A method of random-access procedure in cellular networks introduction

Abstract

Methods for communicating in a network enabled with a sub-band full duplexing (SBFD) is disclosed. The method includes receiving at least one TDD configuration, at least one random access (RACH) configuration, and at least one SBFD configuration, where the at least one TDD configuration configures at least onetime resource as at least one of a downlink (DL) time resource, an uplink (UL) time resource, and a flexible (F) time resource. Further, the at least one SBFD configuration configures at least one uplink sub-band, at least one downlink sub band and at least one SBFD time resource. Further, the at least one RACH configuration configures a plurality of RACH occasions (ROs). Further, the method includes receiving active SSB indices within an SSB burst. Further, the method includes mapping at least one valid RO from the plurality of ROs to the active SSB indices. The at least one valid RO is based on the at least one TDD configuration, the at least one SBFD configuration, and a pre-defined set of validity conditions.

Description

A METHOD OF RANDOM-ACCESS PROCEDURE IN CELLULAR NETWORKS INTRODUCTIONFIELD OF INVENTION

[0001] The present disclosure generally relates to wireless communication, and specifically relates to method of random-access procedure in cellular networks introduction.BACKGROUND

[0002] The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology.

[0003] Existing wireless communication systems or networks generally operate on technologies such as 5G-NR. The 5G-NR technology is designed based on TDD (Time Division Duplexing) technique, where a carrier can be configured for either DL (Downlink) or UL (Uplink) operations at a time. Such a technique uses time slots to separate the transmission and reception of signals on a single frequency channel, and hence, does not permit simultaneous performance of UL and DL operations. Such a disadvantage of existing technologies like 5G-NR is overcome based on the implementation of SBFD (Sub-band Full Duplexing) operation-based communication, which involves a node which can simultaneously perform DL and UL operations in different sub-bands within the same carrier frequency.

[0004] A sub-band is a set of frequency resources within the carrier. The sub-bands of the carrier frequency are used for UL and DL operations may be either on of fully overlapping, partially overlapping, or non-overlapping. In SBFD, sub-bands can be configured within the carrier and different set of operation can be configured within the sub-band. For instance, a UL sub-band can be configured within a DL carrier. Further, the SBFD operation can be enabled for a set of time resources, hereinafter referred to as SBFD active time resources, in which the sub-band is active. The SBFD active time resource can be contiguous or non-contiguous. The time resource granularity can be at symbol level, at slot level or resource type within a slot.

[0005] Despite the advantages of simultaneous UL and DL operations in a single carrier frequency, enabling of SBFD operations in a network may create several conflicts in the network system. Furthermore, enabling of SBFD operations may also create unnecessary transmission and / or monitoring at the nodes of the network. For instance, a UE (User Equipment) may be configured to receive signals in certain RBs (Resource Blocks) in a symbol of a carrier frequency. Thereby, the UE of a wireless communication network may keep monitoring the scheduled resources to receive a DL signal. However, a corresponding BS (Base Station) in SBFD operation mode does not perform DL operations in the RBs. Hence, the UE performs unnecessary monitoring in such an instance.

[0006] In addition to the unnecessary monitoring caused, enabling of SBFD operation in such an instance may create additional interference in the wireless communication network and impact various measurements carried out therein. The UE measures various channel and interference parameters in certain time and frequency resources and report it to the BS. The measurement is assumed to be valid for certain time duration, and one or more parameters for communication in the time duration may be determined by the BS based on the measurement report. However, the additional interference created by enabling of SBFD operation causes variation in channel and interference measurements.

[0007] Therefore, separate measurement of channel and interference parameters is needed for both SBFD active time resources and SBFD inactive time resources, where SBFD inactive time resources refers to a set of time resources corresponding to which SBFD operations are not enabled. Therefore, there arise a need for a method of transmission and reception of channels or signals in a communication network enabled with SBFD by overcoming drawbacks such as conflicts and interference arising due to SBFD operation.

[0008] In addition, Initial Access procedure is a sequence of processes by which user equipment (UE) establishes a connection with the base station (BS) and the network. The procedure enables UE to acquire downlink (DL) and uplink (UL) synchronization and obtain essential information (a.k.a system information) to establish and maintain connection with network. The synchronization signal block (SSB) is a periodic message broadcasted by the BS to enable the UEs to acquire DL synchronization and to convey first set of system information to the UE. The UE, when needed, searches for SSB transmitted in a predefined time and frequency locations. The SSB comprises of primary synchronization signal (PSS), secondary synchronization signal(SSS) and physical broadcast channel (PBCH) comprising of the master information block (MIB). The PSS and SSS signals are used by the UE to obtain the cell identity, obtain the frame boundary and also can be used to measure information about the channel, whereas the MIB is used by the UE to obtain crucial initial broadcast information like the frame information, the scheduling information for control information, etc.

[0009] The BS broadcasts control information within the scheduled set of resources (a.k.a, CORESETO) and it provides scheduling information for system information block 1 (SIB1), which provides essential information about the cell and necessary configurations to perform various operations to latch on to the cell. E.g., information about the set of SSB associated with the cell, information about other system information blocks transmitted in the cell, configuration to perform random access channel (RACH) procedure, the DL / UL transmission pattern of the cell, etc. RACH procedure is an essential part of wireless communication systems, and it plays a significant role in acquiring UL synchronization with the network, obtain specified ID for the radio access communication, etc. The RACH procedure is the first point of contact or the front door for the UE to access the network when it is powered on or after a period of inactivity. Further, the UE initiate the RACH procedure for beam failure recovery (BFR), to demand other system information blocks, handover, etc.

[0010] The fifth-generation (5G) new radio (NR) technology is designed as time division duplex (TDD) system, where at a particular time instant a node performs either DL or UL operation using a carrier frequency. Therefore, in NR, a carrier can be configured for either DL or UL operations at a time. In sub band full duplexing (SBFD) communication, a node can simultaneously perform DL and UL operation in different sub-bands within the same carrier frequency. Therefore, in SBFD, sub-bands can be configured within the carrier and DL operation can be performed in a set of sub-bands and UL operation can be performed in a different set of sub-bands. E.g., DL and UL sub-bands can be defined with a carrier configured conventionally for DL operation and a node can simultaneously perform DL operation using the resources in DL-SB and UL operation using the resources in UL-SB. The sub-bands for DL and UL operations can be of fully overlapping, partially overlapping or non-overlapping. One of the major drawbacks of the SBFD operation is self-interference (SI) created by simultaneous transmission and reception from the same or adjacent sub-band in a node. In case of SBFD with non-overlapping sub-bands, guard bands can be used between the DL and UL sub-bands to minimize the impact of SI from theadjacent sub-bands, whereas in case of partial and fully overlapping sub-bands additional interference cancellation mechanisms are needed to handle SI from the same sub-band as well.

[0011] Thus, there is a need for configurations required to configure RACH occasions (RO) in an SBFD resources, the behaviour of various nodes in the network towards the new scenarios arising due to SBFD (E.g., BS and UE behaviour for a legacy RACH occasion overlapping with SBFD resources), the SSB to RACH mapping procedure / methods in the presence of SBFD, the coexistence of a UE aware of SBFD scenario and a legacy UE, etc. This invention describes the impact of enabling SBFD in a network on initial access procedure, especially the RACH procedure.OBJECT OF THE INVENTION

[0012] An objective of the present invention is to enable SBFD in a network on initial access procedure, especially the RACH procedure.SUMMARY OF THE INVENTION

[0013] This summary is provided to introduce aspects related to a method of random-access procedure in cellular networks introduction.

[0014] In accordance with an embodiment of the present disclosure, a method for communicating in a network enabled with a sub-band full duplexing (SBFD) is being disclosed. In an embodiment, the method includes receiving, by at least one first node, at least one TDD configuration, at least one random access (RACH) configuration, and at least one SBFD configuration, where the at least one TDD configuration configures at least onetime resource as at least one of a downlink (DL) time resource, an uplink (UL) time resource, and a flexible (F) time resource. Further, the at least one SBFD configuration configures at least one uplink subband, at least one downlink sub band and at least one SBFD time resource. Further, the at least one RACH configuration configures a plurality of RACH occasions (ROs). Further, the method includes receiving, by the at least one first node, active SSB indices within an SSB burst. Further, the method includes mapping, by the at least one first node, at least one valid RO from the plurality of ROs to the active SSB indices. The at least one valid RO is based on the at least one TDD configuration, the at least one SBFD configuration, and a pre-defined set of validity conditions.

[0015] According an aspect of the disclosure, the method further includes receiving a plurality of SSB beams. Further, the method includes determining a reference signal received power (RSRP) value corresponding to the plurality of SSB beams. Further, the method includes comparing the RSRP values with a threshold configured. Further, the method includes selecting an SSB beam with the RSRP value crossing the threshold as a best beam.

[0016] According an aspect of the disclosure, the method further includes transmitting, by the at least one first node, a RACH preamble in a valid RO from the at least one valid RO where the valid RO maps to the SSB beam.

[0017] According an aspect of the disclosure, the at least one SBFD time resource overlapping with the at least one valid RO is treated as one of: a. the UL time resource, and b. a non-SBFD time resource.

[0018] According an aspect of the disclosure, the at least one first node is one of: a. a legacy UE, and b. a SBFD aware UE.

[0019] According an aspect of the disclosure, the at least one SBFD time resource is a subset of the at least one time resource.

[0020] According an aspect of the disclosure, an RO from the plurality of RO that starts from the at least one SBFD time resource and ends in a non-SBFD time resource is the at least one valid RO when at least one of: a. the RO is within frequency resources that are both in the at least one UL sub-band and active UL bandwidth part, b. the RO is configured by at least one second RACH configuration for the at least one SBFD time resource, and c. the at least one first node receives an explicit indication.

[0021] According an aspect of the disclosure, the at least one valid RO one of: a. is within the UL time resource, b. is within frequency resources that are both in the at least one UL sub-band and active UL bandwidth part of the at least one SBFD time resource, and c. is in the frequency resources that are both in the at least one UL sub-band and active UL bandwidth part starting from the at least one SBFD time resource and ends in a non-SBFD time resource.

[0022] According an aspect of the disclosure, the at least one SBFD time resource include the at least one time resource indicated as DL time resource by the at least one TDD configuration.

[0023] According an aspect of the disclosure, an RO starting from the at least one SBFD time resource and ends in a non-SBFD time resource is valid only when the RO is configured by at least one second RACH configuration; and the at least one first node receives an explicit indication.

[0024] According an aspect of the disclosure, the explicit indication indicates whether the configured ROs across the at least one non-SBFD time resource and the at least one SBFD time resource is valid.

[0025] According an aspect of the disclosure, the explicit indication is in the at least one second RACH configuration.

[0026] According an aspect of the disclosure, the at least one second RACH configuration configures random access parameters for the at least one SBFD time resource.

[0027] According an aspect of the disclosure, an RO starting from the at least one SBFD time resource and ends in a non-SBFD time resource comprises: at least one parameter for transmitting a RACH preamble is same in the portion of the RO overlapping with the at least one SBFD time resource and the at least one non-SBFD time resource.

[0028] According an aspect of the disclosure, the at least one parameter comprises at least one of: at least one frequency resource for transmission, and a transmit power.

[0029] According an aspect of the disclosure, the method further comprises receiving, by at least one first node, at least one TDD configuration, at least one random access (RACH) configuration, and at least one SBFD configuration is one of: received contiguously; and received in intervals.

[0030] According an aspect of the disclosure, receiving the at least one RACH configuration comprises at least one of: receiving, by the at least one first node, at least one first RACH configuration, and receiving, by the at least one first node, at least one second RACH configuration.

[0031] According an aspect of the disclosure, the at least one first RACH configuration comprises at least one of: scheduling information of at least one first RO, an at least one first time resource, an at least one first frequency resource, an at least one first frequency offset, a total number of preambles per RO, a number of SSBs sharing a RO, a number of contention based preambles per SSB per RO, a number of ROs multiplexed in frequency domain, and an at least one index from a predefined table.

[0032] According an aspect of the disclosure, the at least one second RACH configuration comprises at least one of scheduling information of at least one second RO, an at least one second time resource an at least one second frequency resource, an at least one second frequency offset, a number of ROs multiplexed in frequency domain, at least one index from a predefined table, at least one offset, at least one scaling factor, a total number of preambles per RO for the at least one SBFD time resource, a number of SSBs sharing a RO for the at least one SBFD time resource, a priority of SSB indices for SSB-RO mapping in the at least one SBFD time resource, at least one SSB index for SSB-RO mapping in the at least one SBFD time resource, a number of contentions based preambles per SSB per RO for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, and at least one number.

[0033] According an aspect of the disclosure, the at least one offset is at least one of frame offset, subframe offset, slot offset, symbol offset and a frequency offset.

[0034] According an aspect of the disclosure, the at least one number is at least one of subframe number, slot number, and symbol number.

[0035] According an aspect of the disclosure, the at least one second RACH configuration configures random access parameters for the at least one SBFD time resource.

[0036] According an aspect of the disclosure, the method further includes receiving the at least one RACH configuration includes receiving at least one frequency offset. The method further includes interpreting the at least one frequency offset as the frequency offset of lowest RO in frequency domain with respective to one of: a lowest frequency resource in the at least one UL sub band, a lowest frequency resource in the UL bandwidth part, and a lowest frequency resource from the frequency resources overlapping with the at least one UL sub band and a UL bandwidth part.

[0037] According an aspect of the disclosure, interpreting is for at least one of: at least one RO in the at least one SBFD time resource, and at least one second RO.

[0038] According an aspect of the disclosure, the at least one valid RO comprises at least one of: at least one first RO, and at least one second RO.

[0039] According an aspect of the disclosure, the at least one first RO is in the at least one time resource configured as one of UL time resource and the F time resource by the at least one TDD configuration.

