Random access with support of custom constellations

Abstract

Example embodiments of the present disclosure relate to support of random access to a custom constellation. A method includes selecting a first preamble, the first preamble indicating support of a custom constellation by a first apparatus; transmitting the first preamble to a network device for initiating a random access procedure with the network device; receiving, from the network device, an indication indicating a selection of a modulation and coding scheme (MCS); and transmitting, to the network device, uplink data based on the MCS.

Description

Technical Field

[0001] Various exemplary embodiments of this disclosure generally relate to the telecommunications field, and more particularly to methods, apparatuses, devices, and computer-readable storage media for random access to support customized constellations. Background Technology

[0002] A communication network can be used as a facility to enable communication between two or more communication devices or to provide communication devices with access to a data network. A mobile or wireless communication network is an example of a communication network. Communication networks can operate according to standards provided by organizations such as the 3rd Generation Partnership Project (3GPP) or the European Telecommunications Standards Institute (ETSI). Examples of standards provided by 3GPP are the so-called 3GPP standards for cellular technologies, such as those for 4G, 5G, and 6G technologies. Summary of the Invention

[0003] In a first aspect of this disclosure, a first apparatus is provided. The first apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to at least: select a first preamble indicating support for a custom constellation; send the first preamble to a network device for initiating a random access procedure with the network device; receive from the network device an instruction indicating the selection of a modulation and coding scheme (MCS); and, based on the MCS, send uplink data to the network device.

[0004] In a second aspect of this disclosure, a second apparatus is provided. The second apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to at least: receive from a terminal device a first preamble for initiating a random access procedure with the second apparatus, the first preamble indicating support for a custom constellation by the terminal device; send to the terminal device an instruction indicating the selection of a modulation and coding scheme (MCS); and receive uplink data transmitted based on the MCS from the terminal device.

[0005] In a third aspect of this disclosure, a method is provided. The method includes: selecting a first preamble indicating support for a custom constellation by a first device; sending the first preamble to a network device for initiating a random access procedure with the network device; receiving from the network device an indication of selection of a modulation and coding scheme (MCS); and sending uplink data to the network device based on the MCS.

[0006] In a fourth aspect of this disclosure, a method is provided. The method includes: receiving from a terminal device a first preamble for initiating a random access procedure with a second device, the first preamble indicating support for a custom constellation by the terminal device; sending to the terminal device an indication for selecting a modulation and coding scheme (MCS); and receiving uplink data transmitted based on the MCS from the terminal device.

[0007] In a fifth aspect of this disclosure, a first apparatus is provided. The first apparatus includes: components for selecting a first preamble, the first preamble indicating support for a custom constellation by the first apparatus; components for sending the first preamble to a network device for initiating a random access procedure with the network device; components for receiving from the network device an indication of selection of a modulation and coding scheme (MCS); and components for sending uplink data to the network device based on the MCS.

[0008] In a sixth aspect of this disclosure, a second apparatus is provided. The second apparatus includes: components for receiving from a terminal device a first preamble for initiating a random access procedure with the second apparatus, the first preamble indicating support for a custom constellation by the terminal device; components for sending to the terminal device an indication of selection of a modulation and coding scheme (MCS); and components for receiving uplink data transmitted from the terminal device based on the MCS.

[0009] In a seventh aspect of this disclosure, a computer-readable medium is provided. The computer-readable medium includes instructions stored thereon for causing a device to at least execute the method according to a third aspect.

[0010] In an eighth aspect of this disclosure, a computer-readable medium is provided. The computer-readable medium includes instructions stored thereon for causing a device to at least execute the method according to the fourth aspect.

[0011] It should be understood that the summary portion is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0012] Some exemplary embodiments will now be described with reference to the accompanying drawings, in which: Figure 1 An example communication environment in which example embodiments of this disclosure may be implemented is shown; Figure 2 A schematic diagram of an example four-step RACH process is shown; Figure 3 A schematic diagram of an example two-step RACH process is shown; Figure 4AA schematic diagram of an example contention-based random access (CBRA) with a four-step RA type is shown; Figure 4B A schematic diagram of an example CBRA with a two-step RA type is shown; Figure 4C A schematic diagram of an example contention-free random access (CFRA) with a four-step RA type is shown; Figure 4D A schematic diagram of an example CFRA with a two-step RA type is shown; Figure 5 A schematic diagram of an example rollback procedure for a CBRA with a two-step RA type is shown; Figure 6 An example signaling flow for a four-step random access procedure supporting a custom constellation, according to some example embodiments of this disclosure, is shown; Figure 7A The signaling flow of an example CBRA procedure for supporting custom constellations according to some example embodiments of this disclosure is shown; Figure 7B The signaling flow of an example CFRA procedure for supporting custom constellations according to some example embodiments of this disclosure is shown; Figure 8 An example signaling flow for a two-step random access procedure supporting a custom constellation according to some example embodiments of this disclosure is shown; Figure 9A The signaling flow of another example CBRA procedure for supporting custom constellations according to some example embodiments of this disclosure is shown; Figure 9B The signaling flow of another example CFRA procedure for supporting custom constellations according to some example embodiments of this disclosure is shown; Figure 10A A flowchart is shown illustrating a method implemented at a first device according to some exemplary embodiments of the present disclosure; Figure 10B A flowchart is shown illustrating a method implemented at a second device according to some example embodiments of the present disclosure; Figure 11A A flowchart is shown illustrating a method implemented at a first device according to some exemplary embodiments of the present disclosure; Figure 11B A flowchart is shown illustrating a method implemented at a second device according to some example embodiments of the present disclosure; Figure 12 A simplified block diagram of a device suitable for implementing example embodiments of the present disclosure is shown; and Figure 13 A block diagram of an example computer-readable medium according to some example embodiments of the present disclosure is shown.

[0013] In all the accompanying drawings, the same or similar reference numerals denote the same or similar elements. Detailed Implementation

[0014] The principles of this disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described for illustrative purposes only and to assist those skilled in the art in understanding and implementing this disclosure, and do not imply any limitation on the scope of this disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0015] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0016] References to "an embodiment," "embodiment," "example embodiment," etc., in this disclosure indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Additionally, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is believed that incorporating other embodiments, whether explicitly described or not, to affect such a feature, structure, or characteristic is within the knowledge of those skilled in the art.

[0017] It should be understood that although terms such as "first," "second," etc., preceding nouns may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another, and they do not restrict the order of the nouns. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0018] As used herein, “at least one of the following: ” and “at least one element in ” and similar wording (where the list of two or more elements is connected by “and” or “or”) means at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0019] As used herein, unless explicitly stated otherwise, “responding to A” does not indicate that the step is performed immediately after “A” occurs, and one or more intermediate steps may be included.

[0020] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that, when used herein, the terms “comprising,” “including,” “having,” “having,” “containing,” and / or “comprising” specify the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0021] As used in this application, the term "circuit system" may refer to one or more of the following: (a) Hardware circuit implementation only (such as implementation in analog and / or digital circuit systems only) and (b) A combination of hardware circuitry and software, such as (if applicable): (i) The combination of analog and / or digital hardware circuitry with software / firmware and (ii) Any part of a hardware processor (including a digital signal processor), software, and memory that works together to enable a device such as a mobile phone or server to perform various functions. (c) Hardware circuitry and / or processors, such as microprocessors or parts thereof, that require software (e.g., firmware) to operate, but which may not exist when no software is required to operate.

[0022] This definition of circuit system applies to all uses of the term in this application (including in any claim). As another example, as used in this application, the term circuit system also covers implementations of hardware circuitry or processors (or processors) or portions thereof and their accompanying software and / or firmware. The term circuit system also covers, for example and if applicable to a particular claim element, baseband integrated circuits or processor integrated circuits for mobile devices or similar integrated circuits in servers, cellular network devices or other computing or network devices.

[0023] As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-A Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. Furthermore, communication between terminal devices and network devices in a communication network can be performed according to any suitable generation of communication protocol, including but not limited to first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G), 5.5G, sixth-generation (6G) communication protocols and / or any other currently known or future-developed protocols. Embodiments of this disclosure can be applied to a variety of communication systems. Given the rapid development of communications, there will certainly be future types of communication technologies and systems that embody the future types of this disclosure. The scope of this disclosure should not be construed as limited to the aforementioned systems.

