Bandwidth fraction selection for random access procedures.

Abstract

An example embodiment of the present disclosure relates to bandwidth portion selection for a random access procedure. According to an embodiment of the present disclosure, a terminal device receives configuration information from a network device. The configuration information indicates a set of BWPs and a configuration of the set of BWPs. When a random access procedure is triggered for a certain combination of characteristics, the terminal device determines whether a condition for switching to a target BWP is met. If the condition is met, the terminal device switches to the target BWP. In this way, resource efficiency is improved.

Description

[Technical field]

[0001] TECHNICAL FIELD Embodiments of the present disclosure relate generally to the field of telecommunications, and in particular to a method, device, apparatus, and computer-readable storage medium for selecting a bandwidth portion (BWP) for a random access procedure. [Background technology]

[0002] With the development of communication systems, more and more technologies are proposed. A physical random access channel (PRACH) is a shared channel used by terminal devices to access a mobile network for cell setup and burst data transmission. To access the PRACH, a terminal device may initiate a random access procedure. Furthermore, a terminal device may be configured with one or more bandwidth parts (BWPs). A bandwidth part (BWP) is a contiguous set of physical resource blocks (PRBs) on a particular carrier. These RBs are selected from a contiguous subset of common resource blocks for a particular numerology. Summary of the Invention

[0003] Generally, the example embodiments of the present disclosure provide a solution for determining a BWP for a random access procedure.

[0004] In a first aspect, a first device is provided, the first device including at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to cause, using the at least one processor, the first device to: receive configuration information from a second device indicating a set of Bandwidth Parts (BWPs) and a set of Random Access Channel (RACH) configurations for the set of BWPs, determine at the first device that a random access procedure is triggered based on the at least one characteristic, determine based on the set of RACH configurations whether a condition is met for switching to a target BWP, the target BWP being configured with RACH resources for the at least one characteristic, and perform random access with the second device on the target BWP according to a determination that the condition is met.

[0005] In a second aspect, a second device is provided, the second device including at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to cause, with the at least one processor, the second device to send configuration information to the first device indicating a set of Bandwidth Parts (BWPs) and a set of Random Access Channel (RACH) configurations for the set of BWPs, and to perform a random access with the first device on a target BWP, the random access procedure being triggered based on the at least one characteristic, the target BWP being configured with RACH resources for the at least one characteristic.

[0006] In a third aspect, a method is provided, the method including: receiving, at a first device, configuration information from a second device indicating a set of bandwidth portions (BWPs) and a set of random access channel (RACH) configurations of the set of BWPs; determining, at the first device, that a random access procedure is triggered based on at least one characteristic; determining, based on the set of RACH configurations, whether a condition is met for switching to a target BWP, the target BWP being configured with RACH resources for the at least one characteristic; and performing random access with the second device on the target BWP according to a determination that the condition is met.

[0007] In a fourth aspect, a method is provided, the method including: sending, at a second device, configuration information to a first device indicating a set of Bandwidth Parts (BWPs) and a set of Random Access Channel (RACH) configurations for the set of BWPs, and performing random access with the first device over a target BWP, where the random access procedure is triggered based on at least one characteristic, and the target BWP is configured with RACH resources for the at least one characteristic.

[0008] In a fifth aspect, an apparatus is provided, thus including: means for receiving, at a first device, configuration information from a second device indicating a set of Bandwidth Parts (BWPs) and a set of Random Access Channel (RACH) configurations of the set of BWPs; means for determining, at the first device, that a random access procedure is triggered based on at least one characteristic; means for determining, based on the set of RACH configurations, whether a condition for switching to a target BWP is met, the target BWP being configured with RACH resources for the at least one characteristic; and means for performing random access with the second device on the target BWP according to a determination that the condition is met.

[0009] In a sixth aspect, an apparatus is provided, thus including means for transmitting configuration information in a second device to a first device, the configuration information indicating a set of Bandwidth Parts (BWPs) and a set of Random Access Channel (RACH) configurations for the set of BWPs, and means for performing random access with the first device over a target BWP, where the random access procedure is triggered based on at least one characteristic, and the target BWP is configured with RACH resources for the at least one characteristic.

[0010] In a seventh aspect, there is provided a computer readable medium comprising program instructions for causing an apparatus to perform at least a method according to any one of the third and fourth aspects above.

[0011] It should be understood that the summary section is not intended to identify key or essential features of the embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become readily apparent through the following description.

[0012] Some example embodiments will now be described with reference to the accompanying drawings. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure may be implemented. [Diagram 2] FIG. 1 illustrates a signaling flow for selecting appropriate resources for a random access procedure, according to certain example embodiments of the present disclosure. [Diagram 3] 1 is a schematic diagram of a BWP, according to some example embodiments of the present disclosure. [Figure 4] FIG. 2 illustrates a flowchart of a method implemented in a first device, according to some example embodiments of the present disclosure. [Diagram 5] FIG. 2 illustrates a flowchart of a method implemented in a first device, according to some example embodiments of the present disclosure. [Figure 6] FIG. 1 is a simplified block diagram of an apparatus suitable for practicing example embodiments of the present disclosure. [Figure 7] 1 is a block diagram of an example computer-readable medium according to some example embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Throughout the drawings, the same or similar reference numbers represent the same or similar elements.

[0015] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are merely described for illustrative purposes, to assist those skilled in the art in understanding and practicing the present disclosure, but do not imply any limitations on the scope of the present disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0016] In the following description and claims, unless defined otherwise, 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 belongs.

[0017] References in this disclosure to "one embodiment," "embodiment," "example embodiment," and the like indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment need include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is believed to be within the knowledge of one of ordinary skill in the art to affect such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described.

[0018] Although the terms "first" and "second" may be used herein to describe various elements, it should be understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element can be referred to as a second element, and similarly, a second element can be referred to as a first element, without departing from the scope of the example embodiments. As used herein, the term "and / or" includes all combinations of one or more of the listed terms.