[0040] According an aspect of the disclosure, the at least one second RO is at least one of: within frequency resource that are both in the active UL bandwidth part and in the at least one UL subband, within the at least one time resource configured as DL time resource by the at least one TDD configuration, and one of: within the at least one SBFD time resource, and across the at least one SBFD time resource and at least one non-SBFD time resource.

[0041] According an aspect of the disclosure, the method further includes at least one of: a. mapping the at least one first RO to the active SSB indices, and b. mapping the at least one second RO to the active SSB indices.

[0042] According an aspect of the disclosure, the method includes the mapping is based on at least one parameter configured by at least one first RACH configuration.

[0043] According an aspect of the disclosure, a. mapping for the at least one first RO is based on at least one parameter configured by at least one first RACH configuration, and b. mapping for the at least one second RO is based on at least one parameter configured by at least one second RACH configuration.

[0044] According an aspect of the disclosure, the method further includes at least one of: a. computing a first RACH association period for the at least one first RO; and b. computing a second RACH association period for the at least one second RO.

[0045] According an aspect of the disclosure, the method further includes a. computing a first RACH association pattern period based on the first RACH association period; and b. computing a second RACH association pattern period based on the second RACH association period.

[0046] According an aspect of the disclosure, the method further includes a. computing effective RACH association period as maximum of the first RACH association period and the second RACH association period; and b. computing effective RACH association pattern period based on the effective RACH association period.

[0047] According an aspect of the disclosure, computing the first RACH association period further includes a. mapping the at least one second RO within the first RACH association period to the active SSB indices.

[0048] According an aspect of the disclosure, mapping is one of: a. dividing the at least one second RO within the first RACH association period equally among the active SSB indices, b. based on at least one parameter configured by at least one first RACH configuration, and c. based on at least one parameter configured by at least one second RACH configuration.

[0049] According an aspect of the disclosure, the method further includes at least one of: a. transmitting a first RACH preamble in a first RO from the at least one first RO and b. transmitting a second RACH preamble in a second RO from the at least one second RO.

[0050] According an aspect of the disclosure, the second RACH preamble is for the at least one SBFD time resource and is one of: a. predefined; and b. received by the at least one first node.

[0051] According an aspect of the disclosure, the at least one RACH preamble for the at least one SBFD time resource comprises at least one of: a. at least one root sequence, b. at least one cyclic shift, c. reusing non-RACH preamble, and d. at least one preamble from contention free preamble.

[0052] According an aspect of the disclosure, the at least one SBFD time resource is contiguous.

[0053] According to an aspect of the disclosure, the first node may be a user equipment (UE).

[0054] In accordance with another embodiment of the present disclosure, a method for communicating in a network enabled with a sub-band full duplexing (SBFD) is being disclosed. The method further include transmitting, by at least one second node, a plurality of SSB beams, at least one TDD configuration, at least one random access (RACH) configuration, and at least one SBFD configuration. The at least one TDD configuration configures at least one time resource as at least one of a downlink (DL) time resource, an uplink (UL) time resource, and a flexible (F) time resource. The at least one SBFD configuration configures at least one uplink sub-band, at least one downlink sub band and at least one SBFD time resource. The at least one RACH configuration configures a plurality of RACH occasions (ROs). The method further includes receiving, by the at least one second node, from at least one first node a RACH preamble in a valid RO from a plurality of valid ROs the plurality of valid RO is based on: the at least one TDD configuration, the at least one SBFD configuration, and a pre-defined set of validity conditions. The method further includes identifying, by the at least one second node, best SSB beam for the at least one first node from the plurality of SSB beams based on the RACH preamble and the valid RO.

[0055] According an aspect of the disclosure, the transmitting further includes at least one of: transmitting active SSB indices within an SSB burst, configuring minimum reference signal received power (RSRP) value that an SSB beam should have, transmitting at least one frequency offset, transmitting an indication to perform a random access procedure using one of at least one first RO and at least one second RO, transmitting at least one first RACH configuration, transmitting at least one second RACH configuration, transmitting first set of RACH preamble, transmitting a second set of RACH preamble for the at least one SBFD time resource, and transmitting an explicit indication indicating whether an RO from the plurality of ROs starting from the at least one SBFD time resource and ending in a non-SBFD time resource is valid.

[0056] According an aspect of the disclosure, the RO is configured by the at least one second RACH configuration.

[0057] According an aspect of the disclosure, the at least one second RACH configuration configures at least one parameter for the at least one SBFD time resource.

[0058] According an aspect of the disclosure, the method further includes identifying the best SSB beam includes: mapping the plurality of valid ROs to the active SSB indices. The method further includes identifying at least one SSB beam corresponding to the valid RO.

[0059] According an aspect of the disclosure, the method further includes identifying the best SSB beam from the at least one SSB beam based on the RACH preamble and the at least one RACH configuration.

[0060] According an aspect of the disclosure, the at least one SBFD time resource is a subset of the at least one time resource.

[0061] According an aspect of the disclosure, an RO that starts from the at least one SBFD time resource and ends in a non-SBFD time resource is in the plurality of valid ROs when at least one of: a. the RO is within the frequency resources that are both in the at least one UL sub-band and active UL bandwidth part, b. the RO is configured by the at least one second RACH configuration for the at least one SBFD time resource; and c. the at least one first node receives an explicit indication.

[0062] According an aspect of the disclosure, an RO from the plurality of valid ROs one of: is within the UL time resource, is within the frequency resources that are both in the at least one UL sub-band and active UL bandwidth part of the at least one SBFD time resource, and is in the frequency resources that are both in the at least one UL sub-band and active UL bandwidth part starting from the at least one SBFD time resource and ends in a non-SBFD time resource.

[0063] According an aspect of the disclosure, the at least one SBFD time resource include the at least one time resource indicated as DL time resource by the at least one TDD configuration.

[0064] According an aspect of the disclosure, the RO starting from the at least one SBFD time resource and ends in a non-SBFD time resource is valid only when a. the RO is configured by at least one second RACH configuration for the at least one SBFD time resource, and b. the at least one second node provides an explicit indication.

[0065] According an aspect of the disclosure, the RO starting from the at least one SBFD time resource and ends in a non-SBFD time resource comprises: at least one parameter for receivingthe RACH preamble is same in the portion of the RO overlapping with the at least one SBFD time resource and the at least one non-SBFD time resource.

[0066] According an aspect of the disclosure, the at least one parameter comprises at least one of: at least one frequency resource for reception, and a transmit power.

[0067] According an aspect of the disclosure, transmitting the plurality of SSB beams, the at least one TDD configuration, the at least one RACH configuration, and the at least one SBFD configuration is one of: contiguously, and in intervals.

[0068] According an aspect of the disclosure, the transmitting the at least one first RACH configuration includes transmitting at least one of: scheduling information of at least one first RO, an at least one first time resource, an at least one first frequency resource, an at least one first frequency offset, a total number of preambles per RO, a number of SSBs sharing a RO, a number of contention based preambles per SSB per RO, a number of ROs multiplexed in frequency domain, and an at least one index from a predefined table.

[0069] According an aspect of the disclosure, transmitting the at least one second RACH configuration include transmitting at least one of: scheduling information of at least one second RO, an at least one second time resource, an at least one second frequency resource, an at least one second frequency offset, a number of ROs multiplexed in frequency domain, at least one index from a predefined table, at least one offset, at least one scaling factor, a total number of preambles per RO for the at least one SBFD time resource, a number of SSBs sharing a RO for the at least one SBFD time resource, a priority of SSB indices for SSB-RO mapping in the at least one SBFD time resource, at least one SSB index for SSB-RO mapping in the at least one SBFD time resource, a number of contentions based preambles per SSB per RO for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, and at least one number.

[0070] According an aspect of the disclosure, the at least one offset is at least one of frame offset, subframe offset, slot offset, symbol offset and a frequency offset.

[0071] According an aspect of the disclosure, the at least one number is at least one of subframe number, slot number, and symbol number.

[0072] According an aspect of the disclosure, the at least one frequency offset is the frequency offset of lowest RO in frequency domain with respective to one of: a lowest frequency resource in the UL sub band, a lowest frequency resource in the UL bandwidth part, and a lowest frequency resource from the frequency resources overlapping with the UL sub band and UL bandwidth part.

[0073] According an aspect of the disclosure, the at least one frequency offset is applicable for at least one of: at least one RO in the at least one SBFD time resource, and at least one second RO.

[0074] According an aspect of the disclosure, the plurality of ROs includes at least one first RO, and at least one second RO.

[0075] According an aspect of the disclosure, the at least one first RO is in the at least one time resource configured as one of the UL time resource and the F time resource by the at least one TDD configuration.

[0076] According an aspect of the disclosure, the at least one second RO is at least one of: within frequency resource that are both in the active UL bandwidth part and in the UL sub -band, within the at least one time resource configured as DL time resource by the at least one TDD configuration, and one of: within the at least one SBFD time resource, and across the at least one SBFD time resource and at least one non-SBFD time resource.

[0077] According an aspect of the disclosure, the method further includes at least one of: a. mapping the at least one first RO to the active SSB indices, and b. mapping the at least one second RO to the active SSB indices.

[0078] According an aspect of the disclosure, mapping is based on at least one parameter configured by at least one first RACH configuration.

[0079] According an aspect of the disclosure, mapping the at least one first RO is based on at least one parameter configured by at least one first RACH configuration, and b. mapping the at least one second RO is based on at least one parameter configured by at least one second RACH configuration.

[0080] According an aspect of the disclosure, the method further includes at least one of: a. computing a first RACH association period for the at least one first RO; and b. computing a second RACH association period for the at least one second RO.

[0081] According an aspect of the disclosure, the method further includes a. computing a first RACH association pattern period based on the first RACH association period, and b. computing a second RACH association pattern period based on the second RACH association period.

[0082] According an aspect of the disclosure, the method further includes a. computing effective RACH association period as maximum of the first RACH association period and the second RACH association period, and b. computing effective RACH association pattern period based on the effective RACH association period.

[0083] According an aspect of the disclosure, the method further includes computing the first RACH association period further comprises: a. mapping the at least one second RO within the first RACH association period to the active SSB indices.

[0084] According an aspect of the disclosure, the mapping is one of: a. dividing the at least one second RO within the first RACH association period equally among the active SSB indices, b. based on at least one parameter configured by at least one first RACH configuration, and c. based on at least one parameter configured by at least one second RACH configuration.

[0085] According an aspect of the disclosure, transmitting the second set of RACH preamble for the at least one SBFD time resource includes transmitting at least one of: a. at least one root sequence, b. at least one cyclic shift, c. index of at least one non-RACH preamble, and d. index of at least one preamble from contention free preamble.

[0086] According an aspect of the disclosure, the identifying the best SSB beam includes: identifying at least one of type of SSB-RO mapping and type of the at least one first node.

[0087] According an aspect of the disclosure, the type of the at least one first node includes: a. legacy UE, and b. SBFD aware UE.

[0088] According an aspect of the disclosure, type of the SSB-RO mapping includes one of: a. SSB-RO mapping considering only at least one first RO, b. SSB-RO mapping considering onlyat least one second RO, and c. SSB-RO mapping considering both at least one first RO and at least one second RO.

[0089] According an aspect of the disclosure, the identifying includes at least one of: identifying the at least one first node as SBFD aware UE, identifying the SSB-RO mapping include one of: at least one second RO only, and both at least one first RO and at least one second RO when at least one of the RACH preamble is from a second set of RACH preamble and the valid RO is from the at least one second RO.

[0090] According an aspect of the disclosure, a. the second set of RACH preamble is configured for the at least one SBFD time resource, and b. the at least one second RO is configured for the at least one SBFD time resource.

[0091] According an aspect of the disclosure, the at least one SBFD time resource is contiguous.

[0092] According an aspect of the disclosure, the at least one SBFD time resource overlapping with at least one valid RO from the plurality of valid RO is treated as one of: a. the UE time resource, and b. a non-SBFD time resource.

[0093] According an aspect of the disclosure, the at least second node may be a base station.

[0094] Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0095] The accompanying drawings constitute a part of the description and are used to provide a further understanding of the present invention.

[0096] Fig. 1 illustrates an example environment of a wireless communication network, according to an embodiment of the present disclosure.

[0097] Fig. 2 illustrates time domain allocation of RO, according to an embodiment of the present disclosure.

[0098] Fig. 3 illustrates the RACH association period and the RACH association pattern period, according to an embodiment of the present disclosure.

[0099] Fig. 4 illustrates a SBFD active time resources within a resource grid of a carrier frequency, in accordance with an embodiment of the present invention

[0100] Fig. 5 illustrates an exemplary overlap of a BWP of a UE with a sub-band for SBFD operation, in accordance with an embodiment of the present invention.

[0101] Fig. 6a illustrates an exemplary TDD pattern configured using legacy method in NR, in accordance with an embodiment of the present invention.

[0102] Fig. 6b illustrates an exemplary TDD configuration after SBFD configuration, in accordance with an embodiment of the present invention.

[0103] Fig. 7 illustrates possible scenarios for ROs in the presence of SBFD configuration, in accordance with an embodiment of the present invention.

[0104] Fig. 8 illustrates an exemplary SSB-RO mapping and RACH timings in the presence of SBFD, in accordance with an embodiment of the present invention

[0105] Fig. 9 illustrates a flowchart of steps of the proposed method executed by a UE, in accordance with an embodiment of the present invention.

[0106] Fig. 10 illustrates a flowchart of steps of the proposed method executed by a BS, in accordance with an embodiment of the present invention.

[0107] Fig. 11 illustrates a general block diagram of the node, according to an embodiment of the present disclosure.

[0108] A more complete understanding of the present invention and its embodiments thereof may be acquired by referring to the following description and the accompanying drawings.DESCRIPTION OF THE INVENTION

[0001] Exemplary embodiments now will be described with reference to the accompanying drawings. The disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. The terminology used in the detailed description of the particular exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting. In the drawings, like numbers refer to like elements.

