the terminal.

In step 1h-20, the base station determines whether the preamble is the dedicated preamble provided.

In step 1h-25, if the preamble was a dedicated preamble allocated for DL EDT. The base station includes a MAC SDU including a corresponding MAC RAR and a NAS container containing user data in the RAR.

In steps 1h-30, if the preamble is not a dedicated preamble allocated for DL EDT. The base station includes the corresponding MAC RAR in the RAR.

In steps 1h-35, the base station transmits the configured RAR to the terminal.

In step 1h-40, the base station receives msg3 from the terminal. The msg3 may include a NAS container in which user data is stored.

1I is a flowchart of the MME operation in the present invention.

In step 1i-05, the MME receives capability information for a specific terminal from the base station. The capability information includes information on whether the terminal supports RAR-based DL EDT.

In step 1i-10, the MME triggers paging for the terminal and has user data to be transmitted through DL EDT.

In step 1i-15, the MME transmits the paging to the base station together with the user data if the base station supports RAR based DL EDT.

In step 1i-20, the MME receives ACK information indicating that the user data has been successfully transmitted from the base station.

1J shows the structure of the terminal.

Referring to the drawings, the terminal includes a radio frequency (RF) processor 1j-10, a baseband processor 1j-20, a storage unit 1j-30, and a controller 1j-40. .

The RF processing unit 1j-10 performs a function for transmitting and receiving a signal through a wireless channel such as band conversion and amplification of the signal. That is, the RF processing unit 1j-10 up-converts the baseband signal provided from the baseband processing unit 1j-20 to an RF band signal, transmits it through an antenna, and receives an RF band signal received through the antenna. Downconvert to baseband signal. For example, the RF processing unit 1j-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), and an analog to digital converter (ADC). Can be. In the figure, only one antenna is shown, but the terminal may have multiple antennas. In addition, the RF processing unit 1j-10 may include a plurality of RF chains. Furthermore, the RF processing unit 1j-10 may perform beamforming. For the beamforming, the RF processing unit 1j-10 may adjust the phase and magnitude of each of signals transmitted/received through a plurality of antennas or antenna elements. In addition, the RF processing unit may perform MIMO, and may receive multiple layers when performing the MIMO operation.

The baseband processing unit 1j-20 performs a conversion function between a baseband signal and a bit stream according to a physical layer standard of a system. For example, during data transmission, the baseband processor 1j-20 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit 1j-20 restores the received bit stream through demodulation and decoding of the baseband signal provided from the RF processing unit 1j-10. For example, in the case of conforming to an orthogonal frequency division multiplexing (OFDM) method, when transmitting data, the baseband processor 1j-20 generates complex symbols by encoding and modulating a transmission bit string, and subcarriers the complex symbols. After mapping to, OFDM symbols are constructed through inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processing unit 1j-20 divides the baseband signal provided from the RF processing unit 1j-10 into OFDM symbol units, and transmits to the subcarriers through fast Fourier transform (FFT) operation. After reconstructing the mapped signals, the received bit string is reconstructed through demodulation and decoding.

The baseband processor 1j-20 and the RF processor 1j-10 transmit and receive signals as described above. Accordingly, the baseband processor 1j-20 and the RF processor 1j-10 may be referred to as a transmitter, a receiver, a transceiver, or a communicator. Furthermore, at least one of the baseband processor 1j-20 and the RF processor 1j-10 may include a plurality of communication modules to support a plurality of different radio access technologies. In addition, at least one of the baseband processor 1j-20 and the RF processor 1j-10 may include different communication modules to process signals of different frequency bands. For example, the different radio access technologies may include a wireless LAN (eg, IEEE 802.11), a cellular network (eg, LTE), and the like. In addition, the different frequency bands may include a super high frequency (SHF) band (eg, 2.NRHz, NRhz) and a millimeter wave (mmband) band (eg, 60 GHz).

The storage unit 1j-30 stores data such as a basic program, an application program, and setting information for the operation of the terminal. In particular, the storage unit 1j-30 may store information related to a second access node that performs wireless communication using a second wireless access technology. Then, the storage unit 1j-30 provides data stored at the request of the control unit 1j-40.

The control unit 1j-40 controls overall operations of the terminal. For example, the controller 1j-40 transmits and receives signals through the baseband processor 1j-20 and the RF processor 1j-10. Further, the control unit 1j-40 writes and reads data in the storage unit 1j-40. To this end, the control unit 1j-40 may include at least one processor. For example, the controller 1j-40 may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls an upper layer such as an application program.

1K is a block diagram of a main station in a wireless communication system according to an embodiment of the present invention.

As shown in the figure, the base station includes an RF processing unit (1k-10), a baseband processing unit (1k-20), a backhaul communication unit (1k-30), a storage unit (1k-40), and a control unit (1k-50). It is configured to include.

The RF processor 1k-10 performs a function for transmitting and receiving a signal through a wireless channel such as band conversion and amplification of the signal. That is, the RF processor 1k-10 up-converts the baseband signal provided from the baseband processor 1k-20 into an RF band signal, transmits it through an antenna, and transmits an RF band signal through the antenna. Downconvert to baseband signal. For example, the RF processing unit 1k-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. In the figure, only one antenna is shown, but the first access node may include multiple antennas. In addition, the RF processing unit 1k-10 may include a plurality of RF chains. Furthermore, the RF processing unit 1k-10 may perform beamforming. For the beamforming, the RF processor 1k-10 may adjust the phase and magnitude of each of signals transmitted and received through multiple antennas or antenna elements. The RF processing unit may perform a downlink MIMO operation by transmitting one or more layers.

The baseband processor 1k-20 performs a conversion function between a baseband signal and a bit stream according to a physical layer standard of the first wireless access technology. For example, when transmitting data, the baseband processor 1k-20 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processor 1k-20 restores the received bit stream through demodulation and decoding of the baseband signal provided from the RF processor 1k-10. For example, according to the OFDM scheme, when transmitting data, the baseband processor 1k-20 generates complex symbols by encoding and modulating a transmission bit stream, mapping the complex symbols to subcarriers, and then IFFT OFDM symbols are configured through arithmetic and CP insertion. In addition, when receiving data, the baseband processor 1k-20 divides the baseband signal provided from the RF processor 1k-10 into units of OFDM symbols and restores signals mapped to subcarriers through FFT operation. After that, the received bit stream is restored through demodulation and decoding. The baseband processor 1k-20 and the RF processor 1k-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 1k-20 and the RF processing unit 1k-10 may be referred to as a transmission unit, a reception unit, a transmission/reception unit, a communication unit, or a wireless communication unit.

The backhaul communication unit 1k-30 provides an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 1k-30 converts a bit stream transmitted from the main station to another node, for example, an auxiliary base station, a core network, into a physical signal, and bit the physical signal received from the other node. Convert to heat.

The storage unit 1k-40 stores data such as a basic program, an application program, and setting information for the operation of the main station. In particular, the storage unit 1k-40 may store information on bearers allocated to the connected terminal, measurement results reported from the connected terminal, and the like. In addition, the storage unit 1k-40 may store information serving as a criterion for determining whether to provide or stop multiple connections to the terminal. Then, the storage unit 1k-40 provides data stored at the request of the control unit 1k-50.

The control unit 1k-50 controls overall operations of the main station. For example, the control unit 1k-50 transmits and receives signals through the baseband processing unit 1k-20 and the RF processing unit 1k-10 or through the backhaul communication unit 1k-30. Further, the control unit 1k-50 writes and reads data in the storage unit 1k-40. To this end, the control unit 1k-50 may include at least one processor.

1L is a configuration diagram of a random access response message accommodating an RAR subheader having an L field and an RAR having an L size in the present invention.

The subheader 1l-05 including the RAPID indicating the preamble associated with the RAR based DL EDT may correspond to one MAC RAR 1l-10. The sub-header is characterized by including a predetermined field indicating the length of the corresponding MAC RAR. The preamble indicated by the RAPID received in the subheader is used only for DL EDT purposes, and the preamble information may be broadcast as system information. The subheader including the RAPID for the DL EDT may always include an L field indicating the length of the MAC RAR corresponding thereto. That is, the terminal determines whether an L field exists in the subheader according to whether the RAPID is a DL EDT use. The corresponding MAC RAR is characterized by having a variable size. The storage order of the MAC RAR mapped to the subheader in the MAC payload of the RAR MAC PDU is the same as the storage order of the corresponding subheader in the MAC header of the RAR MAC PDU. The MAC RAR mapped to the subheader is located at least before padding. In one RAR, a plurality of subheaders including a RAPID indicating a preamble associated with a RAR-based DL EDT, and a combination of one MAC RAR and one MAC SDU corresponding thereto may exist. In the MAC RAR having the variable size, a NAS container containing user data is stored. In the NAS container, user data to be transmitted by the network to the terminal is stored.

