Random access with bandwidth part switch

Abstract

To provide improved random access operations from which various communication systems may benefit.SOLUTION: Certain embodiments may benefit from improved random access in which multiple bandwidth parts are configured to user equipment within one cell. A method, in certain embodiments, may include triggering a random access procedure at user equipment. The method may also include switching at the user equipment from a first uplink bandwidth part that does not support a random access channel to a second uplink bandwidth part that has the random access channel configured after the triggering of the random access procedure. The switching may be autonomously performed by the user equipment. In addition, the method may include performing the random access procedure at the user equipment using the random access channel configured at the second uplink bandwidth part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Various communication systems can benefit from an improved random access operation. For example, certain embodiments can benefit from an improved random access in which a plurality of bandwidth portions are configured for user equipment within one cell.

Background Art

[0002] In Third Generation Partnership Project (3GPP (registered trademark)) technologies such as Long Term Evolution (LTE) and Evolved LTE (LTE-A), once a user equipment (UE) synchronizes with the network, the UE can start accessing network services. The random access procedure is typically used to synchronize the UE with the network in the uplink direction via a Physical Random Access Channel (PRACH). The random access procedure may be a contention-based random access procedure or a non-contention / non-collision random access procedure.

[0003] When multiple UEs attempt to access the network simultaneously, a contention-based random access procedure can be used. Using a contention-based random access procedure, potential collisions between multiple UEs can be resolved and the UE can also be synchronized with the network. This contention-based random access procedure can include four separate messages transmitted between the UE and the network. The UE first sends a first message having a random access channel preamble including a Random Access Radio Network Temporary Identifier (RA-RNTI). Then, the network entity decodes the received RA-RNTI and responds by sending a random access response in a second message. The random access response generally includes a Temporary Cell Radio Network Temporary Identifier (C-RNTI), a timing advance value, and an uplink grant resource.

[0004] The UE synchronizes with the network using its timing advance value and transmits a Radio Resource Control (RRC) connection request in a third message using a temporary C-RNTI. The UE also includes a random value or a temporary Mobile Subscriber Identifier (TMSI) in the third message, which can be used by the network to determine a new C-RNTI if the temporary C-RNTI has been assigned to multiple UEs. Then, the network entity can respond with a contention resolution message or an RRC connection setup message including the new C-RNTI. The new C-RNTI is used by both the UE and the network entity to exchange data with each other while the UE remains in the connected RRC state.

[0005] The system bandwidth of a given cell, used by both the network entity and the UE for both downlink and uplink transmissions, may be divided into one or more bandwidth parts. For a pair of spectrums, the downlink bandwidth part and the uplink bandwidth part (BWP) are configured separately and respectively for each serving cell's UE. A pair of spectrums is characterized by a block of spectrum in the lower frequency band associated with a block of spectrum in the upper frequency band using Frequency Division Duplexing (FDD). On the other hand, for a non-paired spectrum using Time Division Duplexing (TDD), the downlink BWP and the uplink BWP are configured jointly as a pair but share the same center frequency.

[0006] In a primary cell, for example, the random access channel can be configured for each uplink BWP, and each downlink BWP must have a common search space (CSS) for random access responses. If some BWPs of the primary cell are not configured by the RACH, at least the initial BWP supports the random access channel. In 3GPP (registered trademark) fifth generation (5G) or New Radio (NR) technology, the number of scheduling requests can be counted. When the number of scheduling requests exceeds the maximum value of scheduling request transmissions, the user equipment can initiate a random access procedure in the same manner as LTE or LTE-A.

Summary of the Invention

[0007] According to a particular embodiment, the apparatus can include at least one memory and at least one processor including computer program code. The at least one memory and the computer program code can be configured by the at least one processor to cause the apparatus to at least trigger a random access procedure at a user equipment. The at least one memory and the computer program code can also be configured by the at least one processor to cause the apparatus to at least switch from a first uplink bandwidth part that does not support a random access channel to a second uplink bandwidth part in which the random access channel is configured after triggering the random access procedure. The switching can be performed autonomously by the apparatus. Additionally, the at least one memory and the computer program code can be configured by the at least one processor to cause the apparatus to at least execute a random access procedure using the random access channel configured in the second uplink bandwidth part.

