Adaptively starting monitoring window and timer
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-02-06
- Publication Date
- 2026-08-13
Smart Images
Figure CN2025076060_13082026_PF_FP_ABST
Abstract
Description
ADAPTIVELY STARTING MONITORING WINDOW AND TIMERFIELD
[0001] Example embodiments of the present disclosure generally relate to the field of communication, and in particular, to a terminal device, a network device, methods, apparatuses, and a computer readable medium for adaptively starting a monitoring window and / or a timer.BACKGROUND
[0002] A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network.
[0003] Such communication networks operate in accordance with standards, such as those promulgated by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute) . Examples of such standards include the so-called 5G (5th Generation) standard or other standards promulgated by 3GPP.SUMMARY
[0004] In general, example embodiments of the present disclosure provide solutions for adaptively starting a monitoring window and / or a timer.
[0005] In a first aspect, there is provided a terminal device. The terminal device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: transmit, to a network device, a message in one or more uplink (UL) subframes; and determine a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.
[0006] In a second aspect, there is provided a network device. The network device comprises: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: transmit, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.
[0007] In a third aspect, there is provided a method. The method comprises: transmitting, to a network device, a message in one or more uplink (UL) subframes; and determining a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.
[0008] In a fourth aspect, there is provided a method. The method comprises: transmitting, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.
[0009] In a fifth aspect, there is provided an apparatus. The apparatus comprises: means for transmitting, to a network device, a message in one or more uplink (UL) subframes; and means for determining a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.
[0010] In a sixth aspect, there is provided an apparatus. The apparatus comprises: means for transmitting, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.
[0011] In a seventh aspect, there is provided a computer-readable storage medium comprising program instructions. The program instructions, when executed by an apparatus, cause the apparatus to perform at least the following: transmitting, to a network device, a message in one or more uplink (UL) subframes; and determining a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.
[0012] In an eighth aspect, there is provided a computer-readable storage medium comprising program instructions. The program instructions, when executed by an apparatus, cause the apparatus to perform at least the following: transmitting, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.
[0013] In a ninth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: transmit, to a network device, a message in one or more uplink (UL) subframes; and determine a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.
[0014] In a tenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: transmit, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.
[0015] In an eleventh aspect, there is provided a terminal device. The terminal device comprises: a transmitting circuitry configured to transmit, to a network device, a message in one or more uplink (UL) subframes; and a determining circuitry configured to determine a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.
[0016] In a twelfth aspect, there is provided a network device. The network device comprises: a transmitting circuitry configured to transmit, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.
[0017] It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Some example embodiments will now be described with reference to the accompanying drawings, in which:
[0019] FIG. 1 illustrates an example communication network in which embodiments of the present disclosure may be implemented;
[0020] FIG. 2 illustrates a schematic diagram of a Narrowband Internet of Things (NB-IoT) Non-Terrestrial Network (NTN) Time Division Duplex (TDD) frame structure;
[0021] FIG. 3 illustrates an example of a process flow for adaptively starting a monitoring window and / or a timer in accordance with some example embodiments of the present disclosure;
[0022] FIG. 4 illustrates a flowchart of an example user equipment (UE) method for adaptively starting a random access response (RAR) window and / or contention resolution (CR) timer in accordance with some example embodiments of the present disclosure;
[0023] FIG. 5 illustrates an example of a process flow for determining the start of the RAR window based on preamble grouping in accordance with some example embodiments of the present disclosure;
[0024] FIG. 6 illustrates a flowchart of an example method implemented at a terminal device in accordance with some embodiments of the present disclosure;
[0025] FIG. 7 illustrates a flowchart of an example method implemented at a network device in accordance with some embodiments of the present disclosure;
[0026] FIG. 8 illustrates a simplified block diagram of a device that is suitable for implementing some example embodiments of the present disclosure; and
[0027] FIG. 9 illustrates a block diagram of an example of a computer-readable medium in accordance with some example embodiments of the present disclosure.
