WO2025171915A1

WO2025171915A1 - Random access

Info

Publication number: WO2025171915A1
Application number: PCT/EP2024/085596
Authority: WO
Inventors: Erika PORTELA LOPES DE ALMEIDA; Nhat-Quang NHAN; Karim KASAN; Juha Sakari Korhonen
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2024-02-16
Filing date: 2024-12-11
Publication date: 2025-08-21
Anticipated expiration: 2026-08-16

Abstract

According to an example aspect of the present invention, there is provided an apparatus configured to process, while in idle mode, information received from a network, the information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion and an extent of frequency multiplexing of the at least one RACH occasion, determine, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and initiate the random access procedure using at least one RACH occasion from among the set of RACH occasions.

Description

RANDOM ACCESS

FIELD

[001] The present disclosure relates to wireless cellular communication.

BACKGROUND

[002] Random access channel, RACH, processes, also known as random access processes, are used in wireless communication to access the communication network. For example, a user equipment, UE, in idle mode may use a random access process to request transition to connected mode with respect to the communication network. RACH processes may have, for example, two messaging steps or four messaging steps. A RACH process may be contention based, or contention free.

[003] A contention-based RACH process begins with the UE transmitting to the network an initial signal, such as a RACH preamble. The UE will transmit the initial signal using at least one RACH occasion, RO, which comprises time and frequency resources. The initial signal is sent using a physical random access channel, PRACH.

SUMMARY

[004] According to some aspects, there is provided the subject-matter of the independent claims. Some embodiments are defined in the dependent claims. The scope of protection sought for various embodiments of the invention is set out by the independent claims. The embodiments, examples and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the invention.

[005] According to a first aspect of the present disclosure, there is provided an apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to process, while in idle mode, information received from a network, the information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion and an extent of frequency multiplexing of the at least one RACH occasion, determine, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and initiate the random access procedure using at least one RACH occasion from among the set of RACH occasions.

[006] According to a second aspect of the present disclosure, there is provided an apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to broadcast in a cell controlled by the apparatus information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion, and an extent of frequency multiplexing of the at least one RACH occasion, and receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

[007] According to a third aspect of the present disclosure, there is provided a method comprising processing, by an apparatus and while in idle mode, information received from a network, the information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion and an extent of frequency multiplexing of the at least one RACH occasion, determining, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and initiating the random access procedure using at least one RACH occasion from among the set of RACH occasions.

[008] According to a fourth aspect of the present disclosure, there is provided a method comprising broadcasting, in a cell controlled by an apparatus performing the method, information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion and an extent of frequency multiplexing of the at least one RACH occasion, and receiving an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

[009] According to a fifth aspect of the present disclosure, there is provided a non- transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least process, while in idle mode, information received from a network, the information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion and an extent of frequency multiplexing of the at least one RACH occasion, determine, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and initiate the random access procedure using at least one RACH occasion from among the set of RACH occasions.

[0010] According to a sixth aspect of the present disclosure, there is provided a non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least broadcast in a cell controlled by the apparatus information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion, and an extent of frequency multiplexing of the at least one RACH occasion, and receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

[0011] According to a seventh aspect of the present disclosure, there is provided an apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to process, while in idle mode, information received from a network, the information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion and an extent of frequency multiplexing of the at least one RACH occasion by one of: 1) indicating a number of multiplexed RACH occasions in SBFD slots, or 2) a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots, and determine, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and initiate the random access procedure using at least one valid RACH occasion from among the set of RACH occasions.

[0012] According to an eighth aspect of the present disclosure, there is provided an apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to broadcast in a cell controlled by the apparatus information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion, and an extent of frequency multiplexing of the at least one RACH occasion by one of: 1) indicating a number of multiplexed RACH occasions in SBFD slots, or 2) a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots, and receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

[0013] According to a ninth aspect of the present disclosure, there is provided a method comprising processing, by an apparatus and while in idle mode, information received from a network, the information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion and an extent of frequency multiplexing of the at least one RACH occasion by one of: 1) indicating a number of multiplexed RACH occasions in SBFD slots, or 2) a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots, and determining, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and initiating the random access procedure using at least one valid RACH occasion from among the set of RACH occasions.

[0014] According to a tenth aspect of the present disclosure, there is provided a method comprising broadcasting, in a cell controlled by an apparatus performing the method, information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion and an extent of frequency multiplexing of the at least one RACH occasion by one of: 1) indicating a number of multiplexed RACH occasions in SBFD slots, or 2) a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots, and receiving an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

[0015] According to an eleventh aspect of the present disclosure, there is provided a non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least process, while in idle mode, information received from a network, the information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion and an extent of frequency multiplexing of the at least one RACH occasion by one of: 1) indicating a number of multiplexed RACH occasions in SBFD slots, or 2) a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots, and determine, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and initiate the random access procedure using at least one valid RACH occasion from among the set of RACH occasions.

[0016] According to a twelfth aspect of the present disclosure, there is provided a non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least broadcast in a cell controlled by the apparatus information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion, an extent of frequency multiplexing of the at least one RACH occasion by one of: 1) indicating a number of multiplexed RACH occasions in SBFD slots, or 2) a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots, and receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information. [0017] According to a thirteenth aspect of the present disclosure, there is provided an apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to process, while in idle mode, information received from a network, the information indicating frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and which slots from a sequence of subband non-overlapping full duplex, SBFD slots of the TDD carrier contain at least one random access channel, RACH, occasion, determine, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and initiate the random access procedure using at least one valid RACH occasion from among the set of RACH occasions.

[0018] According to a fourteenth aspect of the present disclosure, there is provided an apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to broadcast in a cell controlled by the apparatus information indicating a frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion, and receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

[0019] According to a fifteenth aspect of the present disclosure, there is provided a method comprising processing, by an apparatus and while in idle mode, information received from a network, the information indicating frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion, determining, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and initiating the random access procedure using at least one valid RACH occasion from among the set of RACH occasions. [0020] According to a sixteenth aspect of the present disclosure, there is provided a method comprising broadcasting, in a cell controlled by an apparatus performing the method, information indicating frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion, and receiving an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

[0021] According to a seventeenth aspect of the present disclosure, there is provided a non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least process, while in idle mode, information received from a network, the information indicating frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion, determine, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and initiate the random access procedure using at least one valid RACH occasion from among the set of RACH occasions.

[0022] According to an eighteenth aspect of the present disclosure, there is provided a non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least broadcast in a cell controlled by the apparatus information indicating frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion, and receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIGURE 1 illustrates an example system in accordance with at least some embodiments of the present invention;

[0024] FIGURE 2 illustrates duplexing schemes;

[0025] FIGURE 3 illustrates an example duplexing scenario in accordance with at least some embodiments of the present invention;

[0026] FIGURE 4 illustrates an example duplexing scenario in accordance with at least some embodiments of the present invention;

[0027] FIGURE 5 illustrates an example duplexing scenario in accordance with at least some embodiments of the present invention;

[0028] FIGURE 6 illustrates an example duplexing scenario in accordance with at least some embodiments of the present invention;

[0029] FIGURE 7 illustrates an example duplexing scenario in accordance with at least some embodiments of the present invention;

[0030] FIGURE 8 illustrates an example apparatus capable of supporting at least some embodiments of the present invention;

[0031] FIGURE 9 is a flowchart of a method in accordance with at least some embodiments of the present invention;

[0032] FIGURE 10 illustrates signalling in accordance with at least some embodiments of the present invention, and

[0033] FIGURES 11 - 16 are flow graphs of methods in accordance with at least some embodiments of the present invention.

