Communication method and device in wireless communication system

Abstract

The present disclosure relates to a communication method and system for aggregating a fifth generation (5G) communication system with a technology for the Internet of Things (IoT), the 5G communication system being used to support a higher data rate than a fourth generation (4G) system. The present disclosure provides a method performed by a terminal in a wireless communication system, the method comprising: receiving a radio resource control RRC message including first information configuring a medium access control MAC parameter of the terminal from a base station; identifying second information indicating whether the terminal skips uplink transmission, the second information being included in the first information; receiving an uplink grant from the base station on a physical downlink control channel PDCCH addressed to a cell radio network temporary identifier C‑RNTI; and based on the second information, identifying whether to skip generation of a MAC protocol data unit PDU associated with the uplink grant.

Description

[0001] This application is a divisional application of the Chinese patent application with the application date of July 15, 2016, application number 201680042621.3, and invention name “Communication method and device in wireless communication system”. Technical Field

[0002] The present invention relates to a method and apparatus for wireless communication in a wireless communication system. Background Art

[0003] Wireless communication systems that provide voice-based services have evolved into broadband wireless communication systems that can provide high-quality and high-speed packet data-based services, such as: Long Term Evolution (LTE) or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A) or EUTRA Evolution, High Speed ​​Packet Access (HSPA) defined in 3GPP (3rd Generation Partnership Project); Ultra Mobile Broadband (UMB), High Rate Packet Data (HRPD) defined in 3GPP2; Communication standard IEEE 802.16e, etc. LTE-A refers to a system evolved from LTE. In addition to the functions of LTE, LTE-A also includes functions such as Carrier Aggregation (CA), high-order MIMO (Multiple Input Multiple Output), etc. In the following description, the terms LTE and LTE-A will be used with the same meaning unless otherwise specifically indicated.

[0004] LTE and LTE-A systems, which are typical examples of broadband wireless communication systems, adopt Orthogonal Frequency Division Multiplexing (OFDM) in the downlink and Single Carrier-Frequency Division Multiple Access (SC-FDMA) in the uplink. Multiple access performs allocation and management of time-frequency resources carrying data and control information according to users so as not to overlap with each other, that is, to achieve orthogonality between them, thereby distinguishing data or control information between individual users.

[0005] In order to meet the growing demand for wireless data communication volume after the commercialization of 4G communication systems, considerable efforts have been made to develop pre-5G communication systems or improved 5G communication systems. This is one reason why '5G communication systems' or 'pre-5G communication systems' are called 'super 4G network communication systems' or 'post-LTE systems'. In order to achieve high data transmission rates, 5G communication systems are being developed to implement 5G communication systems in extremely high frequency or millimeter wave (mmWave) frequency bands (e.g., 60GHz frequency bands). In order to reduce the occurrence of stray radio waves in extremely high frequency bands and increase the transmission distance of radio waves in 5G communication systems, various technologies are being explored, such as: beamforming, massive MIMO, full dimensional MIMO (FD-MIMO), array antennas, analog beamforming, massive antennas, etc. In order to improve the system network of the 5G communication system, various technologies have been developed, such as: evolved small cells, advanced small cells, cloud radio access network (cloud RAN (radio access network), ultra-dense network, device to device communication (D2D), wireless backhaul, mobile network, cooperative communication, coordinated multi-point (CoMP), interference cancellation, etc. In addition, for the 5G communication system, other technologies have been developed, such as hybrid FSK and QAM modulation (FSK and QAM Modulation, FQAM) and sliding window superposition coding (Sliding Window Superposition Coding, SWSC) as advanced coding modulation (ACM), filter bank multi carrier (Filter Bank Multi Carrier, FBMC), non-orthogonal multiple access (non-orthogonal multiple access, NOMA), sparse code multiple access (sparse code multiple access, SCMA), etc.

[0006] The Internet has evolved from a human-based connected network in which people create and consume information to the Internet of Things (IoT), in which distributed configurations such as objects exchange information with each other to process information. Technologies related to IoT are beginning to be combined with technologies for processing big data, such as through connections to cloud servers, which are called Internet of Everything (IoE) technologies. In order to manifest IoT, various technical components are required, such as sensing technology, wired / wireless communication and network infrastructure technology, service interface technology, security technology, etc. In recent years, sensor networks for connecting objects, machine to machine (Machine to Machine, M2M), machine type communication (Machine Type Communication, MTC), etc. have been studied. In the IoT environment, intelligent Internet technology (IT) services can be provided to collect and analyze data obtained from objects connected to each other, thereby creating new value for human life. As existing information technology is integrated and combined with various industries, IoT can also be applied to various fields, such as: smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, health care, smart home appliances, high-quality medical services, etc.

[0007] Various attempts have been made to apply 5G communication systems to IoT networks. For example, various technologies related to sensor networks, machine-to-machine (M2M), machine type communication (MTC), etc. have been implemented through beamforming, MIMO, array antennas, etc. as 5G communication technologies. The application of the above-mentioned cloud RAN as a big data processing technology can be an example of a hybrid of 5G technology and IoT technology. Wireless communication systems have been developed in software or hardware to provide higher quality communications. For example, communication technology has been developed to adopt multiple antennas. Technology for effectively recovering data from physical signals has made progress.

[0008] In order to meet the growing demand for large communication capacity, a number of technologies have been proposed, such as methods of providing multiple connections. In the Long Term Evolution (LTE) system, carrier aggregation (CA) technology uses multiple carriers to provide multiple connections, allowing users to receive various services via multiple resources. Summary of the invention

[0009] Technical issues

[0010] The present invention has been made to solve the above problems and disadvantages and to provide at least the advantages described below. Various embodiments of the present invention provide a method and apparatus for providing dual connectivity using Radio Access Technologies (RATs) different from each other in a wireless communication system.

[0011] Technical Solution

[0012] According to one aspect of the present disclosure, a method performed by a terminal in a wireless communication system is provided, the method comprising: receiving a radio resource control RRC message including first information configuring a media access control MAC parameter of the terminal from a base station; identifying second information indicating whether the terminal skips uplink transmission, the second information being included in the first information; receiving an uplink grant from the base station on a physical downlink control channel PDCCH addressed to a cell radio network temporary identifier C-RNTI; and based on the second information, identifying whether to skip generation of a MAC protocol data unit PDU associated with the uplink grant.

[0013] According to one aspect of the present disclosure, a terminal in a wireless communication system is provided, the terminal comprising: a transceiver configured to send or receive a signal; and a controller configured to: receive a radio resource control RRC message including first information configuring a media access control MAC parameter of the terminal from a base station, identify second information indicating whether the terminal skips uplink transmission, the second information being included in the first information, receive an uplink grant from the base station on a physical downlink control channel PDCCH addressed to a cell radio network temporary identifier C-RNTI, and based on the second information, identify whether to skip generation of a MAC protocol data unit PDU associated with the uplink grant.

[0014] According to one aspect of the present disclosure, a method performed by a system including a terminal and a base station is provided, the method comprising: a radio resource control RRC message including first information for configuring a media access control MAC parameter of the terminal by the base station to the terminal; and an uplink grant is sent by the base station to the terminal on a physical downlink control channel PDCCH addressed to a cell radio network temporary identifier C-RNTI, wherein whether to skip generation of a MAC protocol data unit PDU associated with the uplink grant is identified by the terminal based on second information included in the first information, and the second information indicates whether the terminal skips uplink transmission.

[0015] According to one aspect of the present disclosure, a system including a terminal and a base station is provided, wherein the base station is configured to: send a radio resource control RRC message including first information configuring a media access control MAC parameter of the terminal to the terminal, and send an uplink grant to the terminal on a physical downlink control channel PDCCH addressed to a cell radio network temporary identifier C-RNTI, and wherein whether to skip generation of a MAC protocol data unit PDU associated with the uplink grant is identified by the terminal based on second information included in the first information, and the second information indicates whether the terminal skips uplink transmission.

[0016] According to one aspect of the present invention, a communication method of a terminal in a wireless communication system is provided. The communication method includes: connecting to a cellular network via a base station; receiving a control message including measurement-related information associated with a wireless local area network (WLAN) from the base station; and measuring the WLAN based on the measurement-related information.

[0017] According to another aspect of the present invention, a communication method of a base station in a wireless communication system is provided. The communication method includes: connecting a terminal to a cellular network; and sending a control message including measurement-related information associated with a wireless local area network (WLAN) to the terminal.

[0018] According to another aspect of the present invention, a terminal in a wireless communication system is provided. The terminal includes: a transceiver configured to perform signal transmission / reception; and a controller configured to connect to a cellular network via a base station; receive a control message including measurement-related information associated with a wireless local area network (WLAN) from the base station; and measure the WLAN based on the measurement-related information.

[0019] According to another aspect of the present invention, a base station in a wireless communication system is provided. The base station includes: a transceiver configured to perform signal transmission / reception; and a controller configured to: connect a terminal to a cellular network; and send a control message including information related to measurements associated with a wireless local area network (WLAN) to the terminal.

[0020] Advantageous Effects of the Invention

[0021] According to various embodiments of the present invention, a method and an apparatus can perform measurement using radio access technologies (RATs) different from each other in a wireless communication system, and can also ensure compatibility with a version of the RAT to be developed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other aspects, features, and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1 is a diagram showing a network configuration of a wireless communication system according to Embodiment 1 of the present invention;

[0024] Figure 2 is a diagram showing a radio protocol stack in an LTE system according to the present invention;

[0025] Figure 3 is a flowchart showing a message flow between a UE (User Equipment) and an eNB using a measurement object indicator for WLAN according to Embodiment 1 of the present invention;

[0026] Figure 4 is a flowchart describing a method for a UE to calculate a measurement object frequency when the UE receives a measurement object indicator for a WLAN according to embodiment 1 of the present invention;

[0027] Figure 5 is a block diagram showing the configuration of a UE in a wireless communication system according to Embodiment 1 of the present invention;

[0028] Figure 6 is a block diagram showing an ENB in ​​a wireless communication system according to Embodiment 1 of the present invention;

[0029] Figure 7 is a diagram showing a configuration of an LTE system according to the present invention;

[0030] Figure 8 is a diagram showing a radio protocol stack in an LTE system according to the present invention;

[0031] Fig. 9 is a flowchart describing operations between a UE and an ENB according to Embodiment 2-1;

[0032] Fig.10 is a flowchart describing the operation of the UE according to Embodiment 2-1;

[0033] Fig.11 is a flowchart describing operations between a UE and an ENB according to Embodiment 2-2;

[0034] Fig.12 is a flowchart describing the operation of the UE according to Embodiment 2-2;

[0035] Fig.13 is a flowchart describing operations between a UE and an ENB according to Embodiment 2-3;

[0036] Fig.14 is a flowchart describing the operation of the UE according to Embodiment 2-3;

[0037] Fig.15 is a block diagram showing a configuration of a UE in a wireless communication system according to Embodiment 2; and

[0038] Fig.16 is a block diagram showing the configuration of an ENB in ​​a wireless communication system according to Embodiment 2. DETAILED DESCRIPTION

[0039] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are used throughout the accompanying drawings to refer to the same or similar parts. Detailed descriptions of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of the present invention.

