WO2022198500A1

WO2022198500A1 - Random access processing method and user equipment

Info

Publication number: WO2022198500A1
Application number: PCT/CN2021/082742
Authority: WO
Inventors: Aijuan Feng; Jia SHENG
Original assignee: JRD Communication (Shenzhen) Ltd.
Priority date: 2021-03-24
Filing date: 2021-03-24
Publication date: 2022-09-29
Also published as: CN116889074A

Abstract

A random access processing method is disclosed. A user equipment (UE) selects a synchronization signal block (SSB) associated with a subset in a set of one or more random access channel occasions (ROs) for transmitting a random access signaling message in a random access procedure. The UE determines whether to retune a frequency range of the UE or not based on a relationship between the frequency range of the UE and one RO selected from the set of the one or more ROs. The UE transmitting the random access signaling message through the selected RO. The SSB may be selected based on the relationship between the frequency range of the UE and the selected RO. The UE retunes the frequency range of the UE to cover the selected RO when a frequency span of the selected RO is not in the frequency range of the UE.

Description

RANDOM ACCESS PROCESSING METHOD AND USER EQUIPMENT

Technical Field

The present disclosure relates to the field of communication systems, and more particularly, to a random access processing method and user equipment.

Background Art

Wireless communication systems, such as the third-generation (3G) of mobile telephone standards and technology are well known. Such 3G standards and technology have been developed by the Third Generation Partnership Project (3GPP) . The 3rd generation of wireless communications has generally been developed to support macro-cell mobile phone communications. Communication systems and networks have developed towards being a broadband and mobile system. In cellular wireless communication systems, user equipment (UE) is connected by a wireless link to a radio access network (RAN) . The RAN comprises a set of base stations (BSs) which provide wireless links to the UEs located in cells covered by the base station, and an interface to a core network (CN) which provides overall network control. As will be appreciated the RAN and CN each conduct respective functions in relation to the overall network. The 3rd Generation Partnership Project has developed the so-called Long Term Evolution (LTE) system, namely, an Evolved Universal Mobile Telecommunication System Territorial Radio Access Network, (E-UTRAN) , for a mobile access network where one or more macro-cells are supported by a base station known as an eNodeB or eNB (evolved NodeB) . More recently, LTE is evolving further towards the so-called 5G or NR (new radio) systems where one or more cells are supported by a base station known as a gNB.

Technical Problem

Beams are used in the random access procedure in NR, where one synchronization signal block (SSB) has multiple transmission opportunities in the time domain, and has a corresponding number, which can correspond to one of different beams. A UE has the opportunity to send Preamble when the SSB's beam scan signal covers the UE.

When receiving a preamble from a UE, the network knows the optimal downlink beam to the UE. In other words, it knows which wave speed is pointing to the UE, so the SSB needs to be associated with the preamble, and the preamble is sent under the context of RACH occasion.

The RO configuration with Msg1-FDM=8 for SCS 30 and 120 kHz requires a bandwidth of 35 MHz and a bandwidth of 138 MHz respectively. As the maximum bandwidth of RedCap UE was agreed as 20 MHz for FR1 and 100 MHz for FR2, the total frequency span of 8 PRACH occasions is greater than the UE bandwidth. Consequently, a RACH occasion (RO) also know as physical random access channel (PRACH) occasion associated with the best SSB can fall outside the UE bandwidth.

Another potential issue with the bandwidth reduction is related to the frequency hopping for PUCCH and PUSCH in the initial uplink BWP during the initial access procedure. PUCCH is used for carrying the ACK/NACK for Msg4. In this case, frequency hopping is configured, and the PRBs used for PUCCH are determined based in the initial UL BWP configuration, which may have a bandwidth larger than the maximum RedCap UE bandwidth. A similar problem exists for Msg3 PUSCH if frequency hopping is configured for PUSCH.

Technical Solution

An objective of the present disclosure is to propose a random access processing method and user equipment.

A first aspect of the disclosure provides a random access processing method executable in a user equipment (UE) , comprising:

receiving and identifying random access channel (RACH) related configuration to obtain RACH related resources; and

selecting one resource from the RACH related resources for transmitting a RACH related message, wherein selection of the RACH related resources is prioritized based on whether a RACH related transition operation is required following selection of one resource such that a resource in the RACH related resources not requiring a RACH related transition operation is prioritized over another resource in the RACH related resources requiring a RACH related transition operation in the selecting of the RACH related resources.

A second aspect of the disclosure provides a user equipment (UE) comprising a processor. The processor is configured to execute:

The disclosed method may be implemented in a chip. The chip may include a processor, configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute the disclosed method.

The disclosed method may be programmed as computer executable instructions stored in non-transitory computer readable medium. The non-transitory computer readable medium, when loaded to a computer, directs a processor of the computer to execute the disclosed method.

The non-transitory computer readable medium may comprise at least one from a group consisting of: a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a Read Only Memory, a Programmable Read Only Memory, an Erasable Programmable Read Only Memory, EPROM, an Electrically Erasable Programmable Read Only Memory and a Flash memory.

The disclosed method may be programmed as computer program product, that causes a computer to execute the disclosed method.

The disclosed method may be programmed as computer program, that causes a computer to execute the disclosed method.

Advantageous Effects

The UE selects one resource from the RACH related resources for transmitting a RACH related message, where the UE prioritizes RACH related resources based on whether an RACH related transition operation is required following the selection of one resource during the selecting of RACH related resources such that a resource in the RACH related resources not requiring an RACH related transition operation is prioritized over another resource in the RACH related resources requiring an RACH related transition operation in the selecting of RACH related resources. The invention provides embodiments with various options, such as proper RF-retuning and separate initial UL BWP (s) . These specific methods enable UE bandwidth to include a frequency range of a PRACH occasion associated with the best SSB, a frequency range of PUCCH for Msg4/MsgB HARQ feedback, and/or a frequency range of PUSCH for Msg3/MsgA during initial access.

Description of Drawings

In order to more clearly illustrate the embodiments of the present disclosure or related art, the following figures will be described in the embodiments are briefly introduced. It is obvious that the drawings are merely some embodiments of the present disclosure, a person having ordinary skill in this field can obtain other figures according to these figures without paying the premise.

FIG. 1 illustrates a schematic view of a telecommunication system.

FIG. 2 illustrates a schematic diagram showing a random access processing method according to an embodiment of the invention.

FIG. 3 illustrates a schematic diagram showing an embodiment of the random access processing method.

FIG. 4 illustrates a schematic diagram showing another embodiment of the random access processing method.

FIG. 5 illustrates a schematic diagram showing RF-retuning for preamble transmission using a selected RACH occasion.

FIG. 6a illustrates a schematic diagram showing an example of ROs having RO frequency offsets measured from the lowest PRB of an initial UL BWP.

FIG. 6b illustrates a schematic diagram showing an example of ROs having RO frequency offsets measured from the center frequency of an initial UL BWP.

FIG. 7 illustrates a schematic diagram showing an example of determining a relationship between an RO and the frequency range of the UE

FIG. 8 illustrates a schematic diagram showing an example of switching between initial UL BWPs.

FIG. 9 illustrates a schematic diagram showing offsets between ROs and two initial UL BWPs.

FIG. 10 illustrates a schematic diagram showing an example of multiple UL BWPs with separate RACH configurations where one RO is within UE bandwidth.

FIG. 11A illustrates a schematic diagram showing an example of selecting SSB with qualified RO.

FIG. 11B illustrates a schematic diagram showing an example of selecting SSB with qualified RO.

FIG. 12A illustrates a schematic diagram showing a first embodiment of selecting SSB with qualified reference signal receiving power (RSRP) and qualified RO.

FIG. 12B illustrates a schematic diagram showing a second embodiment of selecting SSB with an alternative secondary factor in the criteria for SSB selection.

FIG. 12C illustrates a schematic diagram showing a third embodiment of selecting SSB with an alternative secondary factor in the criteria for SSB selection.

FIG. 13 illustrates a schematic diagram showing PUSCH resources for 1st hop and 2nd hop.

FIG. 14 illustrates a schematic diagram showing an example of applying the different interpretations for the 2nd hop frequency offset.

FIG. 15 illustrates a schematic diagram showing an example of PUCCH RF-retuning.

FIG. 16 illustrates a schematic view showing a system for wireless communication according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the disclosure are described in detail with the technical matters, structural features, achieved objects, and effects with reference to the accompanying drawings as follows. Specifically, the terminologies in the embodiments of the present disclosure are merely for describing the purpose of the certain embodiment, but not to limit the disclosure.

With reference to FIG. 1, a telecommunication system including a UE 10a, a UE 10b, a base station (BS) 200a, and a network entity device 300 executes the disclosed method according to an embodiment of the present disclosure. FIG. 1 is shown for illustrative not limiting, and the system may comprise more UEs, BSs, and CN entities. Connections between devices and device components are shown as lines and arrows in the FIGs. The UE 10a may include a processor 11a, a memory 12a, and a transceiver 13a. The UE 10b may include a processor 11b, a memory 12b, and a transceiver 13b. The base station 200a may include a processor 201a, a memory 202a, and a transceiver 203a. The network entity device 300 may include a processor 301, a memory 302, and a transceiver 303. Each of the

processors

11a, 11b, 201a, and 301 may be configured to implement proposed functions, procedures and/or methods described in the description. Layers of radio interface protocol may be implemented in the

processors

11a, 11b, 201a, and 301. Each of the

memory

12a, 12b, 202a, and 302 operatively stores a variety of programs and information to operate a connected processor. Each of the

transceivers

13a, 13b, 203a, and 303 is operatively coupled with a connected processor, transmits and/or receives radio signals or wireline signals. The UE 10a may be in communication with the UE 10b through a sidelink. The base station 200a may be an eNB, a gNB, or one of other types of radio nodes, and may configure radio resources and for the UE 10a and UE 10b.

Each of the

processors

11a, 11b, 201a, and 301 may include an application-specific integrated circuits (ASICs) , other chipsets, logic circuits and/or data processing devices. Each of the

memory

12a, 12b, 202a, and 302 may include a read-only memory (ROM) , a random access memory (RAM) , a flash memory, a memory card, a storage medium and/or other storage devices. Each of the

transceiver

13a, 13b, 203a, and 303 may include baseband circuitry and radio frequency (RF) circuitry to process radio frequency signals. When the embodiments are implemented in software, the techniques described herein can be implemented with modules, procedures, functions, entities and so on, that perform the functions described herein. The modules can be stored in a memory and executed by the processors. The memory can be implemented within a processor or external to the processor, in which those can be communicatively coupled to the processor via various means are known in the art.

The network entity device 300 may be a node in a CN. CN may include LTE CN or 5G core (5GC) which includes user plane function (UPF) , session management function (SMF) , mobility management function (AMF) , unified data management (UDM) , policy control function (PCF) , control plane (CP) /user plane (UP) separation (CUPS) , authentication server (AUSF) , network slice selection function (NSSF) , and the network exposure function (NEF) .

With reference to FIG. 2, an example of the UE in the description may include one of the UE 10a or UE 10b. An example of the base station in the description may include the base station 200a. Uplink (UL) transmission of a control signal or data may be a transmission operation from a UE to a base station. Downlink (DL) transmission of a control signal or data may be a transmission operation from a base station to a UE. A UE receives and identifiesRACH related configuration to obtain RACH related resources (block 210) .

