CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application Nos. 10-2019-0076566 and 10-2019-0112893, which were filed in the Korean Intellectual Property Office on Jun. 26, 2019 and Sep. 11, 2019, respectively, the entire disclosure of each of which is incorporated herein by reference.

BACKGROUND

1. Field

The disclosure relates generally to an operation of a user equipment (UE) and a base station in a mobile communication system, and more particularly, to a method and apparatus for supporting idle mode mobility in a next-generation mobile communication system. In addition, the disclosure relates to a method and apparatus for random access in a wireless communication system.

2. Description of Related Art

To meet the increasing demand for wireless data traffic since deployment of 4thgeneration (4G) communication systems, efforts have been made to develop an improved 5th generation (5G) or pre-5G communication system. The 5G or pre-5G communication system may also be called a “beyond 4G network” or a “post long-term evolution (LTE) system”. The 5G communication system is intended to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, to accomplish higher data rates.

To decrease propagation loss of the radio waves and increase transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are being discussed in 5G communication systems.

In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation, etc.

In the 5G system, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) have been developed as an advanced access technology.

The Internet is now evolving to the Internet of things (IoT) where distributed entities, i.e., things, exchange and process information without human intervention. The Internet of everything (IoE) has also emerged, which is a combination of the IoT technology and big data processing technology through connection with a cloud server.

As technology elements, such as “sensing technology”, “wired/wireless communication and network infrastructure”, “service interface technology”, and “security technology” have been demanded for IoT implementation, a sensor network, a machine-to-machine (M2M) communication, machine type communication (MTC), etc., have been recently researched. Such an IoT environment may provide intelligent Internet technology services that collect and analyze data generated among connected things. IoT may be applied to a variety of fields including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, health care, smart appliances, and advanced medical services through convergence and combination between existing information technology (IT) and various industrial applications.

In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as a sensor network, MTC, and M2M communication may be implemented by beamforming, MIMO, and array antennas. Application of a cloud RAN as the above-described big data processing technology may also be considered an example of convergence of the 5G technology with the IoT technology.

A new radio (NR)-Lite UE, which is a low-cost and low-performance UE, is supported in a next-generation mobile communication system. Since the NR-Lite UE supports limited subcarrier spacing (SCS), frequency bandwidth, and maximum data rate for cost reduction, the NR-Lite UE should determine a cell, among neighboring cells, which can support the NR-Lite UE through a predetermined procedure.

In addition, since various services can be provided according to the details described above and the development of a mobile communication system, there is a need for a method for effectively providing the various services. For example, there is a need for a method for random access in a wireless communication system.

SUMMARY

An aspect of the disclosure is to provide a method and an apparatus for determining, by an NR-Lite UE, a cell supporting the NR-Lite UE, and providing information for the NR-Lite UE to measure neighboring cells through system information.

Another aspect of the disclosure is to provide a method and an apparatus for random access in a wireless communication system.

Another aspect of the disclosure is to provide a method and an apparatus for reporting two-step random access information in a next-generation mobile communication system.

Another aspect of the disclosure is to provide a method and an apparatus for performing a handover based on two-step random access in a next-generation mobile communication system.

In accordance with an aspect of the disclosure, a method of a terminal is provided. The method includes receiving, from a source base station, configuration information for a handover to a target base station, the configuration information including information on at least one of a first type random access procedure and a second type random access procedure, identifying a type of random access procedure based on the configuration information, and performing a random access procedure to the target base station based on the identified type of random access procedure.

In accordance with another aspect of the disclosure, a method of a target base station is provided. The method includes receiving, from a source base station, message requesting a handover from the source base station to the target base station, and transmitting, to the source base station, configuration information including information on at least one of a first type random access procedure and a second type random access procedure. The configuration information is transmitted from the source base station to a terminal, and a type of random access procedure performed by the terminal to the target base station is based on the configuration information.

In accordance with another aspect of the disclosure, a method of a source base station is provided. The method includes transmitting, to a target base station, message requesting a handover from the source base station to the target base station, receiving, from the target base station, configuration information including information on at least one of a first type random access procedure and a second type random access procedure, and transmitting, to a terminal, the configuration information. A type of random access procedure performed by the terminal to the target base station is based on the configuration information.

In accordance with another aspect of the disclosure, a terminal is provided. The terminal includes a transceiver and a controller configured to receive, from a source base station, configuration information for a handover to a target base station, the configuration information including information on at least one of a first type random access procedure and a second type random access procedure, identify a type of random access procedure based on the configuration information, and perform a random access procedure to the target base station based on the identified type of random access procedure.

In accordance with another aspect of the disclosure, a target base station is provided. The target base station includes a transceiver and a controller configured to receive, from a source base station, message requesting a handover from the source base station to the target base station, and transmit, to the source base station, configuration information including information on at least one of a first type random access procedure and a second type random access procedure. The configuration information is transmitted from the source base station to a terminal, and a type of random access procedure performed by the terminal to the target base station is based on the configuration information.

In accordance with another aspect of the disclosure, a source base station is provided. The source base station includes a transceiver and a controller configured to transmit, to a target base station, message requesting a handover from the source base station to the target base station, receive, from the target base station, configuration information including information on at least one of a first type random access procedure and a second type random access procedure, and transmit, to a terminal, the configuration information. A type of random access procedure performed by the terminal to the target base station is based on the configuration information.