[0040] In the following description, some embodiments of the present invention will be described based on advanced E-UTRA (also known as LTE-A) supporting carrier aggregation; however, those skilled in the art will appreciate that the subject matter of the present invention can also be applied to various types of communication systems having a technical background and channel form similar to that of the present invention without departing from the scope and spirit of the present invention. For example, the subject matter of the present invention can be applied to multi-carrier HSPA supporting carrier aggregation.

[0041] In the following description, certain detailed descriptions of the related art are omitted when it is deemed that they would unnecessarily obscure the essence of the present invention.

[0042] Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated or omitted in order to better illustrate and explain the present invention. The same reference numerals are used throughout the drawings to refer to the same or similar parts.

[0043] From the following detailed description in conjunction with the accompanying drawings, the features and advantages of the present invention and the methods for achieving them will become more apparent. It will be readily appreciated by those skilled in the art that various modifications, additions and substitutions are possible from the embodiments of the present invention illustrated and described in detail in the following description, and the scope of the present invention should not be limited to the following embodiments. Embodiments of the present invention are provided so that those skilled in the art fully understand the present invention. It should be understood that the present invention may include all modifications and / or equivalents and / or substitutions included in the thought and technical scope of the present disclosure. In the accompanying drawings, even if the same or similar elements are depicted in different drawings, they are represented by the same reference numerals.

[0044] In addition, it should be understood that the process, operation and combination of the flowchart can be performed via computer programming instructions. These computer programming instructions can be installed to a processor, a special computer or a general-purpose computer of a data processing device that can be programmed. The instructions executed via the processor of a data processing device or a computer can generate a device for performing the function described in the frame of the flowchart. In order to realize the function in a specific mode, the computer programming instructions can also be stored in a computer-usable memory or a computer-readable memory that can support a computer or a data processing device that can be programmed. Therefore, the instructions stored in the computer-usable memory or the computer-readable memory can be installed to the product, and the functions described in the frame of the flowchart therein are performed. In addition, because the computer programming instructions can also be installed to a computer or a data processing device that can be programmed, they can create a process for performing a series of operations therein, which is described in the frame of the flowchart therein.

[0045] The frame of the flow chart refers to the code, segment or part of the module including one or more executable instructions for performing one or more logical functions. It should be noted that the functions described in the frame of the flow chart can be performed in an order different from the above-mentioned embodiment. For example, the functions described in two adjacent frames can be performed simultaneously or in reverse order.

[0046] In an embodiment, the term '~unit' representing a component refers to a software element or hardware element such as an FPGA, an ASIC (Application Specific Integrated Circuit), etc. and performs a corresponding function. However, it should be understood that the component '~unit' is not limited to a software or hardware element. The component '~unit' can be implemented in a storage medium that can be specified by an address. The component '~unit' can also be configured to regenerate one or more processors. For example, the component '~unit' can include various types of elements (e.g., software elements, object-oriented software elements, class elements, task elements, etc.), fragments (e.g., processes, functions, implementations, attributes, programs, subroutines, program codes, etc.), drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, variables, etc. The functions provided by the elements and components '~units' can be formed by combining a small number of elements and components '~units', or can be divided into additional elements and components '~units'. In addition, the elements and components '~units' can also be implemented to regenerate one or more CPUs in a device or a secure multi-card.

[0047] <Example 1>

[0048] Embodiment 1 relates to a technology for providing dual connectivity to a wireless communication system.

[0049] In the following description, for the convenience of description, terms for identifying access nodes, terms called network entities, terms expressing messages, terms indicating interfaces between network objects, terms for various types of identification information, etc. are used. Therefore, the present invention is not limited by the terms, and other terms having equivalent meanings to the terms indicating corresponding components described in the present disclosure may be used.

[0050] For the convenience of description, the present disclosure uses the terms and names defined in the specifications of the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) and the Institute of Electrical and Electronic Engineers (IEEE) 802.11. However, it should be understood that the present invention is not limited to these terms and names, and can also be applied to systems that comply with other standards.

[0051] The following description explains an embodiment of the present invention for providing dual connectivity using Wireless Local Area Network (WLAN) technology in a cellular communication system. However, it should be understood that the present invention may also be applied to Radio Access Technologies (RATs).

[0052] Figure 1 is a diagram showing a network configuration of a wireless communication system according to an embodiment of the present invention.

[0053] refer to Figure 1 , the wireless communication system includes eNB A (110-1), eNB B (110-2), eNB C (110-3), mobility management entity (MME) / serving-gateway (S-GW) 120-1 and 120-2, and access point (AP) 150. Although the embodiment is described based on three eNBs, it should be understood that the embodiment can also be modified in a manner including two eNBs or four or more eNBs. MME / S-GW 120-1 and 120-2 can be separated into MME and S-GW.

[0054] The eNBs 110-1, 110-2, and 110-3 are referred to as access nodes of a cellular network and provide wireless access to UE devices to connect to the network. That is, the eNBs 110-1, 110-2, and 110-3 support connections between UE devices and a core network. According to various embodiments of the present invention, the eNB A (110-1) provides dual connectivity to the UE via the AP 150.

[0055] The MME / S-GW 120-1 and 120-2 manage the mobility of the UE. The MME / S-GW 120-1 and 120-2 may also perform authentication for the UE to connect to the network, bearer management, etc. The MME / S-GW 120-1 and 120-2 process packets transmitted from the eNB 220 or packets forwarded to the eNBs 110-1, 110-2, and 110-3.

[0056] AP 150 is an access node of WLAN and provides wireless access to UE devices. In particular, according to various embodiments of the present invention, according to the control of eNB A (110-1), AP 150 is able to provide UE with a WLAN-based connection for dual connectivity. According to various embodiments of the present invention, AP 150 may be included in eNB A (110-1) or may be connected to eNB A (110-1) via a separate interface. In this case, eNB A (110-1) is able to: send part of the downlink data to the UE; or send other data to the UE via AP 150. The UE is able to: send part of the uplink data to eNB A (110-1); and send other data to AP 150.

[0057] The UE is able to connect to the cellular network via eNB A (110-1). According to an embodiment of the present invention, eNB A (110-1) additionally sets the UE to connect to AP 150, thereby enabling the UE to communicate over a wider frequency band. Although the core network entity (e.g., MME, S-GW, packet data network gateway (P-GW), etc.) does not recognize that dual connectivity has been set by additionally using AP 150 in the wireless area, it can provide services. In this case, dual connectivity is referred to as LTE-WLAN aggregation (or carrier aggregation (CA) or integration).

[0058] When an entity provides dual connectivity via AP 150, it is necessary to determine the connection for sending data. For example, in the case of a downlink, eNB A (110-1) receives data from the core network and determines whether it will send the data directly or via WLAN. In the case of an uplink, the UE determines a path for sending data and sends the data to the core network.

[0059] Figure 2 is a diagram of a radio protocol stack in an LTE system according to the present invention.

[0060] refer to Figure 2, the UE and the ENB have a Packet Data Convergence Protocol (PDCP) 205 and 240, a Radio Link Control (RLC) 210 and 235, and a Medium Access Control (MAC) 215 and 230, respectively. The PDCP 205 and 240 compress / decompress the IP header. The RLC 210 and 235 reconfigure the PDCP packet data unit (PDU) with an appropriate size. The MAC 215 and 230 are connected to multiple RLC layer devices configured in one UE device. The MAC 215 and 230 multiplex the RLC PDU to the MAC PDU and demultiplex the RLC PDU from the MAC PDU. The Physical layer (PHY) 220 and 225 in the UE and the eNB channel codes and modulates the data from the higher layer, creates OFDM symbols, and transmits them via a wireless channel. In addition, PHY 220 and 225 demodulate and channel decode the OFDM symbols received via the wireless channel and transmit them to a higher layer. In addition, PHY uses hybrid ARQ (Hybrid ARQ, HARQ) to perform additional error correction. The receiver sends a 1-bit signal to the transmitter for the condition as to whether it has received the packet sent from the transmitter, which is called HARQ ACK / NACK information. The downlink HARQ ACK / NACK information sent in response to the uplink is sent via a physical channel (Physical Hybrid-ARQ Indicator Channel (PHICH)). The uplink HARQ ACK / NACK information sent in response to the downlink is sent via a physical channel (Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH)).

[0061] Figure 3 is a flow chart illustrating a message flow between a UE and an eNB using a measurement object indicator for a WLAN according to the present invention.

[0062] In the embodiment, it is assumed that UE 301 is connected to LTE eNB 303 (RRC_CONNECTED). In this case, UE and eNB can transmit / receive data to / from each other.

[0063] In operation 311, the eNB 303 can send a message to the UE 301 instructing to measure a nearby WLAN in order to configure interworking operation or integration / aggregation between LTE and WLAN. The measurement instruction message may include measurement object information and report configuration information about the time and form of reporting the corresponding measurement object. The details of the measurement object may include a WLAN AP identifier (e.g., SSID (Service Set Identifier), BSSID (Basic SSID), etc.) and / or a WLAN frequency. In an embodiment, the eNB can instruct the UE to measure the WLAN frequency by combining the following items:

[0064] ·nation

[0065] Operating Class

[0066] Channel number

[0067] The IEEE 802.11 specification, which is a WLAN standard, defines an operation class and a channel set of channel numbers in the operation class according to countries. In the case of the US, part of the operation class is defined as shown in Table 1 below.

[0068] [Table 1]

[0069]

[0070] The WLAN channel frequency is calculated according to the following equation with reference to Table 1.

[0071] Channel center frequency = channel start frequency + 5 × nch (MHz),

[0072] Where nch=1,...,200.

