Method and apparatus for reducing power consumption of fixed terminals in wireless communication system

Abstract

The present disclosure relates to a communication technique and a system for integrating a 5G (5th generation) or pre-5G communication system with IoT technology to support higher data transmission rates than those of 4G (4th generation) communication systems such as LTE (Long Term Evolution). The present disclosure may be applied to intelligent services (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. According to various embodiments of the present invention, a method and apparatus for reducing power consumption of a fixed terminal may be provided.

Description

Technology Field

[0001] The present invention relates to a method for reducing power consumption of a non-mobile fixed terminal among 'NR-light (NR-lite)' terminals that reduce cost and complexity in a wireless communication system, more specifically in 3GPP 5G NR (New Radio). Background Technology

[0002] Efforts are being made to develop improved 5G (5th generation) communication systems or pre-5G communication systems to meet the increasing demand for wireless data traffic following the commercialization of 4G (4th generation) communication systems. For this reason, 5G communication systems or pre-5G communication systems are referred to as Beyond 4G Network communication systems or Post-LTE systems.

[0003] To achieve high data transmission rates, 5G communication systems are being considered for implementation in the mmWave band (e.g., the 60 GHz band). To mitigate path loss and increase the transmission distance of radio waves in the mmWave band, beamforming, massive MIMO, full Dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large-scale antenna technologies are being discussed for 5G communication systems.

[0004] In addition, to improve the network of the system, technologies such as advanced small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation are being developed in 5G communication systems.

[0005] In addition, advanced coding modulation (ACM) methods such as FQAM (Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation) and SWSC (Sliding Window Superposition Coding), as well as advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (Non Orthogonal Multiple Access), and SCMA (Sparse Code Multiple Access) are being developed in 5G systems.

[0006] 5G systems are considering support for a wider variety of services compared to existing 4G systems. For example, the most representative services may include enhanced mobile broadband (eMBB), ultra-reliable and low-latency communication (URLLC), massive machine-type communication (mMTC), and evolved multimedia broadcast / multicast service (eMBMS). Furthermore, a system providing the aforementioned URLLC service may be referred to as a URLLC system, and a system providing eMBB service may be referred to as an eMBB system. Additionally, the terms "service" and "system" may be used interchangeably.

[0007] Among these, URLLC services are being newly considered in 5G systems, unlike existing 4G systems, and require the satisfaction of ultra-high reliability (e.g., packet error rate of about 10⁻⁵) and low latency (e.g., about 0.5 msec) conditions compared to other services. To satisfy these strict requirements, URLLC services may require the application of a transmission time interval (TTI) shorter than that of eMBB services, and various operational methods utilizing this are being considered.

[0008] Meanwhile, the Internet is evolving from a human-centered network where humans generate and consume information into an IoT (Internet of Things) network where distributed components, such as objects, exchange and process information. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connections with cloud servers, is also emerging. To implement IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required; recently, technologies such as sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) are being researched for connecting objects.

[0009] In an IoT environment, intelligent IT (Internet Technology) services that create new value for human life by collecting and analyzing data generated from connected objects can be provided. Through the convergence and integration of existing IT (Information Technology) and various industries, IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0010] Accordingly, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, Machine to Machine (M2M), and Machine Type Communication (MTC) are being implemented using 5G communication techniques such as beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology, as previously described, can also be considered an example of the convergence of 5G and IoT technologies. The problem to be solved

[0011] The present invention aims to provide a method for reducing power consumption and reducing the paging area for non-mobile fixed terminals among NR light terminals.

[0012] The technical problems to be solved by the present invention are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0013] The present invention, for solving the above-mentioned problems, is characterized in that a method for processing a control signal in a wireless communication system comprises: a step of receiving a first control signal transmitted from a base station; a step of processing the received first control signal; and a step of transmitting a second control signal generated based on the processing to the base station. Effects of the invention

[0014] According to one embodiment of the present invention, power consumption for a fixed terminal is reduced, and when paging to a terminal in sleep mode, paging is transmitted to specific base stations rather than an unspecified number of base stations, thereby reducing the waste of wireless resources caused by paging transmission.

