ABSTRACT
Abstract
The present disclosure relates to a 5G communication system or a 6G communication system for supporting higher data rates beyond a 4G communication system such as long term evolution (LTE). The present disclosure provides method and apparatus for SDT related procedures in next generation wireless communication system.
Description
PRIORITY
This application is a National Phase Entry of PCT International Application No. PCT/KR2022/002921, which was filed on Mar. 2, 2022, and claims priority to Korean Provisional Patent Application No. 10-2021-0029994, which was filed on Mar. 8, 2021, and Korean Patent Application No. 10-2021-0034260, which was filed on Mar. 16, 2021, the entire content of each of which is incorporated herein by reference.
TECHNICAL FIELD
The disclosure relates to a wireless communication system. Specifically, the disclosure relates to an apparatus, a method and a system for handling small data transmission (SDT) related procedures in wireless communication system.
BACKGROUND ART
Considering the development of wireless communication from generation to generation, the technologies have been developed mainly for services targeting humans, such as voice calls, multimedia services, and data services. Following the commercialization of 5G (5th-generation) communication systems, it is expected that the number of connected devices will exponentially grow. Increasingly, these will be connected to communication networks. Examples of connected things may include vehicles, robots, drones, home appliances, displays, smart sensors connected to various infrastructures, construction machines, and factory equipment. Mobile devices are expected to evolve in various form-factors, such as augmented reality glasses, virtual reality headsets, and hologram devices. In order to provide various services by connecting hundreds of billions of devices and things in the 6G (6th-generation) era, there have been ongoing efforts to develop improved 6G communication systems. For these reasons, 6G communication systems are referred to as beyond-5G systems.
6G communication systems, which are expected to be commercialized around 2030, will have a peak data rate of tera (1,000 giga)-level bps and a radio latency less than 100 μsec, and thus will be 50 times as fast as 5G communication systems and have the 1/10 radio latency thereof.
In order to accomplish such a high data rate and an ultra-low latency, it has been considered to implement 6G communication systems in a terahertz band (for example, 95 GHz to 3 THz bands). It is expected that, due to severer path loss and atmospheric absorption in the terahertz bands than those in mmWave bands introduced in 5G, technologies capable of securing the signal transmission distance (that is, coverage) will become more crucial. It is necessary to develop, as major technologies for securing the coverage, radio frequency (RF) elements, antennas, novel waveforms having a better coverage than orthogonal frequency division multiplexing (OFDM), beamforming and massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antennas, and multiantenna transmission technologies such as large-scale antennas. In addition, there has been ongoing discussion on new technologies for improving the coverage of terahertz-band signals, such as metamaterial-based lenses and antennas, orbital angular momentum (OAM), and reconfigurable intelligent surface (RIS).
Moreover, in order to improve the spectral efficiency and the overall network performances, the following technologies have been developed for 6G communication systems: a full-duplex technology for enabling an uplink transmission and a downlink transmission to simultaneously use the same frequency resource at the same time; a network technology for utilizing satellites, high-altitude platform stations (HAPS), and the like in an integrated manner; an improved network structure for supporting mobile base stations and the like and enabling network operation optimization and automation and the like; a dynamic spectrum sharing technology via collision avoidance based on a prediction of spectrum usage; an use of artificial intelligence (AI) in wireless communication for improvement of overall network operation by utilizing AI from a designing phase for developing 6G and internalizing end-to-end AI support functions; and a next-generation distributed computing technology for overcoming the limit of UE computing ability through reachable super-high-performance communication and computing resources (such as mobile edge computing (MEC), clouds, and the like) over the network. In addition, through designing new protocols to be used in 6G communication systems, developing mechanisms for implementing a hardware-based security environment and safe use of data, and developing technologies for maintaining privacy, attempts to strengthen the connectivity between devices, optimize the network, promote softwarization of network entities, and increase the openness of wireless communications are continuing.
It is expected that research and development of 6G communication systems in hyper-connectivity, including person to machine (P2M) as well as machine to machine (M2M), will allow the next hyper-connected experience. Particularly, it is expected that services such as truly immersive extended reality (XR), high-fidelity mobile hologram, and digital replica could be provided through 6G communication systems. In addition, services such as remote surgery for security and reliability enhancement, industrial automation, and emergency response will be provided through the 6G communication system such that the technologies could be applied in various fields such as industry, medical care, automobiles, and home appliances.
Meanwhile, there have been various studies on SDT related procedures for enhanced wireless communication system recently.
The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure.
DISCLOSURE OF INVENTION
Technical Problem
There are needs to enhance SDT procedure for next generation wireless communication system.
Solution to Problem
Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide a communication method and system for converging a sixth generation (6G) and a fifth generation (5G) communication system for supporting higher data rates beyond a fourth generation (4G).
In accordance with an aspect of the disclosure, a method performed by a terminal is provided. The method comprises: receiving, from a base station, a radio resource control (RRC) message including first information configuring a configured grant (CG) resource for small data transmission (SDT) and second information configuring a timing alignment timer (TAT) for SDT (TAT-SDT); starting, while the terminal is in an RRC inactive state, the TAT-SDT based on the second information; while an SDT procedure is ongoing based on the first information, releasing the CG resource for SDT upon expiry of the TAT-SDT; and identifying whether a response is received for an initial uplink packet transmitted to the base station during the SDT procedure, wherein, in case that the response is received, the ongoing SDT procedure is not terminated and a dynamic grant (DG) is used for the ongoing SDT procedure.
In accordance with an aspect of the disclosure, a method performed by a base station is provided. The method comprises: transmitting, to a terminal, a radio resource control (RRC) message including first information configuring a configured grant (CG) resource for small data transmission (SDT) and second information configuring a timing alignment timer (TAT) for SDT (TAT-SDT), wherein the TAT-SDT is started based on the second information while the terminal is in an RRC inactive state, wherein, while an SDT procedure is ongoing based on the first information, the CG resource for SDT is released upon expiry of the TAT-SDT, and wherein, in case that a response for an initial uplink packet received from the terminal during the SDT procedure is transmitted to the terminal, the ongoing SDT procedure is not terminated and a dynamic grant (DG) is used for the ongoing SDT procedure.
In accordance with another aspect of the disclosure, a terminal is provided. The terminal comprises a transceiver; and a controller configured to: receive, from a base station, a radio resource control (RRC) message including first information configuring a configured grant (CG) resource for small data transmission (SDT) and second information configuring a timing alignment timer (TAT) for SDT (TAT-SDT), start, while the terminal is in an RRC inactive state, the TAT-SDT based on the second information, while an SDT procedure is ongoing based on the first information, release the CG resource for SDT upon expiry of the TAT-SDT, and identify whether a response is received for an initial uplink packet transmitted to the base station during the SDT procedure, wherein, in case that the response is received, the ongoing SDT procedure is not terminated and a dynamic grant (DG) is used for the ongoing SDT procedure.
In accordance with another aspect of the disclosure, a base station is provided. The base station comprises a transceiver; and a controller configured to: transmit, to a terminal, a radio resource control (RRC) message including first information configuring a configured grant (CG) resource for small data transmission (SDT) and second information configuring a timing alignment timer (TAT) for SDT (TAT-SDT), wherein the TAT-SDT is started based on the second information while the terminal is in an RRC inactive state, wherein, while an SDT procedure is ongoing based on the first information, the CG resource for SDT is released upon expiry of the TAT-SDT, and wherein, in case that a response for an initial uplink packet received from the terminal during the SDT procedure is transmitted to the terminal, the ongoing SDT procedure is not terminated and a dynamic grant (DG) is used for the ongoing SDT procedure.
Advantageous Effects of Invention
According to various embodiments of the disclosure, SDT procedure can be efficiently enhanced.
BRIEF DESCRIPTION OF DRAWINGS
The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates an SDT related procedure in accordance with an embodiment of the disclosure.