[0002] It is to be noted, however, that the reference numerals used herein illustrate only typical embodiments of the present subject matter, and are therefore, not to be considered for limiting its scope, for the subject matter may admit to other equally effective embodiments.

[0003] The specification may refer to “an”, “another”, “one” or “some” embodiment s) in several locations.

[0004] This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.

[0005] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes”, “comprises”, “including” and / or “comprising” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. Furthermore, “connected” or “coupled” as used herein may include operatively connected or coupled. As used herein, the term “and / or” includes any and all combinations and arrangements of one or more of the associated listed items.

[0006] The phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” and the like generally mean that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure, andmay be included in more than one embodiment of the present disclosure (importantly, such phrases do not necessarily refer to the same embodiment).

[0007] The word “example” or “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

[0008] Unless otherwise defined, all terms (including 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 pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0009] Although various arrow types and line types may be employed in the flowchart and / or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and / or flowchart diagrams, and combinations of blocks in the block diagrams and / or flowchart diagrams, can be implemented by special purpose hardwarebased systems that perform the specified functions or acts, or combinations of special purpose hardware and code.

[0010] As used herein, the terms “user equipment” (UE) and “base station” are not intended to be specific or otherwise limited to any particular radio access technology (RAT), unless otherwise noted. In general, a UE may be any wireless communication device (e.g., a mobile phone, router, tablet computer, laptop computer, tracking device, wearable (e.g., smartwatch, glasses, augmented reality (AR) / virtual reality (VR) headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.), Internet of Things (loT) device, etc.) used by a user to communicate over a wireless communications network. A UE may be mobile or may (e.g., at certain times) be stationary, and may communicate with a radio access network (RAN). Generally, UEs can communicate with a core network via a RAN, and through the core network the UEs can be connected with external networks such as the Internet and with other UEs. Of course, other mechanisms of connecting tothe core network and / or the Internet are also possible for the UEs, such as over wired access networks, wireless local area network (WLAN) networks (e.g., based on IEEE 802.11, etc.) and so on.

[0011] A base station may operate according to one of several RATs in communication with UEs depending on the network in which it is deployed, and maybe alternatively referred to as an access point (AP), a network node, a NodeB, an evolved NodeB (eNB), a New Radio (NR) Node B (also referred to as a gNB or gNodeB), etc.

[0012] The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.

[0013] Fig. 1 illustrates an example environment of a wireless communication network, according to an embodiment of the present disclosure. The wireless communication network 400 includes at least one UE 401 in communication with one or more base stations (BSs) i.e. 403-1, 403-2, 403-3, 403-4, and the like. The base station(s) may be collectively referred with label 403.

[0014] The RACH procedure in 5G NR is broadly classified into two types: contention-based RACH procedure (CB-RACH) and contention free RACH procedure (CF-RACH). In CB-RACH, the UE randomly selects a random-access preamble from a pool of preambles configured and transmit the selected preamble to the BS in certain time frequency resources. The pool of preambles and the time frequency resources are determined by the UE based on RACH configuration provided in SIB1 and the measurement of SSBs by the UE. The time frequency resource for transmitting RACH preamble is also known as RACH occasions (RO). The pool of preambles is common for a set of UEs and can lead to contention if multiple UEs select the same preamble from the pool and transmit in same RO. Hence the procedure is termed CB-RACH. Using the RO in which the physical random-access channel (PRACH) is received, the BS determines information about the SSB beam selected by the UE, the propagation delay with the UE, timing misalignment at the UE, etc. and sends a response called MSG2, a.k.a random-access response (RAR). The MSG2 consists of several critical information, such as the time advance (TA) command for timing adjustment, the RAPID (random access preamble ID) matching the preamble sent by the UE, an initial UL grant for the UE, a temporary radio network identifier called random access radio network temporary identifier (RA-RNTI) to the UE, etc.

[0015] All the UEs that have transmitted a preamble will wait for MSG2 in a preconfigured set of resources, where the configuration for RAR window is provided to UE in SIB 1. After receiving MSG2 and performing the required timing adjustment, the UE transmits MSG3 using the UL grant received in MSG2. The MSG3 is transmitted after applying TA and in physical UL shared channel (PUSCH). The MSG3 contains the UE identity, C-RNTI if the UE was previously connected in the network or identity provided by the core network. In the case of contention, multiple UE transmit MSG3 in same resource. However, the BS decode only one MSG3 and sends MSG4 for contention resolution along with the identity of the UE contained in decoded MSG3. The UE compare identity received in MSG4 with identity transmitted in MSG3 and report RACH success only when a match is found. E.g., if UE has transmitted C-RNTI in MSG3 and received MSG4 on control channel addressed by C-RNTI. Since C-RNTI is unique, only intended UE will decode MSG4.

[0016] In NR, the SSB is transmitted in multiple beams known as SSB burst. In frequency range 1 (FR1), the SSB burst can have a maximum of 8 beams, whereas in frequency range 2 (FR2), the SSB burst can have up to 64 beams.

[0017] The actual SSBs transmitted in an SSB burst is indicated to the UE using following information elements (IBs) as discussed herein. One of the information elements is ssb- Positionslnburst which indicates index of the transmitted SSB in an SSB burst and has the following fields: groupPresence: In NR, the SSBs can be grouped into 8 groups and each group can have 8 SSBs each. This bit string of length 8 indicates which groups of SSBs are present out of 8 groups. Value 0 in the bitmap indicates that the corresponding SS / PBCH group is not present while value 1 indicates that the corresponding SS / PBCH group is present. This field is present only in the case of FR2, where the total number of SSBs is larger than 8. inOneGroup: This bit string of length 8 indicates which SSBs are present within a group. Value 0 in the bitmap indicates that the corresponding SS / PBCH block is not transmitted while value 1 indicates that the corresponding SS / PBCH block is transmitted. Further, the first / leftmost bit corresponds to SS / PBCH block index 0, the second bit corresponds to SS / PBCH block index 1, and so on.

[0018] The UE measure multiple beams in the SSB burst, and identifies the best beam (the beam for which the value of the measured parameter crosses the threshold, which is configured) based on the measurement. Further, the UE determines the RACH preamble and RO corresponding to the best beam. The configuration to select the best beam, determine RO and map SSB with the RO are provided to UE in SIB1, using IE RACH-ConfigCommon using the following fields.

[0019] The field rsrp-thresholdSSB configures the minimum reference signal received power (RSRP) value that an SSB beam should have. The UE determine RSRP value corresponding to multiple SSB beams received, compare the RSRP values with the threshold configured and select the SSB beam with RSRP value crossing threshold as the best beam. If none of the SSB beam crosses the threshold configured, then the UE select randomly one beam from the SSB burst.

[0020] The field totalNumberOfRA-Preambles indicates the total number of preambles per PRACH occasion which are available for both the CB-RACH and CF-RACH. In NR, a maximum of 64 preambles can be configured per RO and these preambles are divided into three groups: for CB-RACH, for CF-RACH and for other purpose. The other purpose include preamble for requesting other system information blocks. E.g., if totalNumberOfRA-Preambles=5Q then out of 64 preambles, 50 are available for CB-RACH and CF-RACH.

[0021] The field ssb-perRACH-OccasionAndCB-PreamblesPerSSB conveys two parameters wherein the first part indicates the number of SSBs sharing a RO. E.g., value of oneEighth corresponds to one SSB associated with 8 RACH occasions, value Four corresponds to 4 SSBs sharing a RACH occasion and so on. The second part indicates the number of contention-based preambles per SSB per valid RACH occasion. E.g. value n4 corresponds to 4 contention-based preambles per SSB in a RO, value n8 corresponds to 8 contention based preambles per SSB in a RO, and so on.

[0022] Using the values indicated by totalNumberOfRA-Preambles and ssb-perRACH- OccasionAndCB-PreamblesPerSSB the number of CB preambles per RO and number of CF preambles can be computed. E.g., if ssb-perRACH-Occasion = 1 / 2 and CB-PreamblesPerSSB = 40 then each SSB beam span across 2 RO and 40 CB preambles are available to an SSB beam in a valid RO. Therefore, a total of 80 contention-based preambles available to each SSB beam. Further, in a RO the difference between value indicated by totalNumberOfRA-Preambles and number of preambles available for CB-RACH gives the number of preambles available for CF-RACH. E.g., if totalNumberOfRA-Preambles=5Q and 40 preambles are for CB-RACH then remaining 10 preambles for CF-RACH. In another e.g., if totalNumberOfRA-Preambles=5Q and ssb-perRACH-OccasionAndCB-PreamblesPer SSB = (2, n24) then, a total of 50 preambles are available for RACH, two SSBs will share a RO and n24 implies 24 preambles / SSB in a RO. Therefore, total number of CB preambles in a RO = 2 SSB / ROx24 preambles / SSB=48 Preambles. Remaining 2 preambles, out of total 50, are for contention free RACH. In general, the total number of CB preambles per RO is given byCBpreambles / RO = CBpreambles / SSB). Max l, SSB / RO)

[0023] The field of prach-Configurationindex is used to indicate the time domain position of the ROs. The indicated value points to a row in one of predefined look up tables. The table is selected based on the frequency range and paring of spectrum. The indicated row in the selected table provides information such as preamble format to use (e.g., short or long preamble), the frame in which RO is present (i.e., even frame or odd frame), subframe / slots in which RO is present, the number of slots having RO in a subframe, number of RO within each slot, starting symbol of RO and duration of RO.

[0024] The time domain allocation of RO is illustrated in Fig. 2 of the present invention. For example, prach-Configuration / index indicates the following values: x = 2, y = 1, subframe number = (4, 9), PRACH slots within subframe = 2, PRACH occasion within PRACH slot = 3, PRACH duration = 4, and starting symbol = 0. System frame number satisfying condition, n_SFN mod x = y, only has RO. Applying x and y in formula only odd frames will have ROs. Field subframe number = (4, 9) implies subframes 4 and 9 within odd frame has RO. Further, each subframe has 2 slots, each slot has 3 ROs starting from symbol 0 and each RO is of duration 4 symbols.

[0025] The field of msgl-FDM specifies the number of ROs which are multiplexed in the frequency domain. E.g., msgl-FDM=^ imply 4 ROs are multiplexed in the frequency domain.

[0026] The field of msgl -FrequencyStart indicates the frequency domain position of the ROs. The field indicate the position of the lowest PRB belonging to the first RO. The indication is using a frequency offset with respect to starting PRB of the channel bandwidth. The number of PRBs in a RO depend on sub carrier spacing (SCS) of PUSCH, SCS of PRACH and length of the RACH preamble. For example, for RACH SCS = 15 KHz and short preamble of 139 subcarriers, thepreamble occupied BW = 2085 KHz. For SCS of PUSCH = 30 KHz, number of PRBs occupied by preamble = 2085 KHz / (12x30 KHz) = 6 PRBs.

[0027] The NR RACH preamble sequence is based on Zadoff Chu sequence. The reason for choosing Zadoff Chu is due to its favourable properties, including constant amplitude before and after DFT operation, zero cyclic autocorrelation and low cross correlation. The configuration for generating RACH preamble in the ROs is given by RACH-ConfigCommon using the following fields as discussed below.

[0028] The field prach-RootSequencelndex configures the length of the preamble (L=839 or 139 or 571 or 1151) and the logical index of the root sequence to the UE. The value of L depends on the coverage of the cell. For example, L=139 for smaller coverage and L=839 for large coverage. The range of the logical index depends on the value of L (0 to L-2). Mapping from logical index to sequence number is predefined in standards.

[0029] The concept of restricted set is used to mitigate the impact of Doppler frequency offset in the case of high mobility scenario. The restricted set configures higher value of cyclic shift for generating the RACH preamble from the root sequence, there by skipping some of the possible options for RACH preamble. Therefore, the field restrictedSetConfig increases the separation between preambles and hence more resistance to frequency offsets. For FR1 (frequency <6GHz), there are three types of restricted sets: Unrestricted set, restricted set type A and restricted set type B. Unrestricted sets are intended to use with frequency offset which do not exceed half of SCS. Restricted sets type A are intended to use with frequency offset which do not exceed the SCS. Restricted sets type B are intended to use with frequency offset which do not exceed twice of the SCS. For FR2, there are no restricted sets because FR2 uses short preamble formats and restricted sets are applicable for long preamble format only.

[0030] The field zeroCorrelationZoneConfig configures the value of cyclic shift, to apply on a root sequence, for the restricted set configured by restrictedSetConfig. The value of cyclic shift corresponding to the value indicated by zeroCorrelationZoneConfig for each restricted set type is predefined in the standard. In general, the cyclic shift increases with high value of zeroCorrelationZoneConfig. Similarly, for the same value of zeroCorrelationZoneConfig, the value of cyclic shift is smaller for unrestricted set and increases for restricted sets type A, followed by restricted sets type B.

[0031] The UE generates the RACH preamble by applying a cyclic shift to the root sequence, indicated by prach-RootSequencelndex, where the cyclic shift is a function of PRACH preamble index, prach-RootSequencelndex, zeroCorrelationZoneConfig and restrictedSetConfig. The UE generate 64 preambles in each RO. If 64 preambles cannot be generated from the root sequence, indicated, then the UE increment the sequence number to obtain new root sequence and cyclic shift is applied to the new root sequence until getting 64 preambles. Same set of root sequences and cyclic shift apply for all ROs in a cell. Therefore, the 64 preambles remain the same for all ROs across time and frequency domains in a cell. Neighbouring cell will be assigned a different root sequence.

[0032] Once the UE has information about the SSBs present in a burst, the set of RACH preambles and information about the ROs, the next step is to identify the RO corresponding to the SSB beams measured and determine the RO corresponding to the selected SSB beam. The SS / PBCH block indices provided by ssb-PositionsInBurst are mapped to valid ROs in the following order. First, in increasing order of preamble indices within a single RO; second, in increasing order of frequency resource indices for frequency multiplexed ROs; third, in increasing order of time resource indices for time multiplexed ROs within a RACH slot; and fourth, in increasing order of indexes for PRACH slots.

