SSB-to-RO mapping

Abstract

A terminal device 120 receives multiple random access channel (RACH) configurations, a first RACH configuration relates to a first mapping of synchronization signal blocks (SSBs) to first RACH occasio

Description

FIELD

[0001] Various example embodiments relate to the field of communication, and in particular, to devices, methods, apparatuses, and a computer readable medium for synchronization signal block (SSB) to random access channel (RACH) occasion (RO) mapping. BACKGROUND

[0002] A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network.

[0003] Such communication networks operate in accordance with standards, such as those promulgated by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of such standards include the so-called 5G (5th Generation) standard or other standards promulgated by 3GPP. SUMMARY

[0004] In general, example embodiments of the present disclosure provide a solution for synchronization signal block (SSB) to random access channel (RACH) occasion (RO) mapping (SSB-to-RO mapping), especially for SSB-to-RO mapping in sub-band nonoverlapping full duplex (SBFD).

[0005] In a first aspect, there is provided a terminal device. The terminal device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: receive a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; determine a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; determine, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO; and determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[0006] In a second aspect, there is provided a network device. The network device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: transmit, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and receive, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0007] In a third aspect, there is provided a method. The method comprises: receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; determining, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO; and determining, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[0008] In a fourth aspect, there is provided a method. The method comprises: transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACK configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and receiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0009] In a fifth aspect, there is provided an apparatus. The apparatus comprises: means for receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; means for determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; means for determining, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO; and means for determining, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[0010] In a sixth aspect, there is provided an apparatus. The apparatus comprises: means for transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and means for receiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0011] In a seventh aspect, there is provided a computer readable medium comprising program instructions for causing an apparatus to perform at least method of the above third aspect or fourth aspect.

[0012] In an eighth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus to perform at least the method of the above third aspect or fourth aspect.

[0013] In a ninth aspect, there is provided a terminal device. The terminal device comprises: receiving circuitry configured to receive a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; first determining circuitry configured to determine a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; second determining circuitry configured to determine, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO; and third determining circuitry configured to determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[0014] In a tenth aspect, there is provided a network device. The network device comprises: transmitting circuitry configured to transmit, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and receiving circuitry configured to receive, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0015] In an eleventh aspect, there is provided a terminal device. The terminal device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: receive a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; determine a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; and determine, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO.

[0016] In a twelfth aspect, there is provided a network device. The network device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: transmit, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and receive, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0017] In a thirteenth aspect, there is provided a method. The method comprises: receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; determining, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO.

[0018] In a fourteenth aspect, there is provided a method. The method comprises: transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and receiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0019] In a fifteenth aspect, there is provided an apparatus. The apparatus comprises: means for receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; means for determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; and means for determining, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO.

[0020] In a sixteenth aspect, there is provided an apparatus. The apparatus comprises: means for transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and means for receiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0021] In a seventeenth aspect, there is provided a computer readable medium comprising program instructions for causing an apparatus to perform at least method of the above thirteenth aspect or fourteenth aspect.

[0022] In an eighteenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus to perform at least the method of the above thirteenth aspect or fourteenth aspect.

[0023] In a nineteenth aspect, there is provided a terminal device. The terminal device comprises: receiving circuitry configured to receive a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; first determining circuitry configured to determine a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; and second determining circuitry configured to determine, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO.

[0024] In a twenty aspect, there is provided a network device. The network device comprises: transmitting circuitry configured to transmit, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and receiving circuitry configured to receive, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0025] In a twenty-first aspect, there is provided a terminal device. The terminal device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: receive a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; determine a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; determine, for the first set of ROs, at least one second SSB index for the second mapping; and determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[0026] In a twenty-second aspect, there is provided a network device. The network device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: transmit, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and receive, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0027] In a twenty-third aspect, there is provided a method. The method comprises: receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; determining, for the first set of ROs, at least one second SSB index for the second mapping; and determining, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[0028] In a twenty-fourth aspect, there is provided a method. The method comprises: transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and receiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0029] In a twenty-fifth aspect, there is provided an apparatus. The apparatus comprises: means for receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; means for determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; means for determining, for the first set of ROs, at least one second SSB index for the second mapping; and means for determining, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[0030] In a twenty-sixth aspect, there is provided an apparatus. The apparatus comprises: means for transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and means for receiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0031] In a twenty-seventh aspect, there is provided a computer readable medium comprising program instructions for causing an apparatus to perform at least method of the above twenty-third aspect or twenty-fourth aspect.

[0032] In a twenty-eighth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus to perform at least the method of the above twenty-third aspect or twenty-fourth aspect.

[0033] In a twenty-ninth aspect, there is provided a terminal device. The terminal device comprises: receiving circuitry configured to receive a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; first determining circuitry configured to determine a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; second determining circuitry configured to determine, for the first set of ROs, at least one second SSB index for the second mapping; and third determining circuitry configured to determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[0034] In a thirtieth aspect, there is provided a network device. The network device comprises: transmitting circuitry configured to transmit, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and receiving circuitry configured to receive, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[0035] It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0037] FIG. 1A illustrates an example of 4-step RACH procedure;

[0038] FIG. IB illustrates an example of SSB to RO mapping with normal (for example, legacy) RO validation rules and UL / DL configuration DDDSU;

[0039] FIG. IC illustrates an example of SBFD and non-SBFD slots;

[0040] FIG. 2A illustrates an example of PRACH configuration Option 1 for RA in SBFD symbols;

[0041] FIG. 2B illustrates an example of PRACH configuration Option 2-1 for RA in SBFD symbols;

[0042] FIG. 2C illustrates an example of PRACH configuration Option 2-1 with SBFD LL-ROs configured by the second RACH configuration;

[0043] FIG. 2D illustrates an example of PRACH configuration Option 2-2 for RA in SBFD symbols;

[0044] FIG. 3A illustrates an example of mapping SSBs to all SBFD LL-ROs configured by the second configuration for Option 2-1;

[0045] FIG. 3B illustrates an example of mapping SSBs to all ROs configured by the second configuration for Option 2-2;

[0046] FIG. 3C illustrates an example of mapping SSBs separately to SBFD ROs and UL ROs configured by the second configuration for Option 2-2;

[0047] FIG. 4 illustrates an example of a process flow in accordance with some example embodiments of the present disclosure;

[0048] FIG. 5 illustrates another example of a process flow in accordance with some example embodiments of the present disclosure;

[0049] FIG. 6 illustrates a further example of a process flow in accordance with some example embodiments of the present disclosure;

[0050] FIG. 7 illustrates an example message sequence flowchart for the second case in accordance with some example embodiments of the present disclosure;

[0051] FIG. 8A illustrates an example of SSB-to-RO mapping with continuous mapping in accordance with some example embodiments of the present disclosure;

[0052] FIG. 8B illustrates an example of SSB-to-RO mapping with separate mapping in accordance with some example embodiments of the present disclosure;

[0053] FIG. 8C illustrates an example of SSB-to-RO mapping in the case that msgl-FDM-1 is greater than msgl-FDM-2 in accordance with some example embodiments of the present disclosure;

[0054] FIG. 9A illustrates an example of SSB-to-RO mapping with RO sets in accordance with some example embodiments of the present disclosure;

[0055] FIG. 9B illustrates another example of SSB-to-RO mapping with RO sets in accordance with some example embodiments of the present disclosure;

[0056] FIG. 10 illustrates an example message sequence flowchart for the first case in accordance with some example embodiments of the present disclosure;

[0057] FIG. 11A illustrates an example of SSB-to-RO mapping for SBFD LL-ROs in the case that msgl-FDM-1 is equal to msgl-FDM-2 in accordance with some example embodiments of the present disclosure;

[0058] FIG. 1 IB illustrates an example of SSB-to-RO mapping for SBFD LL-ROs in the case that msgl-FDM-1 is greater than msgl-FDM-2 in accordance with some example embodiments of the present disclosure;

[0059] FIG. 1 IC illustrates an example of SSB-to-RO mapping for SBFD LL-ROs in the case that msgl-FDM-1 is less than msgl-FDM-2 in accordance with some example embodiments of the present disclosure;

[0060] FIG. 1 ID illustrates an another example of SSB-to-RO mapping for SBFD LL-ROs in the case that msgl-FDM-1 is less than msgl-FDM-2 in accordance with some example embodiments of the present disclosure;

[0061] FIG. 12 illustrates a flowchart of an example method implemented at a terminal device in accordance with some other embodiments of the present disclosure;

[0062] FIG. 13 illustrates a flowchart of an example method implemented at a network device in accordance with some other embodiments of the present disclosure;

[0063] FIG. 14 illustrates a flowchart of another example method implemented at a terminal device in accordance with some other embodiments of the present disclosure;

[0064] FIG. 15 illustrates a flowchart of another example method implemented at a network device in accordance with some other embodiments of the present disclosure;

[0065] FIG. 16 illustrates a flowchart of a further example method implemented at a terminal device in accordance with some other embodiments of the present disclosure;

[0066] FIG. 17 illustrates a flowchart of a further example method implemented at a network device in accordance with some other embodiments of the present disclosure;

[0067] FIG. 18 illustrates a simplified block diagram of a device that is suitable for implementing some example embodiments of the present disclosure; and

[0068] FIG. 19 illustrates a block diagram of an example of a computer-readable medium in accordance with some example embodiments of the present disclosure.

