Patent Description:
<CIT> describes a communication method for configuring subframes dedicate for a backhaul link, wherein access of a legacy mobile station is restricted for at least part of the subframes.

In some aspects, a method of wireless communication, performed by a user equipment functionality (UEF) entity, may include identifying a scaling factor associated with determining a periodicity of backhaul physical random access channel (PRACH) resources; and determining, based at least in part on the scaling factor, the periodicity of the backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is extended as compared to a periodicity of access PRACH resources.

In some aspects, a UEF entity for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to identify a scaling factor associated with determining a periodicity of backhaul PRACH resources; and determine, based at least in part on the scaling factor, the periodicity of the backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is extended as compared to a periodicity of access PRACH resources.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UEF entity, may cause the one or more processors to identify a scaling factor associated with determining a periodicity of backhaul PRACH resources; and determine, based at least in part on the scaling factor, the periodicity of the backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is extended as compared to a periodicity of access PRACH resources.

In some aspects, an apparatus for wireless communication may include means for identifying a scaling factor associated with determining a periodicity of backhaul PRACH resources; and means for determining, based at least in part on the scaling factor, the periodicity of the backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is extended as compared to a periodicity of access PRACH resources.

In some aspects, a method of wireless communication, performed by an ANF entity, may include identifying a scaling factor to be used by a UEF entity in association with determining a periodicity of backhaul physical random access channel (PRACH) resources, wherein the periodicity of the backhaul PRACH resources is to be extended as compared to a periodicity of access PRACH resources; and signaling the scaling factor to the UEF entity.

In some aspects, an ANF entity for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to identify a scaling factor to be used by a UEF entity in association with determining a periodicity of backhaul physical random access channel (PRACH) resources, wherein the periodicity of the backhaul PRACH resources is to be extended as compared to a periodicity of access PRACH resources; and signal the scaling factor to the UEF entity.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of an ANF entity, may cause the one or more processors to identify a scaling factor to be used by a UEF entity in association with determining a periodicity of backhaul physical random access channel (PRACH) resources, wherein the periodicity of the backhaul PRACH resources is to be extended as compared to a periodicity of access PRACH resources; and signal the scaling factor to the UEF entity.

In some aspects, an apparatus for wireless communication may include means for identifying a scaling factor to be used by a UEF entity in association with determining a periodicity of backhaul physical random access channel (PRACH) resources, wherein the periodicity of the backhaul PRACH resources is to be extended as compared to a periodicity of access PRACH resources; and means for signaling the scaling factor to the UEF entity.

In some aspects, a method of wireless communication, performed by an access node functionality (ANF) entity, may include configuring a time offset of backhaul physical random access channel (PRACH) resources; and transmitting information that identifies the time offset, wherein the time offset is different from a time offset that is identified based at least in part on a PRACH configuration index.

In some aspects, an ANF entity for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to configure a time offset of backhaul physical random access channel (PRACH) resources; and transmit information that identifies the time offset, wherein the time offset is different from a time offset that is identified based at least in part on a PRACH configuration index.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of an ANF entity, may cause the one or more processors to configure a time offset of backhaul physical random access channel (PRACH) resources; and transmit information that identifies the time offset, wherein the time offset is different from a time offset that is identified based at least in part on a PRACH configuration index.

In some aspects, an apparatus for wireless communication may include means for configuring a time offset of backhaul physical random access channel (PRACH) resources; and means for transmitting information that identifies the time offset, wherein the time offset is different from a time offset that is identified based at least in part on a PRACH configuration index.

In some aspects, a method of wireless communication, performed by a UEF entity, may include receiving information that identifies a time offset associated with backhaul physical random access channel (PRACH) resources, wherein the time offset is different from a time offset that is identified based at least in part on a PRACH configuration index; identifying a set of backhaul PRACH resources based at least in part on the time offset; and transmitting a RACH transmission using the identified set of back backhaul PRACH resources.

In some aspects, a UEF entity for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive information that identifies a time offset associated with backhaul physical random access channel (PRACH) resources, wherein the time offset is different from a time offset that is identified based at least in part on a PRACH configuration index; identify a set of backhaul PRACH resources based at least in part on the time offset; and transmit a RACH transmission using the identified set of back backhaul PRACH resources.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UEF entity, may cause the one or more processors to receive information that identifies a time offset associated with backhaul physical random access channel (PRACH) resources, wherein the time offset is different from a time offset that is identified based at least in part on a PRACH configuration index; identify a set of backhaul PRACH resources based at least in part on the time offset; and transmit a RACH transmission using the identified set of back backhaul PRACH resources.

In some aspects, an apparatus for wireless communication may include means for receiving information that identifies a time offset associated with backhaul physical random access channel (PRACH) resource, wherein the time offset is different from a time offset that is identified based at least in part on a PRACH configuration index s; means for identifying a set of backhaul PRACH resources based at least in part on the time offset; and means for transmitting a RACH transmission using the identified set of back backhaul PRACH resources.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, and processing system as substantially described herein with reference to and as illustrated by the accompanying drawings, specification, and appendices.

Each of the figures is provided for the purpose of illustration and description.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with physical random access channel (PRACH) configuration periodicity extension for backhaul links, as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively.