[0033] In another embodiment, regarding timings associated with RACH process, different timing relations has been defined in NR for RACH configuration and associated procedures. The time duration for which time domain configuration provided for RACH, in prach- Configuration / index, get repeated is known as the RACH configuration period. For example, if x and y provided in prach-Configurationindex is 2 and 1, respectively, then only odd system frames have ROs. Therefore, the RACH configuration period is 20 ms.

[0034] The RACH association period is the smallest number of RACH configuration period for mapping SS / PBCH block indexes to ROs from a predefined set, such that all SSB indices, provided in ssb-PositionsInburst, are mapped at least once to the PRACH occasions. The possible number of PRACH configuration periods that can be counted in RACH association period is predefined in NR standards and is given in Table 1, below.

[0035] In one example, if there are 32 SSB beams, SSB / RO = 2 and 48 ROs within a 20 ms PRACH configuration period, then a total of 16 ROs are needed to cover all the SSBs. Since a single RACH configuration period has 48 ROs, each SSB can be mapped 3 times within a RACH configuration period. Therefore, RACH association period is 1 in this case.

[0036] In yet another example, if there are 64 SSB beams, 1 SSB / RO and 24 ROs within a 20 ms RACH Configuration Period then, a total of 64 ROs are needed to map all SSBs at least once. Therefore, 3 RACH configuration periods are needed to get the 64 ROs. However, the predefined set of values for association period does not include 3. Therefore, association period is considered as 4 RACH configuration periods, having a total of 96 ROs. Since there are 64 SSB beams, 64 ROs are used by SSB beams, out of 96 ROs, and the remaining 32 are unused.

[0037] The number of ROs in a RACH configuration period varies depending on the configuration of high priority signals and channels. E.g., if a configuration for SSB overlaps with RACH configuration period, then ROs within that period are not counted as valid ROs. Similarly, if at least one symbol of a RO is configured as DL by configuration, then the RO is not considered as valid. Therefore, the number of configuration periods within a RACH association period keeps on varying.

[0038] An association pattern period includes one or more association periods and is determined so that a pattern between ROs and SSB indices repeats at most every 160 msec. The ROs that are not associated with SSB indices after an integer number of association periods, if any, are not used for RACH transmissions. For example, if there are 8 SSB beams and 1 SSB / RO, then association period should have 8 ROs. Further, RACH configuration period is assumed to be 10 ms and SSB periodicity is assumed to be 80 ms. Due to configuration for high priority signals and DL pattern the number of RO varies across RACH configuration period as: no valid RACH occasions are assumed in a frame having SSBs, 8 ROs in an even numbered frame and 6 ROs in an odd numbered frame.

[0039] Fig. 3 of the present invention illustrates the RACH association period and the RACH association pattern period as discussed above. The first RACH association period indicated in blue colour comprises of 4 RACH configuration periods with 20 ROs, where each SSB is mapped twice (8 x 2 = 16 ROs) and the remaining 4 ROs are wasted. The second RACH association period indicated in yellow colour comprises 1 RACH configuration period with 8 ROs, where each SSB is mapped once. The mapping continues in a similar manner. The last association period indicated in red colour comprises 14 ROs and each of 8 SSBs is mapped once (8 x 1 = 8 ROs) and the remaining 6 ROs are wasted. Similarly, the last RACH configuration period in 160 ms window illustrated in grey colour has 6 ROs and it cannot be mapped to 8 SSBs. Therefore, ROs in the last RACH configuration period remain unused.

[0040] Existing method of wireless communication are generally based on technologies such 5G- NR (Fifth generation New Radio) designed based on TDD (Time Division Duplexing) technique. In TDD, a carrier signal may be configured for either of DL or UL operation at a time. The transmission and reception of signals are performed by a node of the communication network in different time slots of a single frequency channel in TDD, which restricts the simultaneous performance of UL and DL operations. SBFD (Sub-band Full Duplexing) operation-based communication is used for overcoming the above-mentioned limitation in existing technologies, wherein a node simultaneously performs DL and UL operations in different sub-bands of the same carrier frequency or same frequency channel.

[0041] In SBFD technique, a sub-band relates to a set of frequency resources within a carrier frequency. The sub-bands used by a node for DL or UL operations may be fully overlapping, partially overlapping, or non-overlapping. In SBFD, a node defines multiple sub-bands within acarrier and simultaneously perform DL operation in DL sub-band and UL operation in UL subband. The SBFD operation can be enabled for a set of time resources, referred as SBFD active time resource in this invention, in which the sub-band is active. The SBFD active time resource can be contiguous or non-contiguous. The time resource granularity can be at symbol level, at slot level or resource type within a slot.

[0042] Fig. 4 illustrates a SBFD active time resources within a resource grid of a carrier frequency, in accordance with an embodiment of the present invention. The resource grid comprises 8 resource blocks (RBs) within a carrier, configured for DL operation using conventional methods. The resource blocks RBI to RB4 are configured as UL sub-band and it is active from symbol 1 to symbol 5. Hence, in symbols 1 to 5, a BS can simultaneously perform a DL transmission to a UE using resource blocks RBO, RB5, RB6 and RB7, and can receive a UL transmission from another UE in resource blocks RB 1 to RB4.

[0043] In cellular network-based wireless communication, a BS may operate using multiple carrier, wherein operation with respect to each carrier may be based on use of a large bandwidth. However, a UE does not have access to all such carriers, or to an entire bandwidth of each carrier. The set of frequency resources for which the UE does have access within a carrier is known as bandwidth part (BWP). A UE can be configured with multiple BWPs, and a subset of the multiple BWPs configured to the UE may be active at a time. Further, separate BWPs can be configured for DL and UL operations performed by the UE. In SBFD operation-based in such a cellular communication network, in certain instances, a BWP configured to a UE may overlap with a subband used for SBFD operation. In such instances, the size of the BWP may vary in SBFD active time resource depending on the nature of overlap with the SBFD sub-band.

[0044] In the context of SBFD, the UEs in the network can be classified into two categories: legacy UEs and SBFD aware UEs. The legacy UEs are unaware about the SBFD operation and parameters of SBFD operation. However, the BS can configure the parameters of SBFD to the SBFD aware UEs, where the parameters are location of sub-bands within a carrier, type of subbands (i.e., DL-SB or UL-SB), size of the sub-band, SBFD active time resource, etc. The configuration of some parameters (e.g., location and size of sub-bands) can be cell specific (e.g., configured in SIB 1) so that the parameters can be exchanged across neighbouring cells and proper coordination can be done to minimize the negative impacts (E.g., interference). Further, it reduces complexity of the nodes. The parameters like SBFD active time resource can be configured semi-statically or dynamically to improve the flexibility. The SBFD aware UE can update various parameters configured based on the SBFD configuration. E.g., the size of frequency range configured for DL operation (i.e., DL bandwidth part) can be updated in SBFD active time resource, if it overlaps with UL-SB configured.

[0045] Fig. 5 illustrates an exemplary overlap of a BWP of a UE with a sub-band for SBFD operation, in accordance with an embodiment of the present invention. In the example illustrated, the UE is configured with a DL BWP from resource blocks RB3 to RB5 and a UL sub-band for SBFD operation is defined from resource blocks RB 1 to RB4. Hence, in such an instance, there arises a partial overlap between the DL BWP of UE and UL sub-band for SBFD operation with respect to resource blocks RB3 and RB4, which are common for both the DL operation and UL operation. In SBFD active time resources from i.e., symbol 1 to 5, the BS performs UL operation using UL sub-band. Hence, the UE will not receive any DL signal in DL BWP overlapping with UL sub-band (i.e., in RB3 and RB4). Therefore, the SBFD aware UE can update the DL-BWP as RB5 in symbol 1 to 5, where SBFD is active, whereas the DL BWP of the UE consist of resource blocks RB3 to RB5 in other time resources such as symbol 0, symbol, 6 and symbol 7. However, the legacy UE is unaware of the SBFD operation or the parameters. Hence, the above adaptation of the configured BWP is not feasible for legacy UE.

[0046] To overcome these drawbacks, this invention focusses on the impact of SBFD on initial access and RACH procedure in cellular network and describe various methods to overcome the impacts. Also, the invention proposes various signalling exchange mechanisms and behaviour of nodes, to be defined, for efficient implementation of initial access and random-access procedure in a network enabled with SBFD.

[0047] The main objective of enabling SBFD in a network is to increase the number of DL / UL opportunities in the system. An UL-SB can be configured in a carrier, SBFD can be activated in a time resource configured for DL and UL operation can be performed within the resources in UL-SB.

[0048] Fig. 6a illustrates an exemplary TDD pattern configured using legacy method in NR for a set of 10 slots, in accordance with an embodiment of the present invention. Here, the carrier is configured for DL operation in first 6 slots, Flexible operation in 1 slot and UL operation in 3slots. Therefore, for the scenario disclosed in Fig. 6a, the BS can perform UL operation in last 3 slots alone which are slots 8 to 10.

[0049] Fig. 6b illustrates an exemplary TDD configuration after SBFD configuration, in accordance with an embodiment of the present invention. In the current scenario, an UL-SB is configured within the carrier and is activated in slots 2-7, so that UL operation can be enabled in slots 2-7, in addition to the legacy UL slots. However, the current NR specification has certain restrictions in performing DL and UL operations in a time resource configured as UL and DL, respectively. E.g., the UE treats the RO as invalid and does not transmit PRACH in the RO if it overlaps, even partially, with a set of symbols of a slot that are indicated as DL by the TDD configuration. However, in the case of SBFD, UL-SB can be defined within DL symbol and PRACH can be transmitted in the DL symbol. Therefore, to utilize the additional DL / UL opportunities created by SBFD, new mechanism to configure / schedule UL operations and new BS / UE behaviours is necessary and the foregoing sections thus discuss the various methods for configuring ROs in presence of SBFD and the behaviour of BS / UE for various scenarios arising due to SBFD.

[0050] In an embodiment of the present invention, the ROs can be configured by reusing the existing RACH configurations. The current RACH configuration configures RO in time resources configured as DL / UL / F by TDD configuration. The UE determines the validity of RO based on TDD configuration of the time resource and certain conditions. For example, the UE treats the RO in UL symbols as valid and transmits PRACH, whereas RO in DL symbols as considered invalid. Further, the RO in F symbols is considered as valid if the symbol is not configured for reception of control signal. The SBFD can generate additional ROs for transmission of PRACH. E.g., the RO in DL symbols can be valid if the DL symbol is configured for SBFD operation.

[0051] In another embodiment of the present invention, the ROs can be configured by introducing a new RACH configuration, referred as RACH configuration for SBFD in the invention. The additional ROs, configured by RACH configuration for SBFD, may fall on SBFD active time or non-SBFD time resource or both. Similarly, the RO can be within UL-SB, across UL-SB and DL- SB, etc. In another case, the BS ensures that the ROs created by RACH configuration for SBFD falls in resources where SBFD is active. In that case, the BS need to update the new RACH configuration according to the changes in SBFD configuration. The method for determining validity of the RO under these conditions have been disclosed in the foregoing sections.

[0052] In another embodiment of the present invention, for configuring new ROs using RACH configuration for SBFD, the RACH configuration for SBFD can give separate set of parameters that define new ROs. For example, separate PRACHconfigurationlndex that define new set of time locations for ROs, separate msgl -FDM to configure separate number of ROs multiplexed in a time instant, separate msgl-FrequencyStart to indicate different starting location for ROs in frequency domain. This also helps in configuring ROs within UL-SB or to avoid overlap of ROs with band configured for DL.

[0053] In another embodiment of the present invention, for configuring new ROs using RACH configuration for SBFD, the RACH configuration for SBFD can give some additional parameters which act upon the legacy RACH configuration to generate additional ROs.

[0054] In an embodiment, the additional parameter is an offset, which applies to the ROs configured by PRACHconfigurationlndex to get the additional ROs. The offset can be at frame level, subframe level, slot level or symbol level. For example, the PRACHconfigurationlndex indicate subframe numbers as (2,5) and offset indicate subframeoffset=^ then the SBFD aware UE determine ROs in subframes 2, 5, 6 and 9. In another example, the PRACHconfigurationlndex indicate subframe numbers as (2,5) and offset indicate subframeoffset=2 then the SBFD aware UE determine ROs in subframes 0, 2, 3, and 5. The offset can be for value of PRACH configuration index provided in RACH-ConfigCommon. E.g., legacy value of PRACH configuration index=98 and offset=10, then the SBFD aware UE use ROs provided by PRACH configuration index 98 and 108. In another e.g., legacy value of PRACH configuration index=70 and offset=5, then the SBFD aware UE use ROs provided by PRACH configuration index 65 and 70.

[0055] In another embodiment, the RACH configuration for SBFD can indicate a scaling factor that applies to the parameter configured by the PRACHconfigurationlndex to generate additional ROs. For example, scaling applies to the value of x configured by legacy PRACHconfigurationlndex. legacy indicate x=2 and y=0 indicating ROs in every even frame (nSFN Mod 2=0). Now, the RACH configuration for SBFD indicate xScaimg=0.5 which applies to x so that x ’=l and y=0. Therefore, based on the updated value of x, the ROs repeat in every frame (nSFN Mod 1=0). In another example, the scaling applies to number of PRACH slots with in subframe or number of PRACH occasions within a PRACH slot.

[0056] In yet another alternative, the RACH configuration for SBFD can indicate additional subframe numbers where ROs occur. For example, the legacy configuration indicate value of PRACH configuration index as 98 so that ROs occur in subframes 4 and 9. The additional configuration provides subframes_sbfd= {3,6,8} so that the SBFD aware UE assumes ROs configured by the value of PRACH configuration index in subframes {3, 4, 6, 8, 9}.

