Apparatus and method for communication using buffer status reports

Abstract

Methods and apparatuses for communicating in an integrated access and backhaul (IAB) system using a buffer status report (BSR) are disclosed. The apparatus includes: a receiver that receives a BSR indicating a desire to receive data; a processor that calculates a first type of buffer size based on the received BSR indicating a desire to receive data and / or calculates a second type of buffer size based on data currently stored in a buffer; and a transmitter that transmits a buffer status including the first type of buffer size and / or the second type of buffer size.

Description

Technical Field

[0001] The subject matter disclosed herein generally relates to wireless communication, and more particularly, to apparatuses and methods for communicating in an integrated access and backhaul (IAB) system using buffer status reports (BSRs). Background Art

[0002] The following acronyms and abbreviations are defined herein, and at least some of them are referenced in the following description.

[0003] 3rd Generation Partnership Project (“3GPP”), New Radio (“NR”), evolved Node B (“eNB”), 5G Node B (“gNB”), Downlink (“DL”), Uplink (“UL”), Long Term Evolution (“LTE”), LTE-Advanced (“LTE-A”), Evolved UMTS Terrestrial Radio Access Network (“E-UTRAN”), Acknowledgement (“ACK”), Negative Acknowledgement (“NACK”), Hybrid Automatic Repeat reQuest (“HARQ”), Hybrid Automatic Repeat reQuest - Acknowledgement (“HARQ-ACK”), Hybrid Automatic Repeat reQuest - Negative Acknowledgement (“HARQ-NACK”), Machine Type Communication (“MTC”), Enhanced MTC (“eMTC”), NarrowBand Internet of Things (“NB-IoT”), Internet of Things (“IoT”), Physical Downlink Control Channel (“PDCCH”), MTC Physical Downlink Control Channel (“MPDCCH”), Narrowband Physical Downlink Control Channel (“NPDCCH”), Physical Downlink Shared Channel (“PDSCH”), Time Division Duplexing (“TDD”), Frequency Division Multiplexing (“FDM”), Time Division Multiplexing (“TDM”), Code Division Multiplexing (“CDM”), User Equipment / Device (Remote Device) (“UE”), Network Equipment (“NE”), Discontinuous Reception (“DRX”), Low Power Wide Area (“LPWA”), Paging Occasion (“PO”), System Information Block (“SIB”), Bandwidth Reduction Low Complexity / Coverage Enhancement (“BL / CE”), Identification (“ID”), Non-Access Stratum (“NAS”), Preconfigured Uplink Resource (“PUR”), Common Search Space (“CSS”), UE-Specific Search Space (“USS”), Single Carrier Frequency Division Multiple Access (“SC-FDMA”), Transport Block Size (“TBS”), Modulation and Coding Scheme (“MCS”), Downlink Control Indicator (“DCI”), Random Access Channel (“RACH”), Physical Random Access Channel (“PRACH”), Medium Access Control (“MAC”), Downlink Shared Channel (“DL-SCH”), Uplink Shared Channel (“UL-SCH”), Random Access Response (“RAR”), Radio Network Temporary Identifier (“RNTI”), Random Access Radio Network Temporary Identifier (“RA-RNTI”), Single Frequency Network (“SFN”), Buffer Status Report (“BSR”), Integrated Access and Backhaul (“IAB”), Millimeter Wave (“mmWave”), Mobile Terminal (“MT”) and Distributed Unit (“DU”), Central Unit (“CU”), gNB Central Unit (“gNB-CU”), gNB Distributed Unit (“gNB-DU”), gNB Central Unit Control Plane (“gNB-CU-CP”), gNB Central Unit User Plane (“gNB-CU-UP”), Radio Resource Control (“RRC”)Service Data Adaptation Protocol (“SDAP”) and Packet Data Convergence Protocol (“PDCP”), Radio Link Control (“RLC”), Physical Layer (“PHY”), Next Generation Radio Access Network (“NG-RAN”), Scheduling Request (“SR”), End-to-End (“E2E”), MAC Control Element (“MAC CE”), Logical Channel (“LCH”), Logical Channel ID (“LCID”), Protocol Data Unit (“PDU”), Logical Channel Group (“LCG”), Physical Uplink Shared Channel (“PUSCH”).

[0004] In wireless communications such as those of the 3rd Generation Partnership Project (“3GPP”) mobile networks, a wireless mobile network can provide seamless wireless communication services to wireless communication terminals with mobility. The wireless mobile network can be formed by multiple base stations. Each base station can operate a cell. The base station can communicate wirelessly with the wireless communication terminals placed within the corresponding cell.

[0005] The radio technologies in cellular communications have developed rapidly. The traffic volume in cellular networks has experienced huge growth and expansion. Therefore, the future network development is driven by the need to provide and consider massive connectivity and capacity, extended throughput and capacity, and ultra-low latency. The 5th Generation (5G) access network, which can also be referred to as the New Radio (NR) access network, is currently under development and is expected to handle a very wide range of use cases and requirements.

[0006] With the increasing densification of the network, it has become extremely difficult to provide traditional fiber optic backhaul access for each cell base station, which is especially true for small cell base stations. The increasing maturity of millimeter wave (mmWave) communications has opened up the possibility of providing high-speed wireless backhaul to such cell stations. Since mmWave is also applicable to the access link, the 3rd Generation Partnership Project (3GPP) is envisioning an Integrated Access and Backhaul (IAB) architecture for the 5th Generation (5G) cellular network, where the same infrastructure and spectrum resources will be used for access and backhaul. Summary of the Invention

[0007] Apparatuses and methods for communicating with buffer status reports are disclosed.

[0008] According to a first aspect, there is provided an apparatus comprising: a receiver that receives a buffer status report (BSR) indicating a desire to receive data; a processor that calculates a first type of buffer size based on the received BSR indicating a desire to receive data and / or calculates a second type of buffer size based on the data currently stored in the buffer; and a transmitter that transmits a buffer status including the first type of buffer size and / or the second type of buffer size.

[0009] Optionally, the receiver receives multiple BSRs from multiple remote devices.

[0010] Optionally, the received BSRs include multiple logical channel groups for receiving data and buffer sizes for each of the logical channel groups; the first type of buffer size includes an early buffer size that indicates the amount of data expected to be received in the multiple logical channel groups; and the buffer status to be reported is a combined buffer status and further includes a first buffer status that includes information on the first type of buffer size; and a second buffer status that includes a second type of buffer size described as a short BSR format or a long BSR format or a long truncated BSR format.

[0011] Optionally, the second buffer status includes a second type of buffer size described as a short BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status added to the end of the second buffer status.

[0012] Optionally, the second buffer status includes a buffer size described as a long BSR format or a long truncated BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status added to the end of the long BSR format or the long truncated BSR format.

[0013] Optionally, the first type of buffer size includes a total early buffer size that indicates the amount of data expected to be received from the multiple remote devices until the media access control protocol data unit (MAC PDU) component.

[0014] Optionally, the receiver receives multiple BSRs from a single remote device; and the first type of buffer size is calculated based on the last received BSR.

[0015] Optionally, the buffer status to be reported is assigned a logical channel ID (LCID) that is different from the LCID of the short BSR, long BSR, or truncated BSR.

[0016] Optionally, the received BSRs include multiple logical channel groups for receiving data and buffer sizes for each of the logical channel groups; and the first type of buffer size is organized according to priority information.

[0017] Optionally, the information of the logical channel group is priority information.

[0018] Optionally, the received BSR includes a first received BSR from a first remote device and a second received BSR from a second remote device; the first received BSR includes multiple instances of buffer sizes with priorities; the second received BSR includes multiple instances of buffer sizes with the same priority; and the buffer size values with the same priority from the first received BSR and the second received BSR are accumulated to form the buffer size for the priority.

[0019] Optionally, the received BSR includes a first received BSR from a first remote device and a second received BSR from a second remote device; the buffer size with a priority corresponds to a first type of buffer size; the buffer sizes with the same priority correspond to a second type of buffer size; and the buffer size values with the same priority from the first type of buffer size and the second type of buffer size are accumulated to form the buffer size for the priority.

[0020] Optionally, when the available uplink resources for transmitting the buffer status are limited, the first type of buffer size is included in the buffer status report with a higher priority than the second type of buffer size.