The UE selects one resource from the RACH related resources for transmitting a RACH related message, where the UE prioritizes RACH related resources based on whether an RACH related transition operation is required following the selection of one resource during the selecting of RACH related resources such that a resource in the RACH related resources not requiring an RACH related transition operation is prioritized over another resource in the RACH related resources requiring an RACH related transition operation in the selecting of RACH related resources. (block 212) . The RACH related message may comprise a random access signaling message, such as a random access uplink message. Examples of the random access uplink message may comprise a preamble for the random access procedure in msg1 or msgA, a physical uplink shared channel (PUSCH) in a msg3 or a msgA-PUSCH, and a physical uplink control channel (PUCCH) in a msg4 HARQ-ACK or a msgB during the random access procedure.

In some embodiments of the disclosed method, the RACH related configuration may comprise random access channel (RACH) configuration, physical uplink shared channel (PUSCH) configuration, physical uplink control channel (PUCCH) , and the resource of RACH related resources may comprise random access channel occasions (ROs) in a random access procedure and/or hops in a frequency domain for transmitting a random access uplink message during a subsequent portion of the random access procedure. The random access uplink message may be a preamble for the random access procedure in msg1 or msgA, a physical uplink shared channel (PUSCH) in a msg3 or a msgA-PUSCH, or a physical uplink control channel (PUCCH) in a msg4 HARQ-ACK or a msgB during the random access procedure. When RACH related resources comprise a set of one or more ROs, the set of one or more ROs may be configured in a RACH configuration. When the RACH related resources comprise a set of one or more hops for PUSCH transmission, the set of one or more hops may be configured in a PUSCH configuration. When the RACH related resources comprise a set of one or more hops for PUCCH transmission, the set of one or more hops may be configured in a PUCCH configuration.

The UE determines whether the selected resource of the RACH related resources requires a RACH related transition operation (block 214) ? In some embodiments of the disclosure, the RACH related transition may comprise UE retuning and/or bandwidth part (BWP) switching. The UE retuning adjusts a center frequency of a UE.

The selected resource of the RACH related resources may require a RACH related transition operation, for example, when the selected resource of the RACH related resources is located outside of a frequency range of the UE, or when a BWP associated with the selected resource of the RACH related resources is not the active BWP.

When the selected resource of the RACH related resources does not require a RACH related transition operation, the UE transmits a RACH related message through the selected resource of the RACH related resources (block 218) .

When the selected resource of the RACH related resources requires a RACH related transition operation, the UE performs the required RACH related transition operation. (block 216) . For example, when the selected resource of the RACH related resources is located outside of a frequency range of the UE, the UE performs UE retuning to adjust the frequency range of the UE so that the adjusted frequency range can cover the selected resource of the RACH related resources. When a preferred BWP associated with the selected resource of the RACH related resources is not the active BWP, the UE performs BWP switching to activate the selected preferred BWP as the active BWP.

After the RACH related transition operation, the UE transmits a RACH related message through the selected resource in the RACH related resources (block 218) .

This invention may be applied to a UE with limited bandwidth, such as a reduced capability (RedCAP) UE, a machine type communication (MTC) device, a narrowband internet of thing (NBIoT) device, and others. The disclosure provide embodiments to solve the problem of PRACH occasions outside the UE bandwidth.

The invention provides embodiments with various options, such as proper RF-retuning and separate initial UL BWP (s) . These specific methods enable UE bandwidth to include a frequency range of a PRACH occasion associated with the best SSB, a frequency range of PUCCH for Msg4/MsgB HARQ feedback, and/or a frequency range of PUSCH for Msg3/MsgA during initial access. Embodiments of the invention are detailed in the following.

Transmission of a RACH preamble in a RACH occasion:

In some embodiments of the disclosure, the RACH related resources may comprise random access channel occasions (ROs) for transmitting a RACH preamble in a random access procedure.

With reference to FIG. 3, the UE executes an embodiment of the random access processing method. The UE selects a synchronization signal block (SSB) associated with a subset in a set of one or more random access channel occasions (ROs) for transmitting a random access signaling message in a random access procedure (block 220) . The UE determines whether to retune a frequency range of the UE or not based on a relationship between the frequency range of the UE and one RO selected from the set of the one or more ROs (block 222) . The UE transmits the random access signaling message through the selected RO (block 224) . The frequency range of the UE may also be referred to as UE bandwidth. Retuning of the UE may be referred to as RF-retuning. A RACH occasion may be also referred to as a PRACH occasion or an RO.

Proper RF-retuning:

With reference to FIG. 4, block 222 may further comprise

blocks

2221 and 2222. The UE determines whether a frequency span of the selected RO is included in the frequency range of the UE (block 2221) . The UE retunes the frequency range of the UE to cover the selected RO when a frequency span of the selected RO is not included in the frequency range of the UE (block 2222) . The UE transmits the random access signaling message through the selected RO when a frequency span of the selected RO is included in the frequency range of the UE (block 224) .

FIG. 5 shows RF-retuning for preamble transmission using a selected RACH occasion. The UE selects an RO 310 and performs RF-retuning from a 1 ^st UE frequency range to a 2 ^nd UE frequency range that cover the selected RO 310.

UE may record a physical resource block (PRB) offset list including frequency offset between RO and a reference point, such as the lowest/center PRB of an initial UL BWP. If the RACH occasion (RO) selected by the MAC entity is out of the UE frequency range according to the PRB offset list, UE obtains a least UE retuning offset (Δf) to adjust RF center frequency of the UE in an RF-retuning operation. After retuning, UE transmits a preamble using the selected RO.

The UE obtains a location of a given RO, where the given RO may be one RO in the set of one or more ROs. The location of the given RO is represented by an RO frequency offset of the given RO with respect to a frequency domain reference point of an initial uplink (UL) bandwidth part (BWP) . The frequency domain reference point of the BWP may be a lowest frequency, a center frequency, or a first physical resource block of the initial UL BWP.

The UE may maintain in an RO offset record the RO frequency offset of the given RO to form RO frequency offsets of ROs in the set of one or more ROs, and records in a list the RO frequency offsets associated with the ROs in the set of one or more ROs. Table 1 is an example of the list.

Table 1: Offset between RO and a reference point

The following examples illustrate how to get the UE retuning offset used for retuning. RB _offset is the frequency offset in units of RBs between an RO and the reference point, and may be used to represent an RO frequency offset. RB _prach is the total number of RBs of an RO, and may be used to represent a bandwidth of the RO. FIG. 6a shows an example of ROs having RO frequency offsets measured from the lowest PRB of an initial UL BWP while a lowest PRB in the frequency range of the UE is also aligned with the lowest PRB of the initial UL BWP. FIG. 6b shows an example of ROs having RO frequency offsets measured from the center frequency of an initial UL BWP while a center frequency in the frequency range of the UE is also aligned with the center frequency of the initial UL BWP. Table 2 and Table 3 are examples of a formula (1) for a least UE retuning offset. In Table 2, the reference point is the lowest PRB of an initial UL BWP. In Table 3, the reference point is the center of the initial UL BWP respectively. If Δf _RB ≠0, UE may perform RF retuning.

Table 2: an example formula (1) for obtaining a least UE retuning offset

Table 3: an example formula (1) for obtaining a least UE retuning offset

With reference to FIG. 7, in determining a relationship between an RO and the frequency range of the UE, the block 2221 further comprises the following operations. The UE obtains a least UE retuning offset Δf _RB associated with each RO in the set of one or more ROs from the location of the RO, a bandwidth of the RO, and the frequency range of the UE (block 2221-1) . The least UE retuning offset may be represented by Δf _RB in units of RBs or Δf in Hertz (Hz) . A range of frequency switching in RF retuning performed by the UE may be greater than or equal to the least UE retuning offset. The UE determines the relationship between the frequency range of the UE and the selected RO using the least UE retuning offset (block 2221-2) .

When a RO frequency offset RB _offset of the lowest frequency of a specific RO in the set of one or more ROs is measured with respect to the lowest frequency of an initial UL BWP, the least UE retuning offset Δf _RB of the UE associated with the specific RO is calculated using a RO frequency offset RB _offset of a specific RO, a bandwidth RB _prach of a specific RO, and a bandwidth

of the frequency range of the UE according to:

if

When a RO frequency offset RB _offset of the lowest frequency of a specific RO in the set of one or more ROs is measured with respect to a center frequency of an initial UL BWP, the least UE retuning offset Δf _RB of the UE associated with the specific RO is calculated using a RO frequency offset RB _offset of a specific RO, a bandwidth RB _prach of a specific RO, and a bandwidth

of the frequency range of the UE according to:

if (RB _offset) < 0 and

Δf _RB = 0 if (RB _offset) < 0 and

if (RB _offset) ≥ 0 and

Δf _RB = 0 if (RB _offset) ≥ 0 and

The UE may maintain in a retuning offset record the UE retuning offset derived from the given RO to form UE retuning offsets of ROs in the set of one or more ROs, and records in a list the UE retuning offsets associated with the ROs in the set of one or more ROs. Table 4 is an example of the list.

Table 4: UE retuning offsets of ROs

RACH occasion index	Least UE retuning Offset
0	Δf _{RB_RO0}
1	Δf _{RB_RO1}
…	…

A UE physical layer (PHY) is a physical layer entity in the UE. A UE medium access control (MAC) layer is a MAC layer entity in the UE. The physical layer entity in the UE may select one RO as the selected RO. Alternatively, the medium access control (MAC) layer entity in the UE may select one RO as the selected RO.

Adaptation in physical layer:

1. From system information or higher layer configuration, the UE physical layer obtains a frequency location and bandwidth and RACH configuration of an initial UL BWP.

2. According to the RACH configuration, the UE obtains the number of frequency division multiplexed (FDMed) ROs, and RO frequency offsets with respective to PRB 0. The UE may record a list, such as Table 1 or Table 4, to describe offsets between ROs and the BWP reference point, such as PRB 0 or the center of the initial UL BWP.

3. The UE MAC layer selects a SSB with SSB-RSP above rsrp-ThresholdSSB, if any, or selects an SSB randomly. The UE MAC layer determines available RACH occasion (s) from the RACH occasions corresponding to the selected SSB in the association period. If the selected SSB is associated with multiple RACH occasions, the UE MAC layer may select a RACH occasion randomly with equal probability amongst the RACH occasions.

4. The UE MAC layer instructs the UE physical layer to transmit a random access preamble using the selected RACH occasion.

5. According to the higher-level configuration, the UE is provided a number N of SS/PBCH block (SSB) indexes per RO and a number of contention-based preambles per SS/PBCH block index per valid RACH occasion.

The UE physical layer obtains a least UE retuning offset represented by Δf _RB and/or Δf according to Table 1 or Table 4 and a formula, such as formula (1) in Table 2 and Table 3. If Δf _RB ≠0, the UE performs RF retuning to adjust the center frequency of the UE by an actual UE retuning offset, and the actual UE retuning offset >= Δf while the UE lowest frequency shall not exceed the lowest frequency of the selected RO.

6. UE transmits the preamble, and retunes to the original center frequency of the UE.

Adaptation in MAC layer:

1. From system information or higher layer configuration, the UE MAC layer obtains a frequency location and bandwidth and RACH configuration of an initial UL BWP.

According to the RACH configuration, the UE obtains the number of FDMed ROs, and RO frequency offsets with respective to PRB 0. UE may record a list, such as Table 1 or Table 4, to describe offsets between ROs and the BWP reference point, such as PRB 0 or the center of the initial UL BWP.

2. The UE MAC layer selects an SSB with SSB-RSP above rsrp-ThresholdSSB, if any, or selects an SSB randomly. The UE MAC layer determines available RACH occasion (s) from the RACH occasions corresponding to the selected SSB in the association period. The selected SSB may be associated with multiple RACH occasions:

a) If at least one of the RACH occasions associated the selected SSB is directed to Δf _RB equal to Zero, the UE MAC layer selects the RACH occasion with Δf _RB equal to Zero.

b) If none of the RACH occasions associated the selected SSB directs to Δf _RB equal to Zero, the UE MAC layer may select a RACH occasion randomly with equal probability amongst the RACH occasions.