[0057] Fig. 7 illustrates possible scenarios for ROs in the presence of SBFD configuration, in accordance with an embodiment of the present invention. The details of such additional ROs and scenarios arising in a network by enabling SBFD and RO validation rules in the presence of SBFD have been described in the foregoing sections.

[0058] In an embodiment of the present invention, in the scenario of an additional RO being in a non-SBFD time resource, legacy rules as defined in NR are used for determining the validity of the RO. For example, the RO is not valid if it overlaps with DL time resource, RO is valid in F time resource if F time resource is not configured for reception of DL control information, and RO is valid in UL time resource. E.g., in Fig. 4, the RO1 and RO7 are configured in non-SBFD time resources, of which RO1 is invalid as it is in a DL symbol, whereas RO7 on an UL symbol is valid.

[0059] In another embodiment of the present invention, in the scenario of an additional RO being in a SBFD active time resource configured as DL by TDD configuration, it is invalid for legacy UE. However, the SBFD aware UE can use the RO. For determining the validity of RO in a DL SBFD active time resource and transmitting the PRACH, validity rules may be applied by the SBFD aware UE. In the first scenario, the RO configured within the UL sub band is valid. In view of such validity condition, RO2 as illustrated in Fig. 7 is invalid as it spans across DL-SB and UL-SB, whereas RO3, which is inside UL-SB, is valid. In the second scenario, the RO overlaps with the DL but PRACH transmission is allowed only in UL-SB. In view of such validity condition, both RO2 and RO3 as illustrated in Fig. 7 are valid. However, only the frequency resources in RO2, which overlaps with UL-SB, are used for transmission of PRACH. In the third scenario, the RO overlaps with the DL-SB and transmission is allowed in resources configured for SBFD operation. In view of such validity condition, both RO2 and RO3 as illustrated in Fig. 7 are valid. Here, the BS may avoid DL transmissions in the resources configured for RACH in DL-SB and can indicate a rate matching pattern to the UE configured with DL.

[0060] This creates additional ROs for the SBFD aware UEs and impacts the SSB-RO mapping. If the RO is valid and UE is performing transmission of PRACH, then in one method, the time resource can be converted to non-SBFD. i.e., the BS won’t be transmitting in DL so that the measurements on PRACH, at the BS, won’t be impacted by the DL transmission.

[0061] In another embodiment of the present invention, in the scenario of an additional RO being in a SBFD active time resource configured as Flexible by TDD configuration, the RO is valid for legacy UE. For determining the validity of RO in a flexible SBFD active time resource and transmitting the PRACH, validity rules may be applied by the SBFD aware UE. In the first scenario, the RO configured within the UL sub band is valid. In view of such validity condition, RO4 as illustrated in Fig. 7 is invalid as it spans across DL-SB and UL-SB, whereas RO5, which is inside UL-SB, is valid. The BS can ensure that the RO is configured within the UL-SB, so that the RO is valid for both legacy UE and SBFD aware UE. In an alternate embodiment, the configuration is not limiting the RO within the UL-SB. In that case, the RO will be valid for legacy UE, but not for SBFD aware UE. Therefore, number of ROs decrease for SBFD aware UE and can impact the SSB-RO mapping.

[0062] In the second scenario, the RO is valid even if it overlaps with DL-SB, but PRACH transmission can happen only within the UL-SB. In view of such validity condition, both RO4 and RO5 as illustrated in Fig. 7 are valid, however, only the frequency resources in RO4, which overlaps with UL-SB, are used for transmission of PRACH. In the third scenario, the RO is valid even if it overlaps with DL-SB, but transmission is allowed in resources configured for SBFD operation. In view of such validity condition, both RO4 and RO5 as illustrated in Fig. 7 are valid. Here, the BS may avoid DL transmissions in the resources configured for RACH in DL-SB and can indicate a rate matching pattern to the UE configured with DL.

[0063] In another embodiment of the present invention, in the scenario of an additional RO being in a SBFD active time resource configured as UL by TDD configuration, the RO is valid for legacy UEs. For determining the validity of RO in a UL SBFD active time resource and transmitting the PRACH, validity rules may be applied by the SBFD aware UE. In the first scenario, the RO configured within the UL sub band is valid. In the second scenario, the RO is valid even if it overlaps with DL-SB, but PRACH transmission can happen only within the UL- SB. In the third scenario, the RO is valid even if it overlaps with DL-SB, but transmission is allowed in resources configured for SBFD operation.

[0064] In another embodiment of the present invention, in the scenario of an additional RO being across a SBFD active time resource and a non-SBFD time resource, the legacy UE determines the validity of the RO based on the DL / UL / F configuration of the time resources. The SBFD aware UE either treats the RO as valid or determines the validity of the RO based on explicit indication from the BS. For transmitting PRACH, the SBFD aware UE assumes the same set of resources, same transmit power, etc. in the SBFD and non-SBFD time resources. The set of resources can either be the frequency resources of RO overlapping with UL-SB or can be configured by the RACH configuration. In the scenario where the validity of the RO is determined based on explicit indication from the BS, the BS can indicate, in RACH configuration for SBFD, whether the RO spanning across SBFD and non-SBFD time resources are valid or not. The indication can be common for the entire ROs configured by the RACH configuration for SBFD or it can be for a subset of the ROs configured.

[0065] It is established through the previous sections that the relative location of RO with respect to the sub-bands is an important factor in deciding the validity of an RO. For example, an RO in an SBFD active time resource is valid if it is within the UL-SB configured. The BS can ensure that an RO is within the UL-SB by modifying the frequency domain RACH configuration (i.e., MSG1 -FDM and msgl - requencyStart).

[0066] In an embodiment of the present invention, the BS can configure minimum value for the number of ROs multiplexed in frequency that in turn restrict the ROs within UL-SB configured. In one applicable scenario, the BS can configure small value for MSG1-FDM to restrict ROs within the UL-SB. Both legacy UE and SBFD aware UE will use the value configured in MSG1- FDM in all ROs. In another scenario, the BS can configure separate frequency domain multiplexing factor for SBFD aware UE. For example, the BS can configure MSG1 -FDM =8 and MSG1-FDM-SBFD=2, where MSG1-FDM-SBFD ensure ROs within the UL-SB. In another example, the BS can indicate a scaling factor that applies to the MSG1 -FDM provided by RACH- Config-common. If MSG1 -FDM= and MSG1-FDM- scaling-sbfd=Q.5 then SBFD aware UE assumes 4 ROs multiplexed in the frequency domain.

[0067] In another embodiment of the present invention, BS can configure the start frequency of ROs to vary in case SBFD is enabled. In an applicable scenario, the BS can indicate an additional offset msgl -FrequencyStart-SBFD, which ensures all ROs multiplexed in frequency domain is within the UL-SB. The SBFD aware UE apply the offset with respect to start of UL-SB configuredor the start of UL-BWP or start of UL-BWP overlapping with the UL-SB. In another scenario, the BS can indicate a scaling factor or additional offset which applies to the offset indicated by msgl -FrequencyStart and ensure all ROs within the UL-SB. In yet another scenario, the UE apply the msgl -FrequencyStart based on the SBFD configuration. For example, the UE determines the starting PRB of RO by applying the offset, indicated by msgl -FrequencyStart, from the first resource block of UL-SB configured for SBFD operation. In another example, the UE determine starting frequency of the RO by applying the offset from starting RB of the active BWP overlapping with UL-SB.

[0068] In yet another embodiment of the present invention, the BS can configure the additional offset needed between ROs or set of ROs multiplexed in frequency. Currently in NR, the ROs multiplexed in frequency domain are continuous in frequency. But, in the case of configuring DL- SB between an UL carrier (UDU scenario), the UL-SB may not be continuous. Therefore, it is difficult to restrict ROs within the UL-SB. In that case the additional offset is needed between ROs multiplexed in frequency to be within UL-SB. In an alternate embodiment, the additional offset is determined by the UE based on SBFD configuration. For example, the UE shift the RO whose start overlapping with DL-SB such that the RO starts from first RB after the DL-SB.

[0069] In an embodiment of the present invention, the modified frequency domain RACH configuration is applicable only for SBFD active time resources. For example, in case of receiving MSG1-FDM =8 and MSG1-FDM-SBFD=2, the UE assume 2 ROs multiplexed in frequency domain in an SBFD active time resource and 8 ROs multiplexed in non-SBFD active time resource. In another embodiment, the modified frequency domain RACH configuration is applicable for the additional ROs created due to SBFD. In yet another embodiment, the SBFD aware UE discard the legacy value of frequency domain RACH configuration and apply the modified frequency domain RACH configuration in all ROs.

[0070] The SBFD creates more UL occasions and additional ROs for the SBFD aware UEs. For example, the SBFD aware UEs can treat the ROs configured in DL SBFD active time resource as valid. Similarly, the SBFD aware UEs can use legacy ROs and the additional ROs configured by RACH configuration for SBFD. Further, the RO validation rule causes reduction in number of ROs for SBFD aware UEs. For example, if an RO is configured in an SBFD active time resource configured as F, then the legacy UEs treat the RO as valid irrespective of the overlap of RO with DL-SB. However, the SBFD aware UEs may treat the RO as invalid if the RO overlaps with theDL-SB or the RO falls outside the UL-SB. Therefore, the SBFD can create a mismatch in the number of ROs available for performing PRACH for legacy UEs and SBFD aware UEs, which creates discrepancies in the SSB-RO mapping between legacy UEs and SBFD aware UEs.

[0071] Fig. 8 illustrates SSB-RO mapping and RACH timings in the presence of SBFD, in accordance with an embodiment of the present invention. In Fig. 8 RO1, RO3 and RO6 are the legacy ROs indicated in orange colour and RO2, RO4 and RO5 are additional ROs indicated in green colour created due to SBFD. If an SSB burst has 3 SSBs and SSB / RO=1, then the SSB-RO mapping for legacy UE illustrated in yellow colour and SBFD aware UE illustrated in violet colour. The SSB-RO mapping is different for legacy and SBFD aware UE. In RO3, the legacy UE transmit PRACH preamble to indicate SSB2 is selected whereas SBFD aware UE transmit PRACH preamble in RO3 to indicate SSB3. If a BS receives a PRACH in RO3, then it can be mapped to SSB2 or SSB3 depending on the mapping, which in turn dependent on the type of UE. Further, the difference in the mapping leads to variations in association period and association pattern period for SBFD aware and legacy UEs. In the forthcoming sections, the SSB-RO mapping and associated timings (e.g., association period and pattern period) have been discussed for the scenarios involving SBFD. Also, the behaviour of BS and SBFD aware UE has been specified.

[0072] In an embodiment of the present invention, both legacy UEs and SBFD aware UEs follow the legacy procedure for SSB-RO mapping for the legacy ROs and compute association period, accordingly. The SBFD aware UEs compute the number of additional ROs, due to SBFD, within the association period and map them to the SSBs. The different methods for mapping additional ROs to the SSB have been discussed in the specification. The association period and association pattern period remain same as legacy and will not vary in accordance with this embodiment. In a first scenario, the additional ROs within an association period is divided equally among the SSBs. In a second scenario, the division is based on the legacy SSB / RO and CBPreamble / SSB / RO configured by RACHconfigcommon. In a third scenario, the division is based on the additional parameters given by RACH configuration for SBFD. For example, RACH configuration for SBFD provides SSB / RO-SBFD and CBPreamble / SSB / RO-SBFD so that the SBFD aware UEs divide the additional ROs accordingly. In another example, the RACH configuration for SBFD provides the ratio in which the additional ROs should be divided among the SSBs. In another example, the RACH configuration for SBFD can provide priority for SSB indicating which SSBs has to be mapped to additional ROs and which are not.

[0073] In another embodiment of the present invention, the SBFD aware UEs perform SSB-RO mapping independently for legacy ROs and additional ROs. In the first scenario, both mappings are performed based on the parameters configured by the legacy RACHconfigcommon. In a second scenario, a separate SSB / RO-SBFD and CBPreamble / SSB / RO-SBFD can be configured for the additional ROs by the RACH configuration for SBFD. The additional parameter can ensure that no change is made in association period. The association period is computed independently for legacy ROs (i.e., legacy association period) and additional ROs (i.e., association period for SBFD) and the effective association period is determined as the maximum of legacy association period and association period for SBFD. Further, the association pattern period is determined based on the effective association period.

[0074] In another embodiment of the present invention, the UEs perform SSB-RO mapping in a legacy manner, i.e., the legacy UE maps the SSBs to legacy ROs and SBFD aware UE maps SSBs to both legacy and additional ROs in a legacy manner. Since the number of ROs differ for legacy and SBFD aware UE, the mapping and timing related to RACH are different for legacy UE and SBFD aware UE. To overcome the discrepancy, between legacy and SBFD aware UE, the BS configures separate set of preambles for SBFD aware UE for performing RACH.

[0075] In another embodiment of the present invention, various methods can be considered for configuring separate set of preambles. An explicit set of preambles for SBFD aware UE for performing RACH can be configured in RACH configuration for SBFD. In a first scenario, a subset of other purpose preambles as additional set of preambles for SBFD aware UEs for performing RACH is configured. The totalNumberOfRA-Preambles in RACH-ConfigCommon gives the total number of CB and CF PRACH preambles in a RO. Difference between 64 and totalNumberOfRA-Preambles gives the preamble for other purpose in a RO. E.g., totalNumberOfRA-Preambles-SBFD indicate the number of preambles, from the set of preambles for other purpose, available for SBFD aware UE for performing RACH.

[0076] In a second scenario, a subset of CF preambles as additional set of preambles for SBFD aware UEs for performing RACH is configured. The -perRACH-OccasionAndCB- PreamblesPerSSB determines the number of CB preambles. Difference between totalNumberOfRA-Preambles and Preambles calculated from ssb-perRACH-OccasionAndCB- PreamblesPerSSB gives the CF preambles in a RO. For example, totalNumberOfRA-Preambles-SBFD indicate the number of preambles, from the set of CF preambles, available for SBFD aware UE for performing RACH.

