KR20180137385A - Method and apparatus for rapidly reporting frequency measurement results in next generation mobile communication system - Google Patents

Abstract

The present disclosure relates to a communication method for converging a fifth generation (5G) communication system for supporting a higher data rate beyond a fourth generation (4G) system with a technology for Internet of Things (IoT), and a system thereof. The present disclosure can be applied to an intelligent service based on a 5G communication technology and an IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security-and-safety services. In addition, according to the present invention, disclosed is a method for a terminal to rapidly report a frequency measurement result in a next generation mobile communication system. To this end, a method for processing a control signal in a wireless communication system includes the steps of: receiving a first control signal transmitted from a base station; processing the received first control signal; and transmitting a second control signal generated based on the processing to the base station.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for quickly reporting a frequency measurement result in a next generation mobile communication system,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a method and an apparatus for enabling a terminal to quickly report a frequency measurement result in a next generation mobile communication system.

Efforts are underway to develop an improved 5G or pre-5G communication system to meet the growing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, a 5G communication system or a pre-5G communication system is called a system after a 4G network (Beyond 4G network) communication system or after a LTE system (Post LTE). To achieve a high data rate, 5G communication systems are being considered for implementation in very high frequency (mmWave) bands (e.g., 60 gigahertz (60GHz) bands). In order to mitigate the path loss of the radio wave in the very high frequency band and to increase the propagation distance of the radio wave, in the 5G communication system, beamforming, massive MIMO, full-dimension MIMO (FD-MIMO ), Array antennas, analog beam-forming, and large scale antenna technologies are being discussed. In order to improve the network of the system, the 5G communication system has developed an advanced small cell, an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network, (D2D), a wireless backhaul, a moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation Have been developed. In addition, in the 5G system, the Advanced Coding Modulation (ACM) scheme, Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), the advanced connection technology, Filter Bank Multi Carrier (FBMC) (non-orthogonal multiple access), and SCMA (sparse code multiple access).

On the other hand, the Internet is evolving into an Internet of Things (IoT) network in which information is exchanged between distributed components such as objects in a human-centered connection network where humans generate and consume information. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with cloud servers, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired / wireless communication, network infrastructure, service interface technology and security technology are required. In recent years, sensor network, machine to machine , M2M), and MTC (Machine Type Communication). In the IoT environment, an intelligent IT (Internet Technology) service can be provided that collects and analyzes data generated from connected objects to create new value in human life. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, and advanced medical service through fusion of existing information technology . ≪ / RTI >

Accordingly, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as a sensor network, a machine to machine (M2M), and a machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antennas It is. The application of the cloud RAN as the big data processing technology described above is an example of the convergence of 5G technology and IoT technology.

There is a need for a method and an apparatus for enabling a terminal to quickly report a frequency measurement result in a next generation mobile communication system according to recent developments of LTE (Long Term Evolution) and LTE-Advanced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mobile communication system in which a base station quickly sets up a carrier aggregation (CA) or a dual connectivity (DC) technology to support a service having a high data rate and a low transmission delay in a next generation mobile communication system I need to do it. However, in order to set the above techniques to the UE, the frequency measurement result of the UE is needed. Therefore, we propose a method to receive the frequency measurement result of the terminal quickly.

It is a further object of the present invention to provide a method and apparatus for supporting sequential forwarding of packets received from a PDCP layer to an upper layer in a next generation mobile communication system because the RLC layer does not support sequential forwarding of received packets, If retransmission can be requested, this should also be considered. If the higher layers support sequential forwarding functions, it may not be necessary to support sequential forwarding functions in the PDCP layer as well. Therefore, it is necessary to support the operation modes of the PDCP layer in consideration of various cases.

It is still another object of the present invention to provide a method of determining a connection state of each base station when a terminal uses different or same radio access technology (RAT) And a method for processing the same.

According to an aspect of the present invention, there is provided a method of processing a control signal in a wireless communication system, the method 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 process to the base station.

According to an embodiment of the present invention, the present invention proposes a method for allowing a terminal to quickly report a measurement result of a peripheral frequency to a base station in a next generation mobile communication system, So that it can be set.

 In addition, according to another embodiment of the present invention, various modes of the PDCP layer are proposed to support various functions required in the next generation mobile communication system, and an operation procedure of the modes and methods of setting each mode So that various functions can be supported in the next generation mobile communication system.

In addition, according to another embodiment of the present invention, when a communication error occurs with each base station, the terminal can recover the connection by determining the error.

1A is a diagram showing a structure of an LTE system to which the present invention can be applied.
1B is a diagram illustrating a wireless protocol structure in an LTE system to which the present invention can be applied.
1C is a diagram illustrating a structure of a next generation mobile communication system to which the present invention can be applied.
1D is a diagram illustrating a wireless protocol structure of a next generation mobile communication system to which the present invention can be applied. .
FIG. 1E is a block diagram illustrating a first embodiment in which a UE can perform an early measurement in a next generation mobile communication system and can quickly report a frequency measurement result (fast measurement report). FIG.
FIG. 1F shows a first embodiment in which the UE can perform early measurement in a next generation mobile communication system and can quickly report a frequency measurement (fast measurement report). FIG.
FIG. 1G shows a first to third embodiments in which a UE can perform early measurement in a next generation mobile communication system and can quickly report a frequency measurement (fast measurement report). FIG.
FIG. 1H is a diagram illustrating a terminal operation in which the UE performs an early measurement and a fast measurement report in a next generation mobile communication system according to the present invention.
FIG. 1I illustrates a structure of a terminal to which an embodiment of the present invention can be applied.
1J illustrates a block diagram of a TRP in a wireless communication system to which an embodiment of the present invention may be applied.
2A is a diagram showing a structure of an LTE system to which the present invention can be applied.
2B is a diagram illustrating a wireless protocol structure in an LTE system to which the present invention can be applied.
2C is a diagram illustrating a structure of a next generation mobile communication system to which the present invention can be applied.
FIG. 2D is a diagram illustrating a wireless protocol structure of a next generation mobile communication system to which the present invention can be applied.
FIG. 2E is a diagram for explaining a procedure for establishing a connection with a network by switching a terminal from the RRC idle mode to the RRC connected mode (RRC connected mode) in the present invention.
FIG. 2F is a diagram illustrating a PUSH-based window operation that can be performed in the PDCP layer.
FIG. 2G is a diagram illustrating a PULL-based window operation that can be performed in the PDCP layer.
2H is a diagram illustrating a UE operation in which a UE receives PDCP layer setup information and determines a PDCP mode and operates according to the PDCP layer setup information.
FIG. 2I illustrates a structure of a terminal to which an embodiment of the present invention can be applied.
2J illustrates a block diagram of a TRP in a wireless communication system to which an embodiment of the present invention may be applied.
2K illustrates a reception window operation in the PDCP layer of the next generation mobile communication system proposed in the present invention.
FIG. 3A is a diagram showing a structure of a LTE system as a reference for explaining the present invention.
FIG. 3B is a diagram illustrating a wireless protocol structure of an LTE system for the purpose of explanation of the present invention.
3C is a diagram for explaining the concept of multiple connections in LTE and NR.
FIG. 3D is a diagram illustrating a message flow between a terminal and a base station when the present invention is applied.
3E is a diagram illustrating an example of the operation sequence of the terminal when the present invention is applied.
FIG. 3F is a diagram illustrating an example of the configuration of a terminal according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

≪ Embodiment 1 >

Hereinafter, the operation principle of the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

A term used for identifying a connection node used in the following description, a term referring to network entities, a term referring to messages, a term indicating an interface between network objects, a term indicating various identification information Etc. are illustrated for convenience of explanation. Therefore, the present invention is not limited to the following terms, and other terms referring to objects having equivalent technical meanings can be used.

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

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

1A, a radio access network of an LTE system includes an Evolved Node B (hereinafter, referred to as an ENB, a Node B or a base station) 1a-05, 1a-10, 1a-15 and 1a-20, MME (Mobility Management Entity) 1a-25, and Serving-Gateway (S-GW) 1a-30. A user equipment (hereinafter referred to as UE or UE) 1a-35 accesses an external network through the ENBs 1a-05 to 1a-20 and the S-GW 1a-30.

In FIG. 1A, the ENBs 1a-05 to 1a-20 correspond to the existing node B of the UMTS system. The ENB is connected to the UEs 1a-35 over a radio channel and plays a more complex role than the existing NodeB. In the LTE system, since all user traffic including a real-time service such as Voice over IP (VoIP) over the Internet protocol is serviced through a shared channel, status information such as buffer status, available transmission power status, And the ENBs 1a-05 through 1a-20 take charge of the scheduling. One ENB normally controls a plurality of cells. For example, in order to realize a transmission rate of 100 Mbps, an LTE system uses Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology, for example, at a bandwidth of 20 MHz. In addition, Adaptive Modulation and Coding (AMC) scheme is used to determine a modulation scheme and a channel coding rate in accordance with a channel state of a UE. The S-GW 1a-30 is a device for providing a data bearer and generates or removes a data bearer under the control of the MME 1a-25. The MME is a device that performs various control functions as well as a mobility management function for a terminal, and is connected to a plurality of base stations.

1B is a diagram illustrating a wireless protocol structure in an LTE system to which the present invention can be applied.

Referring to FIG. 1B, the wireless protocol of the LTE system includes PDCP (Packet Data Convergence Protocol 1b-05, 1b-40), RLC (Radio Link Control 1b-10, Control 1b-15, 1b-30). Packet Data Convergence Protocol (PDCP) 1b-05, 1b-40 is responsible for IP header compression / decompression. The main functions of the 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 function (PDCP SDUs at handover and for split bearers in DC, PDCP PDUs at PDCP data-recovery procedure, for RLC AM)

- Ciphering and deciphering function

- Timer-based SDU discard in uplink.

Radio Link Control (RLC) 1b-10 and 1b-35 reconfigures a PDCP PDU (Packet Data Unit) to an appropriate size to perform an ARQ operation or the like. The main functions of the RLC are summarized as follows.

- 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 (only for AM data transfer)

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

- RLC re-establishment function (RLC re-establishment)

The MACs 1b-15 and 1b-30 are connected to a plurality of RLC layer devices arranged in a terminal, multiplex RLC PDUs into MAC PDUs, and demultiplex RLC PDUs from MAC PDUs. The main functions of the MAC are summarized as follows.

- Mapping between logical channels and transport channels.

- 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 (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification (MBMS service identification)

- Transport format selection function (Transport format selection)

- Padding function

The physical layers 1b-20 and 1b-25 channel-code and modulate the upper layer data, transmit them to the wireless channel by making OFDM symbols, demodulate the OFDM symbols received through the wireless channel, channel-decode the data, .

1C is a diagram illustrating a structure of a next generation mobile communication system to which the present invention can be applied.

1C, a radio access network of a next generation mobile communication system (hereinafter referred to as NR or 5G) includes a next-generation base station (NR gNB or NR base station) 1c-10 and an NR CN 1c -05, New Radio Core Network). A user terminal (NR UE or UE) 1c-15 accesses the external network through NR gNB 1c-10 and NR CN 1c-05.

1C, the NR gNB (1c-10) corresponds to the eNB (Evolved Node B) of the existing LTE system. The NR gNB is connected to the NR UE (1c-15) via a radio channel and can provide a superior service than the existing Node B. In the next generation mobile communication system, since all user traffic is served through a shared channel, a device for collecting and scheduling state information such as buffer status, available transmission power state, and channel state of UEs is required. (1c-10). One NR gNB typically controls multiple cells. In order to realize high-speed data transmission in comparison with the current LTE, it can have an existing maximum bandwidth or more, and additionally, beam-forming technology can be applied by using Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology . In addition, Adaptive Modulation and Coding (AMC) scheme is used to determine a modulation scheme and a channel coding rate in accordance with a channel state of a UE. The NR CN (1c-05) performs functions such as mobility support, bearer setup, and QoS setup. The NR CN is a device that performs various control functions as well as a mobility management function for a terminal, and is connected to a plurality of base stations. Also, the next generation mobile communication system can be interworked with the existing LTE system, and the NR CN is connected to the MME 1c-25 through a network interface. The MME is connected to the eNB 1c-30, which is an existing base station.

1D is a diagram illustrating a wireless protocol structure of a next generation mobile communication system to which the present invention can be applied. .

1D, a radio protocol of the next generation mobile communication system includes NR PDCPs 1d-05 and 1d-40, NR RLCs 1d-10 and 1d-35, and NR MACs 1d-15 and 1d- , 1d-30). The main functions of the NR PDCPs (1d-05, 1d-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

- Order reordering function (PDCP PDU reordering for reception)

- Duplicate detection of lower layer SDUs

- Retransmission of PDCP SDUs

- Ciphering and deciphering function

- Timer-based SDU discard in uplink.

In the above, the reordering function of the NR PDCP apparatus refers to a function of rearranging PDCP PDUs received in a lower layer in order based on a PDCP SN (sequence number), and transmitting data to an upper layer in the order of rearrangement And may include a function of directly transmitting PDCP PDUs without considering the order, and may include a function of recording lost PDCP PDUs by rearranging the order, and may include a status report for lost PDCP PDUs To the transmitting side, and may include a function of requesting retransmission of lost PDCP PDUs.

The main functions of the NR RLCs (1d-10, 1d-35) may include some of the following functions.