3. The UE MAC layer may obtain Δf _RB according to Table 1 or Table 4 and a formula, such as the formula (1) . The UE MAC layer instructs the UE physical layer to transmit the Random Access Preamble using the selected RACH occasion and Δf _RB.

4. If Δf _RB ≠0, the UE performs RF retuning to adjust the center frequency of the UE by an actual UE retuning offset, and the actual UE retuning offset >= Δf while the UE lowest frequency shall not exceed the lowest frequency of the selected RO.

5. UE transmits the preamble and retunes to the original center frequency of the UE.

Separate initial UL BWP (s) :

FIG. 8 shows an example of switching between initial UL BWPs. The UE may record a PRB offset list including frequency offsets between ROs and multiple reference points of different initial UL BWP. If the RACH occasion (RO) selected by the MAC entity falls in one initial UL BWP, UE may select this initial UL BWP to perform random access. BWP switching may be performed after an initial UL BWP is selected and activated as the active initial UL BWP.

An example illustrating how to select one initial UL BWP is detailed in the following. Table 5 shows an example of the PRB offset list. The UE obtains a least UE retuning offset (Δf) to determine whether to perform BWP switching. After BWP switching, the UE transmits a preamble using the selected RO.

Table 5: Offset between RO and the reference point

The UE obtains a location of a given RO, the given RO is one RO in the set of one or more ROs. The location of the given RO is represented by a first offset value of an RO frequency offset of the given RO with respect to a frequency domain reference point of a first initial UL BWP.

and

are examples of the first offset value of an RO frequency offset of the given RO. BWP0_1 is an example of the first initial UL BWP. The frequency domain reference point of the first initial UL BWP represents the lowest frequency, a center frequency, or a first physical resource block of the first initial BWP.

The location of given RO is further represented by a second offset value of an RO frequency offset of the given RO with respect to a frequency domain reference point of a second initial UL BWP.

and

are examples of the second offset value of an RO frequency offset of the given RO. BWP0_2 is an example of the second initial UL BWP. The frequency domain reference point of the second initial UL BWP represents a lowest frequency, a center frequency, or a first physical resource block of the second initial BWP.

The UE maintains in a RO offset record the first offset value and the second offset value of the given RO to form RO offset records of ROs in the set of one or more ROs, and records in a list the RO offset records associated with the ROs in the set of one or more ROs. Table 5 is an example of the list, and each row in Table 5 is an example of the RO offset record.

The given RO may direct to a first least UE retuning offset and a second least UE retuning offset. The first least UE retuning offset associated with the given RO is a least UE retuning offset derived from the location of the given RO, a bandwidth of the given RO, and the frequency range of the UE with respect to the first initial UL BWP. The second least UE retuning offset associated with the given RO is a least UE retuning offset derived from the location of the given RO, a bandwidth of the given RO, and the frequency range of the UE with respect to the second initial UL BWP. The first least UE retuning offset may be represented by

and a second least UE retuning offset may be represented by

The UE may maintain in a RO-to-retuning-offset record a first least UE retuning offset and a second least UE retuning offset associated with a given RO, where the given RO is one of the set of one or more ROs. Thus, the UE obtains RO-to-retuning-offset records of each RO in list. The following Table 6 is an example of the list:

Table 6: UE retuning offsets of hops

Examples of

associated with ROs of

indices

0, 1, 2 are

and

respectively. Examples of

associated with ROs of

indices

0, 1, 2 are

and

respectively.

and

may be determined by a method similar to formula (1) . If

the UE deprioritizes selecting of the corresponding first initial UP BWP BWP0_1 for transmitting preamble, because the given RO is out of the UE frequency range when the BWP0_1 is the active UL BWP. If

the UE deprioritizes selecting of the corresponding second initial UP BWP BWP0_2 for transmitting preamble, because the given RO is out of the UE frequency range when the BWP0_1 is the active UL BWP.

FIG. 9 shows offsets between ROs and two initial UL BWPs. Different initial UL BWPs may share a common RACH configuration. Alternatively, different initial UL BWPs may provide different RACH configurations.

Multiple initial UL BWPs with shared RACH configuration:

In some embodiments, the first initial UL BWP and the second initial UL BWP share a common random access channel (RACH) configuration. When one of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset equal to zero, the UE may select one of the initial UL BWPs as a target BWP, and perform BWP switching to the selected BWP and activate the selected BWP as the active BWP when the selected BWP is not the active BWP.

When each of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset equal to zero, the UE may select the active BWP among the first initial UL BWP and the second initial UL BWP as a target BWP.

When each of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset equal to zero, the UE may select one of the initial UL BWPs as a target BWP according to a high level indication.

Embodiments of the disclosed method using multiple initial UL BWPs with shared RACH configuration is detailed in the following.

An embodiment using an offset list –Adaption in physical layer:

1. From system information or higher layer configuration, the UE physical layer obtains a frequency location and bandwidth and RACH configuration of two or more initial UL BWPs; The base station, such as a gNB, provides RACH configuration in only one initial UL BWP which selected as a target UL BWP and activated as the active UL BWP by UE. Alternatively, the same RACH configuration may be shared between initial UL BWPs.

According to the RACH configuration, the UE obtains the number of FDMed ROs, and RO frequency offsets with respective to PRB 0. UE may record one or more lists to describe the offsets between ROs and the BWP reference point and/or retuning offsets.

2. The UE MAC layer selects an SSB with SSB-RSP above rsrp-ThresholdSSB, if any, or selects an SSB randomly. The UE MAC layer determines available RACH occasion (s) from the RACH occasions corresponding to the selected SSB in the association period. If the selected SSB is associated with multiple RACH occasions, the UE MAC layer may select a RACH occasion randomly with equal probability amongst the RACH occasions.

3. The UE MAC layer instructs the UE physical layer to transmit a random access preamble using the selected RACH occasion.

4. According to the higher-level configuration, the UE is provided a number N of SS/PBCH block (SSB) indexes per RO and a number of contention-based preambles per SS/PBCH block index per valid RACH occasion.

The UE physical layer obtains Δf _RB. If at least two of Δf _RB, such as

and

equal to zero and one Δf _RB associated with the active initial UL BWP, the active initial UL BWP is the preferred BWP during BWP selection. Alternatively, which BWP is preferred can be determined by an indication from a higher layer. Alternatively, the UE may select one of the BWP randomly. And based on this selection, the UE determines whether to perform BWP switching.

If only one of Δf _RB equal to zero, the initial UL BWP associated with the zero Δf _RB is selected by the UE as the selected BWP. If the selected BWP is not the active BWP, the UE performs BWP switching to activate the selected BWP as the active BWP.

5. UE transmits the preamble.

6. If the base station can know which initial UL BWP is used to transmit the preamble, the base station provides an uplink grant for transmitting MSG3 PUSCH. The uplink grant specifies which PUSCH resources are inside the active initial UL BWP. Otherwise, the base station selects according to some policies or configuration to allocate PUSCH resources.

7. After receiving random access response (RAR) UL Grant, the UE determines whether to perform the initial UL BWP switching according to the granted PUSCH resources.

Furthermore, a different method may be adopted:

○ The base station provides an indication in the initial UL BWP configuration, indicating which UL BWP is preferred to allocate MSG3/MSGA PUSCH resources.

○ According to the indication, the UE determines whether to perform BWP switching after transmitting the preamble.

An embodiment using an offset list –Adaption in mac layer:

1. From system information or higher layer configuration, the UE mac layer obtains a frequency location and bandwidth and RACH configuration of two or more initial UL BWPs; The base station shall provide RACH configuration in only one initial UL BWP which selected as the active UL BWP by UE.

According to the RACH configuration, the UE obtains the number of FDMed ROs, and RO frequency offsets with respective to PRB 0. UE may record a list to describe offsets between ROs and the BWP reference point, such as PRB 0 or the center of the initial UL BWP and/or retuning offsets.

3. The UE MAC layer obtains Δf _RB. If at least two of Δf _RB unequal to zero and one Δf _RB associated with the active initial UL BWP, the active initial UL BWP is the preferred BWP. Alternatively, which BWP is preferred may be specified by an indication from a higher layer. Alternatively, the UE may select a preferred RO one randomly. And based on this selection, the UE determines whether to perform BWP switching. If only one of Δf _RB equal to zero, the initial UL BWP associated with the zero Δf _RB is the selected BWP.

4. The UE MAC layer instructs the UE physical layer to transmit the Random Access Preamble using the selected RACH occasion and the selected initial UL BWP

5. UE performs BWP switching if the selected initial UL BWP isn’t the active UL BWP. UE transmits the preamble.

6. The base station provides an uplink grant for transmitting MSG3 PUSCH. The uplink grant specifies which PUSCH resources are inside the active initial UL BWP. Otherwise, the base station selects according to some policies or configuration to allocate PUSCH resources.

7. After receiving RAR UL Grant, the UE determines whether to perform the initial UL BWP switching according to the granted PUSCH resources.

Furthermore, a different method may be adopted:

○ The base station provides an indication in the initial UL BWP configuration, indicating which UL BWP allocates MSG3/MSGA PUSCH resources.

From system information or higher layer configuration, the UE physical layer obtains a frequency location and bandwidth and RACH configuration of two or more initial UL BWPs; The base station shall provide RACH configuration in only one initial UL BWP which selected as the active UL BWP by UE.

According to the RACH configuration, the UE obtains the number of FDMed ROs, and RO frequency offsets with respective to PRB 0. UE may record a list, such as Table 7, to describe relationship between ROs and the frequency range of the UE when a first initial UL BWP or a second initial UL BWP is the active BWP.

Table 7: Relationship between RACH occasion configured by BWPs and UE frequency range

Table 8: Relationship between PRACH occasion configured by BWPs and UE frequency range

In some embodiments, the UE may maintain in one of RO-to-BWP records a relationship between the first initial UL BWP and a first RO index, the first RO index represents one RO in a first BWP-related set of one or more ROs in the first RACH configuration, and the relationship between the first initial UL BWP and a first RO index shows whether the RO represented by the first RO index is included in the first initial UL BWP. ROs with

index

0, 1, 2, 3, 4 and 5 in Table 8 is an example of the first BWP-related set of one or more ROs in the first RACH configuration.

The UE may further maintain in one of the RO-to-BWP records a relationship between the second initial UL BWP and a second RO index, the second RO index represents one RO in a second BWP-related set of one or more ROs in the second RACH configuration, and the relationship between the second initial UL BWP and a second RO index shows whether the RO represented by the second RO index is included in the second initial UL BWP. ROs with index 5, 6, and 7, in Table 8 is an example of the second BWP-related set of one or more ROs in the second RACH configuration.

An embodiment using the mapping between ROs and BWPs is detailed in the following:

An embodiment using a mapping between RO and BWP –Adaption in Physical layer:

1. The UE MAC layer selects an SSB with SSB-RSP above rsrp-ThresholdSSB, if any, or selects an SSB randomly. The UE MAC layer determines available RACH occasion (s) from the RACH occasions corresponding to the selected SSB in the association period. If the selected SSB is associated with multiple RACH occasions, the UE MAC layer may select a RACH occasion randomly with equal probability amongst the RACH occasions.

2. The UE MAC layer instructs the UE physical layer to transmit a random access preamble using the selected RACH occasion.

3. According to the higher-level configuration, the UE is provided a number N of SS/PBCH block (SSB) indexes per RO and a number of contention-based preambles per SS/PBCH block index per valid RACH occasion.