[0069] Throughout the drawings, the same or similar reference numerals represent the same or similar elements. DETAILED DESCRIPTION

[0070] Principles of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

[0071] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0072] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0073] It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0074] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0075] As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (for example, firmware) for operation, but the software may not be present when it is not needed for operation.

[0076] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0077] As used herein, the term “network”, “communication network” or “data network” refers to a network following any suitable communication standards, such as long term evolution (LTE), LTE-advanced (LTE-A), wideband code division multiple access (WCDMA), high-speed packet access (HSPA), narrow band Internet of things (NB-IoT), wireless fidelity (Wi-Fi) and so on. Furthermore, the communications between a terminal device and a network device / element in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the fourth generation (4G), 4.5G, the future fifth generation (5G), IEEE 802.11 communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0078] As used herein, the term “network device” refers to a node in a communication network via which a terminal device receives services (e.g., positioning services) therefrom. The network device may refer to a core network device or access network device, such as base station (BS) or an access point (AP) or a transmission and reception point (TRP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR NB (also referred to as a gNB), a remote radio unit (RRU), a radio header (RH), a remote radio head (RRH), a WiFi device, a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. In the following description, the terms “network device”, “AP device”, “AP” and “access point” may be used interchangeably.

[0079] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), a station (STA) or station device, or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (for example, remote surgery), an industrial device and applications (for example, a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. In the following description, the terms “station”, “station device”, “STA”, “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0080] Principles and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Communications in the communication system may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G) and the fifth generation (5G) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0081] Generally, in 5GNR, two contention based random access (CBRA) procedures are supported, namely 4-step RACH (Rel-15) and 2-step RACH (Rel-16) and one contention-free random-access procedure (CFRA). A step in all these procedures is the transmission of a suitable message by the UE to the network (NW) (the nature of the message changes depends on which procedure is executed, but the first action is always for the UE). In this disclosure, it may focus on the 4-step RACH procedure, given its larger relevance in practical deployments, and for its better suitability for illustration purpose and simplicity. However, the proposed concept is equally applicable to all three procedures.

[0082] FIG. 1A illustrates an example of 4-step RACH procedure. As illustrated in FIG. 1 A, the 4-step RACH procedure may be summarized as follows.

[0083] For Msgl (a.k.a. PRACH), the UE may send a specific preamble to the gNB via physical random-access channel (PRACH) using a specific resource called RACH occasion (RO), mapped to one or more SSB beams according to a certain pattern. For Msg2 (a.k.a. RAR), the gNB may reply with a random-access response (RAR) message, which includes the detected preamble ID, the time-advance command, a temporary cell radio network temporary identifier (TC-RNTI), and uplink (UL) grant for the transmission of Msg3 on PUSCH. For msg3 (a.k.a. radio resource control (RRC) request), the UE may respond to Msg2 over the scheduled PUSCH with an ID for contention resolution. And for Msg4 (a.k.a. RRC setup), the gNB may transmit the contention resolution message with the contentionresolution ID.

[0084] Upon reception of Msg4, the UE may send an ACK on a PUCCH if its contentionresolution ID is carried by Msg4. This completes the 4-step RACH. It is worth noting that prior to Msgl, there is also a preliminary step of sending and receiving the synchronization signal block (SSB), i.e., downlink (DL) beam sweeping, which is not a formal part of the RACH procedure. As a result of this preliminary step, the UE may select the index of the preferred SSB beam and decode the associated PBCH for MIB, the system information block (SIB), and so on. This index is also used by the UE to identify a suitable RO for the preamble transmission (i.e., Msgl), according to the SSB-to-RO mapping conveyed by SIB1.

[0085] It should be noted that, 2 step RACH is similar to 4 step RACH presented above, but Msgl and Msg3 are combined in a MsgA and sent out without waiting for feedback from the UE in between (traditionally Msg2). Similarly, the gNB combines Msg2 and Msg4 into MsgB. It is straightforward to apply the solutions disclosed in this disclosure for Msgl, to the preamble / Msgl part of MsgA.

[0086] In this disclosure, a RO in UL symbol(s) may be referred to as UL RO, and a RO in SBFD symbol(s) may be referred to as SBFD RO.

[0087] SSB-to-RO mapping

[0088] The mapping of SSB indices (also referred to as the beam indices of the SSBs, or the SSB beams, or simply SSBs) to the determined ROs is fundamental for a UE to understand which ROs are associated to the SSB index selected during the preliminary step before the start of the RACH procedure. The different SSB indexes are beamformed in different directions in the cell, hence selection of a wrong SSB index may entail failure of the RACH procedure.

[0089] To this purpose, one fundamental parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB is configured in RACH-ConfigCommon and indicates two information: (i) the number of SS / PBCH block indexes (or preamble sets) per RO and (ii) the number of contention-based preambles per SS / PBCH block index (or preamble set). More precisely, for Type-1 random access procedure, a UE is provided a number N of SS / PBCH block indexes associated with one PRACH occasion and a number R of contention-based preambles per SS / PBCH block index per valid PRACH occasion by ssb-perRACH-OccasionAndCB-PreamblesPerSSB. Once this information is available to a UE, the UE maps the SSB indexes to the time-frequency grid of ROs (determined as described above) in increasing order of frequency resource indices, time resource indices of the ROs within a PRACH slots, and the PRACH slots, sequentially. In this disclose, it may focus on the information related to the number of SSBs per ROs, therefore ssb-perRACH-OccasionAndCB-PreamblesPerSSB may be referred to as ssb-perRACH-Occasion for the sake of brevity.

[0090] FIG. IB illustrates an example of valid ROs in one frame, and further assumes the following additional configuration: DDDSU slot structure, Msgl-FDM = 2, and ssb-perRACH-Occasion is 1 / 2. Based on the configuration, two ROs are multiplexed in the frequency domain (Msgl-FDM = two) and any two ROs are mapped to the same SSB index (ssb-perRACH-Occasion = 1 / 2) in the order of frequency-first and time-second manner, until all SSB indices are mapped. In this example, the normal (for example, legacy) RO validation rules are assumed such that the ROs that overlapped with DL symbols are invalid (i.e., ROs 4-7 in FIG. IB).

[0091] SBFD

[0092] 3GPP 5G NR supports two duplexing modes: FDD for paired bands and TDD for unpaired bands. Irrespective of the duplexing mode, uplink and downlink phases are separated in time domain. This may create unnecessary latency, possibly reduce coverage and capacity depending on the considered layout. In TDD deployments, the situation is further exacerbated by the fact that the scheduling offers lower dynamism, i.e., the slot structure is fixed and does not change very often in practice. This may result in rather limited time duration for the uplink in TDD.

[0093] It is studied on the evolution of duplexing operation in NR that addresses the challenges above. One of the objectives is to allow the gNB to do simultaneous DL transmission and UL reception on different physical resource blocks (PRBs) / subbands within an unpaired wideband NR cell. In this disclosure, this is referred to as subband non overlapping full duplex (SBFD). In other sources, this duplexing scheme is also referred to as cross-division duplexing (xDD) scheme or flexible duplexing (FDU).

