Solution to mismatch in random access radio network temporary identifier calculation

Abstract

A base station may operate in a situation where a propagation delay between the base station and a user equipment (UE) device is large. The base station configures a common delay to the UE device. The base station receives a random access preamble from the UE device. The base station determines a time slot in which the random access preamble is transmitted based on a configured correspondence between an allowable time slot and a subset of an available set of preambles. The base station calculates a random access radio network temporary identifier (RA-RNTI) based on a parameter value including an index of the determined time slot. The base station employs the calculated RA-RNTI to resolve a random access response to the UE device.

Description

[0001] Priority claim information

[0002] This application is a U.S. national phase application of international application PCT / CN2020 / 107125, entitled “Random Access Preamble Transmission Using a Timing-Based Partition of Preamble Space”, filed on August 5, 2020, which is hereby incorporated by reference in its entirety. The claims in this patent application are different from those in the parent application or other related applications. Therefore, the applicant withdraws any waiver of the scope of the claims made in the parent application or any previous application related to this application. Therefore, the examiner is advised that it may be necessary to re-examine any such prior waivers that have been avoided and the references cited. In addition, any waiver made in this application should not be deemed to be contained in the context of the parent application or other related applications or to be read with reference to the parent application or other related applications. Technical Field

[0003] The present disclosure relates to the field of wireless communications, and more particularly, to a mechanism that enables a base station to facilitate random access of a user equipment device when the propagation delay between the base station (or access node) and the user equipment device is large. Background Art

[0004] When the distance between a base station and a user equipment (UE) device is large (e.g., greater than a time slot duration (or subframe duration)), the ability of the UE device to successfully perform random access may be impaired. As part of the random access procedure, the UE device may calculate a random access radio network temporary identifier (RA-RNTI) based on an index of a time slot in which the UE device transmits a random access preamble. The base station may separately calculate the RA-RNTI based on an index of a time slot in which the preamble is received. In prior art networks, the two indexes are the same because the propagation delay between the UE device and the base station is substantially less than the time slot duration. Therefore, the separately calculated RA-RNTIs are equal. However, if the propagation delay between the UE device and the base station is large enough, the two time indexes will not be consistent, resulting in a mismatch between the separately calculated RA-RNTIs. Therefore, when the base station transmits a random access response (RAR) based on its RA-RNTI, the UE device will fail to identify the RAR because its process of monitoring RAR transmission is based on different RA-RNTIs. Therefore, a mechanism is needed that can resolve RA-RNTI mismatches in the case of a network with a large propagation delay (LPD) between the UE device and the base station. Summary of the invention

[0005] In one set of embodiments, a method for operating a base station may include one or more of the following. (The base station may be configured to operate when the propagation delay between the base station and the UE device is large (e.g., greater than the time slot duration, or greater than the radio frame duration)). The base station may receive a random access preamble from a user equipment (UE) device. The base station may determine the time slot in which the random access preamble is transmitted based on the configured correspondence between the allowable time slots and a subset of the available set of random access preambles. The base station may calculate a random access radio network temporary identifier (RA-RNTI) based on a parameter value including an index of the determined time slot. The base station may generate a random access response for the UE device in response to receiving the random access preamble. The base station may generate a physical downlink control channel (PDCCH), wherein the action of generating the PDCCH includes scrambling a cyclic redundancy checksum (CRC) of downlink control information (DCI) using the RA-RNTI. (The expression "scrambling the CRC" is meant to include scrambling the entire CRC, or scrambling only a subset of the CRC bits. The downlink control information may correspond to a random access response, for example, pointing to a PDSCH resource containing a random access response for the UE. The base station may transmit the PDCCH and the random access response, for example, as part of a subframe of a downlink signal. A UE device that has independently calculated the RA-RNTI may monitor the subframe of the downlink signal for a DCI whose CRC has been scrambled with the RA-RNTI.

[0006] In some embodiments, the method may further include transmitting a common delay value to UE devices in a cell coverage area of ​​the base station prior to receiving the random access preamble.

[0007] In some embodiments, the method may also include determining a differential round trip time (RTT) based on: (a) the time at which the random access preamble is received at the base station, and (b) the transmission time of the base station in a particular time slot whose time index coincides with the determined time slot.

[0008] In some embodiments, the method may further include transmitting an indication (e.g., an implicit indication) of a differential delay value to the UE device, wherein the differential delay value is half of the differential RTT. The UE device may use the differential delay value together with the common delay value to determine a total delay, and apply a timing advance based on the total delay, such as so that its uplink transmissions will arrive at the base station synchronously with the timing of the base station, and / or so that the reception of its downlink channels will be synchronized with the arrival of those channels at the UE device.

[0009] In some embodiments, the method may further include broadcasting system information (SI) including random access configuration information, wherein the random access configuration information includes a common delay value. The common delay value may be defined as a propagation delay between a base station and a reference point in a cell coverage area of ​​the base station. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A better understanding of the present subject matter may be obtained when the following detailed description of the preferred embodiments is considered in conjunction with the following drawings.

[0011] Figure 1 to Figure 2 An example of a wireless communication system according to some embodiments is shown.

[0012] Figure 3 An example of a base station in communication with a user equipment device is shown according to some embodiments.

[0013] Figure 4 An example of a block diagram of a user equipment device is shown according to some embodiments.

[0014] Figure 5 An example of a block diagram of a base station according to some embodiments is shown.

[0015] Figure 6 An example of user equipment 600 is shown according to some embodiments.

[0016] Figure 7 An example of a base station 700 according to some embodiments is shown. The base station 700 may be used to communicate with Figure 6 The user equipment 600 communicates with the user equipment 600.

[0017] Fig. 8A An example of an 8-slot differential round trip time between a user equipment and a base station is shown according to some embodiments.

[0018] Figure 8B An example of one user equipment having a differential round trip time of 8 slots versus another UE having a differential round trip time of less than one slot is shown in accordance with some embodiments.

[0019] Fig. 9 A sequence of messages exchanged between a user equipment and a base station during a random access procedure (RACH) according to some embodiments is shown.

[0020] Fig. 10A The structure of the RACH-ConfigCommon message according to 3GPP TS 38.331 is shown.

[0021] Fig. 10B The structure of the RACH-ConfigGeneric message according to 3GPP TS 38.331 is shown.

[0022] Fig. 10C The concept of differential delay according to some embodiments is shown.

[0023] Fig.11 A set of Physical Random Access Channel (PRACH) configurations according to 3GPP TS 38.211 is shown.

[0024] Fig.12 A method for operating a user equipment device according to some embodiments is shown. The method may enable the user equipment to perform random access with a base station in situations where the propagation delay between the user equipment and the base station is large.

[0025] Fig.13 A method for operating a base station according to some embodiments is shown. The method may enable the base station to support random access of user equipment devices in situations where the propagation delay between the base station and the user equipment is large.