EMBODIMENTS

[0034] Methods are herein described which enable efficient indication of RACH occasions, ROs, to UEs which are in idle mode. In these methods the network provides in broadcasted system information, a concise set of indications which enables an idlemode UE to determine a set of ROs in slots with subband non-overlapping full duplex, SBFD, symbols. Such slots are referred to herein as SBFD slots, and all of their symbols are SBFD symbols. The concise set of indications enables the UE to determine a set of ROs that it may use, such that at least some of these ROs are in SBFD slots on SBFD symbols. The UE may be aware or unaware that the slots are SBFD slots. The concise indication enables a reduced size of the information provided from base stations to UEs in idle mode, which saves energy and results in a technical benefit in terms of a reduced energy consumption rate of the network.

[0035] By SBFD symbols it is meant symbols with uplink, UL, and downlink, DL, subbands that a base station operates within a time-division duplex, TDD, carrier. During SBFD symbols the network simultaneously transmits in the DL and receives in the UL using unpaired frequency bands, such as in a TDD carrier.

[0036] For an SBFD aware UE, the SBFD symbol contains a DL subband and an UL subband, therefore some extension on the legacy indications may be used for the UE to be able to locate the ROs in SBFD symbols. Let us consider a scenario where the ROs do not overlap with the SBFD UL subbands due to applying the legacy time and frequency configurations RACH-ConfigGeneric designed for UL-only symbols on the SBFD symbols. Accordingly, since the ROs are not contained in the UL subband of the SBFD symbol, the ROs should not be deemed valid. Additional indications from the network to the UE may be considered to assist in locating the ROs on SBFD symbols. This can be done, for example, by signaling SBFD RACH indications to be used by SBFD-aware UEs to perform random access in SBFD symbols. These indications may be signaled, for example, via RACH-ConfigGeneric embedded in RACH-ConfigCommon in the ServingCellConfigCommonSIB for RRC-Idle mode, or those indication may be signaled in a dedicated RRC message for RRC-Connected mode UEs. The UE may implicitly assume that the received SBFD RACH indications apply to ROs colliding or overlapping with SBFD symbols, e.g. SBFD UL subband. ROs overlapping with SBFD UL subband may be considered as valid ROs or deemed as valid. Alternatively, an explicit indication of the valid ROs can be included in the SBFD RACH configuration.

[0037] Implicit and/or explicit indication(s) to assist the UE on locating the ROs on SBFD symbols in time and frequency are disclosed herein. In addition, these indications inform the UE performing the initial access using the ROs on SBFD symbols that the cell supports SBFD operation and the SBFD aware UE will be able to use the validated ROs according to the configuration indicative of the indications. These indications for locating the ROs on SBFD slots assist the SBFD-aware UEs on identifying an SBFD-capable cell.

[0038] In paired spectrum, all ROs are valid. In unpaired spectrum, ROs are valid if the UE is not provided a tdd-UL-DL-ConfigurationCommon, and there is a sufficient gap between the PRACH occasion, and the SSB symbols, or: the UE is provided a tdd- UL-DL-ConfigurationCommon, and the PRACH occasion is within UL symbols, or there is sufficient gap between (1) the PRACH occasion and SSB symbols and (2) the PRACH occasion start and the last DL symbol.

[0039] SBFD aware UE may be aware of the time and frequency configurations of SBFD at least in RRC connected mode. However, in RRC idle mode or inactive mode, the UE might not be aware of the time and frequency configurations of SBFD. In case the time and frequency configurations of SBFD are not included in SIB for RRC IDLE or RRC INACTIVE modes, a minimum information at least on which ROs in DL symbols (SBFD symbols are seen as DL symbols by the UE before being in connected mode) are valid may be conveyed to SBFD-aware UE. In case the time and frequency configurations of SBFD are included in SIB for RRC IDLE or RRC INACTIVE modes, it may be considered that the ROs in SBFD symbols and in UL sub-band are valid for SBFD-aware UE. However, in SBFD symbols, apart from the time domain aspect, it may be possible that not all resources within the UL sub-band are available for PRACH transmission. This may help gNB to control the resources and reduce complexity when needed.

[0040] FIGURE 1 illustrates an example system in accordance with at least some embodiments of the present invention. This system includes base stations 130, 135 in communication with UEs, such as UE 110. A radio link connects base station 130 with UE 110. The radio link may be bidirectional, comprising an uplink, UL, to convey information from UE 110 toward base station 130, and a downlink, DL, to convey information from the base station 130 toward UE 110. A cellular communication system may comprise hundreds or thousands of base stations, of which only two are illustrated in FIGURE 1 for the sake of clarity of the illustration. The base stations may be distributed in that they comprise a centralized unit, CU, and one or more distributed unit, DU. A base station is an example of a base node. [0041] Base station 130 is further coupled communicatively with core network node 140, which may comprise, for example, a mobility management entity, MME, or access and mobility management function, AMF. The core network node 140 may be coupled with further core network nodes, and with a network 150, which may comprise the Internet or a corporate network, for example. The system may communicate with further networks via network 150. Examples of the further core network nodes, which are not illustrated in FIGURE 1 for the sake of clarity, include gateways and subscriber information repositories. Core network nodes may be virtualized in the sense that they may run as software modules on computing substrates, such that more than one virtualized network node may run on a same computing substrate. The network may be configured to function in accordance with a suitable cellular standard such as long term evolution, LTE, fifth generation, 5G, which is also known as New Radio, NR, or sixth generation, 6G standards as defined by the the 3^rd generation partnership project, 3GPP.

[0042] Base station 130 controls, in the example of FIGURE 1 cells 130A and 130B, of which UE 110 is in the situation illustrated in FIGURE 1 attached with cell 130A, and base station 135 controls, in the example of FIGURE 1, cells 135A and 135B. The number of cells, or beams, may be in excess of what is illustrated in FIGURE 1. It is also possible that a base station has a single cell or beam. While illustrated as sectorshaped, cells of a same base station may be omnidirectional and operate on different frequencies, for example. A mobility event may comprise a switch from one beam to another beam of the same cell, or a switch from one cell to another cell. To support mobility procedures, UEs, including UE 110, are configured to conduct mobility measurements to measure signal strengths of adjacent beams and/or cells, and report results of these measurements to the network, which may then take a decision concerning a mobility event, such as a beam change or a cell switch.

[0043] When a UE, such as UE 110, is in idle mode, its connection with the radioaccess network, RAN, is closed. An idle-mode UE may be identified by non-access stratum, NAS, identities. Further, the RAN has no information of its own concerning idlemode UEs and base stations of a RAN can only address idle mode UEs in a cell by broadcasting information or sending paging messages during paging occasions. Further, base stations of the RAN do not store a UE context of an idle-mode UE and there is no NAS signalling connection between the idle mode UE and the network. A UE context, stored by the base station for connected mode UEs, comprises associations between the UE and identities of logical connections used for messages associated with this UE. The

UE context is, in other words, needed to maintain active RAN services toward the UE.