[0015] The effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below. Brief explanation of the drawing

[0016] FIG. 1a is a drawing illustrating the structure of an NR system according to one embodiment of the present invention. FIG. 1b is a diagram showing a wireless protocol structure in an LTE and NR system according to one embodiment of the present invention. FIG. 1c is an example diagram of the downlink and uplink channel frame structure when performing beam-based communication in an NR system according to one embodiment of the present invention. FIG. 1d is an example diagram illustrating a procedure for a non-mobile NR light terminal to perform a connection to a network according to one embodiment of the present invention. FIG. 1e is an example diagram of the procedure sequence of a terminal and a base station when a non-mobile NR light terminal performs a connection to a network according to one embodiment of the present invention. FIG. 1f illustrates the block configuration of a terminal in a wireless communication system according to one embodiment of the present invention. Specific details for implementing the invention

[0017] The operating principle of the present invention will be described in detail below with reference to the attached drawings. In describing the present invention below, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. Terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc., are provided as examples for the convenience of explanation. Accordingly, the present invention is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

[0018] For the convenience of the following explanation, the present invention uses terms and names defined in the LTE and NR specifications, which are the most recent standards defined by the 3GPP (The 3rd Generation Partnership Project) among currently existing communication standards. However, the present invention is not limited by the above terms and names and can be applied in the same way to systems conforming to other standards. In particular, the present invention can be applied to 3GPP NR (5th generation mobile communication standard).

[0019] FIG. 1a is a drawing illustrating the structure of an NR system according to one embodiment of the present invention.

[0020] Referring to FIG. 1a, the wireless communication system may be composed of several base stations (1a-05)(1a-10)(1a-15)(1a-20), an access and mobility management function (AMF) (1a-20), and a user plane function (UPF) (1a-30). A user terminal (user equipment, hereinafter referred to as UE or terminal, terminal) (1a-35) connects to an external network through the base stations (1a-05)(1a-10)(1a-15)(1a-20) and the UPF (1a-30).

[0021] The above base stations (1a-05)(1a-10)(1a-15)(1a-20) can provide wireless access to terminals connected to the network as connection nodes of a cellular network. That is, the above base stations (1a-05)(1a-10)(1a-15)(1a-20) can support a connection between the terminals and the core network (CN, core network; in particular, the CN of NR is referred to as 5GC) by collecting status information such as the buffer status, available transmission power status, and channel status of the terminals to service the traffic of the users and scheduling. Meanwhile, communication can be configured by dividing the user plane (UP), which is related to the transmission of actual user data, and the control plane (CP), which is related to connection management. In this drawing, gNB (1a-05) (1a-20) uses the UP and CP technologies defined in NR technology, and ng-eNB (1a-10) (1a-15), although connected to 5GC, uses the UP and CP technologies defined in LTE technology.

[0022] The above AMF / SMF (1a-25) is a device responsible for various control functions as well as mobility management functions for terminals and is connected to multiple base stations, and the UPF (1a-30) is a type of gateway device that provides data transmission.

[0023] FIG. 1b is a diagram showing a wireless protocol structure in an LTE and NR system according to one embodiment of the present invention.

[0024] Referring to FIG. 1b, the wireless protocols of LTE and NR systems consist of a packet data convergence protocol (PDCP) (1b-05)(1b-40), a radio link control (RLC) (1b-10)(1b-35), and a medium access control (MAC) (1b-15)(1b-30) at the terminal and the eNB / gNB, respectively. The packet data convergence protocol (PDCP) (1b-05)(1b-40) is responsible for operations such as IP header compression / decompression, and the radio link control (hereinafter referred to as RLC) (1b-10)(1b-35) reconstructs the PDCP packet data unit (PDU) into an appropriate size. The MAC (1b-15)(1b-30) is connected to multiple RLC layer devices configured in a terminal and performs the operation of multiplexing RLC PDUs into MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The physical layer (1b-20)(1b-25) performs the operation of channel coding and modulating upper layer data, converting it into OFDM (orthogonal frequency division multiplexing) symbols and transmitting them over a wireless channel, or demodulating OFDM symbols received through the wireless channel and channel decoding them to transmit them to the upper layer. In addition, the physical layer also uses HARQ (hybrid ARQ) for additional error correction, and the receiving end transmits a 1-bit indicating whether the packet transmitted by the transmitting end has been received. This is called HARQ ACK / NACK information.In the case of LTE, downlink HARQ ACK / NACK information for uplink data transmission is transmitted via the physical channel of the PHICH (physical hybrid-ARQ indicator channel), whereas in the case of NR, it is possible to determine whether retransmission is required or if a new transmission can be performed through the scheduling information of the terminal in the PDCCH (physical dedicated control channel), which is the channel where downlink / uplink resource allocation is transmitted. This is because asynchronous HARQ is applied in NR. Uplink HARQ ACK / NACK information for downlink data transmission can be transmitted via the physical channel of the PUCCH (physical uplink control channel) or PUSCH (physical uplink shared channel). The above PUCCH is generally transmitted in the uplink of the PCell described later, but if the terminal supports it, the base station may additionally transmit it to the SCell described later to the terminal, which is referred to as the PUCCH SCell.

[0025] Although not shown in this drawing, an RRC (radio resource control) layer exists above the PDCP layer of the terminal and the base station, respectively, and the RRC layer can exchange connection and measurement-related setting control messages for radio resource control.

