Restricted random access process

Abstract

An apparatus, method, and computer program product are provided for initiating a small data transmission procedure, receiving information related to a restriction on performing a random access procedure during the small data transmission procedure, and restricting the random access procedure based on the information related to the restriction.

Description

Technical Field

[0001] The present application relates generally to limiting random access procedures and more particularly to limiting random access procedures during small data transmission procedures. Background Art

[0002] Due to the increase in the consumption content and complexity of communication networks, different methods for effectively utilizing network resources are studied. Summary of the Invention

[0003] Various aspects of the present invention are set out in the claims. The scope of protection sought by various embodiments of the present invention is given by the independent claims. Examples and features described in this specification that do not fall within the scope of the independent claims (if any) are to be construed as examples useful for understanding various embodiments of the present invention.

[0004] According to a first aspect of the present invention, there is provided an apparatus comprising means for initiating a small data transmission procedure, receiving information related to restriction of performing a random access procedure during the small data transmission procedure, and restricting the random access procedure based on the information related to the restriction.

[0005] According to a second aspect of the present invention, there is provided a method comprising: initiating a small data transmission procedure, receiving information related to restriction of performing a random access procedure during the small data transmission procedure, and restricting the random access procedure based on the information related to the restriction.

[0006] According to a third aspect of the present invention, there is provided a computer program comprising instructions for causing an apparatus to at least perform the following operations: initiating a small data transmission procedure, receiving information related to restrictions on performing a random access procedure during the small data transmission procedure, and restricting the random access procedure based on the information related to the restrictions.

[0007] According to a fourth aspect of the present invention, a device is provided, comprising at least one processor and at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, enable the device to at least: initiate a small data transmission procedure, receive information related to restrictions on performing a random access procedure during the small data transmission procedure, and restrict the random access procedure based on the information related to the restrictions.

[0008] According to a fifth aspect of the present invention, a non-transitory computer-readable medium is provided, which includes program instructions for causing an apparatus to perform at least the following processes: initiating a small data transmission process, receiving information related to restrictions on performing a random access process during the small data transmission process, and restricting the random access process based on the information related to the restrictions.

[0009] According to a sixth aspect of the present invention, a computer-readable medium comprising program instructions is provided, wherein the program instructions are used to cause a device to perform at least the following processes: initiating a small data transmission process, receiving information related to restrictions on performing a random access process during the small data transmission process, and restricting the random access process based on the information related to the restrictions.

[0010] According to a seventh aspect of the present invention, there is provided an apparatus comprising means for receiving an indication of a small data transmission procedure and transmitting information related to restrictions on performing a random access procedure during the small data transmission procedure based on the indication.

[0011] According to an eighth aspect of the present invention, there is provided a method comprising: receiving an indication of a small data transmission procedure, and transmitting information related to restrictions on performing a random access procedure during the small data transmission procedure based on the indication.

[0012] According to a ninth aspect of the present invention, there is provided a computer program comprising instructions for causing an apparatus to at least perform the following operations: receive an indication of a small data transmission procedure, and transmit information related to restrictions on performing a random access procedure during the small data transmission procedure based on the indication.

[0013] According to a tenth aspect of the present invention, a device is provided, which includes at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, enable the device to at least: receive an indication of a small data transmission process, and transmit information related to restrictions on performing a random access process during the small data transmission process based on the indication.

[0014] According to the eleventh aspect of the present invention, a non-transitory computer-readable medium is provided, which includes program instructions for causing an apparatus to perform at least the following processes: receiving an indication of a small data transmission process, and transmitting information related to restrictions on performing a random access process during the small data transmission process based on the indication.

[0015] According to a twelfth aspect of the present invention, a computer-readable medium is provided, which includes program instructions for causing an apparatus to perform at least the following processes: receiving an indication of a small data transmission process, and transmitting information related to restrictions on performing a random access process during the small data transmission process based on the indication. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For a more complete understanding of example embodiments of the present invention, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0017] Figure 1shows a portion of an exemplary radio access network in which examples of the disclosed embodiments may be applied;

[0018] Figure 2 A block diagram illustrating an example apparatus in which examples of the disclosed embodiments may be applied;

[0019] Figure 3 illustrates an example method incorporating example aspects of the present invention;

[0020] Figure 4 illustrates another example method incorporating example aspects of the present invention; and

[0021] Figure 5 An example signaling diagram incorporating aspects of examples of the present invention is illustrated. DETAILED DESCRIPTION

[0022] The following embodiments are illustrative. Although the specification may refer to "an," "one," or "some" embodiments at several points in the text, this does not necessarily mean that each reference refers to the same embodiment or that a particular feature applies only to a single embodiment. Individual features of different embodiments may also be combined to provide other embodiments.

[0023] Example embodiments relate to limiting random access procedures of terminal devices during small data transmission procedures.

[0024] According to an example embodiment, an apparatus such as a terminal device is configured to initiate a small data transmission procedure, receive information related to restrictions on performing a random access procedure during the small data transmission procedure, restrict the random access procedure based on the information related to the restrictions, and enable initiation of a random access procedure to perform the random access procedure after the restrictions are terminated.