1m is a configuration diagram of an RAR subheader including an L field in the present invention.

This is a block diagram of the E/T/RAPID/L MAC subheader. The E field indicates whether another subheader exists after the subheader. If the E field value is 1, then another subheader is present, but if the E field value is 0, then MAC RAR or padding is present. The T field indicates whether the subheader is an E/T/RAPID MAC subheader (or E/T/RAPID/L MAC subheader) or an E/T/R/R/BI MAC subheader. If the T field value is 0, it is an E/T/R/R/BI MAC subheader, and if the T field value is 1, it is an E/T/RAPID MAC subheader (or E/T/RAPID/L MAC subheader). . The RAPID field is the ID of the random access preamble, and is used to indicate the preamble that has been transmitted. The RAPID in the E/T/RAPID/L MAC subheader always indicates a preamble for EDT use. The L field (1m-05) indicates the length of the MAC RAR corresponding to the subheader. That is, the corresponding MAC RAR has a variable size. Although the size of the L field is represented by 1 byte in FIG. 1M, it may be larger or smaller.

1n is a configuration diagram of a MAC RAR including a NAS container in the present invention.

Timing Advance Command information indicates transmission timing information to be adjusted for uplink synchronization. UL grant is scheduling information of msg3. Temporary C-RNTI is used to indicate the DCI corresponding to msg4 in the PDCCH, and can be converted to C-RNTI after random access. The NAS container is stored behind the MAC RAR (1n-05). NAS container may have a variable size.

As another embodiment, MAC RAR having a NAS container of a fixed size may be considered. At this time, the L field is not required for the corresponding subheader. However, the size of a MAC RAR indicated by a subheader including a RAPID indicating a preamble for EDT use and a subheader not indicated is different. That is, the MAC RAR corresponding to the sub-header including the RAPID indicating the preamble for EDT use is larger than the conventional MAC RAR because the NAS container additionally stores the NAS container. The size of the NAS container is fixed, but is characterized by being defined in units of bytes.

Figure 1o is a flow chart of the terminal operation in the present invention.

In step 1o-05, the terminal receives a paging message from the base station. In the paging, a paging record corresponding to the terminal exists. In addition, through the paging, an indicator instructing the performance of RAR-based DL EDT and dedicated preamble information are provided.

In step 1o-10, the terminal transmits the dedicated preamble to the base station.

In step 1o-15, the terminal receives the RAR from the base station.

In step 1o-20, the UE recognizes a RAPID corresponding to a preamble for DL EDT use among the subheaders of the RAR.

In step 1o-25, the terminal determines that the subheader has an L field.

In step 1o-30, the UE decodes the MAC RAR corresponding to the subheader in consideration of the size indicated by the L field.

1p is a flow chart of the base station operation in the present invention.

The base station provides the terminal with a dedicated preamble list used for DL EDT using the system information.

In step 1p-05, the base station receives paging for a specific terminal together with user data from the MME. At this time, the MME may instruct to apply the RAR-based DL EDT to deliver the user data to the terminal.

In step 1p-10, the base station transmits a paging including an indicator indicating the performance of the RAR-based DL EDT and dedicated preamble information allocated for the RAR-based DL EDT to the terminal.

In step 1p-15, the base station receives one preamble from the terminal.

In step 1p-20, the base station determines whether the preamble is the dedicated preamble provided.

In step 1p-25, if the preamble was a dedicated preamble allocated for DL EDT, the base station is a MAC including a subheader having a RAPID and L field corresponding to the preamble and a NAS container corresponding to the subheader. Include RAR in RAR.

In step 1p-30, if the preamble is not a dedicated preamble allocated for DL EDT. The base station includes the corresponding MAC RAR in the RAR.

In step 1p-35, the base station transmits the configured RAR to the terminal.

In step 1p-40, the base station receives msg3 from the terminal. The msg3 may include a NAS container in which user data is stored.

<Second Example>

Hereinafter, the operation principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description, when it is determined that a detailed description of a known function or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or practice. Therefore, the definition should be made based on the contents throughout this specification.

In the following description of the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted. Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Terms used to identify a connection node (node) used in the following description, terms referring to network objects (network entities), terms referring to messages, terms referring to interfaces between network objects, terms referring to various identification information Etc. are exemplified for convenience of explanation. Accordingly, the present invention is not limited to the terms described below, and other terms indicating objects having equivalent technical meanings may be used.

For convenience of description below, the present invention uses terms and names defined in the 3GPP 3rd Generation Partnership Project Long Term Evolution (LTE) standard. However, the present invention is not limited by the terms and names, and can be applied to systems conforming to other standards. In the present invention, eNB may be used in combination with gNB for convenience of description. That is, a base station described as an eNB may indicate gNB.

2A is a diagram illustrating the structure of an LTE system according to an embodiment of the present invention.

Referring to Figure 2a, the radio access network of the LTE system as shown in the next generation base station (Evolved Node B, hereinafter referred to as ENB, Node B or base station) (2a-05, 2a-10, 2a-15, 2a-20) It consists of MME (2a-25, Mobility Management Entity) and S-GW (2a-30, Serving-Gateway). User equipment (hereinafter referred to as UE or UE) 2a-35 accesses an external network through ENBs 2a-05 to 2a-20 and S-GW 2a-30.

In FIG. 2A, ENBs 2a-05 to 2a-20 correspond to existing Node Bs of the UMTS system. The ENB is connected to the UE (2a-35) through a radio channel and performs a more complicated role than the existing Node B. In the LTE system, all user traffic, including real-time services such as VoIP (Voice over IP) through the Internet protocol, is serviced through a shared channel, so status information such as buffer status of UEs, available transmission power status, channel status, etc. It is necessary to have a device for scheduling by collecting and ENB (2a-05 ~ 2a-20) is in charge. One ENB usually controls multiple cells. For example, in order to realize a transmission rate of 100 Mbps, the LTE system uses, for example, an orthogonal frequency division multiplexing (OFDM) in a 20 MHz bandwidth as a radio access technology. In addition, an adaptive modulation & coding (hereinafter referred to as AMC) method is applied to determine a modulation scheme and a channel coding rate according to a channel condition of a terminal. The S-GW 2a-30 is a device that provides a data bearer, and creates or removes a data bearer under the control of the MME 2a-25. MME is a device that is responsible for various control functions as well as mobility management functions for terminals, and is connected to multiple base stations.

2B is a diagram illustrating a radio protocol structure in an LTE system according to an embodiment of the present invention.

Referring to Figure 2b, the radio protocol of the LTE system is the PDCP (Packet Data Convergence Protocol 2b-05, 2b-40), RLC (Radio Link Control 2b-10, 2b-35), MAC (Medium Access) in the terminal and the ENB, respectively. Control 2b-15, 2b-30). PDCP (Packet Data Convergence Protocol) (2b-05, 2b-40) is responsible for IP header compression/restore. The main functions of PDCP are summarized as follows.

-Header compression and decompression: ROHC only

-Transfer of user data

-In-sequence delivery of upper layer PDUs at PDCP re-establishment procedure for RLC AM

-For split bearers in DC (only support for RLC AM): PDCP PDU routing for transmission and PDCP PDU reordering for reception)

-Duplicate detection of lower layer SDUs at PDCP re-establishment procedure for RLC AM

-Retransmission of PDCP SDUs at handover and, for split bearers in DC, of PDCP PDUs at PDCP data-recovery procedure, for RLC AM)

-Encryption and decryption function (Ciphering and deciphering)

-Timer-based SDU discard function (Timer-based SDU discard in uplink.)

Radio link control (hereinafter referred to as RLC) (2b-10, 2b-35) reconfigures the PDCP packet data unit (PDU) to an appropriate size to perform ARQ operation and the like. The main functions of RLC are summarized as follows.

-Data transfer function (Transfer of upper layer PDUs)

-ARQ function (Error Correction through ARQ (only for AM data transfer))

-Concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer)

-Re-segmentation of RLC data PDUs (only for AM data transfer)

-Reordering of RLC data PDUs (only for UM and AM data transfer)

-Duplicate detection (only for UM and AM data transfer)

-Error detection function (Protocol error detection (only for AM data transfer))

-RLC SDU deletion function (RLC SDU discard (only for UM and AM data transfer))

-RLC re-establishment

MAC (2b-15, 2b-30) is connected to several RLC layer devices configured in one terminal, and performs an operation of multiplexing RLC PDUs to MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The main functions of MAC are summarized as follows.