FIG. 2 illustrates another SDT related procedure in accordance with an embodiment of the disclosure.
FIG. 3 illustrates another SDT related procedure in accordance with an embodiment of the disclosure.
FIG. 4 illustrates a timer handling procedure according to an embodiment of the disclosure.
FIG. 5 illustrates a radio access node (RAN) paging procedure according to an embodiment of the disclosure.
FIG. 6 illustrates another timer handling procedure according to another embodiment of the disclosure.
FIG. 7 illustrates another RAN paging procedure according to another embodiment of the disclosure.
FIG. 8 illustrates another RAN paging procedure according to another embodiment of the disclosure.
FIG. 9 illustrates a radio resource control (RRC) connection resume procedure according to an embodiment of the disclosure.
FIG. 10 illustrates another timer handling procedure according to another embodiment of the disclosure.
FIG. 11 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 12 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 13 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 14 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 15 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 16 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 17 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 18 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 19 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 20 is a block diagram of a terminal according to an embodiment of the disclosure.
FIG. 21 is a block diagram of a base station according to an embodiment of the disclosure.
MODE FOR THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.
It is to be understood that the singular forms âa,â âan,â and âtheâ include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to âa component surfaceâ includes reference to one or more of such surfaces.
By the term âsubstantiallyâ it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.
It is known to those skilled in the art that blocks of a flowchart (or sequence diagram) and a combination of flowcharts may be represented and executed by computer program instructions. These computer program instructions may be loaded on a processor of a general purpose computer, special purpose computer, or programmable data processing equipment. When the loaded program instructions are executed by the processor, they create a means for carrying out functions described in the flowchart. Because the computer program instructions may be stored in a computer readable memory that is us
PRIORITY
This application is a National Phase Entry of PCT International Application No. PCT/KR2022/002921, which was filed on Mar. 2, 2022, and claims priority to Korean Provisional Patent Application No. 10-2021-0029994, which was filed on Mar. 8, 2021, and Korean Patent Application No. 10-2021-0034260, which was filed on Mar. 16, 2021, the entire content of each of which is incorporated herein by reference.
TECHNICAL FIELD
The disclosure relates to a wireless communication system. Specifically, the disclosure relates to an apparatus, a method and a system for handling small data transmission (SDT) related procedures in wireless communication system.
BACKGROUND ART
Considering the development of wireless communication from generation to generation, the technologies have been developed mainly for services targeting humans, such as voice calls, multimedia services, and data services. Following the commercialization of 5G (5th-generation) communication systems, it is expected that the number of connected devices will exponentially grow. Increasingly, these will be connected to communication networks. Examples of connected things may include vehicles, robots, drones, home appliances, displays, smart sensors connected to various infrastructures, construction machines, and factory equipment. Mobile devices are expected to evolve in various form-factors, such as augmented reality glasses, virtual reality headsets, and hologram devices. In order to provide various services by connecting hundreds of billions of devices and things in the 6G (6th-generation) era, there have been ongoing efforts to develop improved 6G communication systems. For these reasons, 6G communication systems are referred to as beyond-5G systems.
6G communication systems, which are expected to be commercialized around 2030, will have a peak data rate of tera (1,000 giga)-level bps and a radio latency less than 100 μsec, and thus will be 50 times as fast as 5G communication systems and have the 1/10 radio latency thereof.
In order to accomplish such a high data rate and an ultra-low latency, it has been considered to implement 6G communication systems in a terahertz band (for example, 95 GHz to 3 THz bands). It is expected that, due to severer path loss and atmospheric absorption in the terahertz bands than those in mmWave bands introduced in 5G, technologies capable of securing the signal transmission distance (that is, coverage) will become more crucial. It is necessary to develop, as major technologies for securing the coverage, radio frequency (RF) elements, antennas, novel waveforms having a better coverage than orthogonal frequency division multiplexing (OFDM), beamforming and massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antennas, and multiantenna transmission technologies such as large-scale antennas. In addition, there has been ongoing discussion on new technologies for improving the coverage of terahertz-band signals, such as metamaterial-based lenses and antennas, orbital angular momentum (OAM), and reconfigurable intelligent surface (RIS).
Moreover, in order to improve the spectral efficiency and the overall network performances, the following technologies have been developed for 6G communication systems: a full-duplex technology for enabling an uplink transmission and a downlink transmission to simultaneously use the same frequency resource at the same time; a network technology for utilizing satellites, high-altitude platform stations (HAPS), and the like in an integrated manner; an improved network structure for supporting mobile base stations and the like and enabling network operation optimization and automation and the like; a dynamic spectrum sharing technology via collision avoidance based on a prediction of spectrum usage; an use of artificial intelligence (AI) in wireless communication for improvement of overall network operation by utilizing AI from a designing phase for developing 6G and internalizing end-to-end AI support functions; and a next-generation distributed computing technology for overcoming the limit of UE computing ability through reachable super-high-performance communication and computing resources (such as mobile edge computing (MEC), clouds, and the like) over the network. In addition, through designing new protocols to be used in 6G communication systems, developing mechanisms for implementing a hardware-based security environment and safe use of data, and developing technologies for maintaining privacy, attempts to strengthen the connectivity between devices, optimize the network, promote softwarization of network entities, and increase the openness of wireless communications are continuing.
It is expected that research and development of 6G communication systems in hyper-connectivity, including person to machine (P2M) as well as machine to machine (M2M), will allow the next hyper-connected experience. Particularly, it is expected that services such as truly immersive extended reality (XR), high-fidelity mobile hologram, and digital replica could be provided through 6G communication systems. In addition, services such as remote surgery for security and reliability enhancement, industrial automation, and emergency response will be provided through the 6G communication system such that the technologies could be applied in various fields such as industry, medical care, automobiles, and home appliances.
Meanwhile, there have been various studies on SDT related procedures for enhanced wireless communication system recently.
The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure.
DISCLOSURE OF INVENTION
Technical Problem
There are needs to enhance SDT procedure for next generation wireless communication system.
Solution to Problem
Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide a communication method and system for converging a sixth generation (6G) and a fifth generation (5G) communication system for supporting higher data rates beyond a fourth generation (4G).
In accordance with an aspect of the disclosure, a method performed by a terminal is provided. The method comprises: receiving, from a base station, a radio resource control (RRC) message including first information configuring a configured grant (CG) resource for small data transmission (SDT) and second information configuring a timing alignment timer (TAT) for SDT (TAT-SDT); starting, while the terminal is in an RRC inactive state, the TAT-SDT based on the second information; while an SDT procedure is ongoing based on the first information, releasing the CG resource for SDT upon expiry of the TAT-SDT; and identifying whether a response is received for an initial uplink packet transmitted to the base station during the SDT procedure, wherein, in case that the response is received, the ongoing SDT procedure is not terminated and a dynamic grant (DG) is used for the ongoing SDT procedure.
In accordance with an aspect of the disclosure, a method performed by a base station is provided. The method comprises: transmitting, to a terminal, a radio resource control (RRC) message including first information configuring a configured grant (CG) resource for small data transmission (SDT) and second information configuring a timing alignment timer (TAT) for SDT (TAT-SDT), wherein the TAT-SDT is started based on the second information while the terminal is in an RRC inactive state, wherein, while an SDT procedure is ongoing based on the first information, the CG resource for SDT is released upon expiry of the TAT-SDT, and wherein, in case that a response for an initial uplink packet received from the terminal during the SDT procedure is transmitted to the terminal, the ongoing SDT procedure is not terminated and a dynamic grant (DG) is used for the ongoing SDT procedure.