[0008] The method of a particular embodiment can include triggering a random access procedure at a user equipment. The method can also include a switch at the user equipment from a first uplink bandwidth part that does not support a random access channel to a second uplink bandwidth part in which the random access channel is configured after triggering the random access procedure. The switch can be autonomously performed by the user equipment. Additionally, the method can include performing the random access procedure at the user equipment using the random access channel configured in the second uplink bandwidth part.

[0009] The apparatus of a particular embodiment can include means including means for triggering a random access procedure at a user equipment. The apparatus also includes means for a switch at the user equipment from a first uplink bandwidth part that does not support a random access channel to a second uplink bandwidth part in which the random access channel is configured after triggering the random access procedure. The switch can be autonomously performed by the user equipment. Additionally, the apparatus can include means for performing the random access procedure at the user equipment using the random access channel configured in the second uplink bandwidth part.

[0010] According to a particular embodiment, the apparatus can include a non-transitory computer-readable medium encoded with instructions that, when executed in hardware, execute a process. The process can include triggering a random access procedure at a user equipment. The process can also include a switch at the user equipment from a first uplink bandwidth part that does not support a random access channel to a second uplink bandwidth part in which the random access channel is configured after triggering the random access procedure. The switch can be autonomously performed by the user equipment. Additionally, the process can include performing the random access procedure at the user equipment using the random access channel configured in the second uplink bandwidth part.

[0011] According to certain other embodiments, a computer program product may be encoded by instructions for performing a process. The process may include triggering a random access procedure at a user equipment. The process may also include switching at the user equipment from a first uplink bandwidth portion that does not support a random access channel to a second uplink bandwidth portion in which a random access channel is configured after triggering the random access procedure. The switching may be performed autonomously by the user equipment. Additionally, the process may include performing a random access procedure at the user equipment using the random access channel configured in the second uplink bandwidth portion.

[0012] For a proper understanding of the present invention, reference should be made to the accompanying drawings.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0014] Certain embodiments can include beam failure detection. When a beam failure is detected, the UE can send a beam recovery request. When the number of consecutive detected beam failure instances exceeds a given threshold, a beam recovery request can be triggered or initiated. The threshold can be defined, for example, as a block error rate (BLER). Some embodiments can have one or more thresholds. In embodiments with multiple thresholds, for example, one threshold can be for the synchronization signal block (SSB), while the other threshold can be for the channel state information reference signal (CSI-RS). In NR technology, a network entity, such as a 5G or NR NodeB (gNB), can uniquely identify the user equipment from a beam failure recovery request using a PRACH sequence provided by the network to the UE.

[0015] To determine a dedicated PRACH resource for beam failure recovery, specific parameters related to the UE can be configured. For example, parameters related to the preamble sequence, such as the root sequence, cyclic shift, and / or preamble index, can be set. In another example, the maximum number of transmissions, the maximum number of power ramping, the target received power, the retransmission power ramping step size, and / or the UE's beam failure recovery timer can be configured. In some embodiments, dedicated PRACH resource parameters can also be configured. For example, frequency position information, time position, and / or related SSB or CSI-RS information. When the beam failure activation is satisfied, the UE can send a dedicated PRACH preamble to recover the link via a random access procedure.

[0016] In some embodiments, only a subset of the total uplink bandwidth portion can support random access procedures via a Physical Random Access Channel (PRACH), also referred to below as the Random Access Channel (RACH). Thus, the UE can be restricted to performing random access procedures only towards the Primary Cell (PCell) or the Primary Secondary Cell (PSCell) within a subset of the uplink bandwidth portion. Certain embodiments can enable a UE in RRC connected mode to handle UE-based triggers for random access procedures when the network is unaware of such events. In other words, even if the current active BWP, which may be referred to as the first uplink BWP, does not support the random access channel, the UE may be able to autonomously trigger random access procedures.

