Additional physical random access channel resource validation for network energy savings-capable user equipment

Abstract

A method performed by NES-capable user equipment (UE) is provided. The method includes selecting a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occ

Description

TECHNOLOGICAL FIELD

[0001] The present disclosure relates generally to telecommunications and, in particular, to physical random access channel adaptation for network energy savings. BACKGROUND

[0002] A telecommunications system can be seen as a facility that enables communication sessions between two or more entities such as user terminals, base stations and / or other nodes by providing carriers between the various entities involved in the communications path. A telecommunications system can be provided for example by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, video, electronic mail (email), text message, multimedia and / or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

[0003] In a wireless telecommunications system at least a part of a communication session between at least two stations occurs over a wireless link. Examples of wireless systems comprise public land mobile networks (PLMN), satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). Some wireless systems can be divided into cells, and are therefore often referred to as cellular systems.

[0004] A user can access the telecommunications system by means of an appropriate communication device or terminal. A communication device of a user may be referred to as user equipment (UE) or user device. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other users. The communication device may access a carrier provided by a station, for example a base station of a cell, and transmit and / or receive communications on the carrier.

[0005] The telecommunications system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and / or parameters which shall be used for the connection are also typically defined. One example of a telecommunications system is the Universal Mobile Telecommunications System (UMTS). Other examples of telecommunications systems are Long-Term Evolution (LTE), LTE Advanced and the so-called 5G or New Radio (NR) networks. NR is being standardized by the 3rd Generation Partnership Project (3GPP). BRIEF SUMMARY

[0006] Example implementations of the present disclosure are directed to telecommunications and, in particular, to physical random access channel adaptation for network energy savings. The present disclosure includes, without limitation, the following example implementations.

[0007] Some example implementations provide an apparatus implemented by a user equipment (UE) of a first type, the apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: select a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type; perform a validation of one or more of the second PRACH occasions, the validation of each second PRACH occasion of the one or more of the second PRACH occasions performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain; and transmit a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions.

[0008] Some example implementations provide an apparatus implemented by a user equipment (UE) of a first type, the apparatus comprising: means for selecting a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type; means for performing a validation of one or more of the second PRACH occasions, the validation of each second PRACH occasion of the one or more of the second PRACH occasions performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain; and means for transmitting a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions.

[0009] Some example implementations provide a method performed by a user equipment (UE) of a first type, the method comprising: selecting a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type; performing a validation of one or more of the second PRACH occasions, the validation of each second PRACH occasion of the one or more of the second PRACH occasions performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain; and transmitting a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions.

[0010] Some example implementations provide a computer-readable storage medium implemented at a user equipment (UE) of a first type, the computer-readable storage medium being non-transitory and having instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: select a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type; perform a validation of one or more of the second PRACH occasions, the validation of each second PRACH occasion of the one or more of the second PRACH occasions performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain; and transmit a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions.

[0011] These and other features, aspects, and advantages of the present disclosure will be apparent from a reading of the following detailed description together with the accompanying figures, which are briefly described below. The present disclosure includes any combination of two, three, four or more features or elements set forth in this disclosure, regardless of whether such features or elements are expressly combined or otherwise recited in a specific example implementation described herein. This disclosure is intended to be read holistically such that any separable features or elements of the disclosure, in any of its aspects and example implementations, should be viewed as combinable unless the context of the disclosure clearly dictates otherwise.

[0012] It will therefore be appreciated that this Brief Summary is provided merely for purposes of summarizing some example implementations so as to provide a basic understanding of some aspects of the disclosure. Accordingly, it will be appreciated that the above described example implementations are merely examples and should not be construed to narrow the scope or spirit of the disclosure in any way. Other example implementations, aspects and advantages will become apparent from the following detailed description taken in conjunction with the accompanying figures which illustrate, by way of example, the principles of some described example implementations. BRIEF DESCRIPTION OF THE FIGURE(S)

[0013] Having thus described example implementations of the disclosure in general terms, reference will now be made to the accompanying figures, which are not necessarily drawn to scale, and wherein:

[0014] FIG. 1 illustrates a telecommunications system that includes one or more public land mobile networks (PLMNs) coupled to one or more external data networks, according to some example implementations of the present disclosure;

[0015] FIG. 2 illustrates a deployment of a PLMN, according to some example implementations;

[0016] FIG. 3 illustrates physical random access channel (PRACH) resources that may be configured for various PRACH configuration indices;

[0017] FIG. 4 illustrates a scenario in which a radio access node is configured to provide four beams per cell;

[0018] FIG. 5 illustrates PRACH resources that may be configured for a PRACH configuration index, and including a mapping between synchronization signal blocks and random access channel (RACH) occasions for the scenario shown in FIG. 4;

[0019] FIG. 6 illustrates the PRACH resources of FIG. 6 as legacy PRACH resources, and includes additional PRACH resources configured for the user equipments (UEs) capable of network energy savings;

[0020] FIGS. 7A, 7B and 7C illustrate respectively a partial overlap, functional overlap and full overlap between an additional PRACH occasion and an adjacent legacy PRACH occasion, according to some example implementations;

[0021] FIGS. 8A, 8B, 8C, 8D, 8E and 8F are flowcharts illustrating various steps in a method performed by a UE of a first type, according to various example implementations;

[0022] FIG. 9 is a flowchart illustrating various steps in a method performed by a UE of the first type, according to some example implementations; and

[0023] FIG. 10 illustrates an apparatus according to some example implementations. DETAILED DESCRIPTION

[0024] Some implementations of the present disclosure will now be described more fully hereinafter with reference to the accompanying figures, in which some, but not all implementations of the disclosure are shown. Indeed, various implementations of the disclosure may be embodied in many different forms and should not be construed as limited to the implementations set forth herein; rather, these example implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout.

[0025] Unless specified otherwise or clear from context, references to first, second or the like should not be construed to imply a particular order. A feature described as being above another feature (unless specified otherwise or clear from context) may instead be below, and vice versa; and similarly, features described as being to the left of another feature else may instead be to the right, and vice versa. Also, while reference may be made herein to quantitative measures, values, geometric relationships or the like, unless otherwise stated, any one or more if not all of these may be absolute or approximate to account for acceptable variations that may occur, such as those due to engineering tolerances or the like.

[0026] As used herein, unless specified otherwise or clear from context, the "or" of a set of operands is the "inclusive or" and thereby true if and only if one or more of the operands is true, as opposed to the "exclusive or" which is false when all of the operands are true. Thus, for example, "[A] or [B]" is true if [A] is true, or if [B] is true, or if both [A] and [B] are true. Further, the articles "a" and "an" mean "one or more," unless specified otherwise or clear from context to be directed to a singular form. Furthermore, it should be understood that unless otherwise specified, the terms "data," "content," "digital content," "information," and similar terms may be at times used interchangeably. The term "network" may refer to a group of interconnected computers including clients and servers; and within a network, these computers may be interconnected directly or indirectly by various means including via one or more switches, routers, gateways, access points or the like.

[0027] Reference may be made herein to terms specific to a particular system, architecture or the like, but it should be understood that example implementations of the present disclosure may be equally applicable to any of a number of systems, architectures and the like. For example, reference may be made to 3GPP technologies such as Global System for Mobile Communications (GSM), UMTS, LTE, LTE Advanced, 5G NR, 5G Advanced and 6G; however, it should be understood that example implementations of the present disclosure may be equally applicable to non-3GPP technologies such as IEEE 802, Bluetooth and Bluetooth Low Energy.