[0094] FIG. IC illustrates an example of SBFD and non-SBFD slots. From the above description of SBFD operation, it can be observed that there are two slot types for both DL and UL transmissions as shown in FIG. IC, namely: SBFD slots, during which the nonoverlapping DL subband(s) and UL subband(s) both exist; and non-SBFD slots, during which the entire band is used for either DL or UL (i.e., legacy / full DL / UL slots).

[0095] In SBFD slots, a guardband is expected to be placed between DL and UL resource blocks (RBs). This provides better isolation between UL and DL transmissions and is expected to be essential for reducing the impact of the self-interference (due to gNB’s own DL transmissions and the gNB’s own UL reception) as well as cross-link interference (CLI) between UE to UE links, and gNB to gNB links

[0096] Generally, an SBFD-aware UE may be configured with either one of the following.

[0097] PRACH configuration Option 1. Based on this single configuration, SBFD ROs are determined by using a single RACH configuration, as shown in FIG. 2A. As illustrated in the example in FIG. 2A, 4 SSBs are considered, where two ROs are multiplexed in the frequency domain (msgl-FDM = 2) and one SSB is mapped to one RO (ssb-perRACH-occasion = 1). This example also assumes 1 SBFD RO out of 2 ROs in time domain due to the fact that these ROs are in UL sub-band of SBFD symbols. It’s worth noting that the SBFD ROs are transparent to normal (for example, legacy) UEs and being valid for only SBFD-aware UEs. For Option 1, SSBs are separately mapped to SBFD ROs and UL ROs.

[0098] PRACH configuration Option 2. Two separate RACH configurations are used, where a first configuration is the normal (for example, legacy) configuration which configures only normal (for example, legacy) UL ROs (these UL ROs are usable by both normal (for example, legacy) UEs and SBFD-aware UEs). A second configuration is an additional configuration for configuring the SBFD UEs. These two cases of PRACH configuration Option 2 may be referred to as Option 2-1 and Option 2-2 respectively. Moreover, Option 2-1 may support long length SBFD RO which can cross the SBFD slot to the UL slot. For simplicity, the long length SBFD RO may be referred to as SBFD LL-RO.

[0099] It should be noted that, in Option 2-1, the second configuration may only configure SBFD ROs, and in Option 2-2, the second configuration may configure both SBFD ROs and UL ROs. Moreover, since the second configuration is an additional configuration for configuring the SBFD UEs, whether only the SBFD ROs are configured or the SBFD ROs and the UL ROs are configured may depend on Option 2-1 or Option 2-2 respectively.

[00100] FIG. 2B illustrates an example of PRACH configuration Option 2-1 with the first and the second configurations are configured with 4 SSBs, where two ROs are multiplexed in the frequency domain (msgl-FDM = 2), and one SSB is mapped to one RO (ssb-perRACH-occasion = 1). For the first and the second configurations, this example illustrates these parameters separately for the sake of brevity.

[00101] FIG. 2C illustrates an example of PRACH configuration Option 2-1 with SBFD LL-ROs. The first and the second configurations are configured with 4 SSBs, where two ROs are multiplexed in the frequency domain (msgl-FDM = 2), and one SSB is mapped to one RO (ssb-perRACH-occasion = 1). In this example, the mapping of SSB to the ROs configured by the second configuration for the SBFD LL-ROs is not illustrated. In this disclosure, it may focus on this case for Option 2-1.

[00102] FIG. 2D illustrates an example of PRACH configuration Option 2-2 with the first and the second configurations are configured with 4 SSBs, where two ROs are multiplexed in the frequency domain (msgl-FDM = 2), and one SSB is mapped to one RO (ssb-perRACH-occasion = 1). The UL ROs configured by the second configuration are valid and shown in this figure. In this example, the mapping of SSB to the ROs configured by the second configuration is not illustrated. In FIG. 2D, SSBs are mapped separately to SBFD ROs and UL ROs configured by the second configuration.

[00103] It should be noted that, for simplicity, the TDD patterns in any of the presented examples are not mentioned. However, for the sake of clarifying the issue, a different TDD pattern might be used in some of the examples (e.g., all examples showing LL-ROs have different TDD patterns from the rest of the examples).

[00104] This disclosure focuses on the PRACH configuration considering two cases (i.e., Option 2-1 and Option 2-2). Option 2-1 covers the case of long-length (LL) SBFD ROs with SBFD RO crossing between the SBFD slot and UL slot. Option 2-2 covers the case of the proposed (for example, new) UL ROs configured by the second RACH configuration.

[00105] For the first case (i.e., Option 2-1), to better highlight the issue in Option 2-1, it focuses on how to map SSBs to the LL-ROs configured by the second configuration as illustrated in FIG. 2C. FIG. 3 A reconsider the example in FIG. 2C, while applying the higher-layer parameter ssb-perRACH-occasion-2 configured by the second configuration to configure the SSB-to-RO mapping for all SBFD LL-ROs.

[00106] For the second case (i.e., Option 2-2), similar to the previous case and as illustrated in FIG. 2D, it focuses on how to map SSBs to the ROs configured by the second configuration. One alternative is to apply the higher-layer parameter ssb-perRACH-occasion-2 configured by the second configuration for all ROs configured by the second configuration. FIG. 3B reconsiders the example in FIG. 2D and applies the mapping of SSBs to all ROs configured by the second configuration.

[00107] Another alternative is to apply the higher-layer parameter ssb-perRACH-occasion-2 configured by the second configuration separately for the SBFD ROs and UL ROs configured by the second configuration. FIG. 3C illustrates an example of Option 2-2 where the first and the second configurations are configured with 4 SSBs, two ROs are multiplexed in the frequency domain (msgl-FDM = 2) and one SSB is mapped to one RO (ssb-perRACH-occasion = 1). In this example, SBFD ROs appear once every 3 ROs in time domain. SSBs are mapped separately to SBFD ROs and UL ROs configured by the second configuration.

[00108] Both of the above cases lead to a scenario that, at the time instance when the normal (for example, legacy) UL ROs and the SBFD LL-ROs (in the first case) / UL ROs (in the second case) configured by the second configuration are overlapped, the network (NW) may need to enable more SSBs (at the same time) than that compared to the normal (for example, legacy). For example, in FIG. 3B, at the highlighted time instance, the network (NW) may need to enable all 4 SSBs instead of enabling only 2 SSBs (SSB #0 and SSB #1) compared to the normal (for example, legacy).

[00109] The problems with the above cases are twofold as following.

[00110] First, this either restricts the scheduler or increases the complexity at the network (NW). Indeed, NW may need to either carefully select a combination of configuration to avoid such scenario or enable more beams at the same time.

[00111] Second, enabling more beams at the same time also leads to a shorter coverage of the beams (lower RSRP) compared to the other time instances where fewer beams are enabled.

[00112] It is worth noting that the scenario is even more likely to happen when the UL ROs / SBFD LL-ROs configured by the second configuration are not fully overlapped / aligned in time with the normal (for example, legacy) UL ROs (e.g., UL ROs configured by the second configuration are overlapped in time with normal (for example, legacy) UL ROs and some are not) or not having the same number of frequency indices (msgl-FDM).

[00113] Therefore, some embodiments of the present disclosure propose a solution for SSB-to-RO mapping, especially for SSB-to-RO mapping in SBFD. In this solution, a terminal device receives a first random access channel (RACH) configuration and a second RACH configuration. The first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs. Then, the terminal device determines a first set of ROs among second ROs configured by the second RACH configuration, and the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration. The terminal device determines, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, and the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO. In addition, the terminal device determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, and the second set of ROs do not overlap in time with the first ROs.

[00114] Moreover, some embodiments of the present disclosure propose another solution for SSB-to-RO mapping, especially for SSB-to-RO mapping in SBFD. In this solution, a terminal device receives a first random access channel (RACH) configuration and a second RACH configuration. The first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs. Then, the terminal device determines a first set of ROs among second ROs configured by the second RACH configuration, and the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration. In addition, the terminal device determine, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, and the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlap in time with the at least one second RO.