[0028] Throughout the drawings, the same or similar reference numerals represent the same or similar elements.DETAILED DESCRIPTION
[0029] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.
[0030] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.
[0031] References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
[0032] It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.
[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and / or “including” , when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or” , mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.
[0034] As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable) : (i) a combination of analog and / or digital hardware circuit (s) with software / firmware and (ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (for example, firmware) for operation, but the software may not be present when it is not needed for operation.
[0035] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.
[0036] As used herein, the term “network” , “communication network” or “data network” refers to a network following any suitable communication standards, such as long term evolution (LTE) , LTE-advanced (LTE-A) , wideband code division multiple access (WCDMA) , high-speed packet access (HSPA) , narrow band Internet of things (NB-IoT) , wireless fidelity (Wi-Fi) and so on. Furthermore, the communications between a terminal device and a network device / element in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the fourth generation (4G) , 4.5G, the fifth generation (5G) , 5.5G (also known as 5G-Advanced) , IEEE 802.11 communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.
[0037] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) or a transmission and reception point (TRP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a remote radio unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a WiFi device, a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. In the following description, the terms “network device” , “AP device” , “AP” and “access point” may be used interchangeably.
[0038] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , a station (STA) or station device, or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (for example, remote surgery) , an industrial device and applications (for example, a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. In the following description, the terms “station” , “station device” , “STA” , “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.
[0039] The term “transceiver” may refer to any device that may be coupled to one or more antennas or antenna ports to wirelessly transmit and / or receive communication signals. The antennas or antenna ports may be the same or different types. The antennas or antenna ports may be located in different positions of an apparatus. One or more transceivers allow the apparatus to communicate with other devices that may be wired and / or wireless. The one or more transceivers may include processors, controllers, radios, sockets, plugs, buffers, or the like circuits to form one or more communication channels to one or more radio frequency units. The one or more transceivers may be integrated in an apparatus or a system, for example a cellular communication apparatus or system, a satellite communication apparatus or system, a WLAN system, or a short ranging system for example Bluetooth system.
[0040] For illustrative purposes, principle and example embodiments of the present disclosure will be described below with reference to FIG. 1 to FIG. 9. However, it is to be noted that these embodiments are given to enable the skilled in the art to understand inventive concepts of the present disclosure and implement the solution as proposed herein, and not intended to limit scope of the present application in any way.
[0041] FIG. 1 illustrates an example of an application scenario 100 in which some example embodiments of the present disclosure may be implemented. The application scenario 100, which is a part of a communication network, includes terminal devices and network devices.
[0042] In the descriptions of the example embodiments of the present disclosure, the network environment 100 may also be referred to as a communication system 100 (for example, a portion of a communication network) . The communication system 100 may be a non-terrestrial or terrestrial system.
[0043] For illustrative purposes only, various aspects of example embodiments will be described in the context of one or more terminal devices and network devices that communicate with one another. It should be appreciated, however, that the description herein may be applicable to other types of apparatus or other similar apparatuses that are referenced using other terminology.
[0044] As illustrated in FIG. 1, the communication network 100 may include a network device 110 (which may also be referred to as an eNB or gNB or a BS) . The communication network 100 may further include a terminal device 120 (which may also be referred to as user equipment 120 or UE 120. Although only one network device 110 and one terminal devices 120 are shown in FIG. 1, the numbers of the network device and the terminal device are not limited. In other words, there may be one or more network devices 110 and one or more terminal devices 120 in the network.
[0045] The network device 110 can provide services to the terminal device 120, and the network device 110 and the terminal device 120 may communicate data and control information with each other. In some embodiments, the network device 110 and the terminal device 120 may communicate with direct links / channels.