In accordance with another aspect of the disclosure, a terminal is provided. The terminal comprises a transceiver; and a controller configured to: receive, from a base station, a radio resource control (RRC) message including first information configuring a configured grant (CG) resource for small data transmission (SDT) and second information configuring a timing alignment timer (TAT) for SDT (TAT-SDT), start, while the terminal is in an RRC inactive state, the TAT-SDT based on the second information, while an SDT procedure is ongoing based on the first information, release the CG resource for SDT upon expiry of the TAT-SDT, and identify whether a response is received for an initial uplink packet transmitted to the base station during the SDT procedure, wherein, in case that the response is received, the ongoing SDT procedure is not terminated and a dynamic grant (DG) is used for the ongoing SDT procedure.
In accordance with another aspect of the disclosure, a base station is provided. The base station comprises a transceiver; and a controller configured to: transmit, to a terminal, a radio resource control (RRC) message including first information configuring a configured grant (CG) resource for small data transmission (SDT) and second information configuring a timing alignment timer (TAT) for SDT (TAT-SDT), wherein the TAT-SDT is started based on the second information while the terminal is in an RRC inactive state, wherein, while an SDT procedure is ongoing based on the first information, the CG resource for SDT is released upon expiry of the TAT-SDT, and wherein, in case that a response for an initial uplink packet received from the terminal during the SDT procedure is transmitted to the terminal, the ongoing SDT procedure is not terminated and a dynamic grant (DG) is used for the ongoing SDT procedure.
Advantageous Effects of Invention
According to various embodiments of the disclosure, SDT procedure can be efficiently enhanced.
BRIEF DESCRIPTION OF DRAWINGS
The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates an SDT related procedure in accordance with an embodiment of the disclosure.
FIG. 2 illustrates another SDT related procedure in accordance with an embodiment of the disclosure.
FIG. 3 illustrates another SDT related procedure in accordance with an embodiment of the disclosure.
FIG. 4 illustrates a timer handling procedure according to an embodiment of the disclosure.
FIG. 5 illustrates a radio access node (RAN) paging procedure according to an embodiment of the disclosure.
FIG. 6 illustrates another timer handling procedure according to another embodiment of the disclosure.
FIG. 7 illustrates another RAN paging procedure according to another embodiment of the disclosure.
FIG. 8 illustrates another RAN paging procedure according to another embodiment of the disclosure.
FIG. 9 illustrates a radio resource control (RRC) connection resume procedure according to an embodiment of the disclosure.
FIG. 10 illustrates another timer handling procedure according to another embodiment of the disclosure.
FIG. 11 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 12 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 13 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 14 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 15 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 16 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 17 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 18 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 19 illustrates another SDT related procedure according to another embodiment of the disclosure.
FIG. 20 is a block diagram of a terminal according to an embodiment of the disclosure.
FIG. 21 is a block diagram of a base station according to an embodiment of the disclosure.
MODE FOR THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.
It is to be understood that the singular forms âa,â âan,â and âtheâ include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to âa component surfaceâ includes reference to one or more of such surfaces.
By the term âsubstantiallyâ it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.
It is known to those skilled in the art that blocks of a flowchart (or sequence diagram) and a combination of flowcharts may be represented and executed by computer program instructions. These computer program instructions may be loaded on a processor of a general purpose computer, special purpose computer, or programmable data processing equipment. When the loaded program instructions are executed by the processor, they create a means for carrying out functions described in the flowchart. Because the computer program instructions may be stored in a computer readable memory that is usable in a specialized computer or a programmable data processing equipment, it is also possible to create articles of manufacture that carry out functions described in the flowchart. Because the computer program instructions may be loaded on a computer or a programmable data processing equipment, when executed as processes, they may carry out operations of functions described in the flowchart.
A block of a flowchart may correspond to a module, a segment, or a code containing one or more executable instructions implementing one or more logical functions, or may correspond to a part thereof. In some cases, functions described by blocks may be executed in an order different from the listed order. For example, two blocks listed in sequence may be executed at the same time or executed in reverse order.
In this description, the words âunitâ, âmoduleâ or the like may refer to a software component or hardware component, such as, for example, a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC) capable of carrying out a function or an operation. However, a âunitâ, or the like, is not limited to hardware or software. A unit, or the like, may be configured so as to reside in an addressable storage medium or to drive one or more processors. Units, or the like, may refer to software components, object-oriented software components, class components, task components, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays or variables. A function provided by a component and unit may be a combination of smaller components and units, and may be combined with others to compose larger components and units. Components and units may be configured to drive a device or one or more processors in a secure multimedia card.
Prior to the detailed description, terms or definitions necessary to understand the disclosure are described. However, these terms should be construed in a non-limiting way.
The âbase stationâ is an entity communicating with a user equipment (UE) and may be referred to as BS, base transceiver station (BTS), node B (NB), evolved NB (eNB), access point (AP), 5G NB (5GNB), or next generation node B (gNB), etc.
The âuser equipmentâ is an entity communicating with a BS and/or another user equipment and may be referred to as UE, device, mobile station (MS), mobile equipment (ME), or terminal.
In the recent years several broadband wireless technologies have been developed to meet the growing number of broadband subscribers and to provide more and better applications and services. The second generation wireless communication system has been developed to provide voice services while ensuring the mobility of users. Third generation wireless communication system supports not only the voice service but also data service. In recent years, the fourth wireless communication system has been developed to provide high-speed data service. However, currently, the fourth generation wireless communication system suffers from lack of resources to meet the growing demand for high speed data services. So fifth generation wireless communication system (also referred as next generation radio or NR) is being developed to meet the growing demand for high speed data services, support ultra-reliability and low latency applications.
The fifth generation wireless communication system supports not only lower frequency bands but also in higher frequency (e.g., mmWave) bands, e.g., 10 GHz to 100 GHz bands, so as to accomplish higher data rates. To mitigate propagation loss of the radio waves and increase the transmission distance, the beamforming, massive Multiple-Input Multiple-Output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are being considered in the design of fifth generation wireless communication system. In addition, the fifth generation wireless communication system is expected to address different use cases having quite different requirements in terms of data rate, latency, reliability, mobility etc. However, it is expected that the design of the air-interface of the fifth generation wireless communication system would be flexible enough to serve the UEs having quite different capabilities depending on the use case and market segment the UE cater service to the end customer. Few example use cases the fifth generation wireless communication system wireless system is expected to address is enhanced Mobile Broadband (eMBB), massive Machine Type Communication (m-MTC), ultra-reliable low latency communication (URLL) etc. The eMBB requirements like tens of Gbps data rate, low latency, high mobility so on and so forth address the market segment representing the conventional wireless broadband subscribers needing internet connectivity everywhere, all the time and on the go. The m-MTC requirements like very high connection density, infrequent data transmission, very long battery life, low mobility address so on and so forth address the market segment representing the Internet of Things (IoT)/Internet of Everything (IoE) envisioning connectivity of billions of devices. The URLL requirements like very low latency, very high reliability and variable mobility so on and so forth address the market segment representing the Industrial automation application, vehicle-to-vehicle/vehicle-to-infrastructure communication foreseen as one of the enabler for autonomous cars.
In the fifth generation wireless communication system operating in higher frequency (e.g., mmWave) bands, UE and gNB communicates with each other using Beamforming. Beamforming techniques are used to mitigate the propagation path losses and to increase the propagation distance for communication at higher frequency band. Beamforming enhances the transmission and reception performance using a high-gain antenna. Beamforming can be classified into Transmission (TX) beamforming performed in a transmitting end and reception (RX) beamforming performed in a receiving end. In general, the TX beamforming increases directivity by allowing an area in which propagation reaches to be densely located in a specific direction by using a plurality of antennas.
In this situation, aggregation of the plurality of antennas can be referred to as an antenna array, and each antenna included in the array can be referred to as an array element. The antenna array can be configured in various forms such as a linear array, a planar array, etc. The use of the TX beamforming results in the increase in the directivity of a signal, thereby increasing a propagation distance. Further, since the signal is almost not transmitted in a direction other than a directivity direction, a signal interference acting on another receiving end is significantly decreased. The receiving end can perform beamforming on a RX signal by using a RX antenna array. The RX beamforming increases the RX signal strength transmitted in a specific direction by allowing propagation to be concentrated in a specific direction, and excludes a signal transmitted in a direction other than the specific direction from the RX signal, thereby providing an effect of blocking an interference signal.