[0073] In the case of {country, operation category, channel number}={US, 4, 120}, this means that the country is US and the operation category is number 4. Therefore, referring to item number 4 of the operation category in Table 4, the channel start frequency is 5 GHz=5000 MHz. In addition, since the channel number is 120, the frequency of the actual channel is 5600 MHz (=5000+5×120).

[0074] When all items (country, operating category and channel number) are used, only one frequency may be indicated. When country and operating category are used, the UE is instructed to measure all operating categories in the channel set. For example, when the UE is signaled that {country, operating category, channel number} = {US, 4, 120}, only the frequency of 5600 MHz may be indicated. When the UE is signaled that {country, operating category} = {US, 4}, a total of 11 frequencies may be indicated to be measured, namely 5500, 5520, ..., 5700 MHz.

[0075] The individual fields (country, operating class, and channel number) may be signaled by the following methods.

[0076] ·nation

[0077] Option 1: 3 octets (as a bit string; according to ISO / IEC 3166-1); or

[0078] Choice 2: N-bit or 1-octet integer

[0079] Operation category

[0080] 1 octet integer

[0081] Channel number

[0082] Option 1: A list of integers for each channel

[0083] Option 2: Variable-sized bitmaps depending on the type of operation

[0084] For example, according to the ISO / IEC 3166-1 specification defined in the IEEE standard, the country field can be encoded with 3 bytes. That is, the country or non-country entity in which the UE / WLAN Ap is running can be identified with 3 bytes. For the country entity, the first and second octets of the string correspond to the two country codes described in ISO / IEC 3166-1, and the third octet corresponds to one of the following:

[0085] ASCII space character (when the specification for the operation of the UE / WLAN AP includes all environments in the current frequency band of the country),

[0086] ASCII 'O' character (when the provision of UE / WLAN AP operation is relevant to outdoor environment),

[0087] ASCII 'I' character (when the provision of UE / WLAN AP operation is relevant to indoor environment),

[0088] ASCII 'X' characters (when the UE / WLAN AP operates in a non-state entity, the first and second octets of the non-state entity correspond to two ASCII 'XX' characters),

[0089] The binary representation of the table number (see Table 1) of the operation category is used.

[0090] In the current IEEE standard, the country field is defined for only four countries. Therefore, the country field can be in a two-bit format (representing four countries: 00, 01, 10, 11) or a 1-byte integer format.

[0091] Alternatively, for the country field, when the Mobile Country Code (MCC) contained in the Public Land Mobile Network Identity PLMNID (Public Land Mobile Network Identity) of the LTE eNB is used, the transmission can be omitted. For example, in a state where the System Information Block (SIB) broadcast by the LTE eNB to the UE in the coverage area carries the MCC information in the PLMN, and the MCC information is a value corresponding to the US (i.e., 310, 311, 312, 313, 314, 315, 316), when the UE is instructed to measure the WLAN frequency without information about the country, the UE can calculate the measured frequency assuming that the country value is a value corresponding to the US. The MCC value is defined in COMPLEMENT TOITU-T RECOMMENDATION E.212 (11 / 98) of ITU-T.

[0092] For example, the operation class may be in the format of a 1-byte integer.

[0093] The field of the channel number can be in the format of a list of 1-byte integers for each channel. For example, the channel number of {country, operating category} = {US, 4} can be indicated in the format of {100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140}. When the above format is used and 11 channel numbers are adopted, 11 bytes of resources are required. In order to reduce bytes, a bitmap format according to the operating category can be considered. For example, when indicating all channel numbers of {country, operating category} = {US, 4}, because the number of channels of {country, operating category} = {US, 4} is 11, it can therefore be indicated using a bitmap with a length of 11 bits. An example of a bitmap is as follows.

[0094] 1 1 1 1 1 1 1 1 1 1 1

[0095] For example, when indicating two channel numbers of {country, operation category}={US, 4}, that is, {120, 140}, since the number of channels of {country, operation category}={US, 4} is 11, it can adopt a bitmap with a length of 11 bits, and can be indicated in a manner that the number of bits to be indicated is set to '1'. An example of the bitmap is as follows.

[0096] 0 0 0 0 0 1 0 0 0 0 1

[0097] For example, when indicating all channel numbers of {country, operation category} = {US, 1}, since the number of channels of {country, operation category} = {US, 1} is 4, it can be indicated using a bitmap with a length of 4 bits, thereby instructing the UE to efficiently indicate the measurement frequency. An example of the bitmap is as follows.

[0098]

[0099] When the measurement frequency is indicated using the country, operation class, and channel number, the country, operation class, and channel number values ​​can be used in future IEEE standards to define the frequency to be used for WLAN without change. Therefore, this method is advantageous because it can indicate the frequency to be measured for WLAN defined in the new IEEE standard without changing the specification of the 3GPP standard.

[0100] exist Figure 3 The report configuration information included in the measurement instruction message sent in operation 311 enables the UE to report the measurement results of the measurement object periodically or when a specified condition is met. Examples of the specified conditions are as follows:

[0101] Event A1: The service becomes better than the absolute threshold.

[0102] Event A2: The service becomes worse than the absolute threshold.

[0103] • Event A3: The neighbor becomes better than the PCell by an offset.

[0104] • Event A4: The neighbor becomes better than an absolute threshold.

[0105] Event A5: Pcell becomes worse than an absolute threshold 1 and the neighbor becomes better than another absolute threshold 2.

[0106] Event A6: The neighbor becomes better than the SCell by an offset.

[0107] That is, when the level of signal strength / quality of the current LTE cell is greater than or less than a threshold or the level of signal strength / quality in a neighboring cell (or WLAN) is greater than or less than a threshold, the UE may perform a reporting operation to the eNB. The measurement instruction message may be sent via a radio resource control (RRC) layer message RRCConnectionReconfiguration. When the UE receives the RRCConnectionReconfiguration message in operation 311, in operation 313, it sends a confirmation message (e.g., RRCConnectionReconfigurationComplete) of successful reception of the notification message (i.e., RRC layer message) to the eNB.

[0108] In operation 315, the UE measures the neighboring WLAN signal according to the instruction. The UE may measure the neighboring WLAN signal using the beacon message sent from the WLAN AP 305. When the UE has measured the signal and determines that the reporting condition configured in operation 311 is met, it reports the measurement result to the eNB in ​​operation 321. The UE may report the measurement result using an RRC layer message, such as MeasurementReport.

[0109] When receiving the report message of the measurement result, the eNB can send a message to the UE for instructing the UE to additionally use or move to the WLAN, taking into account the reported signal strength / quality, etc., so that in operation 323, the UE can perform interworking operations or integration / aggregation with the reported WLAN AP. The instruction message may include an identifier of the WLAN as the destination, such as an SSID, a BSSID, etc. The instruction message may be sent via an RRC layer message RRCConnectionReconfiguration. In operation 325, when the UE receives the message, it sends a confirmation message (e.g., RRCConnectionReconfigurationComplete) of the successful reception of the notification message (i.e., the RRC layer message) to the eNB.

[0110] Figure 4 The present invention is a flowchart describing a method in which a UE calculates a measurement object frequency when the UE receives a measurement object indicator for a WLAN according to the present invention.

[0111] In operation 403, the UE can receive an RRC message for instructing measurement of the WLAN from the eNB. In operation 405, the UE can determine whether the measurement object information indicating the measurement frequency included in the measurement instruction message includes information about the country. When the UE determines in operation 405 that the measurement object information includes information about the country, it uses the value of the included country in operation 407. On the other hand, when the UE determines in operation 405 that the measurement object information does not include information about the country, it can calculate the value of the country by using the MCC information in the identifier PLMN ID of the service provider of the SIB broadcasted by the LTE eNB to the UE in the coverage area in operation 409. For example, in a state where the MCC information in the PLMN ID corresponds to the US value (i.e., 310, 311, 312, 313, 316), when the UE is instructed to measure the WLAN frequency without information about the country, the UE can calculate the measurement frequency assuming that the country value is a value corresponding to the US.

[0112] When the information about the country is determined as in operation 407 or 409 , in operation 411 , the UE can use the operation class included in the measurement object.

[0113] When the measurement object information includes information about an explicit channel number in operation 413, the UE can calculate a measurement frequency for a channel number indicated within an operation category corresponding to the received or calculated value of the country in operation 415. The calculation of the measurement frequency refers to the calculation of the measurement frequency via Figure 3 The method described in the flowchart shown. When the measurement object information does not include information about the explicit channel number, the UE can calculate the measurement frequency in all channel sets within the operation category corresponding to the received or calculated country value in operation 417. In operation 421, the UE can perform measurement on the calculated frequency (multiple frequencies).

[0114] Figure 5 is a block diagram showing a configuration of a UE in a wireless communication system according to an embodiment of the present invention.

[0115] refer to Figure 5 The UE includes a Radio Frequency (RF) processing unit 510, a baseband processing unit 520, a storage unit 530 and a controller 540.

[0116] The RF processing unit 510 performs functions related to the transmission / reception of signals via a wireless channel, such as conversion of frequency bands, amplification, etc. The RF processing unit 510 up-converts the baseband signal output from the baseband processing unit 520 into an RF band signal and transmits the RF signal via an antenna. The RF processing unit 510 down-converts the RF band signal received via the antenna into a baseband signal. The RF processing unit 510 can include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter (ADC), etc. Although in Figure 5 The embodiment is shown so that the UE includes only one antenna, but it should be understood that the UE can be implemented to include multiple antennas. The RF processing unit 510 can also be implemented to include multiple RF chains. The RF processing unit 510 is capable of performing beamforming operations. In order to perform the beamforming function, the RF processing unit 510 is capable of adjusting the phase and amplitude of individual signals sent / received via multiple antennas or antenna elements.

[0117] The baseband processing unit 520 performs conversion between baseband signals and bit streams according to the physical layer specification of the system. For example, in data transmission, the baseband processing unit 520 encodes and modulates the transmission bit stream to create complex symbols. In data reception, the baseband processing unit 520 demodulates and decodes the baseband signal output from the RF processing unit 510 to recover the received bit stream. For example, in data transmission according to orthogonal frequency division multiplexing (OFDM), the baseband processing unit 520 encodes and modulates the transmission bit stream to create complex symbols, maps the complex symbols to subcarriers, and configures OFDM symbols by inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In data reception, the baseband processing unit 520 separates the baseband signal output from the RF processing unit 510 into OFDM symbol units, recovers the signal mapped to the subcarrier by fast Fourier transform (FFT) operation, and then recovers the received bit stream by demodulation and decoding operations.