[0044] In time-division duplex, TDD, the same frequency resources are used alternatingly for UL and DL communication while frequency-division duplex, FDD, involves using separate frequency resources for UL and DL at the same time, enabling simultaneous UL and DL communication. The frequency resources of FDD carriers are thus paired to form a bidirectional connection. A TDD carrier will use the same block of spectrum for UL and DL, at different times.

[0045] Subband non-overlapping full duplex, SBFD, involves simultaneous UL and DL communication in a TDD carrier, such that frequency resources are split into an UL subband, a DL subband and possibly a guard band therebetween. SBFD may last for a single slot, more than one contiguous slot or for individual symbols, or subsets of symbols, within slots. A slot with at least one SBFD symbol will herein be referred to as an SBFD slot. A flexible slot includes flexible symbols, each of which may be scheduled as an UL-direction symbol or a DL-direction symbol without simultaneous UL and DL communication. A special slot comprises a guard period between UL and DL transmission.

[0046] FIGURE 2 illustrates duplexing schemes. Frequency is on the vertical axes and time on the horizontal axes. On the top left, FDD duplexing is illustrated, wherein a guard band in frequency domain separates the paired uplink and downlink frequency resources. On the top right, TDD duplexing is illustrated, wherein the same frequency resources are used in the UL and DL directions, but at different times. Finally, in the lower figure, SBFD duplexing is used, wherein at least some of the time UL and DL communication takes place at the same time, using a TDD carrier and unpaired frequency resources. This is accomplished by using, for some or all symbols of an SBFD slot, subbands for UL and DL, with a guard band thereinbetween. In the example of FIGURE 2, the subbands are not constant but change over time, for example from one SBFD symbol to another. An SBFD time and frequency domain configuration defines the symbols and/or slots when SBFD is used, and the subbands for UL and DL during this time, or these times. Other names for SBFD include cross-division duplexing, xDD, and flexible duplexing, FDU. [0047] An RO is an opportunity for the UE to transmit a RA preamble in the uplink direction, wherefore in TDD in principle ROs are in uplink slots. However, in the case of SBFD slots it is possible for ROs to exist in the UL subband of these slots since UL communication is possible in these slots. A UE in idle mode may be unaware of an SBFD time and frequency configuration active in a cell, wherefore informing such UEs of ROs in SBFD slots presents a challenge. Herein are described indication methods to accomplish informing an idle-mode UE of ROs in SBFD slots without communication the whole SBFD time and frequency configuration before the UE is transitioned to connected mode. These methods communicate less than the whole SBFD time and frequency configuration to enable the UE to use the SBFD-slot ROs without necessarily knowing details of the SBFD configuration. For example, the UE may be left un-informed of the subbands for UL and DL during SBFD, since the UE doesn’t need to know what the DL subband is, for example, or what is the entire extent of the UL subband, to use ROs in the UL subband of an SBFD slot.

[0048] For the system to work correctly, the ROs indicated to the UE should overlap an UL subband of the SBFD slot(s) since the network will not be listening to UL transmission on the DL subband, or on a guard band separating the UL and DL subbands.

[0049] In principle, there are several manners in which the network may inform the UE of ROs in SBFD slots. In a solution which relies on a lot of broadcasted information, time and frequency domain allocations of all ROs may be sent to the UE explicitly. Further, alternatively or in addition, the base station may inform the idle mode UE concerning which slots in a TDD slot sequence are SBFD slots, and/or define the UL/DL subbands in the frequency domain in these SBFD slots. This information together, namely the information on which slots of a TDD slot sequence are SBFD slots and the UL/DL subband indications, forms an SBFD configuration, also known as an SBFD time and frequency configuration.

[0050] The network, for example a base station controlling a cell, may provide to a UE information on SBFD in two stages, for example in case SBFD-slot ROs are not defined explicitly and/or the SBFD configuration is not provided to the UE. Firstly, the base station may provide limited and incomplete information, which is sufficient for the UE to determine a set of ROs in SBFD slots to use in a RA process, and secondly, when the UE is, as a consequence of the RA process, in the connected mode, the base station may provide the whole SBFD time and frequency configuration. For example, the first phase may omit informing the idle mode UE of the UL and DL subbands in SBFD slots, and the second phase may then comprise informing the UE, by this time in connected mode, of these. The first phase indicates to the UE time and frequency locations of ROs in the SBFD slots, which is all the UE needs to know to use these ROs.

[0051] In the first phase, there is more than one way to indicate the time and frequency locations of the ROs in the SBFD slots. Concerning first the indication of the locations of these ROs in the time domain, in terms of which slots comprise them, there are three main alternatives. Firstly, the UE may be configured to assume that a preconfigured number of slots before a first flexible or UL slot in a TDD pattern are valid for PRACH transmissions. The preconfigured number, for example one, may be either configured by the network, or specified in the specification (pre-configured). Secondly, the UE may be configured to determine that all slots between a reference slot and a last UL or flexible slot are valid for PRACH, and thirdly, the base station may provide to the UE a bitmap which indicates which slots in a TDD slot pattern are valid for PRACH. Herein being valid for PRACH means that such slot has at least one RO overlapping with the UL subband. RO overlapping with the UL subband may be referred to as a valid RO. A valid slot comprises at least one valid RO. By a valid RO it is meant a RO which the UE considers valid and may consider using.

[0052] Further in the first phase, there are also different ways to indicate where the SBFD-slot ROs are in the frequency domain, this involving indicating a frequency at which the ROs start, and an extent to which the ROs are frequency multiplexed. Concerning first the indication of frequency start, a first option is for the base station to provide to the UE a frequency offset from a beginning (initial), center or end of the used frequency band on the carrier to a start, midpoint or end of the UL subband or RO group in the SBFD slots. In general the frequency offset may be defined from a reference frequency. The beginning, or initial, frequency may alternatively be referred to as a start frequency, A second option is to provide a frequency offset from a start, center or end frequency of a group of ROs in an UL slot to a start frequency of RO or a group of ROs in an SBFD slot. The UE may apply this frequency offset to a signaling message (for example msg 1 -Frequency Start) value indicating UL-slot RO start frequency, received in system information block, SIB, to derive a frequency start of the RO allocation in SBFD symbols. A third option is to provide the UE with an SBFD-specific indication of RO start in frequency domain, for example as an msgl-FrequencyStart-SBFD indication in the case of 5G.

[0053] Concerning the indication of the extent of multiplexing in the first phase, there are at least two alternative options. According to the first one, the base station provides to the UE a multiplexing configuration applicable to SBFD symbols or slots, and according to a second one, the base station provides to the UE a bitmap which indicates which ROs of the UL-slot ROs are also valid at a different time instance in SBFD slots. A bit width of the bitmap may be equal to a multiplexing indication relating to ROs in an UL slot.