[0019] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, it will be understood that the terms "comprises," "comprising," "having," "having," "includes," and / or "including," as used herein, specify the presence of stated features, elements, and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0020] As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) Hardware-only circuit implementations (e.g., implementations using only analog and / or digital circuitry); and (b) A combination of hardware circuitry and software, such as (where applicable), (i) A combination of analog and / or digital hardware circuitry(s) and software / firmware; and (ii) any portion of hardware processor(s) (including digital signal processor(s)) with software, software, and memory(s) that work together to cause a device, such as a mobile phone or server, to perform various functions; and (c) Hardware circuitry(s) and / or processor(s) (e.g., microprocessor(s) or portion of microprocessor(s)) that require software (e.g., firmware) for operation, although the software may not be present when not necessary for operation.

[0021] This definition of circuitry applies to all uses of the term in this application, including any claims. As a further example, the term circuitry, as used in this application, also encompasses merely a hardware circuit or processor (or processors), or a portion of a hardware circuit or processor, and its (or their) accompanying software and / or firmware implementations. The term circuitry also encompasses, for example, baseband or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices, if applicable to certain claim elements.

[0022] As used herein, the term "communication network" refers to a network conforming to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE 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 the communication network may be performed according to any suitable generation of communication protocols, such as, without limitation, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocols, and / or any other protocols now known or later developed. The embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communication, it is to be understood that there are also future communication technologies and systems in which the present disclosure may be embodied. The scope of the present disclosure should not be considered as being limited to only the aforementioned systems.

[0023] As used herein, the term "network device" refers to a node in a communication network through which a terminal device accesses and receives services from the network. Depending on the terminology and technology applied, a network device may refer to the following: a base station (BS) or access point (AP), such as a Node B (NodeB or NB), evolved Node B (eNodeB or eNB), NR NB (also called gNB), remote radio unit (RRU), radio header (RH), remote radio head (RRH), relay, integrated access backhaul (IAB) node, low power node, such as femto, pico, non-terrestrial network (NTN) or non-terrestrial network device, such as satellite network device, low earth orbit (LEO) satellite and geosynchronous orbit (GEO) satellite, airborne network device, etc. In some example embodiments, a gNB can be divided into a centralized unit (CU) and a distributed unit (DU). The CU hosts the upper layers of the protocol stack, including Radio Resource Control (RRC) and Packet Data Convergence Protocol (PDCP), while the DU hosts the lower layers, such as the physical layer, the Media Access Control (MAC) layer, and the Radio Link Control (RLC) layer.

[0024] The term "terminal device" refers to any end device that may be capable of wireless communication. By way of example and not limitation, a terminal device may be a communication device, a user equipment (UE), a subscriber station (SS), a mobile subscriber station, a mobile station (MS), or an 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 playback appliances, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded equipment (LEE), laptop mounted equipment (LME), USB dongles, smart devices, wireless customer premises equipment (CPE), Internet of Things (IoT) devices, watches or other wearables, head mounted displays (HMD), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain situations), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment", and "UE" may be used interchangeably.

[0025] As mentioned above, the terminal device may initiate a random access procedure to access the PRACH. The random access procedure (RACH) may be contention-based (CBRA) or contention-free (CFRA). A technique called "RACH partition" has been proposed. The RACH partition strategy may be optimized to enhance the access performance of the network. For example, based on different types of services, the RACH partition strategy may partition the random access channel (RACH) resources to allocate to each type of service. The term "RACH resource" as used herein may refer to the time / frequency resource used for the RACH (i.e., the so-called RACH opportunity-RO) or the preamble of the RACH, and the division of the RACH may be achieved by dividing the PRACH resource (i.e., different RACH opportunities are mapped to different characteristics) or by dividing the preamble associated with the RACH opportunity (i.e., different preambles of the RO are mapped to different characteristics). Furthermore, the terminal device may be configured with one or more BWPs. An end device may be configured with up to four BWPs for the downlink and uplink, but at any given time, only one BWP is active for the downlink and only one for the uplink.

[0026] Since the configuration of many different RACH partitions is a burden for the network devices, they may be configured only on one particular BWP where most of the terminal devices have RACH partitions available, for example in the initial BWP. Thus, whenever a terminal device operates on a dedicated BWP that may not have a RACH partition available for the set of features that triggered the RA procedure, it will use the common RACH (if configured on the BWP), which may not provide optimal performance for the terminal device.

[0027] To solve at least some of the above and other potential problems, a new solution to selecting an appropriate BWP for a random access procedure is needed. According to an embodiment of the present disclosure, a terminal device receives configuration information from a network device. The configuration information indicates a set of BWPs and a RACH configuration for the set of BWPs. When a random access procedure is triggered for a certain combination of characteristics, the terminal device determines whether a condition for switching to a target BWP is met. If the condition is met, the terminal device switches to the target BWP. In this way, resource efficiency is improved.

[0028] 1 illustrates a schematic diagram of a communication environment 100 in which embodiments of the present disclosure may be implemented. The communication environment 100 is part of a communication network and includes device 110-1, device 110-2, ...., device 110-N, which may be collectively referred to as "first device(s) 110." The communication environment 100 further includes a second device 120 that may communicate with the first device(s) 110.

[0029] The communication environment 100 may include any suitable number of devices and cells. In the communication environment 100, the first device 110 and the second device 120 can communicate data and control information with each other. If the first device 110 is a terminal device and the second device 120 is a network device, the link from the second device 120 to the first device 110 is referred to as a downlink (DL), while the link from the first device 110 to the second device 120 is referred to as an uplink (UL). The second device 120 and the first device 110 are interchangeable.

[0030] It should be understood that the number of first devices and cells and their connections shown in Figure 1 are provided for illustrative purposes, without implying any limitation, and environment 100 may include any suitable number of devices and networks adapted to implement embodiments of the present disclosure.

[0031] Communications in the communication environment 100 may be performed according to any suitable communications protocol(s), such as, without limitation, cellular communications protocols, such as first generation (1G), second generation (2G), third generation (3G), fourth generation (4G), and fifth generation (5G), wireless local network communications protocols, such as Institute for Electrical and Electronics Engineers (IEEE) 802.11, and / or any other protocols now known or later developed. Furthermore, communications may utilize any suitable wireless communication technology, such as, without limitation, 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 multiplexing (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), and / or any other technology now known or later developed.

[0032] Exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. Referring now to Figure 2, a signaling flow 200 for selecting resources for a random access procedure is illustrated, according to an exemplary embodiment of the present disclosure. For illustrative purposes, the signaling flow 200 is described with reference to Figure 1. The signaling flow 200 may include a first device 110-1 and a second device 120.