[0024] As used herein, the term "network device" refers to a node in a communications network through which terminal devices access the network and receive services. Depending on the terminology and technology applied, a network device can refer to a base station (BS) or access point (AP), such as a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a next-generation Node B (also known as a gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a repeater, an integrated access and backhaul (IAB) node, a low-power node (such as a femtosecond or picosecond), a non-terrestrial network (NTN) or non-terrestrial network equipment (such as satellite network equipment), low Earth orbit (LEO) satellites and geostationary Earth orbit (GEO) satellites, spacecraft network equipment, etc. In some example embodiments, the radio access network (RAN) split architecture includes a centralized unit (CU) and a distributed unit (DU) at the IAB donor node. The IAB node includes a mobile terminal (IAB-MT) portion that behaves as a UE toward the parent node, and the DU portion of the IAB node behaves as a base station toward the next-hop IAB node.

[0025] The term "terminal device" refers to any terminal device capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and recycle bins, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop mounted devices (LMEs), USB dongles, smart devices, wireless customer premises equipment (CPEs), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. The terminal equipment may also correspond to the mobile termination (MT) portion of an IAB node (e.g., a relay node). In the following description, the terms "terminal equipment," "communication equipment," "terminal," "user equipment," and "UE" are used interchangeably.

[0026] As used herein, the terms “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” can refer to any resource used to perform communication, such as communication between a terminal device and a network device, including resources in the time domain, frequency domain, spatial domain, code domain, or any other combination of time-domain, frequency-domain, spatial-domain, and / or code-domain resources used to implement communication. In the following, unless explicitly stated otherwise, resources in the frequency and time domains will be used as examples of transmission resources used to describe some exemplary embodiments of this disclosure. Note that the exemplary embodiments of this disclosure are equally applicable to other resources in other domains.

[0027] Figure 1 A schematic diagram of an example communication environment 100 in which exemplary embodiments of the present disclosure may be implemented is shown. In the communication environment 100, multiple communication devices, including terminal device 110 and network device 120, can communicate with each other.

[0028] exist Figure 1 In the example, terminal device 110 may be a UE, and network device 120 may be a base station serving the UE. Network device 120 operates in a radio access network (RAN) and is therefore also referred to as a RAN network device.

[0029] It should be understood that, Figure 1 The number of devices and their connections shown are for illustrative purposes only and do not imply any limitation. Communication environment 100 may include any suitable number of devices configured to implement the exemplary embodiments of this disclosure. It should be noted that although shown as a network device, network device 120 may be another device besides a network device. Although shown as a terminal device, terminal device 110 may be another device besides a terminal device.

[0030] In the following description, for illustrative purposes, some example embodiments are described in which terminal device 110 operates as a UE and network device 120 operates as a base station (e.g., gNB). However, in some example embodiments, the operations described in connection with the terminal device can be implemented at the network device or other devices, and the operations described in connection with the network device can be implemented at the terminal device or other devices.

[0031] In some example embodiments, the communication direction from network device 120 to terminal device 110 is referred to as the downlink (DL), and the communication direction from terminal device 110 to network device 120 is referred to as the uplink (UL). In the DL, network device 120 is a transmitting (TX) device (or transmitter), and terminal device 110 is a receiving (RX) device (or receiver). In the UL, terminal device 110 is a TX device (or transmitter), and network device 120 is an RX device (or receiver).

[0032] Communication in communication environment 100 may be implemented according to any suitable communication protocol, including but not limited to cellular communication protocols, wireless local network communication protocols such as IEEE 802.11, and / or any other currently known or future-developed protocols. Furthermore, communication may utilize any suitable wireless communication technology, including but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple Input Multiple Output (MIMO), Orthogonal Frequency Division Multiple Access (OFDM), Discrete Fourier Transform Extended OFDM (DFT-s-OFDM), and / or any other currently known or future-developed technologies.

[0033] A terminal device (e.g., a UE) can initiate communication with a network device (e.g., a gNB) through a random access channel (RACH) procedure or a random access procedure, which is the initial step in establishing a connection with the network. The RACH procedure may include a four-step RACH procedure (also known as the default RACH procedure) or a two-step RACH procedure (also known as the enhanced RACH procedure).

[0034] Figure 2A schematic diagram of an example four-step RACH process 200 is shown. (As follows) Figure 2 As shown, for a four-step RACH procedure, the UE and gNB may exchange messages 1 (Msg1), 2 (Msg2), 3 (Msg3), and 4 (Msg4). In the first step (Msg1), the UE sends a predefined preamble sequence on the Physical Random Access Channel (PRACH) to initiate the random access (RA) procedure. The gNB monitors the PRACH, detects the preamble, and responds with Msg2. Msg2 may include initial link configuration, such as a time advance command, initial uplink grant, random access radio network temporary identifier (RA-RNTI), etc. In the uplink grant, the gNB configures some transmission parameters, such as frequency and time resources, as well as modulation and coding schemes for subsequent uplink transmissions. Table 1 shows an example of uplink grant in Msg2.

[0035] Table 1: Uplink Grant in Msg2

[0036] Upon receiving Msg2, the UE transmits Msg3 on the Physical Uplink Shared Channel (PUSCH), which may carry user data or RRC messages, such as Radio Resource Control (RRC) connection requests, RRC connection restoration requests, etc. After receiving and decoding Msg3, the gNB sends Msg4 to the UE for contention resolution purposes. Msg4 may contain the UE identifier (ID), confirmation that the gNB has identified the UE, etc.

[0037] Figure 3 A schematic diagram of an example two-step RACH process 300 is shown. (As follows) Figure 3 As shown, for a two-step RACH procedure, the UE and gNB can involve message A (MsgA) and message B. For latency-sensitive applications, the two-step RACH procedure can be defined by combining Msg1+Msg3 into MsgA and combining Msg2+Msg4 into MsgB.

[0038] The random access procedure can be triggered by multiple events, including but not limited to: initial access from RRC_IDLE, RRC connection reconstruction procedure, arrival of DL or UL data during RRC_CONNECTED when the UL synchronization state is "asynchronous", arrival of UL data during RRC_CONNECTED when no PUCCH resources for SR are available, handover, ER failure, explicit request by RRC during synchronization reconfiguration, RRC connection recovery procedure from RRC_INACTIVE to establish time alignment for the secondary timing advance group (TAG), request for other system information (SI), beam failure recovery, and consistent UL listen-before-transmit (LBT) failure on a special cell (SpCell).

[0039] Both types of random access procedures (i.e., four-step RA and two-step RA) support CBRA and CFRA. The UE selects the type of random access based on network configuration when initiating a random access procedure. For example, when CFRA resources are not configured, the UE can use an RSRP threshold to select between two-step and four-step RA types. When CFRA resources are configured for the four-step RA type, the UE can perform random access using the four-step RA type. When CFRA resources are configured for the two-step RA type, the UE can perform random access using the two-step RA type.

[0040] The network can not simultaneously configure CFRA resources for both four-step RA type and two-step RA type for the Bandwidth Part (BWP). CFRA with two-step RA type can be supported only for handover.

[0041] The Msg1 for a four-step RA type can consist of a preamble on the PRACH. After the Msg1 transmission, the UE can monitor for responses from the network within a configured window. For CFRA, a dedicated preamble for the Msg1 transmission can be assigned by the network, and the UE can terminate the random access procedure upon receiving a random access response from the network, such as... Figure 4C As shown, Figure 4C A schematic diagram of an example CFRA procedure 400C with a four-step RA type is shown. For CBRA, upon receiving a random access response, the UE sends Msg3 using the UL grant scheduled in the response and monitors contention resolution, such as... Figure 4A As shown, it illustrates a schematic diagram of an example CBRA procedure 400A with a four-step RA type. If contention resolution is unsuccessful after Msg3 (re)transmission, the UE can return to Msg1 transmission.

[0042] A two-step RA type MsgA can include a preamble on the PRACH and a payload on the PUSCH. After the MsgA transmission, the UE can monitor for a response from the network within a configured window. For CFRA, dedicated preamble and PUSCH resources can be configured for MsgA transmission, and the UE can terminate the random access procedure upon receiving a network response, such as... Figure 4D As shown, the Figure 4D A schematic diagram of an example CFRA procedure 400D with a two-step RA type is shown. For CBRA, if contention resolution is successful upon receiving a network response, the UE can terminate the random access procedure, such as... Figure 4B As shown, the Figure 4B A schematic diagram of an example CBRA process 400B with a two-step RA type is shown.

[0043] If a fallback indication is received in MsgB, the UE can use the UL grant scheduled in the fallback indication to perform Msg3 transmission and monitor contention resolution, such as Figure 5 As shown, the Figure 5 A schematic diagram of an example fallback procedure 500 for a CBRA with a two-step RA type is shown. If contention resolution is unsuccessful after a Msg3 (re)transmission, the UE can return to a MsgA transmission. If a random access procedure with a two-step RA type is not completed after multiple MsgA transmissions, the UE can be configured to switch to a CBRA with a four-step RA type.