[0017] For example, when a random access procedure is triggered by the UE and the currently active BWP does not support the random access channel, certain embodiments enable the UE to autonomously switch to another uplink BWP, which can be referred to as a second uplink BWP on which the random access channel is configured. A UE performing the switch autonomously can mean that the switch can be performed without any knowledge or involvement from the network. Since the currently active BWP does not support and / or is not configured for RACH, the network may not be aware that the UE is attempting to initiate a random access procedure. The first uplink BWP and the second uplink BWP may be different.

[0018] FIG. 1 shows an example of a flowchart according to a particular embodiment. In particular, FIG. 1 shows an example of a user equipment executing a method or process. In step 110, the UE can trigger a random access procedure. The random access procedure may be triggered via the RACH. The UE may be in the RRC connected state during the trigger of the random access procedure. As shown in step 150, the UE can switch from a first uplink BWP that does not support the random access channel to a second uplink BWP in which the random access channel is configured. In other words, the second uplink BWP may already have a configured RACH.

[0019] In a particular embodiment where multiple uplink BWPs support the random access channel, a network entity such as a gNB can determine on which uplink BWP the UE must initiate the random access channel. The multiple BWPs may be configured for the UE in a single cell. The network entity may be included, for example, in the PCell or PSCell. The network entity can send the determination of the uplink BWP to the UE as part of the configuration instruction. As shown in step 120, the UE can receive the configuration instruction from the network entity. Based on the configured instruction, the UE can select the second uplink BWP from the multiple BWPs as shown in step 130. In some other embodiments, the UE can receive configuration information from the network entity before the trigger of the random access procedure in step 110, as shown in step 120.

[0020] In other embodiments, the separate or second uplink bandwidth part may be determined by the UE without a configuration indicated by the network entity as shown in step 140. For example, the second uplink bandwidth part may be determined by the UE based on at least one of the numerology and / or the frequency of the random access channel. The numerology may be the subcarrier spacing. The NR technology supports multiple numerology options related to multiple subcarrier spacings. The subcarrier spacing may be, for example, 15, 30, 60, 120, and 240 kilohertz (kHz). The UE can determine the second BWP based on any of the above multiple numerology options and / or the frequency used by the BWP. In some embodiments, the UE can be configured by at least a default BWP from multiple BWPs. The UE can determine the second BWP based on whether it is the default BWP or not.

[0021] As described above, in step 140, the user equipment selects the second uplink BWP. In some embodiments, the second BWP can be selected based on the UE implementation and / or based on the default and / or initial BWP. The default and / or initial BWP can be configured for other purposes such as energy efficiency and can be used as a fallback for RACH. The selection based on the UE implementation can mean that it depends on the UE implementation whether to select the BWP of the cell configuring the RACH. In yet another embodiment, the UE can select the second BWP based on the logical channel or the priority of the logical channel that triggers the random access procedure. For example, some logical channels can be restricted to be mapped to an uplink channel with a specific subcarrier spacing, and thus, the BWP having a RACH that supports the specific subcarrier spacing to which the logical channel is restricted can be prioritized.

[0022] Once the second BWP is selected, as shown in step 140, the user equipment can switch from a first uplink bandwidth part that does not support the random access channel to a second uplink bandwidth part in which the random access channel is configured, as shown in step 150. The switching from the first uplink bandwidth part to the second uplink bandwidth part may be autonomously performed by the user equipment. In some embodiments, the network may not even be aware that the UE is performing a random access procedure. The switching exemplified in step 150 may include the UE autonomously deactivating the first uplink BWP and activating the second uplink BWP.