By using beamforming technique, a transmitter can make plurality of transmit beam patterns of different directions. Each of these transmit beam patterns can be also referred as TX beam. Wireless communication system operating at high frequency uses plurality of narrow TX beams to transmit signals in the cell as each narrow TX beam provides coverage to a part of cell. The narrower the TX beam, higher is the antenna gain and hence the larger the propagation distance of signal transmitted using beamforming. A receiver can also make plurality of RX beam patterns of different directions. Each of these receive patterns can be also referred as RX beam.
CA(carrier aggregation)/Multi-connectivity in fifth generation wireless communication system: The fifth generation wireless communication system, supports standalone mode of operation as well dual connectivity (DC). In DC a multiple Rx/Tx UE may be configured to utilize resources provided by two different nodes (or NBs) connected via non-ideal backhaul. One node acts as the Master Node (MN) and the other as the Secondary Node (SN). The MN and SN are connected via a network interface and at least the MN is connected to the core network. NR also supports Multi-RAT Dual Connectivity (MR-DC) operation whereby a UE in radio resource control connected (RRC_CONNECTED) is configured to utilize radio resources provided by two distinct schedulers, located in two different nodes connected via a non-ideal backhaul and providing either E-UTRA (Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access) (i.e. if the node is an ng-eNB) or NR access (i.e. if the node is a gNB). In NR for a UE in RRC_CONNECTED not configured with CA/DC there is only one serving cell comprising of the primary cell. For a UE in RRC_CONNECTED configured with CA/DC the term âserving cellsâ is used to denote the set of cells comprising of the Special Cell(s) and all secondary cells. In NR the term Master Cell Group (MCG) refers to a group of serving cells associated with the Master Node, comprising of the Primary Cell (PCell) and optionally one or more Secondary Cells (SCells). In NR the term Secondary Cell Group (SCG) refers to a group of serving cells associated with the Secondary Node, comprising of the Primary SCG cell (PSCell) and optionally one or more SCells. In NR PCell refers to a serving cell in MCG, operating on the primary frequency, in which the UE either performs the initial connection establishment procedure or initiates the connection reestablishment procedure. In NR for a UE configured with CA, Scell is a cell providing additional radio resources on top of Special Cell. PSCell refers to a serving cell in SCG in which the UE performs random access when performing the Reconfiguration with Sync procedure. For Dual Connectivity operation the term SpCell (i.e. Special Cell) refers to the PCell of the MCG or the PSCell of the SCG, otherwise the term Special Cell refers to the PCell.
System information acquisition in fifth generation wireless communication system: In the fifth generation wireless communication system, node B (gNB) or base station in cell broadcast Synchronization Signal and PBCH block (SSB) consists of primary and secondary synchronization signals (PSS, SSS) and system information. System information includes common parameters needed to communicate in cell. In the fifth generation wireless communication system (also referred as next generation radio or NR), System Information (SI) is divided into the MIB and a number of SIBs where:
the MIB is always transmitted on the BCH with a periodicity of 80 ms and repetitions made within 80 ms and it includes parameters that are needed to acquire SIB1 from the cell. the SIB1 is transmitted on the DL-SCH with a periodicity of 160 ms and variable transmission repetition. The default transmission repetition periodicity of SIB1 is 20 ms but the actual transmission repetition periodicity is up to network implementation. The scheduling information in SIB 1 includes mapping between SIBs and SI messages, periodicity of each SI message and SI window length. The scheduling information in SIB 1 includes an indicator for each SI message, which indicates whether the concerned SI message is being broadcasted or not. If at least one SI message is not being broadcasted, SIB1 may include random access resources (PRACH preamble(s) and PRACH resource(s)) for requesting gNB to broadcast one or more SI message(s). SIBs other than SIB1 are carried in SystemInformation (SI) messages, which are transmitted on the DL-SCH. Only SIBs having the same periodicity can be mapped to the same SI message. Each SI message is transmitted within periodically occurring time domain windows (referred to as SI-windows with same length for all SI messages). Each SI message is associated with a SI-window and the SI-windows of different SI messages do not overlap. That is, within one SI-window only the corresponding SI message is transmitted. Any SIB except SIB1 can be configured to be cell specific or area specific, using an indication in SIB 1. The cell specific SIB is applicable only within a cell that provides the SIB while the area specific SIB is applicable within an area referred to as SI area, which consists of one or several cells and is identified by systemInformationAreaID.
In the fifth generation wireless communication system, Physical Downlink Control Channel (PDCCH) is used to schedule downlink (DL) transmissions on Physical Downlink Shared Channel (PDSCH) and uplink (UL) transmissions on Physical Uplink Shared Channel (PUSCH), where the Downlink Control Information (DCI) on PDCCH includes: Downlink assignments containing at least modulation and coding format, resource allocation, and hybrid automatic repeat request (HARM) information related to downlink shared channel (DL-SCH); Uplink scheduling grants containing at least modulation and coding format, resource allocation, and HARQ information related to uplink shared channel (UL-SCH). In addition to scheduling, PDCCH can be used to for: Activation and deactivation of configured PUSCH transmission with configured grant; Activation and deactivation of PDSCH semi-persistent transmission; Notifying one or more UEs of the slot format; Notifying one or more UEs of the physical resource block(s) (PRB(s)) and orthogonal frequency division multiplexing (OFDM) symbol(s) where the UE may assume no transmission is intended for the UE; Transmission of transmission power control (TPC) commands for Physical Uplink Control Channel (PUCCH) and PUSCH; Transmission of one or more TPC commands for sounding reference signal (SRS) transmissions by one or more UEs; Switching a UE's active bandwidth part; Initiating a random access procedure.
A UE monitors a set of PDCCH candidates in the configured monitoring occasions in one or more configured COntrol REsource SETs (CORESETs) according to the corresponding search space configurations. A CORESET consists of a set of PRBs with a time duration of 1 to 3 OFDM symbols. The resource units Resource Element Groups (REGs) and Control Channel Elements (CCEs) are defined within a CORESET with each CCE consisting a set of REGs. Control channels are formed by aggregation of CCE. Different code rates for the control channels are realized by aggregating different number of CCE. Interleaved and non-interleaved CCE-to-REG mapping are supported in a CORESET. Polar coding is used for PDCCH. Each resource element group carrying PDCCH carries its own demodulation reference signal (DMRS). Quadrature phase shift keying (QPSK) modulation is used for PDCCH.
In fifth generation wireless communication system, a list of search space configurations are signaled by gNB for each configured bandwidth part (BWP) wherein each search configuration is uniquely identified by an identifier. Identifier of search space configuration to be used for specific purpose such as paging reception, SI reception, random access response (RAR) reception is explicitly signaled by gNB. In NR search space configuration comprises of parameters Monitoring-periodicity-PDCCH-slot, Monitoring-offset-PDCCH-slot, Monitoring-symbols-PDCCH-within-slot and duration. A UE determines PDCCH monitoring occasion (s) within a slot using the parameters PDCCH monitoring periodicity (Monitoring-periodicity-PDCCH-slot), the PDCCH monitoring offset (Monitoring-offset-PDCCH-slot), and the PDCCH monitoring pattern (Monitoring-symbols-PDCCH-within-slot). PDCCH monitoring occasions are there in slots âxâ to x+duration where the slot with number âxâ in a radio frame with number âyâ satisfies the equation 1 below:
( y *(number of slots in a radio frame)+ x âMonitoring-offset-PDCCH-slot) mod (Monitoring-periodicity-PDCCH-slot)=0;ââ[Equation 1]
The starting symbol of a PDCCH monitoring occasion in each slot having PDCCH monitoring occasion is given by Monitoring-symbols-PDCCH-within-slot. The length (in symbols) of a PDCCH monitoring occasion is given in the corset associated with the search space. Search space configuration includes the identifier of CORESET configuration associated with it. A list of CORESET configurations are signaled by gNB for each configured BWP wherein each CORESET configuration is uniquely identified by an identifier. Note that each radio frame is of 10 ms duration. Radio frame is identified by a radio frame number or system frame number. Each radio frame comprises of several slots wherein the number of slots in a radio frame and duration of slots depends on sub carrier spacing. The number of slots in a radio frame and duration of slots depends radio frame for each supported subcarrier spacing (SCS) is predefined in NR. Each CORESET configuration is associated with a list of TCI (Transmission configuration indicator) states. One DL reference signal (RS) identifier (ID) (synchronization signal block (SSB) or channel state information reference signal (CSI-RS)) is configured per TCI state. The list of TCI states corresponding to a CORESET configuration is signaled by gNB via RRC signaling. One of the TCI state in TCI state list is activated and indicated to UE by gNB. TCI state indicates the DL TX beam (DL TX beam is quasi-collocated (QCLed) with SSB/CSI RS of TCI state) used by GNB for transmission of PDCCH in the PDCCH monitoring occasions of a search space.
