Patent Publication Number: US-2023140356-A1

Title: Method and apparatus for supporting supplementary uplink frequencies in next generation mobile communication system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 17/301,664, filed Apr. 9, 2021, now U.S. Pat. No. 11,546,838, which is a continuation of U.S. application Ser. No. 16/101,303, filed Aug. 10, 2018, now U.S. Pat. No. 10,979,967, which is based on and claims priority under 35 U.S.C. § 119(a) to Korean Patent Application No. 10-2017-0102623, filed on Aug. 11, 2017, in the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entirety. 
    
    
     BACKGROUND 
     1. Field 
     The present disclosure relates to a method and apparatus for supporting supplementary uplink frequencies between a terminal and a base station in a next generation mobile communication system. 
     2. Description of Related Art 
     In order to meet the increasing demand for wireless data traffic since the commercialization of 4 th  generation (4G) communication systems, the development focus is on the 5 th  generation (5G) or pre-5G communication system. For this reason, the 5G or pre-5G communication system is called a beyond 4G network communication system or post long-term evolution (LTE) system. 
     Implementation of the 5G communication system in millimeter wave (mmWave) frequency bands (e.g., 60 GHz bands) is being considered to accomplish higher data rates. In order to increase the propagation distance by mitigating propagation loss in the 5G communication system, discussions are underway about various techniques such as beamforming, massive multiple-input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large-scale antenna. 
     Also, in order to enhance network performance of the 5G communication system, developments are underway of various techniques such as evolved small cell, advanced small cell, cloud radio access network (RAN), ultra-dense network, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), and interference cancellation. 
     Furthermore, the ongoing research includes the use of hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) {FQAM} and sliding window superposition coding (SWSC) as advanced coding modulation (ACM), filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA). 
     Meanwhile, the Internet is evolving from a human-centric communication network in which information is generated and consumed by humans to the Internet of things (IoT) in which distributed things or components exchange and process information. The combination of the cloud server-based big data processing technology and the IoT begets Internet of everything (IoE) technology. In order to secure the sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology required for implementing the IoT, recent research has focused on sensor network, machine-to-machine (M2M), and machine-type communication (MTC) technologies. 
     In the IoT environment, it is possible to provide an intelligent Internet Technology that is capable of collecting and analyzing data generated from connected things to create new values for human life. The IoT can be applied to various fields such as smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart appliance, and smart medical service through legacy information technology (IT) and convergence of various industries. 
     Thus, there are various attempts to apply the IoT to the 5G communication system. For example, the sensor network, M2M, and MTC technologies are implemented by means of the 5G communication technologies such as beamforming, MIMO, and array antenna. The application of the aforementioned cloud RAN as a big data processing technology is an example of convergence between the 5G and IoT technologies. 
     Typically, in a mobile communication system, there is a coverage mismatch between downlink (DL) and uplink (UL), i.e., a DL coverage is broader than an UL coverage, and in order to overcome this coverage mismatch problem, the effective DL coverage is reduced in size for matching with the UL coverage. In this respect, in the next generation mobile communication system there is a need of a method and apparatus for enabling a terminal to use a UL frequency for broader coverage without such performance limitation. 
     SUMMARY 
     The present disclosure aims to provide a method for allowing a terminal to use a UL frequency for better service coverage to overcome the performance limitation caused by a UL-DL coverage mismatch that arises from a maximum transmit power restriction of the terminal in a next generation mobile communication system. 
     Also, the present disclosure aims to provide a method for preventing a legacy terminal from camping on an enhanced LTE (eLTE) base station that is connected to only a next generation (NG) core by combining a legacy information element (IE) and a new IE carried in system information broadcast by the base station in a next generation mobile communication system. 
     In accordance with an aspect of the present disclosure, a method for operating a base station capable of communicating with at least one of a first core network and a second core network in a wireless communication system comprises generating first information indicating whether a first type of terminal is barred from access to the base station and second information indicating whether a second type of terminal is barred from access to the base station, wherein the first type of terminal is capable of communicating with the first core network, and the second type of terminal is capable of communicating with both the first core network and the second core network; and transmitting a message including the generated first and second information to at least one terminal. 
     In accordance with another aspect of the present disclosure, a method by a terminal in a wireless communication system comprises identifying whether the terminal is a first type of terminal or a second type of terminal, wherein the first type of terminal is capable of communicating with a first core network, and the second type of terminal is capable of communicating with both the first core network and a second core network; receiving, from a base station, a message including first information indicating whether an access to the base station is barred for the first type and second information indicating whether an access to the base station is barred for the second type of terminal; and determining whether to access to the base station based on an identified type of terminal and one of the first information or the second information associated with the identified type of the terminal. 
     In accordance with still another aspect of the present disclosure, a base station capable of communicating with at least one of a first core network and a second core network in a wireless communication system, comprises a transceiver configured to transmit and receive signals; and a controller configured to generating first information indicating whether a first type of terminal is barred from access to the base station and second information indicating whether a second type is barred from access to the base station, wherein the first type of terminal is capable of communicating with the first core network, and the second type of terminal is type capable of communicating with both the first core network and the second core network; and transmitting, via the transceiver to at least one terminal, a message including the generated first and second information. 
     In accordance with yet still another aspect of the present disclosure, a terminal in a wireless communication system, comprises a transceiver configured to transmit and receive signals; and a controller configured to: identifying whether a type of the terminal is a first type or a second type, a terminal of the first type capable of communicating with a first core network, and a terminal of the second type capable of communicating with both the first core network and a second core network; receiving, via the transceiver from a base station, a message including first information indicating whether an access to the base station by the terminal of the first type is barred and second information indicating whether an access to the base station by the terminal of the second type is barred; and determining whether to access to the base station based on one of the first information and the second information associated with the identified type of the terminal. 
     Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. 
     Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device. 
     Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts: 
         FIG.  1 A  is an exemplary diagram illustrating architecture of a next generation mobile communication system; 
         FIGS.  1 BA- 1 BB  are exemplary conceptual views for explaining supplementary UL frequency that is employed in the embodiments of the present disclosure; 
         FIG.  1 C  is an exemplary conceptual diagram for explaining a method for use of a supplementary UL frequency (SUL) frequency and an NR UL in a next generation mobile communication system according to an embodiment of the present disclosure; 
         FIG.  1 D  is a signal flow diagram illustrating a procedure for use of an SUL frequency and an NR UL frequency according to an embodiment of the present disclosure; 
         FIG.  1 E  is an exemplary flowchart illustrating operations of a UE according to an embodiment of the present disclosure; 
         FIG.  1 F  is an exemplary conceptual diagram for explaining a method for use of an SUL frequency according to another embodiment of the present disclosure; 
         FIG.  1 G  is an exemplary block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure; 
         FIG.  1 H  is an exemplary block diagram illustrating a configuration of a Next Generation Node B (gNB) according to an embodiment of the present disclosure; 
         FIG.  2 A  is an exemplary diagram illustrating a next generation mobile communication network to which an LTE eNB is connected; 
         FIG.  2 B  is a signal flow diagram illustrating a procedure of prohibiting access of UEs that are not supported by a next generation mobile communication network according to an embodiment of the present disclosure; 
         FIG.  2 C  is a signal flow diagram illustrating a procedure of prohibiting access of a UE being supported by a next generation mobile communication system according to an embodiment of the present disclosure; 
         FIG.  2 D  is an exemplary flowchart illustrating an operation of a UE in a next generation mobile communication system according to an embodiment of the present disclosure; 
         FIG.  2 E  is an exemplary block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure; and 
         FIG.  2 F  is an exemplary block diagram illustrating a configuration of a gNB according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS.  1 A through  2 F , discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system or device 