[0118] The baseband processing unit 520 and the RF processing unit 510 perform the transmission and reception of signals as described above. Therefore, the baseband processing unit 520 and the RF processing unit 510 may also be referred to as a transmitter, a receiver, a transceiver, a communication unit, etc. In addition, the baseband processing unit 520 and / or the RF processing unit 510 may include a plurality of communication modules to support wireless access technologies that are different from each other. Alternatively, the baseband processing unit 520 and / or the RF processing unit 510 may include different communication modules to process signals of different frequency bands. Examples of wireless access technologies are: wireless LAN (e.g., IEEE 802.11), cellular networks (e.g., LTE), etc. Examples of different frequency bands are: ultra high frequency (SHF) (e.g., 2.5 GHz band, 5 GHz band, etc.), millimeter wave (mmW) (e.g., 60 GHz band), etc.

[0119] The storage unit 530 stores default programs, applications, settings, data, etc. for operating the UE. In particular, the storage unit 530 can store information related to a second access node (e.g., AP) that performs wireless communication using a second wireless access technology (e.g., WLAN network). The storage unit 530 provides the stored data according to a request of the controller 540.

[0120] The controller 540 controls all operations of the UE. For example, the controller 540 controls the baseband processing unit 520 and the RF processing unit 510 to perform signal transmission / reception. The controller 540 controls the storage unit 530 to store / read data therein / from it. To this end, the controller 540 can include at least one processor. For example, the controller 540 can include a communication processor (CP) for controlling communication and an application processor (AP) for controlling a higher layer such as an application. According to an embodiment of the present invention, the controller 540 can include a dual connection processing unit 542 for processing operations in a dual connection mode. For example, the controller 540 can control the UE to perform the above reference Figure 2 Functions and procedures described. In an embodiment, the controller 540 performs the following operations.

[0121] According to an embodiment of the present invention, under the control of the controller 540, the UE can execute Figure 3 For example, when the controller 540 receives a WLAN measurement instruction message from the eNB, it uses Figure 4 The method shown analyzes the message, calculates the frequency to be measured, and performs measurement on the calculated frequency. When the controller 540 determines that the preset condition is satisfied based on the report configuration information included in the measurement instruction message, it can report the measurement result to the eNB.

[0122] Figure 6 is a block diagram illustrating an ENB in ​​a mobile communication system according to an embodiment of the present invention.

[0123] like Figure 6 As shown, the ENB includes an RF processing unit 610 , a baseband processing unit 620 , a backhaul communication unit 630 , a storage unit 640 , and a controller 650 .

[0124] The RF processing unit 610 performs functions related to the transmission / reception of signals via a wireless channel, such as conversion of frequency bands, amplification, etc. The RF processing unit 610 up-converts the baseband signal output from the baseband processing unit 620 into an RF band signal and transmits the RF signal via an antenna. The RF processing unit 610 down-converts the RF band signal received via the antenna into a baseband signal. The RF processing unit 610 can include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although in Figure 6 The embodiment shown in the figure makes the ENB include only one antenna, but it should be understood that the ENB can be implemented to include multiple antennas. The RF processing unit 610 can also be implemented to include multiple RF chains. The RF processing unit 610 is capable of performing beamforming operations. In order to perform the beamforming function, the RF processing unit 610 is capable of adjusting the phase and amplitude of the individual signals sent / received via multiple antennas or antenna elements.

[0125] The baseband processing unit 620 performs conversion between a baseband signal and a bit stream according to the physical layer specification of the first wireless access technology (e.g., a cellular network). For example, in data transmission, the baseband processing unit 620 encodes and modulates the transmission bit stream to create a complex symbol. In data reception, the baseband processing unit 620 demodulates and decodes the baseband signal output from the RF processing unit 610 to restore the received bit stream. For example, in data transmission according to orthogonal frequency division multiplexing (OFDM), the baseband processing unit 620 encodes and modulates the transmission bit stream to create a complex symbol, maps the complex symbol to a subcarrier, and configures the OFDM symbol by an inverse fast Fourier transform (IFFT) operation and a cyclic prefix (CP) insertion. In data reception, the baseband processing unit 620 separates the baseband signal output from the RF processing unit 610 into OFDM symbol units, restores the signal mapped to the subcarrier by a fast Fourier transform (FFT) operation, and then restores the received bit stream by a demodulation and decoding operation. The baseband processing unit 620 and the RF processing unit 610 perform transmission and reception of signals as described above. Therefore, the baseband processing unit 620 and the RF processing unit 610 may also be referred to as a transmitter, a receiver, a transceiver, a communication unit, a wireless communication unit, etc.

[0126] The backhaul communication unit 630 provides an interface to communicate with other nodes in the network. That is, the backhaul communication unit 630: converts the bitstream into a physical signal to be sent to other nodes of the ENB (e.g., another access node, core network, etc.); and converts the physical signal received from the node into a bitstream.

[0127] The storage unit 640 stores default programs, applications, settings, data, etc. for operating the ENB. In particular, the storage unit 640 can store information about a bearer assigned to a connected UE, a measurement result reported from a connected UE, etc. The storage unit 640 can provide a dual connection function to the UE or store reference information to determine whether the ENB terminates the dual connection operation. The storage unit 640 provides the stored data according to a request of the controller 650.

[0128] The controller 650 controls all operations of the ENB. For example, the controller 650 controls the baseband processing unit 620, the RF processing unit 610, and the backhaul communication unit 630 to perform signal transmission / reception. The controller 650 controls the storage unit 640 to store / read data therein / from it. To this end, the controller 650 can include at least one processor. In an embodiment, the controller 650 performs the following operations.

[0129] According to an embodiment of the present invention, the eNB can instruct the UE to measure the frequency via a measurement instruction message including at least one of the following: country, operation category, and channel number under the control of the controller 650. In this case, in order to reduce the consumption of transmission resources, the eNB can create and send a measurement instruction message that does not include a country or a channel number. The measurement instruction message may also include report configuration information.

[0130] <Example 2>

[0131] refer to Figure 7, the LTE system configures a wireless access network, including evolved node Bs (referred to as ENBs, eNBs, node Bs, or base stations) 705, 710, 715, and 720, a mobility management entity (MME) 725, and a serving gateway (S-GW) 730. A user equipment (UE) (also referred to as a terminal) 735 is connected to an external network via ENBs 705, 710, 715, or 720 and S-GW 730. ENBs 705 to 720 correspond to existing node Bs of a universal mobile telecommunications system (UMTS). ENBs 705 to 720 are connected to UEs 735 via wireless channels and are capable of performing more complex functions than existing node Bs. In the LTE system, because real-time services such as voice over Internet protocol (VoIP) services and all user traffic are served via shared channels, it is necessary for the device to collect information about the status, such as the buffer status of the UE device, the available transmission power status, the channel status, etc., and perform scheduling. This task is performed via ENBs 705 to 720. One ENB controls multiple cells. For example, in order to achieve a transmission rate of 100 Mbps, the LTE system adopts Orthogonal Frequency Division Multiplexing (OFDM) as a wireless access technology at a bandwidth of 20 MHz. It also adopts Adaptive Modulation & Coding (AMC) to determine the modulation scheme and channel coding rate that conform to the channel state of the UE. The S-GW 730 is a device that provides data bearers. The S-GW 730 establishes or removes data bearers according to the control of the MME 725. The MME 725 manages the mobility of the UE and controls various functions. The MME 725 is connected to multiple ENBs 705 to 720.

[0132] refer to Figure 8 , the UE and the ENB have a packet data convergence protocol (PDCP) 805 and 840, a radio link control (RLC) 810 and 835, and a medium access control (MAC) 815 and 830, respectively. The PDCP 805 and 840 compress / decompress the IP header. The RLC 810 and 835 reconfigure the PDCP packet data unit (PDU) with an appropriate size and perform an automatic repeat request (ARQ) operation. The MAC 815 and 830 are connected to a plurality of RLC layer devices configured in one UE device. The MAC 815 and 830 multiplex the RLC PDU into the MAC PDU and demultiplex the RLC PDU from the MAC PDU. The physical layer (PHY) 820 and 825 in the UE and the ENB channel codes and modulates the data from the higher layer, creates OFDM symbols, and transmits them via a wireless channel. In addition, the PHY 820 and 825 demodulate and channel decode the OFDM symbols transmitted via the wireless channel and transmit them to a higher layer.

[0133] Dynamic pre-allocation is considered as one of the delay reduction schemes.

[0134] Pre-allocation is a technique that allows the ENB (although it has not received a transmit resource request from the UE) to allocate uplink transmit resources to the UE. Pre-allocation causes a problem in that the ENB (although it has not received a transmit resource request) allocates uplink transmit resources to a UE that has no data to send.

[0135] In the current specification (rule), when the UE is assigned an uplink grant, it is forced to create and send a padding MAC PDU even though the UE has no data to send. A padding MAC PDU is a MAC PDU that includes only padding bits and a padding BSR (Buffer Status Report) but no meaningful data. The rule is defined assuming that the frequency of occurrence of a padding MAC PDU is very low.

[0136] The transmission rule of filling MAC PDU is advantageous because it helps ENB control uplink transmission power and simplifies the implementation of related ENB. When ENB controls the transmission power of UE device, it refers to the statistics of the occurrence of HARQ ACK / NACK message in response to MAC PDU sent from UE. For example, when HARQ NACK never occurs, it means that the current transmission power control method is appropriate. On the contrary, when HARQ NACK occurs relatively frequently, it means that the uplink transmission power control method currently used needs to be modified. Embodiments of the present invention provide new operations to UEs that are allocated resources but do not perform transmission because they have no data to send, thereby efficiently using pre-allocation. Because traditional ENBs expect reverse transmission when allocating resources, traditional ENBs preferably do not adopt the above-mentioned new operations. In the following description, for convenience, when transmission resources are available, uplink transmission is performed unconditionally, which is referred to as unconditional transmission operation. In addition, although transmission resources are available, uplink transmission is performed only when preset conditions are met, which is referred to as conditional transmission operation.

[0137] <Example 2-1>

[0138] In various embodiments of the present invention, the UE selectively adopts an unconditional sending operation or a conditional sending operation according to an instruction of the ENB.