In some aspects, base station <NUM> (e.g., a base station that operates with UE functionality (UEF)) may include means for identifying a scaling factor associated with determining a periodicity of backhaul PRACH resources; means for determining, based at least in part on the scaling factor, the periodicity of the backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is extended as compared to a periodicity of access PRACH resources; and/or the like. In some aspects, such means may include one or more components of base station <NUM> described in connection with <FIG>.

In some aspects, a base station <NUM> (e.g., a base station that operates with access node functionality (ANF)) may include means for identifying a scaling factor to be used by a UEF entity (e.g., a base station <NUM> with UEF) in association with determining a periodicity of backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is to be extended as compared to a periodicity of access PRACH resources; means for signaling the scaling factor to the UEF entity; and/or the like. In some aspects, such means may include one or more components of base station <NUM> described in connection with <FIG>.

In some aspects, a base station <NUM> (e.g., a base station <NUM> that operates with ANF) may include means for configuring a time offset of backhaul PRACH resources; means for transmitting information that identifies the offset, wherein the time offset is different from a time offset that is identified based at least in part on a PRACH configuration index; and/or the like. In some aspects, such means may include one or more components of base station <NUM> described in connection with <FIG>.

In some aspects, a base station <NUM> (e.g., a base station <NUM> that operates with UEF) may include means for receiving information that identifies a time offset associated with backhaul PRACH resources, wherein the time offset is different from a time offset that is identified based at least in part on a PRACH configuration index; means for identifying a set of backhaul PRACH resources based at least in part on the time offset; means for transmitting a RACH transmission using the identified set of backhaul PRACH resources; and/or the like. In some aspects, such means may include one or more components of base station <NUM> described in connection with <FIG>.

<FIG> shows an example frame structure <NUM> for FDD in a telecommunications system (e.g., NR). The transmission time line for each of the downlink and uplink may be partitioned into units of radio frames (sometimes referred to as frames). Each subframe may have a predetermined duration (e.g., <NUM>) and may include a set of slots (e.g., <NUM>m slots per subframe are shown in <FIG>, where m is a numerology used for a transmission, such as <NUM>, <NUM>,<NUM>, <NUM>, <NUM>, and/or the like). In some aspects, a scheduling unit for the FDD may frame-based, subframe-based, slot-based, symbol-based, and/or the like.

Other examples are possible and may differ from what was described with regard to <FIG> and <FIG>.

Each resource block may cover a set to of subcarriers (e.g., <NUM> subcarriers) in one slot and may include a number of resource elements.

An interlace structure may be used for each of the downlink and uplink for FDD in certain telecommunications systems (e.g., NR). For example, Q interlaces with indices of <NUM> through Q - <NUM> may be defined, where Q may be equal to <NUM>, <NUM>, <NUM>, <NUM>, or some other value. Each interlace may include slots that are spaced apart by Q frames. In particular, interlace q may include slots q, q + Q, q + 2Q, etc., where q ∈ {<NUM>,.

<FIG> is a diagram illustrating examples <NUM> of radio access networks, in accordance with various aspects of the disclosure.

As shown by reference number <NUM>, a traditional (e.g., <NUM>, <NUM>, LTE, etc.) radio access network may include multiple base stations <NUM> (e.g., access nodes (AN)), where each base station <NUM> communicates with a core network via a wired backhaul link <NUM>, such as a fiber connection. A base station <NUM> may communicate with a UE <NUM> via an access link <NUM>, which may be a wireless link. In some aspects, a base station <NUM> shown in <FIG> may correspond to a base station <NUM> shown in <FIG>. Similarly, a UE <NUM> shown in <FIG> may correspond to a UE <NUM> shown in <FIG>.

As shown by reference number <NUM>, a radio access network may include a wireless backhaul network, where at least one base station is an anchor base station <NUM> that communicates with a core network via a wired backhaul link <NUM>, such as a fiber connection. The wireless backhaul network may include one or more non-anchor base stations <NUM> that communicate directly with or indirectly with (e.g., via one or more non-anchor base stations <NUM>) the anchor base station <NUM> via one or more backhaul links <NUM> to form a backhaul path to the core network for carrying backhaul traffic. Backhaul link <NUM> may be a wireless link. Anchor base station(s) <NUM> and/or non-anchor base station(s) <NUM> may communicate with one or more UEs <NUM> via access links <NUM>, which may be wireless links for carrying access traffic. In some aspects, an anchor base station <NUM> and/or a non-anchor base station <NUM> shown in <FIG> may correspond to a base station <NUM> shown in <FIG>. Similarly, a UE <NUM> shown in <FIG> may correspond to a UE <NUM> shown in <FIG>.

As shown by reference number <NUM>, in some aspects, a radio access network that includes a wireless backhaul network may utilize millimeter wave technology and/or directional communications (e.g., beamforming, precoding, and/or the like) for communications between base stations and/or UEs (e.g., between two base stations, between two UEs, and/or between a base station and a UE). For example, the wireless backhaul links <NUM> between base stations may use millimeter waves to carry information and/or may be directed toward a target base station using beamforming, precoding, and/or the like. Similarly, the wireless access links <NUM> between a UE and a base station may use millimeter waves and/or may be directed toward a target wireless node (e.g., a UE and/or a base station). In this way, inter-link interference may be reduced.