     Exemplary embodiments of the present disclosure are described in detail with reference to the accompanying drawings. Detailed descriptions of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure. Further, the following terms are defined in consideration of the functionality in the present disclosure, and they may vary according to the intention of a user or an operator, usage, etc. Therefore, the definition should be made on the basis of the overall content of the present specification. 
     Advantages and features of the present disclosure and methods of accomplishing the same may be understood more readily by reference to the following detailed description of exemplary embodiments and the accompanying drawings. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the disclosure to those skilled in the art, and the present disclosure will only be defined by the appended claims. Like reference numerals refer to like elements throughout the specification. 
     First Embodiment 
       FIG.  1 A  is an exemplary diagram illustrating an exemplary architecture of a next generation mobile communication system. 
     In reference to  FIG.  1 A , a radio access network of the next generation mobile communication system includes a new radio node B (hereinafter, interchangeably referred to as NR NB)  1   a - 10  and a new radio core network (NR CN)  1   a - 05 . A new radio user equipment (NR UE)  1   a - 15  (hereinafter, interchangeably referred to as terminal) accesses an external network via the NR NB  1   a - 10  and the NR CN  1   a - 05 . 
     In  FIG.  1 A , the NR NB  1   a - 10  corresponds to an evolved node B (eNB) of a legacy LTE system. The NR UE  1   a - 15  connects to the NR NB  1   a - 10 , which provides more sophisticated service in comparison with the legacy eNB. In the next generation mobile communication system where all user traffic is served through shared channels, there is a need of an entity for collecting UE-specific status information (such as buffer status, power headroom status, and channel status) and scheduling the UEs based on the collected information, and the NR NB  1   a - 10  takes charge of such functions. 
     Typically, one NR NB hosts multiple cells. In order to meet the data rate requirement that is higher than that for legacy LTE, it is necessary to secure a maximum bandwidth broader than ever before by employing advanced technologies such as orthogonal frequency division multiplexing (OFDM) as a radio access scheme and beamforming. It may be possible to employ an adoptive modulation and coding (AMC) technology to determine a modulation scheme and a channel coding rate in adaptation to the channel condition of the UE. 
     The NR CN  1   a - 05  is responsible for mobility management, bearer setup, and QoS setup. The NR CN  1   a - 05  is responsible for other control functions as well as UE mobility management functions in connection with a plurality of NR NBs. The next generation mobile communication system may interoperate with legacy LTE systems in such a way as to connect the NR CN  1   a - 05  to a mobility management entity (MME)  1   a - 25  through a network interface. The MME  1   a - 25  is connected to an eNB  1   a - 30  as a legacy base station. 
       FIG.  1 BA- 1 BB  illustrate exemplary embodiments utilizing a supplementary UL frequency that is employed in the embodiments of the present disclosure. 
     In a mobile communication system, a UL-DL coverage mismatch may occur. The UL-DL coverage mismatch occurs because of a difference in channel characteristics between UL and DL or a limitation of the maximum transmit power of a terminal. In an exemplary case of a 3.5 GHz time division duplex (TDD) system, the DL coverage  1   b - 05  is broader than the UL coverage  1   b - 10 . 
     In this case, there is no problem in that a first UE  1   b - 20  receives services in both the UL and DL, but a problem may occur in that the second UE  1   b - 25  transmits UL data to the gNB  1   b - 15 . In order to mitigate the problem that arises from such coverage mismatch, the effective DL coverage is reduced in size for matching with the UL coverage. That is, although a wider service area can be provided in the downlink, the service area of the downlink is limited to a service area of the uplink. 
     In the next generation mobile communication system, a method is employed for a UE to use a UL frequency for broader coverage to overcome the performance limitation that arises from such mismatch. That is, the UE is capable of using a supplementary UL frequency of 1.8 giga-Hertz (GHz) in addition to the UL frequency of 3.5 GHz as denoted by reference number of  1   b - 30 . The supplementary UL frequency is referred to as SUL frequency. By the nature of frequency, the propagation distance of a radio signal increases as the frequency decreases. This means that a frequency of 1.8 GHz that is lower than the frequency of 3.5 GHz expands the coverage. As a consequence, the second UE  1   b - 50  is capable of transmitting data to the gNB  1   b - 40  successfully using the UL frequency of 1.8 GHz as denoted by reference number  1   b - 30 . 
     Regardless of the coverage issue, the first UE  1   b - 45  may select one of the 1.8 GHz frequency band or the 3.5 GHz frequency band for the purpose of distributing UL access congestion because it can use both the 1.8 GHz and 3.5 GHz UL frequency bands. The SUL frequency may be an LTE frequency. 
     In the case where a UE uses one of the SUL frequency and the NR UL frequency, there is a need of an operation for switching from the NR UL frequency to the SUL frequency at an NR UL coverage boundary. This may increase signaling overhead and cause a service breakdown. There is therefore a need of minimizing the number of UL frequency switching operations. 
     The present disclosure provides a method for using the NR UL frequency in the NR UL coverage area in which the SUL frequency is regarded as the default UL frequency. 
       FIG.  1 C  is an exemplary conceptual diagram for illustrating an exemplary method for use of an SUL frequency and an NR UL in a next generation mobile communication system according to an embodiment of the present disclosure. 
     The SUL frequency may provide a UL coverage similar in size to the DL coverage. For example, the SUL frequency of 1.8 GHz provides a UL coverage similar to that of the NR DL frequency of 3.5 GHz. Meanwhile, the NR UL frequency of 3.5 GHz cannot provide sufficient coverage. 
     The present disclosure may be characterized in that a UE performs a random access on an SUL frequency to transmit at least a physical uplink control channel (PUCCH). The SUL frequency is also used as a default frequency for transmitting a physical uplink shared channel (PUSCH) and, in response to a UE&#39;s request or gNB&#39;s command, it may be possible to use the NR UL frequency in addition to or instead of the SUL frequency for the PUSCH (data) transmission. 
       FIG.  1 D  is a signal flow diagram illustrating a procedure for use of a SUL frequency and an NR UL frequency according to an embodiment of the present disclosure. 
     At step  1   d - 15 , a gNB  1   d - 10  supporting the SUL frequency broadcasts system information including SUL frequency-specific random access channel (RACH) configuration information for use by the UEs located within its coverage. The system information may further include information on maximum transmit power value P_max required on the NR UL frequency and SUL frequency. A UE  1   d - 05  may determine whether it is located within the frequency-specific coverages based on the value of P_max. 
     The UE  1   d - 05  triggers an access at step  1   d - 20 . The UE  1   d - 05  performs a random access on the SUL frequency at step  1   d - 25 . The UE  1   d - 05  transits PUCCH and PUSCH on the SUL frequency at step  1   d - 30 . 
     According to a request generated by the gNB  1   d - 10  or the UE  1   d - 05 , the gNB  1   d - 10  determines to use the NR UL frequency for PUSCH transmission at step  1   d - 35 . This determination may be made by the gNB  1   d - 10  based on a cell-specific measurement information or buffer status report (BSR). This determination may be made by the UE  1   d - 05  when a UE&#39;s maximum transmit power (P_powerclass) value is greater than the P_max for the NR UL and, in this case, the UE  1   d - 05  may report the determination result to the gNB  1   d - 10 . If the above condition is fulfilled, this means that the UE  1   d - 05  is located within the NR UL coverage. 
     The gNB  1   d - 10  transmits PUSCH configuration information for the NR UL to the UE  1   d - 05  at step  1   d - 40 . The configuration information may include NR UL frequency information and an indication instructing the UE  1   d - 05  to perform random access. The configuration information may include an indication instructing the UE  1   d - 05  to perform random access with a physical downlink control channel (PDCCH) order. The PDCCH order may include the NR UL frequency information and RACH configuration information. 
     After completing the random access, the UE  1   d - 05  transmits PUSCH on the NR UL at step  1   d - 45 . The random access operation may be omitted. However, the PUCCH is still transmitted on the SUL frequency. In the present disclosure, the RACH configuration information denotes physical random access channel (PRACH) radio resource information, preamble information, and preamble transmit power information. 
       FIG.  1 E  is an exemplary flowchart illustrating an operation of a UE according to an embodiment of the present disclosure. 
     At step  1   e - 05 , the UE receives RACH configuration information for an SUL frequency via system information broadcast by a gNB. At step  1   e - 10 , the UE triggers an access. The UE performs a random access on the SUL frequency. At step  1   e - 20 , the UE transmits both the PUCCH and PUSCH on the SUL frequency. 
     At step  1   e - 25 , the UE receives, from the gNB, an instruction to add or switch to an NR UL for PUSCH transmission. This instruction is carried by a radio resource control (RRC) connection reconfiguration message including PUSCH configuration information, information on whether to perform a random access, and NR UL frequency information. In order to instruct to perform the random access, a PDCCH order is separately used. The PDCCH order includes the NR UL frequency information and RACH configuration information. 
     At step  1   e - 30 , the UE performs a random access on the NR UL. The random access operation may be omitted. At step  1   e - 35 , the UE transmits the PUSCH on the NR UL after completing the random access. 
       FIG.  1 F  is an exemplary conceptual diagram for illustrating an exemplary method for use of an SUL frequency according to another embodiment of the present disclosure. 
     It may be possible to design the UL and DL coverages to be matched using the NR frequency. However, there may be still a weak signal strength area such as a basement and a subway. In such an area, the UL signal is likely to be much weaker. Accordingly, it is preferred to use the SUL frequency for UL transmission in such an area. 