[0028] Further, as used in this application, the term "circuitry" may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry); (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions); or (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.

[0029] The above 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.

[0030] FIG. 1 illustrates a telecommunications system 100 according to various example implementations of the present disclosure. The telecommunications system generally includes one or more telecommunications networks. As shown, for example, the system includes one or more public land mobile networks (PLMNs) 102 coupled to one or more other external data networks 104 - notably including a wide area network (WAN) such as the Internet. Each of the PLMNs includes a core network (CN) 106 backbone such as the Evolved Packet Core (EPC) of LTE, the 5G core network (5GC) or the like; and each of the core networks and the Internet are coupled to one or more radio access networks (RANs) 108, air interfaces or the like that implement one or more radio access technologies (RATs). As used herein, a "network device" refers to any suitable device at a network side of a telecommunications network. Examples of suitable network devices are described in greater detail below.

[0031] In addition, the system includes one or more radio units that may be varyingly known as user equipment (UE) 110, terminal device, terminal equipment, mobile station or the like. The UE is generally a device configured to communicate with a network device or a further UE in a telecommunications network. The UE may be a portable computer (e.g., laptop, notebook, tablet computer), mobile phone (e.g., cell phone, smartphone), wearable computer (e.g., smartwatch), or the like. In other examples, the UE may be an Internet of things (loT) device, an industrial loT (IIoT device), a vehicle equipped with a vehicle-to-everything (V2X) communication technology, or the like. In some examples, as referenced by 3GPP, the UE may be a narrowband loT (NB-IoT) device, an enhanced machine-type communication (eMTC) device, a reduced capability (RedCap) device, an ambient loT device, or the like.

[0032] In operation, these UEs 110 may be configured to connect to one or more of the RANs 108 according to their particular radio access technologies to thereby access a particular CN 106 of a PLMN 102, or to access one or more of the external data networks 104 (e.g., the Internet). The external data network may be configured to provide Internet access, operator services, 3rd party services, etc. For example, the International Telecommunication Union (ITU) has classified 5G mobile network services into three categories: enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine type communications (mMTC) or massive internet of things (MIoT).

[0033] Examples of radio access technologies include 3GPP radio access technologies such as GSM, UMTS, LTE, LTE Advanced, 5G NR, 5G Advanced, and 6G. Other examples of radio access technologies include IEEE 802 technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.15 (including 802.15.1 (WPAN / Bluetooth), 802.15.4 (Zigbee) and 802.15.6 (WBAN)), Bluetooth, Bluetooth Low Energy (BLE), ultra wideband (UWB), and the like. Generally, a radio access technology may refer to any 2G, 3G, 4G, 5G, 6G or higher generation mobile communication technology and their different versions, as well as to any other wireless radio access technology that may be arranged to interwork with such a mobile communication technology to provide access to the CN 106 of a mobile network operator (MNO).

[0034] In various examples, a RAN 108 may be configured as one or more macrocells, microcells, picocells, femtocells or the like. The RAN may generally include one or more radio access nodes that are configured to interact with UEs 110. In various examples, a radio access node may be referred to as a base station (BS), access point (AP), base transceiver station (BTS), Node B (NB), evolved NB (eNB), macro BS, NB (MNB) or eNB (MeNB), home BS, NB (HNB) or eNB (HeNB), next generation NB (gNB), enhanced gNB (en-gNB), next generation eNB (ng-eNB), or the like. The RAN may include some type of network controlling / governing entity responsible for control of the radio access nodes. The network controlling / governing entity and radio access node may be separate or integrated into a single apparatus. The network controlling / governing entity may include processing circuity configured to carry out various management functions, etc. The processing circuity may be associated with a memory, computer-readable storage medium or database for maintaining information required in the management functions.

[0035] A RAN 108 may be centralized or distributed. In various examples, components of a RAN may be interconnected by Ethernet, Gigabit Ethernet, Asynchronous Transfer Mode (ATM), optical fiber, dark fiber, passive wavelength division multiplexing (WDM), WDM passive optical network (WDM-PON), optical transport network (OTN), time sensitive networking (TSN) and / or any other data link layer network, possibly including radio links. The RAN may be connected to a CN 106 through one or more gateways, network functions or the like.

[0036] As will be appreciated, a PLMN 102 may be deployed in a number of different manners. FIG. 2 illustrates a deployment 200 of a PLMN, such as a 4G LTE, 5G or 6G deployment, according to some example implementations. As shown, the deployment includes a CN 106, and RAN 108 with one or more radio access nodes 202 configured to interact with UEs 110. In a 4G LTE deployment, the EPC is the CN, and the evolved UMTS terrestrial radio access network (E-UTRAN) is the RAN; and the E-UTRAN includes one or more eNBs (radio access nodes) configured to connect UEs to the E- UTRAN to thereby access the EPC. Similarly, in a 5G deployment, the 5GC is the CN 106, and the next generation (NG) radio access network (NG-RAN) is the RAN 108; and the NG-RAN includes one or more gNBs (radio access nodes) configured to connect UEs 110 to the NG-RAN to thereby access the 5GC (at times referred to as the NGC). The term 'gNB' in 5G may correspond to the eNB in 4G LTE.

[0037] Some deployments of 4G LTE and 5G in particular are considered standalone (SA) deployments. Other deployments combine 4G LTE and 5G technologies, and are referred to as non-standalone (NSA) deployments. In some deployments, the E-UTRAN includes one or more ng-eNBs that are configured to communicate with the 5GC, and that may also be configured to communicate with one or more gNBs. Similarly, in another deployment, the NG-RAN may include one or more en-gNBs that are configured to communicate with the EPC, and that may also be configured to communicate with one or more eNBs. In various instances, a single UE 110, a dual-mode or multimode UE, may support multiple (two or more) RANs—thereby being configured to connect to multiple RANs, such as 4G LTE and 5G.

[0038] In some deployments, such as deployment 200, operations of the radio access node 202 may be carried out, at least partly, in a central / centralized unit (CU), such as a server, host or node, operationally coupled to a distributed unit (DU), such as a radio head / node. It is also possible that node operations may be distributed among a plurality of servers, hosts or nodes.

[0039] It should also be understood that the distribution of work between CN 106 operations and radio access node 202 operations may vary depending on implementation. Thus, a 5G network architecture may be based on a so-called CU-DU split. One gNB-CU (central node) may control one or more gNB-DUs. The gNB-CU may control a plurality of spatially separated gNB-DUs, acting at least as transmit / receive (Tx / Rx) nodes. In some example implementations, however, the gNB-DUs (also called DU) may include, for example, a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the gNB-CU (also called a CU) may include the layers above the RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC), and an internet protocol (IP) layer. Other functional splits are also possible. It is considered that a skilled person is familiar with the open systems interconnection (OSI) model and the functionalities within each layer.

[0040] In some example implementations, the server or CU may generate a virtual network through which the server communicates with the radio node. In general, virtual networking may involve a process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Such virtual network may provide flexible distribution of operations between the server and the radio head / node. In practice, any digital signal processing task may be performed in either the CU or the DU, and the boundary where the responsibility is shifted between the CU and the DU may be selected according to implementation.