[0044] Deep MIMO transceivers are promising candidates for 6G physical layer designs, expected to exhibit superior performance compared to their traditional counterparts. Constellation learning at the transmitter (TX) is likely one of the key components that makes deep transceivers more interesting compared to conventional transceivers with regular quadrature amplitude modulation (QAM) constellations. For example, a solution has been proposed where the constellation points of the modulation mapper in an orthogonal frequency division multiplexing (OFDM) modulator are treated as part of the training parameters to achieve pilot-free communication. However, this could lead to higher spectral efficiency because resources may not need to be allocated for pilot transmissions.

[0045] Quadrature Phase Shift Keying (QPSK) constellations and QAM constellations have been introduced into communication systems. Table 2 shows examples of standardized 16-QAM constellation points and the bits assigned to each constellation point.

[0046] Table 2 16-QAM Modulation Mapping

[0047] During the RACH process, the UE establishes its first connection to the gNB. This process can begin with the UE sending a randomly generated preamble via Msg1. After the gNB successfully detects the preamble, it can respond by configuring UL authorization for the UE via Msg2. In the UL authorization, the gNB can specify which resources, TX power, MCS, etc., the UE is allowed to use for its subsequent UL transmissions in Msg3. For example, the MCS index signaled in Msg2 can be selected from values ​​of a predefined group in a specific MCS table. When a custom constellation is introduced as an alternative to or in combination with a QAM constellation, the UE and gNB may need to agree on the use of the custom constellation during the RACH process. For example, the UE should indicate to the gNB whether it has the capability to support a custom constellation (e.g., potentially via Msg1). The gNB can then configure UL authorization with or without supporting the custom constellation (in Msg2). However, supporting custom constellations for the RACH process remains an open problem that needs to be addressed.

[0048] According to some example embodiments of this disclosure, a random access solution supporting a custom constellation is provided. A terminal device selects a first preamble indicating its support for a custom constellation and sends the first preamble to a network device to initiate a random access procedure with the network device. The terminal device receives an indication from the network device indicating the selection of a modulation and coding scheme (MCS), and then sends uplink data to the network device based on the MCS. In this way, by allowing the terminal device to indicate its support for a custom constellation and dynamically select the MCS based on this information, communication efficiency can be improved and resource allocation can be optimized.

[0049] The exemplary embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0050] Figure 6 An example signaling flow 600 of a four-step random access procedure supporting a custom constellation according to some example embodiments of this disclosure is shown. Reference will be made to this document for discussion purposes. Figure 1 Discuss signaling flow 600. For example... Figure 6 As shown, signaling flow 600 involves terminal device 110 and network device 120. In some example embodiments, terminal device 110 may be a UE or may be included in a UE. Network device 120 may include a gNB or may be included in a gNB.

[0051] If terminal device 110 supports a custom constellation, then in order to initiate a random access procedure with network device 120, terminal device 110 selects (601) a first preamble indicating that terminal device 110 supports a custom constellation.

[0052] As used herein, the term "constellation" can refer to the arrangement of modulation symbols in the complex plane (I / Q plane), representing the mapping of digital bits to analog signal waveforms. Constellations can include regular constellations, such as QAM constellations (e.g., 16-QAM constellations, 64-QAM constellations, 256-QAM constellations, etc.), where constellation points are uniformly spaced in a square grid. In exemplary embodiments of this disclosure, a "custom constellation" can refer to a constellation that can be customized, designed, or optimized for specific channel conditions, system requirements, security purposes, energy-efficient transmission, or performance goals. Custom constellations can also be referred to as irregular constellations, asymmetric constellations, non-uniform constellations, artificial intelligence (AI) based constellations, machine learning (ML) based constellations, hybrid constellations, etc.

[0053] In some cases, terminal device 110 may select a first preamble from a first preamble group (also called a first preamble pool or first preamble set) indicating support for a custom constellation. The first preamble group indicating support for a custom constellation may implicitly indicate that terminal device 110 supports an MCS table with a custom constellation (and possibly a traditional QAM constellation). For example, terminal device 110 may know its capabilities, and if terminal device 110 knows it supports a custom constellation, it may select a first preamble from the first preamble group. Terminal device 110 sends (603) the first preamble to network device 120 to initiate a random access procedure with network device 120.

[0054] In some other cases, if terminal device 110 knows that it does not support (i.e., fails to support) a custom constellation, terminal device 110 can select a second preamble from a second preamble group (also called a second preamble pool or second preamble set) indicating lack of support for the custom constellation. The second preamble group indicating lack of support for the custom constellation may implicitly indicate that terminal device 110 only supports MCS tables with traditional QAM constellations. If terminal device 110 wants to communicate with network device 120 that only supports traditional constellations and does not support custom constellations, terminal device 110 can then send the second preamble to network device 120 to initiate a random access procedure with network device 120. The first preamble may include a RACH preamble, and the second preamble may also include a RACH preamble. The first preamble group may include multiple RACH preambles, and the second preamble group may include multiple RACH preambles.

[0055] In this disclosure, it is worth noting that if the terminal device 110 does not support a custom constellation, then the terminal device 110 may only support a traditional constellation (e.g., a QAM constellation). If the terminal device 110 supports a custom constellation, then the terminal device 110 may support both custom constellations and traditional constellations.

[0056] In some example embodiments, network device 120 may send the corresponding configurations of a first preamble (or a first preamble group) and / or a second preamble (or a second preamble group) to terminal device 110. For example, in some cases, network device 120 may send the configuration of the first preamble group to terminal device 110. As an example, if network device 120 knows in advance that terminal device 110 supports a custom constellation, network device 120 may send the corresponding configuration of the first preamble to terminal device 110. Terminal device 110 may generate and select a first preamble based on the received configuration, and then send the first preamble to network device 120 for initiating a random access procedure with network device 120.

[0057] In some example embodiments, network device 120 may not know in advance whether terminal device 110 supports a custom constellation. Network device 120 can assign corresponding configurations for the first preamble and the second preamble to terminal device 110. Terminal device 110 can select the corresponding preamble based on whether it supports a custom constellation. For example, if terminal device 110 supports a custom constellation, it can select the first preamble based on that configuration. Otherwise, terminal device 110 can select the second preamble based on that configuration.

[0058] In some example embodiments, the random access procedure may include a CBRA procedure or a CFRA procedure. Depending on the random access procedure, the configuration of the first preamble and the second preamble may be received in different ways. This configuration may be received by the terminal device 110 via system information or dedicated signaling. For example, for a CBRA procedure, the terminal device 110 may receive the configuration via system information. For a CFRA procedure, the terminal device 110 may receive the configuration via dedicated signaling.

[0059] For the CBRA process, if terminal device 110 supports both custom constellations and traditional constellations, terminal device 110 can generate and select a first preamble; or if terminal device 110 only supports traditional constellations, terminal device 110 can generate and select a second preamble, and then send the selected preamble (first preamble or second preamble) to network device 120. For example, terminal device 110 can receive a corresponding configuration from network device 120 and therefore be able to generate a first preamble group and a second preamble group based on that configuration. Then, if terminal device 110 determines that it supports custom constellations, it can select or randomly select a first preamble from the first preamble group. If terminal device 110 determines that it does not support custom constellations, it can select or randomly select a second preamble from the second preamble group.

[0060] For the CFRA procedure, terminal device 110 may receive, for example, two preambles from network device 120: one preamble indicating support for a custom constellation (e.g., preamble A), and another preamble indicating non-support for the custom constellation (e.g., preamble B). If terminal device 110 supports both custom constellations and legacy constellations, terminal device 110 may choose preamble A; or, if terminal device 110 only supports legacy constellations, terminal device 110 may choose preamble B, and then send the selected preamble (preamble A or preamble B) to network device 120.

[0061] In some example embodiments, the preamble in the first preamble group can be generated based on the length of the first root sequence used to generate the first preamble group. The preamble in the second preamble group can be generated based on the length of the second root sequence used to generate the second preamble group. The first root sequence may be different from the second root sequence. In some cases, the preamble group... (That is, a set of preambles) can be generated according to the following formula:

[0062] Therefore, the frequency domain representation can be generated according to the following formula:

[0063] in L RA It is the root sequence x u （i） The length of the first preamble group. In some cases, as an example, the first preamble group indicating support for custom constellations (and implicit support for QAM constellations) can be based on the length. L RA =829 , L RA =137 , L RA =1147 or L RA =569 This is used to generate the code. In this way, short and long preambles for frequency ranges 1 (FR1) and FR2 can be adapted. A second preamble group used to indicate lack of support for a custom constellation can be based on length. L RA =839 , L RA =139 , L RA =1151 or L RA=571 To generate. Length L RA The value can be determined based on the format of the preamble, which is not restricted in this disclosure.