[0026] Although the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and described in detail herein. However, it should be understood that the drawings and detailed description thereof are not intended to limit this document to the specific forms disclosed, but on the contrary, their purpose is to cover all modifications, equivalents and alternatives that fall within the spirit and scope of the subject matter as defined by the appended claims. DETAILED DESCRIPTION

[0027] Acronyms

[0028] The following acronyms are used in this disclosure:

[0029] 3GPP: Third Generation Partnership Project

[0030] 3GPP2: Third Generation Partnership Project 2

[0031] 5G NR: Fifth Generation New Radio

[0032] BW: Bandwidth

[0033] BWP: Bandwidth Part

[0034] CQI: Channel Quality Indicator

[0035] DCI: Downlink Control Information

[0036] DL: Downlink

[0037] DRX: Discontinuous Receive Cycle

[0038] eNB (or eNodeB): Evolved Node B, i.e., the base station of 3GPP LTE

[0039] gNB (or gNodeB): Next-generation Node B, i.e., the base station of 5G NR

[0040] GSM: Global System for Mobile Communications

[0041] HARQ: Hybrid ARQ

[0042] LTE: Long Term Evolution

[0043] LTE-A: LTE Advanced

[0044] MAC: Media Access Control

[0045] MAC-CE: MAC Control Element

[0046] NR: New Radio

[0047] NR-DC: NR Dual Connectivity

[0048] NW: Network

[0049] PRACH: Physical Random Access Channel

[0050] RA: Random Access

[0051] RACH: Random Access Channel

[0052] RAT: Radio Access Technology

[0053] RLC: Radio Link Control

[0054] RLF: Radio Link Failure

[0055] RLM: Radio Link Monitoring

[0056] RNTI: Radio Network Temporary Identifier

[0057] RRC: Radio Resource Control

[0058] RRM: Radio Resource Management

[0059] RS: Reference signal

[0060] SR: Scheduling Request

[0061] SSB: Synchronization Signal Block

[0062] UE: User Equipment

[0063] UL: Uplink

[0064] UMTS: Universal Mobile Telecommunications System

[0065] the term

[0066] The following is a glossary of terms used in this disclosure:

[0067] Memory medium - any of the various types of memory devices or storage devices. The term "memory medium" is intended to include installation media, such as CD-ROM, floppy disk, or tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media, for example, hard disk drives or optical storage devices; registers, or other similar types of memory elements, etc. The memory medium may also include other types of memory, or a combination thereof. In addition, the memory medium may be located in a first computer system executing a program, or may be located in a different second computer system connected to the first computer system via a network such as the Internet. In the latter case, the second computer system may provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory media that may reside in different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., in the form of a computer program) that may be executed by one or more processors.

[0068] Carrier Media—storage media as described above, and physical transmission media such as a bus, network, and / or other physical transmission media that transport signals such as electrical, electromagnetic, or digital signals.

[0069] Programmable hardware element - includes various hardware devices that include multiple programmable function blocks connected via programmable interconnects. Examples include FPGA (field programmable gate array), PLD (programmable logic device), FPOA (field programmable object array), and CPLD (complex PLD). Programmable function blocks can vary from fine-grained (combinational logic unit or lookup table) to coarse-grained (arithmetic logic unit or processor core). Programmable hardware elements may also be referred to as "configurable logic units".

[0070] Computer System—Any of various types of computing or processing systems, including a personal computer system (PC), a mainframe computer system, a workstation, a network appliance, an Internet appliance, a personal digital assistant (PDA), a personal communication device, a smart phone, a television system, a grid computing system, or other devices or combinations of devices. In general, the term "computer system" may be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0071] User Equipment (UE) (or "UE device") - any of various types of computer system devices that are mobile or portable and that perform wireless communications. Examples of UE devices include mobile phones or smart phones (e.g., iPhone TM , based on Android TM phones), portable gaming devices (e.g., Nintendo DS TM , PlayStation Portable TM 、Gameboy Advance TM , iPhone TM ), wearable devices (e.g., smart watches, smart glasses), laptops, PDAs, portable Internet devices, music players, data storage devices, or other handheld devices, etc. In general, the term "UE" or "UE device" can be broadly defined to include any electronic, computing, and / or telecommunication device (or combination of devices) that is easily transportable by a user and capable of wireless communication.

[0072] Base Station—The term “base station” has the full breadth of its ordinary meaning and includes at least a wireless communication station that is installed at a fixed location and used to communicate as part of a wireless telephone system or radio system.

[0073] Processing Element—refers to any of various elements or combinations of elements. Processing elements include, for example, circuits such as ASICs (application specific integrated circuits), portions or circuits of individual processor cores, entire processor cores, individual processors, programmable hardware devices such as field programmable gate arrays (FPGAs), and / or larger portions of systems including multiple processors.

[0074] Automatic—refers to an action or operation being performed by a computer system (e.g., software executed by a computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) without the need for the action or operation to be directly specified or performed by a user input. Thus, the term "automatic" is in contrast to a user manually performing or specifying an action, wherein the user provides input to directly perform the action. An automatic process may be initiated by input provided by a user, but subsequent actions performed "automatically" are not specified by the user, i.e., are not performed "manually," wherein the user specifies each action to be performed. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing in information, selecting checkboxes, radio selections, etc.) is manually filling out the form, even though the computer system must update the form in response to the user action. The form may be automatically filled out by a computer system, wherein the computer system (e.g., software executed on the computer system) analyzes the fields of the form and fills out the form without requiring any user input to specify the answers to the fields. As indicated above, a user may invoke automatic filling out of a form, but not participate in the actual filling out of the form (e.g., the user does not manually specify the answers to the fields but rather they are automatically completed). This specification provides various examples of operations that are automatically performed in response to actions taken by a user.

[0075] Figures 1 to 3 -Communication system

[0076] Figure 1 and Figure 2 An exemplary (and simplified) wireless communication system is shown. Note that Figure 1 and Figure 2 The systems are merely examples of some possible systems, and various embodiments may be implemented in any of a variety of ways as desired.

[0077] Figure 1 The wireless communication system of 102 includes a base station 102A that communicates with one or more user equipment (UE) devices 106A, 106B, etc. to 106N via a transmission medium. Each of the user equipment devices may be referred to herein as a "user equipment" (UE). Figure 2 In the wireless communication system, in addition to the base station 102A, the base station 102B also communicates with the UE devices 106A, 106B, etc. to 106N through the transmission medium (for example, simultaneously or concurrently).

[0078] Base stations 102A and 102B may be base transceiver stations (BTS) or cell sites, and may include hardware to enable wireless communications with user devices 106A through 106N. Each base station 102 may also be equipped to communicate with a core network 100 (e.g., base station 102A may be coupled to core network 100A, while base station 102B may be coupled to core network 100B), which may be a core network of a cellular service provider. Each core network 100 may also be coupled to one or more external networks (such as external network 108), which may include the Internet, a public switched telephone network (PSTN), or any other network. Thus, base station 102A may facilitate communications between user devices and / or between user devices and network 100A; in Figure 2 In a system, base station 102B may facilitate communications between user devices and / or between user devices and network 100B.

[0079] The base stations 102A and 102B and the user equipment may be configured to communicate via a transmission medium using any of a variety of radio access technologies (RATs), also referred to as wireless communication technologies or telecommunication standards, such as GSM, UMTS (WCDMA), LTE, Advanced LTE (LTE-A), 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, WiMAX, etc.

[0080] For example, base station 102A and core network 100A may operate according to a first cellular communication standard (e.g., LTE), while base station 102B and core network 100B may operate according to a second (e.g., different) cellular communication standard (e.g., GSM, UMTS, and / or one or more CDMA2000 cellular communication standards). The two networks may be controlled by the same network operator (e.g., cellular service provider or "operator") or different network operators. In addition, the two networks may operate independently of each other (e.g., if they operate according to different cellular communication standards), or may operate in a somewhat coupled or tightly coupled manner.