[0041] An area of focus in networks, such as 5G networks, is network energy savings (NES), such as at the RAN 108 which consumes a significant amount of the total energy consumption in the PLMN. Current efforts aim to identify adaptation techniques of transmissions and / or receptions in time, frequency, spatial, and power domains, with potential support / feedback from the UE 110, potential UE assistance information, and information exchange / coordination over network interfaces. A more recent work item on NES relates to adaptation of common signal / channel transmissions, such as physical random access channel (PRACH) transmissions in the time domain (e.g., adapting periodicity). The radio access node 202 in the RAN configures PRACH resources that define PRACH occasions for the UEs to transmit PRACH preambles.

[0042] In the frequency domain, PRACH resources are determined by the RRC parameter msgl-FDMand msg 1-FrequencyStart. In this regard, msgl-FDMspecifies how many RO are allocated in the frequency domain (in one time instance in the time domain). The other parameter, msg 1-FrequencyStart, indicates an offset of the lowest RO in the frequency domain with respect to a first physical resource block.

[0043] In the time domain, PRACH resources are obtained from tables of random access configurations organized by a PRACH configuration index (prach-Configurationlndex). The random access configurations provide, for example, PRACH periodicity, sub-frame number, number of PRACH slots within a subframe, and number of time-domain PRACH occasions. The PRACH periodicity may be configured from 10 ms up to 160 ms, given by x: {1, 2, 4, 8, 16}. The sub-frame number indicates sub-frame number(s) containing PRACH slots. And the number of PRACH slots within a subframe may be given as none, one or two. FIG. 3 illustrates PRACH resources that may be configured for PRACH configuration indices 5, 17 and 0.

[0044] Also in 3GPP, synchronization signal (SS) / physical broadcast channel (PBCH) blocks, (i.e., synchronization signal blocks (SSBs)), are associated with different beams, and a UE 110 selects a certain beam and sends a PRACH preamble using that beam. For the RAN 108 to determine which beam the UE has selected, 3GPP defines a specific mapping between SSB and random access channel (RACH) occasion (RO) (also at times referred to as a PRACH occasion). The mapping between SSB and RO is defined by the RRC parameters msgl-FDMand ssb-perRACH-OccasionAndCB-PreamblesPerSSB. Again, msgl-FDMspecifies how many RO are allocated in the frequency domain (at the same location in time domain). The other parameter, ssb-perRACH-OccasionAndCB-PreamblesPerSSB, specifies how many SSBs can be mapped to one RO {ssb-perRACH-Occasion) and how many preamble indices can be mapped to single SSB (CB-PreamblesPerSSB). If the number of SSBs that can be mapped to one RO is represented by k, and k< 1, one SS / PBCH block index (i.e., SSB index) is mapped to 1 / kconsecutive valid PRACH occasions.

[0045] FIG. 4 illustrates a scenario in which a radio access node 202 is configured to provide four beams 402A, 402B, 402C and 402D that are associated with respective SSBs per cell (the beams at times in the appropriate context referred to as SSB beams). Assuming the above RRC parameters are set as follows: msgl-FDM = 1, and ssb-perRACH-OccasionAndCB-PreamblesPerSSB = 1. FIG. 5 illustrates the PRACH resources that may be configured with prach-Configurationlndex = 5, and includes a SSB-RO mapping for the scenario shown in FIG. 4.

[0046] It has been agreed that for adaptation of PRACH in the time domain, additional PRACH resources may be configured for NES-capable UEs. In some examples, the NES capability of the NES-capable UEs may be as provided in 5G Advanced in Release 19 (Rel-19); and accordingly, the NES-capable UEs may at times be referred to as Rel-19 UEs. In particular, adaptation of PRACH may include the configuration of legacy PRACH resources for legacy UEs and NES-capable UEs, and the configuration of additional PRACH resources for NES-capable UEs. These additional PRACH resources may be dedicated to the NES-capable UEs.

[0047] By the aforementioned agreement, NES-capable UEs may be configured with additional PRACH resources that may overlap in time and / or frequency with legacy PRACH resources configured for the NES-capable UEs and legacy UEs. Assume, for example, that FIG. 5 illustrates legacy PRACH resources configured for NES-capable UEs and legacy UEs. FIG. 6 illustrates one example including those legacy PRACH resources, as well as additional PRACH resources configured for the NES-capable UEs. The additional PRACH resources are configured with prach-Configurationindex = 17, and shown in different cross hatching than the legacy PRACH resources. As also shown, the additional PRACH resources overlap with the legacy PRACH resources at subframe 4 of frames 0 and 2. In this regard, subframe number 4 of frames 0 and 2 may be used by both legacy and NES-capable UEs for initiating random access.

[0048] It has also been agreed that SSB-RO mapping for the additional PRACH resources is separate from the SSB-RO mapping of the legacy PRACH resources. In other words, legacy and additional PRACH resources may follow an independent mapping to SSBs and may be independently handled by both the RAN 108 and the UE 110. It is currently unclear, however, whether / how to handle the SSB-RO mapping for the additional PRACH resources overlap in both time and frequency with the legacy PRACH resources.

[0049] Some radio access nodes 202 may be implemented using a fully digital architecture with digital beamforming may create as many digital receive beams as practically needed. These radio access nodes may have more than one SSB beam mapped to one RO, and / or multiple ROs multiplexed in frequency domain, each of the ROs with different SSB beams. Other radio access nodes may be implemented without a fully digital architecture, and include analog or hybrid beamforming. These other radio access nodes may be restricted terms of how many SSB beams the radio access node can use at the same time. Additionally, radio access nodes with analog beamforming may be incapable of being frequency selective, and thereby unable to create different SSB beams over different ROs if the ROs are multiplexed in the frequency domain during the same time instance.

[0050] For specific implementations in which a radio access nodes 202 may be unable to create more than one SSB beam per time and frequency instance, it may be suggested to use different random access preambles between the PRACH resources and the additional PRACH resources. This approach, however, further increases preamble partitioning and collision probability on the PRACH beyond what may be desirable.

[0051] In view of the foregoing, example implementations of the present disclosure therefore provide a solution for NES-capable UEs (configured with additional PRACH resources) to facilitate the PRACH adaptation holding even when the radio access node is only able to create one SSB per time instance. According to some example implementations, a NES-capable UE may assess whether a given additional RO is valid for transmission of a random access preamble, when the additional RO overlaps in time or frequency with a legacy RO.

[0052] This assessment may be based on a number of criteria that depend on interactions between the additional PRACH resources and the legacy PRACH resources. In some examples, the criteria may include whether an additional RO and a legacy RO partially overlap, functionally overlap, or fully overlap, in the time and frequency domains. Any one or more of the criteria may be specified, and thus inherent to operations performed by an NES-capable UE 110, or configured per cell via suitable indicator (e.g., a flag).

[0053] According to example implementations of the present disclosure, a NES-capable UE may transmit a random access preamble at a legacy RO, or at an additional RO but only when the additional RO is considered valid based on its proximity to an adjacent legacy RO in the time and frequency domains. As described below, some example implementations may depend on the architecture of the radio access node 202, which may target maximization of the number of valid additional PRACH resources to ensure optimal performance. These example implementations may preserve the inherent larger flexibility of a fully digital architecture, while ensuring that any non-fully digital architecture may also be used without error or constraint. Other example implementations are architecture independent.