[0139] It is necessary to cooperate with the implicit release operation of Semi-Persistent Scheduling (SPS) to determine the conditions for whether the UE adopts unconditional transmission operation or conditional transmission operation. Implicit release means that when the transmission of a MAC PDU without a MAC SDU (hereinafter referred to as 'zero MAC SDU MACPDU') is performed via the SPS transmission resource for n consecutive times ('n' refers to a positive integer), the UE is enabled to release the configured uplink grant. The implicit release is introduced to prevent the loss of the SPS release signal.

[0140] When the UE has no higher layer data to send, a zero MAC SDU MAC PDU is created. Therefore, when the UE adopts conditional send operation, the implicit release no longer works, which is disadvantageous. The current standard has been defined to ensure that the implicit release is set for the use of SPS.

[0141] Various embodiments of the present invention can selectively apply a conditional transmission operation to SPS transmission resources or normal transmission resources in consideration of conditions regarding whether SPS is configured.

[0142] Fig. 9 is a flowchart describing operations between a UE and an ENB according to Embodiment 2-1.

[0143] In a mobile communication system including UE 905, ENB 910 and other nodes, in operation 915, the UE establishes an RRC connection with the ENB. Establishing an RRC connection between the ENB and the UE means that the ENB and the UE configure a signaling radio bearer (SRB) SRB between them, thereby exchanging RRC control messages with each other. The RRC connection is established via a random access procedure in such a way that: the UE sends an RRC connection establishment request message to the ENB; the ENB sends an RRC connection establishment message to the UE; and the UE sends an RRC connection establishment completion message to the ENB.

[0144] After establishing the RRC connection, the ENB 910 can instruct the UE 905 to perform RRC connection reconfiguration in operation 920. The ENB can send SPS configuration information to the UE via the RRC connection reconfiguration message and indicate to the UE the condition as to whether the conditional transmission operation is adopted. The information indicating the condition as to whether the UE adopts the conditional transmission operation may be included in the lower information of the sps-ConfigUL or MAC-MainConfig of the RRCConnectionReconfiguration message, and may be defined as the format of ENUMERATED{SETUP}, referred to as SkipUplinkTransmission(SkipULTx). For example, when the sps-ConfigUL or MAC-MainConfig of the RRCConnectionReconfiguration message received by the UE includes the SkipUplinkTransmission(SkipULTx) indicated by SETUP, it means instructing the UE to perform the conditional transmission operation. On the other hand, when the sps-ConfigUL or MAC-MainConfig of the RRCConnectionReconfiguration message does not include SkipUplinkTransmission (SkipULTx), it means instructing the UE to perform an unconditional transmission operation.

[0145] SPS configuration information is defined as follows.

[0146]

[0147]

[0148] [Table 1]

[0149]

[0150]

[0151]

[0152] [Table 2]

[0153]

[0154] When the uplink transmission resources allocated for new transmission are available in operation 925, the UE determines whether to perform uplink transmission in operation 930. The uplink transmission resources allocated to the new transmission may be transmission resources allocated by the PDCCH addressed via the C-RNTI of the UE or transmission resources for SPS, that is, the configured UL grant.

[0155] UE: considers conditions regarding the existence of SPS-ConfigUL (first information) and SkipUplinkTransmission (second information), characteristics of available transmission resources, conditions regarding whether there is uplink data to be sent, characteristics of the uplink data to be sent, etc., to determine whether it performs transmission via the uplink transmission resources (or whether it creates a MAC PDU to be sent via the uplink transmission resources); and performs or does not perform uplink transmission based on the determination in operation 930.

[0156] Fig.10 is a flowchart describing the operation of the UE according to Embodiment 2-1.

[0157] In operation 1005 , the UE receives a control message RRCConnectionReconfiguration.

[0158] In operation 1010, the UE determines whether the IE of the control message includes second control information.

[0159] When the UE determines in operation 1010 that the IE of the control message includes the second control information, it determines in operation 1015 to apply the conditional transmission operation to the transmission and wait until a time when a new uplink transmission can be performed. When a new uplink transmission can be performed (for example, when a configured uplink grant is available or an uplink grant is received via the PDCCH), the UE proceeds to operation 1025.

[0160] On the other hand, when the UE determines in operation 1010 that the IE of the control message does not include the second control information, that is, when the UE adopts the conditional sending operation, it can return to the unconditional sending operation in operation 1020. That is, when an RRC connection reconfiguration message including an IE including the second control information is received, the conditional sending operation is initiated. When an RRC connection reconfiguration message including an IE including the second control information is received, the UE is released and returns to the unconditional sending operation. Thereafter, the UE proceeds to operation 1040. The IE may be SPS-ConfigUL or MAC-MainConfig.

[0161] In operation 1025, the UE determines whether the new uplink transmission is transmission via SPS transmission resources (or new transmission via the configured reverse grant) or transmission via an uplink grant allocated on a PDCCH addressed by the C-RNTI (or new transmission via dynamically allocated transmission resources). When the UE determines in operation 1025 that the new uplink transmission is transmission via SPS transmission resources, it adopts a first operation in operation 1030. When the UE determines in operation 1025 that the new uplink transmission is transmission via an uplink grant allocated on a PDCCH, it adopts a second operation in operation 1035.

[0162] The first operation may be a conditional sending operation or an unconditional sending operation. The second operation may be a conditional sending operation or an unconditional sending operation.

[0163] Operations 1025, 1030 and 1035 mean that conditional transmission operation can be selectively adopted according to the type of uplink transmission. For example, although the second control information has been configured, the conditional transmission operation is applied to the uplink transmission only when the uplink transmission is the transmission via SPS, and the unconditional transmission operation is applied to the uplink transmission only when the uplink transmission is the transmission of the transmission resources dynamically allocated on the PDCCH (when operation 1030 corresponds to conditional transmission and operation 1035 corresponds to unconditional transmission). Alternatively, the uplink transmission can: adopt unconditional transmission operation when the uplink transmission is the transmission via SPS; and adopt conditional transmission operation when the uplink transmission is the transmission of the transmission resources dynamically allocated on the PDCCH. Alternatively, no matter how the transmission type is (when operation 1030 corresponds to unconditional transmission and operation 1035 corresponds to conditional transmission), all transmissions can adopt conditional transmission operation.

[0164] When an uplink grant allowing new uplink transmission is available in operation 1040 , the UE applies an unconditional transmission operation to the uplink transmission in operation 1045 .

[0165] In the following description, rules of a conditional send operation and an unconditional send operation according to various embodiments of the present invention are explained.

[0166] [Conditional send operation]

[0167] When there is a MAC SDU available for transmission or there is a transmittable MAC control element (MAC CE) other than a BSR included for padding (padding BSR), the UE performs uplink transmission (or considering the presence of a valid uplink grant, the UE performs the following procedure for creating a MAC PDU).

[0168] When there is no MAC SDU available for transmission (i.e., data available for transmission does not exist in both the PDCP device and the RLC device) and there is no transmittable MAC CE other than the padding BSR, the UE does not perform uplink transmission (or considering that there is no valid uplink grant, the UE does not perform the following procedure for creating a MAC PDU).

[0169] Rule 2 of the conditional transmission operation may be modified in such a manner that: although MAC SDU available for transmission does not exist and transmittable MAC CEs other than padding BSR do not exist, when a serving cell to perform new transmission is scheduled in a TTI in which a new transmission together with transmission on PUCCH (such as HARQ ACK / NACK or CQI / PMI / RI) is instructed to be performed, the UE performs uplink transmission; and in a state where MAC SDU available for transmission does not exist and transmittable MAC CEs other than padding BSR do not exist, uplink transmission may be omitted only when simultaneous transmission together with transmission on PUCCH is not scheduled in the corresponding TTI. Because PUCCH transmission is performed using PUCCH transmission resources and part of PUSCH transmission resources, when the UE does not perform PUSCH transmission under the above conditions, the eNB may not be able to correctly receive PUCCH.

[0170] [Unconditional send operation]

[0171] When a MAC CE or MAC SDU available for transmission exists, the UE creates and transmits a general MAC PDU. When a MAC CE or MAC SDU available for transmission does not exist, the UE creates and transmits a padding MAC PDU configured with only padding and padding BSR.

[0172] In the following description, rules related to implicit release of SPS according to various embodiments of the present invention are explained.

[0173] According to various embodiments of the present invention, when conditional transmission and SPS have been configured, the UE does not adopt the implicit release of SPS. When SPS has been configured, the UE adopts the implicit release of SPS. As described above, because the information implicitReleaseAfter is not omitted in the SPS configuration information, implicitReleaseAfter is used or ignored according to the condition on whether conditional transmission is configured.

[0174] More specifically, when the UE receives an RRC control message including the first information, it determines whether the control message includes the second control information or a conditional sending operation has been adopted (i.e., when the UE receives the second control information). When the UE determines that the control message does not include the second control information or the conditional sending operation is not adopted, the UE considers the implicitReleaseAfter included in the first information (or uses an implicit release technique) to adopt an implicit release. On the other hand, when the UE determines that the control message includes the second control information or the conditional sending operation is adopted, the UE ignores the implicitReleaseAfter included in the first control information after the time when it receives the second control information, and it does not adopt an implicit release. That is, although the UE sends a zero MAC SDU MAC PDU multiple times (implicitReleaseAfter times) via the SPS sending resources, it does not release the SPS. A zero MAC SDU MAC PDU is referred to as a MAC PDU without a MAC SDU.

[0175] In the following description, padding MAC PDU and zero MAC SDU MAC PDU are explained.

[0176] A zero MAC SDU MAC PDU may include all MAC CEs listed below.

[0177] [Table 3]

[0178] index LCID value 10110 Shortened sidelink BSR 10111 Secondary Link BSR 11000 Dual Connectivity Power Headroom Report 11001 Extended Power Headroom Reporting 11010 Power Headroom Report 11011 C-RNTI 11100 Truncated BSR 11101 Short BSR 11110 Long BSR 11111 filling

[0179] On the other hand, the padding MAC PDU may include a padding MAC CE and a padding BSR. Depending on the size of the padding space, the padding BSR may be a truncated BSR, a short BSR, or a long BSR, as follows. The detailed BSR is shown below.

[0180] [Table 4]

[0181]

[0182]

[0183] <Example 2-2>

[0184] In various embodiments of the present invention, the UE selectively adopts an unconditional sending operation or a conditional sending operation according to an instruction of the ENB.