     In such a scenario, the NR UL frequency is used as a default UL frequency for PUCCH and PUSCH transmission, while the SUL frequency is used for PUCCH and PUSCH transmission in the weak UL signal strength area. However, the SUL frequency may be used for PUSCH transmission because the PUCCH can be in the weak signal strength area by nature of its robust reception performance in comparison with PUSCH. In this scenario, the roles of the SUL and NR UL frequencies are opposite to those in  FIGS.  1 D and  1 E . If the PUSCH reception performance drops in a certain area while transmitting PUCCH and PUSCH on the NR UL, the gNB configures to the UE to transmit the PUSCH on the SUL frequency. This configuration may be performed via the PDCCH order, which includes the SUL frequency information and RACH configuration information. 
       FIG.  1 G  is an exemplary block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure. 
     In reference to  FIG.  1 G , the UE includes a radio frequency (RF) processor  1   g - 10 , a baseband processor  1   g - 20 , a storage unit  1   g - 30 , and a controller  1   g - 40 . 
     The RF processor  1   g - 10  has a function for transmitting/receiving a signal over a radio channel such as band conversion and amplification of the signal. That is, the RF processor  1   g - 10  up-converts a baseband signal from the baseband processor  1   g - 20  to an RF band signal and transmits the RF signal via an antenna and down-converts the RF signal received via the antenna to a baseband signal. For example, the RF processor  1   g - 10  may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), and an analog-to-digital converter (ADC). 
     Although one antenna is depicted in the drawing, the UE may be provided with a plurality of antennas. The RF processor  1   g - 10  may also include a plurality of RF chains. The RF processor  1   g - 10  may perform beamforming. For beamforming, the RF processor  1   g - 10  may adjust the phase and size of a signal to be transmitted/received by means of the antennas or antenna elements in phase and size. The RF processor  1   g - 1 —may be configured to support a MIMO scheme with which the UE can receive multiple layers simultaneously 
     The baseband processor  1   g - 20  has a baseband signal-bit string conversion function according to a physical layer standard of the system. For example, in a data transmission mode, the baseband processor  1   g - 20  performs encoding and modulation on the transmission bit string to generate complex symbols. In a data reception mode, the baseband processor  1   g - 20  performs demodulation and decoding on the baseband signal from the RF processor  1   g - 10  to recover the transmitted bit string. In the case of using an OFDM scheme for data transmission, the baseband processor  1   g - 20  performs encoding and modulation on the transmission bit string to generate complex symbols, maps the complex symbols to subcarriers, performs inverse fast Fourier transform (IFFT) on the symbols, and inserts a cyclic prefix (CP) into the symbols to generate OFDM symbols. 
     In the data reception mode, the baseband processor  1   g - 20  splits the baseband signal from the RF processor  1   g - 10  into OFDM symbols, performs fast Fourier transform (FFT) on the OFDM symbols to recover the signals mapped to the subcarriers, and performs demodulation and decoding on the signals to recover the transmitted bit string. 
     The baseband processor  1   g - 20  and the RF processor  1   g - 10  process the transmission and reception signals as described above. Accordingly, the baseband processor  1   g - 20  and the RF processor  1   g - 10  may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. At least one of the baseband processor  1   g - 20  and the RF processor  1   g - 10  may include a plurality of communication modules for supporting different radio access technologies. 
     At least one of the baseband processor  1   g - 20  and the RF processor  1   g - 10  may also include multiple communication modules for processing the signals in different frequency bands. For example, the different radio access technologies may include a wireless local area network (WLAN) (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11) and a cellular network (e.g., LTE). The different frequency bands may include a super high frequency (SHF) band (e.g., 2.NRHz and NRhz bands) and an mmWave band (e.g., 60 GHz). 
     The storage unit  1   g - 30  stores data such as basic programs for operation of the UE, application programs, and setting information. The storage unit  1   g - 30  may also store the information on a second access node for radio communication with a second radio access technology. The storage unit  1   g - 30  provides the stored information in response to a request from the controller  1   g - 40 . 
     The controller  1   g - 40  controls overall operations of the UE. For example, the controller  1   g - 40  controls the baseband processor  1   g - 20  and the RF processor  1   g - 10  for transmitting and receiving signals. The controller  1   g - 40  writes and reads data to and from the storage unit  1   g - 40 . For this purpose, the controller  1   g - 40  may include at least one processor. For example, the controller  1   g - 40  may include a communication processor (CP) for controlling communications and an application processor (AP) for controlling higher layer programs such as applications. 
       FIG.  1 H  is an exemplary block diagram illustrating a configuration of gNB according to an embodiment of the present disclosure. 
     In reference to  FIG.  1 H , the gNB includes an RF processor  1   h - 10 , a baseband processor  1   h - 20 , a backhaul communication unit  1   h - 30 , a storage unit  1   h - 40 , and a controller  1   h - 50 . 
     The RF processor  1   h - 10  has a function for transmitting/receiving a signal over a radio channel such as band conversion and amplification of the signal. That is, the RF processor  1   h - 10  up-converts a baseband signal from the baseband processor  1   h - 20  to an RF band signal and transmits the RF signal via an antenna and down-converts the RF signal received via the antenna to a baseband signal. For example, the RF processor  1   h - 10  may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. 
     Although one antenna is depicted in the drawing, the gNB may be provided with a plurality of antennas. The RF processor  1   h - 10  may also include a plurality of RF chains. The RF processor  1   i - 10  may perform beamforming. For beamforming, the RF processor  1   h - 10  may adjust the phase and size of a signal to be transmitted/received by means of the antennas or antenna elements. The RF processor  1   h - 10  may be configured to transmit one or more layers for a downlink MIMO operation. 
     The baseband processor  1   h - 20  has a baseband signal-bit string conversion function according to a physical layer standard of the system. For example, in a data transmission mode, the baseband processor  1   h - 20  performs encoding and modulation on the transmission bit string to generate complex symbols. In a data reception mode, the baseband processor  1   h - 20  performs demodulation and decoding on the baseband signal from the RF processor  1   h - 10  to recover the transmitted bit string. In the case of using an OFDM scheme for data transmission, the baseband processor  1   h - 20  performs encoding and modulation on the transmission bit string to generate complex symbols, maps the complex symbols to subcarriers, performs inverse fast Fourier transform (IFFT) on the symbols, and inserts a cyclic prefix (CP) into the symbols to generate OFDM symbols. 
     In the data reception mode, the baseband processor  1   h - 20  splits the baseband signal from the RF processor  1   h - 10  into OFDM symbols, performs fast Fourier transform (FFT) on the OFDM symbols to recover the signals mapped to the subcarriers, and performs demodulation and decoding on the signals to recover the transmitted bit string. The baseband processor  1   h - 20  and the RF processor  1   h - 10  process the transmission and reception signals as described above. Accordingly, the baseband processor  1   h - 20  and the RF processor  1   h - 10  may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. 
     The backhaul communication unit  1   h - 30  provides an interface for communication with other nodes in the network. That is, the backhaul communication unit  1   h - 30  converts a bit string to be transmitted from the gNB to another node, e.g., another gNB and core network, to a physical signal and converts a physical signal received from another node to a bit string. 
     The storage unit  1   h - 40  stores data such as basic programs for operation of the gNB, application programs, and setting information. The storage unit  1   h - 40  may also store the information on the bearers established for UEs and measurement results reported by the connected UEs. The storage unit  1   h - 40  may also store the information for use by a UE in determining whether to enable or disable multi-connectivity. The storage unit  1   h - 40  may provide the stored data in reference to a request from the controller  1   h - 50 . 
     The controller  1   h - 50  controls overall operations of the gNB. For example, the controller  1   h - 50  controls the baseband processor  1   h - 20 , the RF processor  1   h - 10 , and the backhaul communication unit  1   h - 30  for transmitting and receiving signals. The controller  1   h - 50  writes and reads data to and from the storage unit  1   h - 40 . For this purpose, the controller  1   h - 50  may include at least one processor. 
     Second Embodiment 
       FIG.  2 A  is an exemplary diagram illustrating a next generation mobile communication network to which an LTE eNB is connected according to embodiments of the present disclosure. 
     A legacy LTE eNB  2   a - 15  connects to a mobility management entity (MME)  2   a - 05  as a network entity. It may be possible to upgrade a legacy LTE eNB such that the upgraded LTE eNB, as well as a next generation mobile communication base station, can connect to the next generation mobile communication network (NG core)  2   a - 10 . The upgraded LTE eNB is referred to as evolved/enhanced LTE (eLTE) eNB  2   a - 20 . 
     The eLTE eNB  2   a - 20  may connect to one or both of the legacy MME or next generation mobile communication network. If the eLTE eNB  2   a - 20  is only connected to the NG core, only an eLTE UE  2   a - 30  can connect to the eLTE eNB  2   a - 20  to communicate with the next generation mobile communication network. Meanwhile, although a legacy UE  2   a - 25  attempts to access to the eLTE eNB  2   a - 20 , it cannot communicate with the next generation mobile communication network. Accordingly, it is necessary to prevent the legacy UE  2   a - 25  from remaining camped on the eLTE eNB  2   a - 20  connected only to the NG core  2   a - 10 . 
     The present disclosure proposes a method for preventing a legacy LTE UE from camping on an eLTE eNB connected only to an NG core using a combination of a legacy IE and a new IE in the system information broadcast by the LTE eNB. 
     Table 1 shows the ASN.1 for system information block (SIB) 1 (SIB1) specified for the legacy LTE technology. In the present disclosure, new IEs are included in the SIB1. 
     