[0026] Meanwhile, the above PHY layer can be composed of one or more frequencies / carriers, and the technology of simultaneously setting and using multiple frequencies at a single base station is called Carrier Aggregation (hereinafter referred to as CA). CA technology allows for a significant increase in transmission capacity by the number of secondary carriers by using one or more secondary carriers in addition to the primary carrier, whereas previously only one carrier was used for communication between a terminal (or user equipment, UE, terminal) and a base station (eNB in ​​LTE or gNB in ​​NR). Meanwhile, in LTE, a cell within a base station that uses the primary carrier is called a PCell (primary cell), and a secondary carrier is called a SCell (secondary cell). The technology that extends the above CA function to two base stations is called Dual Connectivity (hereinafter referred to as DC). In the above DC technology, a terminal connects to and uses a master base station (master E-UTRAN node B, hereinafter referred to as MeNB) and a secondary base station (secondary E-UTRAN node B, hereinafter referred to as SeNB) simultaneously. Cells belonging to the master base station are called the master cell group (hereinafter referred to as MCG), and cells belonging to the secondary base station are called the secondary cell group (hereinafter referred to as SCG). Each of the above cell groups has a representative cell. The representative cell of the master cell group is called the primary cell (hereinafter referred to as PCell), and the representative cell of the secondary cell group is called the primary secondary cell (hereinafter referred to as PSCell). When using the above NR, the terminal can use LTE technology for the MCG and NR for the SCG, so that LTE and NR can be used simultaneously.In NR, there can be up to 16 serving cells per cell group (i.e., MCG or SCG) (PCells and SCells for MCG; PSCells and SCells for SCG).

[0027] Although not illustrated in this drawing, an RRC (radio resource control, hereinafter referred to as RRC) layer exists above the PDCP layer of the terminal and the base station, respectively, and the RRC layer can exchange configuration control messages related to connection and measurement for radio resource control. For example, a measurement can be instructed to the terminal using a message from the RRC layer, and the terminal can report the measurement results to the base station using a message from the RRC layer.

[0028] FIG. 1c is an example diagram of the downlink and uplink channel frame structure when performing beam-based communication in an NR system according to one embodiment of the present invention.

[0029] Referring to FIG. 1c, the base station (1c-01) transmits signals in the form of beams to transmit wider coverage or stronger signals (1c-11)(1c-13)(1c-15)(1c-17). Accordingly, the terminal (1c-03) in the cell must transmit and receive data using a specific beam transmitted by the base station (in this example drawing, beam #1 (1c-13)).

[0030] Meanwhile, the terminal's state is divided into sleep mode (RRC_IDLE) and connected mode (RRC_CONNECTED) depending on whether the terminal is connected to the base station. Accordingly, the base station does not know the location of a terminal in sleep mode.

[0031] If a terminal in sleep mode intends to transition to connection mode, the terminal receives synchronization signal blocks (SSBs) (1c-21), (1c-23), (1c-25), and (1c-27) transmitted by the base station. These SSBs are SSB signals transmitted periodically according to a period set by the base station, and each SSB is divided into a primary synchronization signal (PSS) (1c-41), a secondary synchronization signal (SSS) (1c-43), and a physical broadcast channel (PBCH).

[0032] In this example diagram, a scenario in which an SSB is transmitted for each beam is assumed. For instance, it is assumed that SSB#0 (1c-21) is transmitted using Beam #0 (1c-11), SSB#1 (1c-23) is transmitted using Beam #1 (1c-13), SSB#2 (1c-25) is transmitted using Beam #2 (1c-15), and SSB#3 (1c-27) is transmitted using Beam #3 (1c-17). In this example diagram, it is assumed that a terminal in sleep mode is located at Beam #1; however, even when a terminal in connection mode performs random access, the terminal selects the SSB received at the time of performing the random access.

[0033] Accordingly, in this diagram, SSB #1 transmitted via Beam #1 is received. Upon receiving SSB #1, the terminal obtains the physical cell identifier (PCI) of the base station through PSS and SSS, and by receiving the PBCH, it can identify the identifier of the currently received SSB (i.e., #1), as well as the location within a 10 ms frame where the current SSB was received, and which SFN (system frame number) with a period of 10.24 seconds it is in. In addition, the PBCH contains a master information block (MIB), and this MIB indicates where SIB1 (system information block type 1), which broadcasts more detailed cell configuration information, can be received. Upon receiving SIB1, the terminal can determine the total number of SSBs transmitted by the base station and identify the location of the PRACH occasion (physical random access channel) where random access can be performed to transition to a connection mode state (more precisely, where a preamble, a physical signal specially designed to match uplink synchronization, can be transmitted) (in this example diagram, assuming a scenario where it is allocated every 1ms: (1c-30) to (1c-39)). In addition, based on the above information, it can determine which PRACH occasion among the above PRACH occasions is mapped to which SSB index. For example, in this example diagram, a scenario where it is allocated every 1ms is assumed, and a scenario where 1 / 2 SSB is allocated per PRACH Occasion (i.e., 2 PRACH Occasions per SSB) is assumed. Accordingly, a scenario in which 2 PRACH occasions are allocated per SSB starting from the beginning of the PRACH Occasion that starts according to the SFN value is illustrated.That is, (1c-30)(1c-31) is allocated for SSB#0, (1c-32)(1c-33) is allocated for SSB#1, and so on. After setting for all SSBs, PRACH Occasion is allocated again for the first SSB (1c-38)(1c-39).