[0081] It should also be noted that although Figure 2The illustrated network configuration may use two different networks to support two different cellular communication technologies, but other network configurations implementing multiple cellular communication technologies are possible. As an example, base stations 102A and 102B may operate according to different cellular communication standards, but are coupled to the same core network. As another example, a multi-mode base station capable of simultaneously supporting different cellular communication technologies (e.g., LTE and CDMA 1xRTT, GSM and UMTS, or any other combination of cellular communication technologies) may be coupled to a core network that also supports different cellular communication technologies. Any other various network deployment scenarios are also possible.

[0082] As another possibility, base station 102A and base station 102B may also operate according to the same wireless communication technology (or a set of overlapping wireless communication technologies). For example, base station 102A and core network 100A may be operated by one cellular service provider independently of base station 102B and core network 100B, which may be operated by different (e.g., competing) cellular service providers. Thus, in this case, despite using similar and possibly compatible cellular communication technologies, UE devices 106A-106N may independently communicate with base stations 102A-102B, possibly by utilizing separate subscriber identities to communicate with different operator networks.

[0083] UE 106 can communicate using multiple wireless communication standards. For example, UE 106 can be configured to communicate using any one or two cellular communication standards in a 3GPP cellular communication standard (such as LTE) and / or a 3GPP2 cellular communication standard (such as a cellular communication standard in the CDMA2000 series of cellular communication standards). As another example, UE 106 can be configured to communicate using different 3GPP cellular communication standards (such as two or more of GSM, UMTS, LTE, or LTE-A). Therefore, as described above, UE 106 can be configured to communicate with base station 102A (and / or other base stations) according to a first cellular communication standard (e.g., LTE) and can also be configured to communicate with base station 102B (and / or other base stations) according to a second cellular communication standard (e.g., one or more CDMA2000 cellular communication standards UMTS, GSM, etc.).

[0084] Base stations 102A and 102B and other base stations operating according to the same or different cellular communication standards may thus be provided as one or more cell networks that can provide continuous or nearly continuous overlapping service to UEs 106A-106N and similar devices over a wide geographic area via one or more cellular communication standards.

[0085] The UE 106 may also or alternatively be configured to communicate using WLAN, Bluetooth, one or more global navigation satellite systems (GNSS, such as GPS or GLONASS), one and / or more mobile television broadcast standards (e.g., ATSC-M / H or DVB-H), etc. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0086] Figure 3 A user equipment 106 (e.g., one of devices 106A through 106N) is shown communicating with a base station 102 (e.g., one of base stations 102A or 102B). UE 106 may be a device with wireless network connectivity, such as a mobile phone, a handheld device, a computer or tablet, a wearable device, or substantially any type of wireless device.

[0087] The UE may include a processor configured to execute program instructions stored in a memory. The UE may perform any of the method implementations described herein by executing such stored instructions. Alternatively or in addition, the UE may include a programmable hardware element such as an FPGA (field programmable gate array) configured to perform any of the method implementations described herein, or any part of any of the method implementations described herein.

[0088] UE 106 may be configured to communicate using any of a number of wireless communication protocols. For example, UE 106 may be configured to communicate using two or more of GSM, UMTS (W-DCMA, TD-SCDMA, etc.), CDMA2000 (1xRTT, 1xEV-DO, HRPD, eHRPD, etc.), LTE, LTE-A, WLAN, or GNSS. Other combinations of wireless communication standards are also possible.

[0089] UE 106 may include one or more antennas for communicating using one or more wireless communication protocols. Within UE 106, one or more portions of the receive and / or transmit chains may be shared between multiple wireless communication standards; for example, UE 106 may be configured to communicate using a single shared radio using one (or both) of GSM or LTE. The shared radio may include a single antenna, or may include multiple antennas for performing wireless communication (e.g., for MIMO or beamforming). MIMO is an acronym for Multiple Input Multiple Output.

[0090] Figure 4 -UE Block Diagram Example

[0091] Figure 4An example of a block diagram of a UE 106 is shown. As shown, the UE 106 may include a system on chip (SOC) 300, which may include parts for various purposes. For example, as shown, the SOC 300 may include a processor 302 that can execute program instructions for the UE 106 and a display circuit 304 that can perform graphics processing and provide display signals to a display 345. The processor 302 may also be coupled to a memory management unit (MMU) 340 and / or other circuits or devices (such as display circuit 304, radio component 330, connector I / F 320 and / or display 345), which may be configured to receive addresses from the processor 302 and convert those addresses into locations in a memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310). The MMU 340 may be configured to perform memory protection and page table conversion or setup. In some embodiments, the MMU 340 may be included as part of the processor 302.

[0092] As shown, SOC 300 may be coupled to various other circuits of UE 106. For example, UE 106 may include various types of memory (e.g., including flash memory 310), a connector interface 320 (e.g., for coupling to a computer system, a docking station, a charging station, etc.), a display 345, and a radio 330.

[0093] The radio component 330 may include one or more RF chains. Each RF chain may include a transmission chain, a reception chain, or both. For example, the radio component 330 may include two RF chains to support dual connectivity with two base stations (or two cells). The radio component may be configured to support wireless communications according to one or more wireless communication standards (e.g., one or more of GSM, UMTS, LTE, LTE-A, WCDMA, CDMA2000, Bluetooth, Wi-Fi, GPS, etc.).

[0094] The radio component 330 is coupled to an antenna subsystem 335 including one or more antennas. For example, the antenna subsystem 335 may include multiple antennas to support applications such as dual connectivity or MIMO or beamforming. The antenna subsystem 335 transmits and receives radio signals to / from one or more base stations or devices through a radio propagation medium (usually the atmosphere).

[0095] In some embodiments, the processor 302 may include a baseband processor to generate uplink baseband signals and / or process downlink baseband signals. The processor 302 may be configured to perform data processing according to one or more wireless communication standards (e.g., one or more of GSM, UMTS, LTE, LTE-A, WCDMA, CDMA2000, Bluetooth, Wi-Fi, GPS, etc.).

[0096] The UE 106 may also include one or more user interface elements. The user interface elements may include various elements such as a display 345 (which may be a touch screen display), a keyboard (which may be a separate keyboard or may be implemented as part of the touch screen display), a mouse, a microphone and / or a speaker, one or more cameras, one or more sensors, one or more buttons, sliders and / or dials, and / or any of a variety of other elements capable of providing information to a user and / or receiving or interpreting user input.

[0097] As shown, the UE 106 may also include one or more user identity modules (SIMs) 360. Each of the one or more SIMs may be implemented as an embedded SIM (eSIM), in which case the SIM may be implemented in device hardware and / or software. For example, in some embodiments, the UE 106 may include an embedded UICC (eUICC), for example, a device that is built into the UE 106 and is not removable. The eUICC may be programmable so that one or more eSIMs may be implemented on the eUICC. In other embodiments, the eSIM may be installed in the UE 106 software, for example, as program instructions stored on a storage medium (such as memory 306 or Flash 310) executed on a processor (such as processor 302) in the UE 106. As an example, the SIM 360 may be an application executed on a universal integrated circuit card (UICC). Alternatively or in addition, one or more of the SIMs 360 may be implemented as a removable SIM card.

[0098] The processor 302 of the UE device 106 may be configured to implement some or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). In other embodiments, the processor 302 may be configured as or include: a programmable hardware element such as an FPGA (field programmable gate array); or an ASIC (application-specific integrated circuit); or a combination thereof.