       
         
           
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 SystemInformationBlockType1 message 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 -- ASN1START 
               
               
                 SystemInformationBlockType1-BR-r13 ::= SystemInformationBlockType1 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1 ::= 
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                  cellAccessRelatedInfo 
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                   plmn-IdentityList 
                 PLMN-IdentityList, 
               
               
                   trackingAreaCode 
                 TrackingAreaCode, 
               
               
                   cellIdentity 
                 CellIdentity, 
               
               
                   cellBarred 
                 ENUMERATED {barred, notBarred}, 
               
               
                   intraFreqReselection 
                 ENUMERATED {allowed, notAllowed}, 
               
               
                   csg-Indication 
                 BOOLEAN, 
               
            
           
           
               
               
               
               
            
               
                   csg-Identity 
                 CSG-Identity 
                 OPTIONAL 
                 -- Need OR 
               
            
           
           
               
            
               
                  }, 
               
            
           
           
               
               
            
               
                  cellSelectionInfo 
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                   q-RxLevMin 
                 Q-RxLevMin, 
               
            
           
           
               
               
               
               
            
               
                   q-RxLevMinOffset 
                 INTEGER (1 . . . 8) 
                 OPTIONAL 
                 -- Need OP 
               
            
           
           
               
            
               
                  }, 
               
            
           
           
               
               
               
               
            
               
                  p-Max 
                 P-Max 
                 OPTIONAL, 
                 --Need OP 
               
            
           
           
               
               
            
               
                  freqBandIndicator 
                 FreqBandIndicator, 
               
               
                  schedulingInfoList 
                 SchedulingInfoList, 
               
            
           
           
               
               
               
               
            
               
                  tdd-Config 
                 TDD-Config 
                 OPTIONAL, 
                 -- Cond TDD 
               
            
           
           
               
               
            
               
                  si-WindowLength 
                 ENUMERATED { 
               
            
           
           
               
               
            
               
                   
                 ms1, ms2 , ms5, ms10, ms15, ms20, 
               
               
                   
                 ms40}, 
               
            
           
           
               
               
            
               
                  systemInfoValueTag 
                 INTEGER (0 . . . 31), 
               
            
           
           
               
               
               
            
               
                  nonCriticalExtension 
                 SystemInformationBlockType1-v890-IEs 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v890-IEs: := 
                 SEQUENCE { 
               
               
                  lateNonCriticalExtension 
                 OCTET STRING (CONTAINING SystemInformationBlockType1- 
               
               
                 v8h0-IEs) 
                 OPTIONAL, 
               
            
           
           
               
               
               
            
               
                  nonCriticalExtension 
                 SystemInformationBlockType1-v920-IEs 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
               
                 -- Late non critical extensions 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v8h0-IEs : := 
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                  multiBandInfoList 
                 MultiBandInfoList 
                 OPTIONAL, 
                 -- Need OR 
               
            
           
           
               
               
               
            
               
                  nonCriticalExtension 
                 SystemInformationBlockType1-v9e0-IEs 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v9e0-IEs : :=  
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                  freqBandIndicator-v9e0 
                 FreqBandIndicator-v9e0 
                 OPTIONAL, 
                 -- Cond FBI-max 
               