[0034] Accordingly, the terminal recognizes the location of the PRACH occasion (1c-32) (1c-33) for SSB#1 and, accordingly, transmits a random access preamble to the earliest PRACH Occasion (1c-32) (1c-33) corresponding to SSB#1 at the current time (e.g., (1c-32)). Since the base station receives the preamble at the PRACH Occasion of (1c-32), it knows that the terminal selected SSB#1 and transmitted the preamble, and accordingly, transmits and receives data through the corresponding beam during the subsequent random access operation.

[0035] Meanwhile, when a connected terminal moves from the current (source) base station to the destination (target) base station due to reasons such as a handover, the terminal performs random access at the target base station and executes the operation of selecting an SSB as described above to transmit random access. Furthermore, during a handover, a handover command is transmitted to the terminal to move from the source base station to the target base station; at this time, the message may assign a dedicated random access preamble identifier for each SSB of the target base station to be used when performing random access at the target base station. In this case, the base station may not assign a dedicated random access preamble identifier to all beams (depending on the terminal's current location, etc.), and accordingly, a dedicated random access preamble may not be assigned to some SSBs (e.g., dedicated random access preamble assigned only to Beams #2 and #3). If a dedicated random access preamble is not assigned to the SSB selected by the terminal for preamble transmission, a contention-based random access preamble is randomly selected to perform random access. For example, in this diagram, a scenario is possible where the terminal is initially located at Beam #1 to perform random access but fails, and then, upon transmitting the random access preamble again, is located at Beam #3 to transmit a dedicated preamble. Random access. That is, even within a single random access procedure, if preamble retransmission occurs, contention-based random access procedures and contention-based random access procedures may coexist depending on whether a dedicated random access preamble is allocated to the selected SSB for each preamble transmission.

[0036] FIG. 1d is an example diagram illustrating a procedure for a non-mobile NR light terminal to perform a connection to a network according to one embodiment of the present invention.

[0037] Referring to FIG. 1d, the description assumes a scenario in which the terminal connects to a network while the power is first turned on, but the content of the present invention is not limited to this. A non-mobile NR Lite terminal in a dormant state selects a base station that supports NR Lite, camps at that base station, and attempts to establish a connection to the base station to register with the network. When establishing the connection, the terminal performs a random access procedure to the base station, transmits a connection establishment request message (RRCSetupRequest) of the RRC layer, receives a connection establishment message (RRCSetup) from the base station, and transmits a connection establishment completion message (RRCSetupComplete) back to the base station to complete the RRC connection establishment procedure (1d-11). At this time, the terminal may report the mobility-state of the terminal in the connection establishment completion message, and may indicate that the terminal is a fixed terminal. Although not illustrated in this drawing, the reconnection completion message (RRCResumeComplete), which is used when transitioning from the inactive state (RRC_INACTIVE) of the sleep state and the connected state to the connected state, may also include the terminal's mobility information as described above. Furthermore, after transitioning to the connected state, the terminal may indicate within UEAssistanceInformation that it is a stationary or fixed UE terminal as part of the data transmitted to the base station for information on previously visited cells (visitedCellInfoList) to provide the terminal's mobility state. In order to determine whether it is a stationary or fixed UE as described above, the terminal may determine whether it is a stationary or fixed UE based on information pre-configured in the terminal memory.Alternatively, the terminal may determine whether it is a stationary or fixed UE based on the number of times it (re)selects cells while moving between them within a given time. Furthermore, in order to report as a stationary or fixed UE within the aforementioned RRCSetupComplete and RRCResumeComplete messages, the terminal may report only if the base station broadcasts via an SIB message that it supports stationary or fixed terminals. If the base station does not report that it supports stationary or fixed terminals, the terminal may report mobility based on the number of times it (re)selects cells while moving between them within a given time, or it may always report as normal (or low) mobility.

[0038] Meanwhile, the above connection establishment completion message includes a registration request message transmitted to the core network, and this message is carried in the INITIAL UE message, which is a message between the base station and the AMF, and transmitted to the AMF (1d-13). If the terminal indicates that it is a stationary or fixed UE in the RRCSetupComplete message as in the example above, the base station may include this information in the INITIAL UE message and transmit it.