[0025] According to another example embodiment, another apparatus, such as a radio access network, is configured to receive an indication of a small data transmission procedure, transmit information related to restrictions on performing a random access procedure during the small data transmission procedure based on the indication, and configure an uplink grant for the random access procedure simultaneously with the small data transmission procedure.

[0026] In the following, different exemplary embodiments will be described using radio access architectures based on Long Term Evolution Advanced (LTE-Advanced, LTE-A) or New Radio (NR, 5G) as examples of access architectures to which the embodiments may be applied, without, however, limiting the embodiments to such architectures. It will be apparent to a person skilled in the art that these embodiments may also be applied to other types of communication networks having suitable components by appropriately adjusting parameters and procedures. Some examples of suitable other options are Universal Mobile Telecommunications System (UMTS) Radio Access Network (UTRAN or E-UTRAN), Long Term Evolution (LTE, essentially the same as E-UTRA), Wireless Local Area Network (WLAN or WiFi), Worldwide Interoperability for Microwave Access (WiMax), Personal Communications Service (PCS), Wideband Code Division Multiple Access (WCDMA), systems using Ultra-Wideband (UWB) technology, sensor networks, Mobile Ad Hoc Networks (MANETs), and Internet Protocol Multimedia Subsystem (IMS), or any combination thereof.

[0027] Figure 1 Depicted are examples of simplified system architectures showing some elements and functional entities, which are logical units, the implementation of which may differ from what is shown. Figure 1 The connections shown are logical connections; the actual physical connections may be different. It will be apparent to those skilled in the art that the system typically includes, in addition to Figure 1 Other functions and structures than those shown.

[0028] However, the embodiments are not limited to the systems given as examples, but a person skilled in the art may apply the solution to other communication systems having the necessary characteristics.

[0029] Figure 1 The example of FIG. 1 shows a portion of an exemplary radio access network.

[0030] Figure 1 Shown are user devices 100 and 102 configured to wirelessly connect to an access node (e.g., (e / g) NodeB) 104 providing the cell over one or more communication channels in the cell. The physical link from the user device to the (e / g) NodeB is referred to as an uplink or reverse link, while the physical link from the (e / g) NodeB to the user device is referred to as a downlink or forward link. It should be understood that the (e / g) NodeBs or their functions can be implemented using any node, host, server, access point, or other entity suitable for such use.

[0031] A communication system typically includes more than one (e / g)NodeB, in which case the (e / g)NodeBs may also be configured to communicate with each other via wired or wireless links designed for this purpose. These links may be used not only for signaling purposes, but also for routing data from one (e / g)NodeB to another. A (e / g)NodeB is a computing device configured to control the radio resources of the communication system to which it is coupled. A NodeB may also be referred to as a base station, an access point, an access node, or any other type of interface device including a relay station capable of operating in a wireless environment. The (e / g)NodeB includes or is coupled to a transceiver. From the transceiver of the (e / g)NodeB, a connection to an antenna unit is provided, which establishes a bidirectional radio link to the user equipment. The antenna unit may include multiple antennas or antenna elements. The (e / g)NodeB is also connected to a core network 110 (CN or Next Generation Core NGC). Depending on the system, the counterpart on the CN side can be a serving gateway (S-GW, routing and forwarding user data packets), a packet data network gateway (P-GW) for providing connectivity of user equipment (UE) to external packet data networks, or a mobility management entity (MME), etc.

[0032] A user equipment (also referred to as a UE, user device, user terminal, terminal device, etc.) illustrates a type of apparatus to which resources on the air interface are allocated and assigned, and therefore any features described herein using a user equipment may be implemented using a corresponding apparatus such as a relay node. An example of such a relay node is a layer 3 relay (self-backhaul relay) toward a base station.

[0033] A user device generally refers to a portable computing device, including wireless mobile communication devices, that operate with or without a subscriber identity module (SIM). These devices include, but are not limited to, the following types of devices: mobile stations (mobile phones), smartphones, personal digital assistants (PDAs), handheld devices (handsets), devices using wireless modems (such as alarms or measurement devices), laptop computers and / or touchscreen computers, tablet computers, game consoles, notebook computers, and multimedia devices. It should be understood that a user device can also be an exclusively or nearly exclusively uplink-only device, an example of which is a camera or camcorder that uploads images or video clips to a network. A terminal device can also be a device capable of operating in an Internet of Things (IoT) network, in which objects are provided with the ability to transmit data over a network without human-to-human or human-to-computer interaction. User devices can also utilize the cloud. In some applications, a user device can include a small portable device with a radio (such as a watch, headphones, or glasses), with computing performed in the cloud. A user device (or, in some embodiments, a layer 3 relay node) is configured to perform one or more user device functions. A user device may also be called a subscriber unit, mobile station, remote terminal, access terminal, user terminal, or user equipment (UE), to mention just a few names or devices.

[0034] Wireless device is a general term covering both access nodes and terminal devices.

[0035] The various techniques described herein can also be applied to cyber-physical systems (CPS)—systems of computing elements that collaborate to control physical entities. CPS can implement and utilize a large number of interconnected ICT devices (sensors, actuators, processors, microcontrollers, etc.) embedded in different locations within a physical object. Mobile cyber-physical systems, in which the physical systems discussed have inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals.

[0036] Additionally, although the apparatus is depicted as a single entity, different units, processors and / or memory units may be implemented. Figure 1 Not all are shown).