[0064] It should be understood that, in the embodiments of this disclosure, the first preamble group can be generated based on any other length or other method, which is not limited in this disclosure. The first preamble group can be generated in any other way, as long as the first preamble group and the second preamble group do not intersect with each other.

[0065] In some example embodiments, the first preamble may be included in the first message of the random access procedure sent to network device 120. For example, in the case that the random access procedure is a four-step RACH procedure, the first message may be Msg1 from terminal device 110 to network device 120. The first preamble may be included in Msg1.

[0066] If terminal device 110 supports a custom constellation, network device 120 receives (605) a first preamble from terminal device 110. If terminal device 110 does not support a custom constellation, network device 120 may receive a second preamble from terminal device 110. Based on the received preamble, network device 120 determines whether terminal device 110 supports a custom constellation and then selects an MCS for uplink transmissions from terminal device 110.

[0067] Network device 120 sends (607) an instruction indicating the selection of an MCS. Terminal device 110 receives (609) an instruction from network device 120 indicating the selection of an MCS. For example, network device 120 may send an instruction to terminal device 110 indicating whether to select an MCS from a first MCS table (also called an enhanced MCS table) that includes at least one MCS corresponding to a custom constellation, or from a second MCS table (also called a traditional MCS table) that does not include MCS corresponding to a custom constellation. In some examples, the first MCS table may also include at least one MCS corresponding to a traditional QAM constellation in addition to the custom constellation. In some other examples, the MCS corresponding to the custom constellation and the MCS corresponding to the traditional QAM constellation may be defined in separate MCS tables.

[0068] For example, if network device 120 determines that terminal device 110 supports a custom constellation, network device 120 may instruct terminal device 110 to select an MCS from a first MCS table. If network device 120 determines that terminal device 110 does not support a custom constellation, network device 120 may instruct terminal device 110 to select an MCS from a second MCS table. Even though network device 120 determines that terminal device 110 supports a custom constellation, there may still be situations where network device 120 instructs terminal device 110 to select an MCS from a second MCS table, which is not limited in this disclosure. The instruction from network device 120 may include an index of the selected MCS, which can be used to uniquely identify the MCS from the corresponding MCS table. In some cases, if more than one MCS table exists, the instruction may further include an index of the MCS tables. As an example, the instruction may include an index of the MCS and an index of the MCS table. Terminal device 110 may receive the instruction and use the index of the MCS table to find the indicated MCS table, and then use the index of the MCS to find the indicated MCS from the indicated MCS table.

[0069] In some example embodiments, this indication may be included in a second message of the random access procedure received from network device 120. As an example, if the random access procedure is a four-step RACH procedure, the second message may be Msg2. The indication may be a new field in Msg2, such as the "PUSCH-MCS table" field. The "PUSCH-MCS table" field may be set to different values ​​indicating whether an MCS is selected from a first MCS table or a second MCS table. As an example, the "PUSCH-MCS table" field may be set to 0, indicating that terminal device 110 is allowed to select an MCS from a conventional MCS table. Alternatively, the "PUSCH-MCS table" field may be set to 1, indicating that terminal device 110 is allowed to select an MCS from an enhanced MCS table.

[0070] In some example embodiments, along with an indication indicating the selection of the MCS, network device 120 can configure uplink authorization for terminal device 110 in Msg2.

[0071] Terminal device 110 sends (611) uplink data to network device 120 based on MCS. Uplink data transmission can be performed using uplink grant. Network device 120 receives (613) the uplink data sent based on MCS from terminal device 110. In some example embodiments, the uplink data may be included in a third message of the random access procedure sent to the network device. For example, in the case where the random access procedure is a four-step RACH procedure, the third message may be Msg3. The uplink data may be included in Msg3 from terminal device 110 to network device 120.

[0072] During CBRA access, network device 120 can decode Msg3. If network device 120 correctly receives the uplink data, the CBRA access process can be completed. If the transmission of uplink data conflicts with another terminal device, network device 120 can perform contention resolution, for example, by sending Msg4 to terminal device 110. During CFRA access, network device 120 can directly respond to Msg3. For example, network device 120 can allocate resources and send an RRC establishment message to establish a connection without resolving contention.

[0073] Figure 7A Signaling flow 700A for an example four-step CBRA procedure supporting custom constellations according to some example embodiments of this disclosure is shown. For example... Figure 7A As shown, signaling flow 700A involves terminal device 110 and network device 120. Signaling flow 700A can be an example of signaling flow 600.

[0074] At 701A, terminal device 110 can initiate the process by selecting which preamble pool to use. For example, terminal device 110 can select a preamble for initiating the RACH process with network device 120 from either a first preamble pool (i.e., the first preamble group as described above) or a second preamble pool (i.e., the second preamble group as described above). The first and second preamble pools can include one or more RACH preambles. For example, if terminal device 110 only supports legacy constellations (e.g., QAM constellations), it can select a preamble from the second preamble pool. If terminal device 110 supports both QAM constellations and custom constellations, it can select a preamble from the first preamble pool.

[0075] At 703A, terminal device 110 sends the selected preamble to network device 120 in Msg1. Network device 120 receives the preamble from terminal device 110. Based on the received preamble, network device 120 can configure UL authorization. In UL authorization, network device 120 can instruct terminal device 110 whether to use a traditional MCS table or a new MCS table to apply the MCS index configured by the same UL authorization. If terminal device 110 uses a second preamble pool, network device 120 can configure only the traditional MCS table. Conversely, if terminal device 110 uses a first preamble pool, network device 120 can configure either a traditional MCS table or a new MCS table. For example, network device 120 can instruct terminal device 110 whether to use a traditional MCS table or an enhanced MCS table to apply the MCS index via a new information element (IE) "PUSCH-MCS table". For example, if network device 120 determines that the received preamble was selected from a second preamble pool, then network device 120 knows that terminal device 110 only supports legacy constellations. Network device 120 can configure PUSCH-MCS table = 0 to instruct terminal device 110 to select an MCS from the legacy MCS table. If network device 120 determines that the received preamble was selected from a first preamble pool, then network device 120 knows that terminal device 110 supports both legacy and custom constellations. Network device 120 can configure PUSCH-MCS table = 0 or PUSCH-MCS table = 1 to instruct terminal device 110 to select an MCS from either the legacy MCS table or the enhanced MCS table.

[0076] At 705A, network device 120 sends Msg2 with UL authorization to terminal device 110 as a random access response. Msg2 may include an index to the new MCS table, as well as entries in the new MCS table. Terminal device 110 receives Msg2 and implements the UL transmission. For example, terminal device 110 sends Msg3 to network device 120 on the PUSCH (707A). Msg3 may include the UL payload of terminal device 110. Network device 120 receives Msg3 from terminal device 110 and uses an AI receiver to demap the received signal based on a custom constellation (709A). If network device 120 correctly receives the transmission, then RA is finalized. If the transmission conflicts with the UL transmission of another terminal device 110, network device 120 may send Msg4 to terminal device 110 for contention resolution purposes (711A).

[0077] Figure 7B Signaling flow 700B of an example four-step CFRA procedure for supporting custom constellations according to some example embodiments of this disclosure is shown. For example... Figure 7BAs shown, signaling flow 700B involves terminal device 110 and network device 120. Signaling flow 700B can be another example of signaling flow 600.

[0078] In some cases, network device 120 may not know in advance whether terminal device 110 supports a custom constellation. At 701B, network device 120 can configure or assign two preambles to terminal device 110, for example, preamble 1 from a traditional preamble pool (i.e., the second preamble group as described above) and preamble 2 from a new preamble pool (i.e., the first preamble group as described above). At 703B, terminal device 110 can generate a preamble and then select one from the two preambles to implicitly indicate support for a custom constellation (or conversely, lack of support for a custom constellation). For example, if terminal device 110 determines that it only supports traditional constellations (e.g., QAM constellations), it can choose preamble 1. If terminal device 110 determines that it supports both QAM constellations and custom constellations, it can choose preamble 2.

[0079] At 705B, terminal device 110 sends the selected preamble to network device 120 in Msg1. Network device 120 receives the preamble from terminal device 110. Based on the received preamble, network device 120 can configure UL authorization. Network device 120 instructs terminal device 110 via a new IE, "PUSCH-MCS table," whether to use the traditional MCS table or the enhanced MCS table to apply the MCS index. For example, network device 120 can configure PUSCH-MCS table=0 to instruct terminal device 110 to select an MCS from the traditional MCS table. Alternatively, network device 120 can configure PUSCH-MCS table=0 or PUSCH-MCS table=1 to instruct terminal device 110 to select an MCS from either the traditional or enhanced MCS table. At 707B, network device 120 sends Msg2 with UL authorization to terminal device 110 as a random access response. As an example, Msg2 may include an MCS table index corresponding to the new MCS table, and an entry in the new MCS table for Msg3. Terminal device 110 receives Msg2 and performs UL transmission. For example, terminal device 110 sends Msg3 to network device 120 on the PUSCH (709B). Network device 120 receives Msg3 from terminal device 110 and uses an AI receiver to demap the received signal based on a custom constellation (711B).