[0039] Upon receiving the message, the AMF sends an initial context setup request message to the base station to complete the registration of the terminal (1d-15). If the terminal has been previously registered, the AMF stores the wireless capability information (UE radio capability) of the terminal received from the terminal and includes this information in the initial context setup request message and transmits it to the base station. However, in this example diagram, since the scenario is one where the terminal has initially connected to the network, the AMF has not yet acquired the wireless capability information (UE radio capability) of the terminal, so the initial context setup request message is transmitted to the base station (1d-03) without the UE radio capability information.

[0040] In order for a base station to communicate with a terminal, it must know what capabilities the terminal possesses in order to perform communication. Therefore, the base station transmits a UECapabilityEnquiry message of the RRC layer to request UE radio capability information from the terminal (1d-21). Accordingly, the terminal transmits the UE radio capability information possessed by the terminal to the base station in a UECapabilityInformation message of the RRC layer (1d-23). ​​At this time, the terminal can indicate that it is an NR-light terminal and additionally indicate that the terminal is a stationary or fixed UE. The capability of the terminal indicating that it is a stationary or fixed UE is a parameter that can be commonly set without distinction between FDD and TDD, and is a parameter that can be commonly set without distinction between FR1, where the operating frequency is 7 GHz or lower, and FR2, where it is 7 GHz or higher.

[0041] The base station that receives the information stores the received information in the base station and transmits the information to the AMF using a UE Radio Capability IE (information element: unit of information transmission within a message) within the UE RADIO CAPABILITY INFO INDICATION message so that the AMF can store the information for reuse later (1d-25). Additionally, since the information can be utilized in the paging transmission procedure described later, the base station can generate information indicating whether the UE is stationary or fixed based on the UE radio capability information received from the terminal, including information in the UE Radio Capability for Paging IE, and transmit it to the AMF. Furthermore, it can additionally transmit information including the location to which the terminal is connected (e.g., base station identifier, physical channel identifier, etc.).

[0042] Additionally, when the base station configures various functions for the terminal based on the information, it may not configure functions necessary for mobility. For example, to determine whether the terminal needs to move to another base station, the base station may configure the terminal to report the results of measuring the signal strength of surrounding base stations according to specific conditions. The above procedure can be performed using the RRCReconfiguration message of the RRC layer (1d-31). However, in the case of a stationary or fixed UE as described above, the base station may not configure the terminal to measure the signal strength of surrounding base stations for this purpose. Furthermore, to this end, the base station may explicitly include an indicator in the RRCReconfiguration message to prevent the terminal from performing such measurements. Upon receiving the RRCReconfiguration message, the terminal transmits an RRCReconfigurationComplete message indicating that it has successfully received it (1d-33).

[0043] Afterwards, the base station can determine the amount of data transmission and reception of the terminal and, when there is no further activity, send the terminal back to sleep mode. This can be indicated using the RRCRelease message of the RRC layer (1d-41). From then on, the terminal periodically receives paging messages from the camping cell to check whether there is data to be transmitted to the terminal from the network (1d-51) and checks for the existence of data (1d-53).

[0044] Meanwhile, after the terminal transitions from sleep mode, the gNB (1d-03) deletes all information related to the terminal. Consequently, if the terminal moves and camps in another cell, the network cannot determine the terminal's location. To address this, whenever the terminal in a sleep state moves between cells, it determines whether the tracking-area-code value included in the SIB message transmitted by the corresponding base station has changed. If it has changed, it performs a procedure to reconnect to the network and re-register the location. Then, the network can transmit paging messages to the terminal by sending them to all base stations using the same tracking-area-code. The number of base stations managed by a single AMF may vary depending on the operator's operating method, but it can be a very large number of base stations. However, in the case of a non-mobile terminal as in the present invention, paging messages can be transmitted only to the base station that performed the last connection. To this end, when transmitting the initial paging message, the paging is transmitted only to the base station that performed the last connection, and if no response is received (after one or more attempts), the range of transmission for the paging message can be expanded to include the base stations of the terminal's last location tracking code.

[0045] Meanwhile, although not described in this drawing, as previously mentioned, when a terminal in sleep mode moves physically, it has a procedure to (re)select a nearby cell. As described above, in the case of a stationary or fixed UE, the procedure to (re)select such a cell may not be performed at all, or the cell (re)selection procedure may be performed at a much slower frequency than that of a general terminal. If the cell (re)selection procedure is performed, the method of determining cell (re)selection may change depending on the terminal's movement speed (e.g., the number of times the cell (re)selection was performed within a set time). For example, in the case of a fast-moving terminal, since the determination must be made quickly, it may be necessary to make the measurement time required for the cell (re)selection judgment relatively short. In addition, for a fast-moving terminal, the value broadcast by the base station (q-HystSF) is added to the current cell's received signal strength (in reality, it is subtracted because the broadcast value is a negative value), thereby determining that the current base station's received signal strength is relatively lower than that of surrounding cells, which can increase the probability of selecting surrounding cells. To additionally consider a terminal without mobility as in the present invention, the base station may separately instruct values ​​related to the q-HystSF and measurement time length for the terminal. Alternatively, if not separately instructed, the terminal may always use a specific value (e.g., normal mobility) regardless of the broadcast information.