[0023] In certain embodiments, one or more uplink carriers can share the same uplink timing alignment and can be grouped into the same timing advance group (TAG). To prevent the UE from transmitting any uplink signals other than those related to the random access procedure, the time alignment timer (TAT) may be considered expired. In some embodiments, the TAT may be associated with a TAG that includes the first BWP and the second BWP. In other words, the TAT associated with a TAG that includes the first BWP and / or the second BWP may be considered expired to prevent the UE from transmitting any signals on the first BWP. Thus, the UE is not able to transmit any signals on the first BWP until it receives a new timing advance value from the network. The new timing advance value can be received through a random access procedure in which the time alignment timer is restarted. A signal that the UE can attempt to transmit, for example, on the first BWP can be in response to a downlink allocation or an uplink grant received by the UE from a network entity that is unaware of the ongoing random access procedure.

[0024] In step 160, the UE can switch the active downlink BWP along with the switching from the first uplink bandwidth part shown in step 150 to the second uplink bandwidth part. For example, when the triggered random access procedure is a contention-based random access procedure, the active downlink BWP is switched along with the switching from the first uplink BWP to the second uplink BWP. For example, when the maximum number of media access control (MAC) layer scheduling requests is reached, a contention-based random access procedure may be triggered. The switching of the active downlink BWP along with the second uplink BWP can be performed so that the downlink BWP can correspond to the BWP that the UE expects to receive a random access response from the network entity. Since it may not be possible for the network to identify the UE from the received preamble, the random access response may need to be transmitted on a known downlink BWP. Such a downlink BWP may be at least one of the downlink BWPs having CSS.

[0025] On the other hand, certain embodiments can utilize a contention-free random access procedure. This random access procedure can be triggered, for example, after a beam failure is detected by the UE or after a beam recovery request is transmitted by the UE. In the contention-free random access procedure, similar to the contention-based random access procedure, the UE can switch the active downlink BWP along with the switching of the first uplink bandwidth part to the second uplink bandwidth part. However, in other embodiments, the UE can maintain the current downlink BWP of the contention-free random access procedure regardless of whether the first uplink BWP is switched.

[0026] In certain embodiments, whether a UE switches or retains a downlink BWP in a contention-free random access procedure can be configured by the network or a network entity therein. A network in such an embodiment may identify the UE from the received preamble and may be able to respond in a previous downlink BWP. Some embodiments where the network determines the retention or switching of the downlink BWP may be used in paired spectra where the downlink and uplink BWPs are configured or switched individually. In some embodiments, the previous downlink BWP can have a CSS, while in some other embodiments of the previous downlink BWP, the BWP can only have a UE-specific search space (USS).

[0027] In step 170, the UE can receive a contention resolution message from a network entity as part of a random access procedure. The contention resolution message is the fourth message of a contention-based random access procedure. A switch of at least one of the uplink BWP and / or the downlink BWP may occur upon reception of the contention resolution message at the UE. In some embodiments, the contention resolution message is sent directly towards the C-RNTI of the UE, in which case, a switch of at least one of the uplink BWP and / or the downlink BWP can be performed. In step 180, the UE can execute a random access procedure using a random access channel configured with a second uplink bandwidth part. The described embodiments help prevent incorrect network scheduling when the UE has already triggered a random access procedure. This reduces the amount of resources used by the network, thereby enhancing the functionality of the network as a whole and the network entities contained within the network.

[0028] Figure 2 shows a system according to a particular embodiment. It should be understood that each block in FIG. 1 can be implemented by various means such as hardware, software, firmware, one or more processors and / or circuits, or combinations thereof. In one embodiment, the system can include several devices such as, for example, network entity 220 or UE 210. The system can include two or more UEs 210 and two or more network entities 220, but only one network entity is shown for illustrative purposes. The network entity can be any of a network node, access node, base station, evolved NodeB (eNB), gNB, server, host, or other access or network node described herein.