[0099] Figure 5 - Base station example

[0100] Figure 5 1 shows a block diagram of a base station 102. Note that Figure 5 The base station of is only one example of a possible base station. As shown, the base station 102 may include a processor 404 that may execute program instructions for the base station 102. The processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuit or device, which may be configured to receive addresses from the processor 404 and convert these addresses to locations in memory (e.g., memory 460 and read-only memory (ROM) 450).

[0101] The base station 102 may include at least one network port 470. The network port 470 may be configured to couple to a telephone network and provide (to multiple devices such as the UE device 106) services such as those described above in Figure 1 and Figure 2 Access to the telephone network as described in.

[0102] The network port 470 (or an additional network port) may also or alternatively be configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to multiple devices, such as the UE device 106. In some cases, the network port 470 may be coupled to a telephone network via the core network, and / or the core network may provide a telephone network (e.g., in other UE devices served by the cellular service provider).

[0103] The base station 102 may include a radio component 430 having one or more RF chains. Each RF chain may include a transmit chain, a receive chain, or both. (For example, the base station 102 may include at least one RF chain per sector or cell.) The radio 430 is coupled to an antenna subsystem 434 including one or more antennas. For example, multiple antennas may be required to support applications such as MIMO or beamforming. The antenna subsystem 434 transmits and receives radio signals to / from the UE through a radio propagation medium (typically the atmosphere).

[0104] In some embodiments, processor 404 may include a baseband processor to generate downlink baseband signals and / or process uplink baseband signals. The baseband processor may be configured to operate according to one or more wireless telecommunication standards, including but not limited to GSM, LTE, WCDMA, CDMA2000, etc.

[0105] The processor 404 of the base station 102 may be configured to implement part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). In some embodiments, the processor 404 may include: a programmable hardware element, such as an FPGA (field programmable gate array); or an ASIC (application-specific integrated circuit); or a combination thereof.

[0106] In some embodiments, the wireless user equipment (UE) device 600 may be configured as follows: Figure 6 UE device 600 may include: a radio subsystem 605 for performing wireless communications; and a processing element 610, which is operatively coupled to the radio subsystem. (UE device 600 may also include any subset of the UE features described above, for example, in combination with Figures 1 to 4 . )

[0107] The radio subsystem 605 may include one or more RF chains, for example, as described above. Each RF chain may be configured to receive signals from a radio propagation channel and / or transmit these signals to a radio propagation channel. Therefore, each RF chain may include a transmission chain and / or a reception chain. The radio subsystem 605 may be coupled to one or more antennas (or one or more antenna arrays) to facilitate signal transmission and reception. Each RF chain (or some RF chains) may be tuned to a desired frequency, thereby allowing the RF chain to receive or transmit at different frequencies at different times.

[0108] Processing element 610 may be coupled to the radio subsystem and may be configured as variously described above. (For example, the processing element may be implemented by processor 302.) The processing element may be configured to control the state of each RF chain in the radio subsystem.

[0109] In some embodiments, the processing element may include one or more baseband processors to (a) generate baseband signals to be transmitted by the radio subsystem and / or (b) process baseband signals provided by the radio subsystem.

[0110] In a dual-connection operating mode, the processing element may instruct the first RF chain to communicate with the first base station using the first radio access technology, and instruct the second RF chain to communicate with the second base station using the second radio access technology. For example, the first RF chain may communicate with an LTE eNB, and the second RF chain may communicate with a gNB of a 5G New Radio (NR). A link with an LTE eNB may be referred to as an LTE branch. A link with a gNB may be referred to as an NR branch. In some embodiments, the processing element may include a first subcircuit that implements baseband processing relative to the LTE branch and a second subcircuit that implements baseband processing relative to the NR branch.

[0111] Processing element 610 may be further configured as variously described in the following sections.

[0112] In some embodiments, a wireless base station 700 of a wireless network (not shown) may be configured as follows: Figure 7 The wireless base station may include: a radio subsystem 705 for performing wireless communications over a radio propagation channel; and a processing element 710, which is operatively coupled to the radio subsystem. (The wireless base station may also include any subset of the above-mentioned base station features, for example, the above-mentioned combination Figure 5 The characteristics described.)

[0113] The radio subsystem 710 may include one or more RF chains. Each RF chain may be tuned to a desired frequency, thereby allowing the RF chain to receive or transmit at different frequencies at different times. The radio subsystem 710 may be coupled to an antenna subsystem that includes one or more antennas, such as an antenna array or multiple antenna arrays. The radio subsystem may employ the antenna subsystem to transmit radio signals to and receive radio signals from a radio wave propagation medium.

[0114] Processing element 710 may be implemented as described in various ways above. For example, in one embodiment, processing element 710 may be implemented by processor 404. In some embodiments, the processing element may include one or more baseband processors to: (a) generate baseband signals to be transmitted by the radio subsystem, and / or (b) process baseband signals provided by the radio subsystem.

[0115] Processing element 710 may be configured to perform any of the base station method implementations described herein.

[0116] Solution for Random Access Radio Network Temporary Identifier (RA-RNTI) Mismatch

[0117] As various network technologies integrate with more traditional cellular network technologies, new network characteristics may emerge. As one example, the introduction of a new class of cellular base stations may introduce significantly larger and significantly more variable propagation delays than those associated with more traditional base stations.

[0118] For example, 3GPP has been involved in a number of research projects on integrating non-terrestrial networks (NTNs) into the 3GPP ecosystem. For example, see 3GPP TR 38.811, 3GPP TR 22.822, 3GPP work item 860046 (sNR_NTN_solutions). In such systems, the propagation delay between a UE such as UE 106 and a non-terrestrial network may be much greater than the propagation delay between the UE and a traditional terrestrial base station. In addition, such systems may include cells covering a larger geographic area than a traditional cell, which may result in a large difference in propagation delay between two points in the cell. In other words, in such systems, a UE at a first point in a cell may experience significantly greater propagation delay than a UE at a second point in the same cell.

[0119] A network in which the propagation delay between a base station and a user equipment (UE) device is large (e.g., large compared to a time slot duration, or large compared to a radio frame duration) may be referred to as a large propagation delay (LPD) network. For example, a base station may have a powerful transmitter and / or a sensitive receiver, and therefore have a large cell coverage area. As another example, a base station may be located on one continent, while a UE device is located on another continent. As yet another example, a base station may be located on a satellite (or airborne vehicle), while a UE device is located in the earth coverage area of ​​a beam of the base station, e.g., as in the case of a non-terrestrial network.

[0120] When the propagation delay between the base station and the user equipment (UE) device is large, the network may determine the common delay based on the distance between the base station and the reference point in the coverage area of ​​the base station. (The coverage area may correspond to an area where the intensity of the transmission beam generated by the base station is greater than a threshold.) The common delay may be defined as the propagation delay between the base station and the reference point. The common delay value may be signaled to the UEs in the coverage area via a system information broadcast (e.g., in a system information block (SIB) such as SIB1 or SIB2). Each UE device receives the system information broadcast and recovers the common delay value from the system information broadcast. Each UE device may apply a timing advance to its transmission and / or reception processing based on the common delay value. The timing advance may be equal to twice the common delay value.

[0121] A network element (such as a base station or a UE device or a core network node) may calculate a differential delay associated with the UE device, where the differential delay is the difference between (a) the propagation delay between the base station and the UE device and (b) the propagation delay between the base station and the reference point. (In some embodiments, the differential delay may be interpreted as the propagation delay that would occur if the base station were located at the reference point.) Thus, the propagation delay between the base station and the UE device (which may be referred to as the full (or total) delay) is the sum of the common delay and the differential delay.