[0037] 5G supports the use of multiple-input multiple-output (MIMO) antennas, many more base stations or nodes than LTE (the so-called small cell concept), including macro sites that collaborate with smaller base stations and adopt multiple radio technologies, depending on service requirements, use cases and / or available spectrum. 5G mobile communications support a wide range of use cases and related applications, including video streaming, augmented reality, different data sharing methods and various forms of machine-type applications (such as (massive) machine-type communications (mMTC), including vehicle safety, different sensors and real-time control). 5G is expected to have multiple radio interfaces, namely sub-6 GHz, cmWave and mmWave, and be integrable with existing conventional radio access technologies such as LTE. Integration with LTE can be implemented, at least in the early stages, as a system in which macro coverage is provided by LTE and 5G radio interface access comes from small cells by aggregation to LTE. In other words, 5G is planned to support both inter-RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as sub-6 GHz-cmWave, sub-6 GHz-cmWave-mmWave). One of the concepts being considered for use in 5G networks is network slicing, in which multiple independent and dedicated virtual subnets (network instances) can be created within the same infrastructure to run services with different requirements for latency, reliability, throughput, and mobility.

[0038] The current architecture in LTE networks is fully distributed in the radio and fully centralized in the core network. Low-latency applications and services in 5G may require content to be close to the radio, which may lead to local breakout and multi-access edge computing (MEC). 5G enables analysis and knowledge generation to be performed at the data source. This approach requires leveraging resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content close to cellular subscribers to speed up response times. Edge computing covers a wide range of technologies, such as wireless sensor networks, mobile data collection, mobile signature analysis, collaborative distributed peer-to-peer self-organizing networks and processing (also categorized as local cloud / fog computing and grid / mesh computing), dew computing, mobile edge computing, cloudlets, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, the Internet of Things (massive connectivity and / or latency-critical), and critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, and healthcare applications).

[0039] The communication system may also be capable of communicating with other networks (such as the public switched telephone network or the Internet 112) and / or utilizing services provided by them. The communication network may also be capable of supporting the use of cloud services, for example, at least a portion of the core network operations may be provided as a cloud service (this is in the context of Figure 1 The communication system may also include a central control entity or the like that provides facilities for networks of different operators to cooperate, for example, in spectrum sharing.

[0040] Edge cloud can be introduced into the radio access network (RAN) by leveraging network function virtualization (NFV) and software defined networking (SDN). The use of edge cloud can mean that access node operations will be performed at least partially in a server, host or node that is operatively coupled to a remote radio head or base station including the radio portion. Node operations can also be distributed among multiple servers, nodes or hosts. The application of cloudRAN architecture enables RAN real-time functions to be performed on the RAN side (in the distributed unit DU 104) and non-real-time functions to be performed in a centralized manner (in the centralized unit CU 108).

[0041] It should also be understood that the distribution of work between core network operations and base station operations may be different from that of LTE, or even non-existent. Some other technologies that may be used include, for example, big data and all-IP, which may change the way networks are built and managed. 5G (or New Radio (NR)) networks are designed to support multiple hierarchical structures, in which MEC servers can be placed between the core and base stations or nodeBs (gNBs). It should be understood that MEC can also be applied to 4G networks.

[0042] 5G can also leverage satellite communications to enhance or supplement the coverage of 5G services, for example by providing backhaul. Possible use cases are providing service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for passengers on board, or ensuring service availability for critical communications and future rail, maritime, and / or aviation communications. Satellite communications can leverage geostationary Earth orbit (GEO) satellite systems as well as low Earth orbit (LEO) satellite systems, particularly mega-constellations (systems in which hundreds of (nano)satellites are deployed). Each satellite 106 in a mega-constellation can cover several satellite-enabled network entities, creating a terrestrial cell. A terrestrial cell can be created by a terrestrial relay node 104 or a gNB located on the ground or in a satellite.

[0043] It will be apparent to those skilled in the art that the described system is merely an example of a portion of a radio access system, and that in practice, the system may include multiple (e / g)NodeBs, user equipment may access multiple radio cells, and the system may also include other devices, such as physical layer relay nodes or other network elements. At least one of the (e / g)NodeBs may be a home (e / g)NodeB. Furthermore, within a geographical area of ​​the radio communication system, multiple different types of radio cells and multiple radio cells may be provided. A radio cell may be a macro cell (or umbrella cell), which is a large cell typically tens of kilometers in diameter, or a smaller cell such as a micro cell, a femto cell, or a pico cell. Figure 1 An (e / g)NodeB can provide any of these cells. A cellular radio system can be implemented as a multi-layer network comprising several types of cells. In some exemplary embodiments, in a multi-layer network, one access node provides one or more cells, and therefore multiple (e / g)NodeBs are required to provide such a network structure.

[0044] In order to meet the needs of improving the deployment and performance of communication systems, the concept of "plug and play" (e / g) NodeB has been introduced. Generally, a network that can use "plug and play" (e / g) NodeB includes not only the home (e / g) NodeB (H(e / g)nodeB) but also the home nodeB gateway or HNB-GW ( Figure 1 Typically, an HNB gateway (HNB-GW) installed in an operator's network can aggregate services from a large number of HNBs back to the core network.