<FIG> is a diagram illustrating an example <NUM> of resource partitioning in a wireless backhaul network, in accordance with various aspects of the disclosure.

As shown in <FIG>, an anchor base station <NUM> may be connected to a core network <NUM> via a wired backhaul link <NUM>, such as a fiber connection. As further shown, non-anchor base stations <NUM> may communicate directly with anchor base station <NUM> via wireless backhaul links <NUM>. In some aspects, one or more non-anchor base stations may communicate indirectly with anchor base station <NUM> via multiple wireless backhaul links (e.g., via one or more other non-anchor base stations). For example, and as shown, a first set of non-anchor base stations <NUM> may communicate indirectly with anchor base station <NUM> via a wireless backhaul link <NUM> and a wireless backhaul link <NUM>. As further shown, a second set of non-anchor base stations <NUM> may communicate indirectly with anchor base station <NUM> via a wireless backhaul link <NUM>, a wireless backhaul link <NUM>, and a wireless backhaul link <NUM>.

As further shown, a UE <NUM> may communicate with anchor base station <NUM> via a wireless access link <NUM>, a UE <NUM> may communicate with a non-anchor base station <NUM> via a wireless access link <NUM>, and a UE <NUM> may communicate with a non-anchor base station <NUM> via a wireless access link <NUM>.

In some aspects, an index (e.g., a color index) may be assigned to a wireless link and/or a wireless node (e.g., a base station or a UE). The index may indicate one or more resources allocated to a wireless node for communication via the wireless link. For example, and as shown, a first index <NUM> may be associated with transmission time intervals (TTIs) <NUM>, <NUM>, and <NUM>, and a second index <NUM> may be associated with TTIs <NUM> and <NUM>. As indicated by light gray lines in <FIG>, the first index <NUM> may be assigned to wireless backhaul links <NUM> and <NUM> and wireless access links <NUM> and <NUM>. Thus, information may be transmitted over these links during TTIs <NUM>, <NUM>, and <NUM>, and not during TTIs <NUM> and <NUM>. Similarly, and as indicated by dark gray lines in <FIG>, the second index <NUM> may be assigned to wireless backhaul links <NUM> and wireless access links <NUM>. Thus, information may be transmitted over these links during TTIs <NUM> and <NUM>, and not during TTIs <NUM>, <NUM>, and <NUM>. In this way, wireless nodes may coordinate communication such that a wireless node is not configured to transmit and receive data at the same time.

While the resources are shown as time resources, additionally, or alternatively, an index may be associated with a frequency resource. Furthermore, the configuration of base stations and UEs in <FIG> is shown as an example, and other examples are possible.

In an integrated access and backhaul (IAB) network, such as those described in association with <FIG> and <FIG>, a base station is typically connected, via a wireless backhaul link, to a nearest neighbor base station. However, in some cases, the base station may need to connect to a base station that is a comparatively further distance away than the nearest neighbor base station (e.g., for load balancing in a scenario where the nearest neighbor base station is using an amount of resources for access transmissions such that the nearest neighbor base station cannot transport backhaul transmissions). Thus, backhaul random access channel (RACH) design may need to support different (e.g., higher) round trip times and link gains as compared to access RACH design.

Further, in the IAB network, a given base station may receive both backhaul RACH transmissions and access RACH transmissions. In some cases, differences between link gains of backhaul RACH and access RACH may exist. Such differences may result from, for example, different numbers of transmit antennas used for backhaul RACH as compared to access RACH, different transmission powers used for backhaul RACH as compared to access RACH, different amounts of hand and/or body loss experienced by backhaul RACH as compared to access RACH, different path losses experienced by backhaul RACH as compared to access RACH, and/or the like.

Additionally, a number of supported cyclic shifts for each Zadoff-Chu (ZC) root sequence associated with RACH transmission should be designed such that a gap between neighbouring cyclic shifts can handle a desired round trip distance. For example, assume that an IAB network is to be designed such that base stations that are separated by M (M ≥ <NUM>) hops are to be able to transmit RACH to one another. In order to handle such a case, a number of supported cyclic shifts for each ZC root sequence in backhaul RACH is [<NUM>/(<NUM>×M)]th of that of access RACH. As a particular example, if an IAB network is to be designed such that base stations that are separated by <NUM> hops are to be able to transmit RACH to one another, then a number of supported cyclic shifts for each ZC root sequence in backhaul RACH is <NUM>/6th (e.g., <NUM>/(<NUM>×<NUM>) = <NUM>/6th ) of that of access RACH. Hence, if access links and backhaul links use the same time-frequency resources for RACH transmission, supportable cyclic shifts for RACH transmission decrease significantly. This requires the IAB network to use more ZC root sequences in order to support a given number of RACH preambles (e.g., <NUM> RACH preambles) in one RACH occasion, which causes higher interference across RACH transmissions in neighbouring cells.