- 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 discard function (RLC SDU discard)

- RLC re-establishment function (RLC re-establishment)

The in-sequence delivery function of the NR RLC apparatus refers to a function of delivering RLC SDUs received from a lower layer to an upper layer in order, and an original RLC SDU is divided into a plurality of RLC SDUs And reassembling and delivering the received RLC PDUs when the RLC PDUs are received. The RLC PDUs may include a function of rearranging received RLC PDUs based on a RLC SN (sequence number) or a PDCP SN (sequence number) May include the capability to record lost RLC PDUs and may include the ability to send a status report for lost RLC PDUs to the sender and may include the ability to request retransmission of lost RLC PDUs And may include a function of transferring only the RLC SDUs up to the lost RLC SDU to the upper layer in order of the lost RLC SDU if there is a lost RLC SDU, If all the RLC SDUs received up to the present time have been expired, the RLC SDUs may be transmitted to the upper layer in order, To the upper layer in order. In addition, the RLC PDUs may be processed in the order of receiving the RLC PDUs (in the order of arrival of the sequence number and the sequence number), and may be transmitted to the PDCP device in an out-of-sequence delivery manner. It is possible to receive segments that are stored in the buffer or to be received at a later time, reconfigure the received segments into one complete RLC PDU, and transmit the segmented PDCP PDCP device to the PDCP device. The NR RLC layer may not include a concatenation function and may perform the function in the NR MAC layer or in place of the NR MAC layer multiplexing function.

The out-of-sequence delivery function of the NR RLC apparatus refers to a function of delivering RLC SDUs received from a lower layer directly to an upper layer regardless of order, SDUs, and reassembling and delivering the RLC PDUs when they are received. The RLC PDU includes a function of storing RLC SN or PDCP SN of the received RLC PDUs and recording the lost RLC PDUs by arranging the order .

The NR MACs (1d-15, 1d-30) may be connected to various NR RLC layer devices configured in one UE, and the main function of the NR MAC may include some of the following functions.

- Mapping between logical channels and transport channels.

- Multiplexing / demultiplexing of MAC SDUs

- Scheduling information reporting function

- HARQ (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification (MBMS service identification)

- Transport format selection function (Transport format selection)

- Padding function

The NR PHY layers 1d-20 and 1d-25 channel-code and modulate the upper layer data, transmit them in a wireless channel by making them into OFDM symbols, or demodulate and channel-decode OFDM symbols received through a wireless channel, Can be performed.

In the LTE system, the UE performs frequency measurement while performing a cell reselection procedure in an RRC idle mode. However, it does not report the frequency measurement results to the network separately. When the UE performs a cell reselection procedure to find a suitable cell and camps on, and then transitions to the RRC connection mode by performing an RRC connection establishment procedure, the BS notifies the terminal of certain frequencies (for example, frequency List) or which frequency bands to measure, which order to set for each frequency and how to measure them, what filtering method to use to measure the frequency strength (eg, L1 filtering, (Eg, L2 filtering, L3 filtering, or what counts with which method to measure, etc.), what events or conditions to start measuring when measuring frequency, current serving cell Frequency), what frequency to measure and what frequency or frequency of the event What can that will set out the current serving cell when compared to (or currently camping and frequency) I want to see the frequency must satisfy certain criteria or conditions, whether to report the frequency measurements in each certain period. The terminal measures the frequencies according to the frequency setting set as described above at the base station, and reports the frequency measurement results to the base station according to the event or condition. The base station can determine whether to apply the frequency aggregation technique or the dual connectivity technique to the UE using the frequency measurement result received from the UE.

In the present invention, methods for starting a frequency measurement before a UE transits to an RRC connection mode in a next generation mobile communication system and reporting the measured result to the RRC connection mode quickly or after entering the RRC connection mode are proposed.

The proposed methods can be very useful for setting a fast frequency coherence technique or a dual access technique in an environment in which small cells are arranged in a macro cell.

FIG. 1E is a block diagram illustrating a first embodiment of the present invention in which a UE can perform early measurement in a next generation mobile communication system and can quickly report a frequency measurement result (fast measurement report). FIG.

A terminal capable of performing early measurement and reporting a fast measurement report in the embodiment 1-1 may be one or more of the following cases.

One. All terminals supporting fast frequency measurement and fast frequency measurement report method

2. RRC deactivation mode A terminal (for example, as an indicator) designated to be able to perform fast frequency measurement and quick frequency measurement result report when the base station transits the terminal from the RRC connection mode to the RRC deactivation mode in the RRC message.

3. In a terminal in which MO (Mobile Oriented) data is generated, i.e., a terminal in which data to be transmitted in uplink exists

4. (E.g., mobile terminated) data is generated in the network (i.e., downlink data is generated), the paging message is received from the network, and the paging message is used to perform fast frequency measurement and quick frequency measurement report, As an indicator).

5. If the amount of data to be transmitted to the RRC idle mode terminal or the RRC deactivated mode terminal is greater than a predetermined threshold, the threshold value may be set as an RRC message in the base station or broadcast in the system information. The RRC message may be a message that transits from the RRC connection mode to the RRC idle mode or the RRC deactivation mode, or an RRC message that the UE can receive when establishing the previous connection.

6. RRC deactivation mode When a base station transitions from the RRC connection mode to the RRC deactivation mode in the RRC message, the base station can perform fast frequency measurement and report a fast frequency measurement result when it is in a specific paging area And the terminal in the paging area.

The terminal 1e-05 in the RRC idle mode or the RRC inactive mode in FIG. 1e can not receive the paging message or receive the paging message for a predetermined reason (for example, To update the RRC connection mode, etc.). Accordingly, the UE can transmit the preamble to the Node B as a first procedure of the random access (1e-10). If the base station successfully receives the UE's promamble, it can send a random access response (RAR) to the UE. At this time, the BS may transmit an indication indicating the fast frequency measurement to the UE in the random access response. In addition, it is possible to determine which frequencies or certain frequency bands are to be measured in the random access response message (for example, a frequency list), a priority order for each frequency, (Eg, L1 filtering, L2 filtering, L3 filtering, or what factors are used to measure with some calculation method), and what events or conditions It is therefore important to decide whether to start the measurement, what criteria to measure relative to the current serving cell (or the current camp-on frequency), what frequency event to report according to which event or condition, The frequency that is currently camped on) should be met. And an early measurement setup information such as the frequency measurement result to be reported every cycle.

Alternatively, the base station broadcasts the frequency measurement-related setting information in the system information, and in the random access response message, the base station may include only an indicator for instructing quick frequency measurement.

Alternatively, the base station may reuse the frequency measurement related setting information (e.g., frequency list, frequency priority, and the like) measured at the time of cell reselection in the RRC idle mode to the UE. In the random access response message, It is possible to instruct the terminal to include only the indicator indicating the terminal.

The conditions for starting the frequency measurement when the UE performs early measurement may be as follows.

One. When entering RRC idle mode or RRC disable mode

2. When the frequency measurement related setting information is received

3. When the fast frequency measurement indicator is received and confirmed in the RAR message,

4. When a random access procedure transmits a preamble, that is, when a random access procedure is started

5. When the amount of data to be transmitted from the terminal exceeds a predetermined threshold value

According to one or more of the above conditions, the UE can start early measurement. The UE sends a message 3 (for example, RRC Connection Request or RRC Connection Resume message) to the base station (1e-25) while performing frequency measurement and transmits a message 4 (for example, RRC Connection Setup or RRC Connection (1e-30) and transits to the RRC connection mode (1e-35). The UE may perform an early measurement when transmitting a message 5 (for example, RRC Connection Setup Complete or RRC Connection Resume Complete), and may transmit an indicator indicating that there is a frequency measurement result to be reported. In the message 5, a new indicator can be defined to indicate that there is a fast frequency measurement result, and an indicator rlf-InfoAvailable-r10 (RLF-RLC Connection Setup Complete or RRC Connection Resume Complete) Or an indicator indicating that there is information to report) or logMeasAvailable-r10 (indicator indicating that the measured information exists) (1e-40).

The base station performs fast frequency measurement to the terminal in the message 5 and confirms that there is a measurement result to report it, it can send a message to the terminal to report the measurement result to quickly report the frequency measurement result (1e- 45). For example, the base station can request frequency measurement result information from the UE using a UE information request in a DL-DCCH message. Upon receiving the message, the UE can quickly report an early measurement to the base station (fast measurement report, 1e-45). For example, when the UE receives the message, the UE can report the frequency measurement result using the measurementReport in the UL-DCCH message. In this case, the frequency measurement result indicates that the measurement results of the serving cell / frequency measurement (for example, NR-SS RSRP), the surrounding cell / frequency measurement result of the serving cell / frequency, Cell / frequency measurement results, and the like.

The condition for the terminal to stop early measurement may be as follows.

One. After sending message 5,

2. After receiving a message or command to report the frequency measurement result from the base station,

3. After constructing a message to report the frequency measurement result to the base station,

4. After sending a message to the base station to report the frequency measurement result,

5. If random access fails,

6. If the BS explicitly instructs the UE to suspend early measurement in the RRC message, for example, the RRC Connection Setup message or the RRC Connection Resume message instructs the UE to indicate an early measurement.

According to one or more of the above conditions, the UE can stop early measurement (1e-50).

In this case, the terminal measures the frequencies that it can measure, that is, the supported frequencies, from the fast frequency setting related information. In this case, the terminal may preferentially select a frequency to perform measurement according to a predetermined priority order have.

If the contention resolution fails in performing early measurement, the UE returns to the preamble transmission and can perform the random access procedure again. Thereafter, the UE may perform a fast frequency measurement indicator or frequency Even if there is no information related to the setting, it is possible to carry out an early measurement.

In addition, the UE can stop early measurement if the random access procedure fails.

Also, the UE can perform fast frequency measurement without instructing the UE to perform fast frequency measurement on the serving cell or the frequency.

 FIG. 1F shows a first embodiment in which the UE can perform early measurement in a next generation mobile communication system and can quickly report a frequency measurement (fast measurement report). FIG.

A terminal capable of performing early measurement and reporting a fast measurement report in the embodiment 1-2 may be one or more of the following cases.

One. All terminals supporting fast frequency measurement and fast frequency measurement report method

2. RRC deactivation mode A terminal (for example, as an indicator) designated to be able to perform fast frequency measurement and quick frequency measurement result report when the base station transits the terminal from the RRC connection mode to the RRC deactivation mode in the RRC message.

3. In a terminal in which MO (Mobile Oriented) data is generated, i.e., a terminal in which data to be transmitted in uplink exists

4. (E.g., mobile terminated) data is generated in the network (i.e., downlink data is generated), the paging message is received from the network, and the paging message is used to perform fast frequency measurement and quick frequency measurement report, As an indicator).

5. If the amount of data to be transmitted to the RRC idle mode terminal or the RRC deactivated mode terminal is greater than a predetermined threshold, the threshold value may be set as an RRC message in the base station or broadcast in the system information. The RRC message may be a message that transits from the RRC connection mode to the RRC idle mode or the RRC deactivation mode, or an RRC message that the UE can receive when establishing the previous connection.

6. RRC deactivation mode When a base station transitions from the RRC connection mode to the RRC deactivation mode in the RRC message, the base station can perform fast frequency measurement and report a fast frequency measurement result when it is in a specific paging area And the terminal in the paging area.

The terminal 1f-05 in the RRC idle mode or the RRC inactive mode in FIG. 1F may transmit the paging message to the terminal 1f-05 for a predetermined reason (for example, To update the RRC connection mode, etc.). The terminal can read the system information before attempting to connect (1f-10). The system information includes information on which frequencies or which frequency bands are to be measured (for example, a frequency list) when performing early measurement, a priority order for each frequency, When measuring the frequency, it is necessary to determine how to measure the frequency intensity by the filtering method (for example, L1 filtering, L2 filtering, L3 filtering method, or which coefficient is used and which calculation method is used) The frequency response measured according to an event or condition, the frequency at which the measurement is to be started according to an event or condition, the frequency at which the current serving cell (or currently camped frequency) is compared (Or the frequency at which the current cell is currently camped) Should I want to see the frequency, which cycles every want to report the frequency measurements can be set to give a frequency measurement configuration information (early measurement setup) and the like.

Upon confirming the frequency measurement setup information, the UE can transmit a preamble to the Node B as a first procedure of random access (1f-20). If the base station successfully receives the UE's promamble, it can send a random access response (RAR) to the UE (1f-25). At this time, the BS may transmit an indication indicating the fast frequency measurement to the UE in the random access response. Alternatively, the UE may start fast frequency measurement based on the frequency measurement setting information received from the system information even if there is no indicator in the random access response message.

The conditions for starting the frequency measurement when the UE performs early measurement may be as follows.

One. When entering RRC idle mode or RRC disable mode

2. When the frequency measurement related setting information is received from the system information

3. When the fast frequency measurement indicator is received and confirmed in the RAR message,

4. When a random access procedure transmits a preamble, that is, when a random access procedure is started

5. When the amount of data to be transmitted from the terminal exceeds a predetermined threshold value

According to one or more of the above conditions, the UE can start early measurement. The UE sends a message 3 (for example, an RRC Connection Request or an RRC Connection Resume message) to the base station while performing frequency measurement (1f-30), and transmits a message 4 (for example, RRC Connection Setup or RRC Connection (1f-35) and transits to the RRC connection mode (1f-40). The UE may perform an early measurement when transmitting a message 5 (for example, RRC Connection Setup Complete or RRC Connection Resume Complete), and may transmit an indicator indicating that there is a frequency measurement result to be reported. In the message 5, a new indicator can be defined to indicate that there is a fast frequency measurement result, and an indicator rlf-InfoAvailable-r10 (RLF-RLC Connection Setup Complete or RRC Connection Resume Complete) Or an indicator indicating that there is information to report) or logMeasAvailable-r10 (indicator indicating that the measured information exists) (1f-45).