[0046] FIG. 1e is an example diagram of the procedure sequence of a terminal and a base station when a non-mobile NR light terminal performs a connection to a network according to one embodiment of the present invention.

[0047] Referring to FIG. 1e, the description assumes a scenario in which the terminal connects to a network while the power is first turned on, but the content of the present invention is not limited to this. A non-mobile NR Lite terminal in a dormant state receives MIB and SIB1 transmitted by a base station, selects a base station that supports NR Lite, stays at that base station (camping) (1e-01), and attempts to establish a connection to the base station to register with the network (1e-05). When establishing the connection, the terminal performs a random access procedure to the base station, transmits a connection establishment request message (RRCSetupRequest) of the RRC layer, receives a connection establishment message (RRCSetup) from the base station, and transmits a connection establishment completion message (RRCSetupComplete) back to the base station to complete the RRC connection establishment procedure (1d-11). At this time, the terminal may report the mobility-state of the terminal in the connection establishment completion message, and may indicate that the terminal is a fixed terminal. Although not illustrated in this drawing, the reconnection completion message (RRCResumeComplete), which is used when transitioning from the inactive state (RRC_INACTIVE) of the sleep state and the connected state to the connected state, may also include the terminal's mobility information as described above. Furthermore, after transitioning to the connected state, the terminal may indicate within UEAssistanceInformation that it is a stationary or fixed UE terminal as part of the data transmitted to the base station for information on previously visited cells (visitedCellInfoList) to provide the terminal's mobility state. In order to determine whether it is a stationary or fixed UE as described above, the terminal may determine whether it is a stationary or fixed UE based on information pre-configured in the terminal memory.Alternatively, the terminal may determine whether it is a stationary or fixed UE based on the number of times it (re)selects cells while moving between them within a given time. Furthermore, in order to report as a stationary or fixed UE within the aforementioned RRCSetupComplete and RRCResumeComplete messages, the terminal may report only if the base station broadcasts via an SIB message that it supports stationary or fixed terminals. If the base station does not report that it supports stationary or fixed terminals, the terminal may report mobility based on the number of times it (re)selects cells while moving between them within a given time, or it may always report as normal (or low) mobility.

[0048] Meanwhile, the above connection establishment completion message includes a registration request message transmitted to the core network, and this message is carried in the INITIAL UE message, which is a message between the base station and the AMF, and transmitted to the AMF. If the terminal indicates that it is a stationary or fixed UE in the RRCSetupComplete message as in the example above, the base station may include this information in the INITIAL UE message and transmit it.

[0049] Upon receiving the message, the AMF sends an initial context setup request message to the base station to complete the registration of the terminal. If the terminal has been previously registered, the AMF stores the wireless capability information (UE radio capability) of the terminal received from the terminal and includes this information in the initial context setup request message and transmits it to the base station. However, in this example diagram, since the scenario is one where the terminal has initially connected to the network, the AMF has not yet acquired the wireless capability information (UE radio capability) of the terminal, so the initial context setup request message is transmitted to the base station (1d-03) without the UE radio capability information.

[0050] In order for a base station to communicate with a terminal, it must know what capabilities the terminal possesses in order to perform communication. Therefore, the base station transmits a UECapabilityEnquiry message of the RRC layer to request UE radio capability information from the terminal. Upon receiving this (1e-07), the terminal transmits the UE radio capability information possessed by the terminal to the base station in a UECapabilityInformation message of the RRC layer (1e-07). At this time, the terminal can indicate that it is an NR-light terminal and additionally indicate that the terminal is a stationary or fixed UE. The capability of the terminal indicating that it is a stationary or fixed UE is a parameter that can be commonly set without distinction between FDD and TDD, and is a parameter that can be commonly set without distinction between FR1, where the operating frequency is 7 GHz or lower, and FR2, where it is 7 GHz or higher.

[0051] The base station that receives the information stores the received information in the base station and transmits the information to the AMF using a UE Radio Capability IE (information element: unit of information transmission within a message) within the UE RADIO CAPABILITY INFO INDICATION message so that the AMF can store the information for reuse later (1d-25). Additionally, since the information can be utilized in the paging transmission procedure described later, the base station can generate information indicating whether the UE is stationary or fixed based on the UE radio capability information received from the terminal, including information in the UE Radio Capability for Paging IE, and transmit it to the AMF. Furthermore, it can additionally transmit information including the location to which the terminal is connected (e.g., base station identifier, physical channel identifier, etc.).