[0054] Certain special cases are possible. For example, when the UE is not provided with an indication of which SBFD slots comprise ROs, the UE may be configured to consider only UL-slot ROs as being valid. Likewise, if no frequency domain indications for SBFD-slot ROs are provided, the UE may determine that SBFD slots have ROs in the same frequency locations as an UL slot does. This corresponds to the case where frequency domain locations of ROs in an UL slot and in an SBFD slot are the same. Frequency domain allocation may be indicative of frequency domain locations of ROs. For example, the frequency domain allocation may be indicative of the start frequency value of the ROs and the multiplexing factor.

[0055] These indications will now be described in more detail. Concerning the first manner of indicating which slots have SBFD ROs, as noted above the UE may be configured to consider that a predetermined number of slots before an uplink, or flexible, slot contain ROs the idle mode UE may use. In other words, the ROs which overlap with these predetermined number of slots are also valid regardless of the slot type. The predetermined number may be configured in SIB1 or specified in specification. For example, it may be equal to one or two. When the UE is later in connected mode, it may be configured with a number of SBFD slots that could be greater than or equal to the predetermined number.

[0056] Concerning the second manner of indicating which slots have SBFD ROs, as noted above the UE may be configured to determine that all slots between a reference slot and a last UL or flexible slot are valid for PRACH. The reference slot, which may be a DL slot, may be fixed in industry specifications, for example it may be the first, or the last DL (or flexible) slot in a TDD slot sequence. For example, a slot sequence: DDDSU with a reference slot being the first DL slot in the pattern; the new slot pattern will be

DNNNU, where N here is considered as the new valid PRACH slots.

[0057] Concerning the third manner of indicating which slots have SBFD ROs, as noted above the UE may be configured with a bitmap which indicates which slots in a TDD slot pattern are valid for PRACH. The bitmap indication may override a slot pattern provided by a message or information element TDD-UL-DL-ConfigCommon. For example, in the case of a TDD slot sequence DDDSU and an indicated bitmap 01100, the idle mode UE may determine that the new slot pattern will be DNNSU, where N here is considered the new valid PRACH slots. In another example, the length of the bitmap corresponds to the number of downlink, D, slots or the number of D slots after the first D slot in the TDD slot sequence.

[0058] Turning next to the indication of frequencies of the SBFD-slot ROs, if the UE does not get any new information regarding the frequency start in SBFD symbols, it may assume that the same configuration as in UL symbols is valid in SBFD symbols too, and skips this step. It may also be assumed that the UE gets information about the frequency domain resource allocation for ROs in UL slots/symbols and derives the frequency domain resource allocation for ROs in SBFD symbols based on additional information received from the network.

[0059] As noted above, concerning the indication of start frequency of the SBFD slot ROs, the base station may provide to the UE a frequency offset from a beginning, center or end of the used frequency band on the carrier to a start, midpoint or end of the UL subband in the SBFD slots. For example, the UE may receive from the network an indication of whether the UL subband is configured in the edge or center of the carrier. For example, the UL subband may be indicated as being in the lower edge, center or upper edge of the carrier. This can be indicated using two bits in broadcasted information, for example: 00 indicating a lower edge, 01 indicating the center and 10 indicating an upper edge. The UE may then determine how the frequency resources for the ROs in SBFD symbols are mapped, based on the configuration of the ROs in UL symbols. The determination may be either fixed in the specification, that is, a pre-defined frequency offset to be applied to a reference RB in the BWP, depending on the location indication, such as: the first RB in the Initial BWP (lower edge), last RB in the Initial BWP (upper edge) or the center RB in the initial BWP (center). Alternatively the gNB may configure a frequency offset. [0060] A second option for the indication of start frequency of the SBFD slot ROs is to provide a frequency offset from a group of ROs in an UL slot to ROs in an SBFD slot. The UE may apply this frequency offset to the value of msgl-FrequencyStart, received in system information block, SIB, to derive a frequency start of the RO allocation in SBFD symbols, for example, in the case of 5G. The offset may be to a higher frequency when the UL subband is in a higher frequency range than the ROs in the UL slot, and to a lower frequency when the UL subband (and its ROs) is in a lower frequency range than the ROs in the UL slot. The offset may be provided in terms of a number of frequency resources, for example.

[0061] A third option for the indication of start frequency of the SBFD slot ROs is to provide the UE with an SBFD-specific indication of RO start in frequency domain, for example as an msgl -Frequency Start- SBFD indication in the case of 5G. This enables indicating the frequency start independently of the ROs in the UL slot.

[0062] Turning next to the indication of the extent of frequency division multiplexing (FDM) of the SBFD slot ROs, as noted above, this may be accomplished by the base station providing to the UE a multiplexing configuration applicable to SBFD symbols or slots. This configuration may be, in the case of 5G, an MSG1-FDM-SBFD configuration concerning only the number of ROs in the UL subband of the SBFD slots, and a separate Msgl -FDM may convey the number of ROs frequency multiplexed in UL- only non- SBFD slots.

[0063] A second option for the indication of the extent of frequency multiplexing of the SBFD slot ROs, as noted above, is the base station providing to the UE a bitmap which indicates which ROs of the UL-slot ROs are valid at a time instance in SBFD slot(s). The bitmap may have the same width as Msgl -FDM, or in general a message defining frequency multiplexing of ROs in UL-only slots. The least significant bit in the bitmap may correspond to the RO mapped to the lowest frequency, for example. The network may ensure by implementation that at least one RO in the Msgl -FDM frequency multiplexed ROs overlaps with a UL subband. For example, the bandwidth occupied by the UL-slot ROs may be larger than the UL subband. In this case, the ROs located outside of the UL subband in frequency domain may be indicated by 0 in the bitmap, and the ROs overlapping with the UL subband in frequency domain may be indicated by 1 in the bitmap. Then, the ROs indicated by 1 are valid Msgl-FDM ROs in the UL subband. [0064] If the UE does not receive new information regarding the frequency domain multiplexing in SBFD symbols, it may be configured to assume that the same configuration as is used in multiplexing ROs in UL symbols is valid in SBFD symbols.

[0065] FIGURE 3 illustrates an example duplexing scenario in accordance with at least some embodiments of the present invention. In FIGURE 3, time is on the horizontal axis and frequency is on the vertical axis as in the plots of FIGURE 2. In this figure, the first slots on the left are DL slots, the slots in the middle are SBFD slots and the last two slots on the right are UL slots, as indicated by the hatching. The smaller rectangles are ROs. ROs in the UL slots may be indicated to the UE using customary indication methods, such as broadcasted information, or the UE may know these ROs from network-wide configuration information, for example.

[0066] Slots 310 are SBFD slots wherein are found at least one RO in the UL subband. Indicating these slots to the UE amounts to indicating valid SBFD ROs in the time domain. Valid SBFD ROs are ROs overlapping with the UL subband. Frequency domain allocation 320 represents an extent in frequency domain of valid ROs in SBFD slots which are available to the UE. In the case of FIGURE 3, the base station does not inform idle-mode UEs which slots are SBFD slots, and neither does the base station inform idle-mode UEs of the frequency domain allocation of SBFD subbands, e.g. of the edges of UL and DL subbands in SBFD. However, the base station does inform the idlemode UEs of the time and frequency domain allocations of ROs valid in SBFD slots. In FIGURE 3, for example, the UE may be informed that the last two slots before an uplink slot have valid ROs, that the lower frequency bound of these valid ROs starts from the same frequency as the ROs in the UL slot, that is, a frequency offset between UL and SBFD slot ROs is zero, and that SBFD slot ROs are frequency multiplexed by a factor of three. As an alternative of informing the multiplexing of the SBFD slot ROs, the UE may be informed that the UL ROs are multiplexed by a factor of four and the valid ROs for SBFD slots may be indicated with a bitmap 0111. This information is enough for the UE to determine the valid non-UL slot ROs, shaded black in FIGURE 3. The UE may then use one of these ROs to initiate a RA process with the base station.