The base station performs fast frequency measurement to the terminal in the message 5 and confirms that there is a measurement result to report it, it can send a message to the terminal to report the measurement result to quickly report the frequency measurement result (1f- 50). For example, the base station can request frequency measurement result information from the UE using a UE information request in a DL-DCCH message. Upon receiving the message, the UE can quickly report an early measurement to the base station (fast measurement report, 1f-60). For example, when the UE receives the message, the UE can report the frequency measurement result using the measurementReport in the UL-DCCH message. In this case, the frequency measurement result indicates that the measurement results of the serving cell / frequency measurement (for example, NR-SS RSRP), the surrounding cell / frequency measurement result of the serving cell / frequency, Cell / frequency measurement results, and the like.

The condition for the terminal to stop early measurement may be as follows.

One. After sending message 5,

2. After receiving a message or command to report the frequency measurement result from the base station,

3. After constructing a message to report the frequency measurement result to the base station,

4. After sending a message to the base station to report the frequency measurement result,

5. If random access fails,

6. If the BS explicitly instructs the UE to suspend early measurement in the RRC message, for example, the RRC Connection Setup message or the RRC Connection Resume message instructs the UE to indicate an early measurement.

According to one or more of the above conditions, the terminal can stop early measurement (1f-55).

In this case, the terminal measures the frequencies that it can measure, that is, the supported frequencies, from the fast frequency setting related information. In this case, the terminal may preferentially select a frequency to perform measurement according to a predetermined priority order have.

If the contention resolution fails in performing early measurement, the UE returns to the preamble transmission and can perform the random access procedure again. Thereafter, the UE may perform a fast frequency measurement indicator or frequency Even if there is no information related to the setting, it is possible to carry out an early measurement.

In addition, the UE can stop early measurement if the random access procedure fails.

Also, the UE can perform fast frequency measurement without instructing the UE to perform fast frequency measurement on the serving cell or the frequency.

FIG. 1G shows a first to third embodiments in which a UE can perform early measurement in a next generation mobile communication system and can quickly report a frequency measurement (fast measurement report). FIG.

In the first to third embodiments, a terminal capable of performing early measurement and reporting a fast measurement report may be one or more of the following cases.

One. All terminals supporting fast frequency measurement and fast frequency measurement report method

2. RRC deactivation mode A terminal (for example, as an indicator) designated to be able to perform fast frequency measurement and quick frequency measurement result report when the base station transits the terminal from the RRC connection mode to the RRC deactivation mode in the RRC message.

3. In a terminal in which MO (Mobile Oriented) data is generated, i.e., a terminal in which data to be transmitted in uplink exists

4. (E.g., mobile terminated) data is generated in the network (i.e., downlink data is generated), the paging message is received from the network, and the paging message is used to perform fast frequency measurement and quick frequency measurement report, As an indicator).

5. If the amount of data to be transmitted to the RRC idle mode terminal or the RRC deactivated mode terminal is greater than a predetermined threshold, the threshold value may be set as an RRC message in the base station or broadcast in the system information. The RRC message may be a message that transits from the RRC connection mode to the RRC idle mode or the RRC deactivation mode, or an RRC message that the UE can receive when establishing the previous connection.

6. RRC deactivation mode When a base station transitions from the RRC connection mode to the RRC deactivation mode in the RRC message, the base station can perform fast frequency measurement and report a fast frequency measurement result when it is in a specific paging area And the terminal in the paging area.

The terminal 1g-05 in the RRC connection mode in FIG. 1G may transmit an RRC idle mode or an RRC deactivation mode (RRC idle mode) by the base station for a predetermined reason (for example, inactive mode (1g-15). When switching to the mode of the terminal of the base station, an RRC message is sent (1g-10). For example, an RRC Connection Release message or an RRC Connection Suspend message. The RRC message includes information on which frequencies or certain frequency bands are to be measured (e.g., a frequency list) when performing early measurement, a priority order for each frequency, When measuring the frequency, it is necessary to determine how to measure the frequency intensity by the filtering method (for example, L1 filtering, L2 filtering, L3 filtering method, or which coefficient is used and which calculation method is used) The frequency response measured according to an event or condition, the frequency at which the measurement is to be started according to an event or condition, the frequency at which the current serving cell (or currently camped frequency) is compared , Or any criteria or condition when compared to the current serving cell (or current camp-on frequency) I want to see the frequency, which cycles every want to report the frequency measurements can be set to give a frequency measurement configuration information (early measurement setup) and the like.

Alternatively, the RRC message for switching the mode of the UE may not include the frequency measurement setup information, but may include only an indicator for early measurement. And the frequency measurement setup information may be reused from the system information or from the frequency measurement information used for cell reselection in the RRC idle mode.

Alternatively, the RRC message for switching the mode of the UE may not include the frequency measurement setup information, and may include an indicator for early measurement, and an indicator for indicating an early measurement when the UE transitions to the RRC deactivation mode. And to instruct the user to perform fast frequency measurement only in the paging area. And the frequency measurement setup information may be reused from the system information or from the frequency measurement information used for cell reselection in the RRC idle mode.

Alternatively, the RRC message for switching the mode of the UE may include the frequency measurement setting information as described above, an indicator for early measurement, and an indicator for indicating an early measurement when the UE transitions to the RRC deactivation mode. It is possible to set a paging area and direct the user to perform fast frequency measurement only in the paging area.

When the UE confirms the frequency measurement setup information and there is a reason to connect to the network for a predetermined reason, the UE can transmit the preamble to the Node B as a first procedure of random access (1g-20). If the base station successfully receives the UE's promamble, it can send a Random Access Response (RAR) to the UE (1g-25). At this time, the BS may transmit an indication indicating the fast frequency measurement to the UE in the random access response. Alternatively, the UE may start fast frequency measurement based on the frequency measurement setting information received from the system information even if there is no indicator in the random access response message.

The conditions for starting the frequency measurement when the UE performs early measurement may be as follows (1g-30).

One. When entering RRC idle mode or RRC disable mode

2. When the frequency measurement related setting information is received

3. When the fast frequency measurement indicator is received and confirmed in the RAR message,

4. When a random access procedure transmits a preamble, that is, when a random access procedure is started

5. When the amount of data to be transmitted from the terminal exceeds a predetermined threshold value

According to one or more of the above conditions, the UE can start early measurement. The UE sends a message 3 (for example, an RRC Connection Request or an RRC Connection Resume message) to the base station (1g-35) while performing frequency measurement and transmits a message 4 (for example, RRC Connection Setup or RRC Connection (1g-40) and transits to the RRC connection mode (1g-45). The UE may perform an early measurement when transmitting a message 5 (for example, RRC Connection Setup Complete or RRC Connection Resume Complete), and may transmit an indicator indicating that there is a frequency measurement result to be reported. In the message 5, a new indicator can be defined to indicate that there is a fast frequency measurement result, and an indicator rlf-InfoAvailable-r10 (RLF-RLC Connection Setup Complete or RRC Connection Resume Complete) Or an indicator indicating that there is information to report) or logMeasAvailable-r10 (an indicator indicating that the measured information is available) (1g-50).

The base station performs fast frequency measurement to the terminal in the message 5 and confirms that there is a measurement result to report it, it can send a message to the terminal to report the measurement result to quickly report the frequency measurement result (1g- 55). For example, the base station can request frequency measurement result information from the UE using a UE information request in a DL-DCCH message. Upon receiving the message, the UE can quickly report an early measurement to the base station (fast measurement report, 1g-65). For example, when the UE receives the message, the UE can report the frequency measurement result using the measurementReport in the UL-DCCH message. In this case, the frequency measurement result indicates that the measurement results of the serving cell / frequency measurement (for example, NR-SS RSRP), the surrounding cell / frequency measurement result of the serving cell / frequency, Cell / frequency measurement results, and the like.

The condition for the terminal to stop early measurement may be as follows.

One. After sending message 5,

2. After receiving a message or command to report the frequency measurement result from the base station,

3. After constructing a message to report the frequency measurement result to the base station,

4. After sending a message to the base station to report the frequency measurement result,

5. If random access fails,

6. If the BS explicitly instructs the UE to suspend early measurement in the RRC message, for example, the RRC Connection Setup message or the RRC Connection Resume message instructs the UE to indicate an early measurement.

Depending on one or more of the above conditions, the terminal may stop early measurement (1g-60).

In this case, the terminal measures the frequencies that it can measure, that is, the supported frequencies, from the fast frequency setting related information. In this case, the terminal may preferentially select a frequency to perform measurement according to a predetermined priority order have.

If the contention resolution fails in performing early measurement, the UE returns to the preamble transmission and can perform the random access procedure again. Thereafter, the UE may perform a fast frequency measurement indicator or frequency Even if there is no information related to the setting, it is possible to carry out an early measurement.

In addition, the UE can stop early measurement if the random access procedure fails.

Also, the UE can perform fast frequency measurement without instructing the UE to perform fast frequency measurement on the serving cell or the frequency.

In the next generation mobile communication system of the present invention proposed in FIG. 1E, FIG. 1F and FIG. 1G, a terminal can perform early measurement and can perform a fast measurement report The base station can quickly report the frequency measurement result through the first embodiment, the second embodiment, and the third embodiment, and the base station can quickly set up a frequency coherence technique or a dual access technique for the UE.

FIG. 1H is a diagram illustrating a terminal operation in which the UE performs an early measurement and a fast measurement report in a next generation mobile communication system according to the present invention.

The terminal 1h-01 transmits the frequency measurement setting information to the RRC message or the RRC message for switching the mode of the UE or the system information or the random access response message as described in the first embodiment, the second embodiment, It can be confirmed by re-use of frequency measurement setup information for cell reselection used in RRC idle mode (1h-05). If the UE confirms the frequency measurement setup information, the UE can start fast frequency measurement according to one or more of the following conditions (1h-10) as described above.

One. When entering RRC idle mode or RRC disable mode

2. When the frequency measurement related setting information is received

3. When the fast frequency measurement indicator is received and confirmed in the RAR message,

4. When a random access procedure transmits a preamble, that is, when a random access procedure is started

5. When the amount of data to be transmitted from the terminal exceeds a predetermined threshold value

The UE performs frequency measurement as described above and can stop fast frequency measurement according to one or more of the following conditions (1h-15) as described above.

One. After sending message 5,

2. After receiving a message or command to report the frequency measurement result from the base station,

3. After constructing a message to report the frequency measurement result to the base station,

4. After sending a message to the base station to report the frequency measurement result,

5. If random access fails,

6. If the BS explicitly instructs the UE to suspend early measurement in the RRC message, for example, the RRC Connection Setup message or the RRC Connection Resume message instructs the UE to indicate an early measurement.

  When the UE completes the fast frequency measurement result, it indicates to the base station that the frequency measurement result is present. If the base station requests the frequency measurement result information, the UE transmits the frequency measurement result information to the base station (1h-20).

FIG. 1I illustrates a structure of a terminal to which an embodiment of the present invention can be applied.

Referring to FIG. 1, the UE includes a Radio Frequency (RF) processor 1i-10, a baseband processor 1i-20, a storage 1i-30, and a controller 1i-40 .

The RF processor 1i-10 performs a function of transmitting and receiving a signal through a wireless channel such as band conversion and amplification of a signal. That is, the RF processor 1i-10 up-converts the baseband signal provided from the baseband processor 1i-20 to an RF band signal, and transmits the RF band signal through the antenna, To a baseband signal. For example, the RF processor 1i-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter . In the figure, only one antenna is shown, but the terminal may have a plurality of antennas. In addition, the RF processor 1i-10 may include a plurality of RF chains. Further, the RF processor 1i-10 may perform beamforming. For the beamforming, the RF processor 1i-10 can adjust the phase and size of signals transmitted and received through a plurality of antennas or antenna elements. In addition, the RF processor may perform MIMO and may receive multiple layers when performing a MIMO operation. The RF processor 1i-10 may perform reception beam sweeping by appropriately setting a plurality of antennas or antenna elements under the control of the controller, or adjust the direction and beam width of the reception beam such that the reception beam is coordinated with the transmission beam have.

The baseband processor 1i-20 performs a function of converting a baseband signal and a bit string according to a physical layer specification of the system. For example, at the time of data transmission, the baseband processing unit 1i-20 generates complex symbols by encoding and modulating transmission bit streams. Also, upon receiving the data, the baseband processing unit (1i-20) demodulates and decodes the baseband signal provided from the RF processing unit (1i-10) to recover the received bit stream. For example, in accordance with an orthogonal frequency division multiplexing (OFDM) scheme, the baseband processing unit 1i-20 generates complex symbols by encoding and modulating transmission bit streams and transmits the complex symbols to subcarriers And then constructs OFDM symbols by IFFT (Inverse Fast Fourier Transform) operation and CP (cyclic prefix) insertion. In addition, upon receiving data, the baseband processing unit 1i-20 divides the baseband signal provided from the RF processing unit 1i-10 into OFDM symbol units, and performs FFT (fast Fourier transform) operation on subcarriers Restores the mapped signals, and then restores the received bit stream through demodulation and decoding.

The baseband processing unit 1i-20 and the RF processing unit 1i-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 1i-20 and the RF processing unit 1i-10 may be referred to as a transmitting unit, a receiving unit, a transmitting / receiving unit, or a communication unit. Further, at least one of the baseband processor 1i-20 and the RF processor 1i-10 may include a plurality of communication modules to support a plurality of different radio access technologies. Also, at least one of the baseband processor 1i-20 and the RF processor 1i-10 may include different communication modules for processing signals of different frequency bands. For example, the different wireless access technologies may include an LTE network, an NR network, and the like. In addition, the different frequency bands may include a super high frequency (SHF) band (eg, 2.5 GHz, 5 GHz), and a millimeter wave (eg, 60 GHz) band.

The storage unit 1i-30 stores data such as a basic program, an application program, and setting information for operating the terminal. The storage unit 1i-30 provides the stored data at the request of the controller 1i-40.