               
                  multiBandInfoList-v9e0 
                 MultiBandInfoList-v9e0 
                 OPTIONAL, 
                 -- Cond mFBI-max 
               
            
           
           
               
               
               
            
               
                  nonCriticalExtension 
                 SystemInformationBlockType1-v10j0-IEs 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v10j0-IEs : :=  
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                  freqBandInfo-r10 
                 NS-PmaxList-r10 
                 OPTIONAL, 
                 -- Need OR 
               
               
                  multiBandInfoList-v10j0 
                 MultiBandInfoList-v10j0 
                 OPTIONAL, 
                 -- Need OR 
               
            
           
           
               
               
               
            
               
                  nonCriticalExtension 
                 SEQUENCE { } 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
               
                 -- Regular non critical extensions 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v920-IEs : := 
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                  ims-EmergencySupport-r9 
                 ENUMERATED {true} 
                 OPTIONAL, 
                 -- Need OR 
               
               
                  cellSelectionInfo-v920 
                 CellSelectionInfo-v920 
                 OPTIONAL, 
                 -- Cond RSRQ 
               
            
           
           
               
               
               
            
               
                  nonCriticalExtension 
                 SystemInformationBlockType1-v1130-IEs 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v1130-IEs : :=  
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                  tdd-Config-v1130 
                 TDD-Config-v1130 
                 OPTIONAL, 
                 -- Cond TDD-OR 
               
               
                  cellSelectionInfo-v1130 
                 CellSelectionInfo-v1130 
                 OPTIONAL, 
                 -- Cond WB-RSRQ 
               
            
           
           
               
               
               
            
               
                  nonCriticalExtension 
                 SystemInformationBlockType1-v1250-IEs 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v1250-IEs : : = 
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                  cellAccessRelatedInfo-v1250 
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                   category0Allowed-r12 
                 ENUMERATED {true} 
                 OPTIONAL 
                 --  
               
            
           
           
               
            
               
                 Need OP 
               
               
                  }, 
               
            
           
           
               
               
               
               
            
               
                  cellSelectionInfo-v1250 
                 CellSelectionInfo-v1250 
                 OPTIONAL, 
                 -- Cond  
               
            
           
           
               
            
               
                 RSRQ2 
               
            
           
           
               
               
               
               
            
               
                  freqBandIndicatorPriority-r12 
                 ENUMERATED {true} 
                 OPTIONAL,  
                 -- Cond  
               
            
           
           
               
            
               
                 mFBI 
               
            
           
           
               
               
               
            
               
                  nonCriticalExtension 
                 SystemInformationBlockType1-v1310-IEs 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v1310-IEs : : = 
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                  hyperSFN-r13 
                 BIT STRING {SIZE (10)} 
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Need OR 
               
            
           
           
               
               
               
               
            
               
                  eDRX-Allowed-r13 
                 ENUMERATED {true} 
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Need OR 
               
            
           
           
               
               
               
            
               
                  cellSelectionInfoCE-r13 
                 CellSelectionInfoCE-r13 OPTIONAL, 
                 -- Need OP 
               
            
           
           
               
               
            
               
                  bandwidthReducedAccessRelatedInfo-r13 
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                   si-WindowLength-BR-r13 
                 ENUMERATED { 
               
            
           
           
               
               
            
               
                   
                 ms20, ms40, ms60, ms80, ms120, 
               
               
                   
                 ms160, ms200, spare}, 
               
            
           
           
               
               
            
               
                   si-RepetitionPattern-r13 
                 ENUMERATED {everyRF, every2ndRF, every4thRF, 
               
            
           
           
               
               
            
               
                   
                 every8thRF}, 
               
            
           
           
               
               
               
               
            
               
                   schedulingInfoList-BR-r13 
                 SchedulingInfoList-BR-r13  
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Need OR 
               
            
           
           
               
               
            
               
                   fdd-DownlinkOrTddSubframeBitmapBR-r13  
                 CHOICE { 
               
            
           
           
               
               
            
               
                    subframePattern10-r13 
                 BIT STRING (SIZE (10)), 
               
               
                    subframePattern40-r13 
                 BIT STRING (SIZE (40)) 
               
            
           
           
               
               
               
            
               
                   } 
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Need OP  
               
            
           
           
               
               
               
               
            
               
                   fdd-UplinkSubframeBitmapBR-r13 
                 BIT STRING (SIZE (10)) 
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Need OP 
               
            
           
           
               
               
            
               
                   startSymbolBR-r13 
                 INTEGER (1 . . . 4), 
               
               
                   si-HoppingConfigCommon-r13 
                 ENUMERATED {on,off}, 
               
            
           
           
               
               
               
               
            
               
                   si-ValidityTime-r13 
                 ENUMERATED {true} 
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Need OP 
               
            
           
           
               
               
               
               
            
               
                   systemInfoValueTagList-r13 
                 SystemInfoValueTagList-r13  
                 OPTIONAL 
                 --  
               
            
           
           
               
            
               
                 Need OR 
               
            
           
           
               
               
               
            
               
                  } 
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Cond BW-reduced 
               
            
           
           
               
               
            
               
                  nonCriticalExtension 
                 SystemInformationBlockType1-v1320-IEs 
               
            
           
           
               
            
               
                  OPTIONAL 
               
               
                 } 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v1320-IEs : :=  
                 SEQUENCE { 
               
               
                  freqHoppingParametersDL-r13 
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                   mpdcch-pdsch-HoppingNB-r13 
                 ENUMERATED {nb2, nb4} 
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Need OR 
               
               
                   interval-DLHoppingConfigCommonModeA-r13 CHOICE { 
               
            
           
           
               
               
            
               
                    interval-FDD-r13 
                 ENUMERATED {int1, int2, int4, int8}, 
               
               
                    interval-TDD-r13 
                 ENUMERATED {int1, int5, int10, int20} 
               
            
           
           
               
               
               
            
               
                   } 
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Need OR 
               
               
                   interval-DLHoppingConfigCommonModeB-r13 CHOICE { 
               
            
           
           
               
               
            
               
                    interval-FDD-r13 
                 ENUMERATED {int2, int4, int8, int16}, 
               
               
                    interval-TDD-r13 
                 ENUMERATED { int5, int10, int20, int40} 
               
            
           
           
               
               
               
            
               
                   } 
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Need OR 
               
            
           
           
               
               
            
               
                   mpdcch-pdsch-HoppingOffset-r13 
                 INTEGER (1 . . . maxAvailNarrowBands-r13) 
               
            
           
           
               
               
            
               
                  OPTIONAL 
                 -- Need OR 
               
            
           
           
               
               
               
            
               
                  } 
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Cond Hopping 
               
            
           
           
               
               
            
               
                  nonCriticalExtension 
                 SystemInformationBlockType1-v1350-IEs 
               
            
           
           
               
            
               
                         OPTIONAL 
               
               
                 } 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v1350-IEs : :=  
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                  cellSelectionInfoCE1-r13 
                 CellSelectionInfoCE1-r13 
                 OPTIONAL,  
                 --  
               
            
           
           
               
            
               
                 Need OP 
               
            
           
           
               
               
            
               
                  nonCriticalExtension 
                 SystemInformationBlockType1-v14xy-IEs 
               
            
           
           
               
            
               