[0029] Each of these devices can include at least one processor, control device, or module shown as 211 and 221 respectively. At least one memory can be provided for each device, shown as 212 and 222 respectively. The memory can include computer program instructions or computer code stored therein. One or more transceivers 213 and 223 can be provided, and each device can also include antennas illustrated as 214 and 224 respectively. Only one antenna is shown for each, but multiple antennas and multiple antenna elements can be provided for each device. Higher category UEs generally include multiple antenna panels. For example, other configurations of these devices can also be provided. For example, network entity 220 and UE 210 can be additionally configured for wired communication in addition to wireless communication. In this case, antennas 214 and 224 can illustrate any form of communication hardware, not just antennas.

[0030] Transceivers 213 and 223 can each be, independently, a unit or device that can be configured for a transmitter, a receiver, or both a transmitter and a receiver, or both transmitting and receiving. In other embodiments, a UAV or network entity can have at least one separate receiver or transmitter. The transmitter and / or receiver (to the extent radio components are concerned) can also be implemented as a remote radio head, for example, located on a mast rather than on the device itself. Operations and functionality can be performed in a flexible manner in different entities such as nodes, hosts, or servers. In other words, the division of labor can vary on a case-by-case basis. One possible usage is to have a network node distribute local content. One or more functionalities can also be implemented as virtual applications (s) of software that can be executed on a server.

[0031] The user device or user equipment can be a mobile station (MS) such as a mobile phone, smartphone, or multimedia device, a computer such as a tablet with wireless communication capabilities, a personal data or personal digital assistant (PDA) with wireless communication capabilities, a portable media player with wireless communication capabilities, a digital camera, a pocket video camera, a navigation unit, or any combination thereof. In other embodiments, the UE can be a machine type communication (MTC) device or an Internet of Things device, which may not require human interaction such as a sensor, meter, or actuator. The method and / or process shown in FIG. 1 can be performed by the user equipment 210.

[0032] In some embodiments, an apparatus, such as user equipment 210 or network entity 220, can include means for performing the above-described embodiments with respect to FIG. 1. In certain embodiments, at least one memory containing computer program code can be configured to cause the apparatus, by at least one processor, to perform at least any of the processes described herein. The apparatus can be, for example, user equipment 210 or network entity 220.

[0033] Processors 211 and 221 can be implemented by any computing or data processing device, such as a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), a digital extension circuit or equivalent device, or a combination thereof. The processor can be implemented as a single controller or multiple controllers or processors.

[0034] For firmware or software, the implementation can include at least one module or unit of a chipset (e.g., procedures, functions, etc.). Memories 212 and 222 can each be any suitable storage device, such as a non-transitory computer-readable medium. A hard disk drive (HDD), random access memory (RAM), flash memory, or other suitable memory may be used. The memory may be coupled to a single integrated circuit as a processor or separated therefrom. Further, computer program instructions may be stored in a memory that can be processed by a processor and can be in any suitable form of computer program code, such as a compiled or translated computer program written in any suitable programming language. The memory or data storage entity is usually built-in but may be external or a combination thereof, for example, when additional storage capacity is obtained from a service provider. The memory may be fixed or removable.

[0035] The memory and computer program instructions can be configured to cause a hardware device, such as network entity 220 or UE 210, to execute any of the above processes (e.g., see FIG. 1) by a processor for a particular device. Thus, in a particular embodiment, a non-transitory computer-readable medium can be encoded by computer instructions or one or more computer programs (e.g., added or updated software routines, applets, or macros) that can execute a process, such as one of the processes described herein, when executed in hardware. The computer program can be encoded in a programming language, which can be a high-level programming language, such as Objective-C, C++, C#, Java, etc., or a low-level programming language, such as machine language or assembler. Alternatively, a particular embodiment may be executed entirely in hardware.

[0036] Furthermore, although FIG. 2 illustrates a system including network entity 220 and UE 210, particular embodiments may be applicable to other configurations and configurations including other elements as described and illustrated herein. For example, there may be multiple user equipment devices and multiple network entities, or other nodes providing similar functionality, such as nodes that combine the functionality of network entities such as user equipment and relay nodes. Similarly, UE 210 may be equipped with various configurations for communication other than communication network entity 220. For example, UE 210 can be configured for device-to-device, machine-to-machine, and / or vehicle-to-vehicle transmissions.