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

1J illustrates a block diagram of a TRP in a wireless communication system to which an embodiment of the present invention may be applied.

As shown in the figure, the base station includes an RF processor 1j-10, a baseband processor 1j-20, a backhaul communication unit 1j-30, a storage unit 1j-40, .

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

The baseband processor 1j-20 performs a function of converting a baseband signal and a bit string according to a physical layer standard of the first radio access technology. For example, at the time of data transmission, the baseband processing unit (1 j-20) generates complex symbols by encoding and modulating transmission bit streams. Also, upon receiving data, the baseband processor 1j-20 demodulates and decodes the baseband signal provided from the RF processor 1j-10 to recover the received bitstream. For example, in accordance with the OFDM scheme, when data is transmitted, the baseband processor 1j-20 generates complex symbols by encoding and modulating transmission bit streams, maps the complex symbols to subcarriers, And constructs OFDM symbols through operation and CP insertion. In addition, upon 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 restores the signals mapped to the subcarriers through the FFT operation And then demodulates and decodes the received bit stream. The baseband processing unit 1j-20 and the RF processing unit 1j-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 1j-20 and the RF processing unit 1j-10 may be referred to as a transmitting unit, a receiving unit, a transmitting / receiving unit, a communication unit, or a wireless communication unit.

The communication unit 1j-30 provides an interface for performing communication with other nodes in the network.

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

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

≪ Embodiment 2 >

Hereinafter, the operation principle of the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

A term used for identifying a connection node used in the following description, a term referring to network entities, a term referring to messages, a term indicating an interface between network objects, a term indicating various identification information Etc. are illustrated for convenience of explanation. Therefore, the present invention is not limited to the following terms, and other terms referring to objects having equivalent technical meanings can be used.

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

2A is a diagram showing a structure of an LTE system to which the present invention can be applied.

2A, the radio access network of the LTE system includes an Evolved Node B (hereinafter, referred to as an ENB, a Node B or a base station) 2a-05, 2a-10, 2a-15 and 2a-20, MME 2a-25 (Mobility Management Entity) and S-GW (2a-30, Serving-Gateway). A user equipment (hereinafter referred to as a UE or a terminal) 2a-35 accesses an external network through the ENBs 2a-05 to 2a-20 and the S-GW 2a-30.

In FIG. 2A, the ENBs 2a-05 to 2a-20 correspond to the existing node B of the UMTS system. The ENB is connected to the UEs 2a-35 over a radio channel and plays a more complex role than the existing NodeB. In the LTE system, since all user traffic including a real-time service such as Voice over IP (VoIP) over the Internet protocol is serviced through a shared channel, status information such as buffer status, available transmission power status, And the ENB 2a-05 ~ 2a-20 takes charge of the scheduling. One ENB normally controls a plurality of cells. For example, in order to realize a transmission rate of 100 Mbps, an LTE system uses Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology, for example, at a bandwidth of 20 MHz. In addition, Adaptive Modulation and Coding (AMC) scheme is used to determine a modulation scheme and a channel coding rate in accordance with a channel state of a UE. The S-GW 2a-30 is a device for providing a data bearer and generates or removes a data bearer under the control of the MME 2a-25. The MME is a device that performs various control functions as well as a mobility management function for a terminal, and is connected to a plurality of base stations.

2B is a diagram illustrating a wireless protocol structure in an LTE system to which the present invention can be applied.

Referring to FIG. 2B, the wireless protocol of the LTE system includes PDCP (Packet Data Convergence Protocol 2b-05 and 2b-40), RLC (Radio Link Control 2b-10 and 2b-35) Control 2b-15, 2b-30. Packet Data Convergence Protocol (PDCP) (2b-05, 2b-40) performs operations such as IP header compression / decompression. The main functions of the 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 function (PDCP SDUs at handover and for split bearers in DC, PDCP PDUs at PDCP data-recovery procedure, for RLC AM)

- Ciphering and deciphering function

- Timer-based SDU discard in uplink.

Radio Link Control (RLC) (2b-10, 2b-35) reconfigures a PDCP PDU (Packet Data Unit) to an appropriate size and performs ARQ operations. The main functions of the RLC are summarized as follows.

- 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 (only for AM data transfer)

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

- RLC re-establishment function (RLC re-establishment)

MACs 2b-15 and 2b-30 are connected to a plurality of RLC layer devices arranged in one terminal, multiplex RLC PDUs into MAC PDUs, and demultiplex RLC PDUs from MAC PDUs. The main functions of the MAC are summarized as follows.

- Mapping between logical channels and transport channels.

- 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 (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification (MBMS service identification)

- Transport format selection function (Transport format selection)

- Padding function

The physical layers 2b-20 and 2b-25 channel-code and modulate the upper layer data, transmit them in a wireless channel by making them into OFDM symbols, or demodulate and decode OFDM symbols received through a wireless channel, .

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

2C, a radio access network of a next generation mobile communication system (hereinafter referred to as NR or 5G) includes a next generation base station (NR gNB or NR base station) 2c-10 and an NR CN 2c -05, New Radio Core Network). A user terminal (New Radio User Equipment) 2c-15 accesses the external network via the NR gNB 2c-10 and the NR CN 2c-05.

In FIG. 2C, the NR gNB (2c-10) corresponds to the eNB (Evolved Node B) of the existing LTE system. The NR gNB is connected to the NR UE 2c-15 by a radio channel and can provide a superior service than the existing Node B. In the next generation mobile communication system, since all user traffic is served through a shared channel, a device for collecting and scheduling state information such as buffer status, available transmission power state, and channel state of UEs is required. (2c-10). One NR gNB typically controls multiple cells. In order to realize high-speed data transmission in comparison with the current LTE, it can have an existing maximum bandwidth or more, and additionally, beam-forming technology can be applied by using Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology . In addition, Adaptive Modulation and Coding (AMC) scheme is used to determine a modulation scheme and a channel coding rate in accordance with a channel state of a UE. NR CN (2c-05) performs functions such as mobility support, bearer setup, and QoS setup. The NR CN is a device that performs various control functions as well as a mobility management function for a terminal, and is connected to a plurality of base stations. Also, the next generation mobile communication system can be interworked with the existing LTE system, and the NR CN is connected to the MME 2c-25 through a network interface. The MME is connected to the eNB (2c-30) which is an existing base station.

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

2d, the radio protocol of the next generation mobile communication system includes NR PDCPs 2d-05 and 2d-40, NR RLCs 2d-10 and 2d-35, and NR MACs 2d-15 and 2d- , 2d-30). The main functions of the 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

- Order reordering function (PDCP PDU reordering for reception)

- Duplicate detection of lower layer SDUs

- Retransmission of PDCP SDUs

- Ciphering and deciphering function

- Timer-based SDU discard in uplink.

In the above, the reordering function of the NR PDCP apparatus refers to a function of rearranging PDCP PDUs received in a lower layer in order based on a PDCP SN (sequence number), and transmitting data to an upper layer in the order of rearrangement And may include a function of directly transmitting PDCP PDUs without considering the order, and may include a function of recording lost PDCP PDUs by rearranging the order, and may include a status report for lost PDCP PDUs To the transmitting side, and may include a function of requesting retransmission of lost PDCP PDUs.

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

- 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 discard function (RLC SDU discard)

- RLC re-establishment function (RLC re-establishment)

The in-sequence delivery function of the NR RLC apparatus refers to a function of delivering RLC SDUs received from a lower layer to an upper layer in order, and an original RLC SDU is divided into a plurality of RLC SDUs And reassembling and delivering the received RLC PDUs when the RLC PDUs are received. The RLC PDUs may include a function of rearranging received RLC PDUs based on a RLC SN (sequence number) or a PDCP SN (sequence number) May include the capability to record lost RLC PDUs and may include the ability to send a status report for lost RLC PDUs to the sender and may include the ability to request retransmission of lost RLC PDUs And may include a function of transferring only the RLC SDUs up to the lost RLC SDU to the upper layer in order of the lost RLC SDU if there is a lost RLC SDU, If all the RLC SDUs received up to the present time have been expired, the RLC SDUs may be transmitted to the upper layer in order, To the upper layer in order. In addition, the RLC PDUs may be processed in the order of receiving the RLC PDUs (in the order of arrival of the sequence number and the sequence number), and may be transmitted to the PDCP device in an out-of-sequence delivery manner. It is possible to receive segments that are stored in the buffer or to be received at a later time, reconfigure the received segments into one complete RLC PDU, and transmit the segmented PDCP PDCP device to the PDCP device. The NR RLC layer may not include a concatenation function and may perform the function in the NR MAC layer or in place of the NR MAC layer multiplexing function.

The out-of-sequence delivery function of the NR RLC apparatus refers to a function of delivering RLC SDUs received from a lower layer directly to an upper layer regardless of order, SDUs, and reassembling and delivering the RLC PDUs when they are received. The RLC PDU includes a function of storing RLC SN or PDCP SN of the received RLC PDUs and recording the lost RLC PDUs by arranging the order .

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

- Mapping between logical channels and transport channels.

- Multiplexing / demultiplexing of MAC SDUs

- Scheduling information reporting function

- HARQ (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification (MBMS service identification)

- Transport format selection function (Transport format selection)

- Padding function

The NR PHY layers 2d-20 and 2d-25 channel-code and modulate the upper layer data, transmit them to the wireless channel by making them into OFDM symbols, or demodulate and decode the OFDM symbols received through the wireless channel, Can be performed.

FIG. 2E is a diagram for explaining a procedure for establishing a connection with a network by switching a terminal from the RRC idle mode to the RRC connected mode (RRC connected mode) in the present invention.

In FIG. 2E, if the UE transmitting and receiving data in the RRC connection mode is not transmitting or receiving data for a predetermined reason or for a predetermined time, the base station may send an RRCConnectionRelease message to the UE to switch the UE to the RRC idle mode (2e-01). If a terminal that is not currently connected (hereinafter, idle mode UE) generates data to be transmitted, it performs RRC connection establishment procedure with the base station. The MS establishes an uplink transmission synchronization with the BS through a random access procedure and transmits an RRCConnectionRequest message to the BS (2e-05). The message includes an identifier of the terminal and a reason for establishing a connection (establishmentCause). The base station transmits an RRCConnectionSetup message to establish the RRC connection (2e-10). Whether the PDCP layer device supports the sequential forwarding function (whether the non-sequential forwarding function is supported), whether the PDCP status report request function is used or not is determined for each logical channel or each bearer (whether RLC UM or RLC AM is connected) (PDCP Status report). For example, in logicalchannelconfig or pdcp-config, it is possible to indicate whether to support sequential forwarding function (non-sequential forwarding function is supported), whether to use PDCP status report request function (PDCP status report) Lt; RTI ID = 0.0 > RLC AM. ≪ / RTI > RRC connection configuration information and the like are stored in the message. The RRC connection is also called a Signaling Radio Bearer (SRB) and is used for transmitting / receiving RRC messages, which are control messages between the UE and the BS. The UE having established the RRC connection transmits the RRCConnetionSetupComplete message to the BS (2e-15). The message includes a control message called a SERVICE REQUEST for requesting the MME to set bearer for a predetermined service. The base station transmits the SERVICE REQUEST message stored in the RRCConnetionSetupComplete message to the MME (2e-20), and the MME determines whether to provide the service requested by the UE. As a result of the determination, if the UE determines to provide the requested service, the MME transmits an INITIAL CONTEXT SETUP REQUEST message to the BS (2e-25). The message includes QoS (Quality of Service) information to be applied when setting up a DRB (Data Radio Bearer) and security related information (e.g., Security Key, Security Algorithm) to be applied to the DRB. The base station exchanges SecurityModeCommand message (2e-30) and SecurityModeComplete message (2e-35) to establish security with the terminal. When the security setting is completed, the base station transmits an RRCConnectionReconfiguration message to the UE (2e-40). Whether the PDCP layer device supports the sequential forwarding function (whether the non-sequential forwarding function is supported), whether the PDCP status report request function is used or not is determined for each logical channel or each bearer (whether RLC UM or RLC AM is connected) (PDCP Status report). For example, in logicalchannelconfig or pdcp-config, it is possible to indicate whether to support sequential forwarding function (non-sequential forwarding function is supported), whether to use PDCP status report request function (PDCP status report) RLC AM, etc. In addition, the message includes setting information of a DRB to be processed by the user data, and the UE sets DRB by applying the information, and transmits an RRCConnectionReconfigurationComplete message to the base station (2e- 45). The base station that has completed the DRB setup sends the INITIAL CONTEXT SETUP COMPLETE message to the MME (2e-50). The MME receives the S1 BEARER SETUP message and the S1 BEARER SETUP RESPONSE message to set up the S- (2e-055, 2e-60). The S1 bearer is a data transmission connection established between the S-GW and the base station, and corresponds to the DRB on a one-to-one basis. When the above procedure is completed, the terminal transmits and receives data through the S-GW to the base station (2e-65, 2e-70). The general data transmission process consists of three stages: RRC connection setup, security setup, and DRB setup. Further, the base station may transmit the RRCConnectionReconfiguration message (2e-75) in order to renew, add, or change the setting to the UE for a predetermined reason. Whether the PDCP layer device supports the sequential forwarding function (whether the non-sequential forwarding function is supported), whether the PDCP status report request function is used or not is determined for each logical channel or each bearer (whether RLC UM or RLC AM is connected) (PDCP Status report). For example, in logicalchannelconfig or pdcp-config, it is possible to indicate whether to support sequential forwarding function (non-sequential forwarding function is supported), whether to use PDCP status report request function (PDCP status report) Lt; RTI ID = 0.0 > RLC AM. ≪ / RTI > The base station may request the BSR report using the RRC message.