[0033] The second device 120 transmits 2010 configuration information to the first device 110-1. The configuration information indicates a set of BWPs and a set of RACH configurations for the set of BWPs. In some example embodiments, the configuration information may be transmitted via RRC signaling. Alternatively, the configuration information may be transmitted via media access control (MAC) signaling. In other embodiments, the configuration information may be transmitted via physical layer (PHY) signaling.

[0034] In some example embodiments, the configuration information may include an index of the BWP and the corresponding RACH configuration of each BWP. Each BWP defined for a numerology may have three different parameters: subcarrier spacing, symbol time, and cyclic prefix length. The RACH configuration may include one or more of the following: BWP bandwidth size, frequency location, and control resource set (CORESET). Each DL BWP may include at least one CORESET with a UE-specific search space (USS), while in the primary carrier, at least one of the configured DL BWPs includes one CORESET with a common search space (CSS). For the uplink, the terminal device must not transmit PUSCH or PUCCH outside the active bandwidth portion. There is an initial active BWP for the terminal device during initial access until the terminal device is explicitly configured by a BWP during or after the establishment of the RRC connection. As used herein, the term "initial BWP" may refer to a BWP used to perform an initial access process. As used herein, the term "active BWP" may refer to a UE-specific / dedicated BWP that cannot be used to perform an access process. An active BWP is a BWP that a terminal device uses for data transfer when an RRC connection is established. As used herein, the term "default BWP" may refer to a UE-specific BWP that is configured during RRC reconfiguration. If a default BWP is not configured, an initial BWP may be referred to as the default BWP. For example, as shown in FIG. 3, the configuration information may include RACH configurations for BWP 310, BWP 320, BWP 330, and BWP 340. By way of example only, BWP 310 may be the initial BWP, BWP 320 may be the active BWP, and BWP 340 may be the default BWP. It should be noted that FIG. 3 is merely an example and not a limitation.

[0035] In other embodiments, the configuration information may include a set of features that trigger a random access procedure. As used herein, the term "feature" may refer to a cause that may trigger a random access procedure. In this case, the configuration information may indicate that one or more BWPs in the set of BWPs are configured with RACH resources for one or more features. Alternatively, the configuration information may indicate that one or more BWPs in the set of BWPs are not configured with RACH resources for one or more features. It should be noted that Table 1 is merely an example and other combinations of features and priorities may be possible. [Table 1]

[0036] The first device 110-1 determines that the random access procedure is triggered based on the at least one feature 2020. For example, the at least one feature may include one or more of RedCap, SDT, CovEnh, or slice. It should be noted that the multiple features may include other features.

[0037] The first device 110-1 determines whether a condition for switching to the target BWP is met 2030. In some example embodiments, the condition may be included in the configuration information received from the second device 120. Alternatively, the condition may be predefined in the first device 110-1. If the condition is met, the first device 110-1 switches to the target BWP 2040. In this way, when a random access is triggered in the RRC connected mode, the first device 110-1 may consider not only the RACH configuration of the active BWP but also the RACH configuration of the set of BWPs, thereby improving resource efficiency and distributing the RACH load. It should be noted that the embodiments of the present disclosure may also be applicable to RRC idle and RRC inactive states.

[0038] In some example embodiments, the first device 110-1 may first determine whether the active BWP is configured with a RACH resource for at least one feature. If the active BWP is not configured with a RACH resource for at least one feature, the first device 110-1 may switch to an initial BWP. In this case, the first device 110-1 may further determine whether the initial BWP is configured with a RACH resource for at least one feature. For example, with reference to FIG. 3, if the BWP 320 is not configured with a RACH resource for at least one feature, the first device 110-1 may switch to the BWP 310. If the initial BWP is configured with a RACH resource for at least one feature, the initial BWP may be considered to be the target BWP. If the initial BWP is not configured with a RACH resource for at least one feature, the first device 110-1 may determine whether other BWPs in the set of BWPs (e.g., BWP 330 and BWP 340) are configured with a RACH resource for at least one feature. If another BWP is configured with RACH resources for at least one feature, the initial BWP can be considered as the target BWP. In this way, there is less impact on the current mechanism and it is easy to implement. In some examples, when the random access procedure is triggered based on multiple features, the first device 110-1 may determine a priority order for the multiple features and determine the at least one feature as the feature with the highest priority.

[0039] Alternatively, the first device 110-1 may first determine whether any BWP in the set of BWPs is configured with a RACH resource for at least one feature. In this case, if a BWP is configured with a RACH resource for at least one feature, such a BWP may be considered to be a target BWP. In another embodiment, if none of the BWPs in the set of BWPs is configured with a RACH resource for at least one feature, the first device 110-1 may perform random access on the active BWP. Alternatively, if none of the BWPs in the set of BWPs is configured with a RACH resource for at least one feature, the first device 110-1 may switch to an initial BWP. In this case, the first device 110-1 may perform random access on the initial BWP. In this way, an appropriate BWP can be quickly selected.

[0040] In some example embodiments, when a random access for coverage extension is triggered, the first device 110-1 may determine whether the active BWP is configured with RACH resources for coverage extension based on a set of RACH configurations. In this case, if the active BWP is not configured with RACH resources for coverage extension and a condition in the configuration information may indicate a first reference signal received power (RSRP) threshold for coverage extension, the first device 110-1 may compare a value of RSRP on the active BWP with a first RSRP threshold. The first device 110-1 may determine whether a value of RSRP on the active BWP is below the first RSRP threshold based on the comparison. If the value of RSRP is below the first RSRP threshold, the first device 110-1 may switch to a target BWP configured with RACH resources for coverage extension. For example, if the RSRP value of the BWP 320 falls below the first RSRP threshold and the configuration information indicates that the BWP 330 is configured with RACH resources for coverage extension, the first device 110-1 may switch to the BWP 330. In this manner, the BWP for random access may be appropriately selected.