[0122] In a network with a large propagation delay (LPD) between the base station and the UE device, the cell size may be equally large. Therefore, the differential delay may have an impact on basic procedures such as random access. For example, the differential delay may vary significantly between UE devices within a cell: those UE devices in a "near cell" (e.g., relatively closer to the base station) will have smaller differential delay values ​​than those in a "far cell" (e.g., relatively farther away from the base station). Therefore, RACH contention may favor those UE devices in the near cell over those in the far cell.

[0123] Fig. 8AAn example of an 8-slot differential round trip time (RTT) between a user equipment (UE) and a base station (e.g., a gNB for 3GPP NR) is shown in accordance with some embodiments. Three timelines are shown: one for the gNB downlink, one for the UE, and one for the gNB uplink. The UE may transmit a random access preamble in what it perceives as slot 0 (e.g., after applying a timing advance equal to twice the common delay). Since the UE has not yet compensated for the unknown differential delay (which is shown to be 4 slots in length), the UE's transmission corresponds to slot 4 of the gNB downlink timing. The random access preamble is received at a time slot with slot index t_id=8. Therefore, the UE will use t_id equal to 0 for its RA-RNTI calculation, while the base station will use t_id equal to 8 for its RA-RNTI calculation. This is how the mismatch in RA-RNTI occurs.

[0124] Figure 8B An example of an 8-slot differential round trip time versus a differential round trip time of less than one slot is shown in accordance with some embodiments. UE1 is in a far cell condition (e.g., far from a reference point) and has a one-way differential delay D1 of four slots. UE2 is in a near cell condition (e.g., close to a reference point) and has a one-way differential delay D2 of less than one slot. UE1's preamble transmission (which it perceives as slot 0) arrives at gNB in ​​slot 8. UE2's preamble transmission (which it perceives as slot 0) arrives at gNB in ​​slot 0. This situation illustrates a violation of the desired specification of having a unique RNTI in a single radio frame. The gNB can calculate the correct RA-RNTI value for UE2, but the value for UE1 is incorrect. Therefore, without resolving the issue of RA-RNTI mismatch, UEs far from the reference point may experience random access failures, while UEs close to the reference point may experience successful random access. This imbalance in network performance is undesirable.

[0125] RA-RNTI calculation

[0126] A random access radio network temporary identifier (RA-RNTI) is used during a random access procedure, e.g. Fig. 9 As shown. The MAC of the base station generates a random access response (RAR) as a response to the random access preamble transmitted by the UE. The RAR is transmitted on the DL-SCH transport. (MAC is an acronym for Medium Access Control.) In some embodiments, the base station can be, for example, a gNB of 3GPP NR.

[0127] The base station scrambles the cyclic redundancy checksum (CRC) of the PDCCH with the RA-RNTI for transmission of the PDSCH carrying the RAR. The RA-RNTI may be addressed to multiple UEs, for example, multiple UEs may decode the PDCCH scrambled with the same RA-RNTI.

[0128] The RA-RNTI associated with the physical random access channel (PRACH) that transmits the random access preamble can be calculated as follows:

[0129] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id.

[0130] Table: RA-RNTI calculation variables

[0131]

[0132]

[0133] More generally, RA-RNTI may be calculated based on a function (eg, a linear function) of the variables s_id, t_id, f_id, and ul_carrier_id, or any subset of these parameters. In some embodiments, the set of variables may be extended to include one or more variables in addition to those given here.

[0134] As from Fig. 8A As can be seen from the example, the value of t_id used by the UE (4) is different from the t_id used by the gNB (8). This mismatch will cause the RAR message to fail. In some embodiments, t_id is defined only for a single radio frame (e.g., a single radio frame of 10ms).

[0135] Therefore, a mechanism is needed to enable a large propagation delay (LPD) network to use the existing subframe number of the random access channel (RACH) RA-RNTI to infer the UE transmission of the preamble. In addition, fairness needs to be ensured when two UEs are in different cell conditions (or the same cell conditions) and have different differential delays in terms of the RACH procedure.

[0136] In response to receiving the random access response, the UE may transmit a third message (MSG3) of the random access procedure. The third message may be transmitted using resources and / or transmission parameters indicated in the random access response.

[0137] In response to receiving the third message, the base station may transmit a fourth message (MSG4) of the random access procedure. The content of the third message and the fourth message may depend on the purpose for which the UE initiates the random access procedure. Random access may be initiated for any of a variety of purposes, such as: initial access from an idle state; re-establishment of an RRC connection; handover (contention-based or non-contention-based); uplink data arrival during an RRC connected state; when timing advance is required. (RRC is an acronym for Radio Resource Control.)

[0138] Implicit indication of time slots used by user equipment

[0139] In some embodiments, the time slot used by the user equipment (UE) may be implicitly indicated to the base station. This implicit mechanism does not require any changes to the RA-RNTI calculation or the RA-RNTI space (i.e., the number of RNTIs). Note that if we extend t_id, the number of RA-RNTIs will increase.

[0140] In some embodiments, the UE and / or base station (e.g., gNB) may employ common compensation for round-trip time (RTT) or common compensation for one-way propagation delay.

[0141] The base station may broadcast a common delay value in SIB1 or SIB2 (ie, system information block #2) that compensates for most of the RTTs, for example, so that the differential delay is less than the frame length. The UE may consider the common delay when starting various procedures.

[0142] In some embodiments, the remaining delay (after compensation) is the differential delay. The differential delay varies with different locations of the UE within the cell.

[0143] According to 3GPP Technical Report 38.821, the differential one-way delay between gNB and UE is assumed to be approximately 3ms. However, it should be understood that different assumptions may be made in different implementations.

[0144] In some embodiments, the space of preambles may be divided into separate groups, and each group is assigned to a corresponding time slot. This concept can be summarized as "grouping preambles by time slot". In a random access (RACH) configuration, in any given time slot, only a subset of preambles may be used. Thus, when the base station detects the preamble, it knows which time slot is used by the UE for RACH preamble transmission. This time slot index can be used for RA-RNTI calculation.

[0145] In some embodiments, the configuration of physical random access channel (PRACH) transmission parameters may be based on: PRACH preamble format; time resources; frequency resources; and parameters for determining root sequences and their cyclic shifts. The parameters for determining root sequences and their cyclic shifts may include: an index to a logical root sequence table; a cyclic shift (Ncs); and a set type (unrestricted vs. restricted).

[0146] Based on these PRACH transmission parameters (or a subset thereof), the UE may generate an available set of random access preambles for a physical random access channel (PRACH) (e.g., a set of 64 preambles in one embodiment) and will randomly select one of the random access preambles for PRACH transmission.

[0147] In some embodiments, SIB1 or SIB2 (System Information Block #2) may be a modified version of SIB1 / SIB2 defined in 3GPP Technical Specification 38.331. For example, a new RACH Information Element (IE) may be added to the RACH-ConfigCommon structure to indicate a common delay offset. For example, "ra-CommonDelayOffset INTEGER (1..range)" may be added to Fig. 10A In the RACH-Configuration Common shown. Fig. 10B The RACH ConfigGeneric structure according to 3GPP TS 38.331 is shown.