-Mapping function (Mapping between logical channels and transport channels)

-Multiplexing and demultiplexing function (Multiplexing/demultiplexing of MAC SDUs belonging to one or different logical channels into/from transport blocks (TB) delivered to/from the physical layer on transport channels)

-Scheduling information reporting function

-HARQ function (Error correction through HARQ)

-Priority handling between logical channels (Priority handling between logical channels of one UE)

-Priority handling between UEs (Priority handling between UEs by means of dynamic scheduling)

-MBMS service identification function

-Transport format selection function

-Padding function

The physical layer (2b-20, 2b-25) channel-codes and modulates the upper layer data, makes it into an OFDM symbol and transmits it to a radio channel, or demodulates and decodes an OFDM symbol received through the radio channel and transmits it to the upper layer. Do the action.

2C is a diagram illustrating the structure of a next-generation mobile communication system according to an embodiment of the present invention.

Referring to FIG. 2C, a radio access network of a next-generation mobile communication system (hereinafter referred to as NR or 2g) includes a next-generation base station (New Radio Node B, NR gNB or NR base station) 2c-10 and NR CN (2c). -05, New Radio Core Network). The user terminal (New Radio User Equipment, NR UE or terminal) 2c-15 accesses the external network through the NR gNB 2c-10 and the NR CN 2c-05.

In FIG. 2C, NR gNB 2c-10 corresponds to an evolved node B (eNB) of an existing LTE system. The NR gNB is connected to the NR UE (2c-15) through a radio channel and can provide superior service than the existing Node B. In the next-generation mobile communication system, since all user traffic is serviced through a shared channel, a device is required to collect and schedule status information such as the buffer status of UEs, available transmission power status, and channel status, and this is NR NB (2c-10) is in charge. One NR gNB usually controls multiple cells. In order to implement ultra-high-speed data transmission compared to current LTE, it may have more than the existing maximum bandwidth, and orthogonal frequency division multiplexing (hereinafter referred to as OFDM) as a wireless access technology may additionally incorporate beamforming technology. . In addition, an adaptive modulation & coding (hereinafter referred to as AMC) method is applied to determine a modulation scheme and a channel coding rate according to a channel state of a terminal. NR CN (2c-05) performs functions such as mobility support, bearer setup, and QoS setup. NR CN is a device that is responsible for various control functions as well as mobility management functions for terminals, and is connected to multiple base stations. In addition, the next generation mobile communication system can be linked with the existing LTE system, and the NR CN is connected to the MME (2c-25) through a network interface. MME is connected to the existing base station eNB (2c-30).

2D is a diagram illustrating a radio protocol structure of a next generation mobile communication system according to an embodiment of the present invention.

2D is a diagram illustrating a radio protocol structure of a next generation mobile communication system to which the present invention can be applied. .

Referring to Figure 2d, the radio protocol of the next-generation mobile communication system is NR SDAP (2d-01, 2d-45), NR PDCP (2d-05, 2d-40), NR RLC (2d-10) at the terminal and the NR base station, respectively. , 2d-35), NR MAC (2d-15, 2d-30).

The main functions of the NR SDAP (2d-01, 2d-45) may include some of the following functions.

- Transfer function of user data (transfer of user plane data)

- QoS flow and data bearer mapping function for uplink and downlink (mapping between a QoS flow and a DRB for both DL and UL)

- Marking QoS flow ID for both uplink and downlink (marking QoS flow ID in both DL and UL packets)

- Reflective QoS flow to DRB mapping for the UL SDAP PDUs for uplink SDAP PDUs.

For the SDAP layer device, the UE can be set whether to use the header of the SDAP layer device or the function of the SDAP layer device for each PDCP layer device, for each bearer, or for each logical channel through an RRC message, and the SDAP header When is set, the NAS QoS reflection setting 1-bit indicator (NAS reflective QoS) of the SDAP header and the AS QoS reflection setting 1-bit indicator (AS reflective QoS) allow the UE to map uplink and downlink QoS flows and mapping information for the data bearer. You can instruct it to update or reset. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used as data processing priority, scheduling information, etc. to support a smooth service.

The main functions of NR PDCP (2d-05, 2d-40) may include some of the following functions.

Header compression and decompression (ROHC only)

-Transfer of user data

-In-sequence delivery of upper layer PDUs

-Out-of-sequence delivery of upper layer PDUs

-PDCP PDU reordering for reception

-Duplicate detection of lower layer SDUs

-Retransmission of PDCP SDUs

-Encryption and decryption function (Ciphering and deciphering)

-Timer-based SDU discard function (Timer-based SDU discard in uplink.)

In the above, the order reordering function of the NR PDCP device refers to a function of reordering PDCP PDUs received from a lower layer in order based on a PDCP SN (sequence number), and transmitting data to a higher layer in the reordered order. It may include, or, without considering the order, may include a function for immediately transmitting, may include a function to record the lost PDCP PDUs by rearranging the order, and report the status of the lost PDCP PDUs It may include a function for transmitting to the sender, and may include a function for requesting retransmission for lost PDCP PDUs.

The main functions of the NR RLC (2d-10, 2d-35) may include some of the following functions.

-Data transfer function (Transfer of upper layer PDUs)

-In-sequence delivery of upper layer PDUs

-Out-of-sequence delivery of upper layer PDUs

-ARQ function (Error Correction through ARQ)

-Concatenation, segmentation and reassembly of RLC SDUs

-Re-segmentation of RLC data PDUs

-Reordering of RLC data PDUs

-Duplicate detection function

-Protocol error detection

-RLC SDU deletion function (RLC SDU discard)

-RLC re-establishment

In the above, the in-sequence delivery of the NR RLC device refers to a function of sequentially transmitting RLC SDUs received from a lower layer to an upper layer, and one RLC SDU is originally divided into multiple RLC SDUs and received. If it is, it may include a function to reassemble and deliver it, and may include a function to rearrange the received RLC PDUs based on RLC sequence number (SN) or PDCP sequence number (SN). It may include a function of recording lost RLC PDUs, may include a function of reporting a status of lost RLC PDUs to a transmitting side, and a function of requesting retransmission of lost RLC PDUs. When there is a lost RLC SDU, it may include a function of forwarding only the RLC SDUs up to the lost RLC SDU to the upper layer in order, or if there is a lost RLC SDU, a timer if a predetermined timer has expired It may include a function of forwarding all RLC SDUs received before the start to the upper layer in sequence, or if a predetermined timer expires even if there is a missing RLC SDU, all RLC SDUs received so far in order to the upper layer. It can include the ability to deliver. In addition, the RLC PDUs can be processed in the order in which they are received (regardless of the sequence number and sequence number, in order of arrival) and delivered to the PDCP device in any order (out-of sequence delivery). Thereafter, segments that are stored in a buffer or to be received at a later time are received, reconstructed into a single RLC PDU, processed, and then transmitted to a PDCP device. The NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or replaced by a multiplexing function of the NR MAC layer.

In the above, out-of-sequence delivery of the NR RLC device refers to a function of directly transmitting RLC SDUs received from a lower layer to an upper layer regardless of order, and one RLC SDU originally has multiple RLCs. When divided and received into SDUs, it may include a function of reassembling it and transmitting it, and may include a function of storing RLC SNs or PDCP SNs of received RLC PDUs and sorting the order to record lost RLC PDUs. Can be.

The NR MACs 2d-15 and 2d-30 may be connected to several NR RLC layer devices configured in one terminal, and the main function of the NR MAC may include some of the following functions.

-Mapping function (Mapping between logical channels and transport channels)

-Multiplexing and demultiplexing functions (Multiplexing/demultiplexing of MAC SDUs)

-Scheduling information reporting function

-HARQ function (Error correction through HARQ)

-Priority handling between logical channels (Priority handling between logical channels of one UE)

-Priority handling between UEs (Priority handling between UEs by means of dynamic scheduling)

-MBMS service identification function

-Transport format selection function

-Padding function

The NR PHY layer (2d-20, 2d-25) channel-codes and modulates the upper layer data, makes it an OFDM symbol and transmits it to a radio channel, or demodulates and decodes an OFDM symbol received through the radio channel to the upper layer Transfer operation can be performed.

Figure 2e is a procedure according to an embodiment of the present invention, the base station releases the connection of the terminal, the terminal to switch from the RRC connected mode (RRC connected mode) to the RRC idle mode (RRC idle mode), the terminal is connected to the base station It is a diagram for explaining a procedure for switching from RRC idle mode to RRC connected mode by setting.