FIG. 2F is a diagram illustrating a PUSH-based window operation that can be performed in the PDCP layer.

The PUSH-based window has a structure in which the window advances based on the lower edge of the window. The lower edge of the window is defined as the PDCP serial number (or COUNT value) most recently transferred to the upper layer, and is defined as a variable called Last_Submitted . In the above, the COUNT value is composed of 32 bits, and is composed of a combination of a PDCP serial number and an HFN (Hyper Frame Number). The HFN value is incremented by 1 each time the PDCP serial number is increased to the maximum value and reset to zero. If a packet is received outside the window as in 2f-05 of Figure 2f, it may be considered an old packet and discarded. However, when a packet is received in the window as in 2f-10, it is regarded as a normal packet, and it is confirmed whether or not the packet is duplicated. Then, the PDCP layer processes the data. The Last_submitted variable value is updated by the PDCP serial number (or COUNT value) of the packet transmitted to the upper layer, and the window advances accordingly. In the above, the size of the window is set to half the space that the PDCP serial number can have. For example, if the length of the PDCP serial number is 12 bits, the size of the window may be set to 2 ^ (12-1). A circle such as 2f-05 or 2f-10 in Figure 2f represents a window in which a smaller circle can be used to determine the HFN value. That is, circles having different colors or patterns have different HFNs.

FIG. 2G is a diagram illustrating a PULL-based window operation that can be performed in the PDCP layer.

The PULL-based window has a structure in which the window is advanced based on the upper edge of the window, and the upper edge of the window is defined as the highest PDCP serial number (or COUNT value) among the received packets and can be defined as a variable called RX_NEXT have. In the above, the COUNT value is composed of 32 bits, and is composed of a combination of a PDCP serial number and an HFN (Hyper Frame Number). The HFN value is incremented by 1 each time the PDCP serial number is increased to the maximum value and reset to zero. If a packet is received outside the window as in 2g-10 of Figure 2g, it is considered a new packet and accordingly the window upper edge is updated and the window can advance. However, when a packet is received in a window as in 2f-10, it is regarded as a normal packet and it is checked whether the packet is duplicated, and then the PDCP layer processes the data. In the above, the size of the window is set to half the space that the PDCP serial number can have. For example, if the length of the PDCP serial number is 12 bits, the size of the window may be set to 2 ^ (12-1). A circle such as 2g-05 or 2g-10 in Figure 2g represents a window in which a smaller circle can be used to determine the HFN value. That is, circles having different colors or patterns have different HFNs.

In the next generation mobile communication system, the UE can receive configuration information in the PDCP layer from the BS in steps 2e-10, 2e-40, and 2e-75 when it establishes connection with the network as shown in FIG.

Based on the setting information, the UE determines whether to support the sequential forwarding function of the PDCP layer connected to the RLC device having the RLC AM mode or the RLC UM mode (non-sequential forwarding function is supported), and whether to use the PDCP status report request function (PDCP status report) And the PDCP layer may have the following PDCP operation mode according to the setting.

One. Example 2-1: PDCP operation mode that supports sequential delivery and does not support PDCP status report request

2. Example 2-2: PDCP operation mode supporting sequential forwarding and supporting PDCP status report request

3. Embodiment 2-3 PDCP operation mode that supports non-sequential delivery and does not support PDCP status report request

4. Example 2-4 PDCP operation mode supporting non-sequential delivery and supporting PDCP status report request

The PDCP layer of the next generation mobile communication system may have a plurality of modes among the four modes.

In the embodiment 2-1 of the present invention, the PDCP layer supports the sequential delivery and supports the PDCP operation mode that does not support the PDCP status report request.

The receiving PDCP layer apparatus can use the PUSH window scheme as shown in FIG. 2F, or the pull window scheme as shown in FIG. 2G. Another way is to process the data using the PUSH window method, but the HFN decision can be determined by the PULL window method.

In order to support the sequential delivery of the PDCP layer device and support the PDCP status report request support in the 2-1 embodiment of the present invention, the following procedure may be employed.

In the embodiment 2-2 of the present invention, the PDCP layer device supports the non-sequential delivery and supports the PDCP operation mode that does not support the PDCP status report request.

The receiving PDCP layer apparatus can use the PUSH window scheme as shown in FIG. 2F, or the pull window scheme as shown in FIG. 2G. Another way is to process the data using the PUSH window method, but the HFN decision can be determined by the PULL window method.

In order to support the sequential delivery of the PDCP layer device and support the PDCP status report request in the embodiment 2-2 of the present invention, the following procedure may be employed.

In the 2-3th embodiment of the present invention, the PDCP layer device supports the non-sequential delivery and supports the PDCP operation mode that does not support the PDCP status report request.

The receiving PDCP layer apparatus can use the PUSH window scheme as shown in FIG. 2F, or the pull window scheme as shown in FIG. 2G. Another way is to process the data using the PUSH window method, but the HFN decision can be determined by the PULL window method.

In order to support the non-sequential delivery of the PDCP layer device and the operation of not supporting the PDCP status report request in the 2-3 < th > embodiment of the present invention, the following procedure may be employed.

In the second to fourth embodiments of the present invention, the PDCP layer device supports a PDCP operation mode that supports non-sequential delivery and does not support a PDCP status report request.

The receiving PDCP layer apparatus can use the PUSH window scheme as shown in FIG. 2F, or the pull window scheme as shown in FIG. 2G. Another way is to process the data using the PUSH window method, but the HFN decision can be determined by the PULL window method.

In order to support the non-sequential delivery of the PDCP layer device and support the PDCP status report request in the second to fourth embodiments of the present invention, the following procedure may be employed.

2H is a diagram illustrating a UE operation in which a UE receives PDCP layer setup information and determines a PDCP mode and operates according to the PDCP layer setup information.

In the next generation mobile communication system, when establishing a connection with the network as shown in FIG. 2H, the terminal 2h-01 determines from the base station which function to support in the PDCP layer in the procedure 2e-10, 2e-40, You can get it (2h-10).

The terminal confirms the setting information

If the first condition is satisfied, the first operation is performed (2h-15)

If the second condition is satisfied, the second operation is performed (2h-20)

If the third condition is satisfied, the third operation is performed (2h-25)

If the fourth condition is satisfied, the fourth operation is performed (2h-30).

The first condition indicates a case of including an indication of supporting a sequential function in each logical channel or each PDCP setting information and an indication of not supporting a PDCP status report request,

The second condition indicates an indication of supporting a sequential function in each logical channel or each PDCP setup information and an indication of supporting a PDCP status report request,

The third condition indicates a case of including an indication of supporting non-sequential function in each logical channel or each PDCP setup information and an indication of not supporting a PDCP status report request,

The fourth condition indicates a case of including an indicator of supporting non-sequential function in each logical channel or each PDCP setting information and an indicator of supporting a PDCP status report request.

The first operation refers to performing the PDCP mode operating according to the second embodiment of the present invention,

The second operation refers to performing the PDCP mode operating according to the second embodiment of the present invention,

The third operation refers to performing the PDCP mode operating according to the second to third embodiments of the present invention,

The fourth operation refers to performing the PDCP mode operating according to the second to fourth embodiments of the present invention.

FIG. 2I illustrates a structure of a terminal to which an embodiment of the present invention can be applied.

The terminal includes an RF (radio frequency) processing unit 2i-10, a baseband processing unit 2i-20, a storage unit 2i-30, and a control unit 2i-40 .

The RF processor 2i-10 performs a function of transmitting and receiving a signal through a wireless channel such as band conversion and amplification of a 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, and transmits the RF band signal through the antenna, To a baseband signal. For example, the RF processor 2i-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter . In the figure, only one antenna is shown, but the terminal may have a plurality of antennas. In addition, the RF processor 2i-10 may include a plurality of RF chains. Further, the RF processor 2i-10 may perform beamforming. For the beamforming, the RF processing unit 2i-10 may adjust the phase and size of signals transmitted and received through a plurality of antennas or antenna elements. In addition, the RF processor may perform MIMO and may receive multiple layers when performing a MIMO operation. The RF processing unit 2i-10 may perform reception beam sweeping by appropriately setting a plurality of antennas or antenna elements under the control of the controller, or adjust the direction and beam width of the reception beam such that the reception beam is coordinated with the transmission beam have.

The baseband processing unit 2i-20 performs a function of converting a baseband signal and a bit string according to a physical layer specification of the system. For example, at the time of data transmission, the baseband processing unit 2i-20 generates complex symbols by encoding and modulating transmission bit streams. In receiving the data, the baseband processing unit 2i-20 demodulates and decodes the baseband signal provided from the RF processing unit 2i-10 to recover the received bit stream. For example, when data is transmitted according to an orthogonal frequency division multiplexing (OFDM) scheme, the baseband processing unit 2i-20 generates complex symbols by encoding and modulating transmission bit streams, and outputs the complex symbols to subcarriers And then constructs OFDM symbols by IFFT (Inverse Fast Fourier Transform) operation and CP (cyclic prefix) 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 performs FFT (fast Fourier transform) operation on subcarriers Restores the mapped signals, and then restores the received bit stream through demodulation and decoding.

The baseband processing unit 2i-20 and the RF processing unit 2i-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 2i-20 and the RF processing unit 2i-10 may be referred to as a transmitting unit, a receiving unit, a transmitting / receiving unit, or a communication unit. In addition, at least one of the baseband processing unit 2i-20 and the RF processing unit 2i-10 may include a plurality of communication modules to support a plurality of different radio access technologies. Also, at least one of the baseband processing unit 2i-20 and the RF processing unit 2i-10 may include different communication modules for processing signals of different frequency bands. For example, the different wireless access technologies may include an LTE network, an NR network, and the like. In addition, the different frequency bands may include a super high frequency (SHF) band (eg, 2.5 GHz, 5 GHz), and a millimeter wave (eg, 60 GHz) band.

The storage unit 2i-30 stores data such as a basic program, an application program, and setting information for operating the terminal. The storage unit 2i-30 provides the stored data at the request of the controller 2i-40.

The controller 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. Also, the control unit 2i-40 writes data to the storage unit 2i-40 and reads the data. For this, the controller 2i-40 may include at least one processor. For example, the controller 2i-40 may include a communication processor (CP) for controlling communication and an application processor (AP) for controlling an upper layer such as an application program.

2J illustrates a block diagram of a TRP in a wireless communication system to which an embodiment of the present invention may be applied.

As shown in the figure, the base station includes an RF processor 2j-10, a baseband processor 2j-20, a backhaul communication unit 2j-30, a storage unit 2j-40, .

The RF processor 2j-10 performs a function of transmitting and receiving a signal through a wireless channel such as band conversion and amplification of a 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, and transmits the RF band signal through the antenna, To a baseband signal. For example, the RF processor 2j-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like. In the figure, only one antenna is shown, but the first access node may have a plurality of antennas. In addition, the RF processor 2j-10 may include a plurality of RF chains. Further, the RF processor 2j-10 may perform beamforming. For the beamforming, the RF processor 2j-10 may adjust the phase and size of signals transmitted and received through a plurality of antennas or antenna elements. The RF processor may perform downlink MIMO operation by transmitting one or more layers.

The baseband processing unit 2j-20 performs a function of converting a baseband signal and a bit string according to a physical layer standard of the first wireless access technology. For example, at the time of data transmission, the baseband processing unit 2j-20 generates complex symbols by encoding and modulating transmission bit streams. Also, upon receiving the data, the baseband processing unit 2j-20 demodulates and decodes the baseband signal provided from the RF processing unit 2j-10 to recover the received bit stream. For example, in accordance with the OFDM scheme, when data is transmitted, the baseband processing unit 2j-20 generates complex symbols by encoding and modulating transmission bit streams, maps the complex symbols to subcarriers, And constructs OFDM symbols through operation and CP insertion. Also, upon 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 the signals mapped to the subcarriers through the FFT operation And then demodulates and decodes the received bit stream. The baseband processing unit 2j-20 and the RF processing unit 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 transmitting unit, a receiving unit, a transmitting / receiving unit, a communication unit, or a wireless communication unit.

The communication unit 2j-30 provides an interface for performing communication with other nodes in the network.

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

The controller 2j-50 controls overall operations of the main base 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. Also, the control unit 2j-50 records and reads data in the storage unit 2j-40. To this end, the controller 2j-50 may include at least one processor.

2K illustrates a reception window operation in the PDCP layer of the next generation mobile communication system proposed in the present invention.

2K, a non-order delivery indicator (outOfOrderDelivery) is set in the PDCP device configuration information (pdcp-config) set in the RRC Connection Setup message or the RRC Connection Reconfiguration message in (2e-10, 2e-40, 2e- When order delivery is instructed, the order delivery operation is performed, and when not instructing non-order delivery, order delivery operation can be performed.

The out-of-order delivery indicator (outOfOrderDelivery) is included in an RRC Connection Setup message or an RRC Connection Reconfiguration message 2e-10, 2e-40, 2e-75 in FIG. 2E as an information element called RadioResourceConfigDedicated. have. Specifically, in the DRB-ToAddModList of the DRB-ToAddModList in the RadioResourceConfigDedicated, an outOfOrderDelivery indication may be defined in the pdcp-Config setting information to instruct non-sequential delivery.

The window state variables used in the receive packet processing operation of the receiving PDCP apparatus in FIG. 2K are as follows, and the window state variables retain the COUNT value.

- HFN: Indicates the HFN (Hyper Frame Number) part of the window state variable.

- SN: Represents the part of the window status variable (SN, Sequence Number).

- RCVD_SN: The PDCP serial number contained in the header of the received PDCP PDU

- RCVD_HFN: HFN value of the received PDCP PDU calculated by the receiving PDCP layer apparatus

- RCVD_COUNT: COUNT value of received PDCP PDU = [RCVD_HFN, RCVD_SN].