[00115] Furthermore, some embodiments of the present disclosure propose a further solution for SSB-to-RO mapping, especially for SSB-to-RO mapping in SBFD. In this solution, a terminal device receives a first random access channel (RACH) configuration and a second RACH configuration. The first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs. Then, the terminal device determines a first set of ROs among second ROs configured by the second RACH configuration, and the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; and the terminal device determines, for the first set of ROs, at least one second SSB index for the second mapping. In addition, the terminal device determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, and the second set of ROs do not overlap in time with the first ROs.

[00116] For example, this disclosure proposes a method of mapping SSBs to ROs configured by the second configuration for SBFD LL-ROs in Option 2-1 (the first case) and UL ROs for Option 2-2 (the second case). The method comprises the following two steps.

[00117] First, at the time instance when the normal (for example, legacy) UL ROs and the proposed (for example, new) SBFD LL-ROs / UL ROs configured by the second configuration are overlapped (in time domain), the same SSB index(s) used for mapping the normal (for example, legacy) UL ROs will be used for mapping the overlapping proposed (for example, new) ROs (i.e., SBFD LL-ROs for the first case or the proposed (for example, new) UL ROs for the second case).

[00118] If the number of normal (for example, legacy) UL ROs and the proposed (for example, new) ROs in the time instance are the same, the same mapping applied for normal (for example, legacy) UL ROs is applied for proposed (for example, new) ROs. If the number of normal (for example, legacy) UL ROs (N) is greater than the number of proposed (for example, new) ROs (M) in the time instance, the mapping for the M proposed (for example, new) ROs are the same as the first (or last) M normal (for example, legacy) UL ROs counted in the order of frequency indices.

[00119] For SBFD LL-ROs, if the number of the normal (for example, legacy) UL ROs (N) is lower than the number of the proposed (for example, new) SBFD LL-ROs (M) in the subset, the mapping of the first (or last) N of the M the proposed (for example, new) SBFD LL- ROs are the same as the N normal (for example, legacy) UL ROs counted in the order of frequency indices.

[00120] Second, SSBs will be mapped to the remaining ROs configured by the second configuration (including SBFD ROs and the proposed (for example, new) UL ROs that are not overlapped with normal (for example, legacy) UL ROs, if any for the second case) using the higher-layer parameter ssb-perRACH-occasion-2 configured by the second configuration.

[00121] The proposed approach ensures that, at a given time instance, the same SSBs will be used for the proposed (for example, new) ROs and the normal (for example, legacy) UL ROs if they are overlapped in time domain.

[00122] For illustrative purposes, principles and example embodiments of the present disclosure will be described below with reference to FIG. 1A to FIG. 19. However, it is to be noted that these embodiments are given to enable the skilled in the art to understand inventive concepts of the present disclosure and implement the solution as proposed herein, and not intended to limit scope of the present application in any way.

[00123] FIG. 4 illustrates an example of a process flow 400 in accordance with some example embodiments of the present disclosure. For ease of understanding, the process flow 400 will be described with reference to FIG. 1 A. It would be appreciated that although the process flow 400 has been described referring to the communication procedure 100 of FIG. 1A, this process flow 400 may be likewise applied to other similar communication procedures.

[00124] As shown in FIG. 4, at 410, a network device 110 may transmit, to a terminal device 120, a first random access channel (RACH) configuration and a second RACH configuration 412. The first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs.

[00125] Accordingly, at 414, the terminal device 120 may receive the first random access channel (RACH) configuration and the second RACH configuration 412. At 420, the terminal device 120 may determine a first set of ROs among second ROs configured by the second RACH configuration. The first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration.

[00126] At 430, the terminal device 120 may determine, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping. The at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO. And at 440, the terminal device 120 may determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping. The second set of ROs do not overlap in time with the first ROs.

[00127] Thereafter, at 454, the network device 110 may receive, from the terminal device 120, a physical random access channel (PRACH) preamble, which is transmitted at 450 by the terminal device 120, on at least one of the second ROs with at least one SSB index.

[00128] In some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is the same as a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the at least one first SSB index based on a same mapping that is applied for the at least one second RO or the at least one first RO.

[00129] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is greater than a number M of the at least one second RO, determining the at least one second SSB index to be the same as the first or last M of the at least one first SSB index as counted in an order of frequency indices based on a same mapping that is applied for the at least one second RO or the first or last M of the at least one first RO as counted in an order of frequency indices.

[00130] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining the first or last N of the at least one second SSB index as counted in an order of frequency indices to be the same as the at least one first SSB index based on a same mapping that is applied for the first or last N of the at least one second RO as counted in an order of frequency indices or the at least one first RO.

[00131] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index as follows. Based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, the terminal device may determine one or more groups of N SSB indexes among the at least one second SSB index based on a same mapping that is applied for the group of N SSB indexes of the at least one second RO as counted in an order of frequency indices or the at least one first RO. The group of N SSB indexes as counted in an order of frequency indices is the same as the at least one first SSB index, and N is greater than or equal to 1.

[00132] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the terminal device may determine the at least one third SSB index by: for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed across SBFD ROs and UL ROs configured by the second RACH configuration jointly.

[00133] Alternatively, in some embodiments, the terminal device may determine the at least one third SSB index by: for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed for SBFD ROs and UL ROs configured by the second RACH configuration separately.

[00134] In some embodiments, the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

[00135] In some embodiments, the second ROs at least comprise a RO set including a group of consecutive ROs, the RO set has a size in number of ROs that is equal to a number of configured SSBs, and the RO set covers indexes of the configured SSBs. Furthermore, in some embodiments, the RO set at least comprises the at least one second RO and at least one further RO among the second set of ROs.

[00136] In some embodiments, the terminal device may further transmit a physical random access channel (PRACH) preamble on at least one of the second ROs with the at least one second SSB index and the at least one third SSB index.

[00137] FIG. 5 illustrates another example of a process flow 500 in accordance with some example embodiments of the present disclosure. For ease of understanding, the process flow 500 will be described with reference to FIG. 1 A. It would be appreciated that although the process flow 500 has been described referring to the communication procedure 100 of FIG. 1A, this process flow 500 may be likewise applied to other similar communication procedures.

[00138] As shown in FIG. 5, at 510, a network device 110 may transmit, to a terminal device 120, a first random access channel (RACK) configuration and a second RACH configuration 512. The first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs.

[00139] Accordingly, at 514, the terminal device 120 may receive the first random access channel (RACH) configuration and the second RACH configuration 512. At 520, the terminal device 120 may determine a first set of ROs among second ROs configured by the second RACH configuration. The first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration.

[00140] At 530, the terminal device 120 may determine, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping. The at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO.

[00141] Thereafter, at 554, the network device 110 may receive, from the terminal device 120, a physical random access channel (PRACH) preamble, which is transmitted at 550 by the terminal device 120, on at least one of the second ROs with at least one SSB index.

[00142] In some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is the same as a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the at least one first SSB index based on a same mapping that is applied for the at least one second RO or the at least one first RO.

[00143] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is greater than a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the first or last M of the at least one first SSB index as counted in an order of frequency indices based on a same mapping that is applied for the at least one second RO or the first or last M of the at least one first RO as counted in an order of frequency indices.

[00144] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining the first or last N of the at least one second SSB index as counted in an order of frequency indices to be the same as the at least one first SSB index based on a same mapping that is applied for the first or last N of the at least one second RO as counted in an order of frequency indices or the at least one first RO.

[00145] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index as follows. Based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, the terminal device may determine one or more groups of N SSB indexes among the at least one second SSB index based on a same mapping that is applied for the group of N SSB indexes of the at least one second RO as counted in an order of frequency indices or the at least one first RO. The group of N SSB indexes as counted in an order of frequency indices is the same as the at least one first SSB index, and N is greater than or equal to 1.

[00146] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. In some embodiments, the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

[00147] In some embodiments, the terminal device may further determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping. The second set of ROs do not overlap in time with the first ROs. The terminal device may transmit a physical random access channel (PRACH) preamble on at least one of the second ROs with the at least one second SSB index and the at least one third SSB index.

[00148] FIG. 6 illustrates a further example of a process flow 600 in accordance with some example embodiments of the present disclosure. For ease of understanding, the process flow 600 will be described with reference to FIG. 1 A. It would be appreciated that although the process flow 400 has been described referring to the communication procedure 100 of FIG. 1A, this process flow 600 may be likewise applied to other similar communication procedures.