[0148] In some embodiments, the mapping from logical index i to sequence number u may be as defined in 3GPP Technical Specification 38.211, for example, as defined in Table 6.3.3.1-3 of that specification. However, it should be noted that a variety of other mappings may be used in other embodiments.

[0149] The PRACH configuration index may also specify a set of time resources allowed for PRACH transmission, eg, a set of subframe numbers.

[0150] Fig. 10C The concept of differential delay according to some embodiments is shown. First, the common delay D common It is defined as the delay between a base station (BS) and a reference point in the cell coverage area of ​​the base station. The delay D between a base station and a user equipment (UE) BS,UE Depends on the location of the UE within the cell coverage area. The differential delay ΔD is defined as D BS,UE and D common The difference between: ΔD = D BS,UE -D common Note that no equipment is required to be located at the reference point.

[0151] In some embodiments, the reference point may be represented by a set of spatial coordinates in a memory of the base station or a memory of the core network node. The base station and / or the core network node may use the spatial coordinates of the reference point and the spatial coordinates of the base station to calculate the common delay.

[0152] Fig.11 A set of physical random access channel (PRACH) configurations as defined in 3GPP TS 38.211 is shown. Each configuration may have a PRACH configuration index, preamble format, x, y, subframe number, start symbol, number of PRACH slots within a subframe, number of time domain PRACH opportunities within a PRACH slot And PRACH duration It should be understood that the set of PRACH configurations and their indexes may be defined differently in different implementations.

[0153] In some implementations, the set of preambles may be equally (or approximately equally) divided among the available subframes of the PRACH configuration. For example, if the configuration index is 19, the first 32 preambles for PRACH may be transmitted in subframe 1, and the remaining 32 preambles may be transmitted in subframe 6. As another example, if the configuration index is 22, 21, 21, and 22 preambles may be allocated to slots 1, 4, and 7, respectively.

[0154] In some embodiments, additional columns may be added to Fig.11 to specify which preambles are sent in which subframes.

[0155] In some embodiments, for UEs operating with large propagation delays, a new PRACH configuration index value (e.g., a value equal to 33) may be added to Fig.11 The subframe number field for the new configuration may include a plurality of different subframe numbers n1, n2, ..., nL, where L>1. For simplicity, the subframe numbers n1, n2, ..., nL are represented by the subframe numbers n1, n2, ..., nL. L The subframes may be organized in ascending order, and each subframe number may be greater than or equal to zero and less than or equal to the maximum subframe number n. Max :

[0156] 0≤n1 <n2<…<n L ≤n Max .

[0157] Typical examples of the newly configured subframe number field include {0,3,6}, {1,4,7}, {0,2,7}, {0,4}, {2,7}, {1,8}, {0,2,4,6}, {1,4,7,8}, to name a few. When the UE receives the new PRACH configuration index value, it may transmit a random access preamble in a time slot determined according to the above preamble space partitioning among the configured subframe numbers (or time slots). The UE may select one of the configured subframe numbers to transmit its random access preamble.

[0158] Through this implicit mechanism, based on the detected preamble, the base station can determine which time resource is used for preamble transmission and then determine the time slot index t_id to be used for calculation of RA-RNTI.

[0159] In some embodiments, as a further extension, the subframes used by UE devices in the LPD network may be restricted. For example, such devices may be restricted to transmitting random access preambles only in a single subframe. In some embodiments, the base station may transmit a configuration message (e.g., an RRC message) that restricts the UE device to a random access (RACH) configuration indicating only one subframe. In other embodiments, the wireless communication standard may define that UE devices operating in the case of large propagation delays to / from a base station (e.g., a base station in a non-terrestrial network) will use a default configuration that restricts the UE device to a single subframe for preamble transmission. Therefore, a UE device operating on the default configuration may be restricted to a single subframe and not receive a random access configuration message.

[0160] In one set of embodiments, a method 1200 for operating a user equipment (UE) device may include: Fig.12 One or more of the operations shown. (The method 1200 may also include any subset of the above features, elements, and embodiments.) The method may be performed by a processing circuit of a UE device (e.g., by a processing element 610 of the user equipment 600). The UE device may be configured to communicate with an LPD network, wherein the propagation delay between the UE and a base station of the LPD network is large, for example, greater than a time slot duration, or greater than a radio frame duration.

[0161] At 1210, the processing circuit may select (eg, randomly select) a random access preamble from an available set of random access preambles. Processes for randomly selecting and for generating the selected random access preamble are known in the art of wireless communications.

[0162] At 1215, the processing circuit may select a time slot for transmitting the random access preamble based on a configured (or predetermined) correspondence between the allowable time slots and the subset of the available set. The correspondence (or mapping) between the allowable time slots and the subset of the available set may be indicated by configuration information provided by the base station. For example, the base station may transmit a physical random access channel (PRACH) configuration index indicating the allowable time slots and the corresponding one. The processing circuit may determine to which subset the selected random access preamble belongs and select a time slot corresponding to the subset.

[0163] At 1220, the processing circuit may transmit a random access preamble to the base station in the selected time slot. Figure 6 As described, the processing circuitry may perform transmission operations and reception operations using the radio subsystem 605. For example, the processing may transmit the random access preamble by supplying the random access preamble to the radio subsystem and instructing the radio subsystem to transmit the random access preamble.

[0164] At 1225, the processing circuit may calculate a random access radio network temporary identifier (RA-RNTI) based on the parameter values ​​including the index of the selected time slot. As described above, the RA-RNTI may be calculated.

[0165] At 1230, the processing circuit may receive (or detect) a random access response using the calculated RA-RNTI.

[0166] In some embodiments, prior to transmitting the random access preamble, the processing circuit may receive an indication of a common delay from the base station. (The common delay may be defined as a propagation delay between a base station and a reference point in a cell coverage area of ​​the base station. The indication of the common delay may be received as part of system information, e.g., as described variously above.) The random access preamble may be transmitted with a timing advance based on the common delay (e.g., equal to twice the common delay).

[0167] In some embodiments, the indication of the common delay may be received from a base station as part of system information, eg, as variously described above.

[0168] In some embodiments, method 1200 may also include considering common delays when starting one or more processes.

[0169] In some embodiments, after transmitting the random access preamble, the processing circuit may receive an indication of a differential delay value from the base station. The processing circuit may add the differential delay value to the common delay to obtain a total delay value. The processing circuit may apply a timing advance to the transmission and / or reception timing of the UE device, wherein the timing advance is based on the total delay value (e.g., equal to twice the total delay value).

[0170] In some embodiments, prior to the act of selecting a time slot, the processing circuit may receive an indication of a preamble configuration from the base station. The preamble configuration may indicate allowable time slots and a correspondence between allowable time slots and a subset of an available set of random access preambles.

[0171] In some embodiments, the uncompensated round-trip propagation time between the base station and the UE device is greater than the radio frame duration.

[0172] In some implementations, the random access preambles in the available set may be evenly partitioned among the subsets, eg, as variously described above.

[0173] In some embodiments, the base station may be a gNB compliant with the 3GPP New Radio standard, or an eNB compliant with the 3GPP Long Term Evolution standard.

[0174] In one set of embodiments, a method 1300 for operating a base station may include: Fig.13 One or more of the operations shown. (The method 1300 may also include any subset of the above features, elements, or operations.) The method may be performed by a processing circuit of a base station (e.g., by a processing element 710 of the base station 700). The base station may operate in (or be part of) a large propagation delay (LPD) network, where the propagation delay between the base station and the UE device is large, for example, greater than a time slot duration or greater than a radio frame duration.