[0041] In another embodiment, when the random access for reduced capability is triggered, the first device 110-1 may determine whether the active BWP is configured with RACH resources for reduced capability based on the set of RACH configurations. In this case, if the active BWP is not configured with RACH resources for reduced capability and the condition in the configuration information may indicate a second RSRP threshold for reduced capability, the first device 110-1 may compare the value of RSRP on the active BWP with the second RSRP threshold. The first device 110-1 may determine whether the value of RSRP on the active BWP is below the second RSRP threshold based on the comparison. If the value of RSRP is below the second RSRP threshold, the first device 110-1 may switch to a target BWP configured with RACH resources for reduced capability. For example, if the RSRP value of the BWP 320 falls below the second RSRP threshold and the configuration information indicates that the BWP 340 is configured with RACH resources for reduced capability, the first device 110-1 can switch to the BWP 340. The second RSRP threshold can be different for 1RX (receiver / receiver chain / receiver branch) and 2RX terminal devices. In one example, the second RSRP threshold can also be applied by an IDLE / INACTIVE RedCap terminal device to determine whether to access via a RedCap-specific initial BWP or via a cell's initial BWP (if the RedCap UE can also support the BW of the cell's initial BWP). In this way, the BWP for random access can be appropriately selected.

[0042] Alternatively, when a random access for reduced capability is triggered, the first device 110-1 may determine whether the active BWP is configured with RACH resources for reduced capability based on a set of RACH configurations. If the active BWP is not configured with RACH resources for reduced capability, the first device 110-1 may switch to a target BWP configured with RACH resources for reduced capability. In an example embodiment, if the first device 110-1 supports only one RX (receiver / receiver chain), the first device 110-1 may always switch to a BWP that supports a RACH partition specific to the reduced capability whenever such a BWP is available. In this way, a BWP for random access can be appropriately selected.

[0043] In some example embodiments, when a random access for a slice / slice group is triggered, the first device 110-1 may determine whether an active BWP is configured with RACH resources for the slice / slice group based on a set of RACH configurations. If the active BWP is not configured with RACH resources for the slice / slice group, the first device 110-1 may switch to a target BWP configured with RACH resources for the slice. For example, if the BWP 320 is not configured with RACH resources for the slice / slice group and the configuration information indicates that the BWP 330 is configured with RACH resources for the slice / slice group, the first device 110-1 may switch to the BWP 330. In this way, a BWP for random access can be appropriately selected and the RACH load can be distributed.

[0044] In an example embodiment, the second device 120 may explicitly configure the first device 110-1 to perform random access over an active BWP if there is a RACH resource configured for the active BWP. In other words, BWP switching for random access may be disabled. For example, the second device 120 may send downlink control information or an RRC configuration including a disable indication for BWP switching to the first device 110-1.

[0045] Referring again to FIG. 2, the first device 110-1 performs random access with the second device 120 on the target BWP 2050. In some embodiments, after the random access is triggered, the first device 110-1 may perform the random access on the active BWP configured with the common RACH resource. If the number of random access failures exceeds a number threshold, the first device 110-1 may determine that the conditions for switching to the target BWP are met. In this case, the first device 110-1 may switch to the target BWP configured with the RACH resource for at least one characteristic. The number threshold may be configured by the second device 120 via any suitable signaling. Alternatively, the number threshold may be predefined in the first device 110-1.

[0046] According to the above embodiment, for example, when the network device predicts that 1RX RedCap UEs will not survive on a common RACH (e.g., due to RAR coverage issues), the feature-specific RACH partitioning can also be applied in CONNECTED mode. Furthermore, BWP switching based on feature-specific RA partitioning is enabled, improving resource efficiency, because the NW does not need to replicate RA partitioning for dedicated BWPs to benefit. Furthermore, RACH load balancing can be achieved by distributing feature-specific RACH partitions to different BWPs.

[0047] FIG. 4 illustrates a flowchart of an example method 400 implemented in the first device 110-1, according to some example embodiments of the present disclosure.

[0048] At block 410, the first device 110-1 receives configuration information from the second device 120. The configuration information indicates a set of BWPs and a set of RACH configurations for the set of BWPs. In some example embodiments, the configuration information may be transmitted via RRC signaling. Alternatively, the configuration information may be transmitted via MAC signaling. In other embodiments, the configuration information may be transmitted via PHY signaling.

[0049] In some example embodiments, the configuration information may include an index of the BWP and the corresponding RACH configuration of each BWP. Each BWP defined for a numerology may have three different parameters: subcarrier spacing, symbol time, and cyclic prefix length. The RACH configuration may include one or more of the following: BWP bandwidth size, frequency location, and control resource set (CORESET). Each DL BWP may include at least one CORESET with a UE-specific search space (USS), but in the primary carrier, at least one of the configured DL BWPs includes one CORESET with a common search space (CSS). For the uplink, the terminal device must not transmit PUSCH or PUCCH outside the active bandwidth portion. There is an initial active BWP for the terminal device during initial access until the terminal device is explicitly configured by a BWP during or after the establishment of the RRC connection.

[0050] In other embodiments, the configuration information may include a set of features that trigger a random access procedure. As used herein, the term "feature" may refer to a cause that may trigger a random access procedure. In this case, the configuration information may indicate that one or more BWPs in the set of BWPs are configured with RACH resources for one or more features. Alternatively, the configuration information may indicate that one or more BWPs in the set of BWPs are not configured with RACH resources for one or more features.

[0051] In block 420, the first device 110-1 determines that the random access procedure is triggered based on at least one feature. For example, the at least one feature may include one or more of RedCap, SDT, CovEnh, or slice. It should be noted that the multiple features may include other features.

[0052] In block 430, the first device 110-1 determines whether conditions for switching to the target BWP are met. In some example embodiments, the conditions may be included in the configuration information received from the second device 120. Alternatively, the conditions may be predefined in the first device 110-1.

[0053] In block 440, if the condition is met, the first device 110-1 performs random access with the second device 120 on the target BWP. In this way, when random access is triggered in RRC connected mode, the first device 110-1 may consider not only the RACH configuration of the active BWP but also the RACH configuration of the set of BWPs, thereby improving resource efficiency and distributing the RACH load.

[0054] In some example embodiments, the first device 110-1 may first determine whether the active BWP is configured with a RACH resource for at least one feature. If the active BWP is not configured with a RACH resource for at least one feature, the first device 110-1 may switch to an initial BWP. In this case, the first device 110-1 may further determine whether the initial BWP is configured with a RACH resource for at least one feature. If the initial BWP is configured with a RACH resource for at least one feature, the initial BWP may be considered to be a target BWP. If the initial BWP is not configured with a RACH resource for at least one feature, the first device 110-1 may determine whether other BWPs in the set of BWPs are configured with a RACH resource for at least one feature. If the other BWP is configured with a RACH resource for at least one feature, the initial BWP may be considered to be a target BWP. In this way, there is less impact on the current mechanism and it is easy to implement. In some examples, when the random access procedure is triggered based on multiple features, the first device 110-1 may determine a priority order for the multiple features and determine the at least one feature to be the highest priority.