                   OPTIONAL 
               
               
                 } 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v14xy-IEs : :=  
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                  eCallOverIMS-Support-r14 
                 ENUMERATED {true}  
                 OPTIONAL, 
                 --  
               
            
           
           
               
            
               
                 Need OR 
               
            
           
           
               
               
               
               
            
               
                  tdd-Config-v14xy 
                 TDD-Config-v14xy 
                 OPTIONAL,  
                 --  
               
            
           
           
               
            
               
                 Cond TDD-OR 
               
            
           
           
               
               
               
            
               
                  nonCriticalExtension 
                 SEQUENCE { } 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType1-v15xx-IEs : :=  
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                  cellBarred-r15 
                 ENUMERATED {barred, notBarred}, 
               
               
                  plmn-IdentityList 
                 PLMN-IdentityList5GCN, 
               
               
                  nonCriticalExtension 
                 SEQUENCE { } OPTIONAL 
               
            
           
           
               
               
            
               
                 PLMN-IdentityList : : = 
                 SEQUENCE (SIZE (1 . . . maxPLMN-r11)) OF PLMN-IdentityInfo 
               
               
                 PLMN-IdentityInfo : : = 
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                  plmn- Identity 
                 PLMN-Identity, 
               
               
                  cellReservedForOperatorUse 
                 ENUMERATED {reserved, notReserved} 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 PLMN-IdentityList5GCN  
                 : :=SEQUENCE(SIZE(1 . . . maxPLMN-r11)) OF PLMN-IdentifyInfo5GCN 
               
               
                 PLMN-IdentityInfo5GCN 
                 : :=SEQUENCE { 
               
            
           
           
               
               
            
               
                  plmn-Identity 
                 PLMN-Identity, 
               
               
                  cellReservedForOperatorUse  
                 ENUMERATE {reserved,notReserved}, 
               
               
                  cnType 
                 ENUMERATED {EPC,5GCN} 
               
            
           
           
               
               
            
               
                 SchedulingInfoList  
                 : := SEQUENCE (SIZE (1 . . . maxSI-Message)) OF SchedulingInfo 
               
            
           
           
               
            
               
                 SchedulingInfo : := SEQUENCE { 
               
            
           
           
               
               
            
               
                  si-Periodicity 
                 ENUMERATED { 
               
            
           
           
               
               
            
               
                   
                 rf8, rf16, rf32, rf64, rf128, rf256, rf512}, 
               
            
           
           
               
               
            
               
                  sib-MappingInfo 
                 SIB-MappingInfo 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 SchedulingInfoList-BR-r13  
                 : := SEQUENCE (SIZE (1 . . . maxSI-Message)) OF SchedulingInfo-BR-r13 
               
               
                 SchedulingInfo-BR-r13 : :=  
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                  si-Narrowband-r13 
                 INTEGER (1 . . . maxAvailNarrowBands-r13), 
               
               
                  si-TBS-r13 
                 ENUMERATED {b152, b208, b256, b328, b408, b504, b600,  
               
            
           
           
               
               
            
               
                   
                 b712, b808, b936} 
               
            
           
           
               
            
               
                 } 
               
               
                 SIB-MappingInfo : := SEQUENCE (SIZE (0 . . . maxSIB-1)) OF SIB-Type 
               
            
           
           
               
               
            
               
                 SIB-Type : := 
                 ENUMERATED { 
               
            
           
           
               
               
            
               
                   
                 sibType3, sibType4, sibType5, sibType6, 
               
               
                   
                 sibType7, sibType8, sibType9, sibType10, 
               
               
                   
                 sibType11, sibType12-v920, sibType13-v920, 
               
               
                   
                 sibType14-v1130, sibType15-v1130, 
               
               
                   
                 sibType16-v1130, sibType17-v1250, sibType18-v1250, 
               
               
                   
                 . . . , sibType19-v1250, sibType20-v1310, sibType21- 
               
            
           
           
               
            
               
                 v14x0} 
               
            
           
           
               
               
            
               
                 SystemInfoValueTagList-r13 : : = 
                 SEQUENCE (SIZE (1 . . . maxSI-Message)) OF 
               
            
           
           
               
            
               
                 SystemInfoValueTagSI-r13 
               
            
           
           
               
               
            
               
                 SystemInfoValueTagSI-r13 : := 
                 INTEGER (0 . . . 3) 
               
               
                 CellSelectionInfo-v920 : := 
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                  q-QualMin-r9 
                 Q-QualMin-r9, 
               
            
           
           
               
               
               
               
            
               
                  q-QualMinOffset-r9 
                 INTEGER (1 . . . 8) 
                 OPTIONAL 
                 --  
               
            
           
           
               
            
               
                 Need OP 
               
               
                 } 
               
            
           
           
               
               
            
               
                 CellSelectionInfo-v1130 : := 
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                  q-QualMinWB-r11 
                 Q-QualMin-r9 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 CellSelectionInfo-v1250 : := 
                 SEQUENCE { 
               
            
           
           
               
               
            
               
                  q-QualMinRSRQ-OnAllSymbols-r12 
                 Q-QualMin-r9 
               
            
           
           
               
            
               
                 } 
               
               
                 -- ASN1STOP 
               
               
                   
               
            
           
         
       
     
     If the eNB that broadcasts the SIB  1  is an eLTE eNB connected only to the NG core, the legacy cellBarred IE is set to ‘barred’ in the SIB1. This prohibits the legacy UEs from camping on the corresponding cell. The legacy UEs can understand only the legacy IEs including the cellBarred IE for use in prohibiting camping-on to the corresponding network. If the legacy cellBarred IE is set to ‘barred,’ even the emergency call service access is denied by the corresponding cell. 
     The eLTE eNB connected only to the NG core broadcasts newly specified cellBarred-r15 IE and plmn-IdentityList5GCN IE to support the eLTE UEs. The cell-Barred-r15 IE is configured for the purpose of prohibiting the eLTE UEs supported by the eLTE eNB connected only to the NG core from access or camp-on to the eLTE eNB, and the plmn-IdentityList5GCN is configured for the purpose of providing NG core-related public land mobile network (PLMN) information. 
     An eLTE eNB connected to both the MME and NG core may support both the legacy and eLTE UEs. The legacy cellBarred IE is set to ‘notBarred’ for any unusual purpose. The new cellBarred IE is also set to ‘notBarred.’ Meanwhile, the eLTE eNB connected only to the NG core cannot support the legacy UE but the eLTE UE. Accordingly, the legacy cellBarred IE is set to ‘barred.’ Also, the new cellBarred IE is set to ‘notBarred.’ 
     The eLTE UE ascertains the type of the network supported by the corresponding cell in consideration of the legacy plmn-IdentityList and the newly-defined plmn-IdentityList5GCN. The PLMN IDs included in the legacy plmn-IdentityList and newly-defined plmn-IdentityList5GCN IEs may be identical with or different from each other. This is determined by the operator. 
     The new PLMN configuration information may further include the information on the network entity, i.e., LTE MME or NG core entity, to which the corresponding PLMN is connected. This aims to make it possible for the eLTE UE to select one of the MME or NG core. 
     The eLTE UE transmits to the MME a non-access stratum (NAS) message generated in the legacy format and to the NG core the NAS message generated in a new format in order for the MME and the NG core to understand the NAS message. 
       FIG.  2 B  is a signal flow diagram illustrating an exemplary procedure of prohibiting access of UEs that are not supported by a next generation mobile communication network according to an embodiment of the present disclosure. 
     A legacy LTE UE  2   b - 05  that cannot communicate with an NG core  2   b - 15  selects a PLMN, i.e., selected PLMN, on an NAS layer at step  2   b - 20 . The selected PLMN is determined in consideration of a home PLMN (HPLMN) or HEPLMN recorded in a universal subscriber identity module (USIM). An eLTE eNB  2   b - 10  is connected only to the NG core  2   b - 15 . Accordingly, at step  2   b - 30 , the eLTE eNB  2   b - 10  broadcasts the SIB1 including the cellBarred IE set to ‘barred’. 
     The legacy UEs that receive the SIB1 may not attempt to camp on the corresponding cell. The legacy LTE UE  2   b - 05  measures neighboring cells and selects the eLTE cell with the best received signal strength at step S 2   b - 25 . Next, the legacy LTE UE  2   b - 05  receives the system information broadcast via the corresponding cell at step  2   b - 30 . Since the cellBarred IE included in the SIB1 is set to ‘barred’, the legacy LTE UE  2   b - 05  assumes that its access to the corresponding cell is barred and does not attempt to camp on the corresponding cell at step  2   b - 35 . The access barring for a UE is released after a predetermined time. The legacy LTE UE  2   b - 05  searches for another cell at step  2   b - 40 . 
       FIG.  2 C  is a signal flow diagram illustrating an exemplary procedure of prohibiting access of a UE being supported by a next generation mobile communication system according to an embodiment of the present disclosure. 
     An eLTE UE  2   c - 05  that is capable of communicating with an NG core  2   c - 15  selects a PLMN, i.e., selected PLMN, on a NAS layer at step  2   c - 20 . The selected PLMN is determined in consideration of a home PLMN (HPLMN) or HEPLMN recorded in a USIM. An eLTE eNB  2   c - 10  is connected only to the NG core  2   c - 15 . Accordingly, at step  2   c - 30 , the eLTE eNB  2   c - 10  broadcasts the SIB1 including the cellBarred IE set to ‘barred.’ The legacy UEs that receives the SIB1 may not attempt to camp on the corresponding cell. 
     The eLTE eNB  2   c - 10  may also set the new cellBarred-r15 IE to ‘notBarred’ in order for the eLTE UEs still to camp on the corresponding cell. In order to bar access of the eLTE UEs to the corresponding cell, the IE cellBarred-r15 IE is set to ‘barred.’ The eLTE UE  2   c - 05  measures neighboring cells and selects an eLTE cell with the best signal strength at step  2   c - 25 . Next, the eLTE UE  2   c - 20  receives the system information broadcast via the corresponding cell at step  2   c - 30 . Since the cellBarred IE is set to ‘barred’ and the cellBarred-r15 IE is set to ‘notBarred’ in the SIB1, the eLTE UE  2   c - 05  camps on the corresponding cell at step  2   c - 35 . 
     If at least one of the cellBarred IE and the cellBarred-r15 IE is set to ‘notBarred’, the eLTE assumes that its access to the corresponding cell is not barred. If the new IE is not configured, the procedure should be performed based on only the configuration information of the legacy IE. The access barring for a UE is released after a predetermined time. The eLTE UE  2   c - 05  performs a setup for communication with the NG core  2   c - 40 . 
     At step  2   c - 45 , the eLTE UE  2   c - 05  transmits to the NG core  2   c - 15  an Attach Request message including the information on the selected PLMN. The selected PLMN should be included in the newly introduced plmn-IdentityList5GCN for access to usual services. Otherwise, only limited services such an emergency call service, are allowed for the UE to access via the corresponding cell. At step  2   c - 50 , the NG core  2   c - 15  transmits to the UE  2   c - 05  an Attach Accept message including an ePLMN list. Here, the selected PLMN is regarded as a registered PLMN. 
       FIG.  2 D  is an exemplary flowchart illustrating an exemplary operation of a UE in a next generation mobile communication system according to an embodiment of the present disclosure. 
     At step  2   d - 05 , a UE NAS layer selects a PLMN, i.e., selected PLMN. The selected PLMN is determined in consideration of the HPLMN or HEPLMN registered in a USIM. At step  2   d - 10 , the UE selects a cell with a signal quality better than a predetermined level or a highest signal quality among the cells supporting the selected PLMN. 
     At step  2   d - 15 , the UE receives the SIB1 via the selected cell. At step  2   d - 20 , the UE determines whether the received SIB1 includes a cellBarred-r15 IE. If it is determined that the received SIB1 includes the cellBarred-r15 IE, the UE determines whether at least one of the cellBarred IE and the cellBarred-r15 included in the SIB1 is set to ‘notBarred’. If at least one of the cellBarred IE and the cellBarred-r15 is set to ‘notBarred’, the UE assumes at step  2   d - 30  that its access to the corresponding cell is not barred. If neither the cellBarred IE nor the cellBarred-r15 is set to ‘notBarred’, the UE assumes at step  2   d - 35  that its access to the corresponding cell is barred. 
     If it is determined that the received SIB1 includes no cellBarred-r15 IE, the UE determines at step  2   d - 40  whether the cellBarred IE is set to ‘notBarred’. If it is determined that the cellBarred IE is set to ‘notBarred’, the UE assumes at step  2   d - 45  that its access to the corresponding cell is not barred. If it is determined that the cellBarred IE is not set to ‘notBarred’, the UE assumes at step  2   d - 50  that its access to the corresponding cell is barred. 
       FIG.  2 E  is an exemplary block diagram illustrating an exemplary configuration of a UE according to an embodiment of the present disclosure. 
     The legacy UE and the eLTE UE according to an embodiment of the present disclosure may be configured as shown in  FIG.  2 E . 
     In reference to  FIG.  2 E , the UE includes a radio frequency (RF) processor  2   e - 10 , a baseband processor  2   e - 20 , a storage unit  2   e - 30 , and a controller  2   e - 40 . 
     The RF processor  2   e - 10  has a function for transmitting/receiving a signal over a radio channel such as band conversion and amplification of the signal. That is, the RF processor  2   e - 10  up-converts a baseband signal from the baseband processor  2   e - 20  to an RF band signal and transmits the RF signal via an antenna and down-converts the RF signal received via the antenna to a baseband signal. For example, the RF processor  2   e - 10  may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), and an analog-to-digital converter (ADC). 
     Although one antenna is depicted in the drawing, the UE may be provided with a plurality of antennas. The RF processor  2   e - 10  may also include a plurality of RF chains. The RF processor  2   e - 10  may perform beamforming. For beamforming, the RF processor  2   e - 10  may adjust the phase and size of a signal to be transmitted/received by means of the antennas or antenna elements in phase and size. The RF processor  2   e - 1 —may be configured to support a MIMO scheme with which the UE can receive multiple layers simultaneously 
     The baseband processor  2   e - 20  has a baseband signal-bit string conversion function according to a physical layer standard of the system. For example, in a data transmission mode, the baseband processor  2   e - 20  performs encoding and modulation on the transmission bit string to generate complex symbols. In a data reception mode, the baseband processor  2   e - 20  performs demodulation and decoding on the baseband signal from the RF processor  2   e - 10  to recover the transmitted bit string. In the case of using an OFDM scheme for data transmission, the baseband processor  2   e - 20  performs encoding and modulation on the transmission bit string to generate complex symbols, maps the complex symbols to subcarriers, performs inverse fast Fourier transform (IFFT) on the symbols, and inserts a cyclic prefix (CP) into the symbols to generate OFDM symbols. 
     In the data reception mode, the baseband processor  2   e - 20  splits the baseband signal from the RF processor  2   e - 10  into OFDM symbols, performs fast Fourier transform (FFT) on the OFDM symbols to recover the signals mapped to the subcarriers, and performs demodulation and decoding on the signals to recover the transmitted bit string. 
     The baseband processor  2   e - 20  and the RF processor  2   e - 10  process the transmission and reception signals as described above. Accordingly, the baseband processor  2   e - 20  and the RF processor  2   e - 10  may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. At least one of the baseband processor  2   e - 20  and the RF processor  2   e - 10  may include a plurality of communication modules for supporting different radio access technologies. 
     At least one of the baseband processor  2   e - 20  and the RF processor  2   e - 10  may also include multiple communication modules for processing the signals in different frequency bands. For example, the different radio access technologies may include a wireless local area network (WLAN) (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11) and a cellular network (e.g., LTE). The different frequency bands may include a super high frequency (SHF) band (e.g., 2.NRHz and NRhz bands) and an mmWave band (e.g., 60 GHz). 
     The storage unit  2   e - 30  stores data such as basic programs for operation of the UE, application programs, and setting information. The storage unit  2   e - 30  may also store the information on a second access node for radio communication with a second radio access technology. The storage unit  2   e - 30  provides the stored information in response to a request from the controller  2   e - 40 . 
     The controller  2   e - 40  controls overall operations of the UE. For example, the controller  2   e - 40  controls the baseband processor  2   e - 20  and the RF processor  2   e - 10  for transmitting and receiving signals. The controller  2   e - 40  writes and reads data to and from the storage unit  2   e - 40 . For this purpose, the controller  2   e - 40  may include at least one processor. For example, the controller  2   e - 40  may include a communication processor (CP) for controlling communications and an application processor (AP) for controlling higher layer programs such as applications. 
       FIG.  2 F  is an exemplary block diagram illustrating an exemplary configuration of a gNB according to an embodiment of the present disclosure. 
     According to an embodiment of the present disclosure, the gNB connected to at least one of an MME and an NG core may be configured as shown in  FIG.  2 F . As shown in the drawing, the gNB includes an RF processor  2   f - 10 , a baseband processor  2   f - 20 , a backhaul communication unit  2   f - 30 , a storage unit  2   f - 40 , and a controller  2   f - 50 . 
     The RF processor  2   f - 10  has a function for transmitting/receiving a signal over a radio channel such as band conversion and amplification of the signal. That is, the RF processor  2   f - 10  up-converts a baseband signal from the baseband processor  2   f - 20  to an RF band signal and transmits the RF signal via an antenna and down-converts the RF signal received via the antenna to a baseband signal. For example, the RF processor  2   f - 10  may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. 
     Although one antenna is depicted in the drawing, the gNB may be provided with a plurality of antennas. The RF processor  2   f - 10  may also include a plurality of RF chains. The RF processor  1   i - 10  may perform beamforming. For beamforming, the RF processor  2   f - 10  may adjust the phase and size of a signal to be transmitted/received by means of the antennas or antenna elements. The RF processor  2   f - 10  may be configured to transmit one or more layers for a downlink MIMO operation. 
     The baseband processor  2   f - 20  has a baseband signal-bit string conversion function according to a physical layer standard of the system. For example, in a data transmission mode, the baseband processor  2   f - 20  performs encoding and modulation on the transmission bit string to generate complex symbols. In a data reception mode, the baseband processor  2   f - 20  performs demodulation and decoding on the baseband signal from the RF processor  2   f - 10  to recover the transmitted bit string. In the case of using an OFDM scheme for data transmission, the baseband processor  2   f - 20  performs encoding and modulation on the transmission bit string to generate complex symbols, maps the complex symbols to subcarriers, performs inverse fast Fourier transform (IFFT) on the symbols, and inserts a cyclic prefix (CP) into the symbols to generate OFDM symbols. 
     In the data reception mode, the baseband processor  2   f - 20  splits the baseband signal from the RF processor  2   f - 10  into OFDM symbols, performs fast Fourier transform (FFT) on the OFDM symbols to recover the signals mapped to the subcarriers, and performs demodulation and decoding on the signals to recover the transmitted bit string. The baseband processor  2   f - 20  and the RF processor  2   f - 10  process the transmission and reception signals as described above. Accordingly, the baseband processor  2   f - 20  and the RF processor  2   f - 10  may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. 
     The backhaul communication unit  2   f - 30  provides an interface for communication with other nodes in the network. That is, the backhaul communication unit  2   f - 30  converts a bit string to be transmitted from the gNB to another node, e.g., another gNB and core network, to a physical signal and converts a physical signal received from another node to a bit string. 
     The storage unit  2   f - 40  stores data such as basic programs for operation of the gNB, application programs, and setting information. The storage unit  2   f - 40  may also store the information on the bearers established for UEs and measurement results reported by the connected UEs. The storage unit  2   f - 40  may also store the information for use by a UE in determining whether to enable or disable multi-connectivity. The storage unit  2   f - 40  may provide the stored data in reference to a request from the controller  2   f - 50 . 
     The controller  2   f - 50  controls overall operations of the gNB. For example, the controller  2   f - 50  controls the baseband processor  2   f - 20 , the RF processor  2   f - 10 , and the backhaul communication unit  2   f - 30  for transmitting and receiving signals. The controller  2   f - 50  writes and reads data to and from the storage unit  2   f - 40 . For this purpose, the controller  2   f - 50  may include at least one processor. 
     As described above, the present disclosure is advantageous in terms of overcoming a performance limitation caused by UL-DL coverage mismatch in such a way as to enable a terminal to use a UL frequency for broader coverage. 
     Also, the present disclosure is advantageous in terms of preventing a legacy terminal from accessing a next generation mobile communication network by configuring system information in such a way as to include a legacy IE and a new IE, the system information being broadcast by a base station. 
     The methods specified in the claims and specification can be implemented by hardware, software, or a combination of them. 
     In the case of being implemented in software, it may be possible to store at least one program (software module) in a computer-readable storage medium. The at least one program stored in the computer-readable storage medium may be configured for execution by at least one processor embedded in an electronic device. The at least one program includes instructions executable by the electronic device to perform the methods disclosed in the claims and specifications of the present disclosure. 
     Such a program (software module or software program) may be stored in a non-volatile memory such as random access memory (RAM) and flash memory, Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), a magnetic disc storage device, a Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs) or other type of optical storage device, and a magnetic cassette. It may also be possible to store the program in a memory device implemented in combination of part or whole of the aforementioned media. The storage unit may include a plurality of memories. 
     The program may be stored in an attachable storage device accessible through a communication network implemented as a combination of Internet, intranet, Local Area Network (LAN), Wireless LAN (WLAN), and Storage Area Network (SAN). The storage device may be attached to the device performing the methods according to embodiments of the present disclosure by means of an external port. It may also be possible for a separate storage device installed on a communication network to attach to the device performing the methods according to embodiments of the present disclosure. 
     In the embodiments of the present disclosures, the components are described in singular or plural forms depending on the embodiment. However, the singular and plural forms are selected appropriately for the proposed situation just for explanatory convenience without any intention of limiting the present disclosure thereto; thus, the singular form includes the plural form as well, unless the context clearly indicates otherwise. 
     Although the description has been made with reference to particular embodiments, the present disclosure can be implemented with various modifications without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the particular embodiments disclosed, and it will include the following claims and their equivalents. 
     Although the present disclosure has been described with various embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.