This also leads to a trade-off when the IAB network configures access RACH preambles and backhaul RACH preambles in the same time-frequency resources. For example, if the network configures RACH preamble format B4 (e.g., with <NUM> repetitions and a <NUM> microsecond (µs) cyclic prefix duration with <NUM> kilohertz (kHz) subcarrier spacing (SCS)) in order to satisfy an access link budget requirement, the network can only support up to <NUM> kilometers (km) of round trip time distance in backhaul links. Conversely, if the network configures RACH preamble format C2 (e.g., with <NUM> repetitions and a <NUM> cyclic prefix duration with <NUM> SCS) in order to meet a <NUM> round trip time distance in backhaul links, the network loses approximately <NUM> decibels (dB) in access RACH link budget. In other words, if access links and backhaul links are to use the same time-frequency resources for RACH transmissions, the network has to trade-off between supporting higher distance in backhaul links and higher gain in access links.

Due to the above issues, a NR IAB network may be designed to support configuring access RACH occasions differently from backhaul RACH occasions (e.g., such that access RACH occasions and backhaul RACH occasions use different time-frequency resources). Here, a RACH occasion denotes a set of time-frequency resources for RACH transmissions, and a given set of time-frequency resources may be for contention based RACH or contention free RACH.

Notably, the capability to differently configure access RACH occasions and backhaul RACH occasions may require additional signaling by a given base station, while the given base station also needs to configure other/additional RACH occasions for backhaul RACH. However, since a given IAB node requiring a backhaul connection (e.g., a base station) will be relatively static (i.e., have low mobility) in most cases, configuration of contention based backhaul RACH occasions as frequently as contention based access RACH occasions may result in wasted network resources (e.g., since contention based backhaul RACH transmissions may be occurring less frequently). Hence, it may be advantageous for the IAB network to configure contention-based backhaul RACH occasions more infrequently than contention-based access RACH occasions.

Some aspects described herein describe identifying a scaling factor associated with determining a periodicity of backhaul physical RACH (PRACH) resources, and identifying the periodicity of the backhaul PRACH resources based at least in part on the scaling factor. In some aspects, the periodicity of the backhaul PRACH resources is extended as compared to a periodicity of access PRACH resources, as described below.

Further, a node in an IAB network cannot transmit PRACH to a parent node of the IAB node simultaneously with receiving RACH from a child node of the IAB node. Additionally, the PRACH resources among adjacent hops should be orthogonalized (e.g., in order to prevent the same set of resources from being used for communications with the parent node and the child node). However, this reduces flexibility of the IAB network to select PRACH configuration indices. For example, a pair of configuration indices that identify the same slot number for PRACH resources (e.g., a pair of configuration indices with overlapping PRACH resource slots) may not be selected in adjacent IAB network hops.

Some aspects described herein describe an IAB network configured to explicitly configure a system frame number (SFN) periodicity and a time offset of RACH resources of IAB nodes in order to orthogonalize RACH resources across adjacent IAB network hops.

<FIG> is a diagram illustrating an example <NUM> of determining a periodicity of backhaul physical RACH (PRACH) resources based at least in part on a scaling factor, and determining a time offset of the backhaul PRACH resources, in accordance with various aspects of the present disclosure. A new base station and/or a target base station, as described in association with <FIG>, may each correspond to a respective base station <NUM>, non-anchor base station <NUM>, non-anchor base station <NUM>/<NUM>/<NUM>, and/or the like. In some aspects, the new base station operates with a UE functionality (UEF). A wireless communication device that operates with UEF is herein referred to as a UEF entity. For example, the new base station may be used in a mobile termination (MT) of an IAB node (e.g., the new base station may be a scheduled entity for UE/MT of IAB). In some aspects, the target base station operates with an access node functionality (ANF). A wireless communication device that operates with ANF is herein referred to as an ANF entity. For example, the target base station may be a scheduler for a base station <NUM>.

As noted in <FIG>, the target base station is deployed within a wireless backhaul network (e.g., an IAB network), while the new base station is a base station that is being deployed in the wireless backhaul network (e.g., a base station that is not presently connected to the wireless backhaul network). For the purposes of example <NUM>, assume that the new base station is to identify a set of backhaul PRACH resources in which to transmit a random access message (e.g., MSG1) for initiating a RACH procedure associated with establishing a connection, via a wireless backhaul link, with the target base station.

As shown by reference number <NUM>, the new base station may determine a scaling factor and/or a time offset. The scaling factor may include a value (e.g., an integer value) based at least in part on which a periodicity of backhaul PRACH resources can be determined. In some aspects, the periodicity of the backhaul PRACH resources, to be determined by the new base station, is extended as compared to a periodicity of access PRACH resources, as described herein.

The time offset includes a time offset of PRACH resources. In some aspects, the IAB network (e.g., the target base station or another wireless communication device associated with the IAB network) may (e.g., explicitly) configure the time offset of the backhaul PRACH resources, and may transmit information that identifies the time offset to the new base station, as indicated in <FIG>. In some aspects, the time offset may be identified in terms of a number of radio frames, a number of slots, a number of subframes, a number of symbols, and/or the like. In some aspects, the time offset may be different from an time offset associated with a PRACH configuration index. In such a case, the time offset overrides the time offset that is associated with the PRACH configuration index, as described below.