[0055] Alternatively, the first device 110-1 may first determine whether any BWP in the set of BWPs is configured with a RACH resource for at least one feature. In this case, if a BWP is configured with a RACH resource for at least one feature, such a BWP may be considered to be a target BWP. In another embodiment, if none of the BWPs in the set of BWPs is configured with a RACH resource for at least one feature, the first device 110-1 may perform random access on the active BWP. Alternatively, if none of the BWPs in the set of BWPs is configured with a RACH resource for at least one feature, the first device 110-1 may switch to an initial BWP. In this case, the first device 110-1 may perform random access on the initial BWP. In this way, an appropriate BWP can be quickly selected.

[0056] In some example embodiments, when a random access for coverage extension is triggered, the first device 110-1 may determine whether the active BWP is configured with RACH resources for coverage extension based on a set of RACH configurations. In this case, if the active BWP is not configured with RACH resources for coverage extension and a condition in the configuration information may indicate a first reference signal received power (RSRP) threshold for coverage extension, the first device 110-1 may compare a value of RSRP on the active BWP with a first RSRP threshold. The first device 110-1 may determine whether a value of RSRP on the active BWP is below the first RSRP threshold based on the comparison. If the value of RSRP is below the first RSRP threshold, the first device 110-1 may switch to a target BWP configured with RACH resources for coverage extension. In this way, a BWP for random access can be appropriately selected.

[0057] In another embodiment, when the random access for reduced capability is triggered, the first device 110-1 may determine whether the active BWP is configured with RACH resources for reduced capability based on the set of RACH configurations. In this case, if the active BWP is not configured with RACH resources for reduced capability and the condition in the configuration information may indicate a second RSRP threshold for reduced capability, the first device 110-1 may compare the value of RSRP on the active BWP with the second RSRP threshold. The first device 110-1 may determine whether the value of RSRP on the active BWP is below the second RSRP threshold based on the comparison. If the value of RSRP is below the second RSRP threshold, the first device 110-1 may switch to a target BWP configured with RACH resources for reduced capability. The second RSRP threshold may be different for a 1RX terminal device and a 2RX terminal device. In one example, the second RSRP threshold may also be applied by an IDLE / INACTIVE RedCap terminal device to determine whether to access via a RedCap specific initial BWP or via a cell's initial BWP (if the RedCap UE can also support the BW of the cell's initial BWP). In this way, a BWP for random access may be appropriately selected.

[0058] Alternatively, when a random access for reduced capability is triggered, the first device 110-1 may determine whether the active BWP is configured with RACH resources for reduced capability based on a set of RACH configurations. If the active BWP is not configured with RACH resources for reduced capability, the first device 110-1 may switch to a target BWP configured with RACH resources for reduced capability. In an example embodiment, if the first device 110-1 supports only one RX (receiver / receiver chain), the first device 110-1 may always switch to a BWP that supports a RACH partition specific to the reduced capability whenever such a BWP is available. In this way, a BWP for random access can be appropriately selected.

[0059] In some example embodiments, when a random access for a slice / slice group is triggered, the first device 110-1 may determine whether an active BWP is configured with RACH resources for the slice / slice group based on a set of RACH configurations. If the active BWP is not configured with RACH resources for the slice / slice group, the first device 110-1 may switch to a target BWP configured with RACH resources for the slice. In this way, a BWP for random access can be appropriately selected and the RACH load can be distributed.

[0060] In an example embodiment, the second device 120 may explicitly configure the first device 110-1 to perform random access over an active BWP if there is a RACH resource configured for the active BWP. In other words, BWP switching for random access may be disabled. For example, the second device 120 may send downlink control information or an RRC configuration to the first device 110-1 that includes a disable indication for BWP switching.

[0061] In some embodiments, after the random access is triggered, the first device 110-1 may perform the random access on an active BWP configured with a common RACH resource. If the number of random access failures exceeds a number threshold, the first device 110-1 may determine that a condition for switching to a target BWP is met. In this case, the first device 110-1 may switch to a target BWP configured with a RACH resource for at least one characteristic. The number threshold may be configured by the second device 120 via any suitable signaling. Alternatively, the number threshold may be predefined in the first device 110-1.

[0062] FIG. 5 illustrates a flowchart of an example method 500 implemented in the second device 120, according to some example embodiments of the present disclosure.

[0063] At block 510, the second device 120 transmits configuration information to the first device 110-1. The configuration information indicates a set of BWPs and a set of RACH configurations for the set of BWPs. In some example embodiments, the configuration information may be transmitted via RRC signaling. Alternatively, the configuration information may be transmitted via MAC signaling. In other embodiments, the configuration information may be transmitted via PHY signaling.

[0064] In some example embodiments, the configuration information may include an index of the BWP and the corresponding RACH configuration of each BWP. Each BWP defined for a numerology may have three different parameters: subcarrier spacing, symbol time, and cyclic prefix length. The RACH configuration may include one or more of the BWP bandwidth size, frequency location, and control resource set (CORESET). Each DL BWP may include at least one CORESET with a UE-specific search space (USS), but in the primary carrier, at least one of the configured DL BWPs includes one CORESET with a common search space (CSS). For the uplink, the terminal device must not transmit PUSCH or PUCCH outside the active bandwidth portion. There is an initial active BWP for the terminal device during initial access until the terminal device is explicitly configured by a BWP during or after the establishment of the RRC connection.

[0065] In other embodiments, the configuration information may include a set of features that trigger a random access procedure. As used herein, the term "feature" may refer to a cause that may trigger a random access procedure. In this case, the configuration information may indicate that one or more BWPs in the set of BWPs are configured with RACH resources for one or more features. Alternatively, the configuration information may indicate that one or more BWPs in the set of BWPs are not configured with RACH resources for one or more features.

[0066] At block 520, the second device 120 performs random access with the first device 110-1 over a target BWP configured with RACH resources for the at least one feature.