The UE physical layer searches for a BWP index of an initial UL BWP with the selected RO falling in the frequency range of the UE. If at least two BWPs are located in the searching and one is the active initial UL BWP, no BWP switching will be performed. Alternatively, which BWP is preferred can be determined by an indication from a higher layer. Alternatively, the UE may select one of the BWP randomly. And based on this selection, the UE determines whether to perform BWP switching.

If only one BWP is located, the BWP is selected by the UE as the selected BWP. If the selected BWP is not the active BWP, the UE performs BWP switching to activate the selected BWP as the active BWP.

4. UE transmits the preamble.

5. The base station provides an uplink grant for transmitting MSG3 PUSCH. The uplink grant specifies which PUSCH resources are inside the active initial UL BWP. Otherwise, the base station selects according to some policies or configuration to allocate PUSCH resources.

6. After receiving RAR UL Grant, the UE determines whether to perform the initial UL BWP switching according to the granted PUSCH resources.

Furthermore, a different method may be adopted:

An embodiment using a mapping between RO and BWP –Adaption in MAC layer:

1. From system information or higher layer configuration, the UE MAC layer obtains a frequency location and bandwidth and RACH configuration of two or more initial UL BWPs. The base station provides RACH configuration in only one initial UL BWP which is selected as the active UL BWP by UE.

According to the RACH configuration, the UE obtains the number of FDMed ROs, and RO frequency offsets with respective to PRB 0. UE may record a list, such as Table 7 or Table 8, to describe relationships between the UE frequency range and ROs configured by respective BWPs.

3. The MAC layer searches for a BWP index of an initial UL BWP with one or more ROs falling in the frequency range of the UE. If at least two BWPs are located in the searching and one is the active initial UL BWP, no BWP switching will be performed. Alternatively, which BWP is preferred can be determined by an indication from a higher layer. Alternatively, the UE may select one of the BWP randomly. And based on this selection, the UE determines whether to perform BWP switching.

4. The UE MAC layer instructs the UE physical layer to transmit the Random Access Preamble using the selected RACH occasion and the selected initial UL BWP.

7. The base station provides an uplink grant for transmitting MSG3 PUSCH. The uplink grant specifies which PUSCH resources are inside the active initial UL BWP. Otherwise, the base station selects according to some policies or configuration to allocate PUSCH resources.

Furthermore, a different method may be adopted:

Multiple UL BWPs with separate RACH configuration:

FIG. 10 shows an example of multiple UL BWPs with separate RACH configurations where one RO is within UE bandwidth. The A SSB burst comprises an SSB 0, SSB 1, SSB 2, and SSB 3. The base station provides

beams

410, 411, 412, and 413 associated with the SSB 0, SSB 1, SSB 2, and SSB 3. The SSB 0 is associated with an RO 320 and an RO 330. The SSB 1 is associated with an RO 321 and an RO 331. The SSB 2 is associated with an RO 322 and an RO 332. The SSB 3 is associated with an RO 323 and an RO 333. The ROs 320-323 are associated with the first initial UL BWP BWP0_1. The ROs 330-333 are associated with the second initial UL BWP BWP0_2. When the UE receives the beam 413, the RO 333 is in the frequency range of the UE while the RO 323 is out of the frequency range of the UE.

The UE may maintain in an RO-to-UE-frequency-range record a relationship between a given RO and the frequency range of the UE, where the given RO is one RO in the sets of one or more ROs. The relationship between the given RO and the frequency range of the UE shows whether the given RO is included in the frequency range of the UE. The given RO in the RO-to-UE-frequency-range record is associated with a given SSB, and the given SSB is one of SSBs in an SSB burst. The UE generates RO-to-UE-frequency-range records for the set of one or more ROs in a list. Table 9 and Table 10 are examples of the list of the RO-to-UE-frequency-range records:

Table 9

Table 10

In some embodiments, the first initial UL BWP and the second initial UL BWP have separated RACH configurations. Specifically, the first initial UL BWP is associated with a first RACH configuration, and the second initial UL BWP is associated with a second RACH configuration. For example, the first initial UL BWP is associated with a first RACH configuration that configures ROs 320-323, and the second initial UL BWP is associated with a second RACH configuration that configures ROs 330-333.

When one of the first RACH configuration and the second RACH configuration referred to as an inlier RACH configuration has an RO, such as RO 333, that is included in the frequency range of the UE, the UE selects the one of the first initial UL BWP and the second initial UL BWP associated with the inlier RACH configuration as a selected BWP.

The UE maintains in one of RO-to-BWP records a relationship between the first initial UL BWP and a first RO index. The first RO index represents one RO in a first BWP-related set of one or more ROs in the first RACH configuration. The relationship between the first initial UL BWP and a first RO index shows whether the RO represented by the first RO index is included in the first initial UL BWP. Table 9 is an example of a list including the RO-to-BWP records. An example of the first BWP-related set of one or more ROs includes the ROs 320-323 associated with the first initial UL BWP BWP0_1.

The UE maintains in one of the RO-to-BWP records a relationship between the second initial UL BWP and a second RO index. The second RO index represents one RO in a second BWP-related set of one or more ROs in the second RACH configuration. The relationship between the second initial UL BWP and a second RO index shows whether the RO represented by the second RO index is included in the second initial UL BWP. Table 10 is an example of a list including the RO-to-BWP records. An example of the second BWP-related set of one or more ROs includes the ROs 330-333 associated with the second initial UL BWP BWP0_2.

1. From system information or higher layer configuration, the UE mac layer obtains a frequency location and bandwidth and RACH configuration of two or more initial UL BWPs, and at least one initial UL BWP is within frequency range of the UE. The base station provides different RACH configurations for each initial UL BWP.

According to the RACH configuration, the UE obtains the number of FDMed ROs, and RO frequency offsets with respective to PRB 0. UE may record a list, such as Table 9 and Table 10, to describe a relationship of an SSB, an associated RO, an associated BWP, and an indication indicating whether the associated RO exceeds frequency range of the UE.

2. If at least one SSB with SSB-RSP above rsrp-ThresholdSSB, and at least one associated RO of the SSB is associated with a specific initial UL BWP and falls in the UE frequency range, the UE MAC layer may select the SSB, the associated RO, and the associated BWP. When no such SSB is available, the UE MAC layer selects any SSB, an RO, and an initial UL BWP associated with the SSB, where the associated RO of the SSB falls in the UE frequency range.

Furthermore, if at least two ROs in different UL BWPs are found and one is the active initial UL BWP, the active UL BWP and the associated RO are preferred, and no BWP switching will be performed. Alternatively, which BWP is preferred can be determined by an indication from a higher layer. Alternatively, the UE may select one of the BWP randomly. And based on this selection, the UE determines whether to perform BWP switching.

3. The UE MAC layer instructs the UE physical layer to transmit the Random Access Preamble using the selected RACH occasion in the selected initial UL BWP.

4. UE transmits the preamble using the selected RACH occasion.

At least one initial BWP within Redcap UE bandwidth with separated RACH configuration:

Table 11 shows an example of an information element (IE) UplinkConfigCommon or IE UplinkConfigCommonSIB for the higher level indication:

Table 11

The parameter initialUplinkBWP_forRedcap indicates the preferred BWP. The first initial UL BWP and the second initial UL BWP have separated RACH configurations. Specifically, the first initial UL BWP is associated with a first RACH configuration, and the second initial UL BWP is associated with a second RACH configuration. When one of the first initial UL BWP and the second initial UL BWP referred to as an inlier BWP is included in the frequency range of the UE, the UE selects the inlier BWP as a selected BWP. SSB may be selected based on reference symbol received power (RSRP) and one or more RO associated with the SSB. An embodiment is detailed in the following.

1. From system information or higher layer configuration, the UE obtains a frequency location and bandwidth and PRACH configuration of two or more initial UL BWPs, and at least one of the initial UL BWPs with separated PRACH configuration is within Redcap UE bandwidth. The UE selects the initial UL BWP as the active initial UL BWP.

2. If at least one SSB with SSB-RSP above rsrp-ThresholdSSB, the UE MAC layer selects an SSB with SS-RSRP above rsrp-ThresholdSSB, if any, or selects any SSB.

3. If an SSB is selected, the UE MAC layer shall select a PRACH occasion randomly with equal probability amongst the consecutive PRACH occasions corresponding to the selected SSB in the association period.

4. The UE MAC layer instructs the UE physical layer to transmit the Random Access Preamble using the selected PRACH occasion.

5. UE transmits the preamble.

With an indication for selecting initial UL BWP:

Table 12 shows another example of an information element (IE) UplinkConfigCommon or IE UplinkConfigCommonSIB for the higher level indication:

Table 12

An initial UL BWP indicated by the parameter initialUplinkBWP0-2 should be within redcap UE bandwidth, or one or more FDMed ROs of the initial UL BWP indicated by the parameter initialUplinkBWP0-2 should be restricted in Redcap UE bandwidth.

1. From system information or higher layer configuration, the UE obtains the uplink common configuration and two or more initial UL BWPs.

2. The UE selects an initial UL BWP indicated by the higher level indication as the active initial UL BWP according to the indication in the configuration. When the field of indication is absent, the UE selects initialUplinkBWP as the active initial UL BWP.

3. The UE selects one RO in the active initial UL BWP to transmit the preamble.

An embodiment of selecting SSB with qualified RO:

FIG. 11A shows an example of selecting SSB with qualified RO. With reference to FIG. 11A, a SSB burst comprises a SSB 0, SSB 1, SSB 2, and SSB 3. The base station provides

beams

420, 421, 422, and 423 associated with the SSB 0, SSB 1, SSB 2, and SSB 3. The SSB 0 is associated with an RO 340. The SSB 1 is associated with an RO 341. The SSB 2 is associated with an RO 342. The SSB 3 is associated with an RO 343.

One of the SSBs is selected by the UE based on the relationship between the frequency range of the UE and one RO in the set of one or more ROs which is selected as the selected RO. Specifically, one RO in the set of one or more ROs which is in the frequency range of the UE is selected as the selected RO, such as RO 343. When determining the selected RO falls in the frequency range of the UE, the UE selects an SSB, such as SSB 3, associated with the selected RO, such as RO 343, in the random access procedure.

FIG. 11B shows an example of selecting SSB with qualified RO. With reference to FIG. 11B, a SSB burst comprises a SSB 0, SSB 1, SSB 2, and SSB 3. The base station provides

beams

420, 421, 422, and 423 associated with the SSB 0, SSB 1, SSB 2, and SSB 3. The SSB 0 is associated with an RO 340a and an RO 340b. The SSB 1 is associated with an RO 341a and an RO 341b. The SSB 2 is associated with an RO 342a and an RO 342b. The SSB 3 is associated with an RO 343a and an RO 343b.

One of the SSBs is selected by the UE based on the relationship between the frequency range of the UE and one RO in the set of one or more ROs which is selected as the selected RO. Specifically, one RO in the set of one or more ROs which is in the frequency range of the UE is selected as the selected RO, such as RO 343b. When determining the selected RO falls in the frequency range of the UE, the UE selects an SSB, such as SSB 3, associated with the selected RO, such as RO 343b, in the random access procedure. An embodiment of the disclosed method is detailed in the following.

1. From system information or higher layer configuration, the UE MAC layer obtains a frequency location and bandwidth and RACH configuration from initial UL BWPs.

According to the RACH configuration, the UE obtains the number of FDMed ROs, and RO frequency offsets with respective to PRB 0. UE may record a list, such as Table 9 and Table 10, to describe a relationship of an SSB, an associated RO, an associated BWP, and an indication indicating whether the associated RO exceeds the frequency range of the UE.