In some aspects, as indicated in <FIG>, the new base station may determine the scaling factor and/or the time offset based at least in part on the scaling factor and/or the time offset, respectively, being signaled to the new base station (e.g., by the target base station). In some aspects, the scaling factor and/or the time offset may be signaled to the new base station via remaining minimum system information (RMSI), other system information (OSI), downlink control information (DCI), a medium access control (MAC) control element (MAC-CE), radio resource control (RRC) signaling, a handover command, and/or the like.

In some aspects, the scaling factor may be a fixed value. For example, in some aspects, the scaling factor may be defined in a specification associated with the IAB network, and this fixed value scaling factor may be configured on the new base station in accordance with the specification (e.g., such that information that identifies the scaling factor is stored or accessible by the new base station, without a need for the scaling factor to be signaled by the target base station).

As further shown in <FIG>, and by reference number <NUM>, the new base station may determine the periodicity of the backhaul PRACH resources based at least in part on the scaling factor.

In some aspects, the periodicity of the backhaul PRACH resources is associated with identifying a radio frame location of a set of backhaul PRACH resources (e.g., a set of resources that may be used by the new base station in order to transmit a backhaul RACH transmission).

In some aspects, the new base station may determine the periodicity of the backhaul PRACH resources based on a PRACH configuration index. For example, the new base station may determine a PRACH configuration index based at least in part on information carried in a system information block (e.g., SIB2) received by the new base station. The new base station may then determine (e.g., based on a PRACH configuration index table configured on the new base station) a periodicity of PRACH resources that corresponds to the PRACH configuration index. Here, the new base station may determine the periodicity of the backhaul PRACH resources based at least in part on applying the scaling factor to the periodicity of PRACH resources that corresponds to the PRACH configuration index.

As a particular example, assume that the new base station determines a scaling factor <NUM> and is signaled a PRACH configuration index that indicates that a PRACH resource periodicity of <NUM> (e.g., indicating that PRACH resources occur every <NUM> radio frames). Here, the new base station may determine the periodicity of the backhaul PRACH resources based on multiplying the scaling factor and the periodicity identified by the PRACH configuration index. Thus, in this example, the new base station may determine that backhaul PRACH resources occur every <NUM> radio frames (e.g., <NUM> × <NUM> = <NUM>). The new base station may determine particular locations of the backhaul PRACH resources, within a given radio frame, based at least in part on other information associated with the PRACH configuration index. Notably, as illustrated here, the periodicity of the backhaul RACH resources (e.g., occurring in every <NUM> radio frames) is extended as compared to the periodicity of access RACH resources (e.g., when the periodicity of access PRACH resources is to match the periodicity indicated by the PRACH configuration index). In this way, the scaling factor may be used to extend the periodicity of backhaul PRACH resources through signaling of a single value (i.e., the scaling factor), thereby reducing signaling overhead and without a need to reconfigure and/or redesign a PRACH configuration index table, while still allowing for differently configured backhaul PRACH resources.

According to the claimed invention, an ANF, entity configures a first time offset of backhaul PRACH resources; configures a scaling factor associated with a periodicity of the backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is to be determined based at least in part on multiplying the scaling factor and a periodicity of PRACH resources associated with a PRACH configuration index; and transmits information that identifies the first time offset and the scaling factor, wherein the first time offset is different from a second time offset that is identified based at least in part on the PRACH configuration index.

According to the claimed invention, a UEF entity receives information that identifies a first time offset associated with PRACH resources and a scaling factor associated with a first periodicity of the backhaul PRACH resources, wherein the first time offset is different from a second time offset that is identified based at least in part on a PRACH configuration index; determines the first periodicity based at least in part on multiplying the scaling factor and a second periodicity of PRACH resources associated with the PRACH configuration index; identifies a set of backhaul PRACH resources based at least in part on the first periodicity and the first time offset; and transmits a RACH transmission using the identified set of backhaul PRACH resources.

In some aspects, the periodicity of the backhaul PRACH resources is associated with repetition of a mapping pattern that associates synchronization signal blocks with PRACH resources. For example, the periodicity may identify an interval of time at which a mapping pattern, associating synchronization signal blocks with respective PRACH resources, is to repeat. In some aspects, the interval of time at which the mapping pattern is to repeat may be determined based at least in part on the scaling factor and a PRACH configuration period, as described below.

Generally, mapping synchronization signal blocks to PRACH resources is needed in order to allow a wireless communication device (e.g., a UE, a new base station) to indicate a synchronization signal block preferred by the wireless communication device. For example, a given synchronization signal block may correspond to a particular base station beam. Thus, by transmitting the RACH transmission (e.g., MSG1) in particular RACH resources that map to a preferred synchronization signal block, the wireless communication device indicates a base station beam to the target base station (e.g., such that the target base station can transmit a random access response (MSG2) using the indicated beam). However, the mapping pattern associated with mapping synchronization signal blocks to PRACH resources should repeat with an identifiable periodicity. Otherwise, the wireless communication device will be unable to determine which synchronization signal blocks are associated with particular PRACH resources and, thus, would be unable to indicate a preferred synchronization signal block.