According to an embodiment of the present invention, the base station sends a RRC connection release message (RRCRelease message) to the terminal when the terminal transmitting/receiving data in the RRC connection mode has no transmission or reception of data for a predetermined reason or for a certain period of time. Can be switched to (2e-01). Subsequently, a terminal that has not currently established a connection (hereinafter referred to as an idle mode UE) may perform an RRC connection establishment process with a base station when data to be transmitted occurs. The UE establishes reverse transmission synchronization with the base station through a random access process and transmits an RRC connection request message (RRCSetupRequest message) to the base station (2e-05). The message may include an identifier of the terminal and a reason for establishing a connection (establishmentCause). The base station transmits an RRC connection setup message (RRCSetup message) so that the UE establishes an RRC connection (2e-10). The message may contain RRC connection configuration information and the like. RRC connection is also called SRB (Signaling Radio Bearer), and is used to transmit and receive RRC messages, which are control messages between the terminal and the base station. The UE establishing the RRC connection transmits an RRC connection setup complete message (RRCSetupComplete message) to the base station (2e-15). The message includes a service request message (Service Request message) in which the terminal requests the AMF to establish a bearer for a given service. The base station transmits the initial terminal message containing the service request message received in the RRC connection establishment complete message to the AMF (2e-20), and the AMF determines whether to provide the service requested by the terminal. As a result of the determination, if the terminal decides to provide the requested service, the AMF transmits an initial UE context setup request message to the base station (2e-25). The message includes QoS (Quality of Service) information to be applied when setting a Data Radio Bearer (DRB), and security-related information (eg, Security Key, Security Algorithm) to be applied to the DRB. The base station exchanges a security mode command message (SecurityModeCommand message) 2e-30 and a security mode completion message (SecurityModeComplete message) 2e-35 to establish security with the terminal. When the security setting is completed, the base station transmits an RRC connection reconfiguration message (RRCReconfiguration message) to the terminal (2e-40). The message includes the DRB configuration information to be processed by the user data, and the UE applies the information to set the DRB and transmits an RRC connection reconfiguration completion message (RRCReconfigurationComplete message) to the base station (2e-45). Upon completion of the UE and DRB setup, the base station transmits an initial UE context setup request response message (2e-50) to the AMF, and the AMF receiving the AMF receives the UPF and the session management procedure (Session Management Procedure). To establish a PDU session (2e-55). When all the above processes are completed, the terminal transmits and receives data through the base station and the UPF (2e-60, 2e-65). This general data transmission process is largely composed of three steps: RRC connection setup, security setup, and DRB setup. In addition, the base station may transmit an RRCReconfiguration message in order to newly add, add, or change settings to the terminal for a predetermined reason (2e-70).

As described above, many signaling procedures are required for the UE to set the RRC connection and switch from the RRC idle mode to the RRC connected mode. Therefore, the RRC inactive mode may be newly defined in the next generation mobile communication system, and in the new mode, the terminal and the base station store the context of the terminal, and if necessary, may maintain the S1 bearer. When attempting to reconnect to this network, the RRC reconnection setup procedure proposed below can be used to connect faster and transmit and receive data with fewer signaling procedures.

Figure 2f is a procedure according to an embodiment of the present invention, the base station releases the connection of the terminal, and the terminal switches from the RRC connected mode (RRC connected mode) to the RRC inactive mode (RRC inactive mode) and the terminal connects to the base station It is a diagram for explaining a procedure for switching from RRC inactive mode to RRC connected mode by setting.

In FIG. 2F, the terminal 2f-01 performs a network connection with the base station 2f-02 and can transmit and receive data. If, for some reason, the base station needs to transition the terminal to the RRC deactivation mode, the base station sends the RRC connection release message (RRCRelease message) (2f-05) including suspend configuration information (suspendConfig) to the terminal to deactivate the RRC mode. You can transition to

When the terminal receives the RRCRelease message (2f-05) including the suspend configuration information, the proposed terminal operation is as follows.

One. If the RRCRelease message includes suspend configuration information (suspendConfig), the terminal may apply the received suspend configuration information.

A. If there is no LAN indication area information (ran-NotificationAreaInfo) in the suspend setting information,

i. The terminal may apply the LAN indication area information that has been stored. This is for supporting delta configuration to the terminal because the size of the LAN indication area information is large.

B. If there is LAN instruction area information in the suspend setting information,

i. The terminal may update the stored values with new LAN indication area information included in the suspend configuration information of the RRCRelease message.

C. If t380 is not in the suspend configuration information,

i. The terminal can release the previously stored t380.

D. If there is t380 in the suspend configuration information,

i. The terminal may store t380 included in the suspend configuration information of the RRCRelease message.

E. The terminal may store a complete terminal connection resumption identifier (FullI-RNTI), a divided terminal connection resumption identifier (ShortI-RNTI), an NCC (nextHopChainingCount), and a LAN paging cycle (ran-PagingCycle) included in the suspend configuration information.

F. In addition, the terminal may reset the MAC layer device. This is to prevent unnecessary retransmission when data stored in the HARQ buffer resumes connection again.

G. In addition, RLC layer devices can be re-established for all SRBs and DRBs. This is to prevent unnecessary retransmission when data stored in the RLC buffer resumes connection, and to initialize variables for future use.

H. If the RRCRelease message with the suspend configuration information is not received in response to the RRC connection resume request message (RRCResumeRequest message) above

i. The terminal may store the terminal context. The terminal context includes current RRC configuration information, current security context information, PDCP status information including ROHC status information, SDAP configuration information, a terminal cell identifier (C-RNTI) used in a source PCell, and a cell of the source cell. It may include an identifier (CellIdentity) and a physical cell identity (physical cell identity).

I. In addition, all SRBs and DRBs except SRB0 can be suspended.

J. In addition, the t380 timer may be driven with a periodic LAN instruction area update timer value (PeriodicRNAU-TimerValue) included in the suspend setting information.

K. In addition, the suspension of the RRC connection can be reported to the upper layer.

L. In addition, it configures lower layer devices to stop integrity protection and encryption.

M. And the terminal transitions to the RRC deactivation mode.

In the above description, the terminal 2f-10 transitioning to the RRC deactivation mode has a LAN-based indication area (RAN-) that does not belong to the established LAN indication area information after the t380 timer, which has been driven while moving, has expired or has undergone a cell reselection process. based Notification Area (RNA), when LAN paging is received, when data to be transmitted to the base station occurs, an RRC connection resume procedure can be performed with the base station (2f-10).

In step 2f-10, when the upper layer requests to resume the RRC connection or the RRC requests to resume the RRC connection, the RRC inactive mode terminal performs a random access procedure, and the proposed terminal operation when transmitting the RRC message to the base station is as follows. (2f-15).

One. When the useFullResumeID field is signaled in the system information (SIB1), the UE may select a message to be transmitted to the base station as RRCResumeRequest1. The UE may prepare for transmission by including resumeIdentity in the RRCResumeRequest1 message as a stored full UE connection resume identifier value (fullI-RNTI value). Otherwise, the terminal may select a message to be transmitted to the base station as an RRCResumeRequest. The terminal may prepare to transmit the shortResumeIdentity as a stored segmented terminal connection resumption identifier value (shortI-RNTI value) in the RRCResumeRequest message.

2. The terminal may set a reason (resumeCause) to resume the connection.

3. If the UE provides the PLMN from the upper layer devices or the NAS layer, the PLMN selected from the upper layer devices or the NAS layer is selectedPLMN-Identity from the plmn-IdentityList included in SIB1 and included in the RRCResumeRequest message or RRCResumeRequest1 message. To prepare for transmission.

4. The terminal can prepare the MAC-I by calculating it and including it in the selected message.

5. RRC configuration information and security context information can be recovered from the stored terminal context except for the cell group configuration information (cellGroupConfig).

6. The terminal updates the new KgNB security key based on the current KgNB security key and the NH (NextHop) value and the stored NCC value.

7. In addition, the terminal derives new security keys (K_RRCenc, K_RRC_int, K_UPint, K_UPenc) to be used in the integrity-free protection and verification procedure and the encryption and decryption procedure using the newly updated KgNB security key.

8. In addition, the UE resumes the integrity protection and verification procedure by applying the updated security keys and the previously set algorithm to all bearers except SRB0, and then applies integrity verification and protection to data transmitted and received. This is to increase reliability and security for data transmitted and received from SRB1 or DRBs later.

9. And the terminal resumes the encryption and decryption procedure by applying the updated security keys and the previously set algorithm to all bearers except SRB0, and then applies encryption and decryption to data transmitted and received. This is to increase reliability and security for data transmitted and received from SRB1 or DRBs later.

10. The UE may recover the PDCP state and re-establish PDCP entities for SRB1.

11. The terminal resumes SRB1. This is because the RRCResume message will be received as SRB1 in response to the RRCResumeRequset message or RRCResumeRequest1 message to be transmitted.

12. The UE constructs a message selected from the above for transmission to the base station, that is, an RRCResumeRequset message or an RRCResumeRequest1 message, and transmits it to lower layer devices.

13. When the UE transmits the RRCResumeRequest message or the RRCResumeRequest1 message to the base station, the UE drives the timer T319.