BWP operation in fifth generation wireless communication system: In fifth generation wireless communication system bandwidth adaptation (BA) is supported. With BA, the receive and transmit bandwidth of a UE need not be as large as the bandwidth of the cell and can be adjusted: the width can be ordered to change (e.g. to shrink during period of low activity to save power); the location can move in the frequency domain (e.g. to increase scheduling flexibility); and the subcarrier spacing can be ordered to change (e.g. to allow different services). A subset of the total cell bandwidth of a cell is referred to as a Bandwidth Part (BWP). BA is achieved by configuring RRC connected UE with BWP(s) and telling the UE which of the configured BWPs is currently the active one.
Random access in fifth generation wireless communication system: In the 5G wireless communication system, random access (RA) is supported. Random access (RA) is used to achieve uplink (UL) time synchronization. RA is used during initial access, handover, RRC connection re-establishment procedure, scheduling request transmission, SCG addition/modification, beam failure recovery and data or control information transmission in UL by non-synchronized UE in RRC_CONNECTED state. Several types of random access procedure is supported.
Contention based random access (CBRA): This is also referred as 4 step CBRA. In this type of random access, UE first transmits Random Access preamble (also referred as Msg1) and then waits for Random access response (RAR) in the RAR window. RAR is also referred as Msg2. GNB transmits the RAR on PDSCH. PDCCH scheduling the PDSCH carrying RAR is addressed to RA-radio network temporary identifier (RA-RNTI). RA-RNTI identifies the time-frequency resource (also referred as physical RA channel (PRACH) occasion or PRACH transmission (TX) occasion or RA channel (RACH) occasion) in which RA preamble was detected by gNB. The RA-RNTI is calculated as follows: RA-RNTI=1+s_id+14*t_id+14*80*f_id+14*80*8*ul_carrier_id, where s_id is the index of the first OFDM symbol of the PRACH occasion where UE has transmitted Msg1, i.e. RA preamble; 0â¤s_id<14; t_id is the index of the first slot of the PRACH occasion (0â¤t_id<80); f_id is the index of the PRACH occasion within the slot in the frequency domain (0â¤f_id<8), and ul_carrier_id is the UL carrier used for Msg1 transmission (0 for normal UL (NUL) carrier and 1 for supplementary UL (SUL) carrier. Several RARs for various Random access preambles detected by gNB can be multiplexed in the same RAR media access control (MAC) protocol data unit (PDU) by gNB. An RAR in MAC PDU corresponds to UE's RA preamble transmission if the RAR includes an RA preamble identifier (RAPID) of RA preamble transmitted by the UE. If the RAR corresponding to its RA preamble transmission is not received during the RAR window and UE has not yet transmitted the RA preamble for a configurable (configured by gNB in RACH configuration) number of times, the UE goes back to first step i.e. select random access resource (preamble/RACH occasion) and transmits the RA preamble. A backoff may be applied before going back to first step.
If the RAR corresponding to its RA preamble transmission is received the UE transmits message 3 (Msg3) in UL grant received in RAR. Msg3 includes message such as RRC connection request, RRC connection re-establishment request, RRC handover confirm, scheduling request, SI request etc. It may include the UE identity (i.e. cell-radio network temporary identifier (C-RNTI) or system architecture evolution (SAE)-temporary mobile subscriber identity (S-TMSI) or a random number). After transmitting the Msg3, UE starts a contention resolution timer. While the contention resolution timer is running, if UE receives a PDCCH addressed to C-RNTI included in Msg3, contention resolution is considered successful, contention resolution timer is stopped and RA procedure is completed. While the contention resolution timer is running, if UE receives contention resolution MAC CE including the UE's contention resolution identity (first X bits of common control channel (CCCH) service data unit (SDU) transmitted in Msg3), contention resolution is considered successful, contention resolution timer is stopped and RA procedure is completed. If the contention resolution timer expires and UE has not yet transmitted the RA preamble for a configurable number of times, UE goes back to first step i.e. select random access resource (preamble/RACH occasion) and transmits the RA preamble. A backoff may be applied before going back to first step.
Contention free random access (CFRA): This is also referred as legacy CFRA or 4 step CFRA. CFRA procedure is used for scenarios such as handover where low latency is required, timing advance establishment for Scell, etc. ENB) assigns to UE dedicated Random access preamble. UE transmits the dedicated RA preamble. ENB transmits the RAR on PDSCH addressed to RA-RNTI. RAR conveys RA preamble identifier and timing alignment information. RAR may also include UL grant. RAR is transmitted in RAR window similar to CBRA procedure. CFRA is considered successfully completed after receiving the RAR including RAPID of RA preamble transmitted by the UE. In case RA is initiated for beam failure recovery, CFRA is considered successfully completed if PDCCH addressed to C-RNTI is received in search space for beam failure recovery. If the RAR window expires and RA is not successfully completed and UE has not yet transmitted the RA preamble for a configurable (configured by gNB in RACH configuration) number of times, the UE retransmits the RA preamble.
For certain events such has handover and beam failure recovery if dedicated preamble(s) are assigned to UE, during first step of random access i.e. during random access resource selection for Msg1 transmission UE determines whether to transmit dedicated preamble or non-dedicated preamble. Dedicated preambles is typically provided for a subset of SSBs/CSI RSs. If there is no SSB/CSI RS having DL RSRP above a threshold amongst the SSBs/CSI RSs for which contention free random access resources (i.e. dedicated preambles/ROs) are provided by gNB, UE select non dedicated preamble. Otherwise UE select dedicated preamble. So during the RA procedure, one random access attempt can be CFRA while other random access attempt can be CBRA.
2 step contention based random access (2 step CBRA): In the first step, UE transmits random access preamble on PRACH and a payload (i.e., MAC PDU) on PUSCH. The random access preamble and payload transmission is also referred as MsgA. In the second step, after MsgA transmission, the UE monitors for a response from the network (i.e., gNB) within a configured window. The response is also referred as MsgB. GNB) transmits the MsgB on PDSCH. PDCCH scheduling the PDSCH carrying MsgB is addressed to MsgB-radio network temporary identifier (MSGB-RNTI). MSGB-RNTI identifies the time-frequency resource (also referred as PRACH occasion or PRACH TX occasion or RACH occasion) in which RA preamble was detected by gNB. The MSGB-RNTI is calculated as follows: RA-RNTI=1+s_id+14*t_id+14*80*f_id+14*80*8*ul_carrier_id+14*80*8*2, where s_id is the index of the first OFDM symbol of the PRACH occasion where UE has transmitted Msg1, i.e. RA preamble; 0â¤s_id<14; t_id is the index of the first slot of the PRACH occasion (0â¤t_id<80); fid is the index of the PRACH occasion within the slot in the frequency domain (0â¤f_id<8), and ul_carrier_id is the UL carrier used for Msg1 transmission (0 for NUL carrier and 1 for SUL carrier.