[0067] FIGURE 4 illustrates an example duplexing scenario in accordance with at least some embodiments of the present invention. Like numbering and hatching denotes like structure as in FIGURE 3. The case of FIGURE 4 differs from that in FIGURE 3 in that the base station only provides to the UE information concerning which slots have SBFD ROs, the base station does not define where in frequency domain these ROs are to be found. The UE is configured to, in this situation, re-use the frequency allocation of ROs in the UL (or flexible) slot, which is in this case appropriate since these ROs fall on the UL subband of the SBFD slots. The UE need not know the upper or lower edge of the UL subband to use these ROs, the implicit indication of the location of the ROs in frequency domain is enough. Conserving the indication results in conserved energy, a major consideration in operating wireless communication networks.

[0068] FIGURE 5 illustrates an example duplexing scenario in accordance with at least some embodiments of the present invention. This scenario resembles that in FIGURE 3, however here the base station is configured to include in broadcasted information provided to idle mode UEs also the definition of which slots of the TDD pattern areSBFD slots 510, and the definition of the UL subband of these slots 520. While this results in an increased broadcast signalling burden, it provides the benefit of a simpler implementation on the base station side.

[0069] FIGURE 6 illustrates an example duplexing scenario in accordance with at least some embodiments of the present invention. This scenario resembles that in FIGURE 5, however with the difference that unlike in the scenario of FIGURE 5, the frequency allocation of the SBFD slot ROs is not indicated to the idle mode UE, which is then configured to assume that the same frequency allocation of ROs as is present in the UL slot is also applied to SBFD slots with ROs - which is in this case appropriate, as such ROs fall within the SBFD slot UL subband. As was the case in FIGURE 5, the SBFD configuration is provided to idle mode UEs in broadcasted information, including both the knowledge of which slots in the TDD slot sequence are SBFD slots and the SBFD UL subband in these slots.

[0070] FIGURE 7 illustrates an example duplexing scenario in accordance with at least some embodiments of the present invention. In this scenario, as in those of FIGURES 5 and 6, the base station is configured to include in broadcasted information provided to idle mode UEs the definition of which slots of the TDD pattern areSBFD slots 510, and the definition of the UL subband of these slots 520. In addition, the frequency allocation 320 of the SBFD slot ROs is provided to idle mode UEs. The UE may in such a situation assume, that SBFD slot ROs are present in all SBFD slots within the defined frequency range 320, and select at least one of these ROs in the UL slot(s), for a RA process. [0071] Thus overall the following kinds of configurations may be envisaged with reference to FIGURES 3 - 7 :

1) Time domain allocation of all ROs (UE applies TDD slot sequence to determine valid ROs)

2) Frequency domain allocation of all ROs

3) Time domain allocation of SBFD slots (indication of which slots are SBFD slots)

4) Frequency domain allocation of SBFD subbands

5) Time domain allocation of slots, in which ROs are valid for SBFD-aware UE

6) Frequency domain allocation for determining which ROs in the slots indicated in 3 and/or 5 can be considered as valid RO for SBFD-aware UE

[0072] Thus in the scenario of FIGURE 3, both 5 and 6 of the above are configured without 1 - 2 or 3 - 4. In the scenario of FIGURE 4, only 5 is configured, without 1 - 2 or 3 - 4 or 6. In the scenario of FIGURE 5 only configurations 3, 4, 5 and 6 are sent to idle mode UE. In the scenario of FIGURE 6, only configurations 3, 4 and 5 are sent to idle mode UE and in the scenario of FIGURE 7, only configurations 3, 4 and 6 are sent to the idle mode UE.

[0073] FIGURE 8 illustrates an example apparatus capable of supporting at least some embodiments of the present invention. Illustrated is device 800, which may comprise, for example, a mobile communication device such as UE 110 of FIGURE 1. Comprised in device 800 is processor 810, which may comprise, for example, a single- or multi-core processor wherein a single-core processor comprises one processing core and a multi-core processor comprises more than one processing core. Processor 810 may comprise, in general, a control device. Processor 810 may comprise more than one processor. When processor 810 comprises more than one processor, device 800 may be a distributed device wherein processing of tasks takes place in more than one physical unit. Processor 810 may be a control device. A processing core may comprise, for example, a Cortex-A8 processing core manufactured by ARM Holdings or a Zen processing core designed by Advanced Micro Devices Corporation. A processing core or processor may be, or may comprise, at least one qubit. Processor 810 may comprise at least one Qualcomm Snapdragon and/or Intel Atom processor. Processor 810 may comprise at least one application-specific integrated circuit, ASIC. Processor 810 may comprise at least one field-programmable gate array, FPGA. Processor 810, optionally together with memory and computer instructions, may be means for performing method steps in device 800, such as processing, determining, initiating, broadcasting and receiving. Processor 810 may be configured, at least in part by computer instructions, to perform actions.

[0074] A processor may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with embodiments described herein. As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in only analogue and/or digital circuitry, and (b) combinations of hardware circuits and software, such as, as applicable: (i) a combination of analogue and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a UE or base station, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor s) or a portion of a microprocessor s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0075] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0076] Device 800 may comprise memory 820. Memory 820 may comprise random-access memory and/or permanent memory. Memory 820 may comprise at least one RAM chip. Memory 820 may be a computer readable medium. Memory 820 may comprise solid-state, magnetic, optical and/or holographic memory, for example. Memory 820 may be at least in part accessible to processor 810. Memory 820 may be at least in part comprised in processor 810. Memory 820 may be means for storing information. Memory 820 may comprise computer instructions that processor 810 is configured to execute. When computer instructions configured to cause processor 810 to perform certain actions are stored in memory 820, and device 800 overall is configured to run under the direction of processor 810 using computer instructions from memory 820, processor 810 and/or its at least one processing core may be considered to be configured to perform said certain actions. Memory 820 may be at least in part external to device 800 but accessible to device 800. Memory 820 may be transitory or non- transitory. The term “non-transitory”, as used herein, is a limitation of the medium itself (that is, tangible, not a signal) as opposed to a limitation on data storage persistency (for example, RAM vs. ROM).

[0077] Device 800 may comprise a transmitter 830. Device 800 may comprise a receiver 840. Transmitter 830 and receiver 840 may be configured to transmit and receive, respectively, information in accordance with at least one cellular or non-cellular standard. Transmitter 830 may comprise more than one transmitter. Receiver 840 may comprise more than one receiver. Transmitter 830 and/or receiver 840 may be configured to operate in accordance with global system for mobile communication, GSM, wideband code division multiple access, WCDMA, 5G, long term evolution, LTE, IS-95, wireless local area network, WLAN, Ethernet and/or worldwide interoperability for microwave access, WiMAX, standards, for example.