[0054] Some example implementations of the present disclosure therefore provide a UE 110 of a first type (e.g., NES-capable UE). The UE may select a SSB that is mapped to first PRACH occasions (e.g., legacy PRACH occasions) configured for UEs of the first type and UEs of a second type (e.g., legacy UEs). The SSB is also mapped to second PRACH occasions (e.g., additional PRACH occasions) configured for UEs of the first type.

[0055] As explained below, the UE 110 may perform a validation of one or more of the second PRACH occasions. In this regard, the UE may perform the validation of each second PRACH occasion based on proximity (of the second PRACH occasion) to an adjacent one of the first PRACH occasions in the time domain and the frequency domain. The UE may then transmit a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions. The UE may otherwise make a determination to not transmit a random access preamble at an earliest one of the second PRACH occasions, based on proximity of the earliest one of the second PRACH occasions to the adjacent one of the first PRACH occasions in the time domain and the frequency domain,

[0056] As described above, the SSB may be one of a plurality of SSBs associated with a plurality of beams of a cell provided by a radio access node 202. In some examples, for the validation of a second PRACH occasion, the UE 110 may determine the second PRACH occasion overlaps an adjacent one of the first PRACH occasions in the time domain but not in the frequency domain, which may indicate a partial overlap. This is shown in FIG. 7A for an additional RO and adjacent legacy RO. The UE may then infer or otherwise determine whether the cell has a capability to create multiple ones of the plurality of beams in each time instance in the time domain, and in one or more frequency instances in the frequency domain. If so, the second PRACH occasion is valid. The second PRACH occasion is otherwise invalid, and in some examples may be dropped from consideration by the UE.

[0057] In some examples, the capability of the cell provided by the radio access node 202 may be inferred or otherwise determined based on parameters of a configuration of PRACH resources that define the first PRACH occasions. The parameters of the configuration may include a first parameter (e.g., ssb-perRACH-Occasion) that indicates a number of the plurality of SSBs mapped to each PRACH occasion, and a second parameter that includes a number of PRACH occasions allocated in the frequency domain in one time instance in the time domain (e.g., msgl-FDM).

[0058] In some more particular example, the UE 110 may determine the second PRACH occasion is valid when a product of the parameters is greater than one. The UE may make a determination to not transmit the random access preamble on the second PRACH occasion (as the earliest PRACH occasion of the first and second PRACH occasions) when the product of the number of SSBs mapped per PRACH occasion (represented as k above) and value of the msgl-FDMis lower than or equal to one (i.e., k x msgl-fdm <= 1). Stated positively, the UE may make the determination to transmit the random access preamble on the second PRACH occasion (as the earliest PRACH occasion of the first and second PRACH occasions) when the product of the number of SSBs mapped per PRACH occasion and value of the msgl-FDMis greater than one (i.e., k x msgl-fdm >1).

[0059] In some examples, for the validation of the second PRACH occasion, the UE 110 may determine the second PRACH occasion does not overlap the adjacent one of the first PRACH occasions in either the time domain or the frequency domain. The UE may then determine whether the second PRACH occasion is separated from the adjacent one of the PRACH occasions by at least specified number of symbols (N_sym) in the time domain; and if so, the second PRACH occasion is valid. When the separation is less than the specified number of symbols, the second PRACH occasion and the adjacent first PRACH occasion may be considered functionally overlapped, as shown in FIG. 7B for an additional RO and adjacent legacy RO.

[0060] The UE 110 may make a determination to not transmit the random access preamble on the second PRACH occasion (as the earliest PRACH occasion of the first and second PRACH occasions) when the second PRACH occasion is separated from the adjacent one of the PRACH occasions by less than the specified number of symbols (N_syni) in the time domain. Stated positively, the UE may make the determination to transmit the random access preamble on the second PRACH occasion (as the earliest PRACH occasion of the first and second PRACH occasions) when the second PRACH occasion is separated from the adjacent one of the PRACH occasions by at least the specified number of symbols (N_sym) in the time domain.

[0061] The separation beetween the second PRACH occasion and the adjacent first PRACH occasion may be determined in a number of different manners. In some examples, the separation may be determined as the number of symbols between the first or last symbol of the second PRACH occasion and respectively the last or first symbol of the adjacent first PRACH occasion. In various examples, the specified number of symbols (N_sym) may be hard-coded in an appropriate specification, signaled via higher-layer signaling (e.g., system information block type 1 - SIB1), or dynamically signaled (e.g., via downlink control information - DCI).

[0062] In some examples, for the validation of the second PRACH occasion, the UE 110 may whether the second PRACH occasion fully overlaps an adjacent one of the first PRACH occasions in both the time domain and the frequency domain; and if so, the second PRACH occasion is invalid. FIG. 7C illustrates a full overlap between an additional RO and adjacent legacy RO.

[0063] The UE 110 may make a determination to not transmit the random access preamble on the second PRACH occasion (as the earliest PRACH occasion of the first and second PRACH occasions) when the second PRACH occasion fully overlaps an adjacent one of the first PRACH occasions in both the time domain and the frequency domain.

[0064] According to some examples, the UE 110 may perform the validation of a number of the second PRACH occasions, including at least an earliest one and a next earliest one of the second PRACH occasions. The UE may identify an earliest one of the number of the second PRACH occasions that is an earliest valid one of the number of the second PRACH occasions. The UE may then transmit the random access preamble at the earliest PRACH occasion among the first PRACH occasions and the earliest valid one of the number of the second PRACH occasions.

[0065] In other examples, the UE 110 may identify that an earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions is an earliest one of the second PRACH occasions. The UE may then perform the validation of the earliest one of the second PRACH occasions. When the earliest one of the second PRACH occasions is invalid, the UE may identify a next earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions. When the next earliest PRACH occasion is a first PRACH occasion of the first PRACH occasion, the UE may transmit the random access preamble at the first PRACH occasion. But when the next earliest PRACH occasion is a next earliest one of the second PRACH occasions, the UE may perform the validation of the next earliest one of the second PRACH occasions (and transmit on the next earliest one fo the second PRACH occasions when valid).

[0066] FIGS. 8A - 8F are flowcharts illustrating various steps in a method 800 performed by a user equipment (UE) of a first type, according to various example implementations. The method includes selecting a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type, as shown at block 802 of FIG. 8A. The method includes performing a validation of one or more of the second PRACH occasions, where the validation of each second PRACH occasion of the one or more of the second PRACH occasions is performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain, as shown at block 804. And the method includes transmitting a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions, as shown at block 806.

[0067] In some examples, the SSB is one of a plurality of SSBs associated with a plurality of beams of a cell. In some of these examples, performing the validation at block 804 includes determining a second PRACH occasion of the one or more second PRACH occasions overlaps an adjacent one of the first PRACH occasions in the time domain but not in the frequency domain, as shown at at block 808 of FIG. 8B. Also in some of these examples, performing the validation includes determining a capability of the cell to create multiple ones of the plurality of beams in each time instance in the time domain, and in one or more frequency instances in the frequency domain, and that the second PRACH occasion is thereby valid, as shown at block 810.

[0068] In some examples, the capability of the cell is determined at block 810 based on parameters of a configuration of PRACH resources that define the first PRACH occasions. In some of these examples. The parameters of the configuration include a first parameter that indicates a number of the plurality of SSBs mapped to each PRACH occasion, and a second parameter that includes a number of PRACH occasions allocated in the frequency domain in one time instance in the time domain. And in some further examples, determining the capability of the cell comprises determining that a product of the parameters is greater than one.