[00149] As shown in FIG. 6, at 610, a network device 110 may transmit, to a terminal device 120, a first random access channel (RACH) configuration and a second RACH configuration 612. The first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs.

[00150] Accordingly, at 614, the terminal device 120 may receive the first random access channel (RACH) configuration and the second RACH configuration 612. At 620, the terminal device 120 may determine a first set of ROs among second ROs configured by the second RACH configuration. The first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration.

[00151] At 630, the terminal device 120 may determine, for the first set of ROs, at least one second SSB index for the second mapping. And at 640, the terminal device 120 may determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping. The second set of ROs do not overlap in time with the first ROs.

[00152] Thereafter, at 654, the network device 110 may receive, from the terminal device 120, a physical random access channel (PRACH) preamble, which is transmitted at 650 by the terminal device 120, on at least one of the second ROs with at least one SSB index.

[00153] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the terminal device may determine the at least one third SSB index by: for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed across SBFD ROs and non-SBFD UL ROs of the second set of ROs jointly.

[00154] Alternatively, in some embodiments, the terminal device may determine the at least one third SSB index by: for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed for SBFD ROs and non-SBFD UL ROs of the second set of ROs separately.

[00155] In some embodiments, the second ROs at least comprise a RO set including a group of consecutive ROs, the RO set has a size in number of ROs that is equal to a number of configured SSBs, and the RO set covers indexes of the configured SSBs. Furthermore, in some embodiments, the RO set at least comprises the at least one second RO and at least one further RO among the second set of ROs.

[00156] In some embodiments, the terminal device may further transmit a physical random access channel (PRACH) preamble on at least one of the second ROs with the at least one second SSB index and the at least one third SSB index.

[00157] FIG. 7 illustrates an example message sequence flowchart 700 for the second case in 4 steps in accordance with some example embodiments of the present disclosure. Details of these steps are as follows.

[00158] At 710 (e.g., Step 1), the terminal device 120 (e.g., the UE) may receive from the network device 110 (e.g., the NW) the following.

[00159] A SBFD configuration, which provides information on the location of SBFD symbols and UL and DL sub-bands in the SBFD symbols. A first and a second PRACH configurations, which provide information on the location of ROs in time and frequency domains. The first configuration consists of a first SSB-to-RO mapping information (ssb-perRACH-occasion-1), which provides information about the mapping of SSBs to the normal (for example, legacy) UL ROs configured by the first configuration. And the second configuration consists of a second SSB-to-RO mapping information (ssb-perRACH-occasion-2), which provides information about the mapping of SSBs to the SBFD RO and the proposed (for example, new) UL ROs configured by the second configuration, excluding the proposed (for example, new) UL ROs that overlap in time with the normal (for example, legacy) UL ROs.

[00160] At 720 (e g., Step 2), the UE may determine two types of ROs, namely SBFD ROs and UL ROs, thanks to the SBFD and the PRACH configurations. And at 720, the UE may determine a set of proposed (for example, new) UL ROs configured by the second configuration that overlap in time with the normal (for example, legacy) UL ROs.

[00161] Moreover, at 720, for each sub-set of proposed (for example, new) UL RO(s) that has the same time allocation in the set, the UE may determine the SSB index(s) associated with the normal (for example, legacy) UL ROs that overlapped with the proposed (for example, new) UL RO(s) in the sub-set. If the number of normal (for example, legacy) UL ROs and the proposed (for example, new) UL ROs are the same (i e., msgl-FDM-1 equals to msgl-FDM-2), the same mapping applied for normal (for example, legacy) UL ROs is applied for proposed (for example, new) UL ROs. If the number of normal (for example, legacy) UL ROs (N) is greater than the number of proposed (for example, new) UL ROs (M) in the sub-set, the mapping for the M proposed (for example, new) UL ROs are the same as the first (or last) M normal (for example, legacy) UL ROs counted in the order of frequency indices.

[00162] At 740 (e.g., Step 3), for option A (i.e., continuous mapping), the UE may map SSBs to the remaining ROs configured by the second configuration, i.e., excluding the proposed (for example, new) UL ROs in the set, using the higher-layer parameter ssb-perRACH-occasion-2 configured by the second configuration. The mapping of SSBs to ROs is performed across SBFD and UL ROs jointly, i.e., continuous mapping.

[00163] At 740, for option B (i.e., separate mapping), the UE may map SSBs to the remaining ROs configured by the second configuration, i.e., excluding the proposed (for example, new) UL ROs in the set, using the higher-layer parameter ssb-perRACH-occasion-2 configured by the second configuration. The mapping of SSBs to ROs is performed separately for the SBFD ROs and for the remaining UL ROs, i.e., separate mapping.

[00164] At 750 (e.g., Step 4), the UE may transmits a PRACH preamble on at least one of the ROs with the corresponding SSB indices determined at 720.

[00165] FIG. 8A illustrates an example of SSB-to-RO mapping with continuous mapping in accordance with some example embodiments of the present disclosure; FIG. 8B illustrates an example of SSB-to-RO mapping with separate mapping in accordance with some example embodiments of the present disclosure; and FIG. 8C illustrates an example of SSB-to-RO mapping in the case that msgl-FDM-1 is greater than msgl-FDM-2 in accordance with some example embodiments of the present disclosure.

[00166] As illustrated in FIG. 8A, it reconsiders the example in FIG. 3C but using the proposed mapping at 740, option A. In FIG. 8A, since the number of normal (for example, legacy) UL ROs and the proposed (for example, new) UL ROs are the same (i.e., msgl- FDM-1 equals to msgl -FDM-2), the same mapping applied for normal (for example, legacy) UL ROs is applied for proposed (for example, new) UL ROs.

[00167] Moreover, in FIG. 8A, the UE may map SSBs to the remaining ROs configured by the second configuration, i e., excluding the proposed (for example, new) UL ROs in the set, using the higher-layer parameter ssb-perRACH-occasion-2 configured by the second configuration. The mapping of SSBs to ROs is performed across SBFD and UL ROs jointly, i.e., continuous mapping.

[00168] As illustrated in FIG. 8B, it reconsiders the example in FIG. 3C but using the proposed mapping at 740, option B. In FIG. 8A, since the number of normal (for example, legacy) UL ROs and the proposed (for example, new) UL ROs are the same (i.e., msgl-FDM-1 equals to msgl -FDM-2), the same mapping applied for normal (for example, legacy) UL ROs is applied for proposed (for example, new) UL ROs.

[00169] Moreover, in FIG. 8B, the UE may map SSBs to the remaining ROs configured by the second configuration, i.e., excluding the proposed (for example, new) UL ROs in the set, using the higher-layer parameter ssb-perRACH-occasion-2 configured by the second configuration. The mapping of SSBs to ROs is performed separately for the SBFD ROs and for the remaining UL ROs, i.e., separate mapping.

[00170] As illustrated in FIG. 8C, 4 SSBs and one SSB to one RO are configured in the first and the second configuration. The ROs in the first configuration are multiplexed in frequency domain with msgl-FDM-1 = 2, while the ROs in the second configuration are not multiplexed in frequency domain, i.e., msgl-FDM-2 = 1. SBFD ROs happen once every two ROs in time domain for the second configuration. The proposed mapping is considered in this example.

[00171] In FIG. 8C, since the number of normal (for example, legacy) UL ROs (N) is greater than the number of proposed (for example, new) UL ROs (M) in the sub-set (i.e., msgl-FDM-1 is greater than msgl -FDM-2), the mapping for the M proposed (for example, new) UL ROs are the same as the first (or last) M normal (for example, legacy) UL ROs counted in the order of frequency indices.

[00172] Furthermore, as a consequence of the proposed SSB-to-RO mapping, certain SSBs are mapped more often than others. This results in unfairness across the SSBs which might impact the random access performance by delaying the Msgl / MsgA transmission if the selected SSB is no longer mapped to the original RACH occasion. Note, for example in FIG. 8A, that the maximum distance between UL ROs that map SSB#0 and SSB#1 is 5 ROs, instead of the original 2 ROs (before applying the proposed mapping)

[00173] To solve this issue, it proposes introducing the concept of RO set. A RO set is defined as a group of consecutive ROs whose size (in number of ROs) is equal to the number of configured SSBs. To ensure fairness, each RO set must contain / cover all the SSBs indexes. The concept of RO set can be used for continuous and separate mapping (option A and option B at 740 above, respectively). The application of the RO set occurs after 740 described above.