[0045] As is well known in connection with wireless communication systems, control information or management information is transmitted via a radio interface, for example between the terminal device 100 and the access node 104 .

[0046] In order to communicate with the RAN, the terminal device may need to perform a synchronization process with the RAN to determine the timing of transmission and reception. The synchronization of the terminal device for transmission may be referred to as uplink synchronization, while the synchronization of the terminal device for reception may be referred to as downlink synchronization.

[0047] In other words, uplink synchronization involves the process by which a terminal device determines the precise timing based on which it can send uplink data. A RAN typically handles multiple terminal devices, and the RAN needs to ensure that uplink signals from multiple terminal devices are aligned with a common reception time at the RAN. In some cases, the RAN may need to use the Radio Resource Control (RRC) protocol or the Medium Access Control (MAC) protocol to adjust the transmission timing of the terminal device. The process of acquiring uplink synchronization may be referred to as a Random Access (RA) procedure.

[0048] There may be situations where relatively small amounts of data need to be transmitted from a terminal device to a radio access network (RAN). For example, various Internet of Things (IoT) applications may involve exchanging small amounts of data such as metering, alarm, and / or notification data.

[0049] The terminal device may be configured to perform a Small Data Transfer (SDT) procedure for transmitting a small amount of data. The SDT procedure may include transmitting data while the terminal device is in an inactive state. For example, the SDT procedure may enable data to be transmitted without requiring an RRC connection establishment procedure.

[0050] However, while the SDT procedure is in progress, new data packets may enter the terminal device's buffer, and the terminal device may trigger a buffer status report (BSR) and attempt to send a BSR to inform the RAN about the amount of data in the uplink buffer available for transmission to the RAN. If there are no resources available to transmit the BSR and / or buffer data to the RAN, the BSR may trigger an RA procedure to request uplink resources / grants. This consumes resources and may cause some delay as the terminal device needs to evaluate the appropriate beam to attempt the RA procedure.

[0051] Figure 2 An exemplary apparatus is shown in the example of FIG.

[0052] Figure 2 2 is a block diagram illustrating an apparatus 200 operating according to an exemplary embodiment of the present invention. The apparatus 200 may be, for example, an electronic device such as a chip, a chipset, a wireless access network, or a terminal device. Figure 2 In the example of FIG, the apparatus 200 is a terminal device configured to communicate with a radio access network (RAN) 250. The apparatus 200 includes a processor 210 and a memory 260. In other examples, the apparatus 200 may include multiple processors.

[0053] exist Figure 2In the example of the present invention, the processor 210 is a control unit operatively connected to read from and write to the memory 260. The processor 210 may also be configured to receive control signals received via the input interface and / or the processor 210 may be configured to output control signals via the output interface. In an example embodiment, the processor 210 may be configured to convert the received control signals into appropriate commands for controlling the functions of the device.

[0054] The memory 260 stores computer program instructions 220 that, when loaded into the processor 210, control the operation of the apparatus 200, as described below. In other examples, the apparatus 200 may include more than one memory 260 or different kinds of storage devices.

[0055] The computer program instructions 220 for enabling the implementation of the exemplary embodiments of the present invention, or a portion of such computer program instructions, may be loaded onto the apparatus 200 by the manufacturer of the apparatus 200, by a user of the apparatus 200, or by the apparatus 200 itself based on a download procedure, or the instructions may be pushed to the apparatus 200 by an external device. The computer program instructions may arrive at the apparatus 200 via an electromagnetic carrier signal, or may be copied from a physical entity such as a computer program product, or a storage device or recording medium such as a compact disc (CD), a compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), or a Blu-ray disc.

[0056] According to an example embodiment, the apparatus 200 includes a terminal device. For example, the apparatus 200 may include a user device such as a smart phone, a tablet computer, or the like.

[0057] According to an example embodiment, the apparatus 200 is configured to communicate with an access node, such as the RAN 250. Communicating with the RAN 250 may include, for example, receiving configuration information from the RAN 250, establishing a communication link with the RAN 250, receiving one or more data packets from the RAN 250, transmitting one or more data packets or requests to the RAN 250, and the like.

[0058] Communication between the apparatus 200 and the RAN 250 may need to be organized in a controlled manner. Radio Resource Control (RRC) is a protocol that includes functions related to communication between a terminal device and the RAN. For example, RRC includes connection establishment and release functions, broadcasting of system information (SI), and establishment, reconfiguration, and release of radio bearers between the terminal device and the RAN.

[0059] The operation of the RRC is guided by a state machine that defines specific states of the terminal device. RRC states include a connected state such as RRC_CONNECTED in the 3GPP specification, an inactive state such as RRC_INACTIVE in the 3GPP specification, and an idle state such as RRC_IDLE in the 3GPP specification. In different states, the terminal device has different amounts of available radio resources. The terminal is also configured to switch from a first state to a second state in response to receiving a command from the network.

[0060] According to an example embodiment, apparatus 200 is configured to initiate a small data transmission (SDT) procedure. According to an example embodiment, the small data transmission includes a small data transmission using uplink resources. In some examples, the uplink resources may include random access channel (RACH) resources, such as MSGA resources on a 2-step RACH or Msg3 resources on a 4-step RACH. In some examples, the uplink resources may include configured grant (CG) resources configured for apparatus 200.