2. If at least one SSB with SSB-RSP above rsrp-ThresholdSSB and at least one RO associated with the SSB falls in the UE frequency range, the UE MAC layer selects the SSB and the associated RO of the SSB. When no such SSB is available, the UE MAC layer selects any SSB with at least one associated RACH occasion falling in the UE frequency range.

4. UE transmits the preamble using the selected RACH occasion.

The UE may execute the following algorithm to realize the embodiment:

Table 13

Alternatively, in Algorithm 1-1, the step of s “Select an SSB and an RO associated with the SSB based on RSRP values of SSBs” may be replaced by a step of selecting randomly one RO and an SSB associated with the RO. Alternatively, the UE may execute the following algorithm to realize the embodiment:

Table 14

The Algorithm 1-2 includes selecting an SSB randomly. Alternatively, in Algorithm 1-2, the step of selecting an SSB randomly may be replaced by a step of selecting an RO of the selected SSB which is in the frequency range of the UE. Additionally, the UE may execute the following algorithm to realize the embodiment:

Table 15

The Algorithm 1-3 includes selecting an SSB randomly. Alternatively, in Algorithm 1-3, the step of selecting an SSB randomly may be replaced by a step of selecting an RO of the selected SSB which is in the frequency range of the UE.

FIG. 12A, FIG. 12B, and FIG. 12C show embodiments of the disclosed method according to the Algorithms 1-1, 1-2, and 1-3 respectively. The block 212 in FIG. 2 may further comprise blocks in one of FIG. 12A, FIG. 12B, and FIG. 12C.

With reference to FIG. 12A, the UE determines whether at least one SSB with RSRP greater than the threshold and with an RO in the frequency range of the UE (block 230) . When detecting an SSB with RSRP greater than the threshold and with an RO in the UE frequency range, the SSB and the RO are preferred, the UE selects the SSB with RSRP greater than the threshold and with the RO in the UE frequency range, and selects the RO associated with the SSB (block 232) . The threshold is a RSRP threshold.

When no SSB with RSRP greater than the threshold and with an RO in the UE frequency range is available, the UE determines whether at least one RO in the set of one or more ROs associated with an SSB is in the UE frequency range (block 234) .

When detecting at least one RO associated with an SSB in the frequency range, the UE selects the SSB and the RO associated with the SSB based on RSRP values of SSBs (block 235) . In the Algorithom 1-1, when no such a preferred SSB and an RO are available, determination of a factor in Block 235 regarding to whether an RO of an SSB is in the UE frequency range is placed after determination of a factor in block 234 regarding RSRP of an SSB during SSB selection operations.

When no RO associated with an SSB is in the frequency range, the UE selects an SSB randomly (block 236) and determines whether an SSB is selected without selecting an RO (block 237) .

When detecting an SSB selected without selecting an RO, the UE selects an RO associated with the selected SSB (block 238) .

With reference to FIG. 12B, the UE determines whether at least one SSB with RSRP greater than the threshold and with an RO in the frequency range of the UE (block 230) . When detecting an SSB with RSRP greater than the threshold and with an RO in the UE frequency range, the UE selects the SSB with RSRP greater than the threshold and with the RO in the UE frequency range, and selects the RO associated with the SSB (block 232) .

When no SSB with RSRP greater than the threshold and with an RO in the UE frequency range is available, the UE determines whether at least one SSB with RSRP greater than the threshold is available (block 234a) .

When detecting at least one SSB with RSRP greater than the threshold, the UE selects an SSB with RSRP greater than the threshold (block 235a) . In the Algorithom 1-2, when no such a preferred SSB and an RO are available, determination of a factor in

Blocks

234a and 235a regarding to RSRP of an SSB is performed following block 230 during SSB selection operations.

When no SSB with RSRP is greater than the threshold, the UE selects an SSB randomly (block 236) and determines whether an SSB is selected without selecting an RO (block 237) .

With reference to FIG. 12C, the UE determines whether at least one SSB with RSRP greater than the threshold and with an RO in the frequency range of the UE (block 230) . When detecting an SSB with RSRP greater than the threshold and with an RO in the UE frequency range, the UE selects the SSB with RSRP greater than the threshold and with the RO in the UE frequency range, and selects the RO associated with the SSB (block 232) .

When no SSB with RSRP greater than the threshold and with an RO in the UE frequency range is available, the UE selects an SSB randomly (block 236) and determines whether an SSB is selected without selecting an RO (block 237) .

Embodiments for MSG3 Scheduled by RAR UL Grant and MSGA PUSCH:

In some embodiments of the disclosure, the RACH-related resources may comprise hops in a frequency domain for transmitting a random access uplink message during a subsequent portion of the random access procedure. The random access uplink message may be a physical uplink shared channel (PUSCH) in a msg3 or a msgA-PUSCH.

Proper RF-retuning:

FIG. 13 shows PUSCH resources for 1st hop and 2nd hop. L _RB represents the bandwidth of a hop. RB _start represents the lowest frequency of a hop. RB _offset represents a location of a hop represented by a frequency domain offset with respect to a reference point of a BWP. The reference point is PRB0 of BWP. The lowest frequency in the frequency range of the UE is aligned with PRB0 of BWP.

The UE may use an algorithm in Table 16 to calculate a least UE retuning offset associated with the 1st hop. The UE may use an algorithm in Table 17 to calculate a least UE retuning offset associated with the 2nd hop. If Δf ≠0, the UE performs RF retuning. As the reference point may be different, so the formula in the algorithm can be modified accordingly.

Table 16

Table 17

For a hop of PUSCH transmission, if the frequency span of the hop is in the UE frequency range, the UE transmits the PUSCH through the hop. Otherwise, UE obtains a least UE retuning offset (Δf) to adjust UE RF center frequency. After retuning, UE transmits the PUSCH through the hop. After transmission, the UE may retune to the original center frequency.

Separate initial UL BWP (s) with the same PUSCH resources:

For a hop of PUSCH transmission, if the frequency span of the hop is in the UE frequency range, the UE transmits the PUSCH through the hop. Otherwise, assuming that the other initial UL BWP is the active UL BWP, UE determines whether the frequency span of the hop is in the UE frequency range. If so, UE selects the other initial UL BWP as the active UL BWP, and then UE performs BWP switching before the hop of PUSCH transmission.

The UE selects one hop in a set of one or more hops in a frequency domain for transmitting a random access uplink message during a subsequent portion of the random access procedure according to a relationship between the hop and the frequency range of the UE. The set of one or more hops is configured in an uplink related configuration. The random access uplink message is a physical uplink shared channel (PUSCH) in a msg3 or a msgA-PUSCH during the random access procedure, and the set of one or more hops is configured in a PUSCH configuration.

The UE may obtain a location of a given hop, the given hop is one hop in the set of one or more hops, the location of the given hop is represented by a hop frequency offset of the given hop with respect to a frequency domain reference point of an initial uplink (UL) bandwidth part (BWP) . The frequency domain reference point of the BWP represents a lowest frequency, a center frequency, or a first physical resource block of the initial UL BWP.

The UE may maintain in a hop offset record the hop frequency offset of the given hop to form hop frequency offsets of hops in the set of one or more hops, and records in a list the hop frequency offsets associated with the hops in the set of one or more hops.

The UE may maintain in a retuning offset record the UE retuning offset derived from a given hop to form UE retuning offsets of hops in the set of one or more hops, and records in a list the UE retuning offsets associated with the hops in the set of one or more hops. The given hop is one of the set of one or more hops. The following table is an example of the list.

Table 18: UE retuning offsets of hops

hop index	UE retuning Offset
0	Δf _{RB_hop0}
1	Δf _{RB_hop1}
…	…

The UE may obtain a location of a given hop. The given hop is one hop in the set of one or more hops. The location of the given hop is represented by a first offset value of a hop frequency offset of the given hop with respect to a frequency domain reference point of a first initial UL BWP. The frequency domain reference point of the first initial UL BWP represents the lowest frequency, a center frequency, or a first physical resource block of the first initial BWP.

The location of the given hop is further represented by a second offset value of a hop frequency offset of the given hop with respect to a frequency domain reference point of a second initial UL BWP. The frequency domain reference point of the second initial UL BWP represents a lowest frequency, a center frequency, or a first physical resource block of the second initial BWP.

The UE may maintain in a hop offset record the first offset value and the second offset value of the given hop to form hop offset records of hops in the set of one or more hops, and records in a list the hop offset records associated with the hops in the set of one or more hops.

The given hop may direct to a first least UE retuning offset and a second least UE retuning offset. The first least UE retuning offset associated with the given hop is a least UE retuning offset derived from the location of the given hop, a bandwidth of the given hop, and the frequency range of the UE with respect to the first initial UL BWP. The second least UE retuning offset associated with the given hop is a least UE retuning offset derived from the location of the given hop, a bandwidth of the given hop, and the frequency range of the UE with respect to the second initial UL BWP. The first least UE retuning offset may be represented by

and a second least UE retuning offset may be represented by

The UE may maintain in a hop-to-retuning-offset record a first least UE retuning offset and a second least UE retuning offset associated with a given hop, where the given hop is one of the set of one or more hops. Thus, the UE obtains hop-to-retuning-offset records of each hop in list. The following table is an example of the list.

Table 19: UE retuning offsets of hops

The first initial UL BWP and the second initial UL BWP share a common physical uplink shared channel (PUSCH) configuration.

When one of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset Δf equal to zero, The UE selects the one of the first initial UL BWP and the second initial UL BWP as a selected BWP. The UE performs BWP switching to the selected BWP when the selected BWP is not the active BWP.

When each of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset Δf equal to zero, the UE selects the active BWP among the first initial UL BWP and the second initial UL BWP as a selected BWP.

When each of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset Δf equal to zero, the UE selects one of the first initial UL BWP and the second initial UL BWP as a selected BWP according to a high level indication.

The UE may maintain in one of hop-to-BWP records a relationship between the first initial UL BWP and a first hop index. The first hop index represents one hop in a first BWP-related set of one or more hops in the first PUSCH configuration, and the relationship between the first initial UL BWP and a first hop index shows whether the hop represented by the first hop index is included in the first initial UL BWP.

The UE may maintain in one of the hop-to-BWP records a relationship between the second initial UL BWP and a second hop index. The second hop index represents one hop in a second BWP-related set of one or more hops in the second PUSCH configuration, and the relationship between the second initial UL BWP and a second hop index shows whether the hop represented by the second hop index is included in the second initial UL BWP.

The first initial UL BWP and the second initial UL BWP have separated PUSCH configurations. The first initial UL BWP is associated with a first PUSCH configuration, and the second initial UL BWP is associated with a second PUSCH configuration. When one of the first PUSCH configuration and the second PUSCH configuration referred to as an inlier PUSCH configuration has a hop that is included in the frequency range of the UE, the UE selects one of the first initial UL BWP and the second initial UL BWP associated with the inlier PUSCH configuration as a selected BWP.

The first initial UL BWP and the second initial UL BWP have separated PUSCH configurations. The first initial UL BWP is associated with a first PUSCH configuration, and the second initial UL BWP is associated with a second PUSCH configuration. When one of the first initial UL BWP and the second initial UL BWP referred to as an inlier BWP is included in the frequency range of the UE, the UE selects the inlier BWP as a selected BWP.

The UE retunes the frequency range of the UE to cover the selected hop when a frequency span of the selected hop is not included in the frequency range of the UE. One hop in the set of one or more hops which is in the frequency range of the UE is selected as the selected hop.

A physical layer entity in the UE may select the selected hop. Alternatively, a medium access control (MAC) layer entity in the UE selects the selected hop.