[0080] Figure 8 An example signaling flow 800 for a two-step random access procedure supporting a custom constellation according to some example embodiments of this disclosure is shown. Reference will be made to this document for discussion purposes. Figure 1 Discuss signaling flow 800. For example... Figure 8As shown, signaling flow 800 involves terminal device 110 and network device 120.

[0081] Terminal device 110 selects (801) a first preamble indicating support for a custom constellation. Step 801 can be similar to... Figure 6 Step 601 in the document, and the details will not be repeated here.

[0082] In some example embodiments, terminal device 110 may receive configuration from network device 120 for a first preamble from a first preamble group indicating support for a custom constellation. For example, in some cases, if terminal device 110 supports a custom constellation, it may select the first preamble. If terminal device 110 does not support a custom constellation, it may select the second preamble from a second preamble from a second preamble group indicating lack of support for a custom constellation. Alternatively, terminal device 110 may receive configuration for a first preamble from the first preamble group and a second preamble from the second preamble group indicating lack of support for a custom constellation. For example, network device 120 may send two preambles to terminal device 110: one indicating support for a custom constellation (e.g., preamble A) and another indicating lack of support for a custom constellation (e.g., preamble B). Terminal device 110 may receive both preambles. During a random access procedure, if terminal device 110 supports a custom constellation, it may select preamble A. If terminal device 110 does not support a custom constellation, it can choose preamble B. Refer to the above embodiments for details, which will not be repeated here.

[0083] Terminal device 110 sends (803) a first preamble, uplink data, and an indication (referred to as the first indication) to network device 120 to initiate a random access procedure with network device 120. The MCS may correspond to a custom constellation. In some example embodiments, the first indication may also indicate a first MCS table from which the first MCS is selected. The first MCS table may include at least one MCS corresponding to the custom constellation. Network device 120 receives (805) the first preamble, uplink data, and the first indication from terminal device 110. Based on the first preamble, network device 120 can determine that terminal device 110 supports the custom constellation. Based on this determination and the first indication, network device 120 can determine the first MCS and then decode the uplink data based on the determined first MCS.

[0084] Alternatively, in some cases, if terminal device 110 fails to support the customized constellation, it may select a second preamble. Terminal device 110 may send the second preamble, uplink data, and an indication (referred to as the second indication) to network device 120 to indicate a second MCS applied to the uplink data, in order to initiate a random access procedure with network device 120. The second indication may also indicate a second MCS table from which the second MCS is selected. The second MCS table may not include the MCS corresponding to the customized constellation. Network device 120 may receive the second preamble, uplink data, and second indication from terminal device 110. Based on the second preamble, network device 120 may determine that terminal device 110 fails to support the customized constellation. Based on this determination and the second indication, network device 120 may determine the second MCS and then decode the uplink data based on the determined second MCS.

[0085] In some example embodiments, the first preamble, uplink data, and indication may be included in message A of the random access procedure sent to network device 120. For example, the first preamble, uplink data, and indication may be included in MsgA of a two-step RACH procedure.

[0086] Network device 120 sends (807) a first response to the first preamble and uplink data to terminal device 110. Terminal device 110 receives (809) the first response from network device 120. As an example, if the random access procedure is a CBRA procedure, the first response may include contention resolution information. In some example embodiments, the first response may be included in message B of the random access procedure received from network device 120. For example, the first response may be included in MsgB of a two-step RACH procedure.

[0087] Figure 9A Signaling flow 900A of another example CBRA procedure supporting custom constellations according to some example embodiments of this disclosure is shown. For example... Figure 9A As shown, signaling flow 900A involves terminal device 110 and network device 120. Signaling flow 900A can be an example of signaling flow 800.

[0088] like Figure 9AAs shown, terminal device 110 begins by selecting a preamble from one of two preamble pools. Terminal device 110 then sends (901A) MsgA to network device 120, which includes: the selected preamble; a PUSCH payload with an MCS index pointing to an MCS table indicated via the selected preamble. The selected preamble indicates to network device 120 which MCS table should be used to decode the PUSCH. Network device 120 receives MsgA from terminal device 110. Based on MsgA, network device 120 responds with MsgB and sends MsgB to terminal device 110 (903A). For example, MsgB may include a contention resolution message.

[0089] Figure 9B Signaling flow 900B of another example CFRA procedure supporting a custom constellation according to some example embodiments of this disclosure is shown. For example... Figure 9B As shown, signaling flow 900B involves terminal device 110 and network device 120. Signaling flow 900B can be another example of signaling flow 800.

[0090] For the CFRA process, network device 120 can configure or assign the corresponding preamble to terminal device 110. If network device 120 does not know in advance whether terminal device 110 supports a custom constellation, network device 120 can configure or assign (901B) two preambles to terminal device 110: one preamble from the traditional preamble pool (i.e., the second preamble group as described above), and one preamble from the new preamble pool (i.e., the first preamble group as described above). Network device 120 can also configure PUSCH, including a first MCS index corresponding to the traditional MCS table and a second MCS index corresponding to the enhanced MCS table.

[0091] Terminal device 110 selects a preamble from one of two preconfigured preambles. Then, terminal device 110 sends (903B) MsgA to network device 120. MsgA includes: the selected preamble; a PUSCH payload with an MCS index pointing to an MCS table indicated via the selected preamble. The selected preamble implicitly indicates to network device 120 which MCS table should be used to decode the PUSCH. Network device 120 receives MsgA from terminal device 110. Based on MsgA, network device 120 can respond with a random access response message. Network device 120 sends MsgB to terminal device 110 (905B).

[0092] Figure 10A A flowchart of an example method 1000A implemented at a first device according to some example embodiments of the present disclosure is shown. For the purposes of discussion, [the following will be discussed]. Figure 1 Angle description method 1000A for terminal device 110 in the middle.

[0093] At frame 1010, terminal device 110 selects a first preamble that indicates the first device's support for a custom constellation.

[0094] At box 1020, terminal device 110 sends a first preamble to network device to initiate a random access procedure with network device.

[0095] At box 1030, terminal device 110 receives from network device an instruction indicating the selection of modulation and coding scheme (MCS).

[0096] At box 1040, terminal device 110 sends uplink data to network device based on MCS.

[0097] In some example embodiments, method 1000A further includes: receiving from a network device a configuration for a first preamble from a first preamble group indicating support for a custom constellation, or receiving from a network device a configuration for a first preamble from a first preamble group indicating support for a custom constellation and a second preamble from a second preamble group indicating non-support for a custom constellation.

[0098] In some example embodiments, this configuration is received via system information or dedicated signaling.

[0099] In some example embodiments, method 1000A further includes: if it is determined that the first device supports a custom constellation, selecting a first preamble based on configuration; and sending the first preamble to the network device for initiating a random access procedure with the network device.

[0100] In some example embodiments, method 1000A further includes: if it is determined that the first device fails to support a custom constellation, selecting a second preamble based on configuration, and sending the second preamble to the network device for initiating a random access procedure with the network device.

[0101] In some example embodiments, the preamble in the first preamble group is generated based on the length of a first root sequence used to generate the first preamble group, and the preamble in the second preamble group is generated based on the length of a second root sequence used to generate the second preamble group, and the first root sequence is different from the second root sequence.

[0102] In some example embodiments, method 1000A further includes receiving from a network device an indication of selecting an MCS from a first MCS table or a second MCS table, wherein the first MCS table includes at least one MCS corresponding to a custom constellation, and the second MCS table includes MCSs not corresponding to a custom constellation.

[0103] In some example embodiments, the random access procedure is a contention-based random access procedure or a contention-free random access procedure.

[0104] In some example embodiments, a first preamble is included in a first message of a random access procedure sent to the network device, and an indication is included in a second message of a random access procedure received from the network device, and uplink data is included in a third message of a random access procedure sent to the network device.

[0105] In some example embodiments, the first device is a terminal device or is included in a terminal device.

[0106] Figure 10B A flowchart of an example method 1000B implemented at a second device according to some example embodiments of the present disclosure is shown. For the purposes of discussion, [the following will be discussed]. Figure 1 Method 1000B describes the network device 120 from the perspective of network device 120.

[0107] At box 1050, network device 120 receives from terminal device a first preamble for initiating a random access procedure with the second device, the first preamble indicating terminal device support for a custom constellation.