[0046] In the communication system 100, a link from the network device 110 to the terminal device 120 is referred to as a downlink (DL) , while a link from the terminal device 120 to the network device 110 is referred to as an uplink (UL) . In downlink, the network device 110 is a transmitting (TX) device (or a transmitter) and the terminal device 120 is a receiving (RX) device (or a receiver) . In uplink, the terminal device 120 is a transmitting (TX) device (or a transmitter) and the network device 110 is a RX device (or a receiver) . It is to be understood that the network device 110 may provide one or more serving cells. As illustrated in FIG. 1, the network device 110 provides one serving cell 102, and the terminal device 120 camps on the serving cell 102. In some embodiments, the network device 110 can provide multiple serving cells and the terminal device 120 may switch from a source cell to a target cell between the serving cells during its mobility. It is to be understood that the number of serving cell (s) shown in FIG. 1 is for illustrative purposes without suggesting any limitation. The serving cell (s) may include a primary cell (PCell) , a primary secondary cell (PSCell) or a SCell.
[0047] Communications in the network environment 100 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the fourth generation (4G) , the fifth generation (5G) and the sixth generation (6G) and on the like, wireless local network communication protocols such as institute for electrical and electronics engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future, such as universal mobile telecommunications system (UMTS) , long term evolution (LTE) , LTE-Advanced (LTE-A) , the fifth generation (5G) , new radio (NR) , the sixth generation (6G) , wireless fidelity (Wi-Fi) and worldwide interoperability for microwave access (WiMAX) standards, and employs any suitable communication technologies, including, for example, multiple-input multiple-output (MIMO) , orthogonal frequency division multiplexing (OFDM) , time division multiplexing (TDM) , frequency division multiplexing (FDM) , code division multiplexing (CDM) , Bluetooth, ZigBee, narrowband-Internet of things (NB-IoT) , enhanced machine type communication (eMTC) , enhanced mobile broadband (eMBB) , massive machine type communication (mMTC) , ultra-reliable low latency communication (URLLC) , carrier aggregation (CA) , dual connectivity (DC) , and new radio unlicensed (NR-U) technologies. The network environment 100 may be a Non-Terrestrial Network (NTN) network or a Terrestrial Network (TN) .
[0048] It is to be understood that the number of devices and their connection relationships and types shown in FIG. 1 are for illustrative purposes without suggesting any limitation. The communication system 100 may comprise any suitable number of devices adapted for implementing embodiments of the present disclosure.
[0049] It was agreed in the 3GPP release 19 NB-IoT NTN work item to support Time Division Duplex (TDD) mode. The work item includes the following objective:
[0050] The work item assumptions target low earth orbit (LEO) at 600 km and 1200 km altitude with earth-fixed or earth-moving cells in the 1616-1626.5 MHz MSS band.
[0051] FIG. 2 illustrates a schematic diagram of an agreed NB-IoT NTN TDD frame structure. As illustrated, the TDD frame structure include four UL occasions (UL1 to UL 4) and four DL occasions (DL1 to DL4) . In this disclosure, the term “UL occasion” means a number of contiguous UL subframes, and the term “DL occasion” means a number of contiguous DL subframes. In the example of FIG. 2 the number of contiguous UL subframes is 8 and the number of contiguous DL subframes is 8.
[0052] Regarding this TDD frame structure in FIG. 2, it was also agreed to consider to following design constraints: 1. At the satellite, all downlink NB-IoT channels / signals in a cell can only use one of the downlink slots in the TDD frame structure (DL1, DL2, DL3 or DL4) across 90ms periods. ο The same downlink slot is used in all the 90ms periods. 2. At the satellite, all uplink NB-IoT channels in a cell can only use one of the uplink slots in the TDD frame structure (UL1, UL2, UL3 or UL4) across 90ms periods. ο The same uplink slot is used in all the 90ms periods. 3. The one uplink slot and one downlink slot in the TDD frame structure have the same index (DL1 &UL1, DL2 &UL2, DL3 &UL3, or DL4 &UL4) . 4. NOTE: this does not imply that the only configuration (s) to be specified are according to these constraints.