If CCCH SDU was transmitted in MsgA payload, UE performs contention resolution using the contention resolution information in MsgB. The contention resolution is successful if the contention resolution identity received in MsgB matches first 48 bits of CCCH SDU transmitted in MsgA. If C-RNTI was transmitted in MsgA payload, the contention resolution is successful if UE receives PDCCH addressed to C-RNTI. If contention resolution is successful, random access procedure is considered successfully completed. Instead of contention resolution information corresponding to the transmitted MsgA, MsgB may include a fallback information corresponding to the random access preamble transmitted in MsgA. If the fallback information is received, UE transmits Msg3 and performs contention resolution using Msg4 as in CBRA procedure. If contention resolution is successful, random access procedure is considered successfully completed. If contention resolution fails upon fallback (i.e. upon transmitting Msg3), UE retransmits MsgA. If configured window in which UE monitor network response after transmitting MsgA expires and UE has not received MsgB including contention resolution information or fallback information as explained above, UE retransmits MsgA. If the random access procedure is not successfully completed even after transmitting the msgA configurable number of times, UE fallbacks to 4 step RACH procedure i.e. UE only transmits the PRACH preamble.
MsgA payload may include one or more of CCCH SDU, dedicated control channel (DCCH) SDU, dedicated traffic channel (DTCH) SDU, buffer status report (BSR) MAC CE, power headroom report (PHR) MAC CE, SSB information, C-RNTI MAC CE, or padding. MsgA may include UE ID (e.g. random ID, S-TMSI, C-RNTI, resume ID, etc.) along with preamble in first step. The UE ID may be included in the MAC PDU of the MsgA. UE ID such as C-RNTI may be carried in MAC CE wherein MAC CE is included in MAC PDU. Other UE IDs (such random ID, S-TMSI, C-RNTI, resume ID, etc.) may be carried in CCCH SDU. The UE ID can be one of random ID, S-TMSI, C-RNTI, resume ID, IMSI, idle mode ID, inactive mode ID, etc. The UE ID can be different in different scenarios in which UE performs the RA procedure. When UE performs RA after power on (before it is attached to the network), then UE ID is the random ID. When UE perform RA in IDLE state after it is attached to network, the UE ID is S-TMSI. If UE has an assigned C-RNTI (e.g. in connected state), the UE ID is C-RNTI. In case UE is in INACTIVE state, UE ID is resume ID. In addition to UE ID, some addition ctrl information can be sent in MsgA. The control information may be included in the MAC PDU of the MsgA. The control information may include one or more of connection request indication, connection resume request indication, SI request indication, buffer status indication, beam information (e.g. one or more DL TX beam ID(s) or SSB ID(s)), beam failure recovery indication/information, data indicator, cell/BS/TRP switching indication, connection re-establishment indication, reconfiguration complete or handover complete message, etc.
2 step contention free random access (2 step CFRA): In this case gNB assigns to UE dedicated Random access preamble(s) and PUSCH resource(s) for MsgA transmission. RO(s) to be used for preamble transmission may also be indicated. In the first step, UE transmits random access preamble on PRACH and a payload on PUSCH using the contention free random access resources (i.e. dedicated preamble/PUSCH resource/RO). In the second step, after MsgA transmission, the UE monitors for a response from the network (i.e. gNB) within a configured window. The response is also referred as MsgB.
GNB transmits the MsgB on PDSCH. PDCCH scheduling the PDSCH carrying MsgB is addressed to MSGB-RNTI. MSGB-RNTI identifies the time-frequency resource (also referred as PRACH occasion or PRACH TX occasion or RACH occasion) in which RA preamble was detected by gNB. The MSGB-RNTI is calculated as follows: RA-RNTI=1+s_id+14*t_id+14*80*f_id+14*80*8*ul_carrier_id+14*80*8*2, where s_id is the index of the first OFDM symbol of the PRACH occasion where UE has transmitted Msg1, i.e. RA preamble; 0â¤s_id<14; t_id is the index of the first slot of the PRACH occasion (0â¤t_id<80); f_id is the index of the PRACH occasion within the slot in the frequency domain (0â¤f_id<8), and ul_carrier_id is the UL carrier used for Msg1 transmission (0 for NUL carrier and 1 for SUL carrier.
If UE receives PDCCH addressed to C-RNTI, random access procedure is considered successfully completed. If UE receives fallback information corresponding to its transmitted preamble, random access procedure is considered successfully completed.
For certain events such has handover and beam failure recovery if dedicated preamble(s) and PUSCH resource(s) are assigned to UE, during first step of random access i.e. during random access resource selection for MsgA transmission UE determines whether to transmit dedicated preamble or non dedicated preamble. Dedicated preambles is typically provided for a subset of SSB s/CSI RSs. If there is no SSB/CSI RS having DL RSRP above a threshold amongst the SSBs/CSI RSs for which contention free random access resources (i.e. dedicated preambles/ROs/PUSCH resources) are provided by gNB, UE select non dedicated preamble. Otherwise UE select dedicated preamble. So during the RA procedure, one random access attempt can be 2 step CFRA while other random access attempt can be 2 step CBRA.
Upon initiation of random access procedure, UE first selects the carrier (SUL or NUL). If the carrier to use for the Random Access procedure is explicitly signalled by gNB, UE select the signalled carrier for performing Random Access procedure. If the carrier to use for the Random Access procedure is not explicitly signalled by gNB; and if the Serving Cell for the Random Access procedure is configured with supplementary uplink and if the RSRP of the downlink pathloss reference is less than rsrpThresholdSSB-SUL: UE select the SUL carrier for performing Random Access procedure. Otherwise, UE select the NUL carrier for performing Random Access procedure. Upon selecting the UL carrier, UE determines the UL and DL BWP for random access procedure. UE then determines whether to perform 2 step or 4 step RACH for this random access procedure.
If this random access procedure is initiated by PDCCH order and if the raPreambleIndex explicitly provided by PDCCH is not 0b000000, UE selects 4 step RACH. else if 2 step contention free random access resources are signaled by gNB for this random access procedure, UE selects 2 step RACH. else if 4 step contention free random access resources are signaled by gNB for this random access procedure, UE selects 4 step RACH. else if the UL BWP selected for this random access procedure is configured with only 2 step RACH resources, UE selects 2 step RACH. else if the UL BWP selected for this random access procedure is configured with only 4 step RACH resources, UE selects 4 step RACH. else if the UL BWP selected for this random access procedure is configured with both 2 step and 4 step RACH resources, if RSRP of the downlink pathloss reference is below a configured threshold, UE selects 4 step RACH. Otherwise UE selects 2 step RACH.
In the 5th generation (also referred as NR) wireless communication system UE can be in one of the following RRC state: RRC IDLE, RRC INACTIVE and RRC CONNECTED. The RRC states can further be characterized as follows:
In RRC IDLE state, a UE specific discontinuous reception (DRX) may be configured by upper layers (i.e. non-access stratum (NAS)). The UE, monitors Short Messages transmitted with P-RNTI over DCI; Monitors a Paging channel for CN paging using 5G-S-TMSI; âPerforms neighbouring cell measurements and cell (re-)selection; Acquires system information and can send SI request (if configured). In RRC_INACTIVE state, a UE specific DRX may be configured by upper layers or by RRC layer; In this state, UE stores the UE Inactive AS context. A RAN-based notification area is configured by RRC layer. The UE monitors Short Messages transmitted with paging radio network temporary identifier (P-RNTI) over DCI;
Monitors a Paging channel for core network (CN) paging using 5G-system architecture evolution (SAE)-temporary mobile subscriber identity (5G-S-TMSI) and RAN paging using full-RNTI; Performs neighboring cell measurements and cell (re-)selection; Performs radio access node (RAN)-based notification area updates periodically and when moving outside the configured RAN-based notification area; Acquires system information and can send SI request (if configured).