[0052] Afterwards, the function can be configured according to the RRC configuration information received from the base station (1e-09), and data transmission and reception can be performed (1e-11).

[0053] Meanwhile, if the base station decides to accept a connection request from a specific terminal as described above, it authorizes the connection (1e-53). Subsequently, if the UE capability is not received from the AMF as described above, the base station requests it from the terminal and receives it, and if the AMF has previously stored the information, it receives the relevant information from the AMF (1e-55). Accordingly, when the base station sets various functions for the terminal based on the information, it may not set functions necessary for mobility (1e-57). For example, to determine whether the terminal needs to move to another base station, the base station may set the terminal to report the results of measuring the signal strength of surrounding base stations according to specific conditions. The above procedure can be performed using the RRCReconfiguration message of the RRC layer (1e-61). However, in the case of a stationary or fixed UE as described above, the base station may not set the terminal to measure the signal strength of surrounding base stations for this purpose (1e-59). Furthermore, for this purpose, the base station may explicitly include an indicator in the RRCReconfiguration message to prevent the terminal from performing such measurements. The terminal that receives the above RRCReconfiguration message sends an RRCReconfigurationComplete message indicating that it has successfully received it. Afterwards, data transmission and reception is performed with the terminal according to the configured information (1e-63).

[0054] FIG. 1f illustrates the block configuration of a terminal in a wireless communication system according to an embodiment of the present invention.

[0055] Referring to FIG. 1f, the terminal includes an RF (radio frequency) processing unit (1f-10), a baseband processing unit (1f-20), a storage unit (1f-30), and a control unit (1f-40).

[0056] The RF processing unit (1f-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (1f-10) up-converts the baseband signal provided by the baseband processing unit (1f-20) into an RF band signal, transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (1f-10) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC (digital to analog converter), an ADC (analog to digital converter), etc. Although only one antenna is shown in FIG. 1f, the terminal may be equipped with multiple antennas. Additionally, the RF processing unit (1f-10) may include multiple RF chains. Furthermore, the RF processing unit (1f-10) may perform beamforming. For the above beamforming, the RF processing unit (1f-10) can adjust the phase and magnitude of each of the signals transmitted and received through a plurality of antennas or antenna elements.

[0057] The baseband processing unit (1f-20) performs a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the system. For example, when transmitting data, the baseband processing unit (1f-20) generates complex symbols by encoding and modulating the transmitted bit sequence. Additionally, when receiving data, the baseband processing unit (1f-20) restores the received bit sequence by demodulating and decoding the baseband signal provided by the RF processing unit (1f-10). For example, in the case of following the orthogonal frequency division multiplexing (OFDM) method, when transmitting data, the baseband processing unit (1f-20) generates complex symbols by encoding and modulating the transmitted bit sequence, maps the complex symbols to subcarriers, and then constructs OFDM symbols through inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. Additionally, upon receiving data, the baseband processing unit (1f-20) divides the baseband signal provided by the RF processing unit (1f-10) into OFDM symbol units, restores the signals mapped to subcarriers through a fast Fourier transform (FFT) operation, and then restores the received bit sequence through demodulation and decoding.

[0058] The baseband processing unit (1f-20) and the RF processing unit (1f-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (1f-20) and the RF processing unit (1f-10) may be referred to as a transmitting unit, a receiving unit, a transmitting and receiving unit, or a communication unit. Furthermore, at least one of the baseband processing unit (1f-20) and the RF processing unit (1f-10) may include a plurality of communication modules to support a plurality of different wireless access technologies. Additionally, at least one of the baseband processing unit (1f-20) and the RF processing unit (1f-10) may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include wireless LAN (e.g., IEEE 802.11), cellular network (e.g., LTE), etc. In addition, the above different frequency bands may include super high frequency (SHF) bands (e.g., 2.5 GHz, 5 GHz) and millimeter wave (e.g., 60 GHz) bands.

[0059] The storage unit (1f-30) stores data such as basic programs, application programs, and configuration information for the operation of the terminal. In particular, the storage unit (1f-30) can store information related to a wireless LAN node that performs wireless communication using wireless LAN connection technology. Additionally, the storage unit (1f-30) provides the stored data upon a request from the control unit (1f-40).

[0060] The control unit (1f-40) controls the overall operations of the terminal. For example, the control unit (1f-40) transmits and receives signals through the baseband processing unit (1f-20) and the RF processing unit (1f-10). Additionally, the control unit (1f-40) writes and reads data to and from the storage unit (1f-40). To this end, the control unit (1f-40) may include at least one processor. For example, the control unit (1f-40) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as applications. According to an embodiment of the present invention, the control unit (1f-40) includes a multiple connection processing unit (1f-42) that performs processing for operating in a multiple connection mode. For example, the control unit (1f-40) can control the terminal to perform the procedure illustrated in the operation of the terminal illustrated in FIG. 1e.