[0053] Herein, the third design constraint means the UE when transmitting in occasion UL1 will have to monitor for a response in occasion DL1. As illustrated in FIG. 2, the separation or gap between an UL occasion and the paired DL occasion is 3*8.28 ms + 3 guard periods and thus at least 24.84 ms. This is significantly longer than the round-trip time (RTT) of the LEO 600 km deployment, which would be 4 ms for the regenerative architecture (eNB on board the satellite) and at least 8 ms for the transparent architecture (eNB on Earth) when the UE is in the nadir of the satellite. Furthermore, for the worst case, if the UE is located in the minimum elevation angle of the satellite, the RTT could be 12.88ms and 25.76ms, as described in 3GPP technical reports (TR) 38.821 section 4.2.
[0054] 3GPP technical specifications (TS) 36.321 defines the NB-IoT UE after transmitting the msg1 / PRACH preamble shall monitor for the msg2 / RAR as follows.
[0055] When the UE has received the RAR it will transmit the msg3, based on the UL grant in the RAR, and then it monitors for the Contention Resolution (msg4) as follows (according to TS 36.321) :
[0056] According to TS 36.331, the PDDCH period T can be in the range of 1*1.5 subframes to 2048*64 subframes. Since the RAR window is 2-10 PDCCH periods, a very wide range of window lengths can be configured. The CR timer is even longer given the 1-64 PDCCH period range.
[0057] Embodiments of the disclosure target addressing the problem of the RAR window and CR timer start happening too soon according to legacy specifications if applied to the NB-IoT NTN TDD. Specifically, the RAR window is defined to start at the end of the preamble repetition + 4 subframes (when #repetitions < 64 or for TDD mode) + UE-eNB RTT. Likewise, the CR timer is defined to start at the end of the PUSCH transmission repetition + UE-eNB RTT.
[0058] Thus, in both cases the start of the window / timer is offset according to the UE-eNB RTT. However, as noted previously, the UE-eNB RTT can be in the range [4 ms : 25.76 ms] depending on the architecture, NTN gateway location and the elevation angle (to the satellite) observed from UE. If the UE-eNB RTT is a low value (e.g., ～4ms) , it is significantly shorter than the ～25 ms offset between an UL and DL occasion in the NB-IoT TDD frame structure and therefore there is a risk that the UE starts the window / timer too early, which will result in the unnecessary power consumption in the UE to start PDCCH monitoring and also reduce the efficiency of the RAR window / CR timer with restriction of the PDCCH location. If the UE-eNB RTT is a high value (e.g., ～26ms) , the UE may start the window / timer a late in the DL occasion (as the UL and DL is ～25ms in the TDD frame structure) .
[0059] Furthermore, depending on the configured RAR window / CR timer length, since the UE can only monitor one downlink slot (i.e., 8ms) in the 90ms of the TDD frame structure, the UE may also monitor in vain or experience the window / timer ends before the UE has detected the PDCCH.
[0060] Furthermore, a related issue of the UL-DL pairs of the NB-IoT TDD NTN frame structure is that many UEs may expect to be scheduled in the first DL occasion that follows the UL occasion. This is particularly challenging for RAR / Msg2, because the preambles are transmitted in single subcarriers &multiplexed via preambles, which means the UL preamble capacity is very large compared to the DL capacity required for responding to the preambles.
[0061] Based on these problems the present disclosure proposes a solution to adjust the start of RAR window and CR timer. It should be understood that the embodiments of the present disclosure can also be applied to different scenarios other than the NB-IoT TDD NTN network and can adjust the start of monitoring windows and timers other than the RAR window and CR timer.
[0062] FIG. 3 illustrates an example of a process flow 300 for adaptively starting a monitoring window and / or a timer in accordance with some example embodiments of the present disclosure. For ease of understanding, the process flow 300 will be described with reference to FIG. 1. It would be appreciated that although the process flow 300 has been described referring to the communication network 100 of FIG. 1, this process flow 300 may be likewise applied to other similar communication scenarios.