[0175] At 1310, the processing circuit may receive a random access preamble from a user equipment (UE) device. For example, the processing circuit performs a correlation calculation to compare the received signal with a random access preamble in an available set of random access preambles. When one of the correlations produces a strong correlation peak (e.g., greater than a threshold), the processing circuit may identify that the corresponding preamble is present in the received signal. The location of the correlation peak may indicate the time of occurrence of the preamble in the received signal.

[0176] At 1315, the processing circuit may determine a time slot in which the random access preamble is transmitted by the UE device. The determination of the time slot may be based on a configured (or predetermined) correspondence between an allowable time slot and a subset of an available set of random access preambles. (Assuming that the UE device has transmitted the random access preamble in a time slot that complies with the correspondence between the allowable time slot and the subset, as described differently above.) For example, the processing circuit may determine which subset the random access preamble belongs to, and identify the time slot corresponding to the subset as the time slot in which the preamble is transmitted.

[0177] At 1320, the processing circuit may calculate a random access radio network temporary identifier (RA-RNTI) based on parameter values ​​including the index of the determined time slot, eg, as variously described above.

[0178] At 1325, the processing circuit may generate a random access response for the UE device in response to receiving the random access preamble. In some embodiments, the content of the random access response may be consistent with an existing wireless communication standard such as 3GPP Long Term Evolution (LTE) of 3GPP New Radio (NR).

[0179] At 1330, the processing circuit may generate a physical downlink control channel (PDCCH), wherein the act of generating the PDCCH includes scrambling a cyclic redundancy checksum (CRC) of downlink control information (DCI) using the RA-RNTI. (The expression "scrambling the CRC" is meant to include scrambling the entire CRC, or scrambling only a subset of the CRC bits.) The downlink control information may correspond to a random access response, e.g., pointing to a physical downlink shared channel (PDSCH) resource containing a random access response for the UE.

[0180] At 1335, the processing circuitry may transmit the PDCCH and random access response, for example, as part of a subframe of a downlink signal. A UE device that has independently calculated the RA-RNTI may monitor the subframe of the downlink signal for any DCI whose CRC has been scrambled with the RA-RNTI.

[0181] In some embodiments, method 1300 may also include: transmitting an indication of the common delay value to UE devices in the cell coverage area of ​​the base station before receiving the random access preamble. Each UE device may receive the indication and apply the timing advance to its transmission and / or reception processing. The timing advance may be based on the common delay value (e.g., equal to twice the common delay value).

[0182] In some embodiments, method 1300 may include determining a differential round trip time (RTT) based on: (a) a time slot determined based on a received random access preamble and a correspondence between a time slot and a preamble subset; (b) a time slot in which the random access preamble is received at a base station, and (d) a common delay.

[0183] In other embodiments, method 1300 may include determining a differential round trip time (RTT) based on: (a) a time at which a random access preamble is received at a base station, and (b) a transmission time of the base station in a particular time slot whose time index coincides with the determined time slot. Due to a common delay-based timing advance of the UE device, the particular time slot is unique because it occurs before time (a) and within one frame duration of time (a).

[0184] In some embodiments, method 1300 may also include transmitting an indication of a differential delay value to the UE device, wherein the differential delay value is half of the differential RTT. The UE device may use the differential delay value together with the common delay value to determine a total delay, and apply a timing advance based on the total delay, such as so that its uplink transmissions will arrive at the base station synchronously with the timing of the base station, and / or so that its reception of downlink channels from the base station will be synchronized with the arrival of those units at the UE device.

[0185] In some embodiments, method 1300 may further include broadcasting system information (SI) including random access configuration information, wherein the random access configuration information includes a common delay value, e.g., as described above in various ways. The common delay value may be defined as a propagation delay between a base station and a reference point in a cell coverage area of ​​the base station.

[0186] In some embodiments, the processing circuit may transmit an indication of a preamble configuration. The preamble configuration may indicate (a) allowable time slots and (b) a correspondence between allowable time slots and a subset of an available set of random access preambles. The UE device employs this information when selecting a time slot for transmitting a random access preamble.

[0187] In some embodiments, the uncompensated round-trip propagation time between the base station and the UE device is greater than the radio frame duration.

[0188] In some implementations, the random access preambles in the available set may be evenly divided among the subsets, eg, as variously described above.

[0189] In some embodiments, the base station may be a gNB compliant with the 3GPP New Radio standard, or an eNB compliant with the 3GPP Long Term Evolution standard.

[0190] In one set of embodiments, a method for operating a base station may include one or more of the following operations. The method may include receiving a random access preamble. The method may include determining a time index for the random access preamble based on grouping the random access preamble according to each time slot (or other time unit). The method may include calculating a random access radio network temporary identifier (RA-RNTI) based on the determined time index. The method may include: generating a random access response message in response to receiving the random access preamble, wherein the random access response message includes a physical downlink control channel (PDCCH), wherein a cyclic redundancy checksum (CRC) of the PDCCH is scrambled with the RA-RNTI. The method may include transmitting the random access response message. The method may also include the above in combination with Figures 1 to 13 Any subset of the features, elements, and operations described above. In one set of embodiments, a method for operating a user equipment (UE) may include: selecting a random access preamble from an allowable set of random access preambles; and transmitting the random access preamble in a specific time slot according to a random access preamble configuration, in which different time slots are allocated to different subsets of the allowable set of random access preambles. The method may also include the above in combination with Figures 1 to 13 Any subset of the features, elements and operations described.

[0191] In one set of embodiments, a method for operating a base station may include: receiving a random access preamble from an uplink signal; and determining a time index for calculating a random access radio network temporary identifier (RA-RNTI) based on a random access preamble configuration, in which different time slots are allocated to different subsets of an allowable set of random access preambles. The method may also include the above in combination Figures 1 to 13 Any subset of the features, elements and operations described.

[0192] In one set of embodiments, a method for operating a base station may include one or more of the following operations. The method may include: receiving a random access preamble transmitted by a UE as part of a random access procedure. The method may include determining a time index of a time slot for detecting a random access preamble (or an index of a time unit used by the UE to transmit a preamble). The method may include using the time index to calculate an RA-RNTI. The method may include: transmitting a random access response message in response to receiving a random access preamble, wherein the random access response message includes a physical downlink control channel (PDCCH), wherein a cyclic redundancy checksum (CRC) of the PDCCH is scrambled with the RA-RNTI. The method may also include the above in combination with Figures 1 to 13 Any subset of the features, elements and operations described.

[0193] In one set of embodiments, a method for operating a user equipment (UE) may include: generating N for random access P A set of preambles; and randomly select N P A preamble code is used for transmission to a base station, wherein the transmission parameters used for transmission are based on any subset of the following: physical random access channel (PRACH) preamble code format; time resources; frequency resources; parameters for determining a root sequence and its cyclic shift. The method may also include the above combined Figures 1 to 13 Any subset of the features, elements, and operations described. In some embodiments, the parameters used to determine the root sequence and its cyclic shift include: an index into a logical root sequence table; a cyclic shift value; and a set type (unrestricted vs. restricted).

[0194] In one set of embodiments, a method for operating a base station may include transmitting a physical random access channel (PRACH) configuration index to one or more user equipment (UE) devices, wherein the PRACH configuration index indicates a time resource (or a set of time resources) to be used by the one or more UE devices for PRACH transmission. The method may also include the above in combination Figures 1 to 13 Any subset of the described features, elements, and operations. In some embodiments, a PRACH configuration index indicates a subframe number (or a set of subframe numbers) to be used by one or more UE devices for PRACH transmission.