In the RRC_CONNECTED, the UE stores the access stratum (AS) context. Unicast data is transmitted/received to/from UE. At lower layers, the UE may be configured with a UE specific DRX. The UE, monitors Short Messages transmitted with P-RNTI over DCI, if configured; Monitors control channels associated with the shared data channel to determine if data is scheduled for it; Provides channel quality and feedback information; Performs neighboring cell measurements and measurement reporting; Acquires system information.
The 5G or Next Generation Radio Access Network (NG-RAN) based on NR consists of NG-RAN nodes where NG-RAN node is a gNB, providing NR user plane and control plane protocol terminations towards the UE. The gNBs are also connected by means of the NG interfaces to the 5GC, more specifically to the AMF (Access and Mobility Management Function) by means of the NG-C interface and to the UPF (User Plane Function) by means of the NG-U interface. In NR system, the UE may use DRX in RRC_IDLE and RRC_INACTIVE state in order to reduce power consumption. In the RRC_IDLE/RRC_INACTIVE state UE wake ups at regular intervals (i.e. every DRX cycle) for short periods to receive paging, to receive SI update notification and to receive emergency notifications. Paging message is transmitted using PDSCH. PDCCH is addressed to P-RNTI if there is a paging message in PDSCH. P-RNTI is common for all UEs. UE identity (e.g., S-TMSI for RRC_IDLE UE or I-RNTI for RRC_INACTIVE UE) is included in paging message to indicate paging for a specific UE. Paging message may include multiple UE identities to page multiple UEs. Paging message is broadcasted (i.e., PDCCH is masked with P-RNTI) over data channel (e.g., PDSCH). System information (SI) update and emergency notifications are included in DCI and PDCCH carrying this DCI is addressed to P-RNTI. In the RRC idle/inactive mode UE monitors one paging occasion (PO) every DRX cycle. In the RRC idle/inactive mode UE monitors PO in initial DL BWP. In RRC connected state UE monitors one or more POs to receive SI update notification and to receive emergency notifications. In RRC connected state, UE can monitor any PO in paging DRX cycle and monitors at least one PO in SI modification period. In the RRC idle/inactive mode UE monitors PO every DRX cycle in its active DL BWP. A PO is a set of âSâ PDCCH monitoring occasions for paging, where âSâ is the number of transmitted SSBs (i.e. the SSB consists of primary synchronization signal (PSS) and secondary synchronization signal (SSS) and PBCH) in cell. UE first determines the paging frame (PF) and then determines the PO with respect to the determined PF. One PF is a radio frame (10 ms).
The PF for a UE is the radio frame with system frame number âSFNâ which satisfies the equation (SFN+PF_offset) mod T=(T div N)*(UE_ID mod N). Index (i_s), indicating the index of the PO is determined by i_s=floor(UE ID/N) mod Ns. T is DRX cycle of the UE.
In RRC_INACTIVE state, T is determined by the shortest of the UE specific DRX value configured by RRC, UE specific DRX value configured by NAS, and a default DRX value broadcast in system information. In RRC_IDLE state, T is determined by the shortest of UE specific DRX value configured by NAS, and a default DRX value broadcast in system information. If UE specific DRX is not configured by upper layers (i.e. NAS), the default value is applied.
N: number of total paging
CLAIMS
Claims ( 14 )
The invention claimed is:
1. A method performed by a terminal in a wireless communication system, the method comprising:
identifying whether a configured grant-based small data transmission (CG-SDT) timing alignment timer (TAT) expires while a CG-SDT procedure is ongoing;
in case that the CG-SDT TAT expires, identifying whether a physical data control channel (PDCCH) addressed to cell-radio network temporary identity (RNTI) has been received after an initial transmission for the CG-SDT procedure; and
in case that the PDCCH addressed to the C-RNTI has not been received after the initial transmission for the CG-SDT procedure, determining that the ongoing CG-SDT procedure is terminated.
2. The method of claim 1 , wherein an uplink grant for CG-SDT is not used, based on expiry of the CG-SDT TAT, and
wherein the terminal, in a radio resource control (RRC) inactive state, transitions to an RRC idle state, based on the ongoing CG-SDT procedure being terminated.
3. The method of claim 1 , wherein the initial transmission for the CG-SDT procedure is performed with a radio resource control (RRC) resume request message on a common control channel.
4. The method of claim 1 , further comprising:
in case that the PDCCH has not been received after the initial transmission for the CG-SDT procedure, not performing any transmission except a random access preamble and a message A (MSGA) transmission.
5. The method of claim 1 , further comprising:
initiating a random access procedure, based on expiry of the CG-SDT TAT during the ongoing CG-SDT procedure.
6. The method of claim 1 , further comprising:
receiving, from a base station, a radio resource control (RRC) release message including information on a suspend configuration and information on an SDT configuration,
wherein the information on the SDT configuration includes a value of the CG-SDT TAT.
7. The method of claim 6 ,
wherein whether the CG-SDT procedure is triggered is identified based on the SDT configuration.
8. A terminal in a wireless communication system, the terminal comprising:
a transceiver; and
a controller configured to:
identify whether a configured grant-based small data transmission (CG-SDT) timing alignment timer (TAT) expires while a CG-SDT procedure is ongoing,
in case that the CG-SDT TAT expires, identify whether a physical data control channel (PDCCH) addressed to cell-radio network temporary identity (RNTI) has been received after an initial transmission for the CG-SDT procedure, and
in case that the PDCCH addressed to the C-RNTI has not been received after the initial transmission for the CG-SDT procedure, determine that the ongoing CG-SDT procedure is terminated.
9. The terminal of claim 8 , wherein an uplink grant for CG-SDT is not used, based on expiry of the CG-SDT TAT, and
wherein the terminal, in a radio resource control (RRC) inactive state, transitions to an RRC idle state, based on the ongoing CG-SDT procedure being terminated.
10. The terminal of claim 8 , wherein the initial transmission for the CG-SDT procedure is performed with a radio resource control (RRC) resume request message on a common control channel.
11. The terminal of claim 8 , wherein, in case that the PDCCH has not been received after the initial transmission for the CG-SDT procedure, the controller is further configured not to perform any transmission except a random access preamble and a message A (MSGA) transmission.
12. The terminal of claim 8 , wherein the controller is further configured to initiate a random access procedure, based on expiry of the CG-SDT TAT during the ongoing CG-SDT procedure.
13. The terminal of claim 8 , wherein the controller is further configured to control the transceiver to receive, from a base station, a radio resource control (RRC) release message including information on a suspend configuration and information on an SDT configuration, and
wherein the information on the SDT configuration includes a value of the CG-SDT TAT.
14. The terminal of claim 13 , wherein the controller is further configured to identify whether the CG-SDT procedure is triggered based on the SDT configuration.
US18/009,917
2021-03-08
2022-03-02
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Families Citing this family (14)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
WO2022191492A1
( en )
*
2021-03-08
2022-09-15
Samsung Electronics Co., Ltd.
Method and apparatus for handling small data transmission in wireless communication system
EP4064786A1
( en )
*
2021-03-23
2022-09-28
Panasonic Intellectual Property Corporation of America
User equipment and base station involved in transmission of small data
WO2022205434A1
( en )
*
2021-04-02
2022-10-06
Oppo广ä¸ç§»å¨éä¿¡æéå ¬å¸
Channel transmission method, electronic device, and storage medium
US12414075B2
( en )
*
2021-06-21
2025-09-09
Sharp Kabushiki Kaisha
Monitoring paging messages and small data transmission
US20220416990A1
( en )
*
2021-06-24
2022-12-29
FG Innovation Company Limited
Method and device for performing small data transmission
US11910397B2
( en )
*
2021-11-17
2024-02-20
Lenovo (Singapore) Pte. Ltd.