The UE may maintain in a hop-to-UE-frequency-range record a relationship between a given hop and the frequency range of the UE. The given hop is one hop in the sets of one or more hops, and the relationship between the given hop and the frequency range of the UE shows whether the given hop is included in the frequency range of the UE.

Different interpretation for frequency offset:

represents a size or bandwidth of a BWP in units of RB. Different interpretation for

which used in the PUSCH frequency hopping procedure and UL frequency resource allocation type 1, such as the frequency offset for the second hop given in TS Table 8.3-1 of TS 38.213 and the resource indication value formula in TS 38.214 6.1.2.2.2 , should be supported.

For the frequency domain allocation and for the formula to define the resource indication value (RIV) ,

is one of the factors. If

will be interpreted as RB number of UE frequency range

Table 18 shows an example of the formula for calculating the RIV:

Table 20

For the frequency offset of second hop PUSCH, if

will be interpreted as RB number of UE frequency range

Further an indication can be provided by the base station in a higher level indication, such as System information or RRC singling. After obtaining this indication, UE can perform the above different interpretation. FIG. 14 shows an example of applying the different interpretation for the 2nd hop frequency offset.

Embodiments for MSG4/MAGB HARQ-ACK:

In some embodiments of the disclosure, the RACH related resources may comprise hops in a frequency domain for transmitting a random access uplink message during a subsequent portion of the random access procedure. The random access uplink message may be a physical uplink control channel (PUCCH) in a msg4 HARQ-ACK or a msgB during the random access procedure. The set of one or more hops is configured in a PUCCH configuration.

Proper RF-retuning:

FIG. 15 shows an example of PUCCH RF-retuning.

The UE obtains a location of a given hop. The given hop is one hop in the set of one or more hops. The location of the given hop is represented by a hop frequency offset of the given hop with respect to a frequency domain reference point of an initial uplink (UL) bandwidth part (BWP) . The frequency domain reference point of the BWP represents a lowest frequency, a center frequency, or a first physical resource block of the initial UL BWP.

The UE maintains in a hop offset record the hop frequency offset of the given hop to form hop frequency offsets of hops in the set of one or more hops, and records in a list the hop frequency offsets associated with the hops in the set of one or more hops.

Table 21: UE retuning offsets of hops

hop index	UE retuning Offset
0	Δf _{RB_hop0}
1	Δf _{RB_hop1}
…	…

The UE obtains a location of a given hop. The given hop is one hop in the set of one or more hops. The location of the given hop is represented by a first offset value of a hop frequency offset of the given hop with respect to a frequency domain reference point of a first initial UL BWP. The frequency domain reference point of the first initial UL BWP represents a lowest frequency, a center frequency, or a first physical resource block of the first initial BWP.

The location of given hop is further represented by a second offset value of a hop frequency offset of the given hop with respect to a frequency domain reference point of a second initial UL BWP. The frequency domain reference point of the second initial UL BWP represents a lowest frequency, a center frequency, or a first physical resource block of the second initial BWP.

The UE maintains in a hop offset record the first offset value and the second offset value of the given hop to form hop offset records of hops in the set of one or more hops, and records in a list the hop offset records associated with the hops in the set of one or more hops.

and a second least UE retuning offset may be represented by

Table 22: UE retuning offsets of hops

For PUCCH format 0/1, the length in frequency domain is 1 RB, that is L _RB =1.

The UE may use algorithm in Table 19 to calculate a least UE retuning offset associated with the 1st hop. The UE may use algorithm in Table 20 to calculate a least UE retuning offset associated with the 2nd hop. If Δf ≠0, the UE performs RF retuning. As the reference point may be different, so the formula in the algorithm can be modified accordingly.

Table 23

Table 24

For a hop of PUSCH transmission, if the frequency span of the hop is in the UE frequency range, the UE transmits the PUSCH hop. Otherwise, UE obtains a least UE retuning offset (Δf) to adjust UE RF center frequency. After retuning, UE transmits the PUSCH through the hop. After transmission, the UE may retune to the original center frequency.

Separate initial UL BWP (s) :

Embodiments with the same PUCCH resources:

For a hop of PUCCH transmission, if the frequency span of the hop is in the UE frequency range, the UE transmits the PUCCH hop. Otherwise, assuming that the other initial UL BWP is the active UL BWP, UE determines whether the frequency span of the hop is in UE frequency range. If yes, the UE selects the other initial UL BWP as the active UL BWP, and performs BWP switching before the hop of PUCCH transmission.

The first initial UL BWP and the second initial UL BWP may share a common physical uplink control channel (PUCCH) configuration.

The UE maintains in one of hop-to-BWP records a relationship between the first initial UL BWP and a first hop index, the first hop index represents one hop in a first BWP-related set of one or more hops in the first PUCCH configuration. The relationship between the first initial UL BWP and a first hop index shows whether the hop represented by the first hop index is included in the first initial UL BWP.

The UE maintains in one of the hop-to-BWP records a relationship between the second initial UL BWP and a second hop index, the second hop index represents one hop in a second BWP-related set of one or more hops in the second PUCCH configuration. The relationship between the second initial UL BWP and a second hop index shows whether the hop represented by the second hop index is included in the second initial UL BWP.

At least one initial BWP within Redcap UE bandwidth is associated with separated PUCCH resources:

Table 21 shows another example of an information element (IE) UplinkConfigCommon or IE UplinkConfigCommonSIB for the higher level indication:

Table 25

1、 From system information or higher layer configuration, the UE obtains a frequency location and bandwidth and RACH configuration of two or more initial UL BWPs, and at least one of the initial UL BWPs with separated PUCCH configuration is within Redcap UE bandwidth. The UE selects the initial UL BWP as the active initial UL BWP.

2、 Before transmitting a HARQ-ACK information for MSG4/MSGB, if the active initial UL BWP isn’t within Redcap UE bandwidth, UE performs BWP switching to the initial UL BWP within redcap UE bandwidth.

3、 The UE transmits a HARQ-ACK information for MSG4/MSGB in a PUCCH transmission

The first initial UL BWP and the second initial UL BWP have separated PUCCH configurations. The first initial UL BWP is associated with a first PUCCH configuration, and the second initial UL BWP is associated with a second PUCCH configuration.

When one of the first PUCCH configuration and the second PUCCH configuration referred to as an inlier PUCCH configuration has a hop that is included in the frequency range of the UE, the UE selects one of the first initial UL BWP and the second initial UL BWP associated with the inlier PUCCH configuration as a selected BWP.

The UE maintains in one of hop-to-BWP records a relationship between the first initial UL BWP and a first hop index. The first hop index represents one hop in a first BWP-related set of one or more hops in the first PUCCH configuration, and the relationship between the first initial UL BWP and a first hop index shows whether the hop represented by the first hop index is included in the first initial UL BWP.

The UE maintains in one of the hop-to-BWP records a relationship between the second initial UL BWP and a second hop index. The second hop index represents one hop in a second BWP-related set of one or more hops in the second PUCCH configuration, and the relationship between the second initial UL BWP and a second hop index shows whether the hop represented by the second hop index is included in the second initial UL BWP.

When one of the first initial UL BWP and the second initial UL BWP referred to as an inlier BWP is included in the frequency range of the UE, the UE selects the inlier BWP as a selected BWP.

A physical layer entity in the UE selects the selected hop. A medium access control (MAC) layer entity in the UE selects the selected hop.

The UE maintains in a hop-to-UE-frequency-range record a relationship between a given hop and the frequency range of the UE. The given hop is one hop in the sets of one or more hops, and the relationship between the given hop and the frequency range of the UE shows whether the given hop is included in the frequency range of the UE.

Only one initial UL BWP with separate PUCCH configurations:

The UE may be provided two pucch-ResouceCommon parameters in system information or higher layer configuration. One of the parameters is dedicated for Redcap UEs, for example:

Table 26

If a UE is provided PUCCH common resource configuration dedicated for Redcap UEs, the UE transmits HARQ-ACK information for MSG4/MSGB in a PUCCH transmission using a PUCCH common resource dedicated for Redcap UEs

Different interpretation for the PRB index of 1st hop and 2nd hop:

The afore-mention embodiments are applicable for PUCCH frequency hopping. When UE determines the PRB index of the PUCCH transmission in the first hop and the second hop,

will be interpreted as the RB number of the current UE frequency range.

will be interpreted as the RB offset with the lowest PRB of the UE frequency range.

FIG. 16 is a block diagram of an example system 700 for wireless communication according to an embodiment of the present disclosure. Embodiments described herein may be implemented into the system using any suitably configured hardware and/or software. FIG. 16 illustrates the system 700 including a radio frequency (RF) circuitry 710, a baseband circuitry 720, a processing unit 730, a memory/storage 740, a display 750, a camera 760, a sensor 770, and an input/output (I/O) interface 780, coupled with each other as illustrated.

The processing unit 730 may include a circuitry, such as, but not limited to, one or more single-core or multi-core processors. The processors may include any combinations of general-purpose processors and dedicated processors, such as graphics processors and application processors. The processors may be coupled with the memory/storage and configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems running on the system.

The baseband circuitry 720 may include circuitry, such as, but not limited to, one or more single-core or multi-core processors. The processors may include a baseband processor. The baseband circuitry may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency shifting, etc. In some embodiments, the baseband circuitry may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry may support communication with 5G NR, LTE, an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN) , a wireless local area network (WLAN) , a wireless personal area network (WPAN) . Embodiments in which the baseband circuitry is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry. In various embodiments, the baseband circuitry 720 may include circuitry to operate with signals that are not strictly considered as being in a baseband frequency. For example, in some embodiments, baseband circuitry may include circuitry to operate with signals having an intermediate frequency, which is between a baseband frequency and a radio frequency.

The RF circuitry 710 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry may include switches, filters, amplifiers, etc. to facilitate communication with the wireless network. In various embodiments, the RF circuitry 710 may include circuitry to operate with signals that are not strictly considered as being in a radio frequency. For example, in some embodiments, RF circuitry may include circuitry to operate with signals having an intermediate frequency, which is between a baseband frequency and a radio frequency.

In various embodiments, the transmitter circuitry, control circuitry, or receiver circuitry discussed above with respect to the UE, eNB, or gNB may be embodied in whole or in part in one or more of the RF circuitries, the baseband circuitry, and/or the processing unit. As used herein, “circuitry” may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC) , an electronic circuit, a processor (shared, dedicated, or group) , and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the electronic device circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, some or all of the constituent components of the baseband circuitry, the processing unit, and/or the memory/storage may be implemented together on a system on a chip (SOC) .

The memory/storage 740 may be used to load and store data and/or instructions, for example, for the system. The memory/storage for one embodiment may include any combination of suitable volatile memory, such as dynamic random access memory (DRAM) ) , and/or non-volatile memory, such as flash memory. In various embodiments, the I/O interface 780 may include one or more user interfaces designed to enable user interaction with the system and/or peripheral component interfaces designed to enable peripheral component interaction with the system. User interfaces may include, but are not limited to a physical keyboard or keypad, a touchpad, a speaker, a microphone, etc. Peripheral component interfaces may include, but are not limited to, a non-volatile memory port, a universal serial bus (USB) port, an audio jack, and a power supply interface.

In various embodiments, the sensor 770 may include one or more sensing devices to determine environmental conditions and/or location information related to the system. In some embodiments, the sensors may include, but are not limited to, a gyro sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of, or interact with, the baseband circuitry and/or RF circuitry to communicate with components of a positioning network, e.g., a global positioning system (GPS) satellite. In various embodiments, the display 750 may include a display, such as a liquid crystal display and a touch screen display. In various embodiments, the system 700 may be a mobile computing device such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smartphone, etc. In various embodiments, system may have more or less components, and/or different architectures. Where appropriate, methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-transitory storage medium.