[00174] As illustrated in FIG. 9A, it reconsiders the example in FIG. 8A (with continuous mapping) and introduces the RO sets to ensure fairness. Given that each RO set should cover all the configured SSBs indexes, the UE perform additional changes to the second configuration ROs. In this case, the maximum distance between UL ROs is reduced to 3 ROs. The changes in SSB mapping due to RO sets and fairness are highlighted in the blocks with text in bold and underlined.

[00175] Moreover, as illustrated in FIG. 9B, it reconsiders the example in FIG. 8B (with separate mapping) and introduces the RO sets to ensure fairness. Note that since separate RO mapping is used, the RO sets are only formed by ROs of the same type, specifically, UL ROs. Given that each RO set should cover all the configured SSBs indexes, the UE perform additional changes to the SSB mapping to UL ROs. The changes in SSB mapping due to RO sets and fairness are highlighted in the blocks with text in bold and underlined.

[00176] FIG. 10 illustrates an example message sequence flowchart 1000 for the first case in accordance with some example embodiments of the present disclosure.

[00177] At 1010 (e.g., Step 1), the terminal device 120 (e.g., the UE) may receive from the network device 110 (e.g., the NW) the following.

[00178] A SBFD configuration, which provides information on the location of SBFD symbols and UL and DL sub-bands in the SBFD symbols. A first and a second PRACH configurations, which provide information on the location of ROs in time and frequency domains. The first configuration consists of a first SSB-to-RO mapping information (ssb-perRACH-occasion-1), which provides information about the mapping of SSBs to the normal (for example, legacy) UL ROs configured by the first configuration. The second configuration consists of a second SSB-to-RO mapping information (ssb-perRACH- occasion-2), which provides information about the mapping of SSBs to the SBFD RO.

[00179] At 1020 (e.g., Step 2), the UE may determine the long length (LL) SBFD ROs thanks to the SBFD and the PRACH configurations.

[00180] Moreover, at 1020, the UE may determine a set of proposed (for example, new) SBFD LL-ROs configured by the second configuration that overlap in time with the normal (for example, legacy) UL ROs.

[00181] Moreover, at 1020, for each sub-set of proposed (for example, new) SBFD LL-RO(s) that has the same time allocation in the set, the UE may determine the SSB index(s) associated with the normal (for example, legacy) UL ROs that overlapped with the proposed (for example, new) SBFD LL-RO(s) in the sub-set. If the number of normal (for example, legacy) UL ROs and the proposed (for example, new) SBFD LL-ROs are the same (i.e., msgl-FDM-1 equals to msgl-FDM-2), the same mapping applied for normal (for example, legacy) UL ROs is applied for proposed (for example, new) SBFD LL-ROs. If the number of normal (for example, legacy) UL ROs (N) is greater than the number of proposed (for example, new) SBFD LL-ROs (M) in the sub-set, the mapping for the M proposed (for example, new) SBFD LL-ROs are the same as the first (or last) N normal (for example, legacy) UL ROs counted in the order of frequency indices. If the number of normal (for example, legacy) UL ROs (N) is lower than the number of proposed (for example, new) SBFD LL-ROs (M) in the sub-set, the mapping of the first (or last) N of the M proposed (for example, new) SBFD LL-ROs are the same as the N normal (for example, legacy) UL ROs counted in the order of frequency indices.

[00182] At 1050 (e.g., Step 3), the UE may map the remaining SSBs to the remaining ROs configured by the second configuration, i.e., excluding the proposed (for example, new) SBFD LL-ROs in the set, using the higher-layer parameter ssb-perRACH-occasion-2 configured by the second configuration. Thereafter (e.g., at Step 4, which is not shown in FIG. 10), the UE may transmit a PRACH preamble on at least one of the ROs with the corresponding SSB indices determined at 1020.

[00183] FIG. 11A illustrates an example of SSB-to-RO mapping for SBFD LL-ROs in the case that msgl-FDM-1 is equal to msgl-FDM-2 in accordance with some example embodiments of the present disclosure; FIG. 11B illustrates an example of SSB-to-RO mapping for SBFD LL-ROs in the case that msgl-FDM-1 is greater than msgl-FDM-2 in accordance with some example embodiments of the present disclosure; FIG. 1 IC illustrates an example of SSB-to-RO mapping for SBFD LL-ROs in the case that msgl-FDM-1 is less than msgl-FDM-2 in accordance with some example embodiments of the present disclosure; and FIG. 11D illustrates an another example of SSB-to-RO mapping for SBFD LL-ROs in the case that msgl-FDM-1 is less than msgl-FDM-2 in accordance with some example embodiments of the present disclosure.

[00184] FIG. 12 illustrates a flowchart of an example method 1200 implemented at a terminal device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1200 will be described from the perspective of the terminal device 120 with reference to FIG. 4.

[00185] At block 1210, the terminal device may receive a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs. At block 1220, the terminal device may determine a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration. At block 1230, the terminal device may determine, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO. At block 1240, the terminal device may determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[00186] In some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is the same as a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the at least one first SSB index based on a same mapping that is applied for the at least one second RO or the at least one first RO.

[00187] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is greater than a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the first or last M of the at least one first SSB index as counted in an order of frequency indices based on a same mapping that is applied for the at least one second RO or the first or last M of the at least one first RO as counted in an order of frequency indices.

[00188] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining the first or last N of the at least one second SSB index as counted in an order of frequency indices to be the same as the at least one first SSB index based on a same mapping that is applied for the first or last N of the at least one second RO as counted in an order of frequency indices or the at least one first RO.

[00189] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining one or more groups of N SSB indexes among the at least one second SSB index based on a same mapping that is applied for the group of N SSB indexes of the at least one second RO as counted in an order of frequency indices or the at least one first RO, wherein the group of N SSB indexes as counted in an order of frequency indices is the same as the at least one first SSB index, and N is greater than or equal to 1.

[00190] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the terminal device may determine the at least one third SSB index by: for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed across SBFD ROs and UL ROs configured by the second RACH configuration j ointly.

[00191] Alternatively, in some embodiments, the terminal device may determine the at least one third SSB index by: for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed for SBFD ROs and UL ROs configured by the second RACH configuration separately.

[00192] In some embodiments, the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

[00193] In some embodiments, the second ROs at least comprise a RO set including a group of consecutive ROs, and the RO set has a size in number of ROs that is equal to a number of configured SSBs, and wherein the RO set covers indexes of the configured SSBs. Furthermore, in some embodiments, the RO set at least comprises the at least one second RO and at least one further RO among the second set of ROs.

[00194] In some embodiments, the terminal device may further transmit a physical random access channel (PRACH) preamble on at least one of the second ROs with the at least one second SSB index and the at least one third SSB index.

[00195] FIG. 13 illustrates a flowchart of an example method 1300 implemented at a network device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1300 will be described from the perspective of the network device 110 with reference to FIG. 4.

[00196] At block 1310, the network device may transmit, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs. At block 1320, the network device may receive, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[00197] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

[00198] In some embodiments, the second ROs at least comprise a RO set including a group of consecutive ROs, and the RO set has a size in number of ROs that is equal to a number of configured SSBs, and wherein the RO set covers indexes of the configured SSBs.

[00199] In some embodiments, an apparatus capable of performing any of the method 1200 (for example, the terminal device 120) may comprise means for performing the respective steps of the method 1200. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[00200] In some embodiments, the apparatus comprises means for receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; means for determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; means for determining, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO; and means for determining, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[00201] In some embodiments, the means for determining the at least one second SSB index may comprise: means for based on a determination that a number N of at least one overlapping RO of the at least one first RO is the same as a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the at least one first SSB index based on a same mapping that is applied for the at least one second RO or the at least one first RO.

[00202] Alternatively, in some embodiments, the means for determining the at least one second SSB index may comprise: means for based on a determination that a number N of at least one overlapping RO of the at least one first RO is greater than a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the first or last M of the at least one first SSB index as counted in an order of frequency indices based on a same mapping that is applied for the at least one second RO or the first or last M of the at least one first RO as counted in an order of frequency indices.

[00203] Alternatively, in some embodiments, the means for determining the at least one second SSB index may comprise: means for based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining the first or last N of the at least one second SSB index as counted in an order of frequency indices to be the same as the at least one first SSB index based on a same mapping that is applied for the first or last N of the at least one second RO as counted in an order of frequency indices or the at least one first RO.

[00204] Alternatively, in some embodiments, the means for determining the at least one second SSB index may comprise: means for based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining one or more groups of N SSB indexes among the at least one second SSB index based on a same mapping that is applied for the group of N SSB indexes of the at least one second RO as counted in an order of frequency indices or the at least one first RO, wherein the group of N SSB indexes as counted in an order of frequency indices is the same as the at least one first SSB index, and N is greater than or equal to 1.

[00205] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the means for determining the at least one third SSB index may comprise: means for, for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed across SBFD ROs and UL ROs configured by the second RACH configuration jointly.

[00206] Alternatively, in some embodiments, the means for determining the at least one third SSB index may comprise: means for, for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed for SBFD ROs and UL ROs configured by the second RACH configuration separately.

[00207] In some embodiments, the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

[00208] In some embodiments, the second ROs at least comprise a RO set including a group of consecutive ROs, and the RO set has a size in number of ROs that is equal to a number of configured SSBs, and wherein the RO set covers indexes of the configured SSBs. Furthermore, in some embodiments, the RO set at least comprises the at least one second RO and at least one further RO among the second set of ROs.

[00209] In some embodiments, the apparatus may further comprise means for transmitting a physical random access channel (PRACH) preamble on at least one of the second ROs with the at least one second SSB index and the at least one third SSB index.

[00210] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1200. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[00211] In some embodiments, an apparatus capable of performing any of the method 1300 (for example, the network device 110) may comprise means for transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and means for receiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[00212] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

[00213] In some embodiments, the second ROs at least comprise a RO set including a group of consecutive ROs, and the RO set has a size in number of ROs that is equal to a number of configured SSBs, and wherein the RO set covers indexes of the configured SSBs.

[00214] FIG. 14 illustrates a flowchart of another example method 1400 implemented at a terminal device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1400 will be described from the perspective of the terminal device 120 with reference to FIG. 5.

[00215] At block 1410, the terminal device may receive a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs. At block 1420, the terminal device may determine a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration. At block 1430, the terminal device may determine, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO.

[00216] In some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is the same as a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the at least one first SSB index based on a same mapping that is applied for the at least one second RO or the at least one first RO.

[00217] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is greater than a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the first or last M of the at least one first SSB index as counted in an order of frequency indices based on a same mapping that is applied for the at least one second RO or the first or last M of the at least one first RO as counted in an order of frequency indices.

[00218] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining the first or last N of the at least one second SSB index as counted in an order of frequency indices to be the same as the at least one first SSB index based on a same mapping that is applied for the first or last N of the at least one second RO as counted in an order of frequency indices or the at least one first RO.

[00219] Alternatively, in some embodiments, the terminal device may determine the at least one second SSB index by: based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining one or more groups of N SSB indexes among the at least one second SSB index based on a same mapping that is applied for the group of N SSB indexes of the at least one second RO as counted in an order of frequency indices or the at least one first RO, wherein the group of N SSB indexes as counted in an order of frequency indices is the same as the at least one first SSB index, and N is greater than or equal to 1.

[00220] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

[00221] In some embodiments, the terminal device may further determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs; and transmit a physical random access channel (PRACH) preamble on at least one of the second ROs with the at least one second SSB index and the at least one third SSB index.

[00222] FIG. 15 illustrates a flowchart of another example method 1500 implemented at a network device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1500 will be described from the perspective of the network device 110 with reference to FIG. 5.

[00223] At block 1510, the network device may transmit, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs. At block 1520, the network device may receive, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[00224] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

[00225] In some embodiments, an apparatus capable of performing any of the method 1400 (for example, the terminal device 120) may comprise means for performing the respective steps of the method 1400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[00226] In some embodiments, the apparatus comprises means for receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; means for determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; and means for determining, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO.

[00227] In some embodiments, the means for determining the at least one second SSB index may comprise: means for based on a determination that a number N of at least one overlapping RO of the at least one first RO is the same as a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the at least one first SSB index based on a same mapping that is applied for the at least one second RO or the at least one first RO.

[00228] Alternatively, in some embodiments, the means for determining the at least one second SSB index may comprise: means for based on a determination that a number N of at least one overlapping RO of the at least one first RO is greater than a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the first or last M of the at least one first SSB index as counted in an order of frequency indices based on a same mapping that is applied for the at least one second RO or the first or last M of the at least one first RO as counted in an order of frequency indices.

[00229] Alternatively, in some embodiments, the means for determining the at least one second SSB index may comprise: means for based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining the first or last N of the at least one second SSB index as counted in an order of frequency indices to be the same as the at least one first SSB index based on a same mapping that is applied for the first or last N of the at least one second RO as counted in an order of frequency indices or the at least one first RO.

[00230] Alternatively, in some embodiments, the means for determining the at least one second SSB index may comprise: means for based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining one or more groups of N SSB indexes among the at least one second SSB index based on a same mapping that is applied for the group of N SSB indexes of the at least one second RO as counted in an order of frequency indices or the at least one first RO, wherein the group of N SSB indexes as counted in an order of frequency indices is the same as the at least one first SSB index, and N is greater than or equal to 1.

[00231] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

[00232] In some embodiments, the apparatus may further comprise means for determining, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs; and means for transmitting a physical random access channel (PRACH) preamble on at least one of the second ROs with the at least one second SSB index and the at least one third SSB index.

[00233] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1400. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[00234] In some embodiments, an apparatus capable of performing any of the method 1500 (for example, the network device 110) may comprise means for transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and means for receiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[00235] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

[00236] FIG. 16 illustrates a flowchart of a further example method 1600 implemented at a terminal device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1600 will be described from the perspective of the terminal device 120 with reference to FIG. 6.

[00237] At block 1610, the terminal device may receive a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs. At block 1620, the terminal device may determine a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration. At block 1630, the terminal device may determine, for the first set of ROs, at least one second SSB index for the second mapping. At block 1640, the terminal device may determine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[00238] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the terminal device may determine the at least one third SSB index by: for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed across SBFD ROs and UL ROs configured by the second RACH configuration jointly.

[00239] Alternatively, in some embodiments, the terminal device may determine the at least one third SSB index by: for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed for SBFD ROs and UL ROs configured by the second RACH configuration separately.

[00240] In some embodiments, the second ROs at least comprise a RO set including a group of consecutive ROs, and the RO set has a size in number of ROs that is equal to a number of configured SSBs, and wherein the RO set covers indexes of the configured SSBs. Furthermore, in some embodiments, the RO set at least comprises the at least one second RO and at least one further RO among the second set of ROs.

[00241] In some embodiments, the terminal device may further transmit a physical random access channel (PRACH) preamble on at least one of the second ROs with the at least one second SSB index and the at least one third SSB index.

[00242] FIG. 17 illustrates a flowchart of a further example method 1700 implemented at a network device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1700 will be described from the perspective of the network device 110 with reference to FIG. 6.

[00243] At block 1710, the network device may transmit, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs. At block 1720, the network device may receive, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[00244] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration.

[00245] In some embodiments, the second ROs at least comprise a RO set including a group of consecutive ROs, and the RO set has a size in number of ROs that is equal to a number of configured SSBs, and wherein the RO set covers indexes of the configured SSBs. Furthermore, in some embodiments, the RO set at least comprises the at least one second RO and at least one further RO among the second set of ROs.

[00246] In some embodiments, an apparatus capable of performing any of the method 1600 (for example, the terminal device 120) may comprise means for performing the respective steps of the method 1600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[00247] In some embodiments, the apparatus comprises means for receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; means for determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration; means for determining, for the first set of ROs, at least one second SSB index for the second mapping; and means for determining, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

[00248] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration. Furthermore, in some embodiments, the means for determining the at least one third SSB index may comprise: means for, for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed across SBFD ROs and UL ROs configured by the second RACH configuration jointly.

[00249] Alternatively, in some embodiments, the means for determining the at least one third SSB index may comprise: means for, for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed for SBFD ROs and UL ROs configured by the second RACH configuration separately.

[00250] In some embodiments, the second ROs at least comprise a RO set including a group of consecutive ROs, and the RO set has a size in number of ROs that is equal to a number of configured SSBs, and wherein the RO set covers indexes of the configured SSBs. Furthermore, in some embodiments, the RO set at least comprises the at least one second RO and at least one further RO among the second set of ROs.

[00251] In some embodiments, the apparatus may further comprise means for transmitting a physical random access channel (PRACH) preamble on at least one of the second ROs with the at least one second SSB index and the at least one third SSB index.

[00252] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1600. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[00253] In some embodiments, an apparatus capable of performing any of the method 1700 (for example, the network device 110) may comprise means for transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; and means for receiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

[00254] In some embodiments, the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration.

[00255] In some embodiments, the second ROs at least comprise a RO set including a group of consecutive ROs, and the RO set has a size in number of ROs that is equal to a number of configured SSBs, and wherein the RO set covers indexes of the configured SSBs. Furthermore, in some embodiments, the RO set at least comprises the at least one second RO and at least one further RO among the second set of ROs.

[00256] FIG. 18 illustrates a simplified block diagram of a device 1800 that is suitable for implementing some example embodiments of the present disclosure. The device 1800 may be provided to implement a communication device, for example, the terminal device 120 or the network device 110 as shown in FIG. 2. As shown, the device 1800 includes one or more processors 1810, one or more memories 1820 coupled to the processor 1810, and one or more communication modules 1840 coupled to the processor 1810.

[00257] The communication module 1840 is for bidirectional communications. The communication module 1840 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

[00258] The processor 1810 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1800 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[00259] The memory 1820 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 1824, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 1822 and other volatile memories that will not last in the power-down duration.

[00260] A computer program 1830 includes computer executable instructions that are executed by the associated processor 1810. The program 1830 may be stored in the ROM 1824. The processor 1810 may perform any suitable actions and processing by loading the program 1830 into the RAM 1822.

[00261] The embodiments of the present disclosure may be implemented by means of the program 1830 so that the device 1800 may perform any process of the disclosure as discussed with reference to FIGS. 5 and 6. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[00262] In some example embodiments, the program 1830 may be tangibly contained in a computer-readable medium which may be included in the device 1800 (such as in the memory 1820) or other storage devices that are accessible by the device 1800. The device 1800 may load the program 1830 from the computer-readable medium to the RAM 1822 for execution. The computer-readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like.

[00263] FIG. 19 illustrates a block diagram of an example of a computer-readable medium 1900 in accordance with some example embodiments of the present disclosure. The computer-readable medium 1900 has the program 1830 stored thereon. It is noted that although the computer-readable medium 1900 is depicted in form of CD or DVD in FIG. 19, the computer-readable medium 1900 may be in any other form suitable for carry or hold the program 1830.

[00264] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[00265] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method 1200 or 1300 or 1400 or 1500 or 1600 or 1700 as described above with reference to FIG. 12 or 13 or 14 or 15 or 16 or 17. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[00266] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[00267] In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer-readable medium, and the like.

[00268] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e g., RAM vs. ROM).

[00269] Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular 5 embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

[00270] Although the present disclosure has been described in languages specific to 10 structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A terminal device comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to:receive a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs;determine a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration;determine, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO; anddetermine, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

2. The terminal device of claim 1, wherein the terminal device is caused to determine the at least one second SSB index by:based on a determination that a number N of at least one overlapping RO of the at least one first RO is the same as a number M of at least one overlapping RO of the at least one second RO, determining the at least one second SSB index to be the same as the at least one first SSB index based on a same mapping that is applied for the at least one second RO or the at least one first RO.

3. The terminal device of claim 1, wherein the terminal device is caused to determine the at least one second SSB index by:based on a determination that a number N of at least one overlapping RO of the at least one first RO is greater than a number M of at least one overlapping RO of the at leastone second RO, determining the at least one second SSB index to be the same as the first or last M of the at least one first SSB index as counted in an order of frequency indices based on a same mapping that is applied for the at least one second RO or the first or last M of the at least one first RO as counted in an order of frequency indices.

4. The terminal device of claim 1, wherein the terminal device is caused to determine the at least one second SSB index by:based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining the first or last N of the at least one second SSB index as counted in an order of frequency indices to be the same as the at least one first SSB index based on a same mapping that is applied for the first or last N of the at least one second RO as counted in an order of frequency indices or the at least one first RO.

5. The terminal device of claim 1, wherein the terminal device is caused to determine the at least one second SSB index by:based on a determination that a number N of at least one overlapping RO of the at least one first RO is smaller than a number M of at least one overlapping RO of the at least one second RO, determining one or more groups of N SSB indexes among the at least one second SSB index based on a same mapping that is applied for the group of N SSB indexes of the at least one second RO as counted in an order of frequency indices or the at least one first RO, wherein the group of N SSB indexes as counted in an order of frequency indices is the same as the at least one first SSB index, and N is greater than or equal to 1.

6. The terminal device of any of claims 1-5, wherein the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration.

7. The terminal device of claim 6, wherein the terminal device is caused to determine the at least one third SSB index by:for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed across SBFD ROs and UL ROs configured by the second RACH configuration jointly.

8. The terminal device of claim 6, wherein the terminal device is caused to determine the at least one third SSB index by:for the second set of ROs, determining the at least one third SSB index based on the second mapping that is performed for SBFD ROs and UL ROs configured by the second RACH configuration separately.

9. The terminal device of any of claims 6-8, wherein the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

10. The terminal device of any of claims 1-9, wherein the second ROs at least comprise a RO set including a group of consecutive ROs, and the RO set has a size in number of ROs that is equal to a number of configured SSBs, and wherein the RO set covers indexes of the configured SSBs.

11. The terminal device of claim 10, wherein the RO set at least comprises the at least one second RO and at least one further RO among the second set of ROs.

12. The terminal device of any of claims 1-11, wherein the terminal device is further caused to:transmit a physical random access channel (PRACH) preamble on at least one of the second ROs with the at least one second SSB index and the at least one third SSB index.

13. A network device comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to:transmit, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping ofsynchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; andreceive, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

14. The network device of claim 13, wherein the first ROs at least comprise non subband non-overlapping full duplex (non-SBFD) uplink (UL) ROs, and the second ROs at least comprise SBFD ROs and UL ROs configured by the second RACH configuration.

15. The network device of claim 14, wherein the SBFD ROs further comprise SBFD long length (LL) ROs that cross from a SBFD slot to a UL slot.

16. The network device of any of claims 13-15, wherein the second ROs at least comprise a RO set including a group of consecutive ROs, and the RO set has a size in number of ROs that is equal to a number of configured SSBs, and wherein the RO set covers indexes of the configured SSBs.

17. A method comprising:receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs;determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration;determining, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO; anddetermining, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

18. A method comprising:transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; andreceiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.

19. An apparatus comprising:means for receiving a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs) to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs;means for determining a first set of ROs among second ROs configured by the second RACH configuration, wherein the first set of ROs overlap or partly overlap in time with first ROs configured by the first RACH configuration;means for determining, for at least one second RO among the first set of ROs, at least one second SSB index for the second mapping, wherein the at least one second SSB index is associated with at least one first SSB index of at least one first RO that overlaps or partly overlaps in time with the at least one second RO; andmeans for determining, for a second set of ROs among the second ROs, at least one third SSB index for the second mapping, wherein the second set of ROs do not overlap in time with the first ROs.

20. An apparatus comprising:means for transmitting, to a terminal device, a first random access channel (RACH) configuration and a second RACH configuration, wherein the first RACH configuration comprises first information related to a first mapping of synchronization signal blocks (SSBs)5 to first RACH occasions (ROs), and the second RACH configuration comprises second information related to a second mapping of SSBs to second ROs; andmeans for receiving, from the terminal device, a physical random access channel (PRACH) preamble on at least one of the second ROs with at least one SSB index.10 21. A computer readable medium comprising program instructions for causing anapparatus to perform at least method of any of claims 17-18.

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