[0063] At 302, the terminal device 120 transmits a message in one or more uplink (UL) subframes to the network device 310. The message may be Msg1 or Msg3 in a random access channel (RACH) procedure. The terminal device 120 may perform multiple UL transmission repetitions of the message and expects to receive a response in downlink (DL) subframes. The terminal device 120 may start a monitoring window or a timer for the response. If no response is received in the monitoring window or before expiry of the timer, the terminal device may perform a further UL transmission .
[0064] The terminal device 120 may be a NB-IoT UE, and the message transmitted at 302 may be a Narrowband Physical Random Access Channel (NPRACH) Msg1 preamble or Narrowband Physical Uplink Shared Channel (NPUSCH) Msg3. For Msg1 case, the monitoring window is a RAR window. For Msg3 case, the timer is a Contention Resolution (CR) timer.
[0065] In some implementations (aNTN TDD mode) , the network device 120 only transmits the response in the DL occasions configured to the terminal device 120. The DL occasions configured to the terminal device 120 may be gapped (separated in time i.e. UL and DL subframes are not contiguous) from the UL subframes of UL occasions. With reference to FIG. 2, if the terminal device 120 performs an UL transmission repetition in a UL occasion (e.g., UL1) , it can only receive the response in subframes of the paired DL occasion (DL1) .
[0066] Adjusting the start of the monitoring window or timer would be beneficial to avoid unnecessary power consumption in the UE if they start too early. In some embodiments, the terminal device 120 may determine whether its serving cell operates in NTN TDD mode, if so, it may adjust the start of the monitoring window or the timer.
[0067] At 304, the terminal device 120 determines the start of the monitoring window or the timer for receiving a response to the message in DL subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message 302, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.
[0068] In some embodiments, the monitoring window or the timer may start at the subframe containing the last UL transmission repetition plus an offset equal to max (X + RTT, a time from last UL transmission repetition to next DL subframe) , where X denotes a number of subframes. In some embodiments, X may be 0, 4, or 41 subframes. Other numbers are also possible. For NTN, the RTT can be determined based on NW architecture (regenerative or transparent) , the elevation angle and the altitude of the satellite. For the transparent NW architecture the UE will account for the feeder link delay between the eNB on Earth and the satellite, while for both regenerative and transparent architectures the UE accounts for the service link propagation delay between the satellite and the UE. The satellite position and possibly feeder link delay information is available in satellite assistance information, which is broadcast in NTN.
[0069] If the starting subframe is an available DL subframe of this cell (i.e., a subframe of the DL occasion in which the network device may transmit a DL response to the terminal device) , the terminal device 120 may follow the rule. If the starting subframe is not an available DL subframe for this cell (in case X+RTT was the larger value) , which means the network device 120 does not transmit the DL response in that subframe, the terminal device 120 may start the monitoring window or the timer at a next available DL subframe.
[0070] In some embodiments, the monitoring window or the timer may be defined to always start at the start of the next DL occasion. Based on NW implementation, the terminal device 120 may determine to start the monitoring window or the timer at the start of the next DL occasion. For example, this embodiment may be applied when the UE-eNB RTT is always shorter (due to the type of deployment including satellite altitude, satellite coverage, gateway location) than the gap between UL and DL.
[0071] Then, the terminal device 120 may start the monitoring window or the timer 305 for receiving the possible response 306 from the network device 110. For the RAR case, the terminal device 120 monitors for PDCCH scheduling the RAR within the RAR window; if no response is received in the RAR window, it may perform a further transmission of Msg1. For the CR case, the terminal device 120 monitors for Msg4 when the CR timer is running; if no response is received, it may perform a further transmission of Msg3.
[0072] FIG. 4 illustrates a flowchart of an example UE method 400 for adaptively starting a RAR window and / or CR timer in accordance with some example embodiments of the present disclosure. The method 400 can be implemented by the terminal device 120 in FIG. 1.