[0061] Initiating the small data transfer may include, for example, transmitting an indication of the small data transfer procedure to the RAN 250. The apparatus 200 may be configured to initiate the SDT procedure in response to receiving one or more data packets in a data buffer of the apparatus 200.

[0062] According to an example embodiment, the small data transfer procedure includes transmitting data in an inactive state of the apparatus 200. For example, the apparatus 200 may be configured to perform the SDT procedure without state transition to a connected state such as RRC_CONNECTED of the 3GPP specification.

[0063] Without limiting the scope of the claims, an advantage of small data transmission is that data can be transmitted when the device is not active, thereby reducing power consumption of the device.

[0064] The SDT process may include a random access (RA) procedure for acquiring uplink synchronization and a radio resource control (RRC) connection. The RA process may be initiated by the terminal device by sending a RACH signal to the RAN. The RACH signal may be referred to as a RACH preamble. The preamble corresponds to a specific physical random access channel (PRACH).

[0065] The RA procedure may include, for example, contention-based random access (CBRA) or contention-free random access (CFRA) of the 3GPP specification. The RA procedure associated with the SDT procedure may be referred to as a first random access procedure. When performing CBRA, the apparatus 200 is configured to randomly select a preamble from a preamble pool shared with multiple terminal devices. In the event that the same preamble is selected by another device, the RAN 250 is configured to handle the contention using a contention resolution mechanism. When performing CFRA, the apparatus 200 is configured to receive a preamble from the RAN 250, so that there should be no preamble collision.

[0066] According to an example embodiment, the apparatus 200 is configured to receive information related to restrictions on performing a random access procedure during a small data transmission procedure. The RA procedure may include an RA procedure different from the RA procedure associated with the SDT procedure and may be referred to as a second random access procedure. The second random access procedure may include, for example, an RA procedure subsequent to the first random access procedure.

[0067] The information related to the restriction on performing the random access procedure may include instructions, parameter values ​​and / or one or more criteria for applying the restriction.

[0068] According to an example embodiment, the information related to the restriction of performing the random access procedure includes an instruction for restricting the initiation of the random access procedure. For example, the information related to performing the RA procedure may include an instruction for restricting or preventing the initiation of the second RA procedure.

[0069] According to an example embodiment, the information related to the restriction of performing a random access procedure includes information related to the timing of the restriction. For example, the information related to the timing of the restriction may include a time period, a specific time instance, or a duration of the restriction. The information related to the timing of the restriction may include information indicating when the restriction is effective or ineffective.

[0070] The timing of the restriction may include a defined start time and a defined end time; or may include a defined start time such that the end time is defined based on a condition or criteria.

[0071] According to an example embodiment, the information related to the restriction of performing the random access procedure includes a time period for restricting the initiation of the random access procedure. The time period may include a time period from a first time to a second time.

[0072] The time period may involve performing a random access procedure associated with the SDT procedure. For example, the time period may include a time period for performing the first random access procedure or a time period for completing the first random access procedure.

[0073] As another example, the time period may relate to performing the SDT process.For example, the time period may include a specified time period, such as the duration of the SDT process or a time period for completing the SDT process.

[0074] According to an example embodiment, the information related to the restriction on performing the random access procedure includes a time when the apparatus 200 is allowed to initiate the random access procedure.

[0075] According to an example embodiment, the information related to the restriction of performing the random access procedure includes a timer and a trigger condition for starting the timer. The device 200 can be configured to apply the restriction to perform the RA procedure when the timer is activated and / or running. For example, the device 200 can be configured to apply the restriction until the timer expires. For example, the device 200 can be configured to apply the restriction to perform the RA procedure even if a buffer status report and a subsequent scheduling request (SR) are triggered after new data arrives. According to an example embodiment, the scheduling request includes a request for allocating uplink resources, which are used to transmit one or more data packets.

[0076] According to an example embodiment, the triggering condition includes at least one of: completion of contention resolution of a random access procedure associated with the small data transmission procedure, completion of a random access procedure associated with the small data transmission procedure, reception of an uplink grant, or transmission using an uplink grant.

[0077] According to an example embodiment, the timer is extended and / or adapted to support longer SDT sessions. Extending the timer may include, for example, doubling or increasing the timer duration. The timer duration may be determined based on the amount of data in the buffer of the apparatus 200 and / or the number of SDT data radio bearers (DRBs) with data. The RAN 250 may be configured to estimate the approximate duration of the timer based on the BSR report. The timer may include, for example, the T319 timer of the 3GPP specification.

[0078] Information about a restriction may be associated with information about how to apply the restriction. For example, a restriction may be associated with information defining one or more exceptions for applying the restriction.

[0079] According to an example embodiment, the information related to the restriction of performing a random access procedure includes at least one criterion for applying the restriction. The at least one criterion may include, for example, an exception related to applying the restriction. For example, the at least one criterion may define that the restriction does not apply to transmissions other than the SDT procedure and / or data including a predetermined priority.

[0080] The apparatus 200 may be configured to receive information related to restrictions on performing a random access procedure from a radio access network, such as the RAN 250 .