[0077] In a third scenario, a separate set of root sequence and cyclic shift in RACH- ConfigCommon so that SBFD aware UE generate additional set of preambles in a RO is configured.

[0078] In a fourth scenario, a Restrictedset in RACH-ConfigCommon is configured so that the legacy UEs use higher cyclic shift for generating preamble from root sequence or skip some of the preambles generated. Define a new parameter unRestrictedset-SBFD for SBFD aware UE and indicate Unrestricted to use smaller cyclic shift for generating preamble or to use the preambles skipped, due to legacy Restrictedset configuration, to generate additional set of preambles.

[0079] In another embodiment of the present invention, an implicit rule is defined in determining additional set of RACH preambles for SBFD aware UE. For example, the first 10 preambles configured for CF PRACH is treated as additional set of preambles by the SBFD aware UE. In another example, the first 10 preambles configured for other purposes are treated as additional set of preambles by the SBFD aware UE.

[0080] In an embodiment of the present invention, the SBFD aware UE can perform alternative methods for SSB-RO mapping with the additional set of preambles. In the first alternative, the SBFD aware UE uses preambles from the additional set for performing RACH in all ROs. The BS, after receiving the preamble, check whether the preamble is legacy preamble or preamble from the additional set configured. In the former case, BS determines the preamble is received from a legacy UE whereas in latter the preamble is from SBFD aware UE. In case of determining the preamble is received from a legacy UE, the BS uses only legacy ROs in determining the SSB- RO mapping pattern and the SSB corresponding to the preamble received. On the other hand, if the preamble received belongs to the additional set configured, then the BS use both legacy ROs and additional ROs, created due to SBFD, in determining the SSB-RO mapping pattern and the SSB corresponding to the preamble received.

[0081] In the second alternative, the SBFD aware UE uses preambles from additional set for performing RACH in common ROs and uses both legacy preambles and preambles from the additional set for performing RACH in additional ROs. In a common RO, the BS receives the RACH preamble and determines whether the preamble is transmitted by legacy UE or SBFDaware UE depending on the preamble received. In case of determining that the preamble is received from a legacy UE, the BS uses only legacy ROs in determining the SSB-RO mapping pattern and the SSB corresponding to the preamble received. On the other hand, if the preamble received belongs to the additional set configured, then the BS uses both legacy ROs and additional ROs, created due to SBFD, in determining the SSB-RO mapping pattern and the SSB corresponding to the preamble received. In an additional RO, created by SBFD, only SBFD aware UE transmits preamble. Therefore, separate set of preambles is not needed for SBFD aware UE. Hence, in additional RO, the SBFD aware UEs use a preamble selected from a set containing both legacy preambles and preambles in additional set.

[0082] The advantage here is that the number of preambles increases, which reduces the probability of contention or conflict. The BS is also aware that the preamble received in an additional RO is from SBFD aware UE and uses both legacy ROs and additional ROs in determining the SSB-RO mapping pattern and the SSB corresponding to the preamble received. For example, if P_legacy={pl, p2, p3, p4 } and P_SBFD={plO, pl6, p20} are the set of legacy and additional preambles, respectively, configured by the BS to the UE for performing RACH, in case of receiving p2 in RO3 in Fig. 6a and Fig. 6b, the BS identifies the preamble transmitted by the legacy UE and determines the SSB2 as the SSB corresponding to the preamble p2, using legacy SSB-RO mapping. In case of receiving pl6 in RO3 in Fig. 8, the BS identifies the UE as SBFD aware UE and maps the preamble to SSB3, using the SSB-RO mapping for SBFD. In case of receiving a preamble, either from the set P_legacy or P_SBFD, in RO2 (i.e., additional RO) in Fig. 8, BS identifies the preamble transmitted by an SBFD aware UE and determines the SSB2 as the SSB corresponding to the preamble received.

[0083] In an embodiment of the present invention, a proposed method may be performed by a UE for performing transmission and / or reception of signals. Fig. 9 illustrates a flowchart of steps of the proposed method executed by a first node, in accordance with an embodiment of the present invention. The first node is one of a legacy UE and a SBFD aware UE. Step S901 involves receiving at least one TDD configuration, at least one random access (RACH) configuration, and at least one SBFD configuration by a UE, either contiguously or in intervals. Herein, the TDD configuration is responsible for configuring time resource as either uplink (UE) time resource, downlink (DE) time resource or Flexible (F) time resource. The SBFD configuration is responsible for configuring at least one uplink sub-band, at least one downlink sub-band and at least one SBFD time resource. The SBFD time resource is a subset of the time resource configuredthrough the TDD configuration and is contiguous. Further, the RACH configuration is responsible for configuring plurality of RACH occasions (ROs).

[0084] In Step S901, receiving a RACH configuration includes the steps of receiving at least one frequency offset and interpreting, for at least one RO in the at least one SBFD time resource and for at least one second RO, the at least one frequency offset as the frequency offset of lowest RO in frequency domain with respective to one of the lowest frequency resource in the UL sub-band, the lowest frequency resource in the UL bandwidth part and the lowest frequency resource from the frequency resources overlapping with the UL sub-band and UL bandwidth part. The valid RO is one of a first RO and a second RO, wherein the at least one first RO is in the at least one time resource configured as one of the UL time resource and the F time resource by the at least one TDD configuration and wherein the at least one second RO is at least one of within frequency resource that are both in the active UL bandwidth part and in the UL sub-band, within the at least one time resource configured as DL time resource by the at least one TDD configuration; and one of within the at least one SBFD time resource; and across the at least one SBFD time resource and at least one non-SBFD time resource.

[0085] The RO that starts from the at least one SBFD time resource and ends in a non-SBFD time resource is valid when the RO is within the frequency resources that are both in the at least one UL sub-band and active UL bandwidth part, the RO is configured by the at least one second RACH configuration for the at least one SBFD time resource and the at least one first node receives an explicit indication. The proposed method indicates that the RO is valid if it meets any of the conditions, the first condition is that the RO is within the UL time resource, another condition is that the RO is within the frequency resources that are both in the at least one UL subband and active UL bandwidth part of the at least one SBFD time resource and a further condition is that the RO is in the frequency resources that are both in the at least one UL sub-band and active UL bandwidth part starting from the at least one SBFD time resource and ends in a non- SBFD time resource. This is valid only when the RO is configured by at least one second RACH configuration and the at least one first node receives an explicit indication. The at least one SBFD time resource includes the at least one-time resource indicated as DL time resource by the at least one TDD configuration.

[0086] The RACH configuration as received in S901 comprises receiving a first RACH configuration and a second RACH configuration. The first RACH configuration includesparameters such as scheduling information of at least one first RO, an at least one first time resource, an at least one first frequency resource, an at least one first frequency offset, number of preambles per RO, number of SSBs sharing a RO, number of contention-based preambles per SSB per RO, number of ROs multiplexed in frequency domain and an at least one index from a predefined table.

[0087] The second RACH configuration includes parameters such as scheduling information of at least one second RO, an at least one second time resource, an at least one second frequency resource, an at least one second frequency offset, a number of ROs multiplexed in frequency domain, at least one index from a predefined table, at least one offset, at least one scaling factor, total number of preambles per RO for the at least one SBFD time resource, number of SSBs sharing a RO for the at least one SBFD time resource, priority of SSB indices for SSB -RO mapping in the at least one SBFD time resource, at least one SSB index for SSB-RO mapping in the at least one SBFD time resource, number of contention-based preambles per SSB per RO for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource and at least one number. The offset is at least one of frame offset, subframe offset, slot offset, symbol offset and a frequency offset. The number is at least one of subframe number, slot number, and symbol number. Further, at least one second RACH configuration configures random access parameters for the at least one SBFD time resource. Herein, the at least one RACH preamble for the at least one SBFD time resource comprises at least one root sequence, at least one cyclic shift, reusing non-RACH preamble; and at least one preamble from contention free preamble.

[0088] The explicit indication indicates whether the configured ROs across the at least one non- SBFD time resource and the at least one SBFD time resource is valid and is in the at least one second RACH configuration which configures random access parameters for the at least one SBFD time resource. The RO starting from the at least one SBFD time resource and ends in a non-SBFD time resource comprises at least one parameter for transmitting the RACH preamble is same in the portion of the RO overlapping with the at least one SBFD time resource and the at least one non-SBFD time resource, wherein the parameter is one of at least one frequency resource for transmission, and transmit power.

[0089] S901 further includes transmitting a first RACH preamble in a first RO and a second RACH preamble in a second RO, wherein the second RACH preamble is for the at least one SBFD time resource and is one of predefined and received by the at least one first node.

[0090] Step S902 involves receiving active SSB indices within an SSB burst. Step S903 involves mapping at least one valid RO from the plurality of ROs to the active SSB indices. Herein, determination of validity of an RO is based on at least one TDD configuration, at least one SBFD configuration and a pre-defined set of validity conditions. The at least one SBFD time resource overlapping with the at least one valid RO is treated as one of the UL time resource and a non- SBFD time resource. Herein, mapping at least one valid RO comprises mapping the at least one first RO to the active SSB indices and computing a first RACH association period for the at least one first RO. The mapping at least one valid RO comprises mapping the at least one second RO to the active SSB indices and computing a second RACH association period for the at least one second RO. Computing the first RACH association period further comprises mapping the at least one second RO within the first RACH association period to the active SSB indices, wherein the mapping is one of dividing the at least one second RO within the first RACH association period equally among the active SSB indices, based on at least one parameter configured by at least one first RACH configuration; and based on at least one parameter configured by at least one second RACH configuration.

[0091] The mapping further comprises for the first RO, computing a first RACH association pattern period based on the first RACH association period and computing effective RACH association period as maximum of the first RACH association period and the second RACH association period. The mapping further comprises for the second RO, computing a second RACH association pattern period based on the second RACH association period and computing effective RACH association pattern period based on the effective RACH association period.

[0092] In an embodiment of the present invention, the method as proposed includes receiving plurality of SSB beams and determining reference signal received power (RSRP) value corresponding to the plurality of SSB beams. Then the determined RSRP value is compared with a configured threshold wherein once the value of an SSB beam crosses the threshold, it is selected as the best beam. Once a valid RO is mapped into the best beam, a RACH preamble is then transmitted through the valid RO. The mapping is based on at least one parameter configured by at least one first RACH configuration wherein mapping for the at least one first RO is based onat least one parameter configured by at least one first RACH configuration and mapping for the at least one second RO is based on at least one parameter configured by at least one second RACH configuration.

[0093] In an embodiment of the present invention, another proposed method may be performed by a BS for performing transmission and / or reception of signals. Fig. 10 illustrates a flowchart of steps of the proposed method executed by a second node, in accordance with an embodiment of the present invention. Step S1001 involves transmitting a plurality of SSB beams, at least one TDD configuration, at least one random access (RACH) configuration, and at least one SBFD configuration, wherein the transmission is performed as one of contiguously and in intervals. Herein, the TDD configuration is responsible for configuring time resource as either uplink (UL) time resource, downlink (DL) time resource or Flexible (F) time resource. The SBFD configuration is responsible for configuring at least one uplink sub-band, at least one downlink sub-band and at least one SBFD time resource. The SBFD time resource is a subset of the time resource configured through the TDD configuration and is contiguous. Further, the RACH configuration is responsible for configuring plurality of RACH occasions (ROs), which comprises at least one first RO and at least one second RO. Here, the at least one first RO is in the at least one time resource configured as one of the UL time resource and the F time resource by the at least one TDD configuration. Further, the at least one second RO is at least one of within frequency resource that are both in the active UL bandwidth part and in the UL sub-band, within the at least one time resource configured as DL time resource by the at least one TDD configuration; and one of within the at least one SBFD time resource; and across the at least one SBFD time resource and at least one non-SBFD time resource. The second node in accordance with the embodiment is a base station.

[0094] Step S1001 further involves performing the steps of transmitting active SSB indices within an SSB burst, configuring minimum reference signal received power (RSRP) value that an SSB beam should have, transmitting at least one frequency offset, transmitting an indication to perform a random access procedure using one of at least one first RO and at least one second RO, transmitting at least one first RACH configuration, transmitting at least one second RACH configuration, transmitting first set of RACH preamble, transmitting a second set of RACH preamble for the at least one SBFD time resource and transmitting an explicit indication indicating whether an RO from the plurality of ROs starting from the at least one SBFD time resource and ending in a non-SBFD time resource is valid when the RO is within the frequency resources thatare both in the at least one UL sub-band and active UL bandwidth part, the RO is configured by the at least one second RACH configuration for the at least one SBFD time resource and the at least one first node receives an explicit indication. Herein, the RO is configured by the at least one second RACH configuration and wherein the at least one second RACH configuration configures at least one parameter for the at least one SBFD time resource. The at least one SBFD time resource is a subset of the at least one time resource configured by the TDD configuration.

[0095] The determination of validity of a RO is based on the determination of whether the RO is within the UL time resource, the RO is within the frequency resources that are both in the at least one UL sub-band and active UL bandwidth part of the at least one SBFD time resource and the RO is in the frequency resources that are both in the at least one UL sub -band and active UL bandwidth part starting from the at least one SBFD time resource and ends in a non-SBFD time resource. Here, the at least one SBFD time resource includes the at least one time resource indicated as DL time resource by the at least one TDD configuration. Further, the RO starting from the at least one SBFD time resource and ends in a non-SBFD time resource comprises at least one parameter for receiving the RACH preamble is same in the portion of the RO overlapping with the at least one SBFD time resource and the at least one non-SBFD time resource and is deemed valid only if the RO is configured by at least one second RACH configuration for the at least one SBFD time resource and the at least one second node provides an explicit indication. The parameter here comprises at least one frequency resource for reception, and transmit power.