[0185] In various embodiments of the present invention, the UE selectively adopts an unconditional transmission operation or a conditional transmission operation according to the type of reverse transmission resources.

[0186] When the UE is able to use transmission resources to which the conditional transmission operation is applied, it determines whether a new data indicator (NDI) is switched based on the presence of data to be transmitted, and controls conditions as to whether it performs new transmission.

[0187] The present invention can selectively apply a conditional transmission operation to SPS transmission resources or normal transmission resources in consideration of conditions regarding whether SPS is configured.

[0188] Fig.11 is a flowchart describing operations between a UE and an ENB according to Embodiment 2-2.

[0189] In a mobile communication system including a UE 1105, an ENB 1110, and other nodes, in operation 1115, the UE establishes an RRC connection with the ENB. Establishing an RRC connection between the ENB and the UE means that the ENB and the UE configure a signaling radio bearer (SRB) SRB between them, thereby exchanging RRC control messages with each other. The RRC connection is established via a random access procedure in such a way that: the UE sends an RRC connection establishment request message to the ENB; the ENB sends an RRC connection establishment message to the UE; and the UE sends an RRC connection establishment completion message to the ENB.

[0190] After establishing the RRC connection, the ENB 1110 can instruct the UE 1105 to perform RRC connection reconfiguration in operation 1120. The ENB can provide the UE with first information and second information via an RRC connection reconfiguration message, instructing the UE to perform a conditional transmission operation.

[0191] The first information refers to information indicating the condition of whether the conditional transmission operation is applied to the dynamic authorization, and is formed by 1 bit. When the UE is notified with a 1-bit signal, the UE applies the conditional transmission operation to the dynamic authorization. When the UE is not notified with a 1-bit signal, the UE applies the unconditional transmission operation to the dynamic authorization. The dynamic authorization refers to the authorization allocated on the PDCCH and is used only once for the first transmission. In the following description, the first information is represented as SkipULTxDynamic.

[0192] The second information refers to information indicating the condition of whether the conditional sending operation is applied to the configured authorization, and is formed by 1 bit. When the UE is notified with a 1-bit signal, the UE applies the conditional sending operation to the configured authorization. When the UE is not notified with a 1-bit signal, the UE applies the unconditional sending operation to the configured authorization. The configured authorization refers to the authorization to which the SPS is applied, that is, once the authorization is allocated on the PDCCH, the authorization is used multiple times for the first transmission until it is released. In the following description, the second information is represented as SkipULTxSPS.

[0193] When the uplink transmission resources allocated for new transmission are available in operation 1125, the UE determines whether to perform uplink transmission in operation 1130. The uplink transmission resources allocated for new transmission may be transmission resources allocated via a PDCCH addressed by the C-RNTI of the UE or transmission resources for SPS, that is, a configured UL grant.

[0194] UE: considers conditions regarding whether the first information is configured (exists), conditions regarding whether the second information is configured (exists), types of available transmission resources, conditions regarding whether there is uplink data to be sent, characteristics of the uplink data to be sent, etc. to determine whether it performs transmission via the uplink transmission resources (or whether the NDI related to the uplink transmission resources is switched); and performs or does not perform uplink transmission based on the determination in operation 1130.

[0195] Fig.12 is a flow chart describing the operation of a UE.

[0196] In operation 1205, the UE receives an RRC connection reconfiguration control message, RRCConnectionReconfiguration. The UE reconfigures the RRC connection according to the received control message. For example, when the RRC connection reconfiguration message includes SPS configuration information, the UE configures SPS and performs SPS-related operations. The control message may include information related to the above-mentioned conditional transmission.

[0197] When the UE needs to perform uplink transmission in operation 1210, for example, when the UE is instructed to perform uplink transmission on the PDCCH, or when the time when the configured uplink grant is available is reached, the UE determines whether the relevant uplink grant is a configured grant or a dynamic grant received on the PDCCH in operation 1215. When the UE determines in operation 1215 that the relevant uplink grant is a dynamic grant received on the PDCCH, it proceeds to operation 1220. When the UE determines in operation 1215 that the relevant uplink grant is a configured grant, it proceeds to operation 1240.

[0198] In operation 1220, the UE determines whether SkipTxDynamic is configured. When the UE determines that SkipTxDynamic is configured in operation 1220, it proceeds to operation 1225. When the UE determines that SkipTxDynamic is not configured in operation 1220, it proceeds to operation 1265.

[0199] In operation 1225 , the UE determines whether it satisfies the following conditions. When the UE satisfies the following conditions in operation 1225 , it proceeds to operation 1230 . When the UE does not satisfy the following conditions in operation 1225 , it proceeds to operation 1235 .

[0200] <Conditions>

[0201] There is data available for transmission and the NDI of the relevant HARQ process is different from the previous value (or is switched).

[0202] NDI is managed in each HARQ process and controls HARQ operation. The HARQ device determines whether NDI is changed and distinguishes new transmission and retransmission based on the determination.

[0203] The UE triggers HARQ retransmission in operation 1230. The triggered HARQ retransmission is connected to the HARQ retransmission at timing.

[0204] The UE triggers the first HARQ transmission in operation 1235. The triggered first HARQ transmission may be connected to the first HARQ transmission at timing.

[0205] The UE determines whether SkipTxSPS is configured in operation 1240. When the UE determines that SkipTxSPS is configured in operation 1240, it proceeds to operation 1245. When the UE determines that SkipTxSPS is not configured in operation 1240, it proceeds to operation 1265.

[0206] In operation 1245, the UE determines whether it satisfies the following conditions. When the UE satisfies the following conditions in operation 1245, it proceeds to operation 1250. When the UE does not satisfy the following conditions in operation 1245, it proceeds to operation 1260.

[0207] <Conditions>

[0208] There is data available to send

[0209] The UE considers that the NDI of the corresponding HARQ process is switched in operation 1250 and triggers the first transmission in operation 1255. That is, when data available for transmission exists, the UE does not consider the actual NDI for the configured transmission resources, but considers that the NDI has been switched and triggers new transmission.

[0210] The UE does not consider that the NDI has been switched and does not trigger new transmission in operation 1260. That is, in a state where SkipTxSPS has been configured, even though there is a configured uplink grant, when data available for transmission does not exist, the UE does not consider that the NDI has been switched and does not trigger new transmission.

[0211] In operation 1265, the UE operates in the same manner as in the prior art. That is, the UE performs reverse transmission according to the indicated reverse grant or the configured reverse grant regardless of the presence of data available for transmission.

[0212] In an embodiment of the present invention, when data available for transmission exists, it means that data available for transmission exists in a higher layer, or a MAC CE other than a truncated BSR or a padded BSR exists. The higher layer data available for transmission may refer to PDCP SDU, PDCP PDU, RLC SDU, and RLC PDU.

[0213] <Example 2-3>

[0214] With the evolution of mobile communication systems, minimization of uplink delay has become an important issue. The present invention provides a shared SPS scheme for reducing uplink delay.

[0215] Most of the uplink delay is caused in the process of UE requesting the allocation of transmission resources and the allocation of transmission resources. In the state where the UE is continuously allocated SPS transmission resources, when data is created, the UE can perform fast transmission of data. However, when the SPS transmission resources are specifically allocated to all UE devices, the transmission resources are over-consumed. In order to solve this problem, various embodiments of the present invention introduce a shared SPS scheme that allocates the same SPS transmission resources to multiple UE devices. A UE device configured with a shared SPS only performs data transmission when it has data to be transmitted. A UE device configured with a shared SPS monitors the PDCCH and applies different UE identifiers to uplink scrambling so that the ENB can identify the uplink data from the UE device separately. Because the shared SPS scheme only uses a small part of the given resources, it is preferred that the scheme is applied to a small cell with abundant transmission resources. Therefore, unlike the general SPS scheme, the shared SPS scheme is used for the service cell specified by the ENB.

[0216] Fig.13 is a flowchart describing operations between a UE and an ENB according to Embodiment 2-3.

[0217] In a mobile communication system including UE 1305, ENB 1310 and other nodes, in operation 1315, the UE establishes an RRC connection with the ENB. Establishing an RRC connection between the UE and the ENB means that the ENB and the UE configure a signaling radio bearer (SRB) between them, thereby exchanging RRC control messages with each other. The RRC connection is established via a random access procedure in such a way that: the UE sends an RRC connection establishment request message to the ENB; the ENB sends an RRC connection establishment message to the UE; and the UE sends an RRC connection establishment completion message to the ENB.

[0218] After establishing the RRC connection, if necessary, in operation 1520, the ENB 1310 can send a UECapabilityEnquiry control message indicating that the UE 1305 reports the UE capability to the UE 1305. The control message includes a field indicating a radio access technology (RAT) type of the capability about the RAT from among the capabilities of the UE. When the ENB is reported about the capability of EUTRA, the ENB sets the RAT type to EUTRA.

[0219] When receiving the UECapabilityEnquiry control message in which the RAT type is set to EUTRA, the UE 1305 transmits a UECapabilityInformation control message including the UE's capability information on EUTRA to the ENB 1310 in operation 1325 .

[0220] The control message includes UE-EUTRA-Capability. UE-EUTRA-Capability includes a list of names of features supported by the UE, the category of the UE (ue-Category), the combination of frequency bands supported by the UE (supportedBandCombination), etc. The UE supports the shared SPS function. When the UE has completed the interoperability test of the shared SPS function, it can include an IE indicating that it can support the shared SPS function in the control message.

[0221] When the ENB 1310 determines that delay reduction needs to be applied to the UE 1305, it can instruct the UE 1305 to perform RRC connection reconfiguration in operation 1330. The ENB can send the shared SPS configuration information to the UE via an RRC connection reconfiguration message. The shared SPS configuration information is formed by SPS-Config information and SPS-Config-ext.

[0222] The structure of SPS-Config may be the same as the SPS configuration information in part 2-1 of the above embodiment.

[0223] The structure of SPS-Config-ext is as follows.

[0224]

[0225] In summary, SPS-Config can include the following IEs:

[0226] First SPS C-RNTI (semiPersistSchedC-RNTI)

[0227] First interval (semiPersistSchedIntervalUL)

[0228] Automatic release parameters (semiPersistSchedC-RNTI)

[0229] For example, SPS-Config-ext may include the following IEs:

[0230] Shared SPS indicator (SPS-Config-ext may be used as a shared SPS indicator or additional indicators may be used)

[0231] Second SPS C-RNTI (semiPersistSchedC-RNTI2)

[0232] Second interval (semiPersistSchedIntervalUL2)

[0233] Logical Channel List (logicalChannelIdList): A list of names of logical channels that can use the shared SPS

[0234] Serving cell id (SharedSPSenabledCell): The identifier of the serving cell that will activate / adopt shared SPS

[0235] In operation 1335, the UE 1305 monitors whether the SPS function is activated. The UE 1305 monitors whether the general SPS and the shared SPS are activated, respectively.