The embodiment of the present disclosure is a combination of techniques/processes that can be adopted in 3GPP specification to create an end product.

A person having ordinary skill in the art understands that each of the units, algorithm, and steps described and disclosed in the embodiments of the present disclosure are realized using electronic hardware or combinations of software for computers and electronic hardware. Whether the functions run in hardware or software depends on the condition of application and design requirement for a technical plan. A person having ordinary skill in the art can use different ways to realize the function for each specific application while such realizations should not go beyond the scope of the present disclosure. It is understood by a person having ordinary skill in the art that he/she can refer to the working processes of the system, device, and unit in the above-mentioned embodiment since the working processes of the above-mentioned system, device, and unit are basically the same. For easy description and simplicity, these working processes will not be detailed.

It is understood that the disclosed system, device, and method in the embodiments of the present disclosure can be realized with other ways. The above-mentioned embodiments are exemplary only. The division of the units is merely based on logical functions while other divisions exist in realization. It is possible that a plurality of units or components are combined or integrated in another system. It is also possible that some characteristics are omitted or skipped. On the other hand, the displayed or discussed mutual coupling, direct coupling, or communicative coupling operate through some ports, devices, or units whether indirectly or communicatively by ways of electrical, mechanical, or other kinds of forms.

The units as separating components for explanation are or are not physically separated. The units for display are or are not physical units, that is, located in one place or distributed on a plurality of network units. Some or all of the units are used according to the purposes of the embodiments. Moreover, each of the functional units in each of the embodiments can be integrated in one processing unit, physically independent, or integrated in one processing unit with two or more than two units.

If the software function unit is realized and used and sold as a product, it can be stored in a readable storage medium in a computer. Based on this understanding, the technical plan proposed by the present disclosure can be essentially or partially realized as the form of a software product. Or, one part of the technical plan beneficial to the conventional technology can be realized as the form of a software product. The software product in the computer is stored in a storage medium, including a plurality of commands for a computational device (such as a personal computer, a server, or a network device) to run all or some of the steps disclosed by the embodiments of the present disclosure. The storage medium includes a USB disk, a mobile hard disk, a read-only memory (ROM) , a random access memory (RAM) , a floppy disk, or other kinds of media capable of storing program codes.

The UE selects one resource from the RACH related resources for transmitting a RACH related message. The UE prioritizes RACH related resources based on UE retuning offsets associated with the RACH related resources during the selecting of RACH related resources such that an resource of the RACH related resources with a less UE retuning offset is prioritized over another resource of the RACH related resources with a greater UE retuning offset in the selecting of RACH related resources. The invention provides embodiments with various options, such as proper RF-retuning and separate initial UL BWP (s) . These specific methods enable UE bandwidth to include a frequency range of a PRACH occasion associated with the best SSB, a frequency range of PUCCH for Msg4/MsgB HARQ feedback, and/or a frequency range of PUSCH for Msg3/MsgA during initial access.

While the present disclosure has been described in connection with what is considered the most practical and preferred embodiments, it is understood that the present disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Claims

A random access processing method executable in a user equipment (UE) , comprising:

receiving and identifying random access channel (RACH) related configuration to obtain RACH related resources; and

selecting one resource from the RACH related resources for transmitting a RACH related message, wherein selection of the RACH related resources is prioritized based on whether a RACH related transition operation is required following selection of one resource such that a resource in the RACH related resources not requiring a RACH related transition operation is prioritized over another resource in the RACH related resources requiring a RACH related transition operation in the selecting of the RACH related resources.
The random access processing method of claim 1, wherein RACH related resources comprise a set of one or more random access channel occasions (ROs) , and the method further comprises:

selecting a synchronization signal block (SSB) associated with a subset in the set of one or more ROs for transmitting the RACH related message in a random access procedure;

determining whether to retune a frequency range of the UE or not based on a relationship between the frequency range of the UE and one RO selected from the set of the one or more ROs; and

transmitting the RACH related message through the selected RO.
The random access processing method of claim 2, wherein the UE obtains a location of a given RO, the given RO is one RO in the set of one or more ROs, the location of the given RO is represented by an RO frequency offset of the given RO with respect to a frequency domain reference point of an initial uplink (UL) bandwidth part (BWP) , the frequency domain reference point of the BWP represents a lowest frequency, a center frequency, or a first physical resource block of the initial UL BWP.
The random access processing method of claim 3, wherein the UE maintains in an RO offset record the RO frequency offset of the given RO to form RO frequency offsets of ROs in the set of one or more ROs, and records in a list the RO frequency offsets associated with the ROs in the set of one or more ROs.
The random access processing method of claim 2, wherein the UE obtains a location of a given RO, the given RO is one RO in the set of one or more ROs, the location of the given RO is represented by a first offset value of an RO frequency offset of the given RO with respect to a frequency domain reference point of a first initial UL BWP, the frequency domain reference point of the first initial UL BWP represents a lowest frequency, a center frequency, or a first physical resource block of the first initial BWP; and

the location of given RO is further represented by a second offset value of an RO frequency offset of the given RO with respect to a frequency domain reference point of a second initial UL BWP, the frequency domain reference point of the second initial UL BWP represents a lowest frequency, a center frequency, or a first physical resource block of the second initial BWP.
The random access processing method of claim 5, wherein the UE maintains in a RO offset record the first offset value and the second offset value of the given RO to form RO offset records of ROs in the set of one or more ROs, and records in a list the RO offset records associated with the ROs in the set of one or more ROs.
The random access processing method of claim 5, wherein the UE may maintain in a retuning offset record the UE retuning offset derived from the given RO to form UE retuning offsets of ROs in the set of one or more ROs, and records in a list the UE retuning offsets associated with the ROs in the set of one or more ROs.
The random access processing method of claim 5, wherein the first initial UL BWP and the second initial UL BWP share a common random access channel (RACH) configuration.
The random access processing method of claim 8, wherein when one of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset equal to zero, the UE selects the one of the first initial UL BWP and the second initial UL BWP as a selected BWP; and

performing BWP switching to the selected BWP when the selected BWP is not the active BWP.
The random access processing method of claim 8, wherein when each of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset equal to zero, the UE selects the active BWP among the first initial UL BWP and the second initial UL BWP as a selected BWP.
The random access processing method of claim 8, wherein when each of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset equal to zero, the UE selects one of the first initial UL BWP and the second initial UL BWP as a selected BWP according to a high level indication.
The random access processing method of claim 8, wherein the UE maintains in one of RO-to-BWP records a relationship between the first initial UL BWP and a first RO index, the first RO index represents one RO in a first BWP-related set of one or more ROs in the first RACH configuration, and the relationship between the first initial UL BWP and a first RO index shows whether the RO represented by the first RO index is included in the first initial UL BWP;

the UE maintains in one of the RO-to-BWP records a relationship between the second initial UL BWP and a second RO index, the second RO index represents one RO in a second BWP-related set of one or more ROs in the second RACH configuration, and the relationship between the second initial UL BWP and a second RO index shows whether the RO represented by the second RO index is included in the second initial UL BWP.
The random access processing method of claim 8, wherein a given RO directs to a first least UE retuning offset and a second least UE retuning offset, the first least UE retuning offset associated with the given RO is a least UE retuning offset derived from the location of the given RO, a bandwidth of the given RO, and the frequency range of the UE with respect to the first initial UL BWP, the second least UE retuning offset associated with the given RO is a least UE retuning offset derived from the location of the given RO, a bandwidth of the given RO, and the frequency range of the UE with respect to the second initial UL BWP, the UE may maintain in a RO-to-retuning-offset record the first least UE retuning offset and the second least UE retuning offset associated with the given RO, and the given RO is one of the set of one or more ROs.
The random access processing method of claim 5, wherein the first initial UL BWP and the second initial UL BWP have separated RACH configurations, the first initial UL BWP is associated with a first RACH configuration, and the second initial UL BWP is associated with a second RACH configuration;

wherein when one of the first RACH configuration and the second RACH configuration referred to as an inlier RACH configuration has an RO that is included in the frequency range of the UE, the UE selects one of the first initial UL BWP and the second initial UL BWP associated with the inlier RACH configuration as a selected BWP.
The random access processing method of claim 14, wherein the UE maintains in one of RO-to-BWP records a relationship between the first initial UL BWP and a first RO index, the first RO index represents one RO in a first BWP-related set of one or more ROs in the first RACH configuration, and the relationship between the first initial UL BWP and a first RO index shows whether the RO represented by the first RO index is included in the first initial UL BWP;

the UE maintains in one of the RO-to-BWP records a relationship between the second initial UL BWP and a second RO index, the second RO index represents one RO in a second BWP-related set of one or more ROs in the second RACH configuration, and the relationship between the second initial UL BWP and a second RO index shows whether the RO represented by the second RO index is included in the second initial UL BWP.
The random access processing method of claim 5, wherein the first initial UL BWP and the second initial UL BWP have separated RACH configurations, the first initial UL BWP is associated with a first RACH configuration, and the second initial UL BWP is associated with a second RACH configuration;

wherein when one of the first initial UL BWP and the second initial UL BWP referred to as an inlier BWP is included in the frequency range of the UE, the UE selects the inlier BWP as a selected BWP.
The random access processing method of claim 1, wherein RACH related resources comprise a set of one or more random access channel occasions (ROs) , and the method further comprises:

selecting a synchronization signal block (SSB) associated with a subset in the set of one or more ROs for transmitting the RACH related message in a random access procedure; and

transmitting the RACH related message through the selected RO.
The random access processing method of claim 17, further comprising:

determining whether to retune a frequency range of the UE or not based on a relationship between the frequency range of the UE and one RO selected from the set of the one or more ROs; and

retuning the frequency range of the UE to cover the selected RO when a frequency span of the selected RO is not included in the frequency range of the UE.
The random access processing method of claim 17, wherein the SSB is selected based on the relationship between the frequency range of the UE and one RO selected from the set of one or more ROs.
The random access processing method of claim 19, further comprising:

determining whether an SSB is is a preferred SSB associated with a reference signal receiving power (RSRP) greater than a receiving power threshold and with an RO in the frequency range of the UE; and

selecting the preferred SSB in the SSB selecting.
The random access processing method of claim 20, further comprising:

determining whether at least one RO in the set of one or more ROs associated with an SSB is in the frequency range of the UE when no such preferred SSB is available;

selecting one RO in the set of one or more ROs which is in the frequency range of the UE as the selected RO; and

selecting an SSB from a plurality of SSBs, which is associated with the selected RO based on RSRP values of the SSBs in the SSB selecting.
The random access processing method of claim 20, further comprising:

determining whether at least one SSB with RSRP greater than the threshold is available when no such preferred SSB is available; and

selecting an SSB with RSRP greater than the threshold in the SSB selecting.
The random access processing method of claim 20, wherein a physical layer entity in the UE selects the selected RO.
The random access processing method of claim 20, wherein a medium access control (MAC) layer entity in the UE selects the selected RO.
The random access processing method of claim 20, wherein the UE maintains in an RO-to-UE-frequency-range record a relationship between a given RO and the frequency range of the UE, the given RO is one RO in the sets of one or more ROs, and the relationship between the given RO and the frequency range of the UE shows whether the given RO is included in the frequency range of the UE.
The random access processing method of claim 25, wherein the given RO in the RO-to-UE-frequency-range record is associated with a given SSB, and the given SSB is one of SSBs in an SSB burst.
The random access processing method of one of claims 17, 18, 19, and 20, further comprising:

obtaining a least UE retuning offset Δf _RB associated with each RO in the set of one or more ROs from the location of the RO, a bandwidth of the RO, and the frequency range of the UE; and