[0073] At 401, the terminal device 120 determines that the cell operates in NTN TDD mode. In the NTN TDD mode, the NW only transmits DL signaling to the terminal device 120 in the configured DL occasions. Thus, the terminal device 120 may adjust the start of the monitoring window or the timer based on the starting subframes of the DL occasions.
[0074] At 402, the terminal device 120 transmits Msg 1 or Msg 3 to eNB during a PRACH procedure. For Msg1 case, the terminal device 120 may adjust the start of the RAR window. For Msg3 case, the terminal device 120 may adjust the start of the CR timer.
[0075] At 403, the terminal device 120 estimates the UE-eNB round-trip time (RTT) . The RTT can be determined based on NW architecture (regenerative or transparent) , the elevation angle and the altitude of the satellite.
[0076] At 404, the terminal device 120 determines t = max (X subframes + RTT, time from last UL transmission repetition to next DL subframe) , where X may be 0, 4, or 41.
[0077] At 405, the terminal device 120 determines if an offset t is an available DL subframe in the DL occasion. If so, the method 400 proceeds to 406, the terminal device 120 starts the RAR window / CR timer at the offset t. If the offset t is not available DL subframe, the method 400 proceeds to 407, the terminal device 120 delay the start of the RAR window / CR timer until the next available DL subframe.
[0078] In some embodiments, the terminal device 120 may configured to only count the DL subframes, which are within the DL occasions, when determining the remaining value of the RAR window and CR timer. This enables the network and UE to handle a short RAR window / CR timer.
[0079] To handle the DL resource congestion (in particular in response to the preamble / Msg1 transmission) , the following embodiments provide a further enhancement to the start offset calculation (in addition to the offset as discussed) .
[0080] The offset for the RAR window start (and possibly also CR timer start) can be further offset based on UE grouping information. In some embodiments, the UE may determine a group to which it belongs; and add an additional offset to the start of a monitoring window or the timer based on the group that it belongs to.
[0081] The additional offset for the RAR window start (and possibly also CR timer start) can be based on a split of the Msg1 transmissions into N groups. In some embodiments, the split can be based on at least one of: a configured group identity (ID) , a preamble used for transmitting Msg1, an NPRACH occasion in time domain used for transmitting the Msg1, an NPRACH occasion in frequency domain used for transmitting the Msg1 (e.g., number of subcarriers, starting subcarrier) , or a preamble format used for transmitting the Msg1.
[0082] Depending on which group n the UE belongs to (based on the Msg1 transmission) , the additional offset_n may be added to the PDCCH monitoring start: last preamble repetition + max (X+RTT, time from last preamble to next DL subframe) + offset_n. In some embodiments, the network may configure the mapping from Msg1 transmission to the N groups and the offset_n. The offset_n may be offsetting the window by one or more subframes within the DL occasion or offset to the next possible DL occasions (i.e. using a multiple of 90ms in FIG. 2) .
[0083] In one embodiment, a reference offset (offset_ref) can be configured by the network after which the UE scales the offset with the group ID_number (e.g., offset_n = offset_ref *group_ID_n) .
[0084] In one embodiment, all the UEs may start the RAR window or the CR timer according to offset as discussed with reference to FIG. 3 and FIG. 4. Then, a group ID can be indicated via DCI of PDCCH (either in the DCI scheduling the RAR, a different DCI or using a different RNTI) . The UEs in the group that are not indicated in PDCCH are configured to stop RAR window or CR timer and restart in the next configured DL occasion.
[0085] FIG. 5 illustrates an example of a process flow 500 for determining the start of the RAR window based on preamble grouping in accordance with some example embodiments of the present disclosure. For ease of understanding, the process flow 500 will be described with reference to FIG. 1. It would be appreciated that although the process flow 500 has been described referring to the communication network 100 of FIG. 1, this process flow 500 may be likewise applied to other similar communication scenarios.