[0096] In an embodiment, the transmission of at least one first RACH includes transmission of at least one of scheduling information of at least one first RO, an at least one first time resource, an at least one first frequency resource, an at least one first frequency offset, total number of preambles per RO, number of SSBs sharing a RO, number of contention based preambles per SSB per RO, number of ROs multiplexed in frequency domain and an at least one index from a predefined table. Herein, the at least one frequency offset is the frequency offset of lowest RO in frequency domain with respective to one of the lowest frequency resource in the UL sub-band, the lowest frequency resource in the UL bandwidth part and the lowest frequency resource from the frequency resources overlapping with the UL sub-band and UL bandwidth part and such frequency offset is applicable for at least one RO in the at least one SBFD time resource and at least one second RO.

[0097] In an embodiment, the transmission of at least one second RACH includes transmission of at least one of scheduling information of at least one second RO, an at least one second time resource, an at least one second frequency resource, an at least one second frequency offset, a number of ROs multiplexed in frequency domain, at least one index from a predefined table, at least one offset, at least one scaling factor, total number of preambles per RO for the at least one SBFD time resource, number of SSBs sharing a RO for the at least one SBFD time resource, priority of SSB indices for SSB-RO mapping in the at least one SBFD time resource, at least one SSB index for SSB-RO mapping in the at least one SBFD time resource, number of contention based preambles per SSB per RO for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, and at least one number. Here, the at least one offset is at least one of frame offset, subframe offset, slot offset, symbol offset and a frequency offset and the at least one number is at least one of subframe number, slot number, and symbol number.

[0098] Step S1002 involves receiving from at least one first node a RACH preamble in a valid RO from a plurality of valid ROs, wherein the determination of validity of plurality of ROs is based on the at least one TDD configuration, the at least one SBFD configuration, and a predefined set of validity conditions.

[0099] Step S1003 involves identifying best SSB beam for the at least one first node from the plurality of SSB beams based on the RACH preamble and the valid RO. Herein, the step of identifying the best SSB beam further comprises mapping the plurality of valid ROs to the active SSB indices, identifying at least one SSB beam corresponding to the valid RO and identifying the best SSB beam from the at least one SSB beam based on the RACH preamble and the at least one RACH configuration.

[0100] In an embodiment of the present invention, the mapping comprises mapping the at least one first RO to the active SSB indices and mapping the at least one second RO to the active SSB indices and mapping is based on at least one parameter configured by at least one first RACH configuration. Thus, mapping the at least one first RO is based on at least one parameter configured by at least one first RACH configuration and mapping the at least one second RO is based on at least one parameter configured by at least one second RACH configuration. The step of mapping at least one first RO also includes computing a first RACH association period for the at least one first RO, computing a first RACH association pattern period based on the first RACHassociation period and computing effective RACH association period as maximum of the first RACH association period and the second RACH association period. The step of mapping at least one second RO also includes computing a second RACH association period for the at least one second RO, computing a second RACH association pattern period based on the second RACH association period and computing effective RACH association pattern period based on the effective RACH association period.

[0101] In an embodiment of the present invention, computing the first RACH association period further comprises mapping the at least one second RO within the first RACH association period to the active SSB indices wherein mapping is one of dividing the at least one second RO within the first RACH association period equally among the active SSB indices; based on at least one parameter configured by at least one first RACH configuration; and based on at least one parameter configured by at least one second RACH configuration.

[0102] In another embodiment, transmitting the second set of RACH preamble for the at least one SBFD time resource comprises transmitting at least one of at least one root sequence, at least one cyclic shift, index of at least one non-RACH preamble; and index of at least one preamble from contention free preamble. Further, identifying the best SSB beam comprises identifying at least one of type of SSB-RO mapping and type of the at least one first node. Herein, type of the SSB-RO mapping comprises one of SSB-RO mapping considering only at least one first RO; SSB-RO mapping considering only at least one second RO; and SSB-RO mapping considering both at least one first RO and at least one second RO. Further, identifying comprises at least one of identifying the at least one first node as SBFD aware UE; identifying the SSB-RO mapping include one of at least one second RO only; and both at least one first RO and at least one second RO, when at least one of the RACH preamble is from a second set of RACH preamble and the valid RO is from the at least one second RO. The second set of RACH preamble is configured for the at least one SBFD time resource and the at least one second RO is configured for the at least one SBFD time resource. Further, the at least one SBFD time resource overlapping with at least one valid RO from the plurality of valid RO is treated as one of the UL time resource and a non- SBFD time resource.

[0103] FIG. 11 illustrates a general block diagram of the node 1100, according to an embodiment of the present disclosure. As an example, the node 1100 may be any user equipment like smart phone, mobile, communicating with another node like a base station.

[0104] In an example, the processor(s) 1101 may be a single processing unit or a number of units, all of which could include multiple computing units. The processor(s) 1101 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logical processors, virtual processors, state machines, logic circuitries, and / or any devices that manipulate signals based on operational instructions. Among other capabilities, the processor(s) 1101 is configured to fetch and execute computer-readable instructions and data stored in a memory 1103.

[0105] The memory 1103 may include any non-transitory computer-readable medium known in the art including, for example, volatile memory, such as static random-access memory (SRAM) and dynamic random-access memory (DRAM), and / or non-volatile memory, such as read-only memory (ROM), erasable programmable ROM, flash memories, hard disks, optical disks, and magnetic tapes.

[0106] The processors 1101 may include one or more general purpose processors (e.g., INTEL® or Advanced Micro Devices® (AMD) microprocessors) and / or one or more special purpose processors (e.g., digital signal processors or Xilinx® System on Chip (SOC) Field Programmable Gate Array (FPGA) processor), MIPS / ARM-class processor, a microprocessor, a digital signal processor, an application specific integrated circuit, a microcontroller, a state machine, or any type of programmable logic array.

[0107] The memory 1103 may include, but is no limited to, non-transitory machine -readable storage devices such as hard drives, magnetic tape, floppy diskettes, optical disks, Compact Disc Read-Only Memories (CD-ROMs), and magneto-optical disks, semiconductor memories, such as ROMs, Random Access Memories (RAMs), Programmable Read-Only Memories (PROMs), Erasable PROMs (EPROMs), Electrically Erasable PROMs (EEPROMs), flash memory, magnetic or optical cards, or other type of media / machine -readable medium suitable for storing electronic instructions.

[0108] In an example, the module(s), engine(s), and / or unit(s) 1107 may include a program, a subroutine, a portion of a program, a software component or a hardware component capable of performing a stated task or function. As used herein, the module(s), engine(s), and / or unit(s) may be implemented on a hardware component such as a server independently of other modules, or a module can exist with other modules on the same server, or within the same program. The module(s), engine(s), and / or unit(s) 1107 may be implemented on a hardware component such as processor one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and / or any devices that manipulate signals based on operational instructions. The module (s), engine(s), and / or unit(s) 1107 when executed by the processor(s) 1101 may be configured to perform any of the described functionalities.

[0109] As a further example, the database 1105 may be implemented with integrated hardware and software. The hardware may include a hardware disk controller with programmable search capabilities or a software system running on general-purpose hardware. Examples of databases are but are not limited to, in-memory databases, cloud databases, distributed databases, embedded databases, and the like. The database amongst other things, serves as a repository for storing data processed, received, and generated by one or more of the processors(s) 1101, and the modules / engines / units.

[0110] The modules / engines / units 1107 may be implemented with an Al module that may include a plurality of neural network layers. Examples of neural networks include, but are not limited to, a convolutional neural network (CNN), a deep neural network (DNN), a recurrent neural network (RNN), a Restricted Boltzmann Machine (RBM). The learning technique is a method for training a predetermined target device using a plurality of learning data to cause, allow, or control the target device to decide or prediction. Examples of the learning techniques include, but are not limited to, a supervised learning, unsupervised learning, a semi- supervised learning, or reinforcement learning. At least one of a plurality of CNN, DNN, RNN, RMB models and the like may be implemented to thereby achieve execution of the present subject matter’s mechanism through an Al model. A function associated with the Al model may be performed through the non-volatile memory, the volatile memory, and the processor. The processor may include one or a plurality of processors. At this time, one or a plurality of processors may be a general-purpose processor, such as a central processing unit (CPU), an application processor (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and / or an Al-dedicated processor such as a neural processing unit (NPU). The one or a plurality of processors control the processing of the input data in accordance with a predefined operating rule or the artificial intelligence (Al) model stored in the non-volatile memory and the volatile memory. The predefined operating rule or artificial intelligence model is provided through training or learning.

[0111] As an example, the display unit 1109 includes a computer monitor, a touch screen, an output device capable of displaying the graphics, and the like. The display unit 1109 is configured to display visual output in the UEs, desktops, laptops, and workstations. The display unit 1109 may come in different sizes, resolutions, and types (such as LCD, LED, or OLED).

[0112] As a further example, the network interface 1111 is configured to provide and establish communication with any electronic device via a public network, private network, or any wireless communication technology.

[0113] The figures of the disclosure are provided to illustrate some examples of the invention described. The figures are not to limit the scope of the depicted embodiments or the appended claims. Aspects of the disclosure are described herein with reference to the invention to example embodiments for illustration. It should be understood that specific details, relationships, and method are set forth to provide a full understanding of the example embodiments. One of ordinary skill in the art recognize the example embodiments can be practiced without one or more specific details and / or with other methods.

[0114] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any disclosures or of what may be claimed, but rather as descriptions of features specific to particular embodiments of particular disclosures. Certain features that are described herein in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub combination or variation of a sub combination.

[0115] Thus, particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous.

[0116] It is to be understood that the disclosure is not to be limited to the specific embodiments disclosed, and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation, unless described otherwise.

Claims

1. WE CLAIM:

1. A method for communicating in a network enabled with a sub-band full duplexing (SBFD), the method comprising: receiving, by at least one first node, at least one TDD configuration, at least one random access (RACH) configuration, and at least one SBFD configuration, wherein the at least one TDD configuration configures at least one time resource as at least one of a downlink (DL) time resource, an uplink (UL) time resource, and a flexible (F) time resource, wherein the at least one SBFD configuration configures at least one uplink sub-band, at least one downlink sub band and at least one SBFD time resource, and wherein the at least one RACH configuration configures a plurality of RACH occasions (ROs); receiving, by the at least one first node, active SSB indices within an SSB burst; and mapping, by the at least one first node, at least one valid RO from the plurality of ROs to the active SSB indices, wherein the at least one valid RO is based on the at least one TDD configuration, the at least one SBFD configuration, and a pre-defined set of validity conditions.

2. The method as claimed in claim 1, further comprises: receiving a plurality of SSB beams; determining a reference signal received power (RSRP) value corresponding to the plurality of SSB beams; comparing the RSRP values with a threshold configured; and selecting an SSB beam with the RSRP value crossing the threshold as a best beam.

3. The method as claimed in claim 2, further comprises: transmitting, by the at least one first node, a RACH preamble in a valid RO from the at least one valid RO,wherein the valid RO maps to the S SB beam.

4. The method as claimed in claim 1, wherein the at least one SBFD time resource overlapping with the at least one valid RO is treated as one of: a. the UL time resource, and b. a non-SBFD time resource.

5. The method as claimed in claim 1, wherein the at least one first node is one of: a. a legacy UE, and b. a SBFD aware UE.

6. The method as claimed in claim 1, wherein the at least one SBFD time resource is a subset of the at least one time resource.

7. The method as claimed in claim 1, wherein a RO from the plurality of RO that starts from the at least one SBFD time resource and ends in a non-SBFD time resource is the at least one valid RO when at least one of: a. the RO is within frequency resources that are both in the at least one UL sub-band and active UL bandwidth part, b. the RO is configured by at least one second RACH configuration for the at least one SBFD time resource, and c. the at least one first node receives an explicit indication.

8. The method as claimed in claim 1, wherein the at least one valid RO one of: a. is within the UL time resource, b. is within frequency resources that are both in the at least one UL sub-band and active UL bandwidth part of the at least one SBFD time resource, andc. is in the frequency resources that are both in the at least one UL sub-band and active UL bandwidth part starting from the at least one SBFD time resource and ends in a non-SBFD time resource.

9. The method as claimed in claim 8, wherein the at least one SBFD time resource include the at least one time resource indicated as DL time resource by the at least one TDD configuration.

10. The method as claimed in claim 8, wherein a RO starting from the at least one SBFD time resource and ends in a non-SBFD time resource is valid only when the RO is configured by at least one second RACH configuration; and the at least one first node receives an explicit indication.

11. The method as claimed in claim 10, wherein the explicit indication indicates whether the configured ROs across the at least one non-SBFD time resource and the at least one SBFD time resource is valid.

12. The method as claimed in claim 10, wherein the explicit indication is in the at least one second RACH configuration.

13. The method as claimed in claim 10, wherein the at least one second RACH configuration configures random access parameters for the at least one SBFD time resource.

14. The method as claimed in claim 8, wherein, a RO starting from the at least one SBFD time resource and ends in a non-SBFD time resource comprises: at least one parameter for transmitting a RACH preamble is same in the portion of the RO overlapping with the at least one SBFD time resource and the at least one non-SBFD time resource.

15. The method as claimed in claim 14, wherein the at least one parameter comprises at least one of: at least one frequency resource for transmission, and a transmit power.

16. The method as claimed in claim 1, wherein receiving, by at least one first node, at least one TDD configuration, at least one random access (RACH) configuration, and at least one SBFD configuration is one of: received contiguously; and received in intervals.

17. The method as claimed in claim 1, wherein receiving the at least one RACH configuration comprises at least one of: receiving, by the at least one first node, at least one first RACH configuration, and receiving, by the at least one first node, at least one second RACH configuration.

18. The method as claimed in claim 17, wherein the at least one first RACH configuration comprises at least one of: scheduling information of at least one first RO, an at least one first time resource, an at least one first frequency resource, an at least one first frequency offset, a total number of preambles per RO, a number of SSBs sharing a RO, a number of contention based preambles per SSB per RO, a number of ROs multiplexed in frequency domain, and an at least one index from a predefined table.