[0081] According to an example embodiment, the apparatus 200 is configured to receive information related to restriction of performing a random access procedure via a contention resolution message of a random access procedure associated with a small data transmission procedure.

[0082] The contention resolution message indicates to the apparatus 200 that the RAN 250 has successfully decoded the SDT data received from the apparatus 200. The contention resolution message may include, for example, MsgB or Msg4 for the random access procedures of 2-step RA or 4-step RA, respectively, of the 3GPP specification.

[0083] The contention resolution message may include, for example, a dedicated physical random access channel (PRACH) preamble allocation to be used for contention-free random access (CFRA), or may also include a dedicated scheduling request (SR) resource for requesting an uplink grant when a BSR is triggered.

[0084] According to an example embodiment, the contention resolution message includes an indication of a dedicated physical random access channel preamble to be used for contention-free random access, and the restricted random access procedure includes a contention-based random access procedure. The apparatus 200 may be configured to release the dedicated physical random access channel preamble after expiration of a timer.

[0085] According to an example embodiment, the dedicated physical random access channel preamble is valid in a synchronization signal block (SSB) where small data transmission is performed. The SSB may sometimes be referred to as a synchronization signal and physical broadcast channel (PBCH) block.

[0086] According to another example embodiment, the dedicated physical random access channel preamble is valid in at least one synchronization signal block indicated by the RAN 250 .

[0087] According to an example embodiment, the contention resolution message includes an indication of a dedicated scheduling request resource requesting an uplink grant when a buffer status report is triggered.

[0088] According to an example embodiment, the dedicated scheduling request resource is valid in a synchronization signal block in which small data transmission is performed.

[0089] According to another example embodiment, the dedicated scheduling request resource is valid in at least one synchronization signal block indicated by the RAN 250 .

[0090] According to another example embodiment, the apparatus 200 is configured to receive information related to restrictions on performing a random access procedure via system information of a radio access network such as the RAN 250 .

[0091] According to an example embodiment, the contention resolution message comprises an indication of a dedicated scheduling request resource to be used.The apparatus 200 may be configured to release the dedicated scheduling request resource after expiration of the timer.

[0092] According to an example embodiment, the apparatus 200 is configured to restrict the random access procedure based on the information related to the restriction. Restricting the RA procedure based on the information related to the restriction may include, for example, predicting the RA procedure during the SDT procedure.

[0093] As above, information about a restriction may be associated with information about how to apply the restriction. For example, a restriction may be associated with information defining one or more exceptions for applying the restriction.

[0094] According to an example embodiment, the restriction may be applied to a specific synchronization signal block (SSB) in which small data transmission is performed. According to an example embodiment, the restriction is invalid in one or more SSBs other than the SSB in which small data transmission is performed. In some examples, the apparatus 200 may apply an availability condition for the SSB. In some examples, the availability condition may include a signal level and / or quality threshold, such as a reference signal received power (RSRP), a reference signal received quality (RSRQ), or a signal to interference and noise ratio (SINR) threshold.

[0095] According to an example embodiment, in response to the apparatus 200 determining that the SSB for performing the small data transmission is unavailable, the apparatus 200 may perform a second RA procedure. In some examples, the apparatus 200 may be configured to determine that the SSB is unavailable when the RSRP, RSRQ, or SINR measured on the SSB is lower than an RSRP, RSRQ, or SINR threshold, respectively. According to an example embodiment, the apparatus 200 is configured to perform the small data transmission procedure using configured grant (CG) resources. In some examples, the CG resources include pre-configured physical uplink shared channel (PUSCH) resources that the apparatus 200 can use for the SDT procedure. In some examples, the CG resources used for the SDT procedure may be valid on at least one SSB indicated by the RAN 250. In some examples, the CG resources used for the SDT procedure may be valid if the apparatus 200 has valid uplink synchronization to the RAN 250. In some examples, the uplink synchronization may be valid on at least one SSB indicated by the RAN 250. In some examples, uplink synchronization may be effective on the SSB used when apparatus 200 is placed in an inactive mode by RAN 250 .

[0096] Without limiting the scope of the claims, an advantage of limiting the random access procedure is that uplink resources for a subsequent small data transmission procedure may be provided to the terminal device before the terminal device initiates the random access procedure.

[0097] According to an example embodiment, the apparatus 200 is configured to enable initiation of a random access procedure after restriction on performing the random access procedure is terminated.

[0098] Without limiting the scope of the claims, an advantage of enabling initiation of a random access procedure when restrictions are terminated is that when the terminal device initiates the random access procedure, uplink resources may be used for a subsequent small data transmission procedure.

[0099] Similar to the apparatus 200, the RAN 250 includes an operatively connected processor that reads from and writes to a memory. The processor may also be configured to receive control signals received via an input interface and / or the processor may be configured to output control signals via an output interface. In an example embodiment, the processor may be configured to convert received control signals into appropriate commands for controlling the functionality of the apparatus.

[0100] The memory stores computer program instructions that, when loaded into the processor, control the operation of the RAN 250, as described below. In other examples, the RAN 250 may include more than one memory or different types of storage devices.

[0101] According to an example embodiment, the RAN 250 is configured to receive an indication of a small data transfer procedure.