[0086] At 502, the terminal device 120 determines that the cell operates in NTN TDD mode.
[0087] At 504, the terminal device 120 receives from the network device 110 a PRACH and RAR configuration including preamble group information. The preamble group information may indicate one or more of: a group ID, a preamble used for transmitting Msg1, an NPRACH occasion in time domain used for transmitting the Msg1, an NPRACH occasion in frequency domain used for transmitting the Msg1, or a preamble format used for transmitting the Msg1.
[0088] At 506, the terminal device 120 transmits Msg1 preamble to the network device 110.
[0089] At 507, the terminal device 120 determines which group it belongs to based on the preamble group information.
[0090] At 508, the terminal device 120 determines the additional offset for the RAR window based on the preamble group.
[0091] At 510, the terminal device 120 determines when to start the RAR window based on max (X subframes + RTT, time from last UL repetition to the next DL subframe) plus the additional offset.
[0092] Then, the terminal device 120 may start the RAR window 511 for receiving the possible RAR 512 from the network device 110. If no RAR is received in the RAR window 511, the terminal device 120 may perform a further repetition of Msg1.
[0093] In some embodiments, if the next DL occasion of contiguous DL subframes is occupied more than a threshold, for example, by control information (e.g., master information block (MIB) , system information block (SIB) , primary synchronization signal (PSS) , and / or second synchronization signal (SSS) , the terminal device 120 may skip the monitoring until the subsequent DL subframe (i.e. to consider the earlier DL subframe unavailable) . That is, the start of the RAR window can be delayed until the starting subframe of the next DL occasion.
[0094] The threshold might be configured by NW or predefined in number of subframes (or slots / symbols) or a relatively value (e.g., 50%) , as a function of the random access response window / CR timer length, or as a function of the coverage enhancement level (i.e., depending on number of repetitions to be used for the NPDCCH scheduling msg2 / 4) .
[0095] FIG. 6 illustrates a flowchart of an example method 600 implemented at a terminal device in accordance with some embodiments of the present disclosure. For ease of understanding, the method 600 will be described from the perspective of the terminal device 120 with reference to FIG. 1.
[0096] At block 610, the terminal device 120 transmits, to a network device 110, a message in one or more uplink (UL) subframes. At block 620, the terminal device determines a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.
[0097] In some embodiments, to determine the start of the monitoring window or the timer for receiving the response to the message in the DL subframes that are gapped from the one or more UL subframes, the terminal device 120 may determine the RTT between the terminal device and the network device; and determine a starting subframe of the monitoring window or the timer at a subframe containing the end of the last UL transmission repetition plus a maximum between: a number of subframes plus the RTT, and the time from the last UL transmission repetition to the next DL subframe.
[0098] In some embodiments, the number of subframes may comprise 0, 4 or 41 subframes.
[0099] In some embodiments, the terminal device may further determine whether the starting subframe is an available DL subframe; and based on determining that the starting subframe is not an available DL subframe, start the monitoring window or the timer at a next available DL subframe.
[0100] In some embodiments, to determine the start of the monitoring window or the timer for receiving the response to the message, the terminal device may determine to start the monitoring window or the timer at the start of the next DL occasion.
[0101] In some embodiments, the message may comprise a Narrowband Physical Random Access Channel (NPRACH) Msg1 preamble, and the monitoring window is a Random Access Response (RAR) window.
[0102] In some embodiments, the message may comprise a Narrowband Physical Uplink Shared Channel (NPUSCH) Msg3, and the timer is a Contention Resolution (CR) timer.
[0103] In some embodiments, the terminal device may further determine that a serving cell operates in a Non-Terrestrial Network (NTN) Time Division Duplex (TDD) mode.
[0104] In some embodiments, the terminal device may further determine a group to which the terminal device belongs; and add an additional offset to the start of a monitoring window or the timer based on the group that the terminal device belongs to.