[0021] Optionally, when the available uplink resources for transmitting the buffer status are limited, the second type of buffer size is included in the buffer status report with a higher priority than the first type of buffer size.

[0022] Optionally, when the available uplink resources for transmitting the buffer status are limited, the information of the buffer sizes with a higher priority from the first type of buffer size and the second type of buffer size is included in the buffer status report.

[0023] Optionally, the received BSR includes multiple logical channel groups for receiving data and a buffer size for each of the logical channel groups; the first type of buffer size includes an early buffer size that indicates the amount of data expected to be received in the multiple logical channel groups.

[0024] Optionally, the received BSR includes multiple logical channel groups for receiving data and a buffer size for each of the logical channel groups; the first type of buffer size is organized according to priority information.

[0025] Optionally, the information of the logical channel groups is used to identify the priority information.

[0026] Optionally, the buffer status to be reported further includes the information of the logical channel groups for transmitting data.

[0027] According to a second aspect, there is provided an apparatus, the apparatus comprising: a receiver that receives a plurality of BSRs from a plurality of remote devices; and a transmitter that transmits an indication of a buffer status for which data is expected to be received; wherein, when it is determined that no uplink resources are available, the transmitter transmits a scheduling request (SR).

[0028] Optionally, the BSR includes a plurality of logical channel groups; a priority value can be obtained from the identification of the logical channel groups; and the transmission of the SR is selected based on the highest priority value of the logical channels included in the plurality of logical channel groups.

[0029] According to a third aspect, there is provided a method, the method comprising: receiving, by a receiver, a buffer status report (BSR) indicating a buffer status for which data is expected to be received; calculating, by a processor, a first type of buffer size based on the received BSR indicating a buffer status for which data is expected to be received and / or a second type of buffer size based on data currently stored in the buffer; and transmitting, by a transmitter, a buffer status including the first type of buffer size and / or the second type of buffer size.

[0030] Optionally, the receiver receives a plurality of BSRs from a plurality of remote devices.

[0031] Optionally, the received BSR includes a plurality of logical channel groups for receiving data and a buffer size for each of the logical channel groups; the first type of buffer size includes an early buffer size that indicates the amount of data expected to be received in the plurality of logical channel groups; and the buffer status to be reported is a combined buffer status and further includes a first buffer status that includes information on the first type of buffer size; and a second buffer status that includes the second type of buffer size described as a short BSR format or a long BSR format or a long truncated BSR format.

[0032] Optionally, the second buffer status includes the second type of buffer size described as a short BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status added to the end of the second buffer status.

[0033] Optionally, the second buffer status includes the buffer size described as a long BSR format or a long truncated BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status added to the end of the long BSR format or the long truncated BSR format.

[0034] Optionally, the buffer size of the first type includes a total early buffer size that indicates the amount of data expected to be received from the plurality of remote devices up to the media access control protocol data unit (MAC PDU) component.

[0035] Optionally, the receiver receives multiple BSRs from a single remote device; and the buffer size of the first type is calculated based on the last received BSR.

[0036] Optionally, the buffer status to be reported is assigned a logical channel ID (LCID) that is different from the LCID of the short BSR, long BSR, or truncated BSR.

[0037] Optionally, the received BSR includes multiple logical channel groups for receiving data and a buffer size for each of the logical channel groups; and the buffer size of the first type is organized according to priority information.

[0038] Optionally, the information of the logical channel group is priority information.

[0039] Optionally, the received BSR includes a first received BSR from a first remote device and a second received BSR from a second remote device; the first received BSR includes multiple instances of buffer sizes with priorities; the second received BSR includes multiple instances of buffer sizes with the same priority; and the buffer size values with the same priority from the first received BSR and the second received BSR are accumulated to form the buffer size of the priority.

[0040] Optionally, the received BSR includes a first received BSR from a first remote device and a second received BSR from a second remote device; the buffer size with priority corresponds to the buffer size of the first type; the buffer size with the same priority corresponds to the buffer size of the second type; and the buffer size values with the same priority from the buffer size of the first type and the buffer size of the second type are accumulated to form the buffer size of the priority.

[0041] Optionally, when the available uplink resources for transmitting the buffer status are limited, the buffer size of the first type is included in the buffer status report with a higher priority than the buffer size of the second type.

[0042] Optionally, when the available uplink resources for transmitting the buffer status are limited, the buffer size of the second type is included in the buffer status report with a higher priority than the buffer size of the first type.

[0043] Optionally, when the available uplink resources for transmitting buffer status are limited, information on the buffer size with higher priority from the buffer sizes of the first type and the second type is included in the buffer status report.

[0044] Optionally, the received BSR includes a plurality of logical channel groups for receiving data and a buffer size for each of the logical channel groups; the buffer size of the first type includes an early buffer size that indicates the amount of data expected to be received in the plurality of logical channel groups.

[0045] Optionally, the received BSR includes a plurality of logical channel groups for receiving data and a buffer size for each of the logical channel groups; the buffer size of the first type is organized according to priority information.

[0046] Optionally, the information of the logical channel group is used to identify the priority information.

[0047] Optionally, the buffer status to be reported further includes information on the logical channel group for transmitting data.

[0048] According to a fourth aspect, there is provided a method, which includes: receiving, by a receiver, a plurality of BSRs from a plurality of remote devices; transmitting, by a transmitter, an indication of the buffer status for expected received data; and transmitting, by the transmitter, a scheduling request (SR) when it is determined that no uplink resources are available.

[0049] Optionally, the BSR includes a plurality of logical channel groups; a priority value can be obtained from the identification of the logical channel group; and the transmission of the SR is selected based on the highest priority value of the logical channels included in the plurality of logical channel groups. Description of the Drawings

[0050] A more specific description of the embodiments will be rendered with reference to the specific embodiments shown in the drawings. Considering that these drawings only depict some embodiments and are not considered to limit the scope, the embodiments will be described and illustrated with additional specificity and detail by using the drawings, in which:

[0051] Figure 1A is a schematic diagram illustrating a wireless communication system;

[0052] Figure 1B is a schematic block diagram illustrating the implant architecture of a wireless communication system;

[0053] Figure 2 is a schematic block diagram illustrating the components of a user equipment according to an embodiment;

[0054] Figure 3is a schematic block diagram illustrating components of a network device according to an embodiment;

[0055] Figure 4A is a schematic diagram illustrating uplink processing in an IAB network;

[0056] Figure 4B is a schematic diagram illustrating a short BSR and a short truncated BSR MAC CE;

[0057] Figure 4C is a schematic diagram illustrating a long BSR and a long truncated BSR MAC CE;

[0058] Figure 5A is a schematic diagram illustrating a combined BSR with a short BSR;

[0059] Figure 5B is a schematic diagram illustrating a combined BSR with a long BSR;

[0060] Figure 5C is a schematic diagram illustrating a combined BSR with a short BSR without an LCG ID;

[0061] Figure 5D is a schematic diagram illustrating a combined BSR with a short BSR including an LCG ID;

[0062] Figure 5E is a schematic diagram illustrating a combined BSR with a long BSR without an LCG ID;

[0063] Figure 5F is a schematic diagram illustrating a combined BSR with a long BSR including an LCG ID;

[0064] Figure 6A is a schematic diagram illustrating a short early BSR;

[0065] Figure 6B is a schematic diagram illustrating a long (truncated) early BSR;

[0066] Figure 7 is a flowchart illustrating steps for communicating using processing of a BSR;

[0067] Figure 8 is a flowchart illustrating steps for communicating using processing of an SR and a BSR. Detailed Description

[0068] As will be appreciated by those skilled in the art, aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects.

[0069] For example, the disclosed embodiments may be implemented as hardware circuitry that includes custom very large scale integration (“VLSI”) circuits or gate arrays, such as logic chips, off-the-shelf semiconductors, or other discrete components. The disclosed embodiments may also be implemented in programmable hardware devices, such as field programmable gate arrays, programmable array logic, programmable logic devices, etc. As another example, the disclosed embodiments may include one or more physical or logical blocks of executable code, e.g., these blocks may be organized as objects, programs, or functions.

[0070] In addition, one or more embodiments may take the form of a program product that is embodied in one or more computer-readable storage devices that store machine-readable code, computer-readable code, and / or program code, hereinafter referred to as “code”. The storage device may be tangible, non-transitory, and / or non-transmissive. The storage device may not embody a signal. In certain embodiments, the storage device merely takes the form of a signal for accessing the code.

[0071] Any combination of one or more computer-readable media may be utilized. The computer-readable media may be a computer-readable storage medium. The computer-readable storage medium may be a storage device that stores the code. For example, the storage device may be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0072] A non-exhaustive list of more specific examples of storage devices may include the following: an electrical connection having one or more wires, a portable computer floppy disk, a hard disk, a random access memory (“RAM”), a read-only memory (“ROM”), an erasable programmable read-only memory (“EPROM”) or flash memory, a portable compact disc read-only memory (“CD-ROM”), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this disclosure, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0073] Throughout this specification, references to "one embodiment", "an embodiment", "an example", "some embodiments" or similar language mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment", "in an embodiment", "in some embodiments" and similar language throughout this specification are not necessarily all referring to the same embodiment, but rather to "one or more embodiments". These may or may not include all of the disclosed embodiments. Unless otherwise expressly specified, the terms "comprising", "including", "having" and their variants mean "including but not limited to".

[0074] Unless otherwise expressly specified, an enumerated listing of items does not imply that any or all of the items are mutually exclusive. Unless otherwise expressly specified, the terms "a", "an" and "the" also mean "one or more".

[0075] Throughout this disclosure, unless otherwise expressly specified, the terms "first", "second", "third", etc. are used only as a nomenclature for referring to related devices, components, program steps, etc., and do not imply any spatial or temporal order. For example, "a first device" and "a second device" may refer to two separate forms of devices or two components or parts of the same device. Similarly, a "first step" of a method or process may be performed after or simultaneously with a "second step".

[0076] Furthermore, the described features, structures, or characteristics of the embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of the embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific details or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the embodiments.

[0077] Aspects of various embodiments are described below with reference to schematic flowcharts and / or schematic block diagrams according to methods, apparatuses, systems, and program products. It will be understood that each block of the schematic flowcharts and / or schematic block diagrams, and combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by code. Such code can be provided to a processor of a general purpose computer, a special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing apparatus create a means for implementing the functions / actions specified in the schematic flowchart and / or schematic block diagram.

[0078] The code can also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices to operate in a specific manner, such that the instructions stored in the storage device produce an article of manufacture that includes instructions for implementing the functions / actions specified in the illustrative flowchart(s) and / or illustrative block diagram(s).

[0079] The code can also be loaded onto a computer, other programmable data processing apparatus, or other devices, causing a series of operational steps to be performed on the computer, other programmable apparatus, or other devices to produce a computer-implemented process, such that the code executed on the computer or other programmable apparatus provides a process for implementing the functions / actions specified in the illustrative flowchart(s) and / or illustrative block diagram(s).

[0080] The illustrative flowchart(s) and / or illustrative block diagram(s) in the figures illustrate the architecture, functionality, and operation of possible implementations of different apparatuses, systems, methods, and program products according to various embodiments. In this regard, each block in the illustrative flowchart(s) and / or illustrative block diagram(s) can represent a module, segment, or portion of code, including one or more executable instructions for implementing the specified logical function. However, those skilled in the relevant art will recognize that the flowchart(s) do not necessarily have to be practiced in the order shown, and can be practiced with one or more of the specific steps missing or with other steps not shown.

[0081] It should also be noted that in some alternative implementations, the functions noted in the identified blocks may occur out of the order noted in the figures. For example, depending on the functionality involved, two blocks shown in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order. Other steps and methods can be envisioned that are equivalent in function, logic, or effect to one or more blocks or portions thereof shown in the figures.

[0082] The description of the elements in each figure can refer to the elements of the previous figure. In all the figures, the same numerals refer to the same elements, including alternative embodiments of the same elements.

[0083] Figure 1A is a schematic diagram illustrating a wireless communication system. It depicts an embodiment of a wireless communication system 100 of an IAB network. In one embodiment, the wireless communication system 100 includes user equipment (UE) 102 and network equipment (NE) 104 / 106. Although a specific number of UEs 102 and NEs 104 / 106 are depicted in FIG. 1, those skilled in the art will recognize that any number of UEs 102 and NEs 104 / 106 can be included in the wireless communication system 100.

[0084] In one embodiment, the UE 102 may include computing devices such as desktop computers, laptop computers, personal digital assistants ("PDAs"), tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet), set-top boxes, gaming consoles, security systems (including security cameras), in-vehicle computers, network devices (e.g., routers, switches, modems), etc. In some embodiments, the UE 102 includes wearable devices such as smart watches, fitness bands, optical head-mounted displays, etc. Additionally, the UE 102 may be referred to as a remote unit, user unit, mobile device, mobile station, user, terminal, mobile terminal, fixed terminal, user station, user terminal, device, or other terms used in the art. The UE 102 may communicate directly with one or more NEs 104 / 106 via UL communication signals.

[0085] Network devices may be distributed over a geographical area. In this exemplary IAB network, the network devices 104 / 106 include a plurality of IAB nodes 104 and a donor node or IAB donor 106. In certain embodiments, the network devices 104 / 106 may also be referred to as access points, access terminals, pedestals, base stations, Node B, eNB, gNB, master Node B, relay nodes, devices, or any other terms used in the art. Throughout this specification, references to base stations may refer to any of the above types of network devices 104 / 106, such as eNG and gNB. The network devices 104 / 106 are typically part of a radio access network that includes one or more controllers communicatively coupled to one or more respective network devices 104 / 106. The radio access network is typically communicatively coupled to one or more core networks, which may be coupled to other networks such as the Internet and the public switched telephone network and other networks. These and other elements of the radio access network and the core network are not shown, but are generally well known to those of ordinary skill in the art.

[0086] In one implementation, the wireless communication system 100 complies with 3GPP 5G New Radio (NR). In some implementations, the wireless communication system 100 complies with 3GPP protocols, where the NEs 104 / 106 use an OFDM modulation scheme for transmission on the DL and the UE 102 uses an SC-FDMA scheme or an OFDM scheme for transmission on the UL. However, more generally, the wireless communication system 100 may implement some other open or proprietary communication protocols, such as WiMAX, among other protocols. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

[0087] The network devices 104 / 106 can serve multiple UEs 102 within the serving area of, for example, a cell (or cell sector) or multiple cells via a wireless communication link. The network devices 104 / 106 transmit DL communication signals in the time domain, frequency domain, and / or spatial domain to serve the UEs 102.

[0088] The IAB network shown in FIG. 1 provides more range extension with multi-hop backhaul than single-hop. For example, UE3 can be connected to a donor node relayed by IAB node 1, IAB node 2, and IAB node 3. This is particularly beneficial for frequencies above 6 GHz due to their limited range. The multi-hop backhaul further enables the backhaul to bypass obstacles, such as buildings in an urban environment, for a clutter-free deployment. The IAB node 104 can be stationary or carried by a moving object.

[0089] Wireless backhaul links can be vulnerable to blockage, for example, due to moving objects such as vehicles, due to seasonal changes such as leaves, or due to infrastructure changes such as new buildings. This drawback also applies to physically stationary IAB nodes. For example, if the backhaul link with IAB node 1 is blocked by a moving object, IAB node 2 can switch its connection from IAB node 1 to IAB node 0.

[0090] Figure 1B is a schematic block diagram illustrating the implementation architecture of a wireless communication system. It shows a reference diagram of an IAB node in stand-alone mode, which includes an IAB donor 106 and multiple IAB nodes 104. The IAB donor 106 can be regarded as a single logical node that includes a set of functions, such as a gNB distributed unit (gNB-DU), a gNB central unit control plane (gNB-CU-CP), a gNB central unit user plane (gNB-CU-UP), and potentially other functions. In a deployment, the IAB donor can be split according to these functions, all of which can be configured or unconfigured, as allowed by the 3GPP next-generation radio access network (NG-RAN) architecture.

[0091] Each IAB node 104 can include a mobile terminal (MT) and a distributed unit (DU). The MT function has been defined as a component of a mobile device or user equipment (UE). In this example, the MT can be referred to as a function residing on the IAB node 104 that terminates the radio interface layer of the backhaul Uu interface to the IAB donor 106 or other IAB nodes 104. The Uu interface, also known as the air interface, is the interface between a 5G UE and the 5G-RAN.

[0092] The IAB donor 106, which may also be referred to as a gNB or a base station, may include a gNB central unit (gNB-CU) or one or more gNB distributed units (gNB-DUs). The gNB-CU and the gNB-DU are connected via an F1 interface. The gNB-CU is a logical node that hosts the RRC, SDAP, and PDCP protocols of the gNB. The gNB-DU is a logical node that hosts the RLC, MAC, and PHY layers of the gNB. A cell can be supported by only one gNB-DU or IAB node DU. The IAB donor 106 may be communicatively coupled to a core network or a next generation core (NGC), which in turn may be coupled to other networks.

[0093] In Figure 1A the IAB network shown, the IAB donor 106 is typically stationary, while both the IAB node 104 and the UE 102 can be either stationary or mobile. Therefore, both the UE 102 and the IAB node 104 can be referred to as remote devices.

[0094] An IAB node 104 in a communication chain is referred to as a parent IAB node or a child IAB node based on its relative position to another IAB node. For example, IAB node 2 is the parent IAB node relative to IAB node 3, and this IAB node 2 is also the child IAB node relative to IAB node 1. Each IAB node can act as a user equipment of its parent IAB node and can also act as a base station of its child IAB node.

[0095] Figure 2 is a schematic block diagram illustrating components of a UE according to an embodiment. The UE 200 may include a processor 202, a memory 204, an input device 206, a display 208, and a transceiver 210. In some embodiments, the input device 206 and the display 208 are combined into a single device, such as a touch screen. In certain embodiments, the UE 200 may not include any input device 206 and / or display 208. In various embodiments, the UE 200 may include one or more processors 202 and may not include the input device 206 and / or display 208.

[0096] In one embodiment, the processor 202 may include any known controller capable of executing computer-readable instructions and / or capable of performing logical operations. For example, the processor 202 may be a microcontroller, a microprocessor, a central processing unit (“CPU”), a graphics processing unit (“GPU”), an auxiliary processing unit, a field-programmable gate array (“FPGA”), or a similar programmable controller. In some embodiments, the processor 202 executes instructions stored in the memory 204 to perform the methods and routines described herein. The processor 202 is communicatively coupled to the memory 204 and the transceiver 210.

[0097] In one embodiment, the memory 204 is a computer-readable storage medium. In some embodiments, the memory 204 includes volatile computer storage media. For example, the memory 204 may include RAM, including dynamic RAM ("DRAM"), synchronous dynamic RAM ("SDRAM"), and / or static RAM ("SRAM"). In some embodiments, the memory 204 includes non-volatile computer storage media. For example, the memory 204 may include a hard disk drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory 204 includes both volatile and non-volatile computer storage media. In some embodiments, the memory 204 stores data related to trigger conditions for transmitting measurement reports to a network device. In some embodiments, the memory 204 also stores programs and related data.

[0098] In one embodiment, the input device 206 may include any known computer input device, including a touch panel, buttons, a keyboard, a stylus, a microphone, etc. In some embodiments, the input device 206 may be integrated with the display 208, for example, as a touch screen or a similar touch-sensitive display. In some embodiments, the input device 206 includes a touch screen such that text can be input using a virtual keyboard displayed on the touch screen and / or by handwriting on the touch screen. In some embodiments, the input device 206 includes two or more different devices, such as a keyboard and a touch panel.

[0099] In one embodiment, the display 208 may include any known electronic control display or display device. The display 208 may be designed to output visual, audio, and / or tactile signals. In some embodiments, the display 208 includes an electronic display capable of outputting visual data to a user. For example, the display 208 may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or a similar display device capable of outputting images, text, etc. to a user. As another non-limiting example, the display 208 may include a wearable display, such as a smart watch, smart glasses, a head-up display, etc. Further, the display 208 may be a component of a smart phone, a personal digital assistant, a television, a tablet computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, etc.

[0100] In some embodiments, the display 208 includes one or more speakers for generating sound. For example, the display 208 can generate an audible alert or notification (e.g., a beep or a chime). In some embodiments, the display 208 includes one or more haptic devices for generating vibration, movement, or other haptic feedback. In some embodiments, all or part of the display 208 can be integrated with the input device 206. For example, the input device 206 and the display 208 can form a touch screen or a similar touch-sensitive display. In other embodiments, the display 208 can be located near the input device 206.

[0101] In one embodiment, the transceiver 210 is configured to communicate wirelessly with a network device. In certain embodiments, the transceiver 210 includes a transmitter 212 and a receiver 214. The transmitter 212 is used to transmit UL communication signals to the network device, and the receiver 214 is used to receive DL communication signals from the network device. For example, the transmitter 212 can transmit a HARQ-ACK including feedback for one or more DL transmissions. As another example, the receiver 214 can receive various configurations / data from the network device.

[0102] The transmitter 212 and the receiver 214 can be any suitable type of transmitter and receiver. Although only one transmitter 212 and one receiver 214 are illustrated, the transceiver 210 can have any suitable number of transmitters 212 and receivers 214. For example, in some embodiments, the UE 200 includes multiple pairs of transmitters 212 and receivers 214 for communicating on multiple wireless networks and / or radio frequency bands, and each pair of transmitters 212 and receivers 214 is configured to communicate on a wireless network and / or radio frequency band different from other pairs of transmitters 212 and receivers 214.

[0103] Figure 3 is a schematic block diagram illustrating components of a network device according to one embodiment. The network device (NE) 300 can be an implementation of the IAB node 104 or the IAB donor 106. Logically, as Figure 1B shown, the IAB node 104 can include a mobile terminal (MT) and a distributed unit (DU); and the IAB donor 106 can include a gNB central unit (gNB-CU) and one or more gNB distributed units (gNB-DU).

[0104] The NE 300 may include a processor 302, a memory 304, an input device 306, a display 308, and a transceiver 310. As can be appreciated, in some embodiments, the processor 302, the memory 304, the input device 306, the display 308, and the transceiver 310 may be similar to the processor 202, the memory 204, the input device 206, the display 208, and the transceiver 210 of the UE 200, respectively.

[0105] In some embodiments, the processor 302 controls the transceiver 310 to transmit DL signals / data to the UE 200. The processor 302 may also control the transceiver 310 to receive UL signals / data from the UE 200. For example, the processor 302 may control the transceiver 310 to receive HARQ-ACK including feedback for one or more DL transmissions. In another example, the processor 302 may control the transceiver 310 to transmit DL signals for various configurations to the UE 200, as described above.

[0106] In one embodiment, the transceiver 310 is configured to communicate wirelessly with the UE 200. In certain embodiments, the transceiver 310 includes a transmitter 312 and a receiver 314. The transmitter 312 is used to transmit DL communication signals to the UE 200, and the receiver 314 is used to receive UL communication signals from the UE 200. For example, the receiver 314 may receive a HARQ-ACK codebook from the UE 200. As another example, the transmitter 312 may transmit various configurations / data of the NE 300.

[0107] The transceiver 310 may communicate with multiple UEs 200 simultaneously. For example, the transmitter 312 may transmit DL communication signals to the UE 200. As another example, the receiver 314 may receive UL communication signals from the UE 200 simultaneously. The transmitter 312 and the receiver 314 may be any suitable type of transmitter and receiver. Although only one transmitter 312 and one receiver 314 are illustrated, the transceiver 310 may have any suitable number of transmitters 312 and receivers 314. For example, the NE 300 may serve multiple cells and / or sectors, where the transceiver 310 includes a transmitter 312 and a receiver 314 for each cell or cell sector.

[0108] Figure 4AIt is a schematic diagram illustrating uplink processing in an IAB network. This shows the worst-case scenario where none of the intermediate nodes 104a and 104b have any UL resources allocated to them. In this case, the UE 102 must first send a scheduling request (SR) to the IAB node 104b or the IAB node 2, and then wait for a UL grant. When receiving the UL grant from the IAB node 2, the UE 102 is able to transmit a buffer status report (BSR) to the IAB node 104b, and then must wait for another UL grant. The data or protocol data unit (PDU) stored in the buffer can be transmitted only after receiving the second UL grant. The IAB node 104b then receives the data and must further relay it to the IAB node 104a and the IAB donor 106. Therefore, this entire process between the UE 102 and the IAB node 104b must be repeated between the IAB node 104b and the IAB node 104a, and again between the IAB node 104a and the IAB donor 106, thus resulting in a significant cumulative delay.

[0109] The increased latency due to multi-hop in the IAB network may have an adverse impact on the performance of both control plane procedures (such as handover and radio link recovery) and user plane data transmission. To achieve hop-agnostic performance in IAB scheduling, it is important to reduce the end-to-end (E2E) delay from the UE 102 to the IAB donor 106 and meet the latency requirements regardless of how many hops the UE 102 is away from the IAB donor 106.

[0110] In a multi-hop network, upstream data from a child node may suffer scheduling delays at the parent node and intermediate nodes. To some extent, this is different from a single-hop UE, where new data arrives at the UE buffer after transmitting the BSR. However, in a multi-hop network, due to the number of hops and the aggregated data volume at the IAB nodes, the delay may accumulate and a mitigation mechanism may be required.

[0111] Obviously, due to multiple consecutive uplink resource requests and allocation steps, this process may be significantly longer than the corresponding process in a single-hop network. The root cause of these delays is that the MT part of the IAB node 104 can request uplink resources for UL data transmission only after it actually receives the data to be transmitted.

[0112] MAC control elements (MAC CEs) are used for MAC layer control signaling between the NE 300 and the UE 200. Several types of MAC CEs are available, such as buffer status report MAC CE, C-RNTI MAC CE, UE contention resolution identity MAC CE, timing advance command MAC CE, DRX command MAC CE, etc.

[0113] The Buffer Status Report (BSR) MAC CE includes information on how much of the data accumulated in the UE's buffer has been transmitted from the UE 200 to the NE 300. Four different Logical Channel ID (LCID) values can be used to distinguish between short BSR, long BSR, short truncated BSR, and long truncated BSR.

[0114] The BSR MAC CE can be any of the following:

[0115] Short BSR format (fixed size),

[0116] Long BSR format (variable size),

[0117] Short truncated BSR format (fixed size) or

[0118] Long truncated BSR format (variable size).

[0119] The BSR format is identified by the MAC PDU sub-header with the LCID. The number of buffer size fields in the long BSR format and the long truncated BSR format can be zero. In one example, the fields in the BSR MAC CE are defined as follows:

[0120] LCG ID: The Logical Channel Group ID field identifies the logical channel group for which the buffer status is being reported. The length of the field is 3 bits;

[0121] LCGi: For the long BSR format, this field indicates the presence of a buffer size field for logical channel group i. The LCGi field set to '1' indicates that the buffer size field for logical channel group i is being reported. The LCGi field set to '0' indicates that the buffer size field for logical channel group i is not being reported. For the long truncated BSR format, this field indicates whether there is available data for logical channel group i. The LCGi field set to '1' indicates that there is available data for logical channel group i. The LCGi field set to '0' indicates that there is no available data for logical channel group i.

[0122] Buffer size: The buffer size field identifies the total amount of available data according to the data volume calculation procedure in TS 38.322 and TS 38.323 on all logical channels of the logical channel group after the MAC PDU has been established (i.e., after the logical channel prioritization procedure, which may result in a buffer size field value of zero). The data volume is indicated in bytes. The sizes of the RLC header and the MAC header are not considered in the buffer size calculation. The length of this field for the short BSR format and the short truncated BSR format is 5 bits. The length of this field for the long BSR format and the long truncated BSR format is 8 bits. For the long BSR format and the long truncated BSR format, the buffer size fields are included in ascending order based on LCGi.

[0123] For the long truncated BSR format, the number of buffer size fields included is maximized,

[0124] but does not exceed the number of padding bits.

[0125] Figure 4B is a schematic diagram illustrating the short BSR and the short truncated BSR MAC CE. In this example, one single byte or 8 bits are included in the short BSR and are divided into two fields: a 3-bit LCG ID 402 and a 5-bit buffer size 404. Figure 4C is a schematic diagram illustrating the long BSR and the long truncated BSR MAC CE. In this example, several bytes are included in the long BSR. The first byte is the logical channel group (LCG) information 412 with 8 LCGi bits followed by several bytes, and each byte contains the buffer size 414.

[0126] Figure 5A is a schematic diagram illustrating the combined BSR with the short BSR; and Figure 5B is a schematic diagram illustrating the combined BSR with the long BSR. In the first scenario, the content of the early buffer status report (early BSR) and the normal buffer status report (normal BSR) can be combined into one buffer status report (BSR). The early BSR is a newly introduced BSR for reporting the buffer size based on the expected amount of data to be received. As Figure 1A shown, for example, when the IAB node 2 receives a BSR from the UE2, the buffer size of the data expected to be received will be reported to the parent IAB node, the IAB node 1, in order to reduce the latency. Additionally, the normal buffer status, i.e., the data already available for transmission in the IAB node 2, also needs to be reported to the parent IAB node under the same UL grant. Therefore, both the early BSR and the normal BSR may be combined into one combined BSR. In the second scenario, the early buffer status report and the normal BSR can be separate.

[0127] In one example, referring to Figure 1A the system structure of, the processing can be performed according to the following steps:

[0128] Step 1: The UE2 200 or the IAB node 3 104 accesses the gNB or the IAB donor 106 through multi-hop.

[0129] Step 2: When the BSR is triggered, the UE2 200 or the IAB node 3 104 reports the BSR to the parent IAB node 2.

[0130] Step 3: When the IAB node 2 receives a BSR from the UE2 200 or the sub-IAB node 3, the IAB node 2 can know the amount of data expected to be received. In this step, the DU in the IAB node 2 will transmit the BSR information to the MT in the IAB mode.

[0131] Step 4: The IAB node 2 is triggered to transmit the buffer size of the data expected to be received.

[0132] Step 5: The IAB node 2 transmits the buffer size of the data expected to be received to the parent IAB node 1.

[0133] Step 6: The IAB node 1 will allocate UL grants to the IAB node 2 based on the reported BSR.

[0134] In some embodiments, a "total early buffer size" is used to indicate the total amount of data on all LCGs of the BSR reported by the sub-IAB node 104 or the UE 102. That is, all buffer sizes expected to be received for each LCG can be added up. The "total early buffer size" can be added to Figure 4B and Figure 4C the end of the short BSR and the long (truncated) BSR shown in. To combine the short BSR, a second buffer size 506 can be added to the end of the short BSR to indicate Figure 5A the total early buffer size shown in. To combine with the long (truncated) BSR including the m buffer size fields shown in Figure 5b, a new buffer size m+1 516 can be added to the end of the long (truncated) BSR to indicate the total early buffer size. A new LCID can be assigned to the new combined BSR format, and this new LCID is different from the LCID of the short BSR, the long BSR, or the truncated BSR.

[0135] Figure 5C is a schematic diagram illustrating a combined BSR with a short BSR without an LCG ID; and Figure 5Dis a schematic diagram illustrating a combined BSR with a short BSR including an LCG ID. The buffer sizes received from the sub-IAB node 104 or the UE 102 will be remapped to multiple buffers based on priority information (e.g., the LCG of the receiving node). For example, the buffer states of LCG#1, LCG#2, and LCG#3 from the UE are received by the IAB node 2. Then, LCG#1, LCG#2, and LCG#3 will be remapped to LCG#2, LCG#3, and LCG#4 on the transmission side of the IAB node 2. The three early buffer sizes of LCG#2, LCG#3, and LCG#4 will be placed at the end of the BSR. The number of LCGs can be related to the priority information. In addition, the priority information for each early buffer size can be included in the combined BSR. This can provide a general scheme for the combined buffer state, and Figure 5A and Figure 5B the cases shown in can be special cases of this general scheme.

[0136] In some embodiments, it is desirable to add the buffer size of the received data to the buffer size of the normal data already available in the buffer. For example, the buffer states of LCG#1, LCG#2, and LCG#3 from the UE are received by the IAB node 2. Then, LCG#1, LCG#2, and LCG#3 will be remapped to LCG#2, LCG#3, and LCG#4 on the transmission side of the IAB node 2. The early buffer size of LCG#2 will be added to the buffer size of LCG#2. The same calculation applies to LCG#3 and LCG#4.

[0137] Figure 5E is a schematic diagram illustrating a combined BSR with a long BSR without an LCG ID; and Figure 5F is a schematic diagram illustrating a combined BSR with a long BSR including an LCG ID.

[0138] In an exemplary embodiment, a device - in this case the IAB node 104 - may include: a receiver 314 that receives an indication of a buffer status report (BSR) for data expected to be received; a processor 302 that calculates a first type of buffer size 506 / 516 based on the received indication of the BSR for data expected to be received and / or calculates a second type of buffer size 504 / 514 based on the data currently stored in the buffer; and a transmitter 312 that transmits a buffer status including the first type of buffer size 506 / 516 and / or the second type of buffer size 504 / 514.

[0139] The receiver 314 may receive multiple BSRs from multiple remote devices 102 / 104. The remote devices may include UEs and / or other sub-IAB nodes 104.

[0140] In some embodiments, the received BSRs include multiple logical channel groups for receiving data and a buffer size for each of the logical channel groups; a first type of buffer size 506 / 516 includes an early buffer size that indicates the amount of data expected to be received in the multiple logical channel groups; and the buffer status to be reported is a combined buffer status and further includes a first buffer status that includes information on the first type of buffer size 506 / 516; and a second buffer status that includes a second type of buffer size 504 / 514 described as Figures 5A to 5F the short BSR format or the long BSR format or the long truncated BSR format as shown in

[0141] For example, as Figure 5A shown, the second buffer status includes a second type of buffer size 504 described as the short BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status 506 added to the end of the second buffer status.

[0142] In another example, as Figure 5B shown, the second buffer status includes a buffer size 514 described as the long BSR format or the long truncated BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status 506 added to the end of the long BSR format or the long truncated BSR format.

[0143] In some embodiments, the buffer size 506 / 516 of the first type includes the total early buffer size, which indicates the amount of data expected to be received from the plurality of remote devices up to the media access control protocol data unit (MAC PDU) component. In the case where more than one BSR is received from a sub-IAB node (or UE) before reporting the next BSR, if the BSRs are received from different sub-IAB nodes and / or UEs, the total early buffer size may be the sum of all the received BSRs. All BSRs received from sub-IAB node 104 and / or UE 102 up to the MAC PDU component (the MAC PDU including the BSR MAC CE) are considered for the total early buffer status. Those BSRs that have been received at the IAB node simultaneously with data but for which no further reception is expected are not reported in the early BSRs because the data is now considered to be the IAB node's own data. Alternatively or additionally, the early buffer sizes from different IAB nodes 104 and / or UEs corresponding to the same priority may be cumulated. All BSRs received from sub-IAB nodes and / or UEs up to the MAC PDU component (the MAC PDU including the BSR MAC CE) are considered for the total early buffer status.

[0144] In some embodiments, the receiver receives a plurality of BSRs from a single remote device; and the buffer size of the first type is calculated based on the last received BSR. The single remote device from which the plurality of BSRs are received may be UE120 or sub-IAB node 104. In the case where more than one BSR is received from the same IAB node 104 or UE 102 before reporting the next BSR, the early IAB BSR should only include the buffer status according to the most recently received BSR.

[0145] Optionally, the buffer status to be reported is assigned a logical channel ID (LCID) that is different from the LCID of the short BSR, long BSR, or truncated BSR.

[0146] In some embodiments, as Figures 5C to 5F shown, the received BSR includes a plurality of logical channel groups 512 for receiving data and a buffer size for each of the logical channel groups 514; and the buffer size 516 of the first type is organized according to the priority information. The information of the logical channel group 512 may be used as the priority information.

[0147] For example, the received BSR includes a first received BSR from a first remote device and a second received BSR from a second remote device; the first received BSR includes multiple instances of buffer sizes with priorities; the second received BSR includes multiple instances of buffer sizes with the same priority; and the buffer size values with the same priority from the first received BSR and the second received BSR are accumulated to form the buffer size for the priority. That is, the early buffer sizes from different IAB nodes 104 and / or UEs 102 corresponding to the same priority can be added together.

[0148] In another embodiment, the received BSR includes a first received BSR from a first remote device and a second received BSR from a second remote device; the buffer size with a priority corresponds to a first type of buffer size; the buffer sizes with the same priority correspond to a second type of buffer size; the buffer size values with the same priority from the first type of buffer size and the second type of buffer size are accumulated to form the buffer size for the priority. That is to say, the buffer size of the data expected to be received can be added to the buffer size of the normal data already available in the buffer. For example, the buffer states of LCG#1, LCG#2, and LCG#3 from a UE are received by an IAB node 2. Then, LCG#1, LCG#2, and LCG#3 will be remapped to LCG#2, LCG#3, and LCG#4 on the transmission side of the IAB node 2. The early buffer size of LCG#2 will be added to the buffer size of LCG#2. The same calculation applies to LCG#3 and LCG#4.

[0149] For the truncated BSR format, if the number of included buffer size fields is maximized but does not exceed the number of padding bits, then in the combined BSR, a buffer size needs to be selected. Three exemplary options are provided as follows:

[0150] Option A: The early buffer size for the early BSR should be maintained by priority. The reason is that the 1-bit indication in the legacy BSR format will indicate whether there is available data for transmission in the corresponding LCG. Therefore, optionally, when the available uplink resources for transmitting the buffer state are limited, the first type of buffer size 506 / 516 is included in the buffer state report, which has a higher priority compared to the second type of buffer size 504 / 514.

[0151] Option B: The normal buffer size should be maintained by priority. Therefore, optionally, when the available uplink resources for transmitting the buffer state are limited, the second type of buffer size 504 / 514 is included in the buffer state report, which has a higher priority compared to the first type of buffer size 506 / 516.

[0152] Option C: The buffer sizes corresponding to high priorities should be maintained according to the priorities. For example, both the normal buffer size and the early buffer size are for each LCG. The MAC layer knows the association between the LCG ID and the priority. Thus, optionally, when the available uplink resources for transmitting the buffer status are limited, the information of the buffer sizes with higher priorities from the buffer sizes of the first type 506 / 516 and the buffer sizes of the second type 504 / 514 is included in the buffer status report.

[0153] In some embodiments, the buffer status to be reported further includes information about the logical channel group 518 for transmitting data, as Figures 5C to 5F shown.

[0154] Figure 6A is a schematic diagram illustrating a short early BSR; and Figure 6B is a schematic diagram illustrating a long (truncated) BSR. In the second scenario, the early buffer status (early BSR) and the normal BSR can be separate.

[0155] In one example, as Figure 6A shown, a 'total early buffer size' can also be used to indicate the total quantity of the buffer sizes on all LCGs of the BSR reported by the sub-IAB node 104 or the UE 102. The LCG ID is not included in the early BSR because it is the total quantity. Thus, optionally, the received BSR includes a plurality of logical channel groups for receiving data and the buffer size for each of the logical channel groups; the buffer size of the first type 606 includes the early buffer size, which indicates the amount of data expected to be received in the plurality of logical channel groups.

[0156] Similar to the first scenario, if the IAB node 104 receives more than one BSR from the sub-IAB node 104 and / or the UE 102, different buffer sizes can be accumulated to the same total early buffer size. All BSRs received from the sub-IAB node and / or the UE until the MAC PDU component (the MAC PDU including the BSR MAC CE) are considered for the total early buffer status. Those BSRs that have received data at the IAB node but do not expect to receive any more are not reported in the early BSR because the data is now considered the IAB node's own data. If more than one BSR is received from the same sub-IAB or UE before reporting the next BSR, the early IAB BSR should only include the buffer status according to the most recently received BSR.

[0157] In another example, as Figure 6BAs shown, the buffer sizes received from the child IAB node 104 or the UE 102 will be remapped to multiple buffer sizes based on the priority (e.g., the LCG on the receiving node side). For example, the buffer sizes of LCG#1, LCG#2, and LCG#3 are received by the IAB node 2, and LCG#1, LCG#2, and LCG#3 will be remapped to new LCGs, such as LCG#2, LCG#3, LCG#4 on the receiving parent IAB node side. A dedicated LCID will be assigned to the receiving node to distinguish between the early BSR and the normal BSR.

[0158] Similar to the first scenario, the early buffer sizes from different IAB nodes and / or UEs corresponding to the same priority / LCG can be added together. If more than one BSR is received from the same child IAB or UE before reporting the next BSR, the early IAB BSR should only include the buffer status according to the most recently received BSR.

[0159] Optionally, the received BSR includes multiple logical channel groups for receiving data and the buffer size for each logical channel group; the first type of buffer size 616 is organized according to the priority information. The information of the logical channel group can be used to identify the priority information.

[0160] Similarly, the buffer status to be reported further includes the information of the logical channel group 618 for transmitting data.

[0161] For the truncated BSR format, if the number of included buffer size fields is maximized but does not exceed the number of padding bits, in the combined BSR, it is necessary to select the buffer size. Three exemplary options are provided as follows:

[0162] Option A: The early buffer size for the early BSR should be maintained according to the priority. The reason is that the 1-bit indication in the legacy BSR format will indicate whether there is available data for transmission in the corresponding LCG. Therefore, optionally, when the available uplink resources for transmitting the buffer status are limited, the first type of buffer size 606 / 616 is included in the buffer status report, which has a higher priority compared to the second type of buffer size.

[0163] Option B: The normal buffer size should be maintained according to the priority. Therefore, optionally, when the available uplink resources for transmitting the buffer status are limited, the second type of buffer size is included in the buffer status report, which has a higher priority compared to the first type of buffer size 606 / 616.

[0164] Option C: The buffer size corresponding to the high priority shall be maintained according to the priority. For example, both the normal buffer size and the early buffer size are for each LCG. The MAC layer knows the association between the LCG ID and the priority. Thus, optionally, when the available uplink resources for transmitting the buffer status are limited, the information of the buffer size with higher priority among the buffer sizes of the first type 606 / 616 and the buffer sizes of the second type is included in the buffer status report.

[0165] In another exemplary embodiment, if a BSR including the early buffer size has been triggered and there is no UL-SCH resource available for a new transmission, a scheduling request (SR) corresponding to the logical channel of the IAB node that transmits the early buffer size will be triggered. The SR is associated with one or more LCHs. In the early IAB BSR, the receiving IAB node cannot know which LCH has data available for transmission.

[0166] The SR is a special physical layer message used for the UE to ask the IAB node or the IAB node to ask its parent IAB node or send a UL grant so that the UE or the IAB node can transmit the PUSCH. The UE can then transmit data after receiving the UL grant.

[0167] The SR selection can be determined based on the following principle. The LCG associated with the buffer size reported by the child IAB node or the UE will be remapped to the LCG of the IAB node on the transmission side. The SR configuration of the highest priority LCH of the remapped LCG can be applied. If more than one BSR is received from the child IAB node and / or the UE, the SR selection should consider all the LCGs of the multiple BSRs reported by the child IAB node and / or the UE.

[0168] In one example, referring to Figure 1A the system structure of, the process can be performed according to the following steps:

[0169] Step 1: UE2 200 or IAB node 3 104 accesses the gNB or IAB donor 106 through multi-hop.

[0170] Step 2: When the BSR is triggered, UE2 200 or IAB node 3 104 reports the BSR to the parent IAB node 2.

[0171] Step 3: When IAB node 2 receives the BSR from UE2 200 or child IAB node 3, IAB node 2 can know the amount of data expected to be received. In this step, the DU in IAB node 2 will transmit the BSR information to the MT in IAB mode.

[0172] Step 4: IAB node 2 is triggered to transmit the buffer size of the data expected to be received.

[0173] Step 6: IAB Node 1 allocates UL grants to IAB Node 2 based on the reported BSR.

[0174] Step 5: If a BSR including the early buffer size has been triggered and there are no UL-SCH resources available for new transmissions, a scheduling request (SR) corresponding to the logical channel of the IAB node that transmitted the early buffer size will be triggered.

[0175] Step 6: IAB Node 2 transmits an SR to the parent IAB Node 1.

[0176] Step 7: IAB Node 1 allocates UL resources to IAB Node 2 for BSR transmission.

[0177] Step 8: When receiving the UL resources from IAB Node 1, IAB Node 2 transmits the BSR.

[0178] In some embodiments, the apparatus may include: a receiver 314 that receives a plurality of BSRs from a plurality of remote devices; and a transmitter 312 that transmits an indication of the buffer status of the data expected to be received; wherein, when it is determined that there are no uplink resources available, the transmitter 312 transmits a scheduling request (SR).

[0179] Optionally, the BSR includes a plurality of logical channel groups; a priority value can be obtained from the identification of the logical channel groups; and the transmission of the SR is selected based on the highest priority value of the logical channels included in the plurality of logical channel groups.

[0180] Figure 7 is a flowchart illustrating steps for communicating with BSR processing.

[0181] In step 702, the receiver receives a buffer status report (BSR) indicating the buffer status of the data expected to be received.

[0182] In step 704, the processor calculates a first type of buffer size based on the received BSR indicating the buffer status of the data expected to be received and / or calculates a second type of buffer size based on the data currently stored in the buffer.

[0183] In step 706, the transmitter transmits a buffer status including the first type of buffer size and / or the second type of buffer size.

[0184] The receiver can receive multiple BSRs from multiple remote devices. In some embodiments, the received BSRs include multiple logical channel groups for receiving data and buffer sizes for each logical channel group; the first type of buffer size includes an early buffer size that indicates the amount of data expected to be received in the multiple logical channel groups; and the buffer status to be reported is a combined buffer status and further includes a first buffer status that includes information on the first type of buffer size; and a second buffer status that includes a second type of buffer size described as a short BSR format or a long BSR format or a long truncated BSR format. In one example, the second buffer status includes a second type of buffer size described as a short BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status added to the end of the second buffer status. In another example, the second buffer status includes a buffer size described as a long BSR format or a long truncated BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status added to the end of the long BSR format or the long truncated BSR format.

[0185] In some embodiments, the first type of buffer size includes a total early buffer size that indicates the amount of data expected to be received from the multiple remote devices up to the media access control protocol data unit (MAC PDU) component.

[0186] The receiver can receive multiple BSRs from a single remote device; and the first type of buffer size is calculated based on the last received BSR.

[0187] The buffer status to be reported can be assigned a logical channel ID (LCID) that is different from the LCID of the short BSR, long BSR, or truncated BSR.

[0188] The received BSRs can include multiple logical channel groups for receiving data and buffer sizes for each of the logical channel groups; and the first type of buffer size is organized according to priority information. The information of the logical channel groups can be used as priority information.

[0189] The received BSR can include a first received BSR from a first remote device and a second received BSR from a second remote device; the first received BSR includes multiple instances of buffer sizes with priorities; the second received BSR includes multiple instances of buffer sizes with the same priority; and the buffer size values with the same priority from the first received BSR and the second received BSR are accumulated to form the buffer size of the priority.

[0190] The received BSR may include a first received BSR from a first remote device and a second received BSR from a second remote device; a buffer size with a priority corresponds to a buffer size of a first type; buffer sizes with the same priority correspond to a buffer size of a second type; buffer size values with the same priority from the buffer sizes of the first type and the second type are accumulated to form the buffer size of the priority.

[0191] In some embodiments, when the available uplink resources for transmitting the buffer status are limited, the buffer size of the first type is included in the buffer status report with a higher priority than the buffer size of the second type. Alternatively, when the available uplink resources for transmitting the buffer status are limited, the buffer size of the second type is included in the buffer status report with a higher priority than the buffer size of the first type. Alternatively, when the available uplink resources for transmitting the buffer status are limited, information on buffer sizes with a higher priority from the buffer sizes of the first type and the second type is included in the buffer status report.

[0192] The received BSR includes a plurality of logical channel groups for receiving data and a buffer size for each of the logical channel groups; the buffer size of the first type includes an early buffer size that indicates the amount of data expected to be received in the plurality of logical channel groups.

[0193] The received BSR may include a plurality of logical channel groups for receiving data and a buffer size for each of the logical channel groups; the buffer size of the first type is organized according to priority information. Information on the logical channel groups can be used to identify the priority information.

[0194] The buffer status to be reported may further include information on the logical channel groups for transmitting data.

[0195] Figure 8 is a flowchart illustrating steps for communicating with processing of SR and BSR.

[0196] In step 802, the receiver receives a plurality of BSRs from a plurality of remote devices.

[0197] In step 804, the transmitter transmits a buffer status indicating the expected data to be received.

[0198] In step 806, when it is determined that no uplink resources are available, the transmitter transmits a scheduling request (SR).

[0199] In some embodiments, the BSR includes a plurality of logical channel groups; a priority value can be obtained from the identification of the logical channel groups; and the transmission of the SR is selected based on the highest priority value of the logical channels included in the plurality of logical channel groups.

[0200] Various embodiments and / or examples are disclosed to provide exemplary and explanatory information to enable those of ordinary skill in the art to practice the present disclosure. Features or components disclosed with reference to one embodiment or example are also applicable to all embodiments or examples, unless otherwise specifically stated.

[0201] Embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects only illustrative and not restrictive. Thus, the scope of the invention is indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are embraced within their scope.

Claims

1. An apparatus for communicating using a buffer status report (BSR), comprising: a receiver that receives a BSR indicating a desire to receive data; a processor that calculates a first type of buffer size based on the received BSR indicating a desire to receive data and / or calculates a second type of buffer size based on data currently stored in the buffer; and a transmitter that transmits a buffer status including the first type of buffer size and / or the second type of buffer size, wherein the buffer status to be reported, including the first type of buffer size and / or the second type of buffer size, is assigned an LCID different from the logical channel ID (LCID) of a short BSR, a long BSR, or a truncated BSR.

2. The apparatus according to claim 1, wherein the receiver receives a plurality of BSRs from a plurality of remote devices.

3. The apparatus according to claim 1, wherein the received BSR includes a plurality of logical channel groups for receiving data and a buffer size for each of the logical channel groups; the first type of buffer size includes an early buffer size that indicates the amount of data expected to be received in the plurality of logical channel groups; and the buffer status to be reported is a combined buffer status and further includes a first buffer status that includes information on the first type of buffer size; and a second buffer status that includes the second type of buffer size described in a short BSR format or a long BSR format or a long truncated BSR format.

4. The apparatus according to claim 3, wherein the second buffer status includes the second type of buffer size described in a short BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status added to the end of the second buffer status.

5. The apparatus according to claim 3, wherein the second buffer status includes the buffer size described in a long BSR format or a long truncated BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status added to the end of the long BSR format or the long truncated BSR format.

6. The apparatus according to claim 2, wherein the first type of buffer size includes a total early buffer size that indicates the amount of data expected to be received from the plurality of remote devices until a media access control protocol data unit (MAC PDU) component.

7. The apparatus according to claim 1, wherein the receiver receives a plurality of BSRs from a single remote device; and the first type of buffer size is calculated based on the last received BSR.

8. The apparatus according to claim 1, wherein The received BSR includes a plurality of logical channel groups for receiving data and a buffer size for each of the logical channel groups; and The first type of buffer size is organized according to priority information.

9. The apparatus according to claim 8, wherein The information of the logical channel group is the priority information.

10. The apparatus according to claim 2, wherein The received BSR includes a first received BSR from a first remote device and a second received BSR from a second remote device; The first received BSR includes a plurality of instances of buffer sizes with priorities; The second received BSR includes a plurality of instances of buffer sizes with the same priority; and the buffer size values with the same priority from the first received BSR and the second received BSR are accumulated to form the buffer size of the priority.

11. The apparatus according to claim 1, wherein The received BSR includes a first received BSR from a first remote device and a second received BSR from a second remote device; The buffer size with priority corresponds to the first type of buffer size; The buffer size with the same priority corresponds to the second type of buffer size; The buffer size values with the same priority from the first type of buffer size and the second type of buffer size are accumulated to form the buffer size of the priority.

12. The apparatus according to claim 1, wherein When the available uplink resources for transmitting the buffer status are limited, the first type of buffer size is included in the buffer status report with a higher priority than the second type of buffer size.

13. The apparatus according to claim 1, wherein When the available uplink resources for transmitting the buffer status are limited, the second type of buffer size is included in the buffer status report with a higher priority than the first type of buffer size.

14. The apparatus according to claim 8, wherein When the available uplink resources for transmitting the buffer status are limited, the information of the buffer sizes with higher priority from the first type of buffer size and the second type of buffer size is included in the buffer status report.

15. The apparatus according to claim 1, wherein The received BSR includes a plurality of logical channel groups for receiving data and a buffer size for each logical channel group of the logical channel groups; The first type of buffer size includes an early buffer size, and the early buffer size indicates the amount of data expected to be received in the plurality of logical channel groups.

16. The apparatus according to claim 8, wherein The information of the logical channel group is used to identify the priority information.

17. The apparatus according to claim 1, wherein The buffer status to be reported further includes the information of the logical channel group for transmitting data.

18. A method for communicating using a buffer status report (BSR), comprising: Receiving, by a receiver, a BSR indicating the data expected to be received; Based on the received BSR indicating the expectation to receive data, a processor calculates a buffer size of a first type and / or calculates a buffer size of a second type based on data currently stored in the buffer; and a transmitter transmits a buffer status including the buffer size of the first type and / or the buffer size of the second type, wherein the buffer status including the buffer size of the first type and / or the buffer size of the second type to be reported is assigned an LCID different from the logical channel ID (LCID) of a short BSR, a long BSR, or a truncated BSR.

19. The method according to claim 18, wherein the receiver receives multiple BSRs from multiple remote devices.

20. The method according to claim 18, wherein the received BSRs include multiple logical channel groups for receiving data and a buffer size for each of the logical channel groups; the buffer size of the first type includes an early buffer size, and the early buffer size indicates the amount of data expected to be received in the multiple logical channel groups; and the buffer status to be reported is a combined buffer status and further includes a first buffer status, the first buffer status including information on the buffer size of the first type; and a second buffer status, the second buffer status including the buffer size of the second type described in a short BSR format or a long BSR format or a long truncated BSR format.

21. The method according to claim 20, wherein the second buffer status includes the buffer size of the second type described in a short BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status added to the end of the second buffer status.

22. The method according to claim 20, wherein the second buffer status includes a buffer size described in a long BSR format or a long truncated BSR format; and the combined buffer status to be reported includes the second buffer status and the first buffer status added to the end of the long BSR format or the long truncated BSR format.

23. The method according to claim 19, wherein the buffer size of the first type includes a total early buffer size, and the total early buffer size indicates the amount of data expected to be received from the multiple remote devices until a media access control protocol data unit (MAC PDU) component.

24. The method according to claim 18, wherein the receiver receives multiple BSRs from a single remote device; and the buffer size of the first type is calculated based on the last received BSR.

25. The method according to claim 18, wherein the received BSRs include multiple logical channel groups for receiving data and a buffer size for each of them; and the buffer size of the first type is organized according to priority information.

26. The method according to claim 25, wherein The information of the logical channel group is the priority information.

27. The method according to claim 19, wherein the received BSR includes a first received BSR from a first remote device and a second received BSR from a second remote device; the first received BSR includes multiple instances of buffer sizes with priorities; the second received BSR includes multiple instances of buffer sizes with the same priority; and the buffer size values with the same priority from the first received BSR and the second received BSR are accumulated to form the buffer size of the priority.

28. The method according to claim 18, wherein the received BSR includes a first received BSR from a first remote device and a second received BSR from a second remote device; the buffer size with a priority corresponds to the buffer size of the first type; the buffer size with the same priority corresponds to the buffer size of the second type; the buffer size values with the same priority from the buffer size of the first type and the buffer size of the second type are accumulated to form the buffer size of the priority.

29. The method according to claim 18, wherein when the available uplink resources for transmitting the buffer status are limited, the buffer size of the first type is included in the buffer status report with a higher priority than the buffer size of the second type.

30. The method according to claim 18, wherein when the available uplink resources for transmitting the buffer status are limited, the buffer size of the second type is included in the buffer status report with a higher priority than the buffer size of the first type.

31. The method according to claim 25, wherein when the available uplink resources for transmitting the buffer status are limited, the information of the buffer size with a higher priority from the buffer size of the first type and the buffer size of the second type is included in the buffer status report.

32. The method according to claim 18, wherein the received BSR includes multiple logical channel groups for receiving data and buffer sizes for each of the logical channel groups; the buffer size of the first type includes an early buffer size, and the early buffer size indicates the amount of data expected to be received in the multiple logical channel groups.

33. The method according to claim 25, wherein The information of the logical channel group is used to identify the priority information.

34. The method according to claim 18, wherein The buffer status to be reported further includes the information of the logical channel group for transmitting data.

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