Typically, the mapping pattern should repeat after an association period. The association period is equal to a PRACH configuration period multiplied by an integer number (e.g., a value that identifies a number of PRACH configuration periods). The association period used is equal to a minimum value, of a set of values, that satisfies a full mapping for transmitted synchronization signal blocks. For example, assume that a PRACH configuration period is <NUM> milliseconds (ms) and the set of possible values includes <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. Here, the synchronization signal block to PRACH resource mapping pattern may repeat after every <NUM> (e.g., <NUM> × <NUM> = <NUM>), every <NUM> (e.g., <NUM> × <NUM> = <NUM>), every <NUM> (e.g., <NUM> × <NUM> = <NUM>), every <NUM> (e.g., <NUM> × <NUM> = <NUM>), or every <NUM> (e.g., <NUM> × <NUM> = <NUM>). The repetition period for the mapping pattern may be selected as the minimum of these five durations that allows a full set of synchronization signal blocks to be mapped to respective PRACH resources. For example, assume the target base station transmits <NUM> synchronization signal blocks, and that <NUM> PRACH resources are configured within a given <NUM> PRACH configuration period. Thus, <NUM> PRACH resources are configured within <NUM> (e.g., one PRACH configuration period), <NUM> PRACH resources are configured within <NUM> (e.g., two PRACH configuration periods), and <NUM> PRACH resources are configured within <NUM> (e.g., four PRACH configuration periods). As such, a full synchronization signal block to PRACH resource mapping requires at least a four PRACH configuration periods, indicating that the mapping pattern should repeat after every <NUM>. Hence, the association period in this case is <NUM>.

In the case of backhaul PRACH resources, the repetition of the mapping pattern may be determined based at least in part on the scaling factor. For example, the new base station may determine the repetition of the mapping pattern (e.g., an interval at which the mapping pattern is to repeat) based at least in part on the scaling factor, a PRACH configuration period, and an integer value. For example, the new base station may determine the interval at which the mapping pattern is to repeat as an amount of time equal to a product of the scaling factor, the PRACH configuration period, and the integer value.

In some aspects, the repetition of the mapping pattern may be determined in accordance with the following table:.

where S represents the scaling factor by which the product of the PRACH configuration period and a given integer value is multiplied.

As a particular example, assume that the new base station determines a scaling factor of <NUM>, a PRACH configuration period of <NUM>, and a set of integer values including <NUM>, <NUM>, <NUM>, and <NUM>. Here, the new base station may determine that the synchronization signal block to PRACH resource mapping pattern may repeat every <NUM> (e.g., <NUM> × <NUM> × <NUM> = <NUM>), every <NUM> (e.g., <NUM> × <NUM> × <NUM> = <NUM>), every <NUM> (e.g., <NUM> × <NUM> × <NUM> = <NUM>), or every <NUM> (e.g., <NUM> × <NUM> × <NUM> = <NUM>). Here, the repetition period for the mapping pattern may be selected as the minimum of these five durations that allows a full set of synchronization signal blocks to be mapped to respective backhaul PRACH resources, as described above.

In some aspects, since RACH resources may get invalidated due to the presence of synchronization signal blocks or downlink resources, the association period may change over time. For example, during a first time period (e.g., from <NUM> to <NUM>) the association period might be <NUM>. However, during a second time period (e.g., from <NUM> to <NUM>), the association period can be, for example, equal to <NUM> or <NUM>. In order to reduce complexity arising from the irregularity of the association period over time, an "association pattern period" may be configured. The association pattern period is a period after which the synchronization signal block to RACH mapping is guaranteed to repeat, irrespective of how RACH resources get invalidated. In some aspects, the association pattern period may be equal to <NUM> in an access network.

In some aspects, the new base station may be configured such that the mapping pattern is guaranteed to repeat after an amount of time equal to a product of a fixed time value, configured on the new base station, and the scaling factor. In some aspects, the fixed time value may be, for example, <NUM>. Thus, in some aspects, the new base station may be configured such that the association pattern repeats (at most) every <NUM> × S ms, where S represents the scaling factor. Hence, the association pattern period might <NUM> x S ms in backhaul networks.

Thus, in some aspects, the association period and/or the association pattern period, associated with mapping synchronization signal blocks to PRACH resources, may be determined based at least in part on the scaling factor. For example, in some aspects, the association period may be determined such that a pattern between PRACH occasions and synchronization signal blocks repeats at an amount of time that is equal to or less than a product of a PRACH configuration period and the scaling factor. As another example, in some aspects, the association pattern period may be determined based at least in part on the scaling factor, a PRACH configuration period associated with the association period, and an integer value associated with the association period.

In this way, the scaling factor may be used to extend the periodicity of synchronization signal block to PRACH resource mapping pattern through signaling of a single value (i.e., the scaling factor), thereby reducing signaling overhead while still allowing for differently configured backhaul PRACH resources.

As further shown by reference number <NUM>, the new base station may determine the time offset of the backhaul PRACH resources. For example, the new base station may determine the time offset based at least in part on receiving the information that identifies the time offset from the target base station. In some aspects, the time offset may be in a range from zero to the periodicity of the backhaul PRACH resources. In some aspects, the time offset can be configured by the target base station or another wireless communication device associated with the IAB network, as described above. In some aspects, the time offset may be identified in terms of a number of radio frames, a number of slots, a number of subframes, a number of symbols, and/or the like. For example, the time offset may include a subframe level offset, such as a subframe level offset in a range from <NUM> to <NUM>. As another example, the time offset may include a slot level offset, such as a slot level offset in a range from <NUM> to <NUM> (e.g., when slot indexing is defined in terms of <NUM> numerology), or a range from <NUM> to <NUM> (e.g., when slot indexing is defined in terms of <NUM> numerology). In some aspects, the time offset is used to time division multiplex random access channel (RACH) resources across adjacent hops of a backhaul network.