[0108] At box 1060, network device 120 sends an instruction to terminal device to indicate the selection of modulation and coding scheme (MCS).

[0109] At box 1070, network device 120 receives uplink data sent based on MCS from terminal device.

[0110] In some example embodiments, method 1000B further includes: determining, based on a first preamble, that the terminal device supports a custom constellation; and determining, based on the determination, an MCS for the terminal device.

[0111] In some example embodiments, the random access procedure is a contention-based random access procedure or a contention-free random access procedure.

[0112] In some example embodiments, method 1000B further includes: sending to the terminal device a configuration for a first preamble from a first preamble group indicating support for a custom constellation, or sending to the terminal device a configuration for a first preamble from a first preamble group indicating support for a custom constellation and a second preamble from a second preamble group indicating non-support for a custom constellation.

[0113] In some example embodiments, the configuration is sent via system information or dedicated signaling.

[0114] In some example embodiments, the preamble in the first preamble group is generated based on the length of a first root sequence used to generate the first preamble group, and the preamble in the second preamble group is generated based on the length of a second root sequence used to generate the second preamble group, and the first root sequence is different from the second root sequence.

[0115] In some example embodiments, method 1000B further includes sending an instruction to a terminal device to indicate the selection of an MCS from a first MCS table or a second MCS table, wherein the first MCS table includes at least one MCS corresponding to a customized constellation, and the second MCS table includes MCSs that do not correspond to a customized constellation.

[0116] In some example embodiments, a first preamble is included in a first message of a random access procedure sent to the network device, and an indication is included in a second message of a random access procedure received from the network device, and uplink data is included in a third message of a random access procedure sent to the network device.

[0117] In some example embodiments, a first means capable of performing any of the methods in method 1000A (e.g., Figure 1 The terminal device 110 may include components for performing corresponding operations of method 1000A. These components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module. The first device may be implemented as or included in... Figure 1 In terminal device 110.

[0118] In some example embodiments, the first device includes: components for selecting a first preamble indicating the first device's support for a custom constellation; components for sending the first preamble to a network device to initiate a random access procedure with the network device; components for receiving from the network device an indication of the selection of a modulation and coding scheme (MCS); and components for sending uplink data to the network device based on the MCS.

[0119] In some example embodiments, the first device further includes components for: receiving from the network device a configuration of a first preamble from a first preamble group for indicating support for a custom constellation, or receiving from the network device a configuration of a first preamble from the first preamble group for indicating support for a custom constellation and a second preamble from a second preamble group for indicating non-support for a custom constellation.

[0120] In some example embodiments, this configuration is received via system information or dedicated signaling.

[0121] In some example embodiments, the first device further includes: a component for selecting a first preamble based on a configuration if it is determined that the first device supports a custom constellation; and a component for sending the first preamble to a network device for initiating a random access procedure with the network device.

[0122] In some example embodiments, the first device further includes: components for selecting a second preamble based on configuration if it is determined that the first device fails to support a custom constellation, and components for sending the second preamble to a network device for initiating a random access procedure with the network device.

[0123] In some example embodiments, the preamble in the first preamble group is generated based on the length of a first root sequence used to generate the first preamble group, and the preamble in the second preamble group is generated based on the length of a second root sequence used to generate the second preamble group, and the first root sequence is different from the second root sequence.

[0124] In some example embodiments, the first apparatus further includes: a component for receiving from a network device an indication of selecting an MCS from a first MCS table or a second MCS table, wherein the first MCS table includes at least one MCS corresponding to a custom constellation, and the second MCS table includes MCSs not corresponding to a custom constellation.

[0125] In some example embodiments, the random access procedure is a contention-based random access procedure or a contention-free random access procedure.

[0126] In some example embodiments, a first preamble is included in a first message of a random access procedure sent to the network device, and an indication is included in a second message of a random access procedure received from the network device, and uplink data is included in a third message of a random access procedure sent to the network device.

[0127] In some example embodiments, the first device is a terminal device or is included in a terminal device.

[0128] In some example embodiments, a second device capable of performing any method 1000B (e.g., Figure 1 The network device 120 may include components for performing corresponding operations of method 1000B. These components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module. The second device may be implemented as or included in... Figure 1 Among the network devices in 120.

[0129] In some example embodiments, the second apparatus includes: components for receiving from a terminal device a first preamble for initiating a random access procedure with the second apparatus, the first preamble indicating that the terminal device supports a custom constellation; components for sending to the terminal device an indication of a modulation and coding scheme (MCS); and components for receiving uplink data transmitted from the terminal device based on the MCS.

[0130] In some example embodiments, the second device further includes: components for determining, based on the first preamble, that the terminal device supports a custom constellation; and components for determining, based on the determination, the MCS for the terminal device.

[0131] In some example embodiments, the random access procedure is a contention-based random access procedure or a contention-free random access procedure.

[0132] In some example embodiments, the second device further includes components for: sending to the terminal device a configuration of a first preamble from a first preamble group indicating support for a custom constellation, or sending to the terminal device a configuration of a first preamble from a first preamble group indicating support for a custom constellation and a second preamble from a second preamble group indicating non-support for a custom constellation.

[0133] In some example embodiments, the configuration is sent via system information or dedicated signaling.

[0134] In some example embodiments, the preamble in the first preamble group is generated based on the length of a first root sequence used to generate the first preamble group, and the preamble in the second preamble group is generated based on the length of a second root sequence used to generate the second preamble group, and the first root sequence is different from the second root sequence.

[0135] In some example embodiments, the second apparatus further includes: a component for sending to a terminal device an indication of selecting an MCS from a first MCS table or a second MCS table, wherein the first MCS table includes at least one MCS corresponding to a customized constellation, and the second MCS table includes MCSs not corresponding to a customized constellation.

[0136] In some example embodiments, a first preamble is included in a first message of a random access procedure sent to the network device, and an indication is included in a second message of a random access procedure received from the network device, and uplink data is included in a third message of a random access procedure sent to the network device.

[0137] Figure 11A A flowchart of an example method 1100A implemented at a first device according to some example embodiments of the present disclosure is shown. For the purposes of discussion, [the following will be discussed]. Figure 1 Angle description method 1100A for terminal device 110 in the middle.

[0138] At frame 1110, terminal device 110 selects a first preamble that indicates the first device's support for a custom constellation.

[0139] At box 1120, terminal device 110 sends a first preamble, uplink data, and an indication of a first modulation and coding scheme (MCS) applied to the uplink data to network device to initiate a random access procedure with network device, wherein the MCS corresponds to a custom constellation.

[0140] At box 1130, terminal device 110 receives a first response from network device to the first preamble and uplink data.

[0141] In some example embodiments, the instruction is also used to instruct a first MCS table from which a first MCS is selected, the first MCS table including at least one MCS corresponding to a custom constellation.

[0142] In some example embodiments, method 1100A further includes: receiving from a network device a configuration of a first preamble from a first preamble group indicating support for a custom constellation, or receiving from a network device a configuration of a first preamble from a first preamble group indicating support for a custom constellation and a second preamble from a second preamble group indicating non-support for a custom constellation.

[0143] In some example embodiments, this configuration is received via system information or dedicated signaling.

[0144] In some example embodiments, method 1100A further includes: selecting a first preamble based on configuration if it is determined that the first device supports a custom constellation; and sending the first preamble, uplink data, and an indication for indicating a first MCS applied to the uplink data to the network device to initiate a random access procedure with the network device.

[0145] In some example embodiments, method 1100A further includes: if it is determined that the first device fails to support a custom constellation, selecting a second preamble based on configuration, and sending the second preamble, uplink data, and an indication for indicating a second MCS applied to the uplink data to the network device to initiate a random access procedure with the network device.

[0146] In some example embodiments, the preamble in the first preamble group is generated based on the length of a first root sequence used to generate the first preamble group, and the preamble in the second preamble group is generated based on the length of a second root sequence used to generate the second preamble group, and the first root sequence is different from the second root sequence.

[0147] In some example embodiments, the random access procedure is a contention-based random access procedure or a contention-free random access procedure.

[0148] In some example embodiments, a first preamble, uplink data, and indication are included in message A of a random access procedure sent to the network device, and a first response is included in message B of a random access procedure received from the network device.

[0149] In some example embodiments, the first device is a terminal device or is included in a terminal device.

[0150] Figure 11B A flowchart of an example method 1100B implemented at a second device according to some example embodiments of the present disclosure is shown. For the purposes of discussion, [the following will be discussed]. Figure 1 Method 1100B describes the network device 120 from the perspective of the network device 120.

[0151] At box 1140, network device 120 receives from terminal device a first preamble indicating support for a custom constellation by the first device, uplink data, and an indication of a first modulation and coding scheme (MCS) applied to the uplink data, wherein the MCS corresponds to the custom constellation.