[0067] In some example embodiments, a first apparatus (e.g., first device 110) capable of performing any of the methods 400 may include means for performing each operation of the method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuit or a software module. The first apparatus may be implemented as or included in the first device 110. In some example embodiments, the means may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to cause execution of the apparatus using the at least one processor.

[0068] In some embodiments, the first apparatus includes means for receiving, at the first device, configuration information from the second device indicating a set of bandwidth portions (BWPs) and a set of random access channel (RACH) configurations for the set of BWPs; means for determining, at the first device, that a random access procedure has been triggered based on at least one characteristic; means for determining whether a condition for switching to a target BWP is met based on the set of RACH configurations, the target BWP being configured with RACH resources for the at least one characteristic; and means for performing random access with the second device on the target BWP according to a determination that the condition is met.

[0069] In some embodiments, the set of RACH configurations further includes conditions for switching to the target BWP.

[0070] In some embodiments, the at least one feature includes one of: reduced capacity, small data transmission, coverage extension, or slicing.

[0071] In some embodiments, the condition indicates a first reference signal received power (RSRP) threshold for coverage extension, and the first apparatus further includes means for determining whether an active BWP of the first device is configured with RACH resources for coverage extension based on the set of RACH configurations, and means for determining a value of RSRP on the active BWP according to a determination that the active BWP is not configured with RACH resources for coverage extension, and the means for determining whether a condition for switching to a target BWP is met includes means for comparing a value of RSRP of the active BWP with a first RSRP threshold, means for determining that a condition for switching to the target BWP is met according to a determination that the value of RSRP is below the first RSRP threshold, and means for switching from the active BWP to the target BWP configured with RACH resources for coverage extension.

[0072] In some embodiments, the condition indicates a second RSRP threshold associated with the reduced capacity, and the first device further includes means for determining a value of the RSRP on the active BWP, and the means for determining whether the condition for switching to the target BWP is met includes means for comparing the value of the RSRP of the active BWP with the second RSRP threshold, means for determining that the condition for switching to the target BWP is met according to a determination that the value of the RSRP is below the second RSRP threshold, and means for switching from the active BWP to the target BWP configured with RACH resources for the reduced capacity.

[0073] In some embodiments, the means for determining whether conditions for switching to a target BWP are met includes means for determining whether the active BWP is configured with RACH resources for reduced capacity, and means for switching from the active BWP to a target BWP configured with RACH resources for reduced capacity according to a determination that the active BWP is not configured with RACH resources for reduced capacity.

[0074] In some embodiments, the means for determining whether conditions for switching to a target BWP are met includes means for determining whether an active BWP is configured with RACH resources for the slice, and means for switching from the active BWP to a target BWP that is configured with RACH resources for the slice according to a determination that the active BWP is not configured with RACH resources for the slice.

[0075] In some embodiments, the first apparatus includes means for determining whether an active BWP of the first device is configured with a RACH configuration based on a set of RACH configurations, and means for switching to an initial BWP according to a determination that the active BWP is not configured with a RACH configuration, wherein the means for determining whether conditions for switching to a target BWP are met includes means for determining whether conditions for switching to the target BWP are met according to a determination that the initial BWP does not support at least one feature.

[0076] In some embodiments, the means for determining whether conditions for switching to the target BWP are met includes means for performing random access on an active BWP configured with common RACH resources and means for determining that conditions for switching to the target BWP are met according to a determination that the number of random access failures on the active BWP exceeds a number threshold.

[0077] In some embodiments, the means for receiving the configuration information includes means for receiving the configuration information via one of Radio Resource Control (RRC) signaling, Media Access Control (MAC) signaling, or Physical (PHY) signaling.

[0078] In some embodiments, the first device is a terminal device and the second device is a network device.

[0079] In some example embodiments, a second apparatus (e.g., second device 120) capable of performing any of the methods 500 may include means for performing each operation of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuit or a software module. The first apparatus may be implemented as or included in the second device 120. In some example embodiments, the means may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to cause execution of the apparatus using the at least one processor.

[0080] In some embodiments, the second apparatus includes means, at the second device, for transmitting configuration information to the first device indicating a set of bandwidth portions (BWPs) and a set of random access channel (RACH) configurations for the set of BWPs, and means for performing random access with the first device on a target BWP, where the random access procedure is triggered based on at least one characteristic, and the target BWP is configured with RACH resources for the at least one characteristic.

[0081] In some embodiments, the set of RACH configurations further includes conditions for switching to the target BWP.

[0082] In some embodiments, the at least one feature includes one of: reduced capacity, small data transmission, coverage extension, or slicing.

[0083] In some embodiments, the condition indicates a first reference signal received power (RSRP) threshold for coverage extension.

[0084] In some embodiments, the condition indicates a second RSRP threshold associated with reduced performance.

[0085] In some embodiments, the means for transmitting the configuration information includes means for transmitting the configuration information via one of Radio Resource Control (RRC) signaling, Media Access Control (MAC) signaling, or Physical (PHY) signaling.

[0086] In some embodiments, the first device is a terminal device and the second device is a network device.

[0087] 6 is a simplified block diagram of a device 600 suitable for implementing example embodiments of the present disclosure. The device 600 may be provided to implement a communications device, such as the first device 110 as shown in FIG 1. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communications modules 640 coupled to the processor 610.

[0088] The communication module 640 is for bidirectional communication. The communication module 640 has one or more communication interfaces that facilitate communication with one or more other modules or devices. The communication interface may represent any interface necessary for communication with other network elements. In some example embodiments, the communication module 640 may include at least one antenna.

[0089] The processor 610 may be of any type suitable for a local technology network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures, as non-limiting examples. The device 600 may have multiple processors, such as application specific integrated circuit chips slaved in time to a clock that synchronizes the main processor.

[0090] The memory 620 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) 624, electrically programmable read only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), optical disks, laser disks, and other magnetic and / or optical storage devices. Examples of volatile memories include, but are not limited to, random access memory (RAM) 622 and other volatile memories that do not persist while power is off.

[0091] The computer program 630 includes computer executable instructions that are executed by the associated processor 610. The program 630 may be stored in a memory, for example in the ROM 624. The processor 610 may load the program 630 into the RAM 622 to perform any suitable operations and processes.