Notification for configured grant-small data transmission action
KR102657934B1
( en )
*
2022-05-11
2024-04-17
주ìíì¬ ë¸ëí
Method and Apparatus for uplink transmission in RRC_INACTIVE state
KR102657930B1
( en )
*
2022-05-11
2024-04-17
주ìíì¬ ë¸ëí
Method and Apparatus for uplink transmission in RRC_INACTIVE state
US20230397090A1
( en )
*
2022-06-02
2023-12-07
Qualcomm Incorporated
Targeted si update indication
EP4648502A1
( en )
*
2023-01-03
2025-11-12
LG Electronics Inc.
Parameter determination method for positioning in wireless communication system, and device therefor
WO2024154977A1
( en )
*
2023-01-18
2024-07-25
Lg Electronics Inc.
Method and apparatus for performing mobile terminated small data transmission based on configured grant in wireless communication system
US20240323926A1
( en )
*
2023-03-22
2024-09-26
Samsung Electronics Co., Ltd.
Small data transmission
US12543081B2
( en )
*
2023-03-28
2026-02-03
Qualcomm Incorporated
Techniques for configuring an initial uplink transmission after a cell switch
CN121218387A
( en )
*
2024-06-25
2025-12-26
å¤æ®æ ªå¼ä¼ç¤¾
User equipment, base stations and methods
Citations (12)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US8724568B2
( en )
2009-03-13
2014-05-13
Lg Electronics Inc.
Method of handling an uplink synchronization timer during a handover in wireless communication system
US9565703B2
( en )
2009-01-08
2017-02-07
Lg Electronics Inc.
Method of handling time alignment command during a random access procedure
US20200170069A1
( en )
*
2018-11-27
2020-05-28
Asustek Computer Inc.
Method and apparatus for releasing preconfigured uplink resources configuration in a wireless communication system
WO2021031112A1
( en )
2019-08-20
2021-02-25
Qualcomm Incorporated
Paging for mobile-terminated small data reception in idle and/or inactive mode
US20210144742A1
( en )
*
2019-11-07
2021-05-13
Hyoungsuk Jeon
Power Control for a Two-Step Random Access Procedure
US20210337625A1
( en )
*
2020-04-23
2021-10-28
FG Innovation Company Limited
Small data transmission in radio resource control (rrc) inactive state
US20210410180A1
( en )
*
2020-06-24
2021-12-30
FG Innovation Company Limited
User equipment and method for small data transmission
WO2022079692A1
( en )
*
2020-10-15
2022-04-21
Lenovo (Singapore) Pte. Ltd.
Random access procedure in a non-terrestrial network
US20220132277A1
( en )
*
2020-10-22
2022-04-28
Samsung Electronics Co., Ltd.
Methods and systems for energy efficient and synchronized reception of mbs in 5g communication network
US20220232641A1
( en )
*
2021-01-18
2022-07-21
Lg Electronics Inc.
Method and apparatus for transmitting/receiving wireless signal in wireless communication system
US20230224997A1
( en )
*
2021-03-08
2023-07-13
Samsung Electronics Co., Ltd
Method and apparatus for handling small data transmission in wireless communication system
US20230319895A1
( en )
*
2008-08-11
2023-10-05
Equo Ip Llc
Timing alignment procedure for a user equipment
2022
2022-03-02
WO
PCT/KR2022/002921
patent/WO2022191492A1/en
not_active
Ceased
2022-03-02
KR
KR1020237029739A
patent/KR20230135677A/en
active
Pending
2022-03-02
EP
EP22767388.6A
patent/EP4151032A4/en
active
Pending
2022-03-02
US
US18/009,917
patent/US12452948B2/en
active
Active
2025
2025-09-25
US
US19/340,005
patent/US20260025877A1/en
active
Pending
Patent Citations (13)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US20230319895A1
( en )
*
2008-08-11
2023-10-05
Equo Ip Llc
Timing alignment procedure for a user equipment
US9565703B2
( en )
2009-01-08
2017-02-07
Lg Electronics Inc.
Method of handling time alignment command during a random access procedure
US9900914B2
( en )
2009-01-08
2018-02-20
Lg Electronics Inc.
Method of handling time alignment command during a random access procedure
US8724568B2
( en )
2009-03-13
2014-05-13
Lg Electronics Inc.
Method of handling an uplink synchronization timer during a handover in wireless communication system
US20200170069A1
( en )
*
2018-11-27
2020-05-28
Asustek Computer Inc.
Method and apparatus for releasing preconfigured uplink resources configuration in a wireless communication system
WO2021031112A1
( en )
2019-08-20
2021-02-25
Qualcomm Incorporated
Paging for mobile-terminated small data reception in idle and/or inactive mode
US20210144742A1
( en )
*
2019-11-07
2021-05-13
Hyoungsuk Jeon
Power Control for a Two-Step Random Access Procedure
US20210337625A1
( en )
*
2020-04-23
2021-10-28
FG Innovation Company Limited
Small data transmission in radio resource control (rrc) inactive state
US20210410180A1
( en )
*
2020-06-24
2021-12-30
FG Innovation Company Limited
User equipment and method for small data transmission
WO2022079692A1
( en )
*
2020-10-15
2022-04-21
Lenovo (Singapore) Pte. Ltd.
Random access procedure in a non-terrestrial network
US20220132277A1
( en )
*
2020-10-22
2022-04-28
Samsung Electronics Co., Ltd.
Methods and systems for energy efficient and synchronized reception of mbs in 5g communication network
US20220232641A1
( en )
*
2021-01-18
2022-07-21
Lg Electronics Inc.
Method and apparatus for transmitting/receiving wireless signal in wireless communication system
US20230224997A1
( en )
*
2021-03-08
2023-07-13
Samsung Electronics Co., Ltd
Method and apparatus for handling small data transmission in wireless communication system
Non-Patent Citations (12)
* Cited by examiner, â Cited by third party
Title
3GPP TS 38.321 V16.3.0, (Dec. 2020), pp. 154.
Apple, " Subsequent data transmission for SDT ", R2-2101368, 3GPP TSG-RAN WG2 Meeting #113-e, E-meeting, Jan. 15, 2021, pp. 5.
Ericsson, " Details of CG Based SDT ", R2-2009964, 3GPP TSG-RAN WG2 #112e, Nov. 2-13, 2020, 4 pages.
European Search Report dated Jul. 25, 2025 issued in counterpart application No. 22767388.6-1206, 13 pages.
European Search Report dated Sep. 29, 2023 issued in counterpart application No. 22767388.6-1216, 13 pages.
Huawei et al., " Small data transmission with CG-based scheme ", R2-2101213, 3GPP TSG-RAN WG2 #113-e, E-meeting, Jan. 15, 2021, pp. 11.
Korean Office Action dated Aug. 26, 2025 issued in counterpart application No. 10-2023-7029739, 13 pages.
Lenovo, " Report from email discussion [POST112-e][550][SDT] Further details of CG aspects ", R2-2100930, 3GPP RAN WG2 Meeting #113e, E-meeting, Jan. 14, 2021, pp. 33.
PCT/ISA/210 Search Report issued on PCT/KR2022/002921, Jun. 13, 2022, pp. 3.
PCT/ISA/237 Written Opinion issued on PCT/KR2022/002921, Jun. 13, 2022, pp. 4.
Session Chair (InterDigital), Report for Rel-17 Small Data and URLLC/IIoT and Rel-16 NR-U, Power Savings, and 2step RACH, R2-2101954, 3GPP TSG-RAN WG2 Meeting #113 Electronic, Jan. 25-Feb. 5, 2021, 25 pages.
ZTE Corporation et al., " Configured grant based small data transmission ", R2-2101158, 3GPP TSGRAN WG2 #113e, eMeeting, Jan. 14, 2021, pp. 9.
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