[0037] The above-described embodiments can provide significant improvements to the functionality of the network and / or to the functionality of network entities included within user equipment and the network. Specifically, according to particular embodiments, a user equipment may be able to perform a random access procedure even when it is active or when a first uplink BWP does not support a random access channel. The UE can switch the first uplink BWP to a second BWP in which a random access channel is configured. Doing so helps prevent the error that the network can schedule UEs that have already failed a scheduling request and / or UEs that have already triggered a random access procedure.

[0038] Preventing such incorrect scheduling helps reduce the resources utilized by the network, thereby significantly improving the overall efficiency and throughput of the network. This efficiency improvement not only improves the functionality of network entities included within the network, but also significantly improves the functionality of user equipment by preventing unnecessary transmissions. For example, reducing unnecessary transmissions by the network can help reduce the amount of battery consumed by the user equipment.

[0039] The features, structures, or characteristics of the specific embodiments described throughout this specification can be incorporated in any suitable manner into one or more embodiments. For example, the use of phrases such as "specific embodiments", "some embodiments", "other embodiments" throughout this specification or other similar language indicates the fact that the specific features, structures, or characteristics described in relation to the embodiments can be included in at least one embodiment of the present invention. Thus, the appearance of phrases such as "in a specific embodiment", "in some embodiments", "in other embodiments" throughout this specification or other similar language is not necessarily related to the same group of embodiments, and the described features, structures, or characteristics can be incorporated in any suitable manner into one or more embodiments.

[0040] A person skilled in the art can easily understand that the present invention described above can be implemented by steps in a different order and / or by hardware elements having a configuration different from the disclosed configuration. Therefore, although the present invention is described based on these preferred embodiments, it is clear to a person skilled in the art that specific modifications, variations, and alternative structures are obvious and remain within the scope of the present invention. Although many of the above embodiments relate to 3GPP (registered trademark) 5G or NR technology, the embodiments can be applied to any other 3GPP (registered trademark) technology, such as fourth generation (4G), third generation (3G), LTE, LTE-A, and / or the Internet of Things.

[0041] Glossary of partial terms 3GPP (registered trademark) Third Generation Partnership Project 5G Fifth Generation NR New Radio technology gNB NR Node B UE User Equipment LTE Long Term Evolution LTE-A Evolutionary LTE PRACH Physical Random Access Channel RA-RNTI: Random Access Radio Network Temporary Identifier C-RNTI: Cell Radio Network Temporary Identifier RRC: Radio Resource Control TMSI: Temporary Mobile Subscriber Identity FDD: Frequency Division Duplexing BWP: Bandwidth Part TDD: Time Division Duplexing CSS: Common Search Space USS: UE-Specific Search Space BLER: Block Error Rate SSB: Synchronization Signal Block CSI-RS: Channel State Information Reference Signal PCell: Primary Cell PSCell: Primary and Secondary Cell TAG: Timing Advance Group

Claims

1. Triggering a random access procedure at a user equipment; At the user equipment, switching from a first uplink bandwidth part that does not support a random access channel to a second uplink bandwidth part having the random access channel configured after the triggering of the random access procedure, wherein the switching is autonomously performed by the user equipment; At the user equipment, performing the random access procedure using the random access channel configured in the second uplink bandwidth part; A method comprising the above.

2. The method according to claim 1, wherein the switching comprises the user equipment autonomously deactivating the first uplink bandwidth part and activating the second uplink bandwidth part.

3. The method according to claim 1 or 2, wherein a timing alignment timer is considered to have expired.

4. The method according to claim 3, wherein the timing alignment timer is associated with a timing alignment group comprising at least one of the first uplink bandwidth part and the second uplink bandwidth part.