[0092] Some exemplary embodiments of the present disclosure may be implemented by a program 630 such that the device 600 may execute any process of the present disclosure, such as those described with reference to Figures 2 to 5. Also, the exemplary embodiments of the present disclosure may be implemented by hardware or a combination of software and hardware.

[0093] In some example embodiments, the program 630 may be tangibly contained in a computer readable medium that may be included in the device 600 (such as in the memory 620) or in other storage devices accessible by the device 600. The device 600 may load the program 630 from the computer readable medium into the RAM 622 for execution. The computer readable medium may include any type of tangible non-volatile storage, for example, ROM, EPROM, flash memory, hard disk, CD, DVD, and other magnetic and / or optical storage. FIG. 7 shows an example of a computer readable medium 700 in the form of an optical storage disk. The computer readable medium has the program 630 stored thereon.

[0094] In general, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that the blocks, apparatus, systems, techniques, or methods described herein may be implemented in, by way of non-limiting examples, hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controller, or other computing device, or some combination thereof.

[0095] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, that execute in a device on a target physical or virtual processor to perform any of the methods described above with reference to Figures 2-5. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split among program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed in local or distributed devices. In a distributed device, program modules may be located in both local and remote storage media.

[0096] The program codes for carrying out the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, a special purpose computer, or other programmable data processing apparatus, and when executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are performed. The program codes may be executed entirely on the machine, partially on the machine as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0097] In the context of the present disclosure, computer program code or associated 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.

[0098] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the above. More specific examples of the computer-readable storage medium include an electrical connection with one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0099] Furthermore, although operations are shown in a particular order, this should not be understood as requiring such operations to be performed in the particular order or sequence shown, or to perform all of the illustrated operations, in order to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although details of certain specific implementations are included in the foregoing description, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to certain embodiments. Certain features described in the context of separate embodiments may be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may be implemented in multiple embodiments separately or in any suitable subcombination.

[0100] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it is to be understood that the present disclosure as defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A first device, At least one processor; at least one memory containing computer program code; The at least one memory and the computer program code are adapted to cause the first device, using the at least one processor, to: receiving configuration information from a second device indicating a set of bandwidth portions (BWPs) and a set of random access channel (RACH) configurations for the set of BWPs; determining, at the first device, that a random access procedure has been triggered based on at least one characteristic; determining whether a condition for switching to a target BWP is met based on the set of RACH configurations, the target BWP being configured with RACH resources for the at least one characteristic; and performing the random access with the second device on the target BWP according to a determination that the condition is satisfied.

2. The first device of claim 1 , wherein the set of RACH configurations further includes the condition for switching to the target BWP.

3. The at least one feature is decreased ability, Small data transmission, Coverage extension, or The first device of claim 1 including one of the slices.

4. The condition indicates a first reference signal received power (RSRP) threshold for coverage extension; The at least one memory and the computer program code further cause the first device, using the at least one processor, to: determining whether an active BWP of the first device is configured with RACH resources for coverage extension based on the set of RACH configurations; determining a value of an RSRP on the active BWP according to a determination that the active BWP is not configured with RACH resources for the coverage extension; The at least one memory and the computer program code, using the at least one processor, may further include: causing the first device to: determine whether the condition for switching to the target BWP is met; comparing the value of the RSRP of the active BWP to a first RSRP threshold; determining that the condition for switching to the target BWP is satisfied according to a determination that the value of the RSRP is below the first RSRP threshold; and switching from the active BWP to the target BWP configured with RACH resources for the coverage extension.

5. the condition indicating a second RSRP threshold associated with reduced performance; The at least one memory and the computer program code further cause the first device, using the at least one processor, to: determining a value of RSRP on the active BWP; The at least one memory and the computer program code, using the at least one processor, further cause the first device to: determine whether the condition for switching to the target BWP is satisfied; comparing the value of the RSRP of the active BWP to a second RSRP threshold; determining that the condition for switching to the target BWP is satisfied in accordance with a determination that the value of the RSRP is below the second RSRP threshold; and switching from the active BWP to the target BWP configured with RACH resources for the capacity reduction.

6. The at least one memory and the computer program code, using the at least one processor, further cause the first device to: determine whether the condition for switching to the target BWP is satisfied; determining whether an active BWP is configured with RACH resources for the reduced capacity; and switching from the active BWP to the target BWP configured with a RACH resource for the capacity degradation according to a determination that the active BWP is not configured with a RACH resource for the capacity degradation.

7. The at least one memory and the computer program code, using the at least one processor, further cause the first device to: determine whether the condition for switching to the target BWP is satisfied; Determining whether an active BWP is configured with RACH resources for a slice; and switching from the active BWP to the target BWP that is configured with the RACH resources for the slice according to a determination that the active BWP is not configured with the RACH resources for the slice.

8. The at least one memory and the computer program code further cause the first device, using the at least one processor, to: determining whether an active BWP of the first device is configured with a RACH configuration based on the set of RACH configurations; and switching to an initial BWP in accordance with a determination that the active BWP is not configured with the RACH configuration; The at least one memory and the computer program code, using the at least one processor, further cause the first device to: determine whether the condition for switching to the target BWP is satisfied; and determining whether the condition for switching to the target BWP is satisfied according to a determination that the initial BWP does not support the at least one feature.

9. The at least one memory and the computer program code, using the at least one processor, further cause the first device to: determine whether the condition for switching to the target BWP is satisfied; performing random access on an active BWP configured with common RACH resources; and determining that the condition for switching to the target BWP is satisfied according to a determination that a number of random access failures on the active BWP exceeds a number threshold.

10. The at least one memory and the computer program code, using the at least one processor, further cause the first device to: The configuration information is Radio Resource Control (RRC) signaling; Media Access Control (MAC) signaling, or The first device according to any one of claims 1 to 9, configured to cause by receiving via one of the Physical (PHY) signalling.

11. The first device according to any one of claims 1 to 10, wherein the first device is a terminal device and the second device is a network device.

12. a second device, At least one processor; at least one memory containing computer program code; The at least one memory and the computer program code are adapted to cause the second device, using the at least one processor, to: transmitting configuration information to a first device indicating a set of bandwidth portions (BWPs) and a set of random access channel (RACH) configurations for the set of BWPs; and performing a random access with the first device on a target BWP, the random access procedure being triggered based on at least one feature, the target BWP being configured with RACH resources for the at least one feature.

13. The second device of claim 12 , wherein the set of RACH configurations further includes a condition for switching to the target BWP.