[0152] At frame 1150, network device 120 sends a first response to the terminal device for the first preamble and uplink data.

[0153] In some example embodiments, the instruction is also used to indicate a first MCS table from which a first MCS is selected, the first MCS table including at least one MCS corresponding to a custom constellation.

[0154] In some example embodiments, method 1100B further includes: determining that the terminal device supports a custom constellation based on a first preamble; determining a first MCS based on determination and indication; and decoding uplink data based on the determined first MCS.

[0155] In some example embodiments, method 1100B further includes sending to the terminal device a configuration for a first preamble from a first preamble group indicating support for a custom constellation, or sending to the terminal device a configuration for a first preamble from a first preamble group indicating support for a custom constellation and a second preamble from a second preamble group indicating non-support for a custom constellation.

[0156] In some example embodiments, the preamble in the first preamble group is generated based on the length of a first root sequence used to generate the first preamble group, and the preamble in the second preamble group is generated based on the length of a second root sequence used to generate the second preamble group, and the first root sequence is different from the second root sequence.

[0157] In some example embodiments, a first preamble, uplink data, and indication are included in message A of a random access procedure sent to the network device, and a first response is included in message B of a random access procedure received from the network device.

[0158] In some example embodiments, a first means capable of performing any of the methods 1100A (e.g., Figure 1 The terminal device 110 may include components for performing the corresponding operations of method 1100A. These components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module. The first device may be implemented as or included in... Figure 1 In terminal device 110.

[0159] In some example embodiments, the first apparatus includes: components for selecting a first preamble indicating the first apparatus's support for a custom constellation; components for sending the first preamble, uplink data, and an indication of a first modulation and coding scheme (MCS) applied to the uplink data to a network device to initiate a random access procedure with the network device, wherein the MCS corresponds to the custom constellation; and components for receiving a first response from the network device to the first preamble and uplink data.

[0160] In some example embodiments, the instruction is also used to instruct a first MCS table from which a first MCS is selected, the first MCS table including at least one MCS corresponding to a custom constellation.

[0161] In some example embodiments, the first device further includes components for: receiving from the network device a configuration of a first preamble from a first preamble group for indicating support for a custom constellation, or receiving from the network device a configuration of a first preamble from the first preamble group for indicating support for a custom constellation and a second preamble from a second preamble group for indicating non-support for a custom constellation.

[0162] In some example embodiments, this configuration is received via system information or dedicated signaling.

[0163] In some example embodiments, the first apparatus further includes: a component for selecting a first preamble based on a configuration if it is determined that the first apparatus supports a custom constellation; and a component for sending the first preamble, uplink data, and an indication for indicating a first MCS applied to the uplink data to initiate a random access procedure with the network device.

[0164] In some example embodiments, the first device further includes: components for selecting a second preamble based on configuration if it is determined that the first device fails to support a custom constellation, and components for sending the second preamble, uplink data, and an indication for indicating a second MCS applied to the uplink data to initiate a random access procedure with the network device.

[0165] In some example embodiments, the preamble in the first preamble group is generated based on the length of a first root sequence used to generate the first preamble group, and the preamble in the second preamble group is generated based on the length of a second root sequence used to generate the second preamble group, and the first root sequence is different from the second root sequence.

[0166] In some example embodiments, the random access procedure is a contention-based random access procedure or a contention-free random access procedure.

[0167] In some example embodiments, a first preamble, uplink data, and indication are included in message A of a random access procedure sent to the network device, and a first response is included in message B of a random access procedure received from the network device.

[0168] In some example embodiments, the first device is a terminal device or is included in a terminal device.

[0169] In some example embodiments, a second device capable of performing any method 1100B (e.g., Figure 1The network device 120 may include components for performing corresponding operations of method 1100B. These components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module. The second device may be implemented as or included in... Figure 1 Among the network devices in 120.

[0170] In some example embodiments, the second apparatus includes: components for receiving from a terminal device a first preamble indicating support of the first apparatus for a custom constellation, uplink data, and an indication of a first modulation and coding scheme (MCS) applied to the uplink data, wherein the MCS corresponds to the custom constellation; and components for sending a first response to the first preamble and uplink data to the terminal device.

[0171] In some example embodiments, the instruction is also used to indicate a first MCS table from which a first MCS is selected, the first MCS table including at least one MCS corresponding to a custom constellation.

[0172] In some example embodiments, the second apparatus further includes: components for determining, based on a first preamble, that the terminal device supports a custom constellation; components for determining, based on determination and indication, a first MCS; and components for decoding uplink data based on the determined first MCS.

[0173] In some example embodiments, the second device further includes components for: sending to the terminal device a configuration of a first preamble from a first preamble group indicating support for a custom constellation, or sending to the terminal device a configuration of a first preamble from a first preamble group indicating support for a custom constellation and a second preamble from a second preamble group indicating non-support for a custom constellation.

[0174] In some example embodiments, the preamble in the first preamble group is generated based on the length of a first root sequence used to generate the first preamble group, and the preamble in the second preamble group is generated based on the length of a second root sequence used to generate the second preamble group, and the first root sequence is different from the second root sequence.

[0175] In some example embodiments, a first preamble, uplink data, and indication are included in message A of a random access procedure sent to the network device, and a first response is included in message B of a random access procedure received from the network device.

[0176] Figure 12 This is a simplified block diagram of a device 1200 suitable for implementing an example embodiment of the present disclosure. The device 1200 can be provided to implement a communication device, such as... Figure 1The terminal device 110 or network device 120 shown. As shown, device 1200 includes one or more processors 1210, one or more memories 1220 coupled to processor 1210, and one or more communication modules 1240 coupled to processor 1210.

[0177] Communication module 1240 is used for bidirectional communication. Communication module 1240 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interface can represent any interface required for communication with other network elements. In some example embodiments, communication module 1240 may include at least one antenna.

[0178] As a non-limiting example, processor 1210 can be any type suitable for a local technology network and can include one or more of the following: general-purpose computer, special-purpose computer, microprocessor, digital signal processor (DSP), and processor based on a multi-core processor architecture. Device 1200 can have multiple processors, such as application-specific integrated circuit chips that are time-dependent on a clock of a synchronous main processor.

[0179] Memory 1220 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 1224, electrically programmable read-only memory (EPROM), flash memory, hard disk, optical disc (CD), digital video disc (DVD), optical disc, laser disc, and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 1222 and other volatile memories that will not persist during power-off periods.

[0180] Computer program 1230 includes computer-executable instructions that are executed by an associated processor 1210. The instructions of program 1230 may include instructions for performing operations / actions of some example embodiments of this disclosure. Program 1230 may be stored in memory (e.g., ROM 1224). Processor 1210 can perform any suitable actions and processes by loading program 1230 into RAM 1222.

[0181] The exemplary embodiments of this disclosure can be implemented by program 1230, enabling device 1200 to execute as described in the reference. Figures 6 to 11B Any process discussed in this disclosure. Exemplary embodiments of this disclosure may also be implemented by hardware or by a combination of software and hardware.

[0182] In some example embodiments, program 1230 may be tangibly contained in a computer-readable medium, which may be included in device 1200 (such as memory 1220) or other storage device accessible by device 1200. Device 1200 may load program 1230 from the computer-readable medium into RAM 1222 for execution. In some example embodiments, the computer-readable medium may include any type of non-transitory storage medium, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. As used herein, the term "non-transitory" is a limitation on the medium itself (i.e., tangible, not tactile), rather than a limitation on the persistence of data storage (e.g., RAM versus ROM).

[0183] Figure 13 An example of a computer-readable medium 1300 is shown, which may be in the form of a CD, DVD, or other optical storage disc. A program 1230 is stored on the computer-readable medium 1300.

[0184] Generally, the various embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects can be implemented in hardware, while others can be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of this disclosure are illustrated and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, as non-limiting examples, the blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0185] Some exemplary embodiments of this disclosure also provide at least one computer program product tangibly stored on a computer-readable medium, such as a non-transitory computer-readable medium. The computer program product includes computer-executable instructions that execute in a device on a target entity or virtual processor, such as those included in a program module, to perform any of the methods described above. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform a particular task or implement a particular abstract data type. In various embodiments, the functionality of a program module can be combined or split among program modules as needed. The machine-executable instructions for a program module can execute within a local or distributed device. In a distributed device, the program module can reside in both local and remote storage media.

[0186] Program code used to perform the methods of this disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0187] In the context of this disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, etc.