[0069] In some examples, performing the validation at block 804 includes determining a second PRACH occasion of the one or more second PRACH occasions does not overlap an adjacent one of the first PRACH occasions in either the time domain or the frequency domain, as shown at block 812 of FIG. 8C. Also in some of these examples, performing the validation includes determining the second PRACH occasion is separated from the adjacent one of the PRACH occasions by at least specified number of symbols in the time domain, and that the second PRACH occasion is thereby valid, as shown at block 814.

[0070] In some examples, performing the validation at block 804 includes determining a second PRACH occasion of the one or more second PRACH occasions fully overlaps an adjacent one of the first PRACH occasions in both the time domain and the frequency domain, and that the second PRACH occasion is thereby invalid, as shown at block 816 of FIG. 8D.

[0071] In some examples, performing the validation at block 804 includes performing the validation of a number of the second PRACH occasions, including at least an earliest one and a next earliest one of the second PRACH occasions, as shown at block 818 of FIG. 8E. In some of these examples, performing the validation also includes identifying an earliest one of the number of the second PRACH occasions that is an earliest valid one of the number of the second PRACH occasions, as shown at block 820. The random access preamble may then be transmitted at block 806 at the earliest PRACH occasion among the first PRACH occasions and the earliest valid one of the number of the second PRACH occasions.

[0072] In some examples, performing the validation at block 804 includes identifying that an earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions is an earliest one of the second PRACH occasions, as shown at block 822 of FIG. 8F. In some of these examples, performing the validation also includes performing the validation of the earliest one of the second PRACH occasions, as shown at block 824. When the earliest one of the second PRACH occasions is invalid, a next earliest PRACH occasion may be identified among the first PRACH occasions and the second PRACH occasions, as shown at block 826. And when the next earliest PRACH occasion is a next earliest one of the second PRACH occasions, the validation of the next earliest one of the second PRACH occasions may be performed, as shown at block 828.

[0073] FIG. 9 is a flowchart illustrating various steps in a method 900 performed by a user equipment (UE) of a first type, according to some example implementations. The method includes selecting a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type, as shown at block 902. And based on proximity of an earliest one of the second PRACH occasions to an adjacent one of the first PRACH occasions in a time domain and a frequency domain, the method includes making a determination to not transmit a random access preamble at the earliest one of the second PRACH occasions, as shown at block 904.

[0074] According to example implementations of the present disclosure, a telecommunications system 100 or PLMN 102, and its components such as a UE 110, CN 106, RAN 108 and / or radio access node 202, may be implemented by various means. Means for implementing the system and its components may include hardware, firmware, software, or combinations thereof. In some examples, one or more apparatuses may be configured to function as or otherwise implement the system and its components shown and described herein. In examples involving more than one apparatus, the respective apparatuses may be connected to or otherwise in communication with one another in a number of different manners, such as directly or indirectly via a wired or wireless network or the like.

[0075] According to some example implementations, at least some of the method 800 described with respect to FIGS. 8A - 8F may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. Similarly, at least some of the method 900 described with respect to FIG. 9 may be carried out by an apparatus comprising means for performing functions corresponding steps of the method Examples of a suitable apparatus may include a user equipment, user device, user terminal or the like. Other examples of a suitable apparatus may include a gNB (e.g., gNB-DU, gNB-CU), ng-eNB or any suitable apparatus, such as a server, host or node.

[0076] FIG. 10 illustrates an apparatus 1000 in which means for performing various functions includes hardware, alone or under direction of one or more computer programs from a computer-readable storage medium or other memory, such as computer memory, according to some example implementations of the present disclosure. Generally, an apparatus of example implementations of the present disclosure may comprise, include or be embodied in one or more fixed or portable electronic devices. Examples of suitable electronic devices include a wearable computer, mobile phone, portable computer, desktop computer, workstation computer, server (server computer) or the like. The apparatus may include one or more of each of a number of components such as, for example, processing circuitry 1002 connected to computer-readable storage medium or other memory 1004.

[0077] The processing circuitry 1002 may be composed of one or more processors alone or in combination with one or more computer-readable storage media. The processing circuitry is generally any piece of computer hardware that is capable of processing information such as, for example, data, computer programs and / or other suitable electronic information. The processing circuitry is composed of a collection of electronic circuits some of which may be packaged as an integrated circuit or multiple interconnected integrated circuits (an integrated circuit at times more commonly referred to as a "chip"). The processing circuitry may be configured to execute computer programs, which may be stored onboard the processing circuitry or otherwise stored in the memory 1004 (of the same or another apparatus).

[0078] The processing circuitry 1002 may be a number of processors, a multi-core processor or some other type of processor, depending on the particular implementation. Further, the processing circuitry may be implemented using a number of heterogeneous processor systems in which a main processor is present with one or more secondary processors on a single chip. As another illustrative example, the processing circuitry may be a symmetric multi-processor system containing multiple processors of the same type. In yet another example, the processing circuitry may be embodied as or otherwise include one or more ASICs, FPGAs or the like. Thus, although the processing circuitry may be capable of executing a computer program to perform one or more functions, the processing circuitry of various examples may be capable of performing one or more functions without the aid of a computer program. In either instance, the processing circuitry may be appropriately programmed to perform functions or operations according to example implementations of the present disclosure.

[0079] The memory 1004 is generally any piece of computer hardware that is capable of storing information such as, for example, data, computer programs, instructions 1006 (e.g., computer-readable program code) and / or other suitable information either on a temporary basis and / or a permanent basis. The memory may include volatile and / or non-volatile memory, and may be fixed or removable. Examples of suitable memory include recording media, random access memory (RAM), read-only memory (ROM), a hard drive, a flash memory, a thumb drive, a removable computer diskette, an optical disk or some combination thereof.

[0080] The memory 1004 is a non-transitory device capable of storing information. One example of a suitable memory is a computer-readable storage medium, which is distinguishable from a computer-readable transmission medium capable of carrying information from one location to another. Examples of suitable computer-readable transmission media comprise electronic carrier signals, telecommunications signals, or some combination thereof. As used herein, the term "non-transitory" is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM versus ROM). A computer-readable medium as described herein generally refers to a computer-readable storage medium or computer-readable transmission medium. A computer-readable medium is any entity or device capable in which information, such as one or more computer programs or portions thereof, may be stored and carried.

[0081] In addition to the memory 1004 (e.g., computer-readable storage medium), the processing circuitry 1002 may also be connected to one or more interfaces for displaying, transmitting and / or receiving information. The interfaces may include a communications interface 1008 and / or one or more user interfaces. The communications interface may be configured to transmit and / or receive information, such as to and / or from other apparatus(es), network(s) or the like. The communications interface may be configured to transmit and / or receive information by physical (wired) and / or wireless communications links. Examples of suitable communication interfaces include a network interface controller (NIC), wireless NIC (WNIC) or the like.