14. The at least one feature is decreased ability, Small data transmission, Coverage extension, or The second device of claim 12 comprising one of the slices.

15. The second device of any of claims 12 to 14, wherein the condition indicates a first reference signal received power (RSRP) threshold for coverage extension.

16. The second device of any of claims 12 to 14, wherein the condition indicates a second RSRP threshold associated with reduced performance.

17. The at least one memory and the computer program code further configure the first device to: The configuration information is Radio Resource Control (RRC) signaling; Media Access Control (MAC) signaling, or The second device according to any one of claims 12 to 16, configured to cause by transmitting via one of the physical (PHY) signaling.

18. The second device according to any one of claims 12 to 17, wherein the first device is a terminal device and the second device is a network device.

19. 1. A method comprising: receiving, at a first device, configuration information from a second device indicating a set of bandwidth portions (BWPs) and a set of random access channel (RACH) configurations for the set of BWPs; determining, at the first device, that a random access procedure has been triggered based on at least one characteristic; determining whether a condition for switching to a target BWP is met based on the set of RACH configurations, the target BWP being configured with RACH resources for the at least one characteristic; and performing the random access with the second device on the target BWP in accordance with a determination that the condition is satisfied.

20. 20. The method of claim 19, wherein the set of RACH configurations further comprises the condition for switching to the target BWP.

21. The at least one feature is decreased ability, Small data transmission, Coverage extension, or The method of claim 19 , further comprising one of the slices.

22. The condition indicates a first reference signal received power (RSRP) threshold for coverage extension, and the method further comprises: determining whether an active BWP of the first device is configured with RACH resources for coverage extension based on the set of RACH configurations; determining a value of an RSRP on the active BWP in accordance with a determination that the active BWP is not configured with RACH resources for the coverage extension; Determining whether the condition for switching to the target BWP is satisfied includes: comparing the value of the RSRP of the active BWP to a first RSRP threshold; determining that the condition for switching to the target BWP is satisfied according to a determination that the value of the RSRP is below the first RSRP threshold; and switching from the active BWP to the target BWP configured with RACH resources for the coverage extension.

23. The condition indicates a second RSRP threshold associated with reduced performance, and the method further comprises: determining a value of RSRP on an active BWP; Determining whether the condition for switching to the target BWP is satisfied includes: comparing the value of the RSRP of the active BWP to a second RSRP threshold; determining that the condition for switching to the target BWP is satisfied in accordance with a determination that the value of the RSRP is below the second RSRP threshold; and switching from the active BWP to the target BWP configured with RACH resources for the capacity reduction.

24. Determining whether the condition for switching to the target BWP is satisfied includes: determining whether an active BWP is configured with RACH resources for the reduced capacity; and switching from the active BWP to the target BWP that is configured with a RACH resource for the capacity degradation according to a determination that the active BWP is not configured with a RACH resource for the capacity degradation.

25. Determining whether the condition for switching to the target BWP is satisfied includes: Determining whether an active BWP is configured with RACH resources for a slice; A method according to any one of claims 19 to 21, comprising: switching from the active BWP to the target BWP that is configured with the RACH resources for the slice according to a determination that the active BWP is not configured with the RACH resources for the slice.

26. determining whether an active BWP of the first device is configured with a RACH configuration based on the set of RACH configurations; switching to an initial BWP in accordance with a determination that the active BWP is not configured with the RACH configuration; Determining whether the condition for switching to the target BWP is satisfied includes: The method of any one of claims 19 to 25, comprising: determining whether the condition for switching to the target BWP is met according to a determination that the initial BWP does not support the at least one feature.

27. Determining whether the condition for switching to the target BWP is satisfied includes: performing random access on an active BWP configured with common RACH resources; and determining that the condition for switching to the target BWP is met according to a determination that a number of random access failures on the active BWP exceeds a count threshold.

28. Receiving the configuration information includes: The configuration information is Radio Resource Control (RRC) signaling; Media Access Control (MAC) signaling, or A method according to any one of claims 19 to 27, comprising receiving via one of physical (PHY) signalling.

29. The method according to any one of claims 19 to 28, wherein the first device is a terminal device and the second device is a network device.

30. 1. A method comprising: transmitting, at a second device, configuration information to a first device indicating a set of bandwidth portions (BWPs) and a set of random access channel (RACH) configurations for the set of BWPs; The method includes performing random access with the first device on a target BWP, the random access procedure being triggered based on at least one characteristic, the target BWP being configured with RACH resources for the at least one characteristic.

31. 31. The method of claim 30, wherein the set of RACH configurations further includes the conditions for switching to the target BWP.

32. The at least one feature is decreased ability, Small data transmission, Coverage extension, or 31. The method of claim 30, comprising one of the slices.

33. The method of any of claims 30 to 32, wherein the condition indicates a first Reference Signal Received Power (RSRP) threshold for coverage extension.

34. The method of any of claims 30 to 32, wherein the condition indicates a second RSRP threshold associated with reduced performance.

35. Transmitting the configuration information The configuration information is Radio Resource Control (RRC) signaling; Media Access Control (MAC) signaling, or A method according to any one of claims 30 to 34, comprising transmitting via one of the physical (PHY) signalling.

36. The method according to any one of claims 30 to 35, wherein the first device is a terminal device and the second device is a network device.

37. An apparatus comprising: means for receiving configuration information from a second device indicating a set of Bandwidth Partitions (BWPs) and a set of Random Access Channel (RACH) configurations for the set of BWPs; means for determining that a random access procedure has been triggered based on at least one characteristic; means for determining whether a condition for switching to a target BWP is met based on the set of RACH configurations, the target BWP being configured with RACH resources for the at least one characteristic; and and means for performing the random access with the second device on the target BWP in accordance with a determination that the condition is satisfied.

38. An apparatus comprising: means for transmitting, at the second device, configuration information to the first device indicating a set of Bandwidth Partitions (BWPs) and a set of Random Access Channel (RACH) configurations for the set of BWPs; and means for performing random access with the first device on a target BWP, the random access procedure being triggered based on at least one characteristic, the target BWP being configured with RACH resources for the at least one characteristic.

39. A computer readable medium comprising program instructions for causing an apparatus to perform a method according to any one of claims 19 to 29 or any one of claims 30 to 36.

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