[0188] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof. More specific examples of computer-readable storage media will include electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0189] Furthermore, although operations are described in a specific order, this should not be construed as requiring that such operations be performed in the specific order shown or sequentially, or that all shown operations be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the discussion above, these details should not be construed as limiting the scope of this disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated otherwise, certain features described in the context of a single embodiment may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated otherwise, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0190] Although this disclosure has been described in language specific to structural features and / or methodological actions, it should be understood that the disclosure as defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as exemplary forms for implementing the claims.

[0191] Furthermore, the various implementations of this disclosure can be described with reference to the following terms, and their features can be combined in any reasonable manner.

[0192] Clause 1. A first apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to at least: select a first preamble, the first preamble indicating support for a custom constellation by the first apparatus; send the first preamble to a network device for initiating a random access procedure with the network device; receive from the network device an indication for selecting a modulation and coding scheme (MCS); and send uplink data to the network device based on the MCS.

[0193] Clause 2. The first apparatus according to Clause 1, wherein the first apparatus is further configured to: receive from the network device a configuration of a first preamble from a first preamble group indicating support for the custom constellation, or receive from the network device a configuration of the first preamble from the first preamble group indicating support for the custom constellation and a second preamble from a second preamble group indicating non-support for the custom constellation.

[0194] Clause 3. The first device as described in Clause 2, wherein the configuration is received via system information or dedicated signaling.

[0195] Clause 4. The first apparatus according to Clause 2 or 3, wherein the first apparatus is further configured to: select the first preamble based on the configuration if it is determined that the first apparatus supports the custom constellation; and send the first preamble to the network device for initiating the random access procedure with the network device.

[0196] Clause 5. The first device according to Clause 2 or 3, wherein the first device is further configured to: if it is determined that the first device fails to support the customized constellation, select the second preamble based on the configuration, and send the second preamble to the network device for initiating the random access procedure with the network device.

[0197] Clause 6. The first apparatus according to any one of Clauses 2 to 5, wherein the preamble in the first preamble group is generated based on the length of a first root sequence used to generate the first preamble group, and wherein the preamble in the second preamble group is generated based on the length of a second root sequence used to generate the second preamble group, and wherein the first root sequence is different from the second root sequence.

[0198] Clause 7. A first device according to any one of Clauses 2 to 6, wherein the first device is configured to: receive from the network device an instruction indicating the selection of an MCS from a first MCS table or a second MCS table, wherein the first MCS table includes at least one MCS corresponding to the customized constellation, and the second MCS table includes MCSs not corresponding to the customized constellation.

[0199] Clause 8. The first apparatus according to any one of Clauses 1 to 7, wherein the random access procedure is a contention-based random access procedure or a contention-free random access procedure.

[0200] Clause 9. The first apparatus according to any one of Clauses 1 to 8, wherein the first preamble is included in a first message of the random access procedure sent to the network device, wherein the indication is included in a second message of the random access procedure received from the network device, and wherein the uplink data is included in a third message of the random access procedure sent to the network device.

[0201] Clause 10. The first device according to any one of Clauses 1 to 9, wherein the first device is a terminal device or is included in a terminal device.

[0202] Clause 11. A second apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the second apparatus to at least: receive from a terminal device a first preamble for initiating a random access procedure with the second apparatus, the first preamble indicating support of a custom constellation by the terminal device; send to the terminal device an indication for selecting a modulation and coding scheme (MCS); and receive from the terminal device uplink data transmitted based on the MCS.

[0203] Clause 12. The second means according to Clause 11, wherein the second means is configured to: determine, based on the first preamble, that the terminal device supports the custom constellation; and determine, based on the determination, the MCS for the terminal device.

[0204] Clause 13. The second apparatus according to Clause 11 or 12, wherein the random access procedure is a contention-based random access procedure or a contention-free random access procedure.

[0205] Clause 14. The second apparatus according to Clause 11 or 12, wherein the second apparatus is further configured to: send to the terminal device a configuration of a first preamble from a first preamble group indicating support for the custom constellation, or send to the terminal device a configuration of the first preamble from a first preamble group indicating support for the custom constellation and a second preamble from a second preamble group indicating non-support for the custom constellation.

[0206] Clause 15. The second device as described in Clause 14, wherein the configuration is transmitted via system information or dedicated signaling.

[0207] Clause 16. The second apparatus according to Clause 14, wherein the preamble in the first preamble group is generated based on the length of a first root sequence used to generate the first preamble group, and wherein the preamble in the second preamble group is generated based on the length of a second root sequence used to generate the second preamble group, and wherein the first root sequence is different from the second root sequence.

[0208] Clause 17. The second means according to Clause 12 or 14, wherein the second means is configured to: send to the terminal device the instruction for indicating the selection of the MCS from a first MCS table or a second MCS table, wherein the first MCS table includes at least one MCS corresponding to the customized constellation, and the second MCS table includes MCSs not corresponding to the customized constellation.

[0209] Clause 18. The second apparatus according to any one of Clauses 11 to 17, wherein the first preamble is included in a first message of the random access procedure sent to the network device, wherein the indication is included in a second message of the random access procedure received from the network device, and wherein the uplink data is included in a third message of the random access procedure sent to the network device.

[0210] Clause 19. A method comprising: selecting a first preamble, the first preamble indicating support for a custom constellation by a first device; sending the first preamble to a network device for initiating a random access procedure with the network device; receiving from the network device an indication for selecting a modulation and coding scheme (MCS); and sending uplink data to the network device based on the MCS.

[0211] Clause 20. A method comprising: receiving from a terminal device a first preamble for initiating a random access procedure with a second device, the first preamble indicating that the terminal device supports a custom constellation; sending to the terminal device an indication for selecting a modulation and coding scheme (MCS); and receiving from the terminal device uplink data transmitted based on the MCS.

[0212] Clause 21. A first apparatus comprising: means for selecting a first preamble indicating support of the first apparatus for a custom constellation; means for sending the first preamble to a network device for initiating a random access procedure with the network device; means for receiving from the network device an indication of selection of a modulation and coding scheme (MCS); and means for sending uplink data to the network device based on the MCS.

[0213] Clause 22. A second apparatus comprising: means for receiving from a terminal device a first preamble for initiating a random access procedure with the second apparatus, the first preamble indicating that the terminal device supports a custom constellation; means for sending to the terminal device an indication of selection of a modulation and coding scheme (MCS); and means for receiving from the terminal device uplink data transmitted based on the MCS.

[0214] Clause 23. A computer-readable medium comprising instructions stored thereon for causing a device to perform at least the method described in Clause 19 or the method described in Clause 20.

Claims

1. A first device for communication, comprising: At least one processor; as well as At least one memory stores instructions that, when executed by the at least one processor, cause the first device to at least: Select a first preamble, which indicates that the first device supports a custom constellation; Send the first preamble to the network device to initiate a random access procedure with the network device; Receive from the network device an instruction indicating the selection of a modulation and coding scheme (MCS); and Based on the MCS, uplink data is sent to the network device.

2. The first device according to claim 1, wherein the first device is further configured to: The network device receives configuration for a first preamble from a first preamble group indicating support for the custom constellation, or receives configuration for the following: a first preamble from a first preamble group indicating support for the custom constellation and a second preamble from a second preamble group indicating non-support for the custom constellation.

3. The first apparatus according to claim 2, wherein the configuration is received via system information or dedicated signaling.

4. The first device according to claim 2 or 3, wherein the first device is further configured to: If it is determined that the first device supports the customized constellation, then the first preamble is selected based on the configuration; and The first preamble is sent to the network device to initiate the random access procedure with the network device.

5. The first device according to claim 2 or 3, wherein the first device is further configured to: If it is determined that the first device fails to support the customized constellation, then the second preamble is selected based on the configuration, and The second preamble is sent to the network device to initiate the random access procedure with the network device.

6. The first apparatus according to claim 2 or 3, wherein the preamble in the first preamble group is generated based on the length of a first root sequence, the first root sequence being used to generate the first preamble group, and wherein the preamble in the second preamble group is generated based on the length of a second root sequence, the second root sequence being used to generate the second preamble group, and The first root sequence is different from the second root sequence.

7. The first device according to claim 2 or 3, wherein the first device is configured to: Receive from the network device the instruction indicating the selection of the MCS from the first MCS table or the second MCS table. The first MCS table includes at least one MCS corresponding to the customized constellation, and the second MCS table includes MCSs that do not correspond to the customized constellation.

8. The first apparatus according to any one of claims 1 to 3, wherein the random access procedure is a contention-based random access procedure or a contention-free random access procedure.

9. The first apparatus according to any one of claims 1 to 3, wherein the first preamble is included in the first message of the random access procedure sent to the network device, and The indication is included in the second message of the random access procedure received from the network device, and The uplink data is included in a third message of the random access procedure sent to the network device.

10. The first device according to any one of claims 1 to 3, wherein the first device is a terminal device or is included in a terminal device.

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