[0102] The indication of the small data transmission procedure may include, for example, a message for initiating the first random access procedure. For example, the indication of the first random access procedure may include a random access request (such as Msg1 or MsgA of the 3GPP specification).

[0103] According to an example embodiment, RAN 250 is configured to transmit information related to restrictions on performing a random access procedure during a small data transmission procedure based on the indication.According to an example embodiment, RAN 250 is configured to transmit information related to restrictions on performing a random access procedure to apparatus 200.

[0104] According to an example embodiment, the RAN 250 is configured to transmit information related to restrictions on performing the random access procedure via a contention resolution message of a random access procedure associated with a small data transmission procedure.

[0105] According to an example embodiment, the RAN 250 is configured to transmit information related to restrictions on performing a random access procedure via system information of the RAN 250 .

[0106] According to an example embodiment, the information related to the restriction of performing the random access procedure includes an instruction for restricting the initiation of the random access procedure. For example, the information related to performing the RA procedure may include an instruction for restricting or preventing the initiation of the second RA procedure.

[0107] According to an example embodiment, the information related to the restriction includes at least one criterion for applying the restriction. The at least one criterion may include, for example, an exception related to applying the restriction. For example, the at least one criterion may define that the restriction does not apply to transmissions other than SDT processes and / or data including a predetermined priority.

[0108] According to an example embodiment, the RAN 250 is configured to configure an uplink grant for a random access procedure concurrently with the small data transmission procedure.

[0109] According to an example embodiment, the apparatus 200 comprises means for performing the features of the apparatus 200, wherein the means for performing comprises at least one processor 210, at least one memory 260 comprising computer program code 220, the at least one memory 260 and the computer program code 220 being configured to, together with the at least one processor 210, cause execution of the apparatus 200.

[0110] According to an example embodiment, apparatus 200 includes: means for initiating a small data transmission procedure; means for receiving information related to restrictions on performing a random access procedure during the small data transmission procedure; and means for restricting the random access procedure based on the information related to the restrictions.

[0111] According to an example embodiment, the apparatus 200 may further include: a component for receiving information related to restriction of performing a random access procedure via a contention resolution message of a random access procedure associated with a small data transmission procedure or via system information of the RAN 250, and / or a component for enabling initiation of a random access procedure when the restriction of performing a random access procedure is terminated.

[0112] According to an example embodiment, the RAN 250 includes means for performing the features of the RAN 250, wherein the means for performing includes at least one processor, at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause execution of the RAN 250.

[0113] According to an example embodiment, the RAN 250 includes means for receiving an indication of a small data transfer procedure and means for transmitting information related to restrictions on performing a random access procedure during the small data transfer procedure based on the indication. The RAN may also include means for configuring an uplink grant for the random access procedure concurrently with the small data transfer procedure.

[0114] Figure 3 The example method 300 is illustrated incorporating aspects of previously disclosed elements. More specifically, the example method 300 illustrates limiting a random access procedure during a small data transmission procedure. The method 300 may be performed by the apparatus 200.

[0115] The method begins by initiating 305 a small data transfer process. The small data transfer process involves transmitting data while the device 200 is in an inactive state.

[0116] The method continues with receiving 310 information related to restrictions on performing a random access procedure during the small data transmission procedure.The information related to restrictions on performing a random access procedure may include instructions, parameter values ​​and / or one or more criteria for applying the restrictions.

[0117] The method further continues by restricting 315 the random access procedure based on the restriction-related information. Restricting the random access procedure based on the restriction-related information may include, for example, predicting the random access procedure during the small data transmission procedure.

[0118] Figure 4 Another example method 400 is illustrated that combines aspects of previously disclosed elements. More specifically, the example method 400 illustrates limiting a random access procedure during a small data transmission procedure. The method 400 may be performed by the RAN 250.

[0119] The method begins by receiving 405 an indication of a small data transmission procedure. The indication of the small data transmission procedure may include, for example, a message for initiating a first random access procedure. For example, the indication of the first random access procedure may include a random access request (such as Msg1 or MsgA of the 3GPP specification).

[0120] The method continues by transmitting 410 information related to restrictions on performing a random access procedure during the small data transmission procedure based on the indication. Transmitting the information related to restrictions on performing the random access procedure may include transmitting the information via a contention resolution message of a random access procedure associated with the small data transmission procedure or via system information of the RAN 250.

[0121] Figure 5 An example signaling diagram is shown in conjunction with various aspects of the previously disclosed embodiments. Figure 5 In the example of , it is assumed that the apparatus 200 includes a terminal device configured to communicate with the RAN 250.

[0122] exist Figure 5In the example of FIG5 , the terminal device sends 505 to the RAN an indication of a small data transfer procedure initiated by the terminal device. The small data transfer procedure includes transmitting data in an inactive state of the terminal device. The terminal device may be configured to initiate an SDT procedure in response to receiving one or more data packets in a data buffer of the terminal device.

[0123] Based on the indication, the RAN transmits 510 information related to the restriction of performing a random access procedure during the small data transmission procedure. The RAN may transmit the information related to the restriction of performing a random access procedure via a contention resolution message of the random access procedure associated with the small data transmission procedure or via system information of the RAN.

[0124] The terminal device restricts 515 the random access procedure based on the information on restriction of performing the random access procedure during the small data transmission procedure, and the RAN configures 520 an uplink grant for the random access procedure simultaneously with the small data transmission procedure.