[0082] The user interfaces may include a display 1010 and / or one or more user input interfaces 1012. The display may be configured to present or otherwise display information to a user, suitable examples of which include a liquid crystal display (LCD), light-emitting diode (LED) display, organic LED (OLED) display, active-matrix OLED (AMOLED) or the like. The user input interfaces may be wired or wireless, and may be configured to receive information from a user into the apparatus, such as for processing, storage and / or display. Suitable examples of user input interfaces include a microphone, image or video capture device, keyboard or keypad, joystick, touchsensitive surface (separate from or integrated into a touchscreen), biometric sensor or the like. The user interfaces may further include one or more interfaces for communicating with peripherals such as printers, scanners or the like.

[0083] Execution of the instructions 1006 by the processing circuitry 1002, or storage of the instructions in the memory 1004, supports combinations of operations for implementing example implementations of the present disclosure. In this manner, an apparatus 1000 may comprise at least one processing circuitry and at least one memory coupled to the at least one processing circuitry, where the at least one processing circuitry is configured to execute instructions stored in the at least one memory. It will also be understood that one or more functions, and combinations of functions, may be implemented by special purpose hardware-based computer systems and / or processing circuitry which perform the specified functions, or combinations of special purpose hardware and program code instructions.

[0084] Some example implementations of the present disclosure may also be carried out in the form of a computer process defined by one or more computer programs or portions thereof. Example implementations of the present disclosure may be carried out by executing at least one portion of a computer program comprising instructions. The computer program may be in source code form, object code form, or in some intermediate form. The computer program may be stored in a computer-readable medium that is readable by a computer, processing circuitry or other suitable apparatus. As indicated above, for example, the computer program may be stored in a memory, such as a computer-readable storage medium. Additionally or alternatively, for example, the computer program may be stored in a computer-readable transmission medium. The coding of software for carrying out example implementations of the present disclosure is well within the scope of a person of ordinary skill in the art.

[0085] As will be appreciated, any suitable instructions may be loaded onto a computer, a processing circuitry or other programmable apparatus from a memory or a computer-readable medium (e.g., computer-readable storage medium, computer-readable transmission medium) to produce a particular machine, such that the particular machine becomes a means for implementing the functions specified herein. The instructions may also be stored in a computer-readable medium that can direct a computer, a processing circuitry or other programmable apparatus to function in a particular manner to thereby generate a particular machine or particular article of manufacture. In some examples, the instructions stored in the computer-readable medium may produce an article of manufacture, where the article of manufacture becomes a means for implementing functions described herein. The instructions may be retrieved from a computer-readable medium and loaded into a computer, processing circuitry or other programmable apparatus to configure the computer, processing circuitry or other programmable apparatus to execute operations to be performed on or by the computer, processing circuitry or other programmable apparatus.

[0086] Retrieval, loading and execution of instructions comprising program code instructions may be performed sequentially such that one instruction is retrieved, loaded and executed at a time. In some example implementations, retrieval, loading and / or execution may be performed in parallel such that multiple instructions are retrieved, loaded, and / or executed together. Execution of the program code instructions may produce a computer-implemented process such that the instructions executed by the computer, processing circuitry or other programmable apparatus provide operations for implementing functions described herein.

[0087] As explained above and reiterated below, the present disclosure includes, without limitation, the following example implementations.

[0088] Clause 1. An apparatus implemented by a user equipment (UE) of a first type, the apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: select a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type; perform a validation of one or more of the second PRACH occasions, the validation of each second PRACH occasion of the one or more of the second PRACH occasions performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain; and transmit a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions.

[0089] Clause 2. The apparatus of clause 1, wherein the SSB is one of a plurality of SSBs associated with a plurality of beams of a cell, and wherein the apparatus caused to perform the validation includes the apparatus caused to: determine a second PRACH occasion of the one or more second PRACH occasions overlaps an adjacent one of the first PRACH occasions in the time domain but not in the frequency domain; and determine a capability of the cell to create multiple ones of the plurality of beams in each time instance in the time domain, and in one or more frequency instances in the frequency domain, and that the second PRACH occasion is thereby valid.

[0090] Clause 3. The apparatus of clause 2, wherein the capability of the cell is determined based on parameters of a configuration of PRACH resources that define the first PRACH occasions, and wherein the parameters of the configuration include a first parameter that indicates a number of the plurality of SSBs mapped to each PRACH occasion, and a second parameter that includes a number of PRACH occasions allocated in the frequency domain in one time instance in the time domain.

[0091] Clause 4. The apparatus of clause 3, wherein the apparatus caused to determine the capability of the cell includes the apparatus caused to determine that a product of the parameters is greater than one.

[0092] Clause 5. The apparatus of any of clauses 1 to 4, wherein the apparatus caused to perform the validation includes the apparatus caused to: determine a second PRACH occasion of the one or more second PRACH occasions does not overlap an adjacent one of the first PRACH occasions in either the time domain or the frequency domain; and determine the second PRACH occasion is separated from the adjacent one of the PRACH occasions by at least specified number of symbols in the time domain, and that the second PRACH occasion is thereby valid.

[0093] Clause 6. The apparatus of any of clauses 1 to 5, wherein the apparatus caused to perform the validation includes the apparatus caused to determine a second PRACH occasion of the one or more second PRACH occasions fully overlaps an adjacent one of the first PRACH occasions in both the time domain and the frequency domain, and that the second PRACH occasion is thereby invalid.

[0094] Clause 7. The apparatus of any of clauses 1 to 6, wherein the apparatus caused to perform the validation includes the apparatus caused to: perform the validation of a number of the second PRACH occasions, including at least an earliest one and a next earliest one of the second PRACH occasions; and identify an earliest one of the number of the second PRACH occasions that is an earliest valid one of the number of the second PRACH occasions, and wherein the random access preamble is transmitted at the earliest PRACH occasion among the first PRACH occasions and the earliest valid one of the number of the second PRACH occasions.

[0095] Clause 8. The apparatus of any of clauses 1 to 7, wherein the apparatus caused to perform the validation includes the apparatus caused to: identify that an earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions is an earliest one of the second PRACH occasions; perform the validation of the earliest one of the second PRACH occasions; and when the earliest one of the second PRACH occasions is invalid, identify a next earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions; and when the next earliest PRACH occasion is a next earliest one of the second PRACH occasions, perform the validation of the next earliest one of the second PRACH occasions.

[0097] Clause 9. An apparatus implemented by a user equipment (UE) of a first type, the apparatus comprising: means for selecting a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type; means for performing a validation of one or more of the second PRACH occasions, the validation of each second PRACH occasion of the one or more of the second PRACH occasions performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain; and means for transmitting a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions.

[0098] Clause 10. The apparatus of clause 9, wherein the SSB is one of a plurality of SSBs associated with a plurality of beams of a cell, and wherein the means for performing the validation comprises: means for determining a second PRACH occasion of the one or more second PRACH occasions overlaps an adjacent one of the first PRACH occasions in the time domain but not in the frequency domain; and means for determining a capability of the cell to create multiple ones of the plurality of beams in each time instance in the time domain, and in one or more frequency instances in the frequency domain, and that the second PRACH occasion is thereby valid.

[0099] Clause 11. The apparatus of clause 10, wherein the capability of the cell is determined based on parameters of a configuration of PRACH resources that define the first PRACH occasions, and wherein the parameters of the configuration include a first parameter that indicates a number of the plurality of SSBs mapped to each PRACH occasion, and a second parameter that includes a number of PRACH occasions allocated in the frequency domain in one time instance in the time domain.