In some aspects, the time offset may be different from an time offset that is identified based at least in part on a PRACH configuration index. For example, the new base station may determine a PRACH configuration index based at least in part on information carried in a system information block (e.g., SIB2) received by the new base station, as described above. Here, the time offset determined by the new base station (e.g., based on being signaled by the target base station) may be different from an time offset identified based at least in part on the PRACH configuration index (e.g., an time offset identified based at least in part on the PRACH configuration index table). In some aspects, the time offset may override the time offset that is identified based at least in part on the PRACH configuration index.

As shown by reference number <NUM>, the new base station may identify a set of backhaul PRACH resources based at least in part on the periodicity of the backhaul PRACH resources and/or based at least in part on the time offset. For example, the new base station may, based at least in part on the periodicity and the time offset, identify a radio frame location of a particular set of backhaul PRACH resources that, according to the mapping pattern, correspond to a particular synchronization signal block. As shown by reference number <NUM>, the new base station may then transmit a RACH transmission (e.g., MSG1) using the set of identified backhaul PRACH resources.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UEF entity, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a UEF entity (e.g., base station <NUM> with UEF, UE <NUM>) determines, based at least in part on a scaling factor, a periodicity of a backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is extended as compared to a periodicity of access PRACH resources.

As shown in <FIG>, in some aspects, process <NUM> may include identifying a scaling factor associated with determining a periodicity of backhaul physical random access channel (PRACH) resources (block <NUM>). For example, the UEF entity (e.g., using transmit processor <NUM>/<NUM>, controller/processor <NUM>/<NUM>, and/or the like), may identify a scaling factor associated with determining a periodicity of backhaul PRACH resources, as described above.

As shown in <FIG>, in some aspects, process <NUM> may include determining, based at least in part on the scaling factor, the periodicity of the backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is extended as compared to a periodicity of access PRACH resources (block <NUM>). For example, the UEF entity (e.g., using transmit processor <NUM>/<NUM>, controller/processor <NUM>/<NUM>, and/or the like), may determine, based at least in part on the scaling factor, the periodicity of the backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is extended as compared to a periodicity of access PRACH resources, as described above.

In a first aspect, the periodicity of the backhaul PRACH resources is associated with identifying a radio frame location of a set of backhaul PRACH resources.

In a second aspect, alone or in combination with the first aspect, the periodicity of the backhaul PRACH resources is determined based at least in part on the scaling factor and a PRACH configuration index.

In a third aspect, alone or in combination with one or more of the first and second aspects, the periodicity of the backhaul PRACH resources is determined based at least in part on multiplying the scaling factor and a periodicity of PRACH resources associated with the PRACH configuration index.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the PRACH resources associated with the PRACH configuration index are applicable for PRACH transmission in an access network.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, a range of the scaling factor is based at least in part on the periodicity of the PRACH resources associated with the PRACH configuration index.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, an association period, associated with mapping synchronization signal blocks to PRACH resources, is determined based at least in part on the scaling factor.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the association period is determined such that a pattern between PRACH occasions and synchronization signal blocks repeats at an amount of time that is equal to or less than a product of a PRACH configuration period and the scaling factor.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, an association pattern period, associated with mapping synchronization signal blocks to PRACH resources, is determined based at least in part on the scaling factor.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the association pattern period is determined based at least in part on the scaling factor, a PRACH configuration period associated with an association period, and an integer value associated with the association period.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the association pattern period is determined such that a pattern between PRACH occasions and synchronization signal blocks repeats at an amount of time that is equal to or less than a product of a fixed time value and the scaling factor.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the fixed time value is <NUM> milliseconds.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the scaling factor is signaled to the UEF entity via at least one of: remaining minimum system information; other system information; downlink control information; a medium access control (MAC) control element; radio resource control signaling; or a handover command.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the scaling factor is used in association with orthogonalizing RACH occasions across adjacent hops of a backhaul network.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by an access node functionality (ANF) entity, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where an ANF entity (e.g., base station <NUM> with ANF) signals a scaling factor, associated with determining a periodicity of a backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is to be extended as compared to a periodicity of access PRACH resources.

As shown in <FIG>, in some aspects, process <NUM> identifying a scaling factor to be used by a user equipment functionality (UEF) entity in association with determining a periodicity of backhaul physical random access channel (PRACH) resources (block <NUM>). For example, the ANF entity (e.g., using controller/processor <NUM>, and/or the like), may identify a scaling factor to be used by a UEF entity (e.g., a base station <NUM> with UEF) in association with determining a periodicity of backhaul PRACH resources, as described above. In some aspects, the periodicity of the backhaul PRACH resources is to be extended as compared to a periodicity of access PRACH resources.

As further shown in <FIG>, in some aspects, process <NUM> may include signaling the scaling factor to the UEF entity (block <NUM>). For example, the ANF entity (e.g., using transmit processor <NUM>, controller/processor <NUM>, and/or the like) may signal the scaling factor to the UEF entity, as described above.