[0236] Setting the general SPS function for the UE device means that: at the corresponding timing, only SPS-config is set to the UE, but SPS-config-ext is not set to the UE. This corresponds to the following situations: the UE has received an rrcConnectionReconfiguration message including a valid SPS-config from the ENB; the UE has not released the received SPS-config; the UE has not received SPS-Config-ext; and the UE has received SPS-Config-ext but has released SPS-Config-ext. For example, when a UE that is not set with SPS receives an rrcConnectionReconfiguration control message that includes only SPS-config but not SPS-Config-ext, it is set with general SPS.

[0237] Setting the shared SPS function to the UE device means that: SPS-config and SPS-config-ext are set to the UE at the corresponding timing. This corresponds to the following situation: the UE has received an rrcConnectionReconfiguration message including a valid SPS-config and a valid SPS-Config-ext from the ENB; and the UE has not released the received SPS-config and the received SPS-Config-ext. For example, when a UE that is not set with SPS receives an rrcConnectionReconfiguration control message including SPS-config and SPS-Config-ext, it is set with a shared SPS.

[0238] A UE equipped with a general SPS monitors the PDCCH of a PCell or PSCell (hereinafter collectively referred to as SpCell) and determines whether SPS is activated. When the UE receives an uplink grant on the PDCCH of the SpCell via the first SPS C-RNTI, it checks the new data indicator (NDI) of the uplink grant. When the NDI is '0' and the information about the PDCCH is not information for specifying release, the UE stores the uplink grant and the associated HARQ information as the configured uplink grant and initiates SPS operation.

[0239] When a UE configured with shared SPS receives an uplink grant via the SPSC-RNTI for monitoring via the PDCCH of the serving cell designated as SharedSPSenabledCell or via the PDCCH of the scheduling cell of the serving cell (referring to the cell CrossCarrierSchedulingConfig providing scheduling information about the serving cell) in a state of adopting cross-carrier scheduling, it checks the NDI of the uplink grant. When the NDI is '0' and the information on the PDCCH is not information specifying release, the UE stores the uplink grant and the associated HARQ information as the configured uplink grant and initiates shared SPS operation.

[0240] The SPS C-RNTI used for monitoring may be the first SPS C-RNTI or the second SPS C-RNTI.

[0241] In the general SPS operation, the SPS C-RNTI used to monitor the SPS activation signal is the same as the SPS C-RNTI used for scrambling on the PUSCH. That is, the UE monitors the PDCCH by using one SPS C-RNTI as the first SPS C-RNTI and scrambles the uplink data.

[0242] In the shared SPS operation, the SPS C-RNTI for monitoring PDCCH and the SPS C-RNTI for scrambling uplink data are separated from each other. For example, PDCCH is monitored by the first SPS-CRNTI, and PUSCH is scrambled by the second SPS C-RNTI. Alternatively, PDCCH is monitored by the second SPS-CRNTI, and PUSCH is scrambled by the first SPS C-RNTI. These operations are performed separately, because the SPS C-RNTI for monitoring is an identifier commonly applied to multiple UE devices, so when the uplink data is scrambled with the SPS C-RNTI for monitoring, the ENB cannot identify the UE that sends the uplink data. Therefore, the SPS C-RNTI for uplink scrambling adopts the UE-specific SPS C-RNTI. That is, for multiple UE devices in the shared SPS, the ENB assigns the same value to the SPS C-RNTI for monitoring. On the other hand, the ENB assigns unique values ​​to the SPS C-RNTI for scrambling for the UE device, respectively.

[0243] Scrambling of PUSCH by using SPS C-RNTI is defined in TS 36.212 and TS 36.213.

[0244] When the UE receives an uplink grant indicating initiation of a common SPS operation or a shared SPS operation in operation 1340 , it initiates the common SPS operation or the shared SPS operation in operation 1345 .

[0245] In the following description, general SPS operations are explained.

[0246] The UE performs uplink transmission using SPS resources based on the subframe in which the SPS operation is initiated, with a period of semiPersistSchedIntervalUL in the SpCell (including a period in the SPS-config). For example, the UE determines that the Nth grant has been created in the subframe of the SpCell, and performs uplink transmission by applying the corresponding grant to the subframe.

[0247] Although the UE has no data to transmit at corresponding timing when transmitting a MAC PDU via an SPS resource, it creates and transmits a padding MAC PDU including a BSR MAC CE and a padding MAC CE. The UE may apply the first SPS C-RNTI to a scrambling operation of uplink transmission.

[0248] The UE releases the configured uplink grant when only zero MAC SDU MAC PDUs are sent with implicitReleaseAfter.

[0249] In the following description, a shared SPS operation is explained.

[0250] The UE performs uplink transmission using shared SPS resources with a period of semiPersistSchedIntervalUL2 in SharedSPSenabledCell (including a period in SPS-config-ext) based on the subframe in which the SPS operation is initiated. For example, the UE determines that the Nth grant has been created in the subframe of the SpCell, and performs uplink transmission by applying the corresponding grant to the subframe.

[0251] When the UE does not have 'data available for transmission via the shared SPS transmission resources' at the corresponding timing of transmitting the MAC PDU via the SPS resources, it does not perform uplink transmission. Although only a zero MAC SDU MAC PDU is transmitted after implicitReleaseAfter, the UE does not release the configured uplink grant. A zero MAC SDU MAC PDU refers to a MAC PDU including only a MAC CE but not a MAC SDU including higher layer data. The UE performs scrambling for uplink transmission by adopting an SPS C-RNTI different from the SPS C-RNTI used to monitor the PDCCH. The SPS C-RNTI applied for scrambling may be the C-RNTI of the UE. That is, the identifier may be formed according to various combinations in Table 5 below.

[0252] [Table 5]

[0253]

[0254] In Table 5, the last row is the case where SPS C-RNTI 2 is not allocated in SPS-config-ext. In this case, the UE uses its C-RNTI (i.e., its UE-specific identifier) ​​to scramble the shared SPS uplink transmission.

[0255] As described above, the UE is able to send only the data of the logical channel logicalChannelIdList via the shared SPS transmission resources. Although the UE has data of other logical channels other than the data of the logicalChannelIdList (e.g., RRC messages, etc.), it does not consider the data as 'data available for transmission via the shared SPS transmission resources', but only considers the data of the logical channels of the logicalChannelIdList as 'data available for transmission via the shared SPS transmission resources'.

[0256] When the UE 1305 receives the uplink grant indicating the SPS release in operation 1350, it terminates the SPS operation and releases the configured uplink grant or the configured shared uplink grant.

[0257] Fig.14 is a flowchart describing the operation of the UE according to Embodiment 2-3.

[0258] The UE does not receive a valid SPS-config; or although the UE receives a valid SPS-config, it has released the SPS-config. In operation 1405, the UE receives a control message RRCConnectionReconfiguration.

[0259] The UE determines whether the control message includes SPS-config and SPS-config-ext in operation 1410 . When the UE determines that the control message includes both SPS-config and SPS-config-ext in operation 1410 , it performs an operation related to sharing the SPS in operation 1415 .

[0260] When the UE determines that the control message includes only SPS-config in operation 1410 , it performs an operation related to general SPS in operation 1420 .

[0261] Table 6 below describes operations related to a shared SPS and operations related to a general SPS.

[0262] [Table 6]

[0263]

[0264] Table 7 below shows operations according to another embodiment.

[0265] [Table 7]

[0266]

[0267]

[0268] The common search space and the dedicated search space comply with TS 36.211, 36.212 and 36.213.

[0269] Fig.15 is a block diagram showing the configuration of a UE according to Embodiment 2 of the present invention.

[0270] refer to Fig.15 , the UE includes a radio frequency (RF) processing unit 1510, a baseband processing unit 1520, a storage unit 1530 and a controller 1540.

[0271] The RF processing unit 1510 performs functions related to the transmission / reception of signals via a wireless channel, such as conversion of frequency bands, amplification, etc. The RF processing unit 1510 up-converts the baseband signal output from the baseband processing unit 1520 into an RF band signal and transmits the RF signal via an antenna. The RF processing unit 1510 down-converts the RF band signal received via the antenna into a baseband signal. The RF processing unit 1510 can include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. Although in Fig.15The embodiment is shown so that the UE includes only one antenna, but it should be understood that the UE can be implemented to include multiple antennas. The RF processing unit 1510 can also be implemented to include multiple RF chains. The RF processing unit 1510 is capable of performing beamforming operations. In order to perform the beamforming function, the RF processing unit 1510 is capable of adjusting the phase and amplitude of individual signals sent / received via multiple antennas or antenna elements. The RF processing unit 1510 is capable of performing MIMO and receiving multiple layers in MIMO.

[0272] The baseband processing unit 1520 performs conversion between baseband signals and bit streams according to the physical layer specifications (rules) of the system. For example, in data transmission, the baseband processing unit 1520 encodes and modulates the transmission bit stream to create complex symbols. In data reception, the baseband processing unit 1520 demodulates and decodes the baseband signal output from the RF processing unit 1510 to restore the received bit stream. For example, in data transmission according to orthogonal frequency division multiplexing (OFDM), the baseband processing unit 1520 encodes and modulates the transmission bit stream to create complex symbols, maps the complex symbols to subcarriers, and configures OFDM symbols through inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. In data reception, the baseband processing unit 1520 separates the baseband signal output from the RF processing unit 1510 into OFDM symbol units, restores the signal mapped to the subcarrier through a fast Fourier transform (FFT) operation, and then restores the received bit stream through demodulation and decoding operations.

[0273] The baseband processing unit 1520 and the RF processing unit 1510 perform the transmission and reception of signals as described above. Therefore, the baseband processing unit 1520 and the RF processing unit 1510 may also be referred to as a transmitter, a receiver, a transceiver, a communication unit, etc. In addition, the baseband processing unit 1520 and / or the RF processing unit 1510 may include a plurality of communication modules to support wireless access technologies that are different from each other. Alternatively, the baseband processing unit 1520 and / or the RF processing unit 1510 may include different communication modules to process signals of different frequency bands. Examples of wireless access technologies are: wireless LAN (e.g., IEEE 802.11), cellular networks (e.g., LTE), etc. Examples of different frequency bands are: ultra-high frequency (SHF) (e.g., 2.5 GHz band, 5 GHz band, etc.), millimeter wave (mmW) (e.g., 60 GHz band), etc.