[0078] Device 800 may comprise a near-field communication, NFC, transceiver 850. NFC transceiver 850 may support at least one NFC technology, such as NFC, Bluetooth, Wibree or similar technologies.

[0079] Device 800 may comprise user interface, UI, 860. UI 860 may comprise at least one of a display, a keyboard, a touchscreen, a vibrator arranged to signal to a user by causing device 800 to vibrate, a speaker or a microphone. A user may be able to operate device 800 via UI 860, for example to accept incoming telephone calls, to originate telephone calls or video calls, to browse the Internet, to manage digital files stored in memory 820 or on a cloud accessible via transmitter 830 and receiver 840, or via NFC transceiver 850, and/or to play games.

[0080] Device 800 may comprise or be arranged to accept a user identity module 870. User identity module 870 may comprise, for example, a subscriber identity module, SIM, card installable in device 800. A user identity module 870 may comprise information identifying a subscription of a user of device 800. A user identity module 870 may comprise cryptographic information usable to verify the identity of a user of device 800 and/or to facilitate encryption of communicated information and billing of the user of device 800 for communication effected via device 800.

[0081] Processor 810 may be furnished with a transmitter arranged to output information from processor 810, via electrical leads internal to device 800, to other devices comprised in device 800. Such a transmitter may comprise a serial bus transmitter arranged to, for example, output information via at least one electrical lead to memory 820 for storage therein. Alternatively to a serial bus, the transmitter may comprise a parallel bus transmitter. Likewise processor 810 may comprise a receiver arranged to receive information in processor 810, via electrical leads internal to device 800, from other devices comprised in device 800. Such a receiver may comprise a serial bus receiver arranged to, for example, receive information via at least one electrical lead from receiver 840 for processing in processor 810. Alternatively to a serial bus, the receiver may comprise a parallel bus receiver.

[0082] Device 800 may comprise further devices not illustrated in FIGURE 8. For example, where device 800 comprises a smartphone, it may comprise at least one digital camera. Some devices 800 may comprise a back-facing camera and a front-facing camera, wherein the back-facing camera may be intended for digital photography and the frontfacing camera for video telephony. Device 800 may comprise a fingerprint sensor arranged to authenticate, at least in part, a user of device 800. In some embodiments, device 800 lacks at least one device described above. For example, some devices 800 may lack a NFC transceiver 850 and/or user identity module 870.

[0083] Processor 810, memory 820, transmitter 830, receiver 840, NFC transceiver 850, UI 860 and/or user identity module 870 may be interconnected by electrical leads internal to device 800 in a multitude of different ways. For example, each of the aforementioned devices may be separately connected to a master bus internal to device 800, to allow for the devices to exchange information. However, as the skilled person will appreciate, this is only one example and depending on the embodiment various ways of interconnecting at least two of the aforementioned devices may be selected without departing from the scope of the present invention.

[0084] FIGURE 9 is a flowchart of a method in accordance with at least some embodiments of the present invention. The method may be performed by a UE, for example, or a controller, such as a chipset or processor, of a UE. In phase 910, the UE performs synchronization with a base station and reading of broadcasted system information. Processing advances to phase 920 where it is determined, if the system information contains indications for ROs at an UL subband in an SBFD slot. If this is not the case, processing advances via phase 930 and legacy processing to phase 960, where the SBFD configuration is provided to the UE after it has transitioned to connected mode.

[0085] However if it is in phase 920 determined that the system information does contain information on UL subband ROs, processing advances from phase 920 to phase 940, where the time and frequency locations of the UL subband, that is SBFD-slot, ROs are determined based at least in part on the information broadcasted by the base station and read by the idle mode UE in phase 910. Subsequently, in phase 950, a random access process is performed, the random access process being initiated using at least one of the UL subband ROs. In some examples, the UE may initiate the random access process using a next available or next possible RO. The next available RO may be a legacy UL RO, or an SBFD slot RO. Finally, after the random access process, the UE being in connected mode, the base station provides the SBFD configuration including the definitions of the UL subband and DL subband. The SBFD configuration may be referred to as a full SBFD configuration.

[0086] FIGURE 10 is a signalling diagram in accordance with at least some embodiments of the present invention. On the vertical axes are disposed, on the left, UE 110 of FIGURE 1, and on the right, a base station 130. Time advances from the top toward the bottom.

[0087] In phase 1010, base station 1030 broadcasts system information which comprises indications relating to the SBFD slot ROs, which have been described herein above. In phase 1020, idle mode UE 110 determines, based on the indications in the broadcasted system information, a set of SBFD slot ROs, as described herein above. The set of SBFD slot ROs may comprise one or more ROs. The set may comprise one RO. The set may comprise a plurality of ROs.

[0088] In phase 1030 UE 110 initiates an RA process by transmitting a RA preamble in one of the ROs, for example, in an SBFD slot RO. In some examples, the UE may initiate the RA process using a next available or next possible RO. The next available RO may be a legacy UL RO, or the SBFD slot RO. The examined RA process of FIGURE 10 is a four-step RA process, comprising a random access response 1040 from base station 130, a radio resource control, RRC, request 1050 from UE 110 and finally a RRC setup message 1060 from base station 130 to UE 110.

[0089] FIGURE 11 is a flow graph of a method in accordance with at least some embodiments of the present invention. The phases of the illustrated method may be performed in UE 110, or in a control device configured to control the functioning thereof, when installed therein.

[0090] Phase 1110 comprises processing, by an apparatus and while in idle mode, information received from a network, the information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion, and an extent of frequency multiplexing of the at least one RACH occasion. Phase 1120 comprises determining, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, Phase 1130 comprises initiating the random access procedure using at least one RACH occasion from among the set of RACH occasions.

[0091] FIGURE 12 is a flow graph of a method in accordance with at least some embodiments of the present invention. The phases of the illustrated method may be performed in base station 130, or in a control device configured to control the functioning thereof, when installed therein.

[0092] Phase 1210 comprises broadcasting, in a cell controlled by an apparatus performing the method, information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion, and an extent of frequency multiplexing of the at least one RACH occasion. Phase 1220 comprises receiving an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information. The method may further comprise completing a random access process with the UE, the random access process being initiated by the initial random access signal.

[0093] FIGURE 13 is a flow graph of a method in accordance with at least some embodiments of the present invention. The phases of the illustrated method may be performed in UE 110, or in a control device configured to control the functioning thereof, when installed therein.

[0094] Phase 1310 comprises processing, by an apparatus and while in idle mode, information received from a network, the information indicating: which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion; and an extent of frequency multiplexing of the at least one RACH occasion by one of 1) indicating a number of multiplexed RACH occasions in SBFD slots, or 2) a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots. Phase 1320 comprises determining, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband. Phase 1330 comprises initiating the random access procedure using at least one valid RACH occasion from among the set of RACH occasions.

[0095] FIGURE 14 is a flow graph of a method in accordance with at least some embodiments of the present invention. The phases of the illustrated method may be performed in base station 130, or in a control device configured to control the functioning thereof, when installed therein.