[0125] The terminal device enables 530 initiation of a random access procedure after the restriction on performing the random access procedure is terminated.

[0126] Without limiting the scope of the claims, an advantage of limiting subsequent random access procedures during small data transmissions is that it prevents the terminal device from unnecessarily accessing a random access procedure to request uplink resources, for example, when the RAN already plans to provide new uplink resources to the terminal device for transmission.

[0127] Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example embodiments disclosed herein is that uplink resources may be provided to a terminal device in a resource-efficient manner for subsequent small data transmission.

[0128] As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) a purely hardware circuit implementation (such as an implementation using only analog and / or digital circuitry), and (b) a combination of hardware circuitry and software, such as (as applicable):

[0129] (i) a combination of analog and / or digital hardware circuits and software / firmware, and (ii) any portion of a hardware processor with software, including a digital signal processor, software, and memory, that work together to enable a device (such as a mobile phone or server) to perform various functions, and (c) hardware circuits and / or processors, such as a microprocessor or portion of a microprocessor, that require software (e.g., firmware) to operate, but the software may not be present when the software is not required for operation.

[0130] Embodiments of the present invention may be implemented using software, hardware, application logic, or a combination of software, hardware, and application logic. The software, application logic, and / or hardware may reside on an apparatus, a separate device, or multiple devices. If desired, part of the software, application logic, and / or hardware may reside on the apparatus, part of the software, application logic, and / or hardware may reside on a separate device, and part of the software, application logic, and / or hardware may reside on multiple devices. In example embodiments, the application logic, software, or instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a "computer-readable medium" may be any medium or component that can contain, store, communicate, propagate, or transmit instructions for use by or in connection with an instruction execution system, apparatus, or device (such as a computer), and further in Figure 2 An example of a computer is described and illustrated in . Computer-readable media may include computer-readable storage media, which may be any medium or component that can contain or store instructions for use by or in connection with an instruction execution system, apparatus, or device (e.g., a computer).

[0131] If desired, the different functions discussed herein may be performed in different orders and / or simultaneously with each other. In addition, if desired, one or more of the above functions may be optional or may be combined.

[0132] Although various aspects of the invention are set out in the independent claims, further aspects of the invention comprise other combinations of features from the described embodiments and / or dependent claims with features of the independent claims, and not just the combinations explicitly set out in the claims.

[0133] It is obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways.The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. An apparatus for communication, comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to at least: receiving information related to a restriction on performing a random access procedure during a small data transmission procedure, wherein the information related to the restriction on performing the random access procedure comprises: A timer and a trigger condition for starting the timer; as well as The random access procedure is restricted based on the information related to the restriction.

2. The apparatus according to claim 1, wherein the small data transmission process comprises: Data is transmitted during an inactive state of the device.

3. The apparatus according to claim 1 , wherein the information related to the restriction on performing the random access procedure comprises: An instruction to restrict initiation of the random access procedure.

4. The apparatus according to claim 1 , wherein the information related to the restriction on performing the random access procedure comprises: Information about the timing of the restriction.

5. The apparatus according to claim 1 , wherein the information related to the restriction on performing the random access procedure comprises: A time period for limiting the initiation of the random access procedure.

6. The apparatus according to claim 1, wherein the information related to the restriction on performing the random access procedure comprises: The moment when the device is allowed to initiate the random access procedure.

7. The apparatus of claim 1 , wherein the triggering condition for starting the timer comprises at least one of: completion of contention resolution of a random access procedure associated with the small data transmission procedure; completion of the random access procedure associated with the small data transmission procedure; reception of an uplink grant; or transmission using an uplink grant.

8. The apparatus according to claim 1, wherein the information related to the restriction on performing a random access procedure comprises: At least one criterion for applying the restriction.

9. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: receive information related to the restriction on performing a random access procedure via system information of a wireless access network.

10. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to: enable initiation of the random access procedure after the restriction on performing the random access procedure is terminated. The apparatus according to claim 1 , wherein the apparatus comprises a terminal device.

12. A method for communication, comprising: receiving information related to restriction of performing a random access procedure during a small data transmission procedure, wherein the information related to the restriction of performing the random access procedure comprises: a timer and a trigger condition for starting the timer; and The random access procedure is restricted based on the information related to the restriction.

13. An apparatus for communication, comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to at least: receiving an indication of a small data transfer in progress; and transmitting, based on the indication, information related to a restriction on performing a random access procedure during the small data transmission procedure, wherein the information related to the restriction on performing the random access procedure comprises: A timer and a trigger condition for starting the timer.

14. The apparatus of claim 13 , wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: transmit the information related to the restriction on performing the random access procedure via a contention resolution message of a random access procedure associated with the small data transmission procedure.

15. The apparatus of claim 13, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to: transmit the information related to the restriction on performing a random access procedure via system information of the apparatus.

16. The apparatus according to claim 13, wherein the information related to the restriction on performing a random access procedure comprises: An instruction for restricting the initiation of the random access procedure.

17. The apparatus of claim 13, wherein the information related to the restriction comprises: At least one criterion for applying the restriction.

18. The apparatus of claim 13, wherein the apparatus comprises a wireless access network.

Images