In the above, a random access procedure is performed to perform a LAN-based indication region update (RNA Update, RNAU) procedure, and an RRCResumeRequest message or RRCResumeRequest1 message is transmitted to the base station, and then an RRC connection resume message (RRCResume message) is received in response to the random access procedure. When proposed, the proposed terminal operation is as follows (2f-20).

One. When the UE transmits the RRCResumeRequest message or the RRCResumeRequest1 message to the base station, it stops the timer T319 that was started.

2. If the RRCResume message includes full configuration information (fullConfig), the UE performs a full configuration procedure (full configuration procedure). Otherwise, upon receiving the message, the UE restores the PDCP state and resets the COUNT value for SRB2 and all DRBs. And the terminal restores the cell group configuration information (cellGroupConfig) from the stored terminal context. And the terminal instructs this to the lower layer devices.

3. The terminal releases the complete terminal connection resume identifier (FullI-RNTI), the divided terminal connection resume identifier (ShortI-RNTI), and the stored terminal context. At this time, the LAN indication area information (ran-NotificatioAreaInfo) is not released.

4. If the RRCResume message includes master cell group configuration information, a cell group configuration procedure may be performed according to the configuration information.

5. If the message includes bearer configuration information (radioBearerConfig), the bearer can be configured according to the configuration information.

6. The UE resumes SRB2 and all DRBs.

7. The terminal discards any stored cell reselection priority information. The information may be cell reselection priority information stored in CellReselectionPriorities that may be stored in an RRCRelease message or inherited from another RAT.

8. The terminal may stop when the timer T320 is running.

9. If the RRCResume message includes frequency measurement configuration information (measConfig), frequency measurement can be performed according to the configuration information.

10. If the RRC connection is suspended, frequency measurement can be resumed.

11. The terminal transitions to the RRC connection mode (2f-25).

12. The terminal instructs the upper layer devices that the stopped RRC connection has been resumed.

13. The terminal may stop the cell reselection procedure.

14. The terminal considers the currently connected cell as a primary cell (PCell).

15. The RRC connection resumption completion message (RRCResumeComplete message) is configured and transmitted as follows for transmission to lower layer devices (2f-30).

A. If the NAS PDU is provided by the upper layer devices, it can be included in the dedicated NAS-Message.

B. If the PLMN is provided in the upper layer devices or the NAS layer, the PLMN selected in the upper layer devices or the NAS layer from the plmn-IdentityList included in SIB1 may be set as the selectedPLMN-Identity.

2G is a diagram illustrating a process of reselecting a cell when the UE is in an RRC idle mode or an RRC inactive mode, according to an embodiment of the present invention.

In the cell reselection process, a UE in an RRC idle mode or an RRC inactive mode has a quality of service of a serving cell due to a predetermined reason or movement. When it is lower than the service quality of ), it may mean a procedure of determining whether to maintain the current serving cell or reselect a cell as a neighbor cell.

In the case of handover, whether the handover operation is determined by the network (MME or AMF or source eNB or source gNB), whereas in the case of cell reselection, the terminal determines whether or not to perform cell reselection operation based on the measured value of the terminal. You can. The cell to be reselected while the terminal moves is a cell that uses the same NR frequency (intra-frequency), a cell that uses a different NR frequency (inter-frequency), or other radio access technology as the serving cell currently being camped on. It may be a cell used (inter-RAT (Radio Access Technology)).

The terminal 2g-01 in the RRC idle mode or the RRC inactive mode may perform a series of operations while camping on the serving cell (2g-05).

In step 2g-10, the UE in the RRC idle mode or RRC inactive mode may receive system information broadcast by the base station of the serving cell. At this time, the RRC idle mode or RRC deactivated mode terminal may not receive system information broadcast by the base station of the neighboring cell. System information may be divided into a master information block (MIB) and system information blocks (System Information Blocks, SIBs). Additionally, the system information blocks may be referred to by dividing them into SI messages (eg, SIB2, SIB3, SIB4, or SIB5) except SIB1 and SIB1. The RRC idle mode or RRC deactivation mode terminal may receive and read system information (eg, MIB or SIB1 or SIB2) broadcast by the base station of the corresponding cell before camping on the serving cell. For reference, MIB and SIB1 may be system information commonly applied to all terminals. SIB2 may be system information commonly applied to a UE in an RRC idle mode or an RRC deactivated mode to reselect intra-frequency, inter-frequency, and inter-RAT cells. SIB3, SIB4, and SIB5 may include information necessary for a UE in RRC idle mode or RRC deactivated mode to reselect a cell.

SIB1 may include parameters such as minimum reception level or minimum signal quality or threshold used when determining whether to measure a serving cell signal, and this information may be applied cell-specific. SIB2, SIB3, SIB4, and SIB5 may include information about parameters such as minimum reception level or minimum signal quality or threshold used when determining whether to measure a neighbor cell signal. Specifically, SIB2 includes common information for intra-frequency, inter-frequency, and inter-RAT cell reselection, SIB3 includes information for intra-frequency cell reselection only, and SIB4 inter-frequency cell reselection. Only information is included, and SIB5 may include information only for inter-RAT cell reselection.

In steps 2g-15, the RRC idle mode or RRC deactivated mode terminal wakes up every discontinuous reception (DRX) cycle to determine the absolute signal strength of the serving cell (Reference Signal Received Power (RSRP, Qrxlevmeas) and relative signal quality (Reference Signal Received Quality) (RSRQ), Qqualmeas) can be measured (2g-15) The operation of the proposed UE when deriving a measurement quantity of a cell is as follows.

One. In the case of selecting a cell performing a plurality of beam operations (For cell selection in multi-beam operations), a measurement value of the cell may be derived by a terminal implementation.

2. When re-selecting a cell performing multiple beam operations (For cell reselection in multi-beam operations), the measured value of the cell may be derived based on a plurality of beams corresponding to the same cell based on SSB, It can be one of the following:

A. If nrofSS-BlocksToAverage or absThreshSS-BlocksConsolidation is not set in SIB2, or the measured value of the beam with the strongest signal is less than or equal to the set absThreshSS-BlocksConsolidation.

i. The measured value of the beam with the strongest signal can be derived as the measured value of the cell.

B. If not,

i. The average linear power values up to nrofSS-BlocksToAverage among the measured values of the largest beam larger than the set absThreshSS-BlocksConsolidation can be derived as the measured values of the cell (derive a cell measurement quantity as the linear average of the power values up to nrofSS -BlocksToAverage of highest beam measurement quantity values above absThreshSS-BlocksConsolidation).

The UE may calculate the reception level (Srxlev) and reception quality (Sqaul) of the serving cell using the parameters received from SIB1 through these measurement values. The UE may determine whether to perform neighbor cell measurement for cell reselection by comparing the calculated values with threshold values. The reception level (Srxlev) and reception quality (Sqaul) of the serving cell may be determined through Equation 1 below.

<Equation 1>

The definition of parameters used in Equation 1 may be determined by referring to the 3GPP standard document "38.304: User Equipment (UE) procedures in Idle mode and RRC Inactive state". Hereinafter, embodiments of the present disclosure to which Equation 1 is applied are also the same.

In order to minimize battery consumption, the RRC idle mode or RRC deactivation mode terminal does not always measure neighbor cells, but determines whether to perform neighbor cell measurement based on a measurement rule. It can be judged whether or not (2g-20). At this time, the RRC idle mode or RRC deactivation mode terminal does not receive the system information broadcasted by the base station of the neighboring cell, and can perform neighboring cell measurement using the system information broadcasted by the serving cell currently being camped on. If the reception level (Srxlev) and reception quality (Squal) of the current serving cell measured in steps 2g-15 becomes smaller than a threshold (Srxlev <= S _IntraSearchP and Squal <= S _IntraSeachQ ), RRC idle mode or RRC deactivation The mode terminal can measure neighboring cells using the same frequency as the serving cell (2g-20). That is, the signal quality (Squal) or reception level (Srxlev) of neighboring cells using the same frequency as the serving cell may be derived based on SIB2 or SIB3 broadcast from the serving cell (Equation 1 is applied).