determining the relationship between the frequency range of the UE and the selected RO using the least UE retuning offset.
The random access processing method of claim 27, wherein when a RO frequency offset RB _offset of a lowest frequency of a specific RO in the set of one or more ROs is measured with respect to a lowest frequency of an initial UL BWP, the least UE retuning offset Δf _RB of the UE associated with the specific RO is calculated using a RO frequency offset RB _offset of a specific RO, a bandwidth RB _prach of a specific RO, and a bandwidth
of the frequency range of the UE according to:

if
The random access processing method of claim 27, wherein when a RO frequency offset RB _offset of a lowest frequency of a specific RO in the set of one or more ROs is measured with respect to a center frequency of an initial UL BWP, the least UE retuning offset Δf _RB of the UE associated with the specific RO is calculated using a RO frequency offset RB _offset of a specific RO, a bandwidth RB _prach of a specific RO, and a bandwidth
of the frequency range of the UE according to:

if (RB _offset) < 0 and

Δf _RB = 0 if (RB _offset) < 0 and

if (RB _offset) ≥ 0 and
and

Δf _RB = 0 if (RB _offset) ≥ 0 and
The random access processing method of claim 27, wherein the RACH related message is a random access preamble.
A chip, comprising:

a processor configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute any of the methods of claims 1 to 30.
A computer readable storage medium, in which a computer program is stored, wherein the computer program causes a computer to execute any of the methods of claims 1 to 30.
A computer program product, comprising a computer program, wherein the computer program causes a computer to execute any of the methods of claims 1 to 30.
A computer program, wherein the computer program causes a computer to execute any of the methods of claims 1 to 30.
A user equipment (UE) , comprising:

a processor configured to execute:

receiving and identifying random access channel (RACH) related configuration to obtain RACH related resources; and

selecting one resource from the RACH related resources for transmitting a RACH related message, wherein selection of the RACH related resources is prioritized based on whether a RACH related transition operation is required following selection of one resource such that a resource in the RACH related resources not requiring a RACH related transition operation is prioritized over another resource in the RACH related resources requiring a RACH related transition operation in the selecting of the RACH related resources.
The user equipment of claim 35, wherein RACH related resources comprise a set of one or more random access channel occasions (ROs) , and the processor is further configured to execute:

selecting a synchronization signal block (SSB) associated with a subset in the set of one or more ROs for transmitting the RACH related message in a random access procedure;

determining whether to retune a frequency range of the UE or not based on a relationship between the frequency range of the UE and one RO selected from the set of the one or more ROs; and

transmitting the RACH related message through the selected RO.
The user equipment of claim 36, wherein the UE obtains a location of a given RO, the given RO is one RO in the set of one or more ROs, the location of the given RO is represented by an RO frequency offset of the given RO with respect to a frequency domain reference point of an initial uplink (UL) bandwidth part (BWP) , the frequency domain reference point of the BWP represents a lowest frequency, a center frequency, or a first physical resource block of the initial UL BWP.
The user equipment of claim 37, wherein the UE maintains in an RO offset record the RO frequency offset of the given RO to form RO frequency offsets of ROs in the set of one or more ROs, and records in a list the RO frequency offsets associated with the ROs in the set of one or more ROs.
The user equipment of claim 36, wherein the UE obtains a location of a given RO, the given RO is one RO in the set of one or more ROs, the location of the given RO is represented by a first offset value of an RO frequency offset of the given RO with respect to a frequency domain reference point of a first initial UL BWP, the frequency domain reference point of the first initial UL BWP represents a lowest frequency, a center frequency, or a first physical resource block of the first initial BWP; and

the location of given RO is further represented by a second offset value of an RO frequency offset of the given RO with respect to a frequency domain reference point of a second initial UL BWP, the frequency domain reference point of the second initial UL BWP represents a lowest frequency, a center frequency, or a first physical resource block of the second initial BWP.
The user equipment of claim 39, wherein the UE maintains in a RO offset record the first offset value and the second offset value of the given RO to form RO offset records of ROs in the set of one or more ROs, and records in a list the RO offset records associated with the ROs in the set of one or more ROs.
The user equipment of claim 39, wherein the UE may maintain in a retuning offset record the UE retuning offset derived from the given RO to form UE retuning offsets of ROs in the set of one or more ROs, and records in a list the UE retuning offsets associated with the ROs in the set of one or more ROs.
The user equipment of claim 39, wherein the first initial UL BWP and the second initial UL BWP share a common random access channel (RACH) configuration.
The user equipment of claim 42, wherein when one of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset equal to zero, the UE selects the one of the first initial UL BWP and the second initial UL BWP as a selected BWP; and

performing BWP switching to the selected BWP when the selected BWP is not the active BWP.
The user equipment of claim 42, wherein when each of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset equal to zero, the UE selects the active BWP among the first initial UL BWP and the second initial UL BWP as a selected BWP.
The user equipment of claim 42, wherein when each of the first initial UL BWP and the second initial UL BWP is associated with a least UE retuning offset equal to zero, the UE selects one of the first initial UL BWP and the second initial UL BWP as a selected BWP according to a high level indication.
The user equipment of claim 42, wherein the UE maintains in one of RO-to-BWP records a relationship between the first initial UL BWP and a first RO index, the first RO index represents one RO in a first BWP-related set of one or more ROs in the first RACH configuration, and the relationship between the first initial UL BWP and a first RO index shows whether the RO represented by the first RO index is included in the first initial UL BWP;

the UE maintains in one of the RO-to-BWP records a relationship between the second initial UL BWP and a second RO index, the second RO index represents one RO in a second BWP-related set of one or more ROs in the second RACH configuration, and the relationship between the second initial UL BWP and a second RO index shows whether the RO represented by the second RO index is included in the second initial UL BWP.
The user equipment of claim 42, wherein a given RO directs to a first least UE retuning offset and a second least UE retuning offset, the first least UE retuning offset associated with the given RO is a least UE retuning offset derived from the location of the given RO, a bandwidth of the given RO, and the frequency range of the UE with respect to the first initial UL BWP, the second least UE retuning offset associated with the given RO is a least UE retuning offset derived from the location of the given RO, a bandwidth of the given RO, and the frequency range of the UE with respect to the second initial UL BWP, the UE may maintain in a RO-to-retuning-offset record the first least UE retuning offset and the second least UE retuning offset associated with the given RO, and the given RO is one of the set of one or more ROs.
The user equipment of claim 39, wherein the first initial UL BWP and the second initial UL BWP have separated RACH configurations, the first initial UL BWP is associated with a first RACH configuration, and the second initial UL BWP is associated with a second RACH configuration;

wherein when one of the first RACH configuration and the second RACH configuration referred to as an inlier RACH configuration has an RO that is included in the frequency range of the UE, the UE selects one of the first initial UL BWP and the second initial UL BWP associated with the inlier RACH configuration as a selected BWP.
The user equipment of claim 48, wherein the UE maintains in one of RO-to-BWP records a relationship between the first initial UL BWP and a first RO index, the first RO index represents one RO in a first BWP-related set of one or more ROs in the first RACH configuration, and the relationship between the first initial UL BWP and a first RO index shows whether the RO represented by the first RO index is included in the first initial UL BWP;

the UE maintains in one of the RO-to-BWP records a relationship between the second initial UL BWP and a second RO index, the second RO index represents one RO in a second BWP-related set of one or more ROs in the second RACH configuration, and the relationship between the second initial UL BWP and a second RO index shows whether the RO represented by the second RO index is included in the second initial UL BWP.
The user equipment of claim 39, wherein the first initial UL BWP and the second initial UL BWP have separated RACH configurations, the first initial UL BWP is associated with a first RACH configuration, and the second initial UL BWP is associated with a second RACH configuration;

wherein when one of the first initial UL BWP and the second initial UL BWP referred to as an inlier BWP is included in the frequency range of the UE, the UE selects the inlier BWP as a selected BWP.
The user equipment of claim 35, wherein RACH related resources comprise a set of one or more random access channel occasions (ROs) , and the processor is further configured to execute:

selecting a synchronization signal block (SSB) associated with a subset in the set of one or more ROs for transmitting the RACH related message in a random access procedure; and

transmitting the RACH related message through the selected RO.
The user equipment of claim 51, wherein the processor is further configured to execute:

determining whether to retune a frequency range of the UE or not based on a relationship between the frequency range of the UE and one RO selected from the set of the one or more ROs; and

retuning the frequency range of the UE to cover the selected RO when a frequency span of the selected RO is not included in the frequency range of the UE.
The user equipment of claim 51, wherein the SSB is selected based on the relationship between the frequency range of the UE and one RO selected from the set of one or more ROs.
The user equipment of claim 53, wherein the processor is further configured to execute:

determining whether an SSB is is a preferred SSB associated with a reference signal receiving power (RSRP) greater than a receiving power threshold and with an RO in the frequency range of the UE; and

selecting the preferred SSB in the SSB selecting.
The user equipment of claim 54, wherein the processor is further configured to execute:

determining whether at least one RO in the set of one or more ROs associated with an SSB is in the frequency range of the UE when no such preferred SSB is available;

selecting one RO in the set of one or more ROs which is in the frequency range of the UE as the selected RO; and

selecting an SSB from a plurality of SSBs, which is associated with the selected RO based on RSRP values of the SSBs in the SSB selecting.
The user equipment of claim 54, wherein the processor is further configured to execute:

determining whether at least one SSB with RSRP greater than the threshold is available when no such preferred SSB is available; and

selecting an SSB with RSRP greater than the threshold in the SSB selecting.
The user equipment of claim 54, wherein a physical layer entity in the UE selects the selected RO.
The user equipment of claim 54, wherein a medium access control (MAC) layer entity in the UE selects the selected RO.
The user equipment of claim 54, wherein the UE maintains in an RO-to-UE-frequency-range record a relationship between a given RO and the frequency range of the UE, the given RO is one RO in the sets of one or more ROs, and the relationship between the given RO and the frequency range of the UE shows whether the given RO is included in the frequency range of the UE.
The user equipment of claim 59, wherein the given RO in the RO-to-UE-frequency-range record is associated with a given SSB, and the given SSB is one of SSBs in an SSB burst.
The random access processing method of one of claims 51, 52, 53, and 54, wherein the processor is further configured to execute:

obtaining a least UE retuning offset Δf _RB associated with each RO in the set of one or more ROs from the location of the RO, a bandwidth of the RO, and the frequency range of the UE; and

determining the relationship between the frequency range of the UE and the selected RO using the least UE retuning offset.
The user equipment of claim 61, wherein when a RO frequency offset RB _offset of a lowest frequency of a specific RO in the set of one or more ROs is measured with respect to a lowest frequency of an initial UL BWP, the least UE retuning offset Δf _RB of the UE associated with the specific RO is calculated using a RO frequency offset RB _offset of a specific RO, a bandwidth RB _prach of a specific RO, and a bandwidth
of the frequency range of the UE according to:

if
The user equipment of claim 61, wherein when a RO frequency offset RB _offset of a lowest frequency of a specific RO in the set of one or more ROs is measured with respect to a center frequency of an initial UL BWP, the least UE retuning offset Δf _RB of the UE associated with the specific RO is calculated using a RO frequency offset RB _offset of a specific RO, a bandwidth RB _prach of a specific RO, and a bandwidth
of the frequency range of the UE according to:

if (RB _offset) < 0 and

Δf _RB = 0 if (RB _offset) < 0 and

if (RB _offset) ≥ 0 and
and

Δf _RB = 0 if (RB _offset) ≥ 0 and
The user equipment of claim 61, wherein the RACH related message is a random access preamble.