[0096] Phase 1410 comprises broadcasting, in a cell controlled by an apparatus performing the method, information indicating which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion, a frequency start value of the at least one RACH occasion; and an extent of frequency multiplexing of the at least one RACH occasion by one of 1) indicating a number of multiplexed RACH occasions in SBFD slots, or 2) a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots. Phase 1420 comprises receiving an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information. [0097] FIGURE 15 is a flow graph of a method in accordance with at least some embodiments of the present invention. The phases of the illustrated method may be performed in UE 110, or in a control device configured to control the functioning thereof, when installed therein. [0098] Phase 1510 comprises processing, by an apparatus and while in idle mode, information received from a network, the information indicating frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion. Phase 1520 comprises determining, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband. Phase 1530 comprises initiating the random access procedure using at least one valid RACH occasion from among the set of RACH occasions.

[0099] FIGURE 16 is a flow graph of a method in accordance with at least some embodiments of the present invention. The phases of the illustrated method may be performed in base station 130, or in a control device configured to control the functioning thereof, when installed therein.

[00100] Phase 1610 comprises broadcasting, in a cell controlled by an apparatus performing the method, information indicating frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and which slots from a sequence of subband nonoverlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion. Finally, phase 1620 comprises receiving an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

[00101] It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting.

[00102] Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Where reference is made to a numerical value using a term such as, for example, about or substantially, the exact numerical value is also disclosed.

[00103] As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.

[00104] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the preceding description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

[00105] While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.

[00106] The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of "a" or "an", that is, a singular form, throughout this document does not exclude a plurality.

[00107] As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

INDUSTRIAL APPLICABILITY

[00108] At least some embodiments of the present invention find industrial application in cellular communication.

ACRONYMS LIST

RACH random access channel

RRC radio resource control

SBFD subband non-overlapping full duplex

TECHNICAL EXAMPLES:

Example 1. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to:

- process, while in idle mode, information received from a network, the information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion; and o an extent of frequency multiplexing of the at least one RACH occasion;

- determine, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and

- initiate the random access procedure using at least one RACH occasion from among the set of RACH occasions. Example 2. An apparatus according to Example 1, further configured to receive, while in connected mode, an SBFD time and frequency domain configuration.

Example 3. The apparatus according to Example 1 or 2, wherein the information received from the network indicates which slots from the sequence of SBFD slots contain at least one RACH occasion by one of:

■ indicating an uplink or flexible slot, before which a predetermined number of slots contain RACH occasions;

■ indicating a reference slot and a last uplink or flexible slot, wherein slots between the reference slot and the last uplink or flexible slot contain RACH occasions; or

■ indicating a bitmap indicating the SBFD slots containing at least one RACH occasion.

Example 4. The apparatus according to any of Examples 1 - 3, wherein the information received from the network indicates the frequency start value of the at least one RACH occasion by:

■ indicating an initial frequency of an uplink sub-band in a carrier and a frequency offset from the initial frequency to a first RACH occasion, or by

■ indicating a frequency offset between RACH occasion in uplink slots and RACH occasions in SBFD slots.

Example 5. The apparatus according to any preceding Example, wherein the information received from the network is received in a broadcasted system information block while the apparatus is in the idle mode.

Example 6. The apparatus according to any of Examples 1 - 5, wherein the SBFD slots are on a time division duplex, TDD, carrier.

Example 7. The apparatus according to any of Examples 1 - 6, further configured to receive, when in the idle mode, a time domain allocation of the sequence of SBFD slots from the network. Example 8. The apparatus according to any of Examples 1 - 7, further configured to receive, when in the idle mode, a frequency domain allocation SBFD subbands for the sequence of SBFD slots from the network.

Example 9. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to:

- broadcast in a cell controlled by the apparatus information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion, and o an extent of frequency multiplexing of the at least one RACH occasion, and

- receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

Example 10. An apparatus according to Example 9, further configured to provide to a user equipment which is in connected mode, an SBFD time and frequency domain configuration.

Example 11. The apparatus according to Example 9 or 10, wherein the broadcasted information indicates which slots from the sequence of SBFD slots contain at least one RACH occasion by one of:

■ indicating a reference slot and a last uplink or flexible slot, wherein slots between the reference slot and the last uplink or flexible slot comprise RACH occasions; or

Example 12. The apparatus according to any of Examples 9 - 11, wherein the broadcasted information indicates the frequency start value of the at least one RACH occasion by: ■ indicating an initial frequency of an uplink sub-band in a carrier and a frequency offset from the initial frequency to a first RACH occasion, or by

Example 13. The apparatus according to any of Examples 9 - 12, wherein the apparatus is configured to broadcast the broadcasted information in a system information block.

Example 14. A method comprising:

- processing, by an apparatus and while in idle mode, information received from a network, the information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion; and o an extent of frequency multiplexing of the at least one RACH occasion;

- determining, based at least in part on the information received from the network, a set of RACH occasions for initiating a random access procedure, wherein the set of RACH occasions are in SBFD uplink subband, and

- initiating the random access procedure using at least one RACH occasion from among the set of RACH occasions.

Example 15. A method comprising:

- broadcasting, in a cell controlled by an apparatus performing the method, information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion; and o an extent of frequency multiplexing of the at least one RACH occasion, and

- receiving an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information. Example 16. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least:

- initiate the random access procedure using at least one RACH occasion from among the set of RACH occasions.

Example 17. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least:

- broadcast in a cell controlled by the apparatus information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion, and o an extent of frequency multiplexing of the at least one RACH occasion, and receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

Example 18. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to:

- process, while in idle mode, information received from a network, the information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion; and o an extent of frequency multiplexing of the at least one RACH occasion by one of:

■ indicating a number of multiplexed RACH occasions in SBFD slots, or

■ a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots, and

- initiate the random access procedure using at least one valid RACH occasion from among the set of RACH occasions.

Example 19. An apparatus according to Example 18, further configured to receive, while in connected mode, an SBFD time and frequency domain configuration.

Example 20. The apparatus according to Example 18 or 19, wherein the information received from the network indicates which slots from the sequence of SBFD slots contain at least one RACH occasion by one of:

Example 21. The apparatus according to any of Examples 18 - 20, wherein the information received from the network indicates the frequency start value of the at least one RACH occasion by:

■ indicating an initial frequency of an uplink sub-band in a carrier and a frequency offset from the initial frequency to a first RACH occasion, or by indicating a frequency offset between RACH occasion in uplink slots and RACH occasions in SBFD slots.

Example 22. The apparatus according to any of Examples 18 - 21, wherein the information received from the network is received in a broadcasted system information block while the apparatus is in idle mode.

Example 23. The apparatus according to any of Examples 18 - 22, wherein the SBFD slots are on a time division duplex, TDD, carrier.

Example 24. The apparatus according to any of Examples 18 - 23, further configured to receive, when in the idle mode, a time domain allocation of the sequence of SBFD slots from the network.

Example 25. The apparatus according to any of Examples 18 - 24, further configured to receive, when in the idle mode, a frequency domain allocation SBFD subbands for the sequence of SBFD slots from the network.

Example 26. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to:

- broadcast in a cell controlled by the apparatus information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion, and o an extent of frequency multiplexing of the at least one RACH occasion by one of:

■ indicating a number of multiplexed RACH occasions in SBFD slots, or

- receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information. Example 27. An apparatus according to Example 26, further configured to provide to a user equipment which is in connected mode, an SBFD time and frequency domain configuration.