For reference, information on threshold values for S _IntraSearchP and S _IntraSearchQ is included in SIB2. In addition, for inter-frequency/inter-RAT cells having a higher priority than the frequency of the current serving cell, neighbor cell measurement can be performed regardless of the quality of the serving cell (2g-20). That is, the signal quality (Squal) or reception level (Srxlev) of inter-frequency cells having a higher priority than the frequency of the serving cell is derived based on SIB4 broadcast from the serving cell (Equation 1 is applied), and the frequency of the serving cell The signal quality (Squal) or reception level (Srxlev) of inter-RAT cells having higher priority may be derived based on SIB5 broadcast from the serving cell (Equation 1 applied). In addition, for inter-frequency cells having the same or lower priority than the frequency of the serving cell or inter-RAT frequency cells having a lower priority than the frequency of the serving cell, the reception level (Srxlev) of the current serving cell measured in steps 2g-15. When the and the reception quality (Squal) becomes smaller than the threshold (Srxlex <= S _{nonIntraSearchP} and Squal <= S _intraSearchQ ), the RRC idle mode or RRC deactivation mode UE is configured with neighboring cells or serving cells that use a different frequency from the serving cell. Cells using other wireless access technologies can be measured (2g-20). That is, the signal quality (Squal) or the reception level (Srxlev) of the inter-frequency cell(s) having a priority equal to or lower than the frequency of the serving cell is derived based on SIB4 broadcast from the serving cell (Equation 1 applied) ), signal quality (Squal) or reception level (Srxlev) of the inter-RAT cell(s) having a priority lower than the frequency of the serving cell may be derived based on SIB5 broadcast from the serving cell (Equation 1 applied). . For reference, the threshold information for S _{nonIntraSearchP} and S _{nonIntraSearchQ} is included in SIB2.

The RRC idle mode or RRC deactivation mode UE may perform a cell re-selection evaluation process based on priority (CellReselectionPriority) based on the measured values (2g-20) of neighboring cells (2g) -25). That is, when multiple cells satisfying cell re-selection criteria have different priorities, reselecting a frequency/RAT cell having a high priority is a frequency/RAT cell having a low priority. Cell reselection to a higher priority RAT/frequency shall take precede over a lower priority RAT/frequency if multiple cells of different priorities fulfil the cell reselection criteria. The RRCRelease received when priority information is included in system information (SIB1, SIB2, SIB3, SIB4, and SIB5) broadcast from the serving cell or is switched from RRC connected mode to RRC idle mode or RRC disabled mode Included in the message. The UE operation for the re-selection evaluation procedure of the inter-frequency/inter-RAT cell, which has a higher priority than the current serving cell frequency, is as follows.

1st action:

If the threshold for threshServingLowQ is included in SIB2 and is broadcast and the UE is 1 second after camp-on in the current serving cell, the signal quality (Squal) of the inter-frequency/inter-RAT cell is a threshold value during a specific time Treselection _RAT If it is greater than Thresh _X,HighQ (Squal> Thresh _X,HighQ during a time interval Treselection _RAT ), the UE may perform reselection to an inter-frequency/inter-RAT cell.

2nd action:

If the terminal cannot perform the first operation, it may perform the second operation.

If the UE has camped on the current serving cell for 1 second, and the inter-frequency/inter-RAT cell reception level (Srxlev) is greater than the threshold Thresh _X,HighP during a specific time Treselection _RAT (Srxlev> Thresh _{X , HighP)} During a time interval _{Treselection -RAT-} ), the UE may _perform reselection to an inter-frequency/inter-RAT cell.

Here, the terminal is inter-frequency cell signal quality (Squal), reception level (Srxlev), thresholds (Threh _{X, HighQ} , Thresh _{X , HighP} ), _{Treselection RAT} Based on the values, that is, information included in the SIB4 broadcast from the serving cell, the first operation or the second operation may be performed. In addition, the terminal is inter-RAT cell signal quality (Squal), reception level (Srxlev), threshold (Thresh _{X, HighQ,} Thresh _{X , HighP} ), _{Treselection RAT} Based on the values, that is, information included in the SIB5 broadcast from the serving cell, the first operation or the second operation may be performed. For example, Q _{qualmin in} SIB4 Value or Q _rxlevmin Values are included, and signal quality (Squal) or reception level (Srxlev) of an inter-frequency cell may be derived based on the values.

In addition, the operation of the UE for the reselection evaluation procedure of the intra-frequency/inter-frequency cell having the same priority as the frequency of the current serving cell is as follows.

Third action:

When the signal quality (Squal) and the reception level (Srxlev) of the intra-frequency/inter-frequency cell is greater than 0, rank for each cell may be derived based on the measured value (RSRP) (The UE shall perform ranking of all) cells that fulfils the cell selection criterion S). Rank of the serving cell and the neighboring cells may be calculated through Equation 2 below.

<Equation 2>

R _s = Q _meas,s + Q _hyst

R _n = Q _meas,n -Qoffset

A. Here, Q _meas,s is the RSRP measurement value of the serving cell, Q _meas,n is the RSRP measurement value of the surrounding cell, Q _hyst is the hysteresis value of the serving cell, and Qoffset is the offset between the serving cell and surrounding cells. Q _hyst value is included in SIB2, and this value can be commonly used for reselection of intra-frequency/inter-frequency cells. In the case of reselection of intra-frequency cells, Qoffset is signaled for each cell, and is applied only to the indicated cell, and is included in SIB3. In the case of re-selection of an inter-frequency cell, Qoffset is signaled for each cell, is applied only to the indicated cell, and is included in SIB4. When rangetoBestCell is not set in SIB2 broadcast from the serving cell, the rank of the neighboring cell obtained from Equation 2 during a specific time Treselection _RAT is greater than the rank of the serving cell (R _n > R _s ) and camp-on to the current serving cell. If it exceeds 1 second, it can camp on the optimal cell among the surrounding cells. When rangeToBestCell is set in SIB2 broadcast from a serving cell, among cells having an R value belonging to rangeToBestCell of the R value of the highest ranked cell, the cell having the largest number of beams greater than absThreshSS-BlocksConsolidation (cell with the Reselection may be performed with the highest number of beams above the threshold (ie absThreshSS-BlocksConsolidation) among the cells whose R value is within rangeToBestCell of the R value of the highest ranked cell. If the new cell that satisfies the above condition is better than the serving cell during a specific time Treselection _RAT (the new cell is better than the serving cell during a time interval Treselection _RAT ), if the current serving cell camp-on limit exceeds 1 second, a new cell Reselection can be performed with a cell.

In addition, the operation of the UE for the reselection evaluation procedure of the inter-frequency/inter-RAT cell having a lower priority than the frequency of the current serving cell is as follows.

4th action:

If the threshold for threshServingLowQ is included in SIB2 and is broadcasted, and if the UE has camped on the current serving cell for 1 second, the signal quality (Sqaul) of the current serving cell is _lower than the threshold Thresh _{Serving and LowQ} (Squal <Thresh _{Serving , LowQ} ) If the inter-frequency/inter-RAT cell signal quality (Squal) is greater than the threshold Thresh _{X , LowQ -} during a specific time Treselection _RAT (Squal> Thresh _X,LowQ During a time interval Treselection _RAT ), the UE may perform reselection to a corresponding inter-frequency/inter-RAT cell.

Article 5 action:

If the terminal cannot perform the fourth operation, the terminal may perform the fifth operation.

One second after the UE has camped on the current serving cell, the reception level (Srxlev) of the current serving cell is less than the thresholds Thresh _{Serving and LowP} (Srxlev <Thresh _{Serving , LowP} ) and inter-frequency/inter-RAT cell reception If the level (Srxlev) is greater than the threshold Thresh _{X , LowQ -} during a specific time Treselection _RAT (Srxlev> Thresh _X,LowP During a time interval Treselection _RAT ), the UE may perform reselection to a corresponding inter-frequency/inter-RAT cell.

Here, the fourth or fifth operation for the inter-frequency cell of the UE is included in thresholds (Thresh _{Serving , LowQ} , Thresh _{Serving , LowP} ) included in SIB2 broadcast in the serving cell and SIB4 broadcast in the serving cell. The inter-frequency cell may be performed based on signal quality (Squal), reception level (Srxlev), thresholds (Threh _{X , LowQ ,} Thresh _{X , LowP} ), _{and Treselection RAT} . The fourth or fifth operation for the inter-RAT cell of the terminal is included in thresholds (Thresh _{Serving , LowQ} , Thresh _{Serving, LowP} ) included in SIB2 broadcast in the serving cell and _SIB5 broadcast in the serving cell. The inter-RAT cell may be performed based on signal quality (Squal), reception level (Srxlev), thresholds (Thresh _{X, LowQ} , Thresh _{X , LowP} ), _{and Treselection RAT} . For example, Q _{qualmin in} SIB4 Value or Q _rxlevmin Values are included, and based on this, signal quality (Squal) or reception level (Srxlev) of an inter-frequency cell may be derived.

In step 2g-30, the UE receives system information (for example, MIB and/or SIB1) broadcast in the cell before finally reselecting a candidate target cell based on priority in steps 2g-25. To receive and camp-on the cell, the signal of the cell can be measured (2g-30).

That is, based on MIB and/or SIB1 broadcast from a candidate target cell, if the state of the corresponding cell is not indicated as prohibited, and is not considered to be prohibited (cell status "barred" is not indicated or not to be treated as if the cell status is "barred"), and the cell selection criterion (S-criterion) is satisfied by deriving the reception level (Srxlev) and reception quality (Squal) of the corresponding cell based on the received SIB1 (Srxlev> 0 AND Squal >0), and camp-on to the cell to reselect.