[0100] Clause 12. The apparatus of clause 11, wherein the means for determining the capability of the cell comprises means for determining that a product of the parameters is greater than one.

[0101] Clause 13. The apparatus of any of clauses 9 to 12, wherein the means for performing the validation comprises: means for determining a second PRACH occasion of the one or more second PRACH occasions does not overlap an adjacent one of the first PRACH occasions in either the time domain or the frequency domain; and means for determining the second PRACH occasion is separated from, the adjacent one of the PRACH occasions by at least specified number of symbols in the time domain, and that the second PRACH occasion is thereby valid.

[0102] Clause 14. The apparatus of any of clauses 9 to 13, wherein the means for performing the validation comprises means for determining a second PRACH occasion of the one or more second PRACH occasions fully overlaps an adjacent one of the first PRACH occasions in both the time domain and the frequency domain, and that the second PRACH occasion is thereby invalid.

[0103] Clause 15. The apparatus of any of clauses 9 to 14, wherein the means for performing the validation comprises: means for performing the validation of a number of the second PRACH occasions, including at least an earliest one and a next earliest one of the second PRACH occasions; and means for identifying an earliest one of the number of the second PRACH occasions that is an earliest valid one of the number of the second PRACH occasions, and wherein the random access preamble is transmitted at the earliest PRACH occasion among the first PRACH occasions and the earliest valid one of the number of the second PRACH occasions.

[0104] Clause 16. The apparatus of any of clauses 9 to 15, wherein the means for performing the validation comprises: means for identifying that an earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions is an earliest one of the second PRACH occasions; means for performing the validation of the earliest one of the second PRACH occasions; and when the earliest one of the second PRACH occasions is invalid, means for identifying a next earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions; and when the next earliest PRACH occasion is a next earliest one of the second PRACH occasions, means for performing the validation of the next earliest one of the second PRACH occasions.

[0105] Clause 17. A method performed by a user equipment (UE) of a first type, the method comprising: selecting a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type; performing a validation of one or more of the second PRACH occasions, the validation of each second PRACH occasion of the one or more of the second PRACH occasions performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain; and transmitting a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions.

[0106] Clause 18. The method of clause 17, wherein the SSB is one of a plurality of SSBs associated with a plurality of beams of a cell, and wherein performing the validation comprises: determining a second PRACH occasion of the one or more second PRACH occasions overlaps an adjacent one of the first PRACH occasions in the time domain but not in the frequency domain; and determining a capability of the cell to create multiple ones of the plurality of beams in each time instance in the time domain, and in one or more frequency instances in the frequency domain, and that the second PRACH occasion is thereby valid.

[0107] Clause 19. The method of clause 18, wherein the capability of the cell is determined based on parameters of a configuration of PRACH resources that define the first PRACH occasions, and wherein the parameters of the configuration include a first parameter that indicates a number of the plurality of SSBs mapped to each PRACH occasion, and a second parameter that includes a number of PRACH occasions allocated in the frequency domain in one time instance in the time domain.

[0108] Clause 20. The method of clause 19, wherein determining the capability of the cell comprises determining that a product of the parameters is greater than one.

[0109] Clause 21. The method of any of clauses 17 to 20, wherein performing the validation comprises: determining a second PRACH occasion of the one or more second PRACH occasions does not overlap an adjacent one of the first PRACH occasions in either the time domain or the frequency domain; and determining the second PRACH occasion is separated from the adjacent one of the PRACH occasions by at least specified number of symbols in the time domain, and that the second PRACH occasion is thereby valid.

[0110] Clause 22. The method of any of clauses 17 to 21, wherein performing the validation comprises determining a second PRACH occasion of the one or more second PRACH occasions fully overlaps an adjacent one of the first PRACH occasions in both the time domain and the frequency domain, and that the second PRACH occasion is thereby invalid.

[0111] Clause 23. The method of any of clauses 17 to 22, wherein performing the validation comprises: performing the validation of a number of the second PRACH occasions, inclu ding at least an earliest one and a next earliest one of the second PRACH occasions; and identifying an earliest one of the number of the second PRACH occasions that is an earliest valid one of the number of the second PRACH occasions, and wherein the random access preamble is transmitted at the earliest PRACH occasion among the first PRACH occasions and the earliest valid one of the number of the second PRACH occasions.

[0112] Clause 24. The method of any of clauses 17 to 23, wherein performing the validation comprises: identifying that an earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions is an earliest one of the second PRACH occasions; performing the validation of the earliest one of the second PRACH occasions; and when the earliest one of the second PRACH occasions is invalid, identifying a next earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions; and when the next earliest PRACH occasion is a next earliest one of the second PRACH occasions, performing the validation of the next earliest one of the second PRACH occasions.

[0113] Clause 25. A computer-readable storage medium implemented at a user equipment (UE) of a first type, the computer-readable storage medium being non-transitory and having instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: select a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type; perform a validation of one or more of the second PRACH occasions, the validation of each second PRACH occasion of the one or more of the second PRACH occasions performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain; and transmit a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions.

[0114] Clause 26. The computer-readable storage medium of clause 25, wherein the SSB is one of a plurality of SSBs associated with a plurality of beams of a cell, and wherein the apparatus caused to perform the validation includes the apparatus caused to: determine a second PRACH occasion of the one or more second PRACH occasions overlaps an adjacent one of the first PRACH occasions in the time domain but not in the frequency domain; and determine a capability of the cell to create multiple ones of the plurality of beams in each time instance in the time domain, and in one or more frequency instances in the frequency domain, and that the second PRACH occasion is thereby valid.

[0115] Clause 27. The computer-readable storage medium of clause 26, wherein the capability of the cell is determined based on parameters of a configuration of PRACH resources that define the first PRACH occasions, and wherein the parameters of the configuration include a first parameter that indicates a number of the plurality of SSBs mapped to each PRACH occasion, and a second parameter that includes a number of PRACH occasions allocated in the frequency domain in one time instance in the time domain.

[0116] Clause 28. The computer-readable storage medium of clause 27, wherein the apparatus caused to determine the capability of the cell includes the apparatus caused to determine that a product of the parameters is greater than one.

[0117] Clause 29. The computer-readable storage medium of any of clauses 25 to 28, wherein the apparatus caused to perform the validation includes the apparatus caused to: determine a second PRACH occasion of the one or more second PRACH occasions does not overlap an adjacent one of the first PRACH occasions in either the time domain or the frequency domain; and determine the second PRACH occasion is separated from the adjacent one of the PRACH occasions by at least specified number of symbols in the time domain, and that the second PRACH occasion is thereby valid.

[0118] Clause 30. The computer-readable storage medium of any of clauses 25 to 29, wherein the apparatus caused to perform the validation includes the apparatus caused to determine a second PRACH occasion of the one or more second PRACH occasions fully overlaps an adjacent one of the first PRACH occasions in both the time domain and the frequency domain, and that the second PRACH occasion is thereby invalid.

[0119] Clause 31. The computer-readable storage medium of any of clauses 25 to 30, wherein the apparatus caused to perform the validation includes the apparatus caused to: perform the validation of a number of the second PRACH occasions, including at least an earliest one and a next earliest one of the second PRACH occasions; and identify an earliest one of the number of the second PRACH occasions that is an earliest valid one of the number of the second PRACH occasions, and wherein the random access preamble is transmitted at the earliest PRACH occasion among the first PRACH occasions and the earliest valid one of the number of the second PRACH occasions.