- RX_NEXT: Indicates the COUNT value of the next PDCP SDU expected to be received. The initial value is 0.

- RX_DELIV: indicates the COUNT value of the last PDCP SDU transmitted to the upper layer. The initial value is 2 ^ 32 -1.

- RX_REORD: indicates the next COUNT value of the COUNT value corresponding to the PDCP PDU that triggered the t-Reordering timer.

- t-Reordering: Use the timer value or interval set in the upper layer (RRC layer, RRC message, 1e-10, 1e-40.1e-75 in Fig. The timer is used to detect lost PDCP PDUs, and only one timer is driven at a time.

In this section, the following definitions are used:

- HFN (State Variable): the HFN part (i.e., the number of most significant bits equal to HFN length) of the State Variable.

- SN (State Variable): the SN part (i.e., the number of least significant bits equal to the PDCP SN length) of the State Variable.

- RCVD_SN: the PDCP SN of the received PDCP Data PDU, included in the PDU header.

- RCVD_HFN: the HFN of the received PDCP Data PDU, calculated by the receiving PDCP entity.

- RCVD_COUNT: the COUNT of the received PDCP Data PDU = [RCVD_HFN, RCVD_SN].

- RX_NEXT: This state variable indicates the COUNT value of the next PDCP SDU expected to be received. The initial value is 0.

- RX_DELIV: This state variable indicates the COUNT value of the last PDCP SDU delivered to the upper layers. The initial value is 2 ³² - 1.

- RX_REORD: This state variable indicates the COUNT value associated with the PDCP PDU which triggered the t-Reordering .

- t-Reordering: The duration of the timer is configured by the upper layers. This timer is used to detect loss of PDCP Data PDUs If t-Reordering is running, t-Reordering shall not be started additionally, ie only one t-Reordering per receiving PDCP entity is running at a given time.

A fifth embodiment of the reception operation of the PDCP layer proposed in the present invention is as follows.

Operation when PDCP PDU is received from the lower layer

(Actions when a PDCP Data PDU is received from lower layers)

When receiving a PDCP PDU from a lower layer, the receiving PDCP layer apparatus determines a COUNT value of the received PDCP PDU as follows.

- If the received RCVD_SN is RCVD_SN <= SN (RX_DELIV) - Window_Size

■ RCVD_HFN = HFN (RX_DELIV) + 1.

- Otherwise, if RCVD_SN is RCVD_SN> SN (RX_DELIV) + Window_Size

■ RCVD_HFN = HFN (RX_DELIV) - 1.

- If this is not the case

■ RCVD_HFN = HFN (RX_DELIV).

- RCVD_COUNT is determined as RCVD_COUNT = [RCVD_HFN, RCVD_SN].

At reception of a PDCP Data PDU from lower layers, the receiving PDCP entity will determine the COCP value of the received PDCP Data PDU, i.e. RCVD_COUNT, as follows:

- if RCVD_SN <= SN (RX_DELIV) - Window_Size:

  - RCVD_HFN = HFN (RX_DELIV) + 1;

- else if RCVD_SN > SN (RX_DELIV) + Window_Size:

  - RCVD_HFN = HFN (RX_DELIV) - 1;

- else:

- RCVD_HFN = HFN (RX_DELIV);

- RCVD_COUNT = [RCVD_HFN, RCVD_SN].

After determining the COUNT value of the received PDCP PDU, the receiving PDCP layer device updates the window status variables and processes the PDCP PDU as follows.

- If RCVD_COUNT <= RX_DELIV or a PDCP PDU with a value of RCVD_COUNT has been received previously

■ Performs decryption on the PDCP PDU using the RCVD_COUNT value, and performs integrity verification.

  ◆ If integrity verification fails

    ● Indicates failure of integrity verification of upper layer.

  ◆ And discards the PDCP PDU.

- In the other cases, the following operation is performed.

■ Performs decryption on the PDCP PDU using the RCVD_COUNT value, and performs integrity verification.

  ◆ If integrity verification fails

    ● Indicates failure of integrity verification of upper layer.

    Discard the PDCP PDU.

After determining the COCP value of the received PDCP Data PDU = RCVD_COUNT, the receiving PDCP entity shall:

- if RCVD_COUNT <= RX_DELIV; or

- if PDCP Data PDU with COUNT = RCVD_COUNT has been received before:

  - perform deciphering and integrity verification of the PDCP Data PDU using COUNT = RCVD_COUNT;

- if integrity verification fails:

- indicate integrity verification failure to upper layer;

- discard the PDCP Data PDU;

- else:

- perform deciphering and integrity verification of the PDCP Data PDU using COUNT = RCVD_COUNT;

- if integrity verification fails:

- indicate integrity verification failure to upper layer;

- discard the PDCP Data PDU;

If the received PDCP PDU is not discarded, the receiving PDCP layer apparatus operates as follows.

- And stores the processed PDCP SDU in the reception buffer.

- If RCVD_COUNT> = RX_NEXT

■ Update RX_NEXT to RCVD_COUNT + 1.

- If RCVD_COUNT is RX_DELIV + 1 and nonsequential delivery is not set

■ After decompressing the header, it transfers to the upper layer in order of COUNT value.

  ◆ COUNT = RX_DELIV + 1, and delivers all the consecutive PDCP SDUs to the upper layer.

■ The RX_DELIV value is updated to the COUNT value of the last PDCP SDU transmitted to the upper layer.

- If RCVD_COUNT is set to RX_DELIV + 1 and non-ordered delivery is set and the PDCP SDU corresponding to the RCVD_COUNT value has not been delivered to the upper layer

■ And transmits the resultant PDCP SDU to the upper layer after performing header decompression.

■ The RX_DELIV value is updated to the COUNT value of the last PDCP SDU transmitted in order to the upper layer.

- If the non-sequential delivery has been established and the PDCP SDU corresponding to the RCVD_COUNT value has not been delivered to the upper layer

■ And transmits the resultant PDCP SDU to the upper layer after performing header decompression.

- If the t-reordering timer is running and no PDU SDU with COUNT value of RX_REORD - 1 is delivered to the upper layer

■ Stop and reset the t-reordering timer.

- If at least one PDCP SDU is left in the buffer if the t-reordering timer is not running, no non-ordered delivery is set (even if stopped in this condition)

■ Update the RX_REORD value to RX_NEXT.

■ Start the t-reordering timer.

- If the t-reordering timer is running and non-ordered delivery is set

■ If RX_REORD = RX_DELIV + 1 or RX_REORD <= RX_DELIV,

  ◆ Stop and reset the t-reordering timer.

- If the t-reordering timer is not running and non-ordered delivery is set

■ If RX_NEXT> RX_DELIV + 1

  ◆ Update RX_REORD to RX_NEXT.

  ◆ Start the t-reordering timer.

If the received PDCP Data PDU with COUNT value = RCVD_COUNT is not discarded above, the receiving PDCP entity shall:

- store the resulting PDCP SDU in the reception buffer;

- if RCVD_COUNT> = RX_NEXT:

- update RX_NEXT to RCVD_COUNT + 1;

- if RCVD_COUNT = RX_DELIV + 1 and if outOfOrderDelivery is not configured:

- deliver to upper layers in ascending order of associated COUNT value after performing header decompression;

- all stored PDCP SDU (s) with consecutively associated COUNT value (s) starting from COUNT = RX_DELIV + 1;

- update RX_DELIV to the COUNT value of the last PDCP SDU delivered to upper layers;

- if RCVD_COUNT = RX_DELIV + 1 and if outOfOrderDelivery is configured and the PDCP SDU with RCVD_COUNT has not been delivered to upper layers:

- deliver the resulting PDCP SDU to upper layers after performing header decompression;

- update RX_DELIV to the COUNT value of the last in-sequence delivered PDCP SDU to upper layers;

- if outOfOrderDelivery is configured and the PDCP SDU with RCVD_COUNT has not been delivered to upper layers:

- deliver the resulting PDCP SDU to upper layers after performing header decompression;

- if t-Reordering is running and outOfOrderDelivery is not configured, and if the PDCP SDU with COUNT = RX_REORD - 1 has been delivered to upper layers:

- stop and reset t-Reordering ;

- if t-Reordering is not running and outOfOrderDelivery is not configured (includes the case when t-Reordering is stopped due to actions above), and if there is at least one stored PDCP SDU:

- update RX_REORD to RX_NEXT;

- start t-Reordering .

if -Reordering is running and outOfOrderDelivery is configured,

- if RX_REORD = RX_DELIV + 1; or

- if RX_REORD <= RX_DELIV (or RX_REORD falls outside of the receiving window and RX_REORD is not equal to RX_DELIV + Window_Size)

- stop and reset t-Reordering ;

- if t-Reordering is not running and outOfOrderDelivery is configured (includes the case when t-Reordering is stopped due to actions above)

- if RX_NEXT> RX_DELIV + 1 (or RX_NEXT -1> RX_DELIV):

- update RX_REORD to RX_NEXT;

- start t-Reordering .

The receiving PDCP layer device operation when the t-reordering timer expires.

(Actions when a t-Reordering expires)

If non-ordered delivery is not set, the receiving PDCP layer device operates as follows when the t-reordering timer expires.

- After decompressing the header, the COUNT value is transmitted to the upper layer in order.

■ All PDCP SDUs having COUNT values smaller than the RX_REORD value are transmitted.

■ All PDCP SDUs having consecutive COUNT values starting from the RX_REORC value are transmitted.

- The RX_DELIV value is updated to the COUNT value of the last PDCP SDU transmitted to the upper layer.

- If at least one PDCP SDU is stored in the buffer

■ Update the RX_REORD value to the RX_NEXT value.

■ Start the t-reordering timer.

If non-ordered delivery is set, the receiving PDCP layer device operates as follows when the t-reordering timer expires.

- RX_DELIV is updated to the last COUNT value transmitted in order to the upper layer, which is equal to or greater than the RX_REORD value.

- If RX_NEXT> RX_DELIV + 1

■ Update the RX_REORD value to the RX_NEXT value.

■ Start the t-reordering timer.

If outOfOrderDelivery is not configured, when t-Reordering expires, the receiving PDCP entity shall:

- deliver to upper layers in ascending order of associated COUNT value after performing header decompression:

- all stored PDCP SDU (s) with associated COUNT value (s) <RX_REORD;

- all stored PDCP SDU (s) with consecutively associated COUNT value (s) starting from RX_REORD;

- update RX_DELIV to the COUNT value of the last PDCP SDU delivered to upper layers;

- if there is at least one stored PDCP SDU:

- update RX_REORD to RX_NEXT;

- start t-Reordering .

If outOfOrderDelivery is configured, when t-Reordering expires, the receiving PDCP entity shall:

- update RX_DELIV to the COUNT value> = RX_REORD of the last in-sequence delivered PDCP SDU to upper layers;

- If RX_NEXT> RX_DELIV + 1 (or RX_NEXT -1> RX_DELIV):

- update RX_REORD to RX_NEXT

- start t-Reordering

A sixth embodiment of the reception operation of the PDCP layer proposed in the present invention is as follows.

Operation when PDCP PDU is received from the lower layer

(Actions when a PDCP Data PDU is received from lower layers)

When receiving a PDCP PDU from a lower layer, the receiving PDCP layer apparatus determines a COUNT value of the received PDCP PDU as follows.

- If the received RCVD_SN is RCVD_SN <= SN (RX_DELIV) - Window_Size

■ RCVD_HFN = HFN (RX_DELIV) + 1.

- Otherwise, if RCVD_SN is RCVD_SN> SN (RX_DELIV) + Window_Size

■ RCVD_HFN = HFN (RX_DELIV) - 1.

- If this is not the case

■ RCVD_HFN = HFN (RX_DELIV).

- RCVD_COUNT is determined as RCVD_COUNT = [RCVD_HFN, RCVD_SN].

At reception of a PDCP Data PDU from lower layers, the receiving PDCP entity will determine the COCP value of the received PDCP Data PDU, i.e. RCVD_COUNT, as follows:

- if RCVD_SN <= SN (RX_DELIV) - Window_Size:

- RCVD_HFN = HFN (RX_DELIV) + 1;

- else if RCVD_SN > SN (RX_DELIV) + Window_Size:

- RCVD_HFN = HFN (RX_DELIV) - 1;

- else:

- RCVD_HFN = HFN (RX_DELIV);

- RCVD_COUNT = [RCVD_HFN, RCVD_SN].

After determining the COUNT value of the received PDCP PDU, the receiving PDCP layer device updates the window status variables and processes the PDCP PDU as follows.

- If RCVD_COUNT <= RX_DELIV or a PDCP PDU with a value of RCVD_COUNT has been received previously

■ Performs decryption on the PDCP PDU using the RCVD_COUNT value, and performs integrity verification.

  ◆ If integrity verification fails

    ● Indicates failure of integrity verification of upper layer.

  ◆ And discards the PDCP PDU.

- In the other cases, the following operation is performed.

■ Performs decryption on the PDCP PDU using the RCVD_COUNT value, and performs integrity verification.

  ◆ If integrity verification fails

    ● Indicates failure of integrity verification of upper layer.

    Discard the PDCP PDU.

After determining the COCP value of the received PDCP Data PDU = RCVD_COUNT, the receiving PDCP entity shall:

- if RCVD_COUNT <= RX_DELIV; or

- if PDCP Data PDU with COUNT = RCVD_COUNT has been received before:

- perform deciphering and integrity verification of the PDCP Data PDU using COUNT = RCVD_COUNT;

- if integrity verification fails:

- indicate integrity verification failure to upper layer;

- discard the PDCP Data PDU;

- else:

- perform deciphering and integrity verification of the PDCP Data PDU using COUNT = RCVD_COUNT;

- if integrity verification fails:

- indicate integrity verification failure to upper layer;

- discard the PDCP Data PDU;

If the received PDCP PDU is not discarded, the receiving PDCP layer apparatus operates as follows.

- And stores the processed PDCP SDU in the reception buffer.

- If RCVD_COUNT> = RX_NEXT

■ Update RX_NEXT to RCVD_COUNT + 1.

- If RCVD_COUNT is RX_DELIV + 1 and nonsequential delivery is not set

■ After decompressing the header, it transfers to the upper layer in order of COUNT value.

  ◆ COUNT = RX_DELIV + 1, and delivers all the consecutive PDCP SDUs to the upper layer.

■ The RX_DELIV value is updated to the COUNT value of the last PDCP SDU transmitted to the upper layer.

- If RCVD_COUNT is set to RX_DELIV + 1 and non-ordered delivery is set and the PDCP SDU corresponding to the RCVD_COUNT value has not been delivered to the upper layer

■ And transmits the resultant PDCP SDU to the upper layer after performing header decompression.

■ The RX_DELIV value is updated to the COUNT value of the last PDCP SDU transmitted in order to the upper layer.

- If the non-sequential delivery has been established and the PDCP SDU corresponding to the RCVD_COUNT value has not been delivered to the upper layer

■ And transmits the resultant PDCP SDU to the upper layer after performing header decompression.

- If the t-reordering timer is running

■ If RX_REORD = RX_DELIV + 1 or RX_REORD <= RX_DELIV,

  ◆ Stop and reset the t-reordering timer.

- If the t-reordering timer is not running

■ If RX_NEXT> RX_DELIV + 1

  ◆ Update RX_REORD to RX_NEXT.

  ◆ Start the t-reordering timer.

If the received PDCP Data PDU with COUNT value = RCVD_COUNT is not discarded above, the receiving PDCP entity shall:

- store the resulting PDCP SDU in the reception buffer;

- if RCVD_COUNT> = RX_NEXT:

- update RX_NEXT to RCVD_COUNT + 1;

- if RCVD_COUNT = RX_DELIV + 1 and if outOfOrderDelivery is not configured:

- deliver to upper layers in ascending order of associated COUNT value after performing header decompression;

- all stored PDCP SDU (s) with consecutively associated COUNT value (s) starting from COUNT = RX_DELIV + 1;

- update RX_DELIV to the COUNT value of the last PDCP SDU delivered to upper layers;

- if RCVD_COUNT = RX_DELIV + 1 and if outOfOrderDelivery is configured and the PDCP SDU with RCVD_COUNT has not been delivered to upper layers:

- deliver the resulting PDCP SDU to upper layers after performing header decompression;

- update RX_DELIV to the COUNT value of the last in-sequence delivered PDCP SDU to upper layers;

- if outOfOrderDelivery is configured and the PDCP SDU with RCVD_COUNT has not been delivered to upper layers:

- deliver the resulting PDCP SDU to upper layers after performing header decompression;

- if t-Reordering is running,

- if RX_REORD = RX_DELIV + 1; or

- if RX_REORD <= RX_DELIV (or RX_REORD falls outside of the receiving window and RX_REORD is not equal to RX_DELIV + Window_Size + 1)

- stop and reset t-Reordering ;

- if t-Reordering is not running (includes the case when t-Reordering is stopped due to actions above)

- if RX_NEXT> RX_DELIV + 1 (or RX_NEXT -1> RX_DELIV):

- update RX_REORD to RX_NEXT;

- start t-Reordering .

The receiving PDCP layer device operation when the t-reordering timer expires.

(Actions when a t-Reordering expires)

If non-ordered delivery is not set, the receiving PDCP layer device operates as follows when the t-reordering timer expires.

- After decompressing the header, the COUNT value is transmitted to the upper layer in order.

■ All PDCP SDUs having COUNT values smaller than the RX_REORD value are transmitted.

■ All PDCP SDUs having consecutive COUNT values starting from the RX_REORC value are transmitted.

- The RX_DELIV value is updated to the COUNT value of the last PDCP SDU transmitted to the upper layer.

- If at least one PDCP SDU is stored in the buffer

■ Update the RX_REORD value to the RX_NEXT value.

■ Start the t-reordering timer.

If non-ordered delivery is set, the receiving PDCP layer device operates as follows when the t-reordering timer expires.

- RX_DELIV is updated to the last COUNT value transmitted in order to the upper layer, which is equal to or greater than the RX_REORD value.

- If RX_NEXT> RX_DELIV + 1

■ Update the RX_REORD value to the RX_NEXT value.

■ Start the t-reordering timer.

If outOfOrderDelivery is not configured, when t-Reordering expires, the receiving PDCP entity shall:

- deliver to upper layers in ascending order of associated COUNT value after performing header decompression:

- all stored PDCP SDU (s) with associated COUNT value (s) <RX_REORD;

- all stored PDCP SDU (s) with consecutively associated COUNT value (s) starting from RX_REORD;

- update RX_DELIV to the COUNT value of the last PDCP SDU delivered to upper layers;

- if there is at least one stored PDCP SDU:

- update RX_REORD to RX_NEXT;

- start t-Reordering .

If outOfOrderDelivery is configured, when t-Reordering expires, the receiving PDCP entity shall:

- update RX_DELIV to the COUNT value> = RX_REORD of the last in-sequence delivered PDCP SDU to upper layers;

- If RX_NEXT> RX_DELIV + 1 (or RX_NEXT -1> RX_DELIV):

- update RX_REORD to RX_NEXT

start t-Reordering

In the embodiments of the present invention

- update RX_DELIV to the COUNT value of the last in-sequence delivered PDCP SDU to upper layers;

Can be replaced with another phrase having the same meaning as follows.

- update RX_DELIV to x-1, where x is the COUNT value of the first PDCP SDU.

That is, the two phrases have the same meaning.

Also, in the embodiments of the present invention, when the PDCP layer device is set to perform non-sequential delivery, that is, when out-of-sequence delivery is set as an RRC message, a header compression algorithm (for example, RoHC) Since the compression algorithm can normally successfully perform the decompression algorithm only for the packets that are delivered in sequence, the receiving PDCP layer device can successfully perform the decompression algorithm), and thus the header decompression process of the receiving PDCP layer device can be omitted have.

&Lt; Third Embodiment >

Hereinafter, the operation principle of the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

A term used for identifying a connection node used in the following description, a term referring to network entities, a term referring to messages, a term indicating an interface between network objects, a term indicating various identification information Etc. are illustrated for convenience of explanation. Therefore, the present invention is not limited to the following terms, and other terms referring to objects having equivalent technical meanings can be used.

For convenience of explanation, the present invention uses terms and names defined in the 3GPP LTE (Long Term Evolution) standard, which is the most recent standard among existing communication standards. However, the present invention is not limited by the above-mentioned terms and names, and can be equally applied to systems conforming to other standards. In particular, the present invention is applicable to 3GPP NR (New Radio: 5th generation mobile communication standard).

FIG. 3A is a diagram showing a structure of a LTE system as a reference for explaining the present invention.

3A, the wireless communication system includes a plurality of base stations 3a-05, 3a-10, 3a-15, 3a-20, a Mobility Management Entity (MME) And a Serving-Gateway (GW) 3a-30. A user equipment (hereinafter referred to as a UE or a terminal) 3a-35 is connected to the outside through the base stations 3a-05, 3a-10, 3a-15, 3a-20 and S- Connect to the network.

The base stations 3a-05, 3a-10, 3a-15, and 3a-20 are access nodes of a cellular network and provide wireless access to terminals connected to the network. That is, in order to service the traffic of users, the base stations 3a-05, 3a-10, 3a-15, 3a-20 collect status information such as buffer status, available transmission power status, And supports connection between the UEs and a core network (CN) by performing scheduling. The MME 3a-25 is a device for performing various control functions as well as a mobility management function for a terminal, and is connected to a plurality of base stations, and the S-GW 3a-30 provides a data bearer. The MME 3a-25 and the S-GW 3a-30 may further perform authentication and bearer management for the MSs connected to the network, (3a-10) (3a-15) (3a-20) or packets to be transmitted to the base station 3a-05 (3a-10) 3a-15 (3a-20).

FIG. 3B is a diagram illustrating a wireless protocol structure of an LTE system for the purpose of explanation of the present invention. The NR to be defined in the future may be partially different from the radio protocol structure in this figure, but will be described for convenience of explanation of the present invention.

3B, the wireless protocol of the LTE system includes Packet Data Convergence Protocol (PDCP) (3b-05) 3b-40 and RLC (Radio Link Control) 3b-10 ), And a MAC (Medium Access Control) 3b-15 (3b-30). The Packet Data Convergence Protocol (PDCP) 3b-05 3b-40 is responsible for operations such as IP header compression / decompression and performs Radio Link Control (RLC) 3b-10 -35) reconfigures the PDCP PDU (Packet Data Unit) to an appropriate size. The MAC (3b-15) 3b-30 is connected to a plurality of RLC layer devices arranged in one terminal, multiplexes RLC PDUs into MAC PDUs, and demultiplexes RLC PDUs from MAC PDUs. The physical layer 3b-20 (3b-25) channel-codes and modulates the upper layer data, converts the OFDM symbol into an OFDM symbol and transmits the OFDM symbol on a wireless channel, or demodulates and decodes an OFDM symbol received on a wireless channel, . Also, in the physical layer, HARQ (Hybrid ARQ) is used for additional error correction. In the receiving end, transmission of the packet transmitted from the transmitting end is carried out with 1 bit. This is called HARQ ACK / NACK information. The downlink HARQ ACK / NACK information for uplink transmission is transmitted through a PHICH (Physical Hybrid-ARQ Indicator Channel) physical channel, and the uplink HARQ ACK / NACK information for downlink transmission includes a Physical Uplink Control Channel (PUCCH) (Physical Uplink Shared Channel) physical channel.

Meanwhile, the PHY layer may be composed of one or a plurality of frequency / carriers, and a technique of simultaneously setting and using a plurality of frequencies in one base station is referred to as a carrier aggre- gation (CA). The CA technology is a technique in which only one carrier is used for communication between a UE (User Equipment, UE) and a base station (E-UTRAN NodeB, eNB), and the subcarrier is further used by using one or more sub- It is possible to dramatically increase the amount of transmission. In LTE, a cell in a base station using a main carrier is referred to as PCell (Primary Cell), and a secondary carrier is referred to as SCell (Secondary Cell). A technology in which the CA function is extended to two base stations is referred to as dual connectivity (hereinafter referred to as DC). In the DC technique, a UE concurrently connects a Master E-UTRAN NodeB (MeNB) and a Secondary E-UTRAN NodeB (SeNB) (MCG), and cells belonging to the auxiliary base station are referred to as a secondary cell group (SCG). The representative cell of the main cell group is referred to as a primary cell (hereinafter referred to as PCell), and the representative cell of the auxiliary cell group is referred to as a primary secondary cell (hereinafter referred to as PSCell) do. When using the above-mentioned NR, the MCG can use LTE technology and the SCG can be used as NR so that the UE can simultaneously use LTE and NR.

Although not shown in the figure, RRC (Radio Resource Control) layers exist in the upper part of the PDCP layer of the UE and the base station, respectively. The RRC layer transmits connection and measurement related control messages for radio resource control You can send and receive. For example, the RRC layer can instruct the UE to perform measurement using the RRC layer message, and the UE can report the measurement result to the RAS using the RRC layer message.

3C is a diagram for explaining the concept of the Dual Connectivity.

In the illustrated example, the terminal 3c-05 uses the macro base station 3c-00 using the LTE technology and the NR technology. And the small cell base station 3c-10 are simultaneously connected to transmit and receive data. This is referred to as EN-DC (E-UTRAN-NR Dual Connectivity). The macro base station is referred to as MeNB (Master E-UTRAN NodeB) and the small cell base station is referred to as SgNB (Secondary 5G NodeB). There may be a plurality of small cells in the service area of the MeNB, and the MeNB is connected to the SgNBs via the wired backhaul network 3c-15. A set of serving cells received from the MeNB is referred to as a master cell group (MCG) 3c-20. In a MCG, one serving cell must have all the functions that the existing cell has performed, such as connection establishment, connection re- PCell (primary cell) (3c-25). In the PCell, the uplink control channel has a PUCCH. The serving cell other than the PCell is referred to as SCell (Secondary Cell) (3c-30). FIG. 3C shows a scenario in which MeNB provides one SCell and SgNB provides three SCells. The set of serving cells provided by the SgNB is called a secondary cell group (SCG) 3c-40. MeNB sends a command to the SgNB to add, change and remove the serving cells provided by the SgNB when the UE transmits and receives data from two base stations. In order to issue such a command, the MeNB can configure the UE to measure the serving cell and neighboring cells. The terminal shall report the measurement result to MeNB according to the setting information. In order for the SgNB to efficiently transmit and receive data to the UE, a serving cell that plays a role similar to that of the MCG is required. In the present invention, this is referred to as a PSCell (Primary SCell). The PSCell is defined as one of the serving cells of the SCG and has an uplink control channel PUCCH. The PUCCH is used by the UE to transmit HARQ ACK / NACK information, CSI (Channel Status Information) information, and SR (Scheduling Request) to the BS.

FIG. 3D is an exemplary diagram of a message flow between a terminal and a base station when a method of determining and processing a connection failure when a terminal performs simultaneous connection with a plurality of base stations of the same or different RATs.

Although the terminal connected to the LTE and the NR base station is illustrated as an example for convenience of explanation in the present exemplary drawing, the present invention can also be applied to a plurality of connections between homogeneous base stations (for example, an NR base station and an NR base station).