In a second aspect, alone or in combination with the first aspect, the periodicity of the backhaul PRACH resources is to be determined based at least in part on the scaling factor and a PRACH configuration index.

In a third aspect, alone or in combination with one or more of the first and second aspects, the periodicity of the backhaul PRACH resources is to be determined based at least in part on multiplying the scaling factor and a periodicity of PRACH resources associated with the PRACH configuration index.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, an association pattern period, associated with mapping synchronization signal blocks to PRACH resources, is to be determined based at least in part on the scaling factor.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the association pattern period is to be determined based at least in part on the scaling factor, a PRACH configuration period associated with an association period, and an integer value associated with the association period.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the association pattern period is to be determined such that a pattern between PRACH occasions and synchronization signal blocks repeats at an amount of time that is equal to or less than a product of a fixed time value and the scaling factor.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by an ANF entity, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a wireless communication device (e.g., base station <NUM> with ANF) configures a time offset of backhaul PRACH resources, and transmits information that identifies the time offset.

As shown in <FIG>, in some aspects, process <NUM> may include configuring a time offset of backhaul PRACH resources (block <NUM>). For example, the wireless communication device (e.g., using controller/processor <NUM>, and/or the like), may configure a time offset of backhaul PRACH resources, as described above.

As shown in <FIG>, in some aspects, process <NUM> may include transmitting information that identifies the time offset (block <NUM>). For example, the wireless communication device (e.g., using antenna <NUM>, transmit processor <NUM>, controller/processor <NUM>, and/or the like), may transmit information that identifies the time offset, as described above. In some aspects, the time offset may be different from a time offset that is identified based at least in part on a PRACH configuration index.

In a first aspect, the time offset includes a subframe level offset.

In a second aspect, alone or in combination with the first aspect, the subframe level offset is in a range from <NUM> to <NUM>.

In a third aspect, alone or in combination with one or more of the first and second aspects, the time offset includes a slot level offset.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the slot level offset is in a range from <NUM> to <NUM>.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the slot indexing is defined in terms of <NUM> kilohertz (kHz) numerology.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the slot level offset is in a range from <NUM> to <NUM>.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the slot indexing is defined in terms of <NUM> kilohertz (kHz) numerology.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the time offset is used to time division multiplex random access channel (RACH) resources across adjacent hops of a backhaul network.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the time offset is signaled via at least one of: remaining minimum system information; other system information; downlink control information; a medium access control (MAC) control element; radio resource control signaling; or a handover command.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the time offset is used in association with orthogonalizing RACH occasions across adjacent hops of a backhaul network.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the time offset is in a range from zero to a periodicity of the backhaul PRACH resources.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the time offset overrides the time offset that is identified based at least in part on the PRACH configuration index.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UEF entity, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a UEF entity (e.g., base station <NUM> with UEF, UE <NUM>) identifies a set of backhaul PRACH resources based at least in part on a time offset and transmits a RACH transmission using the identified set of PRACH resources.

As shown in <FIG>, in some aspects, process <NUM> may include receiving information that identifies a time offset associated with backhaul PRACH resources (block <NUM>). For example, the UEF entity (e.g., using antenna <NUM>/<NUM>, receive processor <NUM>/<NUM>, controller/processor <NUM>/<NUM>, and/or the like), receiving information that identifies a time offset associated with backhaul PRACH resources, as described above. In some aspects, the time offset may be different from a time offset that is identified based at least in part on a PRACH configuration index.

As shown in <FIG>, in some aspects, process <NUM> may include identifying a set of backhaul PRACH resources based at least in part on the time offset (block <NUM>). For example, the UEF entity (e.g., using controller/processor <NUM>/<NUM>, and/or the like), may identify a set of backhaul PRACH resources based at least in part on the time offset, as described above.

As shown in <FIG>, in some aspects, process <NUM> may include transmitting a RACH transmission using the identified set of back backhaul PRACH resources (block <NUM>). For example, the UEF entity (e.g., using antenna <NUM>/<NUM>, transmit processor <NUM>/<NUM>, controller/processor <NUM>/<NUM>, and/or the like), may transmit a RACH transmission using the identified set of back backhaul PRACH resources. , as described above.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the time offset is signaled to the UEF entity via at least one of: remaining minimum system information; other system information; downlink control information; a medium access control (MAC) control element; radio resource control signaling; or a handover command.

Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of possible aspects. Although each dependent claim listed below may directly depend on only one claim, the disclosure of possible aspects includes each dependent claim in combination with every other claim in the claim set.

Claim 1:
A method (<NUM>) of wireless communication performed by an access node functionality, ANF, entity, comprising:
configuring (<NUM>) a first time offset of backhaul physical random access channel, PRACH, resources;
configuring a scaling factor associated with a periodicity of the backhaul PRACH resources, wherein the periodicity of the backhaul PRACH resources is to be determined based at least in part on multiplying the scaling factor and a periodicity of PRACH resources associated with a PRACH configuration index; and
transmitting (<NUM>) information (<NUM>) that identifies the first time offset and the scaling factor, wherein the first time offset is different from a second time offset that is identified based at least in part on the PRACH configuration index.