[0274] The storage unit 1530 stores default programs, applications, settings, data, etc. for operating the UE. In particular, the storage unit 1530 can store information related to a second access node that performs wireless communication using a second radio access technology. The storage unit 1530 provides stored data according to a request of the controller 1540.

[0275] The controller 1540 controls all operations of the UE. For example, the controller 1540 controls the baseband processing unit 1520 and the RF processing unit 1510 to perform signal transmission / reception. The controller 1540 controls the storage unit 1540 to store / read data therein / from it. To this end, the controller 1540 can include at least one processor. For example, the controller 1540 can include a communication processor (CP) for controlling communication and an application processor (AP) for controlling a higher layer such as an application. According to various embodiments of the present invention, the controller 1540 can control the UE to perform the above reference Figures 9 to 14 Describes the functions and procedures.

[0276] Fig.16 is a block diagram showing an ENB included in a wireless communication system according to Embodiment 2 of the present invention.

[0277] like Fig.16 As shown, the ENB includes an RF processing unit 1610 , a baseband processing unit 1620 , a backhaul communication unit 1630 , a storage unit 1640 , and a controller 1650 .

[0278] The RF processing unit 1610 performs functions related to the transmission / reception of signals via a wireless channel, such as conversion of frequency bands, amplification, etc. The RF processing unit 1610 up-converts the baseband signal output from the baseband processing unit 1620 into an RF band signal and transmits the RF signal via an antenna. The RF processing unit 1610 down-converts the RF band signal received via the antenna into a baseband signal. The RF processing unit 1610 can include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although in Fig.16 The embodiment shown in the figure makes the RF processing unit include only one antenna, but it should be understood that the RF processing unit 1610 can be modified to include multiple antennas. The RF processing unit 1610 can also be implemented to include multiple RF chains. The RF processing unit 1610 is capable of performing beamforming operations. In order to perform beamforming functions, the RF processing unit 1610 is capable of adjusting the phase and amplitude of individual signals sent / received via multiple antennas or antenna elements. The RF processing unit 1610 is capable of sending one or more layers, thereby performing downlink MIMO functions.

[0279] The baseband processing unit 1620 performs conversion between a baseband signal and a bit stream according to the physical layer specification (rule) of the first wireless access technology. For example, in data transmission, the baseband processing unit 1620 encodes and modulates the transmission bit stream to create a complex symbol. In data reception, the baseband processing unit 1620 demodulates and decodes the baseband signal output from the RF processing unit 1610 to restore the received bit stream. For example, in data transmission according to orthogonal frequency division multiplexing (OFDM), the baseband processing unit 1620 encodes and modulates the transmission bit stream to create a complex symbol, maps the complex symbol to a subcarrier, and configures the OFDM symbol by an inverse fast Fourier transform (IFFT) operation and a cyclic prefix (CP) insertion. In data reception, the baseband processing unit 1620 separates the baseband signal output from the RF processing unit 1610 into OFDM symbol units, restores the signal mapped to the subcarrier by a fast Fourier transform (FFT) operation, and then restores the received bit stream by a demodulation and decoding operation. The baseband processing unit 1620 and the RF processing unit 1610 perform transmission and reception of signals as described above. Therefore, the baseband processing unit 1620 and the RF processing unit 1610 may also be referred to as a transmitter, a receiver, a transceiver, a communication unit, a wireless communication unit, etc.

[0280] The backhaul communication unit 1630 provides an interface to communicate with other nodes in the network. That is, the backhaul communication unit 1630: converts the bitstream into a physical signal to be sent to other nodes of the primary ENB (e.g., secondary ENB, core network, etc.); and converts the physical signal from other nodes into a bitstream.

[0281] The storage unit 1640 stores default programs, applications, settings, data, etc. for operating the master ENB. In particular, the storage unit 1640 can store information about a bearer assigned to a connected UE, a measurement result reported from a connected UE, etc. The storage unit 1640 can provide a dual connection function to the UE or store reference information to determine whether the ENB terminates the dual connection operation. The storage unit 1640 provides the stored data according to a request of the controller 1650.

[0282] The controller 1650 controls all operations of the master ENB. For example, the controller 1650 controls the baseband processing unit 1620, the RF processing unit 1610, and the backhaul communication unit 1630 to perform signal transmission / reception. The controller 1650 controls the storage unit 1640 to store / read data therein / from it. To this end, the controller 1650 can include at least one processor. The controller 1650 can include a dual connection controller 1652 that provides a dual connection function to the UE. For example, the controller 1650 can control the master ENB to perform the above reference Fig. 9 , Fig.11 and Fig.13 The functions and programs described in the claims or the specification can be implemented by hardware, software, and a combination thereof. When the methods are implemented by software, a computer-readable storage medium storing one or more programs (software modules) is provided. One or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. One or more programs include instructions for enabling an electronic device to perform the methods according to the embodiments described in the claims or the specification. These programs (software modules and software) are stored in: random access memory (Random Access Memory, RAM), flash memory, non-volatile memory, read-only memory (ROM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read Only Memory, EEPROM), magnetic disk storage device, compact disc ROM (Compact Disc-ROM, CD-ROM), digital versatile disc (Digital Versatile Disc, DVD) or other types of optical storage devices, magnetic tapes, etc., or a combination thereof. In addition, two or more of the same type of memory form a storage block. In addition, the program can also be stored in an attachable storage device that can be accessed through a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), a storage area network (SAN) or a combination thereof. The storage device can be connected to the device according to the present invention via an external port. In addition, a separate storage device of a communication network can be connected to the device according to the present invention.

[0283] The terms used in the various embodiments of the present invention are for the purpose of describing the particular embodiments only and are not intended to limit the present disclosure.Singular forms are intended to include plural forms unless the context clearly indicates otherwise.

[0284] Although embodiments of the present invention have been described in detail above, it should be understood that many various changes and modifications to the basic inventive concept described herein that may be apparent to those skilled in the art will still fall within the spirit and scope of embodiments of the present invention as defined by the appended claims.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving a radio resource control RRC message including a medium access control MAC configuration of the terminal from the base station, the RRC message being used for reconfiguration of the RRC connection; identifying information indicating whether the terminal skips uplink transmission, the information being included in the MAC configuration; receiving an uplink grant from the base station on a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI); and Based on the information, it is identified whether to skip generation of a MAC protocol data unit (PDU) associated with the uplink grant.

2. The method according to claim 1, wherein: The generation of MAC PDU is skipped if the following conditions are met: The MAC service data unit SDU for the MAC PDU does not exist; and The MAC Control Element CE for a MAC PDU only includes a buffer status report BSR of a predetermined type, The predetermined type of BSR includes a padding BSR.

3. The method according to claim 2, further comprising: If generation of the MAC PDU is not skipped, generating a MAC PDU associated with the uplink grant; and The generated MAC PDU is sent to the base station on uplink resources scheduled based on the uplink grant.

4. A terminal in a wireless communication system, the terminal comprising: a transceiver configured to transmit or receive signals; and The controller is configured as: receiving a radio resource control RRC message including a medium access control MAC configuration of the terminal from the base station, the RRC message being used for reconfiguration of the RRC connection, identifying information indicating whether the terminal skips uplink transmission, the information being included in the MAC configuration, receiving an uplink grant from the base station on a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI), and Based on the information, it is identified whether to skip generation of a MAC protocol data unit (PDU) associated with the uplink grant.

5. The terminal according to claim 4, wherein: The generation of MAC PDU is skipped if the following conditions are met: The MAC service data unit SDU for the MAC PDU does not exist; and The MAC Control Element CE for a MAC PDU only includes a buffer status report BSR of a predetermined type, The predetermined type of BSR includes a padding BSR. The terminal according to claim 5, wherein: The controller is also configured to: generating a MAC PDU associated with the uplink grant in case generation of the MAC PDU is not skipped, and The generated MAC PDU is sent to the base station on uplink resources scheduled based on the uplink grant.

7. A method performed by a system including a terminal and a base station, the method comprising: The base station sends a radio resource control RRC message including a media access control MAC configuration of the terminal to the terminal, where the RRC message is used for reconfiguration of an RRC connection; and sending, by the base station, an uplink grant to the terminal on a physical downlink control channel PDCCH addressed to a cell radio network temporary identifier C-RNTI, Whether to skip generation of a MAC protocol data unit (PDU) associated with the uplink grant is identified by the terminal based on information included in the MAC configuration, wherein the information indicates whether the terminal skips uplink transmission.

8. The method according to claim 7, wherein: The terminal skips the generation of MAC PDU if the following conditions are met: The MAC service data unit SDU for the MAC PDU does not exist; and The MAC Control Element CE for a MAC PDU only includes a buffer status report BSR of a predetermined type, The predetermined type of BSR includes a padding BSR.

9. The method according to claim 8, further comprising: generating, by the terminal, a MAC PDU associated with the uplink grant, if generation of the MAC PDU is not skipped, and The terminal sends the generated MAC PDU to the base station on the uplink resources scheduled based on the uplink grant.

10. A system comprising: terminal; and Base station, The base station is configured as: sending a radio resource control (RRC) message including a medium access control (MAC) configuration of the terminal to the terminal, the RRC message being used for reconfiguration of an RRC connection, and sending an uplink grant to the terminal on a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI), and Whether to skip generation of a MAC protocol data unit (PDU) associated with the uplink grant is identified by the terminal based on information included in the MAC configuration, wherein the information indicates whether the terminal skips uplink transmission.

11. The system according to claim 10, wherein: The generation of MAC PDU is skipped by the terminal under the following conditions: The MAC service data unit SDU for the MAC PDU does not exist; and The MAC Control Element CE for a MAC PDU only includes a buffer status report BSR of a predetermined type, The predetermined type of BSR includes a padding BSR.

12. The system according to claim 11, wherein: The terminal is configured as follows: generating a MAC PDU associated with the uplink grant in case generation of the MAC PDU is not skipped, and The generated MAC PDU is sent to the base station on uplink resources scheduled based on the uplink grant.

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