In the drawing, the terminal 3d-01 in the sleep mode (RRC_IDLE) performs connection to the LTE cell for the reason such as generation of data to be transmitted (3d-11). In the sleep mode, data can not be transmitted because the mobile station is not connected to the network for power saving or the like. In order to transmit data, a transition to a connection mode (RRC_CONNECTED) is required. If the UE succeeds in the connection procedure to the LTE cell 3d-03, the UE changes its state to the RRC_CONNECTED state, and the UE in the connected mode receives a Signaling Radio Bearer (SRB) And then data can be transmitted / received to and from the LTE cell through security activation and bearer (data radio bearer, DRB) setting for data. The bearer for the control message is divided into SRB1 and SRB2 according to the control message type.

If the base station determines to add the NR cell to the terminal by SCG, the base station transmits the SCG setup information to the terminal in order to set the DC function (3d-13). The SCG setting information may include addition and cancellation information for SCells to be added to the SCG. In addition, information for further setting the SRB 3 so that the control message generated by the SCG can be transmitted through the SCG base station may be included. In addition, information on a bearer to be transmitted through the SCG may be included. The configuration information can be transmitted using the RRConnectionReconfiguration message of the RRC layer. Thereafter, the UE transmits a message confirming that it has received the setup information, which can be transmitted using the RRCConnectionReconfigurationComplete message (3d-15). Accordingly, the UE can simultaneously transmit and receive data using the LTE cell 3d-03, which is an MCG, and the NR cell 3d-05, which is an SCG. When SRB3 is set, the control message can be transmitted / received through the SRB3 (3d- 17) (3d-19). In addition, a packet transmitted to the SRB1 / 2 may be copied and transmitted by MCG and SCG for reasons of stability. Likewise, a packet transmitted to the SRB 3 may be copied and transmitted by SCG and MCG. This is called a split bearer. The bearer that transmits data from the MCG CN connected to the MCG to the MCG and the SCG is called the MCG split bearer, and the bearer that transmits the data from the SCG CN connected to the SCG to the SCG and the MCG is called the SCG split bearer. And may be applied to both uplink and downlink.

When the MS transmits / receives data to / from the SRB or the DRB, the MS can perform an integrity check on each packet. The integrity check is to determine whether a packet is corrupted (by a malicious user, etc.). For this purpose, MAC-I (Message Authentication Code for Integrity) may be included for each packet. The receiving terminal can decrypt the MAC-I generated according to a specific encryption key and a predetermined rule, and confirm whether the corresponding information is correct and whether the packet is damaged or not. SRB These packets always include MAC-I, and DRB packets can be included in DRB according to the setting of the base station.

Accordingly, the UE performs an integrity check on the SRB or the set DRB. If an error occurs during SRB or DRB integrity check (3d-21), the UE determines which bearer has failed. If the bearer is an SRB (i.e., SRB1 or SRB2) of the MCG or an MCG DRB (including bearer and MCG split bearer only to be transmitted to MCG), the terminal may perform RRC connection reset (RRC Connection Reestablishment procedure. That is, the UE selects one cell in the neighbor cell through the cell selection procedure, and then attempts to recover the connection by transmitting an RRConnectionReestablishment message of the RRC layer to the corresponding cell. If the bearer is the SRB of the SCG (i.e., SRB3) or the SCG DRB (including the bearer and the SCG split bearer only transmitted to the SCG), the terminal aborts both the transmission of the SCG DRB and the transmission of the split DRB to the SCG, The transmission of the SRB3 and the transmission of the split SRB1 / 2 to the SCG are also interrupted (3d-23). In addition, the error is reported to the MCG base station (3d-25). The SCGFailureInformation message of the RRC layer at the time of reporting may be used, and information indicating that the cause of the failure is an SRB3 (or SCG DRB) integrity check error may be included in the message. In addition, the PDCP status report of the PDCP layer is generated for the SRB or the DRB that satisfies the following conditions, and the MCG base station is reported to the MCG base station (step 3d-27).

- MCG split DRB or SCG split DRB (or split SRB1 / 2/3)

- DRBs with statusReportRequired set in the DRB

This informs the MCG base station which downlink packet was correctly received and notifies the SCG that the lost data is recoverable.

Thereafter, when the base station determines to add the NR cell to the terminal in the same manner as described above, the base station transmits the SCG configuration information to the terminal in order to set the DC function (3d-43). The SCG setting information may include addition and cancellation information for SCells to be added to the SCG. In addition, information for further setting the SRB 3 so that the control message generated by the SCG can be transmitted through the SCG base station may be included. In addition, information on a bearer to be transmitted through the SCG may be included. The configuration information can be transmitted using the RRConnectionReconfiguration message of the RRC layer. Thereafter, the UE transmits a message confirming reception of the setup information, which can be transmitted using the RRCConnectionReconfigurationComplete message (3d-45). Accordingly, the UE can simultaneously transmit and receive data using the LTE cell 3d-03, which is an MCG, and the NR cell 3d-05, which is an SCG. When SRB3 is set, the control message can be transmitted / received through the SRB3 (3d- 47) (3d-49). Accordingly, the base station can transmit a setup command to the mobile station through the SRB for setting various functions. However, it may happen that the UE can not follow the setting of the base station in the RRCConnectionReconfiguration message. In this case, the UE determines which bearer has failed. If the bearer is the SRB of the MCG (i.e., SRB1 or SRB2), the UE performs an RRC Connection Reestablishment procedure (not shown in the figure). That is, the UE selects one cell in the neighbor cell through the cell selection procedure, and then attempts to recover the connection by transmitting an RRConnectionReestablishment message of the RRC layer to the corresponding cell. If the bearer is the SRB of the SCG (i.e., SRB3), the UE aborts both transmission of the SCG DRB and transmission of the split DRB to the SCG, and also transmission of the SRB3 and transmission of the split SRB1 / 2 to the SCG -53). In addition, the error is reported to the MCG base station (3d-55). The SCGFailureInformation message of the RRC layer at the time of reporting may be used and information indicating that the cause of the failure is an RRC reset failure may be included in the message. In addition, the PDCP status report of the PDCP layer is generated for the SRB or the DRB that satisfies the following conditions, and the MCG base station is reported to the MCG base station (step 3d-27).

- MCG split DRB or SCG split DRB (or split SRB1 / 2/3)

- DRBs with statusReportRequired set in the DRB

This informs the MCG base station which downlink packet was correctly received and notifies the SCG that the lost data is recoverable.

3E is a diagram illustrating an example of the operation sequence of the terminal when the present invention is applied.

In FIG. 3E, the terminal is connected to the LTE base station, and assumes a state in the connection mode (RRC_CONNECTED) (3e-01).

After receiving the SCG setup information from the base station, the UE transmits a confirmation message (3e-03). The SCG setting information may include addition and cancellation information for SCells to be added to the SCG. In addition, information for further setting the SRB 3 so that the control message generated by the SCG can be transmitted through the SCG base station may be included. In addition, information on a bearer to be transmitted through the SCG may be included. The configuration information can be transmitted using the RRConnectionReconfiguration message of the RRC layer. Thereafter, a message confirming that the UE has received the configuration information can be transmitted using the RRCConnectionReconfigurationComplete message. According to the setting information, the UE can simultaneously transmit and receive data using the MCG and the SCG (3e-05). In addition, when the SRB3 is set, the control message can be transmitted / received through the SRB3.

When the UE transmits / receives data to / from the SRB or DRB as described above, the UE can perform an integrity check on each packet (3e-05). In addition, the UE determines whether the UE can set up the messages received by the SRB (3e-05).

If an error occurs in the SRB or DRB integrity check, or if it is impossible to apply the settings received in the SRB, the UE determines which bearer has encountered the error (3e-07).

If the bearer is the SRB of the MCG (i.e., SRB1 or SRB2) or the MCG DRB (including bearer and MCG split bearer only to MCG), the UE performs an RRC Connection Reestablishment procedure -09). That is, the UE selects one cell in the neighbor cell through the cell selection procedure, and then attempts to recover the connection by transmitting an RRConnectionReestablishment message of the RRC layer to the corresponding cell.

If the bearer is the SRB of the SCG (i.e., SRB3) or the SCG DRB (including the bearer and the SCG split bearer only transmitted to the SCG), the terminal aborts both the transmission of the SCG DRB and the transmission of the split DRB to the SCG, The transmission of the SRB3 and the transmission of the split SRB1 / 2 to the SCG are also interrupted (3e-11). The error is reported to the MCG base station (3e-13). The SCGFailureInformation message of the RRC layer at the time of reporting may be used and information indicating that the cause of the failure is the SRB3 (or SCG DRB) integrity check error or the RRC reset failure may be included in the message. In addition, a PDCP status report of the PDCP layer is generated for SRBs or DRBs satisfying the following conditions, and the MCG base station is reported to the UE through which packet the current packet is correctly received (3e-15).

- MCG split DRB or SCG split DRB (or split SRB1 / 2/3)

- DRBs with statusReportRequired set in the DRB

This informs the MCG base station which downlink packet was correctly received and notifies the SCG that the lost data is recoverable.

FIG. 3F shows a block configuration of a terminal according to an embodiment of the present invention.

3F, the terminal includes a radio frequency (RF) processor 3f-10, a baseband processor 3f-20, a storage 3f-30, and a controller 3f-40 do.

The RF processor 3f-10 performs a function for transmitting and receiving a signal through a radio channel such as band conversion and amplification of a signal. That is, the RF processor 3f-10 up-converts the baseband signal provided from the baseband processor 3f-20 to an RF band signal, and transmits the RF band signal through the antenna, To a baseband signal. For example, the RF processor 3f-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter . In FIG. 3E, only one antenna is shown, but the terminal may have a plurality of antennas. In addition, the RF processor 3f-10 may include a plurality of RF chains. Further, the RF processor 3f-10 may perform beamforming. For the beamforming, the RF processor 3f-10 may adjust the phase and size of signals transmitted and received through a plurality of antennas or antenna elements.

The baseband processor 3f-20 performs a function of converting a baseband signal and a bit string according to a physical layer specification of the system. For example, at the time of data transmission, the baseband processing unit 3f-20 generates complex symbols by encoding and modulating transmission bit streams. Also, upon receiving the data, the baseband processor 3f-20 demodulates and decodes the baseband signal provided from the RF processor 3f-10 to recover the received bitstream. For example, when data is transmitted according to an orthogonal frequency division multiplexing (OFDM) scheme, the baseband processing unit 3f-20 generates complex symbols by encoding and modulating transmission bit streams and outputs the complex symbols to sub- And then constructs OFDM symbols by IFFT (Inverse Fast Fourier Transform) operation and CP (cyclic prefix) insertion. When receiving the data, the baseband processing unit 3f-20 divides the baseband signal provided from the RF processing unit 3f-10 into OFDM symbol units and performs FFT (fast Fourier transform) operation on the subcarriers Restores the mapped signals, and then restores the received bit stream through demodulation and decoding.

The baseband processing unit 3f-20 and the RF processing unit 3f-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 3f-20 and the RF processing unit 3f-10 may be referred to as a transmitting unit, a receiving unit, a transmitting / receiving unit, or a communication unit. Also, at least one of the baseband processing unit 3f-20 and the RF processing unit 3f-10 may include different communication modules for processing signals of different frequency bands. The different frequency bands may include a super high frequency (SHF) band (e.g., 2.5 GHz, 5 GHz), and a millimeter wave (e.g., 60 GHz) band.

The storage unit 3f-30 stores data such as a basic program, an application program, and setting information for operating the terminal.

The controller 3f-40 controls overall operations of the terminal. For example, the control unit 3f-40 transmits and receives signals through the baseband processing unit 3f-20 and the RF processing unit 3f-10. Also, the controller 3f-40 writes and reads data in the storage unit 3f-40. For this, the controller 3f-40 may include at least one processor. For example, the controller 3f-40 may include a communication processor (CP) for controlling communication and an application processor (AP) for controlling an upper layer such as an application program. According to the embodiment of the present invention, the control unit 3f-40 includes a multiple connection processing unit 3f-42 for performing a process for operating in a multiple connection mode. For example, the controller 3f-40 may control the terminal to perform the procedure shown in the operation of the terminal shown in FIG. 3E.

According to the embodiment of the present invention, after the terminal receives the DC from the base station, if the integrity check error or the RRC reset fails, the terminal performs the above operation according to the occurrence of the RB in order to recover the connection.

Methods according to the claims or the embodiments described in the specification may be implemented in hardware, software, or a combination of hardware and software.

When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored on a computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to perform the methods in accordance with the embodiments of the invention or the claims of the present invention.

Such programs (software modules, software) may be stored in a computer readable medium such as a random access memory, a non-volatile memory including a flash memory, a ROM (Read Only Memory), an electrically erasable programmable ROM (EEPROM), a magnetic disc storage device, a compact disc-ROM (CD-ROM), a digital versatile disc (DVDs) An optical storage device, or a magnetic cassette. Or a combination of some or all of these. In addition, a plurality of constituent memories may be included.

In addition, the program may be transmitted through a communication network composed of a communication network such as the Internet, an Intranet, a LAN (Local Area Network), a WLAN (Wide LAN), or a SAN (Storage Area Network) And can be stored in an attachable storage device that can be accessed. Such a storage device may be connected to an apparatus performing an embodiment of the present invention via an external port. In addition, a separate storage device on the communication network may be connected to an apparatus that performs an embodiment of the present invention.

In the concrete embodiments of the present invention described above, the elements included in the invention are expressed singular or plural in accordance with the specific embodiment shown. It should be understood, however, that the singular or plural representations are selected appropriately according to the situations presented for the convenience of description, and the present invention is not limited to the singular or plural constituent elements, And may be composed of a plurality of elements even if they are expressed.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

Claims (1)

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

Images