FIG. 2H illustrates a process of reselecting an intra-frequency/inter-frequency cell having the same priority as the frequency of a serving cell when the UE is in RRC idle mode or RRC inactive mode, according to an embodiment of the present invention. It is one drawing.

The UE 2h-01 in the RRC idle mode or the RRC deactivated mode may perform a series of operations while camping on the serving cell (2h-05).

In step 2h-10, the UE in the RRC idle mode or RRC inactive mode may receive system information broadcast by the base station of the serving cell. At this time, the RRC idle mode or RRC deactivated mode terminal may not receive system information broadcast by the base station of the neighboring cell. System information may be divided into a master information block (MIB) and system information blocks (System Information Blocks, SIBs). Additionally, the system information blocks may be referred to by dividing them into SI messages (eg, SIB2, SIB3, SIB4, or SIB5) except SIB1 and SIB1. The RRC idle mode or RRC deactivation mode terminal may receive and read system information (eg, MIB or SIB1 or SIB2) broadcast by the base station of the corresponding cell before camping on the serving cell. For reference, MIB and SIB1 may be system information commonly applied to all terminals. SIB2 may be system information commonly applied to a UE in an RRC idle mode or an RRC deactivated mode to reselect intra-frequency, inter-frequency, and inter-RAT cells. SIB3, SIB4, and SIB5 may include information necessary for a UE in RRC idle mode or RRC deactivated mode to reselect a cell.

SIB1 may include parameters such as minimum reception level or minimum signal quality or threshold used when determining whether to measure a serving cell signal, and this information may be applied cell-specific. SIB2, SIB3, SIB4, and SIB5 may include information about parameters such as minimum reception level or minimum signal quality or threshold used when determining whether to measure a neighbor cell signal. Specifically, SIB2 includes common information for intra-frequency, inter-frequency, and inter-RAT cell reselection, SIB3 includes information for intra-frequency cell reselection only, and SIB4 inter-frequency cell reselection. Only information is included, and SIB5 may include information only for inter-RAT cell reselection.

In steps 2h-15, the RRC idle mode or RRC deactivation mode terminal wakes up every discontinuous reception (DRX) cycle to determine the absolute signal strength of the serving cell (Reference Signal Received Power (RSRP, Q _rxlevmeas ) and relative signal quality (Reference Signal Received) Quality (RSRQ), Q _qualmeas ) can be measured (2h-15) The operation of the proposed terminal when deriving a measurement quantity of a cell is as follows.

One. In the case of selecting a cell performing a plurality of beam operations (For cell selection in multi-beam operations), a measurement value of the cell may be derived by a terminal implementation.

2. When re-selecting a cell performing multiple beam operations (For cell reselection in multi-beam operations), the measured value of the cell may be derived based on a plurality of beams corresponding to the same cell based on SSB, It can be one of the following:

A. If nrofSS - BlocksToAverage or absThreshSS - BlocksConsolidation is not set in SIB2, or the measured value of the beam with the strongest signal is less than or equal to absThreshSS -BlocksConsolidation set.

i. The measured value of the beam with the strongest signal can be derived as the measured value of the cell.

B. If not,

i. Average linear power values up to nrofSS - BlocksToAverage among the measured values of the largest beam larger than the set absThreshSS - BlocksConsolidation can be derived as the measured values of the cell (derive a cell measurement quantity as the linear average of the power values up to nrofSS - BlocksToAverage of highest beam measurement quantity values above absThreshSS - BlocksConsolidation).

The UE may calculate the reception level (Srxlev) and reception quality (Sqaul) of the serving cell using the parameters received from SIB1 through these measurement values. The UE may determine whether to perform neighbor cell measurement for cell reselection by comparing the calculated values with threshold values. The reception level Srxlev and the reception quality Sqaul of the serving cell may be determined through Equation 1 above.

In order to minimize battery consumption, the RRC idle mode or RRC deactivation mode terminal does not always measure neighbor cells, but determines whether to perform neighbor cell measurement based on a measurement rule. It can be judged whether or not (2h-20). At this time, the RRC idle mode or RRC deactivation mode terminal does not receive the system information broadcasted by the base station of the neighboring cell, and can perform neighboring cell measurement using the system information broadcasted by the serving cell currently camping on. If the reception level (Srxlev) and reception quality (Squal) of the current serving cell measured in steps 2h-15 becomes smaller than the threshold (Srxlev <= S _IntraSearchP and Squal <= S _IntraSeachQ ), RRC idle mode or RRC deactivation The mode terminal can measure neighboring cells using the same frequency as the serving cell (2h-20). That is, the signal quality (Squal) or reception level (Srxlev) of neighboring cells using the same frequency as the serving cell is derived based on SIB2 or SIB3 broadcast from the serving cell (Equation 1 is applied).

For reference, information on threshold values for S _IntraSearchP and S _IntraSearchQ is included in SIB2. In addition, for inter-frequency/inter-RAT cells having a higher priority than the frequency of the current serving cell, neighbor cell measurement can be performed regardless of the quality of the serving cell (2h-20). That is, the signal quality (Squal) or reception level (Srxlev) of inter-frequency cells having a higher priority than the frequency of the serving cell is derived based on SIB4 broadcast from the serving cell (Equation 1 is applied), and the frequency of the serving cell The signal quality (Squal) or reception level (Srxlev) of inter-RAT cells having higher priority may be derived based on SIB5 broadcast from the serving cell (Equation 1 applied). Also, for inter-frequency cells having the same or lower priority than the frequency of the serving cell or inter-RAT frequency cells having a lower priority than the frequency of the serving cell, the reception level (Srxlev) of the current serving cell measured in steps 2h-15. When the and the reception quality (Squal) becomes smaller than the threshold (Srxlex <= S _{nonIntraSearchP} and Squal <= S _intraSearchQ ), the RRC idle mode or RRC deactivation mode UE is configured with neighboring cells or serving cells that use a different frequency from the serving cell. Cells using other radio access technologies can be measured (2h-20). That is, the signal quality (Squal) or reception level (Srxlev) of the inter-frequency cell(s) having a priority equal to or lower than the frequency of the serving cell is derived based on SIB4 broadcast from the serving cell (Equation 1 applied) ), the signal quality (Squal) or reception level (Srxlev) of the inter-RAT cell(s) having a priority lower than the frequency of the serving cell may be derived based on SIB5 broadcast from the serving cell (Equation 1 applied). . For reference, the threshold information for S _{nonIntraSearchP} and S _{nonIntraSearchQ} is included in SIB2.

The RRC idle mode or RRC deactivation mode UE may perform a cell re-selection evaluation process based on priority (CellReselectionPriority) based on the measured values (2h-20) for neighboring cells (2h) -25). The priority information is included in the system information (SIB1, SIB2, SIB3, SIB4, SIB5) broadcast in the serving cell or included in the RRCRelease message received when switching to RRC idle mode or RRC inactive mode.

The proposed UE operation for the re-selection evaluation procedure of the intra-frequency/inter-frequency cell having the same priority as the current serving cell frequency is as follows.

- Through the above Equation 1, ranking can be performed for all cells that satisfy the cell selection criterion (Selllev> 0 AND/OR Squal> 0) (2h-25).

A. At this time, for cells that satisfy the above conditions, the current serving cell and surrounding cells through the average absolute signal strength (averaged RSRP) based on the cell ranking criterion (Cell-raking criterion, R-Criterion) through Equation 2 described above You can perform ranking for.

The terminal may perform a cell reselection evaluation procedure based on one or more of the following methods.

- If rangeToBestCell is not set in SIB2 broadcast from the serving cell,

A. If the rank of the neighboring cell is greater than the rank of the serving cell (R _n > R _s ) from Equation 2 during a specific time Treselection _RAT , the optimal cell among the neighboring cells ( highest ranked cell) (2h-30).

- If rangeToBestCell is set in SIB2 broadcast from the serving cell, and nrofSS-BlocksToAverage is not set in SIB2 and/or SIB4 broadcast in the serving cell (nrofSS-BlocksToAverage is absent in SIB2 and/or SIB2),

A. If the rank of the neighboring cell obtained from Equation 2 during the Treselection _RAT at a specific time is greater than the rank of the serving cell (R _n > R _s ) and exceeds 1 second after camp-on to the current serving cell, the optimal among the neighboring cells You can camp on the cell (2h-35).