[0195] In one set of embodiments, a method for operating a user equipment (UE) may include: transmitting a selected physical random access channel (PRACH) preamble in a subframe according to a PRACH configuration, in which a set of possible preambles is partitioned (or divided) among two or more allowable subframes, wherein the two or more allowable subframes have been indicated to the UE in a PRACH configuration index. The method may also include the above in combination with Figures 1 to 13 Any subset of the features, elements and operations described.

[0196] In one set of embodiments, a method for operating a base station may include one or more of the following operations. The method may include receiving a PRACH preamble. The method may include determining a time index of a subframe in which a user equipment (UE) transmits a PRACH preamble based on which of a plurality of disjoint subsets of an allowable set of PRACH preambles the received PRACH preamble belongs. The method may include calculating a RA-RNTI based on the determined time index. The method may also include the above in combination with Figures 1 to 13 Any subset of the features, elements and operations described.

[0197] In one set of embodiments, a method for operating a user equipment (UE) in a large propagation delay (LPD) network may include: receiving a configuration for random access from a base station, wherein the configuration limits the transmission of a random access preamble to a single predetermined subframe; and transmitting the random access preamble in the single predetermined subframe. The method may also include the above in combination Figures 1 to 13 Any subset of the features, elements and operations described.

[0198] In one set of embodiments, a method for operating a base station may include one or more of the following operations. The method may include transmitting a configuration for random access to one or more user equipment (UE) devices, wherein the configuration limits the transmission of a random access preamble to a single predetermined subframe. The method may include receiving a random access preamble from a user equipment (UE) device. The method may include setting a time index to a value corresponding to a single predetermined subframe. The method may include calculating an RA-RNTI using the time index value corresponding to a single predetermined subframe. The method may include: transmitting a random access response message in response to receiving a random access preamble, wherein the random access response message includes a physical downlink control channel (PDCCH), wherein a cyclic redundancy checksum (CRC) of the PDCCH is scrambled with the RA-RNTI. The method may also include the above in combination with Figures 1 to 13 Any subset of the features, elements and operations described.

[0199] The embodiments of the present disclosure may be implemented in any of a variety of forms. For example, some embodiments may be implemented as computer-implemented methods, computer-readable storage media, or computer systems. Other embodiments may be implemented using one or more custom-designed hardware devices such as ASICs. Other embodiments may be implemented using one or more programmable hardware elements such as FPGAs.

[0200] In some embodiments, a non-transitory computer-readable storage medium may be configured such that it stores program instructions and / or data, wherein if the program instructions are executed by a computer system, the computer system is caused to perform a method, such as any one of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any method embodiments described herein, or any combination of such subsets.

[0201] In some embodiments, a user equipment device may be configured to communicate with and perform random access to: (a) a base station of an LPD network as variously described herein, and (b) a traditional base station in which the round-trip time between the base station and the user equipment device is significantly less than the time slot duration.

[0202] In some embodiments, the computer system may be configured to include a processor (or a group of processors) and a memory medium, wherein the memory medium stores program instructions, wherein the processor is configured to read and execute program instructions from the memory medium, wherein the executable program instructions are to implement any of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any method embodiments described herein, or any combination of such subsets). The computer system may be implemented in any of various forms. For example, the computer system may be a personal computer (in any of its various implementations), a workstation, a computer on a card, a dedicated computer in a box, a server computer, a client computer, a handheld device, a user equipment (UE) device, a tablet computer, a wearable computer, etc.

[0203] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0204] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to encompass all such variations and modifications.

Claims

1. A method for operating a base station, comprising: broadcasting an indication of a common delay value to user equipment (UE) devices in a cell coverage area of ​​the base station; receiving a random access preamble from a UE device after broadcasting an indication of the common delay value; determining a time slot in which the random access preamble is transmitted based on a configured correspondence between allowable time slots and a subset of an available set of random access preambles; determining a random access radio network temporary identifier, RA-RNTI, based on a parameter value including an index of the determined time slot; as well as A differential delay value is transmitted to the UE device, wherein the sum of the common delay value and the differential delay value indicates a propagation delay between the base station and the UE device, wherein an uncompensated round-trip propagation time between the base station and the UE device is greater than a radio frame duration, and wherein the common delay value is configured such that the differential delay is less than the radio frame duration.

2. The method according to claim 1, further comprising: Generating a random access response for the UE device; generating a physical downlink control channel (PDCCH), wherein the generating the PDCCH comprises scrambling a CRC of downlink control information using the RA-RNTI, wherein the downlink control information corresponds to the random access response; and The PDCCH and the random access response are transmitted.

3. The method according to claim 1, further comprising: A differential round trip time (RTT) is determined based on information including (a) a time slot in which the random access preamble is received at the base station and (b) a determined time slot in which the random access preamble is transmitted.

4. The method according to claim 1, further comprising: System information including random access configuration information is broadcasted, wherein the random access configuration information includes the common delay value.

5. The method according to claim 1, further comprising: An indication of a preamble configuration is transmitted, wherein the preamble configuration indicates the allowable time slots and the correspondence.

6. The method of claim 1, wherein the random access preambles in the available set are evenly divided among the subsets.

7. The method according to claim 1, wherein the base station is a gNB of the 3GPP 5G new air interface standard.

8. A base station, comprising: An antenna for performing wireless communication; a radio component coupled to the antenna; as well as a processing circuit coupled to the radio component and configured to: causing the radio component to broadcast an indication of a common delay value to user equipment (UE) devices within a cell coverage area of ​​the base station; receiving a random access preamble from a UE device after broadcasting an indication of the common delay value; determining a time slot in which the random access preamble is transmitted based on a configured correspondence between allowable time slots and a subset of an available set of random access preambles; determining a random access radio network temporary identifier, RA-RNTI, based on a parameter value including an index of the determined time slot; as well as The radio component is caused to transmit a differential delay value to the UE device, wherein a sum of the common delay value and the differential delay value indicates a propagation delay between the base station and the UE device, wherein an uncompensated round-trip propagation time between the base station and the UE device is greater than a radio frame duration, and wherein the common delay value is configured such that the differential delay is less than the radio frame duration.

9. The base station according to claim 8, wherein the processing circuit is further configured to: Generating a random access response for the UE device; generating a physical downlink control channel (PDCCH), wherein the generating the PDCCH comprises scrambling a CRC of downlink control information using the RA-RNTI, wherein the downlink control information corresponds to the random access response; and The PDCCH and the random access response are transmitted.

10. The base station of claim 8, wherein the processing circuit is further configured to: A differential round trip time (RTT) is determined based on information including (a) a time slot in which the random access preamble is received at the base station and (b) a determined time slot in which the random access preamble is transmitted.

11. The base station of claim 8, wherein the processing circuit is further configured to: System information including random access configuration information is broadcasted, wherein the random access configuration information includes the common delay value.

12. The base station of claim 8, wherein the processing circuit is further configured to: An indication of a preamble configuration is transmitted, wherein the preamble configuration indicates the allowable time slots and the correspondence.

13. The base station of claim 8, wherein the random access preambles in the available set are evenly divided among the subsets.

14. A non-transitory memory medium storing program instructions, wherein the program instructions, when executed by a processing circuit, cause a base station to perform the method according to any one of claims 1 to 7.

Images