5. The method according to any one of claims 1 to 4, further comprising, at the user equipment, switching an active downlink bandwidth part together with the switching from the first uplink bandwidth part to the second uplink bandwidth part.

6. The method according to claim 5, wherein the switching of the first downlink bandwidth part occurs when the triggered random access procedure is at least one of a contention-based random access procedure or a contention-free random access procedure.

7. The method according to any one of claims 1 to 6, further comprising, at the user equipment, receiving a contention resolution message from a network entity as part of the random access procedure, wherein the switching of at least one of the first uplink bandwidth part or the downlink bandwidth part occurs in response to the reception of the contention resolution message.

8. At the user equipment, receiving a configuration instruction from the network entity; selecting the second uplink bandwidth part from a plurality of bandwidth parts based on the configuration indication; The method according to any one of claims 1 to 7, further comprising.

9. The method according to claim 8, wherein the plurality of bandwidth parts are configured for the user equipment in a single cell.

10. The method according to any one of claims 1 to 9, further comprising, in the user equipment, selecting the second uplink bandwidth part based on at least one of the implementation of the user equipment, the default or initial bandwidth part, the logical channel triggering the random access procedure, or the priority of the logical channel.

11. The method according to any one of claims 1 to 10, further comprising, by the user equipment, selecting the second uplink bandwidth part based on at least one of cryptography or the frequency of the random access channel.

12. The method according to any one of claims 1 to 11, wherein the network entity may be included in a primary cell or a secondary cell.

13. The method according to any one of claims 1 to 12, wherein the user equipment is in a radio resource control connection state during the triggering of the random access procedure.

14. The method according to any one of claims 1 to 13, wherein the triggering of the random access procedure occurs after a beam failure is detected by the user equipment.

15. at least one processor; a device comprising at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to cause the at least one processor to cause the device to perform at least a process, the process comprising triggering a random access procedure; switching from a first uplink bandwidth part that does not support a random access channel to a second uplink bandwidth part having the random access channel configured after the triggering of the random access procedure, wherein the switching is autonomously performed by the device; performing the random access procedure using the second uplink bandwidth part; The device comprising.

16. The apparatus according to claim 15, comprising the apparatus configured to autonomously invalidate the first uplink bandwidth portion and activate the second uplink bandwidth portion by the switching.

17. The at least one memory and the computer program code cause the apparatus, by the at least one processor, to at least The apparatus according to claim 15 or 16, configured to cause the active downlink bandwidth portion to be switched together with the switching from the first uplink bandwidth portion to the second uplink bandwidth portion.

18. The at least one memory and the computer program code cause the apparatus, by the at least one processor, to at least receive a configuration instruction from a network entity, The apparatus according to any one of claims 15 to 17, configured to cause the second uplink bandwidth portion to be selected from a plurality of bandwidth portions based on the configuration instruction.

19. The at least one memory and the computer program code cause the apparatus, by the at least one processor, to at least The apparatus according to any one of claims 15 to 18, configured to cause the second uplink bandwidth portion to be selected based on at least one of the implementation of the apparatus, the default or initial bandwidth portion, the logical channel triggering the random access procedure, or the priority of the logical channel.

20. The apparatus according to any one of claims 15 to 19, wherein the apparatus is in a radio resource control connection state during the triggering of the random access procedure.

21. An apparatus comprising 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 the apparatus to execute, by the at least one processor, a process including the method according to any one of claims 3, 4, 6, 7, 9, and 11 to 14.

22. A non-transitory computer-readable medium encoded by instructions that, when executed in hardware, execute a process, wherein the process includes the method according to any one of claims 1 to 14. The non-transitory computer-readable medium. **Claim 23** An apparatus comprising means for executing a process comprising the method according to any one of claims 1 to 14. **Claim 24** A computer program product encoded by instructions for executing a process comprising the method according to any one of claims 1 to 14. **Claim 25** A computer program product implemented on a non-transitory computer-readable medium and encoded by instructions that, when executed in hardware, execute a process comprising the method according to any one of claims 1 to 14.

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