Example 28. The apparatus according to Example 26 or 27, wherein the broadcasted information indicates which slots from the sequence of SBFD slots contain at least one RACH occasion by one of:

Example 29. The apparatus according to any of Examples 26 - 28, wherein the broadcasted information indicates the frequency start value of the at least one RACH occasion by:

Example 30. The apparatus according to any of Example 26 - 29, wherein the apparatus is configured to broadcast the broadcasted information in a system information block.

Example 3 E A method comprising:

- processing, by an apparatus and while in idle mode, information received from a network, the information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion; and o an extent of frequency multiplexing of the at least one RACH occasion by one of:

■ indicating a number of multiplexed RACH occasions in SBFD slots, or

■ a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots, and;

- initiating the random access procedure using at least one valid RACH occasion from among the set of RACH occasions.

Example 32. A method comprising:

- broadcasting, in a cell controlled by an apparatus performing the method, information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion; and o an extent of frequency multiplexing of the at least one RACH occasion by one of:

■ indicating a number of multiplexed RACH occasions in SBFD slots, or

- receiving an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

Example 33. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least:

- process, while in idle mode, information received from a network, the information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion; o an extent of frequency multiplexing of the at least one RACH occasion by one of:

■ indicating a number of multiplexed RACH occasions in SBFD slots, or

Example 34. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least:

- broadcast in a cell controlled by the apparatus information indicating: o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots contain at least one random access channel, RACH, occasion; o a frequency start value of the at least one RACH occasion; o an extent of frequency multiplexing of the at least one RACH occasion by one of:

■ indicating a number of multiplexed RACH occasions in SBFD slots, or

■ a bitmap indicating which RACH occasions of an uplink slot are also valid in SBDF slots, and receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information. Example 35. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to:

- process, while in idle mode, information received from a network, the information indicating: o frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and o which slots from a sequence of subband non-overlapping full duplex, SBFD slots of the TDD carrier contain at least one random access channel, RACH, occasion;

Example 36. An apparatus according to Example 35, further configured to receive, while in connected mode, an SBFD time and frequency domain configuration.

Example 37. The apparatus according to Example 35 or 36, wherein the information received from the network indicates which slots from the sequence of SBFD slots contain at least one RACH occasion by one of:

Example 38. The apparatus according to any of Examples 35 - 37, wherein the frequency domain allocation of the at least one set of RACH occasions in uplink slots is used for the set of RACH occasions in the SBFD uplink subband. Example 39. The apparatus according to any of Examples 35 - 37, wherein the information received from the network indicates a frequency start value of the at least one RACH occasion in the SBFD uplink subband and the apparatus is caused to perform: using an extent of frequency multiplexing of the at least one set of RACH occasions in uplink slots for the set of RACH occasions in the SBFD uplink subband.

Example 40. The apparatus according to any of Examples 35 - 37, wherein the information received from the network indicates an extent of frequency multiplexing of the at least one RACH occasion in the SBFD uplink subband; and the apparatus is caused to perform: using a frequency start value of the at least one set of RACH occasions in uplink slots for the set of RACH occasions in the SBFD uplink subband.

Example 41. The apparatus according to any of Examples 35 - 40, wherein the apparatus is configured to receive the information received from the network in a broadcasted system information block while the apparatus is in idle mode.

Example 42. The apparatus according to any of Examples 35 - 41, further configured to receive, when in the idle mode, a time domain allocation of the sequence of SBFD slots from the network.

Example 43. The apparatus according to any of Examples 35 - 42, further configured to receive, when in the idle mode, a frequency domain allocation SBFD subbands for the sequence of SBFD slots from the network.

Example 44. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to:

- broadcast in a cell controlled by the apparatus information indicating: o a frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion, and

Example 45. An apparatus according to Example 44, further configured to provide to a user equipment which is in connected mode, an SBFD time and frequency domain configuration.

Example 46. The apparatus according to Example 44 or 45, wherein the broadcasted information indicates which slots from the sequence of SBFD slots contain at least one RACH occasion by one of:

Example 47. The apparatus according to any of Examples 44 - 46, wherein the broadcasted information further indicates at least one of the following:

■ a frequency start value of the at least one RACH occasion in an SBFD uplink subband; or

■ an extent of frequency multiplexing of the at least one RACH occasion in the SBFD uplink subband.

Example 48. The apparatus according to any of Examples 44 - 47, wherein the apparatus is configured to broadcast the broadcasted information in a system information block.

Example 49. A method comprising:

- processing, by an apparatus and while in idle mode, information received from a network, the information indicating: o frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion;

Example 50. A method comprising:

- broadcasting, in a cell controlled by an apparatus performing the method, information indicating: o frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion, and

Example 51. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least:

- process, while in idle mode, information received from a network, the information indicating: o frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion;

Example 52. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least:

- broadcast in a cell controlled by the apparatus information indicating: o frequency domain resource allocation of at least one set of random access channel, RACH, occasions in uplink only slots of a time division duplex, TDD, carrier, and o which slots from a sequence of subband non-overlapping full duplex, SBFD, slots of the TDD carrier contain at least one random access channel, RACH, occasion, and receive an initial random access signal from a user equipment using at least one RACH occasion from among a set of RACH occasions indicated by the broadcasted information.

Claims

CLAIMS:

1. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to:

2. An apparatus according to claim 1, further configured to receive, while in connected mode, an SBFD time and frequency domain configuration.

3. The apparatus according to claim 1 or 2, wherein the information received from the network indicates which slots from the sequence of SBFD slots contain at least one RACH occasion by one of:

4. The apparatus according to any of claims 1 - 3, wherein the information received from the network indicates the frequency start value of the at least one RACH occasion by:

■ indicating an initial frequency of an uplink sub-band in a carrier and a frequency offset from the initial frequency to a first RACH occasion, or by ■ indicating a frequency offset between RACH occasion in uplink slots and RACH occasions in SBFD slots.

5. The apparatus according to any preceding claim, wherein the information received from the network is received in a broadcasted system information block while the apparatus is in the idle mode.

6. The apparatus according to any of claims 1 - 5, wherein the SBFD slots are on a time division duplex, TDD, carrier.

7. The apparatus according to any of claims 1 - 6, further configured to receive, when in the idle mode, a time domain allocation of the sequence of SBFD slots from the network.

8. The apparatus according to any of claims 1 - 7, further configured to receive, when in the idle mode, a frequency domain allocation SBFD subbands for the sequence of SBFD slots from the network.

9. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to:

10. An apparatus according to claim 9, further configured to provide to a user equipment which is in connected mode, an SBFD time and frequency domain configuration.

11. The apparatus according to claim 9 or 10, wherein the broadcasted information indicates which slots from the sequence of SBFD slots contain at least one RACH occasion by one of: ■ indicating an uplink or flexible slot, before which a predetermined number of slots contain RACH occasions;

12. The apparatus according to any of claims 9 - 11, wherein the broadcasted information indicates the frequency start value of the at least one RACH occasion by:

13. The apparatus according to any of claims 9 - 12, wherein the apparatus is configured to broadcast the broadcasted information in a system information block.

14. A method comprising:

15. A method comprising:

16. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least:

17. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least: