CN110291740B

CN110291740B - Feedback method and device for system information request

Info

Publication number: CN110291740B
Application number: CN201880009727.2A
Authority: CN
Inventors: 约阿希姆·勒尔; 普拉泰克·巴苏马利克; 拉维·库奇波特拉
Original assignee: Motorola Mobility LLC
Current assignee: Motorola Mobility LLC
Priority date: 2017-05-03
Filing date: 2018-05-03
Publication date: 2022-07-19
Anticipated expiration: 2038-05-03
Also published as: EP3619862A1; CN110291740A

Abstract

Apparatuses, methods, and systems for sending and/or receiving feedback for system information requests are disclosed. A method (900) includes sending (902) information indicating a request for system information. The method (900) includes monitoring (904) for a feedback response confirming receipt of the request for system information during a first predetermined time period. The method (900) includes indicating (906) successful completion of the random access procedure in response to receiving the feedback response.

Description

Feedback method and device for system information request

Cross Reference to Related Applications

This application is a continuation-in-part application entitled "feedback on system information request" and U.S. patent application serial No. 15/464,086 filed on 2017, 3, 20, and also claims priority to U.S. provisional patent application serial No. 62/500,959 entitled "feedback mechanism for on-demand system information acquisition process" and filed on 2017, 5, 3, the entire contents of which are incorporated herein by reference in their entirety.

Technical Field

The subject matter disclosed herein relates generally to wireless communications, and more particularly to feedback for system information requests.

Background

The following abbreviations are defined herein, at least some of which are referred to in the following description: third generation partnership project ("3 GPP"), acknowledgement ("ACK"), binary phase shift keying ("BPSK"), clear channel assessment ("CCA"), cyclic prefix ("CP"), cell radio network temporary identifier ("C-RNTI"), channel state information ("CSI"), common search spaces ("CSS"), discrete fourier transform extensions ("DFTS"), downlink control information ("DCI"), downlink ("DL"), downlink pilot time slots ("DwPTS"), enhanced clear channel assessment ("eCCA"), enhanced mobile broadband ("eMBB"), evolved node B ("eNB"), european telecommunications standards institute ("ETSI"), frame-based device ("FBE"), frequency division duplex ("FDD"), frequency division multiple access ("FDMA"), guard period ("GP"), hybrid automatic repeat request ("HARQ"), "etc, An identifier ("ID"), an internet of things ("IoT"), a licensed-assisted access ("LAA"), a load-based device ("LBE"), listen-before-talk ("LBT"), long term evolution ("LTE"), a medium access control ("MAC"), multiple access ("MA"), a modulation and coding scheme ("MCS"), machine type communication ("MTC"), multiple-input multiple-output ("MIMO"), multiple-user shared access ("MUSA"), a narrowband ("NB"), a negative acknowledgement ("NACK") or ("NAK"), a next generation node B ("gbb"), a non-orthogonal multiple access ("NOMA"), orthogonal frequency division multiplexing ("OFDM"), a primary cell ("PCell"), a physical broadcast channel ("PBCH"), a physical downlink control channel ("PDCCH"), a physical downlink shared channel ("PDSCH"), a pattern division multiple access ("PDMA"), a protocol data unit ("PDU"),(s), Physical hybrid ARQ indicator channel ("PHICH"), physical layer ("PHY"), physical random access channel ("PRACH"), physical resource block ("PRB"), physical uplink control channel ("PUCCH"), physical uplink shared channel ("PUSCH"), quality of service ("QoS"), quadrature phase shift keying ("QPSK"), radio resource control ("RRC"), random access procedure ("RACH"), random access response ("RAR"), random access radio network temporary identifier ("RA-RNTI"), reference signal ("RS"), resource extended multiple access ("RSMA"), round trip time ("RTT"), receive ("RX"), sparse code multiple access ("SCMA"), scheduling request ("SR"), Single Carrier frequency division multiple Access ("SC-FDMA"), Secondary cell ("SCell"), shared channel ("SCH"), "physical layer (" PHY "), physical random Access channel (" PRACH "), physical resource Block (" PRB "), physical uplink control channel (" PUCCH "), random Access procedure (" RACH "), random Access response (" RAR "), random Access radio network temporary identifier (" RA-RNTI "), reference Signal (" RSMA "), resource extended multiple Access (" RSMA "), round trip time indicator (" RTT "), random Access (" RST-indicator ("RST"), random Access ("RSA"), scheduling request ("RST-indicator (" RST "), scheduling request (" SCell "), and scheduling request (" SCell ") of the physical indicator (" RST-indicator channel ("RSCH") may be used for the physical indicator channel ("RSCH") in the physical indicator channel, or the physical indicator of the physical indicator channel ("RSCH, or the physical indicator of the physical indicator (" PRCH) may be used for the physical indicator, Signal to interference plus noise ratio ("SINR"), system information blocks ("SIBs"), timing advance groups ("TAGs"), transport blocks ("TBs"), transport block size ("TBs"), time division duplex ("TDD"), time division multiplex ("TDM"), transmission time interval ("TTI"), transmit ("TX"), uplink control information ("UCI"), user entity/device (mobile terminal) ("UE"), uplink ("UL"), universal mobile telecommunications system ("UMTS"), uplink pilot time slot ("UpPTS"), super-reliability and low-delay communications ("URLLC"), and worldwide interoperability for microwave access ("WiMAX"). As used herein, "HARQ-ACK" may collectively refer to acknowledgement ("ACK") and negative acknowledgement ("NAK"). ACK means that the TB is correctly received, and NAK means that the TB is incorrectly received.

In some wireless communication networks, some system information may be transmitted and/or received more frequently than necessary. In some configurations, a minimum amount of system information may be used in order to reduce the signaling load for providing system information. The minimum system information ("SI") may contain basic information (e.g., subframe number, public land mobile network list ("PLMN"), cell camping parameters, RACH parameters) for initially accessing the cell, which is periodically broadcast in the cell. In some configurations, other non-minimum SIs do not necessarily need to be broadcast periodically (e.g., it may be a network decision). In various configurations, other SIs may be provided to the UE on demand (e.g., the UE may request the other SIs). The delivery of other SIs may be done in a broadcast or unicast fashion. In some configurations, the minimum SI may indicate whether to broadcast periodically or provide specific SIBs on demand. To obtain one or more SIBs that are not periodically broadcast and provided on-demand, the UE may initiate an on-demand SI acquisition procedure (e.g., SI request). For the SI used by the UE, the UE may determine whether the SI is available in the cell and is broadcast before it sends a request for the SI. The scheduling information of the other SIs may be provided by a minimum SI (e.g., SIB type, validity information, periodicity, SI window information, etc.).

In various configurations, the UE may not be aware of whether the gNB correctly detected the SI request, and may unnecessarily monitor for delivery of the requested SI during the SI window. Thus, the UE battery may be unnecessarily drained and there may be an increase in delay for SI provisioning.

Disclosure of Invention

Methods for sending and/or receiving feedback for system information requests are disclosed. The apparatus and system also perform the functions of the apparatus. In one embodiment, the method includes transmitting information indicating a request for system information. In some embodiments, the method includes monitoring for a feedback response acknowledging receipt of the request for system information during the first predetermined time period. In some embodiments, the method includes indicating successful completion of the random access procedure in response to receiving the feedback response.

In one embodiment, the feedback response is part of a random access response message sent on a physical downlink shared channel. In yet another embodiment, the information indicating the request for system information includes a physical random access channel preamble. In some embodiments, the feedback response includes a physical random access channel preamble identifier corresponding to the physical random access channel preamble. In various embodiments, a feedback response acknowledging receipt of the request for system information is sent in a medium access control subheader that includes a physical random channel preamble identifier. In some embodiments, the method comprises, in response to not receiving the feedback response: retransmitting information indicating a request for system information; during a second predetermined time period, a feedback response is monitored confirming receipt of the request for system information.

In some embodiments, retransmitting information indicative of a request for system information comprises retransmitting information using increased power. In some embodiments, retransmitting the information indicating the request for system information includes repeatedly transmitting the information indicating the request for system information up to a predetermined number of times. In one embodiment, the method includes receiving scheduling information corresponding to system information. In some embodiments, the method includes, in response to receiving the feedback response, receiving system information based on the scheduling information.

In some embodiments, the feedback response is part of the downlink control information. In various embodiments, a radio network temporary identifier is used to indicate the feedback response. In some embodiments, the method includes not setting the cell radio network temporary identifier to a value in the feedback response. In one embodiment, the feedback response is indicated by one or more fields of the downlink control information being set to one or more predefined values. In some embodiments, the information indicating the request for system information is part of a message 3 transmission during random access. In various embodiments, the information indicating the request for system information comprises a bitmap indicating the requested system information. In some embodiments, the feedback response includes information indicative of the requested system information. In some embodiments, the feedback response is part of a contention resolution message during random access. In various embodiments, the downlink scheduling information for the system information is sent with a feedback response.

In one embodiment, an apparatus for receiving feedback on a system information request includes a transmitter that transmits information indicating a request for system information. In various embodiments, the apparatus includes a receiver that monitors for a feedback response acknowledging receipt of the request for system information during a first predetermined time period. In some embodiments, the apparatus includes a processor that indicates successful completion of the random access procedure in response to receiving a feedback response.

In one embodiment, a method includes receiving information from a remote unit indicating a request for system information. In various embodiments, the method includes sending a feedback response to the remote unit acknowledging receipt of the request for system information, wherein the remote unit indicates successful completion of the remote access procedure in response to receiving the feedback response.

In one embodiment, the method includes transmitting scheduling information corresponding to system information. In yet another embodiment, the method includes transmitting system information based on the scheduling information. In some embodiments, the feedback response is part of the downlink control information. In some embodiments, a radio network temporary identifier is used to indicate the feedback response. In various embodiments, the feedback response is indicated by one or more fields of the downlink control information being set to one or more predefined values. In one embodiment, the feedback response is part of a random access response message sent on a physical downlink shared channel. In some embodiments, the information indicating the request for system information comprises a physical random access channel preamble.

In some embodiments, the feedback response includes a physical random access channel preamble identifier corresponding to the physical random access channel preamble. In various embodiments, the feedback response is sent in a medium access control subheader that includes a physical random channel preamble identifier. In some embodiments, the information indicating the request for system information is part of a message 3 transmission during random access. In one embodiment, the information indicating the request for system information comprises a bitmap indicating the requested system information. In some embodiments, the feedback response includes information indicative of the requested system information. In various embodiments, the feedback response is part of a contention resolution message during random access. In one embodiment, the downlink scheduling information for the system information is transmitted using a feedback response.

In one embodiment, an apparatus for sending feedback on a system information request includes a receiver that receives information from a remote unit indicating a request for system information. In some embodiments, the apparatus includes a transmitter that transmits a feedback response to the remote unit acknowledging receipt of the request for system information, wherein the remote unit indicates successful completion of the remote access procedure in response to receiving the feedback response.

Drawings

A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered to be limiting of its scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

fig. 1 is a schematic block diagram illustrating one embodiment of a wireless communication system for sending and/or receiving feedback for a system information request;

FIG. 2 is a schematic block diagram illustrating one embodiment of an apparatus that may be used to receive feedback on a system information request;

FIG. 3 is a schematic block diagram illustrating one embodiment of an apparatus that may be used to send feedback for a system information request;

FIG. 4 illustrates one embodiment of communications for sending and receiving feedback for a system information request;

fig. 5 illustrates another embodiment of communications for sending and receiving feedback for a system information request;

FIG. 6 is a schematic flow chart diagram illustrating one embodiment of a method for receiving feedback on a system information request;

FIG. 7 is a schematic flow chart diagram illustrating one embodiment of a method for sending feedback for a system information request;

FIG. 8 illustrates one embodiment of a MAC PDU;

FIG. 9 is a schematic flow chart diagram illustrating one embodiment of a method for monitoring feedback responses acknowledging system information requests; and

figure 10 is a schematic flow chart diagram illustrating one embodiment of a method for sending a feedback response to a remote unit acknowledging receipt of a request for system information.

Detailed Description

As will be appreciated by one 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, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "circuit," module "or" system. Furthermore, embodiments may take the form of a program product embodied in one or more computer-readable storage devices that store machine-readable code, computer-readable code, and/or program code, referred to hereinafter as code. The storage device may be tangible, non-transitory, and/or non-transmissive. The storage device may not embody the signal. In a certain embodiment, the storage device only employs signals for the access codes.

Some of the functional units described in this specification may be labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom very large scale integration ("VLSI") circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

Modules may also be implemented in code and/or software for execution by various types of processors. An identified module of code may, for instance, comprise one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.

Indeed, a module of code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different computer-readable storage devices. Where a module or portions of a module are implemented in software, the software portions are stored on one or more computer-readable storage devices.

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

More specific examples (a non-exhaustive list) of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, 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 document, 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.

The code for performing the operations of an embodiment may be any number of lines and may be written in any combination including one or more of an object oriented programming language such as Python, Ruby, Java, Smalltalk, C + +, etc., and conventional procedural programming languages, such as the "C" programming language, and/or a machine language, such as assembly language. The code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer, partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network ("LAN") or a wide area network ("WAN"), or the connection may be made to an external computer (for example, through the Internet using an Internet service provider).

Reference in the specification to "one embodiment," "an embodiment," or similar language means 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," and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "include," "have," and variations thereof mean "including but not limited to," unless expressly specified otherwise. The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms "a", "an" and "the" also mean "one or more", unless expressly specified otherwise.

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 embodiments. One skilled in the relevant art will recognize, however, that an embodiment may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the embodiments.

Aspects of the embodiments are described below with reference to schematic flow charts and/or schematic block diagrams of methods, apparatuses, systems, and program products according to the embodiments. It will be understood that each block of the schematic flow chart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flow chart diagrams and/or schematic block diagrams, can be implemented by code. The code can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the schematic flowchart and/or schematic block diagram block or blocks.

The code may also be stored in a memory device that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the memory device produce an article of manufacture including instructions which implement the function/act specified in the schematic flowchart and/or schematic block diagram block or blocks.

The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause 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 which executes on the computer or other programmable apparatus provides processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

The schematic flow charts and/or schematic block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, systems, methods and program products according to various embodiments. In this regard, each block in the schematic flow chart diagrams and/or schematic block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s).

It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, of the illustrated figure.

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

The description of the elements in each figure may refer to elements of the previous figures. Like numbers refer to like elements throughout, including alternative embodiments of the same elements.

Fig. 1 depicts an embodiment of a wireless communication system 100 for sending and/or receiving feedback for a system information request. In one embodiment, wireless communication system 100 includes a remote unit 102 and a base unit 104. Even though a particular number of remote units 102 and base units 104 are depicted in fig. 1, those skilled in the art will recognize that any number of remote units 102 and base units 104 may be included in the wireless communication system 100.

In one embodiment, remote unit 102 may include a computing device such as a desktop computer, a laptop computer, a personal digital assistant ("PDA"), a tablet computer, a smart phone, a smart television (e.g., a television connected to the internet), a set-top box, a game console, a security system (including a security camera), an in-vehicle computer, a network device (e.g., a router, switch, modem), and so forth. In some embodiments, remote unit 102 includes a wearable device, such as a smart watch, a fitness band, an optical head-mounted display, and so forth. Moreover, remote unit 102 may be referred to as a subscriber unit, mobile device, mobile station, user, terminal, mobile terminal, fixed terminal, subscriber station, UE, user terminal, device, or other terminology used in the art. Remote unit 102 may communicate directly with one or more base units 104 via UL communication signals.

Base units 104 may be distributed over a geographic area. In certain embodiments, base station unit 104 may also be referred to as an access point, access terminal, base station, node-B, eNB, gNB, home node-B, relay node, device, or any other terminology used in the art. The base units 104 are typically part of a radio access network that includes one or more controllers communicatively coupled to one or more corresponding base units 104. The radio access networks are typically communicatively coupled to one or more core networks, which may be coupled to other networks, such as the internet and public switched telephone networks, among others. These and other elements of the radio access and core networks are not illustrated but are generally well known to those of ordinary skill in the art.

In one embodiment, wireless communication system 100 conforms to the NR protocol standardized in 3GPP, where base unit 104 transmits on the DL using an OFDM modulation scheme and remote unit 102 transmits on the UL using an SC-FDMA scheme or an OFDM scheme. More generally, however, the wireless communication system 100 may implement some other open or proprietary communication protocol, such as WiMAX, among other protocols. The present disclosure is not intended to be limited to implementation by any particular wireless communication system architecture or protocol.

Base unit 104 can serve multiple remote units 102 within a service area (e.g., a cell or cell sector) via wireless communication links. Base unit 104 transmits DL communication signals in the time, frequency, and/or spatial domains to serve remote unit 102.

In one embodiment, base unit 104 may receive information from remote unit 102 indicating a request for system information. In some embodiments, base unit 104 may send a feedback response to remote unit 102 indicating that a request for system information has been received. Thus, base unit 104 may be used to send feedback for system information requests.

In another embodiment, the remote unit 102 may transmit information indicating a request for system information. The remote unit 102 may monitor for a feedback response indicating that a request for system information has been received during a predetermined period of time. Thus, the remote unit 102 may be used to receive feedback on the system information request.

Fig. 2 depicts one embodiment of an apparatus 200 that may be used to receive feedback on a system information request. The apparatus 200 includes one embodiment of the remote unit 102. In addition, remote unit 102 may include a processor 202, memory 204, input device 206, display 208, transmitter 210, and receiver 212. In some embodiments, the input device 206 and the display 208 are combined into a single device, such as a touch screen. In some embodiments, remote unit 102 may not include any input device 206 and/or display 208. In various embodiments, the remote unit 102 may include one or more of the processor 202, the memory 204, the transmitter 210, and the receiver 212, and may not include the input device 206 and/or the display 208.

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, microprocessor, central processing unit ("CPU"), graphics processor ("GPU"), auxiliary processing unit, field programmable gate array ("FPGA"), or similar programmable controller. In some embodiments, the processor 202 executes instructions stored in the memory 204 to perform the methods and routines described herein. In various embodiments, processor 202 monitors for a feedback response indicating receipt of the request for system information during a predetermined time period. The processor 202 is communicatively coupled to a memory 204, an input device 206, a display 208, a transmitter 210, and a receiver 212.

In one embodiment, memory 204 is a computer-readable storage medium. In some embodiments, 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, memory 204 includes non-volatile computer storage media. For example, memory 204 may include a hard drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, memory 204 includes both volatile and nonvolatile computer storage media. In some embodiments, memory 204 stores data related to system information. In some embodiments, memory 204 also stores program code and related data, such as an operating system or other controller algorithms operating on remote unit 102.

In one embodiment, input device 206 may comprise any known computer input device, including a touchpad, buttons, keyboard, stylus, microphone, and the like. In some embodiments, the input device 206 may be integrated with the display 208, for example, as a touch screen or similar touch sensitive display. In some embodiments, the input device 206 includes a touch screen such that text may be entered 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 touchpad.

In one embodiment, the display 208 may comprise any known electronically controllable display or display device. The display 208 may be designed to output visual, audible, and/or tactile signals. In some embodiments, display 208 comprises 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 similar display device capable of outputting images, text, and the like to a user. As another non-limiting example, display 208 may include a wearable display such as a smart watch, smart glasses, heads-up display, and the like. Further, the display 208 may be a component of a smart phone, a personal digital assistant, a television, a desktop computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.

In certain embodiments, the display 208 includes one or more speakers for producing sound. For example, the display 208 may produce an audible alarm or notification (e.g., beeping or chime). In some embodiments, display 208 includes one or more haptic devices for generating vibration, motion, or other haptic feedback. In some embodiments, all or part of the display 208 may be integrated with the input device 206. For example, the input device 206 and the display 208 may form a touch screen or similar touch sensitive display. In other embodiments, the display 208 may be located near the input device 206.

Transmitter 210 is used to provide UL communication signals to base unit 104 and receiver 212 is used to receive DL communication signals from base unit 104. In various embodiments, the transmitter 210 may be used to transmit information indicating a request for system information. Although only one transmitter 210 and one receiver 212 are illustrated, remote unit 102 may have any suitable number of transmitters 210 and receivers 212. The transmitter 210 and receiver 212 may be any suitable type of transmitter and receiver. In one embodiment, the transmitter 210 and receiver 212 may be part of a transceiver.

Fig. 3 depicts one embodiment of an apparatus 300 that may be used to send feedback for a system information request. Apparatus 300 includes one embodiment of base unit 104. Further, base unit 104 may include a processor 302, a memory 304, an input device 306, a display 308, a transmitter 310, and a receiver 312. It is to be appreciated that the processor 302, memory 304, input device 306, display 308, transmitter 310, and receiver 312 can be substantially similar to the processor 202, memory 204, input device 206, display 208, transmitter 210, and receiver 212, respectively, of the remote unit 102.

In various embodiments, the receiver 312 is used to receive information from the remote unit 102 indicating a request for system information. In some embodiments, the transmitter 310 may be used to transmit a feedback response to the remote unit 102 indicating receipt of the request for system information. Although only one transmitter 310 and one receiver 312 are illustrated, the base unit 104 may have any suitable number of transmitters 310 and receivers 312. The transmitter 310 and receiver 312 may be any suitable type of transmitter and receiver. In one embodiment, the transmitter 310 and receiver 312 may be part of a transceiver.

Fig. 4 illustrates one embodiment of communications 400 for sending and receiving feedback for a system information request. In particular, communication 400 between UE 402 and gNB 404 is illustrated. The communications 400 may facilitate the UE 402 requesting an on-demand SIB using a RACH message 3-based approach.

In certain embodiments, the gNB 404 may send periodic broadcasts 406 to the UE 402. The periodic broadcast 406 may include a minimum SI used by the UE 402 for communication. In various embodiments, the UE 402 may send a PRACH preamble 408 to the gNB 404. In some embodiments, in response to sending the PRACH preamble 408, the gNB 404 may send the UL grant in a random access response 410. After receiving the random access response 410, the UE 402 may send a system information ("SI") request 412 to the gNB 404 indicating the on-demand SIBs requested by the UE 402. The system information request 412 may be a random access message 3. It is to be appreciated that the on-demand SIB may not be broadcast (e.g., transmitted) unless requested. In response to system information request 412, gNB 404 may send a feedback response 414 indicating that gNB 404 received system information request 412.

In certain embodiments, because message 3 is an UL-SCH transmission (e.g., a medium access control ("MAC") protocol data unit ("PDU")), the UE 402 may provide more information within message 3 than the PRACH preamble. In one embodiment, the UE 402 includes a MAC control element ("CE") within RACH message 3 to transmit SI request information. In such embodiments, the MAC CE may contain a bitmap indicating the SI/SIBs that the UE 402 wants to acquire. Further, the bitmap may have entries for all on-demand SI/SIBs (e.g., all SIBs not broadcast in a cell). Using the bitmap, the UE 402 may indicate which of the SI/SIBs it wants to acquire (e.g., by setting the corresponding field/bit to a predetermined value). In certain embodiments, the UE 402 requests system information not only for the current cell (e.g., the cell on which the UE is camped/connected) but also for neighboring cells. In one embodiment, UE 402 includes information within message 3 (e.g., an SI request message) indicating that the gNB 404 should provide all system information used in a predetermined area covering one or more cells to UE 402. In certain embodiments, the UE 402 may include an RRC message within message 3 to convey SI request information. In such embodiments, the RRC message may contain the SI/SIB the UE 402 wants to acquire.

In various embodiments, some SI may be related to capabilities of the UE 402, and thus indicating that such capabilities may provide useful information to the gNB 404 as to whether to respond with related SI information sent to the UE 402. In certain embodiments, to allow the gNB 404 to allocate sufficient uplink resources for transmission of the SI request bitmap MAC CE in message 3, one or more PRACH preambles may be used to indicate that the purpose of the RACH procedure is for on-demand SI acquisition. In various embodiments, the size of message 3 (e.g., system information request 412) may be different for initial access and SI requests (e.g., message 3 for on-demand SI acquisition may include only a system information request message, but no further information, such as identifying the identity of the UE or certain buffer status reports). In certain embodiments, the content of the RACH response message (e.g., RACH message 2) sent by the gNB in response to receiving the PRACH preamble may be different for RACH procedures with the purpose of on-demand SI acquisition than for other purposes. In some embodiments, the collision of message 3 may occur because more than one UE may send the same reserved PRACH preamble for SI request (e.g., multiple UEs are sending SI request MAC CEs (with different content) on UL resources allocated in RACH message 3). Thus, in certain embodiments, collision/contention resolution may be used to enable the UE 402 to know whether a transmitted SI request was received by the gNB 404. In one embodiment, the gNB 404 may send the SI request bitmap MAC CE it received in message 3 in RACH message 4 (e.g., feedback response 414). This would enable UE 402 to identify whether or not gNB 404 correctly received its SI request. In various embodiments, the gNB 404 may include the requested SIB/SI in RACH message 4 as part of the feedback response 414 (e.g., an RRC message). In some embodiments, upon receiving RACH message 4, UE 402 may check whether the requested SIB/SI is included by decoding the MAC CE (e.g., checking whether the received MAC CE matches the SI request MAC CE sent in message 3). In embodiments where the MAC CE matches the SI request MAC CE, the SIB/SI may be delivered to the RRC. In embodiments where the MAC CE does not match the request, the UE 402 may again trigger the SI acquisition procedure (e.g., send PRACH preamble for SI request, resend message 3, etc.). Further, the UE 402 may monitor (e.g., during a particular time window, during a predetermined time period) for RACH message 4 when transmitting message 3. In the case where RACH message 4 is not received during the predetermined time period, the UE 402 may trigger the SI acquisition procedure again (e.g., transmit PRACH preamble for SI request, retransmit message 3, etc.).

In various embodiments, the SIBs/SIs requested by the UE 402 may be broadcast (instead of sending them in message 4). In such embodiments, RACH message 4 may include scheduling information indicating timing information for broadcasting the requested SIB/SI. Further, in such embodiments, the UE 402 may not read the minimum system information in order to acquire timing information prior to receiving the broadcasted SIB/SI.

In various embodiments, the SIB/SI requested by the UE 402 may be provided in part by broadcast and in part within the RACH message 4. In one embodiment, RACH message 4 may include information indicating which SI/SIBs are provided by RACH message 4 and which SI/SIBs are broadcast (e.g., UE 402 monitors the received broadcast channel during the SI window associated with these SI/SIBs).

In one embodiment, the gNB 404 may send multiple RACH messages 4 (e.g., the SI/SIB to be provided may not fit within only one downlink transmission). In certain embodiments, an indication is included within RACH message 4 (e.g., SI feedback response) indicating whether the UE 402 should continue to monitor for further downlink transmissions (e.g., further RACH message 4 transmissions) to receive additional SI/SIBs or whether the UE may stop monitoring for further downlink transmissions (e.g., further RACH message 4 transmissions). In one embodiment, this indication is a boolean flag. In various embodiments, RACH message 4 may include information indicating whether UE 402 should initiate an RRC connection setup procedure or an RRC connection recovery procedure in response to receiving the RACH message.

It will be appreciated that one advantage of including the SI request bitmap MAC CE in message 4 is that collision/contention resolution can be performed at the MAC level. In certain embodiments, the UE 402 may read the minimum SI and check whether the gNB 404 indicates that the requested SIB is responsive to having received the SI request broadcast in the cell after sending RACH message 3 and after receiving the HARQ acknowledgement as feedback response 414. In such embodiments, conflict/contention resolution will occur at the minimum SI level.

In some embodiments, the radio network temporary identifier ("RNTI") used for RACH message 4 transmission may indicate the on-demand SIB that is included in message 4 (e.g., RRC message) or is being broadcast. In such embodiments, a certain number of RNTIs (e.g., from the cell RNTI ("C-RNTI") space) may be reserved and associated with a particular SIB or combination of SIBs. Further, the UE 402 may monitor (e.g., during a particular time window, during a predetermined time period) the PDCCH addressed to one of those reserved RNTIs when transmitting message 3. Thus, depending on the PDCCH/RNTI received (e.g., feedback response 414), UE 402 can be aware of whether or not gNB 404 received its SI request sent in message 3. In various embodiments, the RNTI used for RACH message 4 may be a common predefined RNTI value. In such embodiments, a common predefined RNTI is used, which is specific to the SI request. Furthermore, in such embodiments, there is no need to allocate/signal a temporary cell RNTI ("T-CRNTI") in the RACH response message. In embodiments using a common RNTI, RACH message 4 (e.g., SI feedback message) may be addressed not only to a single UE, but also to multiple UEs sending SI requests. In this way, each UE sending an SI request may check whether its request is received by the gNB 404 based on the common RNTI. In embodiments where a common RNTI is used for RACH message 4, the transmission of the SI feedback message within RACH message 4 may contain a bitmap indicating that the gbb 404 has received the requested SIB (e.g., multiple requests from different UEs). In this way, each UE sending an SI request may check whether its request was received by the gNB 404 based on the received bitmap. In some embodiments, UEs that have not sent SI requests may monitor the common RNTI in order to receive SI feedback messages (e.g., RACH message 4) and check for requested SIBs, such that the UE may not need to request SIBs that have been requested by other UEs.

In certain embodiments described herein, the RACH procedure may be used for the sole purpose of requesting SI on demand. However, in some embodiments, the UE 402 may establish an RRC connection and simultaneously request an on-demand SI, or the UE 402 in an inactive state may send UL data and simultaneously trigger an on-demand SI acquisition procedure. In such embodiments, by way of example only, the UE 402 may transmit the SI request MAC CE and RRC connection request message in RACH message 3, or the SI request MAC CE and UL data and possibly some buffer status report ("BSR") MAC CE in RACH message 3. In such embodiments, gNB 404 may distinguish between different scenarios (e.g., SI request plus initial access, SI request plus UL data) so that therefore gNB 404 may slice the size of the UL grant. Thus, in some embodiments, the PRACH preamble may be reserved for identifying different cases.

Fig. 5 illustrates another embodiment of communications 500 for sending and receiving feedback for a system information request. In particular, communication 500 between a UE 502 and a gNB 504 is illustrated. The communications 500 may facilitate the UE 502 requesting the on-demand SIB using a method based on RACH message 1.

In certain embodiments, the gNB 504 may send a periodic broadcast 506 to the UE 502. The periodic broadcast 506 may include a minimum SI used by the UE 502 for communication. In various embodiments, the UE 502 may send the PRACH preamble 508 to the gNB 504. The PRACH preamble 508 indicates an SI request to the gNB 504, which indicates the on-demand SIBs requested by the UE 502. The PRACH preamble 508 may be message 1. It is to be appreciated that the on-demand SIBs may not be broadcast (e.g., transmitted) unless requested. In response to the PRACH preamble 508, the gNB 504 may send a feedback response 510 indicating that the PRACH preamble 508 was received by the gNB 504.

In certain embodiments, the PRACH preamble 508 is a specific resource of a SIB or set of SIBs that the UE 502 wants to obtain. In some embodiments, the PRACH preamble 508, which is a specific resource for each SIB or set of SIBs, is reserved and indicated in the minimum SI that is periodically broadcast. In certain embodiments, the UE 502 may request system information not only for the current cell (e.g., the cell on which the UE is camped/connected) but also for neighboring cells. In one embodiment, the PRACH preamble 508 indicates that the gNB 504 should provide the UE 502 with all system information used in a predetermined area covering one or more cells.

Upon transmission of the PRACH preamble 508 (e.g., SI request preamble), the UE 502 may monitor for a feedback message (e.g., feedback response 510) sent from the gNB 504. The UE 502 may monitor for feedback messages during a defined time period (e.g., a time window). Upon receiving the feedback message, the UE 502 may monitor the requested SI during the signaled SI window (e.g., as indicated in scheduling information broadcast in the minimum SI).

In the absence of a feedback message, the UE 502 may assume that the gNB 504 does not detect PRACH transmission and, in some embodiments, may retransmit the PRACH preamble 508 (e.g., SI request). In some embodiments, the PRACH preamble 508 may be retransmitted at an increased transmission power. In various embodiments, a counter is used and initially set to zero and incremented for each PRACH preamble 508 transmission. In certain embodiments, there may be a defined maximum number of PRACH preamble 508 transmission attempts. In some embodiments, the UE 502 may indicate a random access problem to higher layers (e.g., such as a radio link failure procedure may be started for an inactive mode) if a maximum number of transmission attempts of the PRACH preamble 508 is reached.

In some embodiments, a new physical layer ("PHY") signal may be used to convey the feedback message. In various embodiments, the feedback message itself may include a PRACH preamble identifier field identifying the detected PRACH preamble 508. In certain embodiments, the DCI (e.g., PDCCH) may contain the PRACH preamble 508ID detected by the gNB 504. In one embodiment, the DCI format (e.g., format 1A) used to schedule downlink data transmissions may be used to send feedback on the received SI request. In some embodiments, a new RNTI value (e.g., SI-request RNTI) may be used to indicate that the DCI (e.g., PDCCH) includes the SI request feedback message. This may enable UE 502 to distinguish between random access response messages (e.g., a cyclic redundancy check ("CRC") scrambled with a random access RNTI ("RA-RNTI")) and SI request feedback messages (e.g., a CRC of a PDCCH scrambled with an SI request RNTI. in various embodiments, the DCI itself may contain the PRACH preamble (or an indicator identifying the PRACH preamble 508) because the corresponding PDSCH (e.g., PDCCH (DCI only)) is not transmitted-in some embodiments, instead of signaling the detected PRACH preamble 508ID, the gNB 504 may signal a list of detected PRACH preamble IDs, including PRACH preambles detected from other UEs. This feedback message may also indicate which SIBs the gNB 504 (subsequently) will provide (e.g., by broadcast). In some embodiments, the feedback message (DCI) may contain a bitmap indicating that the requested SIB was received and provided accordingly by broadcast/unicast.

In various embodiments, the UE 502 may receive a request to perform a random access procedure for a different purpose than on-demand SI acquisition (e.g., initial access) while also being triggered to perform SI acquisition. In such embodiments, the UE 502 may prioritize the RACH procedures for SI requests. For example, the UE 502 may first perform initial access and then retrieve system information through dedicated signaling (e.g., RRC signaling).

In some embodiments, the SI request feedback message may be sent by means of a PDCCH scrambled with an RA-RNTI (e.g., RACH response). In such embodiments, a predefined value of a field or combination of fields within the DCI may indicate whether the DCI is used for a normal RACH response or as an SI request feedback message.

In various embodiments, the PDSCH is not required to transmit feedback messages (e.g., the feedback is included in the DCI/PDCCH). In such embodiments, the feedback may be a single PRACH preamble ID, a PRACH preamble ID list, a bitmap indicating requested SIBs to be provided by the broadcast. In some embodiments, the RA-RNTI value may be a reserved RA-RNTI value (e.g., not calculated from the time/resources at which the preamble is sent). In such embodiments, the RA-RNTI may be dedicated/specific to the SI request.

In various embodiments, the SI request feedback is sent within a RACH response message sent on the PDSCH (e.g., MAC PDU). In some embodiments, the UE 502 monitors for a RACH response message (e.g., a PDCCH addressed to an RA-RNTI calculated from the time/resources at which the preamble was transmitted) while transmitting the PRACH preamble 508 during the RACH response window. In such embodiments, the RACH response message may be a MAC PDU, which consists of a MAC header and a corresponding MAC random access response ("MAC RAR"). In some embodiments, the MAC PDU header comprises one or more MAC PDU subheaders. Further, each subheader corresponds to a MAC RAR (e.g., in addition to a backoff indicator subheader). In one embodiment, the MAC PDU subheader for the RAR contains a PRACH preamble 508ID field that identifies the random access transmitted. In some embodiments, the RAR message itself includes the following information: temporary C-RNTI: the gNB 504 provides the UE 502 with another identifier, referred to as a temporary C-RNTI, for further communication; timing advance value: the gNB 504 informs the UE 502 to change its timing so it can compensate for the round trip delay caused by the UE's distance from the gNB 504; and/or uplink grant resources: the gNB 504 may assign initial resources to the UE 502 so that it may use the UL-SCH.

In certain embodiments, for SI requests, the UE 502 may only need to receive an acknowledgement that the PRACH preamble 508 was detected by the gNB 504. In such embodiments, there may be no continuous UL-SCH transmission (e.g., message 3) in response to receipt of the SI request feedback message. Thus, in such embodiments, only the MAC PDU subheader of the RAR containing the PRACH preamble 508ID field identifying the received PRACH preamble 508 or the received PRACH preamble list is sent (e.g., there is no associated RAR message carrying the UL grant, T-CRNTI, TA, etc.).

In some embodiments, the SI request feedback may be sent within a RACH response message sent on the PDSCH (e.g., MAC PDU). In such embodiments, the feedback sent within the RACH response may be a list of PRACH preamble 508 IDs (e.g., identifying all SI request preambles received by the gNB), a bitmap, or another indication of requested SIBs provided by the gNB. In various embodiments, a new MAC CE may be introduced that contains a list of bitmaps or SIBs that the gNB received the request. In some embodiments, a reserved RA-RNTI value may be used (e.g., not calculated from the time/resources at which the preamble is sent). This reserved RA-RNTI may be specific to an on-demand SI request.

In various embodiments, UE 502 may send PRACH preamble 508 and read the minimum SI (e.g., SIB1) in order to check whether the gsb 504 will broadcast the requested SI (e.g., gsb 504 may flip the broadcast/non-broadcast indicator in response to the preamble being detected). In such embodiments, the UE 502 may re-trigger the SI request procedure (e.g., transmit the PRACH preamble 508) if the minimum SI does not indicate that the requested SI is broadcast. In such embodiments, the feedback is given by the minimum SI.

In various embodiments, scheduling information for transmission of the requested on-demand SI/SIB may be sent with the SI request feedback message. In such embodiments, the scheduling information may represent timing information when the UE 502 should monitor the requested SI on demand. In various embodiments, the scheduling information for the on-demand SI is provided by the minimum SI (e.g., in SIB1, including SIB type, validity information, periodicity, SI window information). In some embodiments, the gNB 504 may have more flexibility to transmit the requested SI when transmitting scheduling information for the requested on-demand SI along with the SI feedback message. In some embodiments, the requested SI may be sent at an earlier time instance than timing information provided by the smallest SI (e.g., reduced delay for acquiring system information). Also in embodiments that include scheduling information in the same message as the feedback message, the UE 502 does not need to read the minimum SI in order to acquire the latest (up-to-date) scheduling information for the on-demand SI. In one embodiment, the scheduling information of the requested SI is carried within a RAR message. In particular, in such embodiments, the MAC RAR is associated with a MAC PDU subheader having a random access preamble identification ("RAPID") (e.g., SI request feedback) identifying the transmitted PRACH preamble 508 and carrying scheduling information for on-demand SI for transmission requests. In embodiments where the feedback message includes scheduling information, the UE 502 may follow this scheduling information to receive the requested SI. In such embodiments, the scheduling information provided within the feedback message may take precedence over the scheduling information provided by the minimum SI. In various embodiments, when scheduling information for on-demand SI is always provided with feedback messages, there may be no need to broadcast the scheduling information within the minimum SI, which would save signaling overhead instead.

Fig. 6 is a schematic flow chart diagram illustrating one embodiment of a method 600 for receiving feedback for a system information request. In some embodiments, method 600 is performed by an apparatus, such as remote unit 102. In certain embodiments, the method 600 may be performed by a processor (e.g., a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.) executing program code.

The method 600 may include transmitting 602 information indicating a request for system information. The method 600 further includes monitoring 604 for a predetermined period of time indicating receipt of a feedback response to the request for system information.

In one embodiment, method 600 includes receiving scheduling information corresponding to system information. In another embodiment, method 600 includes receiving system information based on the scheduling information in response to receiving the feedback response. In some embodiments, method 600 includes, in response to not receiving a feedback response: retransmitting information indicating a request for system information; and monitoring for a feedback response indicating receipt of the request for system information during the predetermined time period. In various embodiments, retransmitting information indicative of a request for system information includes retransmitting information using increased power. In some embodiments, retransmitting the information indicative of the request for system information comprises retransmitting the information indicative of the request for system information up to a predetermined number of times.

In some embodiments, the feedback response is part of the downlink control information. In some embodiments, the radio network temporary identifier is used to indicate a feedback response. In various embodiments, the feedback response is indicated by one or more fields of the downlink control information being set to one or more predefined values. In one embodiment, the feedback response is part of a random access response message sent on a physical downlink shared channel. In some embodiments, the information indicating the request for system information comprises a physical random access channel preamble.

In some embodiments, the feedback response includes a physical random access channel preamble identifier corresponding to the physical random access channel preamble. In various embodiments, the information indicating the request for system information is part of a message 3 transmission during random access. In some embodiments, the information indicating the request for system information comprises a bitmap indicating the requested system information. In one embodiment, the feedback response includes information indicative of the requested system information. In some embodiments, the feedback response is part of a contention resolution message during random access. In various embodiments, the downlink scheduling information for the system information is sent with a feedback response.

Fig. 7 is a schematic flow chart diagram illustrating yet another embodiment of a method 700 for sending feedback for a system information request. In some embodiments, method 700 is performed by an apparatus, such as base unit 104. In certain embodiments, the method 700 may be performed by a processor (e.g., a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.) executing program code.

Method 700 may include receiving 702 information indicating a request for system information. The method 700 further includes sending 704 a feedback response indicating receipt of the request for system information.

In one embodiment, method 700 includes transmitting scheduling information corresponding to system information. In yet another embodiment, method 700 includes transmitting system information based on scheduling information.

In some embodiments, the feedback response includes a physical random access channel preamble identifier corresponding to the physical random access channel preamble. In various embodiments, the information indicating the request for system information is part of a message 3 transmission during random access. In some embodiments, the information indicating the request for system information comprises a bitmap indicating the requested system information. In one embodiment, the feedback response includes information indicative of the requested system information. In some embodiments, the feedback response is part of a contention resolution message during random access. In various embodiments, downlink scheduling information for system information is sent with a feedback response.

In some embodiments, the remote unit 102 may monitor for feedback messages sent from the base unit 104 while transmitting PRACH (e.g., SI request preamble). In various embodiments, the remote unit 102 may monitor the feedback message during a predetermined time period (e.g., a defined time period, time window, etc.). Further, in some embodiments, upon receiving the feedback message, the remote unit 102 may monitor the requested SI at the signaled SI window (e.g., as indicated in the scheduling information broadcast with the smallest SI). In some embodiments, in the absence of a feedback message, the remote unit 102 may assume that the base unit 104 does not detect a PRACH transmission and may retransmit the PRACH SI preamble. In such embodiments, the PRACH SI preamble may be retransmitted at an increased transmission power.

In one embodiment, the SI request feedback is sent within a RACH response message sent on PDSCH (e.g., MAC PDU). In some embodiments of the RACH procedure, the remote unit 102 monitors for a RACH response message (e.g., a PDCCH addressed to an RA-RNTI calculated from a slot in which the preamble was sent or used reserved/common RA-RNTI values — no RA-RNTI calculated from a slot in which the preamble was sent) when transmitting the PRACH SI preamble during the RACH response window.

Fig. 8 illustrates one embodiment of a MAC PDU 800. In some embodiments, the RACH response message is a MAC PDU 800, which includes a MAC PDU header 802 and a corresponding MAC RAR 804. In various embodiments, the MAC PDU header includes one or more MAC PDU subheaders, each subheader corresponding to a MAC RAR (except for the backoff indicator subheader). In certain embodiments, the MAC PDU subheader for the RAR contains a random access preamble ID 806 that identifies the transmitted random access preamble. In some embodiments, the MAC RAR 804 includes: timing advance command 808 (e.g., a timing advance value where base unit 104 can inform remote unit 102 to change its timing to compensate for a round trip delay caused by the distance of remote unit 102 from base unit 104), UL grant resource 810 (e.g., base unit 104 can assign an initial resource to remote unit 102 such that remote unit 102 can use UL-SCH), and/or temporary C-RNTI 812 (e.g., base unit 104 can give remote unit 102 another identifier for further communications).

In some embodiments, for SI requests, the remote unit 102 may only need to receive an acknowledgement that the PRACH SI preamble was detected and/or correctly received by the base unit 104. In various embodiments, there may not be a continuous UL-SCH transmission (e.g., message 3) in response to receiving the SI request feedback message. In such embodiments, the remote unit 102 may ignore the UL grant resource 810 field within the MAC RAR received in response to the SI request transmission (e.g., SI request feedback). In some embodiments, the remote unit 102 may not perform any uplink transmission in response to receiving the UL grant within the SI request feedback message (e.g., the remote unit 102 may process the UL grant and indicate it to lower layers such as the PHY). In various embodiments, the remote unit 102 may ignore the temporary C-RNTI 812 field and the timing advance command 808 field. In some embodiments, the remote unit 102 may not set the temporary C-RNTI to a value received in the RAR message (e.g., SI request feedback) and/or may not set the C-RNTI to a value of the temporary C-RNTI. In one embodiment, the remote unit 102 may not apply the timing advance command 808 received within the SI feedback message for the serving cell and/or the remote unit 102 may not start or restart a timer (e.g., timeAlignmentTimer) associated with the corresponding TAG. In some embodiments, the remote unit 102 may treat the random access procedure as successfully completed in response to receiving feedback (e.g., a random access response) for the SI request.

In some embodiments, the remote unit 102 may skip uplink transmissions scheduled by UL grant received within the SI request feedback message (e.g., RAR message). In various embodiments, the remote unit 102 skip feature is applied to UL grants received within RARs (e.g., SI request feedback messages). In such embodiments, the remote unit 102 may be enabled to skip UL transmissions in response to the remote unit 102 not having data for UL transmissions when requesting on-demand SI in idle mode or inactive mode. In some embodiments, the remote unit 102 may ignore the temporary C-RNTI 812 field and the timing advance command 808 field within the SI request feedback message (e.g., RAR).

In one embodiment, in response to receiving a RAR message (e.g., SI request feedback) containing UL grants, the remote unit 102 may perform UL transmissions accordingly. In some embodiments, the remote unit 102 may generate an SI request message that includes a list of SI/SIBs that the remote unit 102 is attempting to acquire. In such embodiments, the SI request message may be a MAC control element or RRC message. Further, the generated SI request message can be sent on the assigned UL resources (e.g., on UL grant resources 810 indicated in the UL grant). In various embodiments, the remote unit 102 applies a timing advance command 808 received in a RAR message (e.g., SI request feedback) for the serving cell/TAG and may use the indicated uplink timing (e.g., transmit SI request message) for the corresponding UL transmission. In some embodiments, the remote unit 102 may indicate (e.g., using fine granularity) which SI/SIB it wants to acquire by sending an SI request message in response to receiving an UL grant within the SI request feedback. This is particularly beneficial for the case where the PRACH preamble of the SI request is specific to the set of SI/SIBs.

Fig. 9 is a schematic flow chart diagram illustrating one embodiment of a method 900 for monitoring feedback responses acknowledging system information requests. In some embodiments, method 900 is performed by an apparatus, such as remote unit 102. In certain embodiments, the method 900 may be performed by a processor (e.g., a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.) executing program code.

Method 900 may include sending 902 information indicating a request for system information. In certain embodiments, method 900 includes monitoring 904 for a feedback response confirming receipt of the request for system information during a first predetermined time period. In some embodiments, method 900 includes indicating 906 successful completion of the random access procedure in response to receiving the feedback response.

In one embodiment, the feedback response is part of a random access response message sent on a physical downlink shared channel. In yet another embodiment, the information indicating the request for system information includes a physical random access channel preamble. In some embodiments, the feedback response includes a physical random access channel preamble identifier corresponding to the physical random access channel preamble. In various embodiments, a feedback response acknowledging receipt of the request for system information is sent in a medium access control subheader that includes a physical random channel preamble identifier. In some embodiments, method 900 includes, in response to not receiving a feedback response: retransmitting information indicating a request for system information; and during a second predetermined time period, monitoring for a feedback response confirming that the request for system information has been received.

In some embodiments, retransmitting information indicative of a request for system information comprises retransmitting information using increased power. In some embodiments, retransmitting the information indicating the request for system information includes repeatedly transmitting the information indicating the request for system information up to a predetermined number of times. In one embodiment, method 900 includes receiving scheduling information corresponding to system information. In some embodiments, method 900 includes, in response to receiving the feedback response, receiving system information based on the scheduling information.

In some embodiments, the feedback response is part of the downlink control information. In various embodiments, the radio network temporary identifier is used to indicate a feedback response. In some embodiments, method 900 includes not setting the cell radio network temporary identifier to a value in the feedback response. In one embodiment, the feedback response is indicated by one or more fields of the downlink control information being set to one or more predefined values. In some embodiments, the information indicating the request for system information is part of a message 3 transmission during random access. In various embodiments, the information indicating the request for system information comprises a bitmap indicating the requested system information. In some embodiments, the feedback response includes information indicative of the requested system information. In some embodiments, the feedback response is part of a contention resolution message during random access. In various embodiments, the downlink scheduling information for the system information is sent with a feedback response.

Fig. 10 is a schematic flow chart diagram illustrating one embodiment of a method 1000 for sending a feedback response to a remote unit 102 acknowledging receipt of a request for system information. In some embodiments, method 1000 is performed by an apparatus, such as base unit 104. In certain embodiments, the method 1000 may be performed by a processor (e.g., microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.) executing program code.

Method 1000 may include receiving 1002 information indicative of a request for system information from remote unit 102. In various embodiments, method 1000 includes sending 1004 a feedback response to remote unit 102 confirming that the request for system information has been received. In such embodiments, the remote unit 102 indicates that the remote access procedure was successfully completed in response to receiving the feedback response.

In one embodiment, method 1000 includes transmitting scheduling information corresponding to system information. In yet another embodiment, method 1000 includes transmitting system information based on scheduling information. In some embodiments, the feedback response is part of the downlink control information. In some embodiments, the radio network temporary identifier is used to indicate a feedback response. In various embodiments, the feedback response is indicated by one or more fields of the downlink control information being set to one or more predefined values. In one embodiment, the feedback response is part of a random access response message sent on a physical downlink shared channel. In some embodiments, the information indicating the request for system information comprises a physical random access channel preamble.

One embodiment includes a method comprising: transmitting information indicating a request for system information; monitoring for a feedback response confirming receipt of the request for system information during a first predetermined time period; and indicating successful completion of the random access procedure in response to receiving the feedback response.

In some embodiments, the feedback response is part of a random access response message sent on a physical downlink shared channel.

In various embodiments, the information indicating the request for system information comprises a physical random access channel preamble.

In some embodiments, the feedback response includes a physical random access channel preamble identifier corresponding to the physical random access channel preamble.

In one embodiment, a feedback response acknowledging receipt of the request for system information is sent in a medium access control subheader that includes a physical random channel preamble identifier.

In certain embodiments, a method further comprises: in response to not receiving the feedback response: retransmitting information indicating a request for system information; during a second predetermined time period, a feedback response acknowledging receipt of the request for system information is monitored.

In various embodiments, retransmitting information indicative of a request for system information includes retransmitting information using increased power.

In some embodiments, retransmitting the information indicating the request for system information includes repeatedly transmitting the information indicating the request for system information up to a predetermined number of times.

In one embodiment, a method includes receiving scheduling information corresponding to system information.

In certain embodiments, a method comprises: in response to receiving the feedback response, system information is received based on the scheduling information.

In various embodiments, the feedback response is part of the downlink control information.

In some embodiments, a radio network temporary identifier is used to indicate the feedback response.

In one embodiment, a method includes not setting a cell radio network temporary identifier to a value in a feedback response.

In some embodiments, the feedback response is indicated by one or more fields of the downlink control information being set to one or more predefined values.

In various embodiments, the information indicating the request for system information is part of a message 3 transmission during random access.

In some embodiments, the information indicating the request for system information comprises a bitmap indicating the requested system information.

In one embodiment, the feedback response includes information indicative of the requested system information.

In some embodiments, the feedback response is part of a contention resolution message during random access.

In various embodiments, the downlink scheduling information for the system information is sent with a feedback response.

An apparatus comprising: a transmitter that transmits information indicating a request for system information; a receiver monitoring a feedback response confirming receipt of the request for system information during a first predetermined time period; and a processor that indicates successful completion of the random access procedure in response to receiving the feedback response.

In some embodiments, in response to not receiving a feedback response: the transmitter retransmits information indicating a request for system information; and the receiver monitors for a feedback response confirming receipt of the request for system information during a second predetermined time period.

In various embodiments, the transmitter retransmits the information indicating the request for system information by retransmitting the information using increased power.

In some embodiments, the transmitter retransmits the information indicating the request for system information by repeatedly transmitting the information indicating the request for system information a predetermined number of times.

In one embodiment, a receiver receives scheduling information corresponding to system information.

In some embodiments, in response to receiving the feedback response, the receiver receives system information based on the scheduling information.

In one embodiment, the processor does not set the cell radio network temporary identifier to a value in the feedback response.

One method comprises the following steps: receiving information from a remote unit indicating a request for system information; and sending a feedback response to the remote unit acknowledging receipt of the request for system information, wherein the remote unit indicates successful completion of the remote access procedure in response to receiving the feedback response.

In some embodiments, a method includes transmitting scheduling information corresponding to system information.

In some embodiments, a method includes transmitting system information based on scheduling information.

In one embodiment, a radio network temporary identifier is used to indicate the feedback response.

In one embodiment, the feedback response includes a physical random access channel preamble identifier corresponding to the physical random access channel preamble.

In some embodiments, the feedback response is sent in a medium access control subheader that includes a physical random channel preamble identifier.

In some embodiments, the information indicating the request for system information is part of a message 3 transmission during random access.

In various embodiments, the information indicating the request for system information comprises a bitmap indicating the requested system information.

In some embodiments, the downlink scheduling information for the system information is sent using a feedback response.

An apparatus comprising: a receiver that receives information indicating a request for system information from a remote unit; a transmitter that transmits a feedback response to the remote unit acknowledging receipt of the request for system information, wherein the remote unit indicates successful completion of the remote access procedure in response to receiving the feedback response.

In some embodiments, the transmitter transmits scheduling information corresponding to the system information.

In some embodiments, the transmitter transmits system information based on the scheduling information.

In one embodiment, the information indicating the request for system information comprises a bitmap indicating the requested system information.

In some embodiments, the feedback response includes information indicative of the requested system information.

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

Claims

1. A method in a user equipment of a 3GPP system, comprising:

transmitting information indicating a request for system information, wherein the information indicating the request for the system information comprises a bitmap indicating the requested system information;

monitoring for a feedback response acknowledging receipt of the request for the system information during a first predetermined time period, wherein the feedback response is part of a contention resolution message during random access; and

indicating successful completion of a random access procedure in response to receiving the feedback response.

2. The method of claim 1, wherein the information indicative of the request for the system information comprises a physical random access channel preamble.

3. The method of claim 2, wherein the feedback response includes a physical random access channel preamble identifier corresponding to the physical random access channel preamble.

4. The method of claim 3, wherein the feedback response acknowledging receipt of the request for the system information is transmitted in a medium access control subheader comprising the physical random channel preamble identifier.

5. The method of claim 1, wherein a radio network temporary identifier is used to indicate the feedback response.

6. The method of claim 1, wherein the feedback response is indicated by one or more fields of downlink control information set to one or more predefined values.

7. The method of claim 1, wherein the information indicative of the request for the system information is part of a message 3 transmission during random access.

8. The method of claim 1, wherein the feedback response is utilized to transmit downlink scheduling information for the system information.

9. A user equipment of a 3GPP system, comprising:

a transmitter to transmit information indicating a request for system information, wherein the information indicating the request for the system information comprises a bitmap indicating the requested system information;

a receiver that monitors for a feedback response acknowledging receipt of the request for the system information during a first predetermined time period, wherein the feedback response is part of a contention resolution message during random access; and

a processor that indicates successful completion of a random access procedure in response to receiving the feedback response.

10. The user equipment of claim 9, wherein, in response to not receiving the feedback response:

the transmitter retransmitting the information indicating the request for the system information; and

the receiver monitors for the feedback response acknowledging receipt of the request for the system information during a second predetermined time period.

11. The user equipment of claim 10, wherein the transmitter retransmits the information indicative of the request for the system information by retransmitting the information using increased power.

12. The user equipment of claim 10, wherein the transmitter retransmits the information indicative of the request for the system information by repeatedly transmitting information indicative of the request for the system information a predetermined number of times.

13. The user equipment of claim 9, wherein the processor does not set a cell radio network temporary identifier to a value in the feedback response.

14. A base station of a 3GPP system, comprising:

a receiver to receive information indicating a request for system information from a remote unit, wherein the information indicating the request for the system information comprises a bitmap indicating the requested system information; and

a transmitter that sends a feedback response to the remote unit acknowledging receipt of the request for the system information, wherein the feedback response is part of a contention resolution message during random access, wherein the remote unit indicates successful completion of a remote access procedure in response to receiving the feedback response.