- If rangeToBestCell is set in SIB2 broadcast from the serving cell, and nrofSS-BlocksToAverage is set in SIB2 and/or SIB4 broadcast in the serving cell (nrofSS-BlocksToAverage is present in SIB2 and/or SIB2),

A. When there are more cells than nrofSS-BlocksToAverage among the cells having R values in the rangeToBestCell of the R value of the highest ranked cell, the number of beams greater than absThreshSS-BlocksConsolidation,

i. If the rank of the neighboring cell obtained from Equation 2 during the Treselection _RAT at a specific time is greater than the rank of the serving cell (R _n > R _s ) and exceeds 1 second after camp-on to the current serving cell, the optimal cell among the neighboring cells You can camp on (2h-35).

- If rangeToBestCell is set in SIB2 broadcast from the serving cell,

A. Among cells having an R value belonging to rangeToBestCell of the R value of the cell with the highest rank, the cell having the highest ratio of the number of beams greater than absThreshSS-BlocksConsolidation in the total number of beams per cell (cell with the highest ratio of number of beams) Above the threshold (ie absThreshSS-BlocksConsolidation) to the total number of beams among the cells whose R value is within rangeToBestCell of the R value of the highest ranked cell can be reselected. The new cell is better than the serving cell during a specific time TreselectionRAT (the new cell is better than the serving cell during a time interval Treselection _RAT ), and the UE performs reselection with a new cell when the current serving cell exceeds the camp-on limit for 1 second. can do.

In step 2h-50, before finally reselecting a candidate target cell, system information (for example, MIB and/or SIB1) broadcast on the cell is received, and the corresponding cell is camped on. The signal of the cell can be measured. That is, based on MIB and/or SIB1 broadcast from a candidate target cell, if the state of the corresponding cell is not indicated as prohibited, and is not considered to be prohibited (cell status "barred" is not indicated or not to be treated as if the cell status is "barred"), and the cell selection criterion (S-criterion) is satisfied by deriving the reception level (Srxlev) and reception quality (Squal) of the corresponding cell based on the received SIB1 (Srxlev> 0 AND Squal >0), and camp-on to the corresponding cell to finally select it.

2i is a block diagram showing the internal structure of a terminal according to an embodiment of the present invention.

Referring to the drawings, the terminal includes a radio frequency (RF) processor 2i-10, a baseband processor 2i-20, a storage 2i-30, and a controller 2i-40. .

The RF processor 2i-10 performs a function for transmitting and receiving a signal through a wireless channel such as band conversion and amplification of the signal. That is, the RF processor 2i-10 up-converts the baseband signal provided from the baseband processor 2i-20 to an RF band signal, transmits it through an antenna, and transmits an RF band signal through the antenna. Downconvert to baseband signal. For example, the RF processing unit 2i-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), and an analog to digital converter (ADC). Can be. In the figure, only one antenna is shown, but the terminal may have multiple antennas. In addition, the RF processing unit 2i-10 may include a plurality of RF chains. Furthermore, the RF processing unit 2i-10 may perform beamforming. For the beamforming, the RF processor 2i-10 may adjust the phase and magnitude of each of signals transmitted and received through multiple antennas or antenna elements. In addition, the RF processing unit may perform MIMO, and may receive multiple layers when performing the MIMO operation.

The baseband processor 2i-20 performs a conversion function between a baseband signal and a bit stream according to a physical layer standard of the system. For example, when transmitting data, the baseband processing unit 2i-20 generates complex symbols by encoding and modulating a transmission bit stream. In addition, upon receiving data, the baseband processing unit 2i-20 restores the received bit stream through demodulation and decoding of the baseband signal provided from the RF processing unit 2i-10. For example, in the case of conforming to the orthogonal frequency division multiplexing (OFDM) method, when transmitting data, the baseband processor 2i-20 encodes and modulates a transmission bit stream to generate complex symbols, and the complex symbols are subcarriers. After mapping to, OFDM symbols are constructed through inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processing unit 2i-20 divides the baseband signal provided from the RF processing unit 2i-10 into OFDM symbol units and maps them to subcarriers through a fast Fourier transform (FFT). After restoring the received signals, the received bit stream is reconstructed through demodulation and decoding.

The baseband processor 2i-20 and the RF processor 2i-10 transmit and receive signals as described above. Accordingly, the baseband processor 2i-20 and the RF processor 2i-10 may be referred to as a transmitter, a receiver, a transceiver, or a communicator. Furthermore, at least one of the baseband processor 2i-20 and the RF processor 2i-10 may include a plurality of communication modules to support a plurality of different radio access technologies. Further, at least one of the baseband processor 2i-20 and the RF processor 2i-10 may include different communication modules to process signals of different frequency bands. For example, the different radio access technologies may include a wireless LAN (eg, IEEE 802.11), a cellular network (eg, LTE), and the like. In addition, the different frequency bands may include a super high frequency (SHF) band (eg, 2.NRHz, NRhz) and a millimeter wave (mmband) band (eg, 60 GHz).

The storage unit 2i-30 stores data such as a basic program, an application program, and setting information for the operation of the terminal. In particular, the storage unit 2i-30 may store information related to a second access node that performs wireless communication using a second wireless access technology. Then, the storage unit 2i-30 provides data stored at the request of the control unit 2i-40.

The control unit 2i-40 controls overall operations of the terminal. For example, the control unit 2i-40 transmits and receives signals through the baseband processing unit 2i-20 and the RF processing unit 2i-10. Further, the control unit 2i-40 writes and reads data in the storage unit 2i-40. To this end, the control unit 2i-40 may include at least one processor. For example, the controller 2i-40 may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls an upper layer such as an application program.

2J is a block diagram showing the configuration of an NR base station according to an embodiment of the present invention.

As shown in the figure, the base station includes an RF processing unit 2j-10, a baseband processing unit 2j-20, a backhaul communication unit 2j-30, a storage unit 2j-40, and a control unit 2j-50. It is configured to include.

The RF processor 2j-10 performs a function for transmitting and receiving a signal through a wireless channel such as band conversion and amplification of the signal. That is, the RF processor 2j-10 up-converts the baseband signal provided from the baseband processor 2j-20 to an RF band signal, transmits it through an antenna, and transmits an RF band signal through the antenna. Downconvert to baseband signal. For example, the RF processor 2j-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. In the figure, only one antenna is shown, but the first access node may include multiple antennas. Also, the RF processing unit 2j-10 may include multiple RF chains. Furthermore, the RF processing unit 2j-10 may perform beamforming. For the beamforming, the RF processor 2j-10 may adjust the phase and magnitude of each of signals transmitted and received through a plurality of antennas or antenna elements. The RF processing unit may perform a downlink MIMO operation by transmitting one or more layers.

The baseband processing unit 2j-20 performs a conversion function between a baseband signal and a bit stream according to a physical layer standard of the first wireless access technology. For example, during data transmission, the baseband processor 2j-20 generates complex symbols by encoding and modulating the transmission bit stream. In addition, when receiving data, the baseband processing unit 2j-20 restores the received bit stream through demodulation and decoding of the baseband signal provided from the RF processing unit 2j-10. For example, according to the OFDM scheme, when transmitting data, the baseband processor 2j-20 generates complex symbols by encoding and modulating a transmission bit stream, mapping the complex symbols to subcarriers, and then IFFT OFDM symbols are constructed through arithmetic and CP insertion. In addition, when receiving data, the baseband processing unit 2j-20 divides the baseband signal provided from the RF processing unit 2j-10 into OFDM symbol units and restores signals mapped to subcarriers through FFT calculation. After that, the received bit stream is restored through demodulation and decoding. The baseband processor 2j-20 and the RF processor 2j-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 2j-20 and the RF processing unit 2j-10 may be referred to as a transmission unit, a reception unit, a transmission/reception unit, a communication unit, or a wireless communication unit.

The backhaul communication unit 2j-30 provides an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 2j-30 converts a bit stream transmitted from the main station to another node, for example, an auxiliary base station, a core network, etc., into a physical signal, and bites the physical signal received from the other node. Convert to heat.

The storage unit 2j-40 stores data such as a basic program, an application program, and setting information for the operation of the main station. In particular, the storage unit 2j-40 may store information on bearers allocated to the connected terminal, measurement results reported from the connected terminal, and the like. In addition, the storage unit 2j-40 may store information serving as a criterion for determining whether to provide or stop multiple connections to the terminal. Then, the storage unit 2j-40 provides data stored at the request of the control unit 2j-50.

The control unit 2j-50 controls overall operations of the main station. For example, the control unit 2j-50 transmits and receives signals through the baseband processing unit 2j-20 and the RF processing unit 2j-10 or through the backhaul communication unit 2j-30. Further, the control unit 2j-50 writes and reads data in the storage unit 2j-40. To this end, the control unit 2j-50 may include at least one processor.

Claims (1)

In the control signal processing method in a wireless communication system,
Receiving a first control signal transmitted from a base station;
Processing the received first control signal; And
And transmitting a second control signal generated based on the processing to the base station.

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