[0061] The control unit (1f-40) according to an embodiment of the present invention informs the network that the terminal is a fixed or stationary terminal when connecting to the network or transmitting capability through the values ​​in the received MIB and SIB1, thereby providing information for reference when the network transmits setting and paging information.

[0062] Methods according to the embodiments described in the claims or specification of the present invention may be implemented in the form of hardware, software, or a combination of hardware and software.

[0063] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present invention.

[0064] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (read-only memory), electrically erasable programmable read-only memory (EEPROM), magnetic disc storage devices, compact disc-ROMs (CD-ROMs), digital versatile discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0065] In addition, the above program may be stored on an attachable storage device that can be accessed via a communication network such as the internet, intranet, LAN (local area network), WLAN (wide LAN), or SAN (storage area network), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present invention through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present invention.

[0066] In the specific embodiments of the present invention described above, the components included in the invention are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present invention is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed in the singular form, or even if a component is expressed in the singular form, it may be composed in the plural form.

[0067] Meanwhile, although specific embodiments have been described in the detailed description of the present invention, it is understood that various modifications are possible within the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof.

Claims

Claim 1 A method performed by a terminal in a wireless communication system, comprising: transmitting a terminal capability information message to a base station containing information indicating that the terminal is in a fixed state; receiving a first Radio Resource Control (RRC) message from the base station containing information for setting the terminal not to perform a measurement of the signal strength of a neighboring base station based on the information included in the terminal capability information message; transmitting a second RRC message to the base station in response to the first RRC message; receiving a third RRC message from the base station for transitioning the terminal to an RRC Idle state; transitioning to an RRC Idle state based on the third RRC message; and receiving a paging message in the RRC Idle state, wherein the terminal in the fixed state receives the paging message from the base station that performed the last connection. Claim 2 A method according to claim 1, characterized in that the fixed state of the terminal is determined based on the number of cell re-selections during a predetermined period of time. Claim 3 delete Claim 4 delete Claim 5 A method performed by a base station in a wireless communication system, comprising: receiving a terminal capability information message from a terminal containing information indicating that the terminal is in a fixed state; transmitting a first Radio Resource Control (RRC) message to the terminal containing information for setting the terminal not to perform a measurement of the signal strength of a neighboring base station based on the information contained in the terminal capability information message; receiving a second RRC message from the terminal in response to the first RRC message; and transmitting a third RRC message to the terminal to transition the terminal to an RRC Idle state, wherein the terminal in the fixed state receives a paging message from the base station that performed the last connection. Claim 6 A method according to claim 5, characterized in that the fixed state of the terminal is determined based on the number of cell re-selections during a predetermined period of time. Claim 7 A method according to claim 5, further comprising the step of transmitting terminal wireless capability information, which includes information indicating that the terminal is in a fixed state, to an entity performing an Access and Mobility Management Function (AMF). Claim 8 delete Claim 9 A terminal in a wireless communication system comprises: a transceiver for transmitting and receiving signals; and a control unit connected to the transceiver; wherein the control unit transmits a terminal capability information message to a base station containing information indicating that the terminal is in a fixed state; receives a first Radio Resource Control (RRC) message from the base station containing information for setting the terminal not to perform a measurement of the signal strength of a neighboring base station based on the information included in the terminal capability information message; transmits a second RRC message to the base station in response to the first RRC message; receives a third RRC message from the base station for transitioning the terminal to an RRC Idle state; transitions to an RRC Idle state based on the third RRC message; receives a paging message in the RRC Idle state; and the terminal in the fixed state receives the paging message from the base station that performed the last connection. Claim 10 A terminal according to claim 9, characterized in that the fixed state of the terminal is determined based on the number of cell re-selections during a predetermined period of time. Claim 11 delete Claim 12 delete Claim 13 A base station in a wireless communication system comprises: a transceiver for transmitting and receiving signals; and a control unit connected to the transceiver; wherein the control unit receives a terminal capability information message containing information indicating that the terminal is in a fixed state, and, based on the information included in the terminal capability information message, transmits a first Radio Resource Control (RRC) message to the terminal containing information for setting the terminal not to perform a measurement of the signal strength of a neighboring base station, and in response to the first RRC message, receives a second RRC message from the terminal, and transmits a third RRC message to the terminal to transition the terminal to an RRC Idle state, and the terminal in the fixed state receives a paging message from the base station that performed the last connection. Claim 14 A base station characterized in that, in Clause 13, the fixed state of the terminal is determined based on the number of cell re-selections during a predetermined period of time. Claim 15 In claim 13, the control unit is an entity performing an Access and Mobility Management Function (AMF), and is characterized by transmitting terminal wireless capability information including information indicating that the terminal is in a fixed state.

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