[0120] Clause 32. The computer-readable storage medium of any of clauses 25 to 31, wherein the apparatus caused to perform the validation includes the apparatus caused to: identify that an earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions is an earliest one of the second PRACH occasions; perform the validation of the earliest one of the second PRACH occasions; and when the earliest one of the second PRACH occasions is invalid, identify a next earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions; and when the next earliest PRACH occasion is a next earliest one of the second PRACH occasions, perform, the validation of the next earliest one of the second PRACH occasions.

[0121] Clause 33. An apparatus comprising means for performing the method of any of clauses 17 to 24.

[0122] Clause 34. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 17 to 24.

[0123] Clause 35. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 17 to 24.

[0124] Clause 36. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 17 to 24.

[0125] Many modifications and other implementations of the disclosure set forth herein will come to mind to one skilled in the art to which the disclosure pertains having the benefit of the teachings presented in the foregoing description and the associated figures. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed and that modifications and other implementations are intended to be included within the scope of the appended claims. Moreover, although the foregoing description and the associated figures describe example implementations in the context of certain example combinations of elements and / or functions, it should be appreciated that different combinations of elements and / or functions may be provided by alternative implementations without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and / or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. An apparatus implemented by a user equipment (UE) of a first type, the apparatus comprising:means for selecting a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configured for UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type;means for performing a validation of one or more of the second PRACH occasions, the validation of each second PRACH occasion of the one or more of the second PRACH occasions performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain; andmeans for transmitting a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions.

2. The apparatus of claim 1, wherein the SSB is one of a plurality of SSBs associated with a plurality of beams of a cell, and wherein the means for performing the validation comprises:means for determining a second PRACH occasion of the one or more second PRACH occasions overlaps an adjacent one of the first PRACH occasions in the time domain but not in the frequency domain; andmeans for determining a capability of the cell to create multiple ones of the plurality of beams in each time instance in the time domain, and in one or more frequency instances in the frequency domain, and that the second PRACH occasion is thereby valid.

3. The apparatus of claim 2, wherein the capability of the cell is determined based on parameters of a configuration of PRACH resources that define the first PRACH occasions, andwherein the parameters of the configuration include a first parameter that indicates a number of the plurality of SSBs mapped to each PRACH occasion, and a second parameter that includes a number of PRACH occasions allocated in the frequency domain in one time instance in the time domain.

4. The apparatus of claim 3, wherein the means for determining the capability of the cell comprises means for determining that a product of the parameters is greater than one.

5. The apparatus of any of claims 1 to 4, wherein the means for performing the validation comprises:means for determining a second PRACH occasion of the one or more second PRACH occasions does not overlap an adjacent one of the first PRACH occasions in either the time domain or the frequency domain; andmeans for determining the second PRACH occasion is separated from the adjacent one of the PRACH occasions by at least specified number of symbols in the time domain, and that the second PRACH occasion is thereby valid.

6. The apparatus of any of claims 1 to 5, wherein the means for performing the validation comprises means for determining a second PRACH occasion of the one or more second PRACH occasions fully overlaps an adjacent one of the first PRACH occasions in both the time domain and the frequency domain, and that the second PRACH occasion is thereby invalid.

7. The apparatus of any of claims 1 to 6, wherein the means for performing the validation comprises:means for performing the validation of a number of the second PRACH occasions, including at least an earliest one and a next earliest one of the second PRACH occasions; andmeans for identifying an earliest one of the number of the second PRACH occasions that is an earliest valid one of the number of the second PRACH occasions, andwherein the random access preamble is transmitted at the earliest PRACH occasion among the first PRACH occasions and the earliest valid one of the number of the second PRACH occasions.

8. The apparatus of any of claims 1 to 7, wherein the means for performing the validation comprises:means for identifying that an earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions is an earliest one of the second PRACH occasions;means for performing the validation of the earliest one of the second PRACH occasions; and when the earliest one of the second PRACH occasions is invalid,means for identifying a next earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions; and when the next earliest PRACH occasion is a next earliest one of the second PRACH occasions,means for performing the validation of the next earliest one of the second PRACH occasions.

9. A method performed by a user equipment (UE) of a first type, the method comprising:selecting a synchronization signal block (SSB) that is mapped to first physical random access channel (PRACH) occasions configuredfor UEs of the first type and UEs of a second type, and mapped to second PRACH occasions configured for UEs of the first type;performing a validation of one or more of the second PRACH occasions, the validation of each second PRACH occasion of the one or more of the second PRACH occasions performed based on proximity to an adjacent one of the first PRACH occasions in a time domain and a frequency domain; andtransmitting a random access preamble at an earliest PRACH occasion among the first PRACH occasions and any valid ones of the one or more of the second PRACH occasions.

10. The method of claim 9, wherein the SSB is one of a plurality of SSBs associated with a plurality of beams of a cell, and wherein performing the validation comprises:determining a second PRACH occasion of the one or more second PRACH occasions overlaps an adjacent one of the first PRACH occasions in the time domain but not in the frequency domain; anddetermining a capability of the cell to create multiple ones of the plurality of beams in each time instance in the time domain, and in one or more frequency instances in the frequency domain, and that the second PRACH occasion is thereby valid.

11. The method of claim 10, wherein the capability of the cell is determined based on parameters of a configuration of PRACH resources that define the first PRACH occasions, andwherein the parameters of the configuration include a first parameter that indicates a number of the plurality of SSBs mapped to each PRACH occasion, and a second parameter that includes a number of PRACH occasions allocated in the frequency domain in one time instance in the time domain.

12. The method of claim 11, wherein determining the capability of the cell comprises determining that a product of the parameters is greater than one.

13. The method of any of claims 9 to 12, wherein performing the validation comprises:determining a second PRACH occasion of the one or more second PRACH occasions does not overlap an adjacent one of the first PRACH occasions in either the time domain or the frequency domain; anddetermining the second PRACH occasion is separated from the adjacent one of the PRACH occasions by at least specified number of symbols in the time domain, and that the second PRACH occasion is thereby valid.

14. The method of any of claims 9 to 13, wherein performing the validation comprises determining a second PRACH occasion of the one or more second PRACH occasions fully overlaps an adjacent one of the first PRACH occasions in both the time domain and the frequency domain, and that the second PRACH occasion is thereby invalid.

15. The method of any of claims 9 to 14, wherein performing the validation comprises:performing the validation of a number of the second PRACH occasions, including at least an earliest one and a next earliest one of the second PRACH occasions; andidentifying an earliest one of the number of the second PRACH occasions that is an earliest valid one of the number of the second PRACH occasions, andwherein the random access preamble is transmitted at the earliest PRACH occasion among the first PRACH occasions and the earliest valid one of the number of the second PRACH occasions.

16. The method of any of claims 9 to 15, wherein performing the validation comprises:identifying that an earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions is an earliest one of the second PRACH occasions;performing the validation of the earliest one of the second PRACH occasions; and when the earliest one of the second PRACH occasions is invalid,identifying a next earliest PRACH occasion among the first PRACH occasions and the second PRACH occasions; and when the next earliest PRACH occasion is a next earliest one of the second PRACH occasions,performing the validation of the next earliest one of the second PRACH occasions.

17. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of claims 9 to 16.

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