19. The method as claimed in claim 17, wherein the at least one second RACH configuration comprises at least one of: scheduling information of at least one second RO, an at least one second time resource,an at least one second frequency resource, an at least one second frequency offset, a number of ROs multiplexed in frequency domain, at least one index from a predefined table, at least one offset, at least one scaling factor, a total number of preambles per RO for the at least one SBFD time resource, a number of SSBs sharing a RO for the at least one SBFD time resource, a priority of SSB indices for SSB-RO mapping in the at least one SBFD time resource, at least one SSB index for SSB-RO mapping in the at least one SBFD time resource, a number of contentions based preambles per SSB per RO for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, and at least one number.

20. The method as claimed in claim 19, wherein the at least one offset is at least one of frame offset, subframe offset, slot offset, symbol offset and a frequency offset.

21. The method as claimed in claim 19, wherein the at least one number is at least one of subframe number, slot number, and symbol number.

22. The method as claimed in claim 17, wherein the at least one second RACH configuration configures random access parameters for the at least one SBFD time resource.

23. The method as claimed in at least one of claim 1, wherein receiving the at least one RACH configuration comprises: receiving at least one frequency offset; andinterpreting the at least one frequency offset as the frequency offset of lowest RO in frequency domain with respective to one of: a lowest frequency resource in the at least one UL sub band, a lowest frequency resource in the UL bandwidth part, and a lowest frequency resource from the frequency resources overlapping with the at least one UL sub band and a UL bandwidth part.

24. The method as claimed in claim 23, wherein interpreting is for at least one of: at least one RO in the at least one SBFD time resource, and at least one second RO.

25. The method as claimed in claim 1, wherein the at least one valid RO comprises at least one of: at least one first RO, and at least one second RO.

26. The method as claimed in claim 25, wherein the at least one first RO is in the at least one time resource configured as one of UL time resource and the F time resource by the at least one TDD configuration.

27. The method as claimed in claim 25, wherein the at least one second RO is at least one of: within frequency resource that are both in the active UL bandwidth part and in the at least one UL sub-band, within the at least one time resource configured as DL time resource by the at least one TDD configuration, and one of: within the at least one SBFD time resource; andacross the at least one SBFD time resource and at least one non-SBFD time resource.

28. The method as claimed in claim 25, comprises at least one of: a. mapping the at least one first RO to the active SSB indices, and b. mapping the at least one second RO to the active SSB indices.

29. The method as claimed in claim 28, wherein the mapping is based on at least one parameter configured by at least one first RACH configuration.

30. The method as claimed in claim 28, wherein a. mapping for the at least one first RO is based on at least one parameter configured by at least one first RACH configuration, and b. mapping for the at least one second RO is based on at least one parameter configured by at least one second RACH configuration.

31. The method as claimed in claim 28, further comprises at least one of: a. computing a first RACH association period for the at least one first RO; and b. computing a second RACH association period for the at least one second RO.

32. The method as claimed in claim 31, further comprises: a. computing a first RACH association pattern period based on the first RACH association period; and b. computing a second RACH association pattern period based on the second RACH association period.

33. The method as claimed in claim 31, further comprises: a. computing effective RACH association period as maximum of the first RACH association period and the second RACH association period; andb. computing effective RACH association pattern period based on the effective RACH association period.

34. The method as claimed in claim 31, wherein computing the first RACH association period further comprises: a. mapping the at least one second RO within the first RACH association period to the active SSB indices.

35. The method as claimed in claim 34, wherein mapping is one of: a. dividing the at least one second RO within the first RACH association period equally among the active SSB indices, b. based on at least one parameter configured by at least one first RACH configuration, and c. based on at least one parameter configured by at least one second RACH configuration.

36. The method as claimed in claim 25, comprises at least one of: a. transmitting a first RACH preamble in a first RO from the at least one first RO and b. transmitting a second RACH preamble in a second RO from the at least one second RO.

37. The method as claimed in claim 36, wherein the second RACH preamble is for the at least one SBFD time resource and is one of: a. predefined; and b. received by the at least one first node.

38. The method as claimed in claim 19, wherein the at least one RACH preamble for the at least one SBFD time resource comprises at least one of: a. at least one root sequence, b. at least one cyclic shift, c. reusing non-RACH preamble, andd. at least one preamble from contention free preamble.

39. The method as claimed in claim 1, wherein the at least one SBFD time resource is contiguous.

40. A method for communicating in a network enabled with sub-band full duplexing (SBFD), the method comprising: transmitting, by at least one second node, a plurality of SSB beams, at least one TDD configuration, at least one random access (RACH) configuration, and at least one SBFD configuration, wherein the at least one TDD configuration configures at least one time resource as at least one of a downlink (DL) time resource, an uplink (UL) time resource, and a flexible (F) time resource, wherein the at least one SBFD configuration configures at least one uplink sub-band, at least one downlink sub-band and at least one SBFD time resource, and wherein the at least one RACH configuration configures a plurality of RACH occasions (ROs); receiving, by the at least one second node, from at least one first node a RACH preamble in a valid RO from a plurality of valid ROs, wherein the plurality of valid RO is based on: the at least one TDD configuration, the at least one SBFD configuration, and a pre-defined set of validity conditions; and identifying, by the at least one second node, best SSB beam for the at least one first node from the plurality of SSB beams based on the RACH preamble and the valid RO.

41. The method as claimed in claim 40, wherein transmitting further comprises at least one of: transmitting active SSB indices within an SSB burst, configuring minimum reference signal received power (RSRP) value that an SSB beam should have, transmitting at least one frequency offset,transmitting an indication to perform a random-access procedure using one of at least one first RO and at least one second RO, transmitting at least one first RACH configuration, transmitting at least one second RACH configuration, transmitting first set of RACH preamble, transmitting a second set of RACH preamble for the at least one SBFD time resource, and transmitting an explicit indication indicating whether a RO from the plurality of ROs starting from the at least one SBFD time resource and ending in a non-SBFD time resource is valid.

42. The method as claimed in claim 41, wherein the RO is configured by the at least one second RACH configuration.

43. The method as claimed in claim 41, wherein the at least one second RACH configuration configures at least one parameter for the at least one SBFD time resource.

44. The method as claimed in claim 40, wherein identifying the best SSB beam comprises: mapping the plurality of valid ROs to the active SSB indices; and identifying at least one SSB beam corresponding to the valid RO.

45. The method as claimed in claim 44, further comprises: identifying the best SSB beam from the at least one SSB beam based on the RACH preamble and the at least one RACH configuration.

46. The method as claimed in claim 40, wherein the at least one SBFD time resource is a subset of the at least one time resource.

47. The method as claimed in claim 40, wherein a RO that starts from the at least one SBFD time resource and ends in a non-SBFD time resource is in the plurality of valid ROs when at least one of:a. the RO is within the frequency resources that are both in the at least one UL sub-band and active UL bandwidth part, b. the RO is configured by the at least one second RACH configuration for the at least one SBFD time resource, and c. the at least one first node receives an explicit indication.

48. The method as claimed in claim 40, wherein a RO from the plurality of valid ROs one of: is within the UL time resource, is within the frequency resources that are both in the at least one UL sub -band and active UL bandwidth part of the at least one SBFD time resource, and is in the frequency resources that are both in the at least one UL sub-band and active UL bandwidth part starting from the at least one SBFD time resource and ends in a non-SBFD time resource.

49. The method as claimed in claim 48, wherein the at least one SBFD time resource include the at least one time resource indicated as DL time resource by the at least one TDD configuration.

50. The method as claimed in claim 48, wherein the RO starting from the at least one SBFD time resource and ends in a non-SBFD time resource is valid only when a. the RO is configured by at least one second RACH configuration for the at least one SBFD time resource, and b. the at least one second node provides an explicit indication.

51. The method as claimed in claim 48, wherein, the RO starting from the at least one SBFD time resource and ends in a non-SBFD time resource comprises:at least one parameter for receiving the RACH preamble is same in the portion of the RO overlapping with the at least one SBFD time resource and the at least one non-SBFD time resource.

52. The method as claimed in claim 51, wherein the at least one parameter comprises at least one of: at least one frequency resource for reception, and a transmit power.

53. The method as claimed in claim 40, wherein transmitting the plurality of SSB beams, the at least one TDD configuration, the at least one RACH configuration, and the at least one SBFD configuration is one of: contiguously, and in intervals.

54. The method as claimed in claim 41, wherein transmitting the at least one first RACH configuration comprises transmitting at least one of: scheduling information of at least one first RO, an at least one first time resource, an at least one first frequency resource, an at least one first frequency offset, a total number of preambles per RO, a number of SSB s sharing a RO, a number of contention-based preambles per SSB per RO, a number of ROs multiplexed in frequency domain, and an at least one index from a predefined table.

55. The method as claimed in claim 41, wherein transmitting the at least one second RACH configuration comprises transmitting at least one of: scheduling information of at least one second RO, an at least one second time resource, an at least one second frequency resource, an at least one second frequency offset, a number of ROs multiplexed in frequency domain, at least one index from a predefined table, at least one offset, at least one scaling factor, a total number of preambles per RO for the at least one SBFD time resource, a number of SSBs sharing a RO for the at least one SBFD time resource, a priority of SSB indices for SSB-RO mapping in the at least one SBFD time resource, at least one SSB index for SSB-RO mapping in the at least one SBFD time resource, a number of contentions based preambles per SSB per RO for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, at least one RACH preamble for the at least one SBFD time resource, and at least one number.

56. The method as claimed in claim 55, wherein the at least one offset is at least one of frame offset, subframe offset, slot offset, symbol offset and a frequency offset.

57. The method as claimed in claim 55, wherein the at least one number is at least one of subframe number, slot number, and symbol number.

58. The method as claimed in at least one of claim 41, wherein the at least one frequency offset is the frequency offset of lowest RO in frequency domain with respective to one of: a lowest frequency resource in the UL sub band, a lowest frequency resource in the UL bandwidth part, and a lowest frequency resource from the frequency resources overlapping with the UL sub band and UL bandwidth part.

59. The method as claimed in claim 41, wherein the at least one frequency offset is applicable for at least one of: at least one RO in the at least one SBFD time resource, and at least one second RO.

60. The method as claimed in claim 40, wherein the plurality of ROs comprises: at least one first RO; and at least one second RO.

61. The method as claimed in at least one of claim 41 and claim 60, wherein the at least one first RO is in the at least one time resource configured as one of the UL time resource and the F time resource by the at least one TDD configuration.

62. The method as claimed in at least one of claim 41 and claim 60, wherein the at least one second RO is at least one of: within frequency resource that are both in the active UL bandwidth part and in the UL sub-band, within the at least one time resource configured as DL time resource by the at least one TDD configuration, andone of: within the at least one SBFD time resource, and across the at least one SBFD time resource and at least one non-SBFD time resource.

63. The method as claimed in claim 60, comprises at least one of: a. mapping the at least one first RO to the active SSB indices; and b. mapping the at least one second RO to the active SSB indices.

64. The method as claimed in claim 63, wherein mapping is based on at least one parameter configured by at least one first RACH configuration.

65. The method as claimed in claim 63, wherein a. mapping the at least one first RO is based on at least one parameter configured by at least one first RACH configuration; and b. mapping the at least one second RO is based on at least one parameter configured by at least one second RACH configuration.

66. The method as claimed in claim 63, further comprises at least one of: a. computing a first RACH association period for the at least one first RO, and b. computing a second RACH association period for the at least one second RO.

67. The method as claimed in claim 66, further comprises: a. computing a first RACH association pattern period based on the first RACH association period; and b. computing a second RACH association pattern period based on the second RACH association period.

68. The method as claimed in claim 66, further comprises:a. computing effective RACH association period as maximum of the first RACH association period and the second RACH association period; and b. computing effective RACH association pattern period based on the effective RACH association period.

69. The method as claimed in claim 66, wherein computing the first RACH association period further comprises: a. mapping the at least one second RO within the first RACH association period to the active SSB indices.

70. The method as claimed in claim 69, wherein mapping is one of: a. dividing the at least one second RO within the first RACH association period equally among the active SSB indices, b. based on at least one parameter configured by at least one first RACH configuration; and c. based on at least one parameter configured by at least one second RACH configuration.

71. The method as claimed in claim 41, wherein transmitting the second set of RACH preamble for the at least one SBFD time resource comprises transmitting at least one of: a. at least one root sequence, b. at least one cyclic shift, c. index of at least one non-RACH preamble, and d. index of at least one preamble from contention free preamble.

72. The method as claimed in claim 40, wherein identifying the best SSB beam comprises: identifying at least one of type of SSB-RO mapping and type of the at least one first node.

73. The method as claimed in claim 72, wherein type of the at least one first node comprises: a. legacy UE, andb. SBFD aware UE.

74. The method as claimed in claim 72, wherein type of the SSB-RO mapping comprises one of: a. SSB-RO mapping considering only at least one first RO, b. SSB-RO mapping considering only at least one second RO, and c. SSB-RO mapping considering both at least one first RO and at least one second RO.

75. The method as claimed in claim 72, wherein identifying comprises at least one of: identifying the at least one first node as SBFD aware UE, identifying the SSB-RO mapping include one of: at least one second RO only, and both at least one first RO and at least one second RO when at least one of the RACH preambles is from a second set of RACH preamble and the valid RO is from the at least one second RO.

76. The method as claimed in claim 75, wherein a. the second set of RACH preamble is configured for the at least one SBFD time resource, and b. the at least one second RO is configured for the at least one SBFD time resource.

77. The method as claimed in claim 40, wherein the at least one SBFD time resource is contiguous.

78. The method as claimed in claim 40, wherein the at least one SBFD time resource overlapping with at least one valid RO from the plurality of valid RO is treated as one of: a. the UE time resource, and b. a non-SBFD time resource.

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