[0105] In some embodiments, to determine the group to which the terminal device belongs, the terminal device is caused to determine the group based on at least one of: a configured group identity (ID) , a preamble used for transmitting Msg1, an NPRACH occasion in time domain used for transmitting the Msg1, an NPRACH occasion in frequency domain used for transmitting the Msg1, or a preamble format used for transmitting the Msg1.
[0106] In some embodiments, the additional offset offsets the start of the monitoring window or the timer by one or more subframes within a DL occasion or to a next possible DL occasion.
[0107] In some embodiments, the additional offset may be based on a reference offset and a group ID of the terminal device.
[0108] In some embodiments, the terminal device may further receive downlink control information (DCI) after starting the monitoring window or the timer; and in response to determining that the DCI does not indicate a group ID of the terminal device, stop the monitoring window or the timer, and restart the monitoring window or the timer in a next configured DL occasion.
[0109] In some embodiments, the terminal device may further determine whether a DL occasion of contiguous DL subframes is occupied more than a threshold; and based on determining that the DL occasion is occupied more than the threshold, delay the start of the monitoring window or the timer until a subsequent DL subframe in a next DL occasion.
[0110] In some embodiments, the threshold may be configured or predefined as a function of a length of the monitoring window or the timer, or as a function of a coverage enhancement level.
[0111] In some embodiments, the terminal device is further caused to determine a remaining value of the monitoring window and the timer by counting DL subframes within DL occasions.
[0112] In some embodiments, the terminal device comprises a Narrowband Internet of Things (NB-IoT) user equipment (UE) .
[0113] FIG. 7 illustrates another flowchart of an example method 700 implemented at a network device in accordance with some embodiments of the present disclosure. For ease of understanding, the method 700 will be described from the perspective of the network device 110 with reference to FIG. 1.
[0114] At block 710, the network device 110 transmits, to a terminal device 120, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.
[0115] In some embodiments, the preamble transmission grouping information may indicate at least one of: a group identity (ID) , a preamble used for transmitting Msg1, an NPRACH occasion in time domain used for transmitting the Msg1, an NPRACH occasion in frequency domain used for transmitting the Msg1, or a preamble format used for transmitting the Msg1.
[0116] In some embodiments, the network device may further configure the terminal device with a reference offset, wherein the reference offset is used to determine a start of a monitoring window or a timer of the terminal device during a Narrowband Physical Random Access Channel (NPRACH) procedure.
[0117] In some embodiments, the network device may further transmit, in response to receiving a NPRACH Msg1 preamble or a Narrowband Physical Uplink Shared Channel (NPUSCH) Msg3, DCI indicating a group ID to the terminal device.
[0118] In some embodiments, the network device may further configure the terminal device with a threshold related to occupancy within a DL occasion.
[0119] In some embodiments, an apparatus capable of performing the method 600 (for example, the terminal device 120) may comprise means for performing the respective steps of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.
[0120] In some example embodiments, the apparatus comprises: means for transmitting, to a network device, a message in one or more uplink (UL) subframes; and means for determining a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.
[0121] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 600. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.
[0122] In some embodiments, an apparatus capable of performing the method 700 (for example, the network device 110) may comprise means for performing the respective steps of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.
[0123] In some embodiments, the apparatus may comprise: means for transmitting, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.
[0124] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 700. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.
[0125] FIG. 8 illustrates a simplified block diagram of a device 800 that is suitable for implementing some example embodiments of the present disclosure. The device 800 may be provided to implement a communication device, for example, the network device 110 or the terminal device 120 as shown in FIG. 1. As shown, the device 800 includes one or more processors 810, one or more memories 820 coupled to the processor 810, and one or more communication modules 840 coupled to the processor 810.
[0126] The communication module 840 is for bidirectional communications. The communication module 840 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.
[0127] The processor 810 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 800 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.
[0128] The memory 820 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 824, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 822 and other volatile memories that will not last in the power-down duration.
[0129] A computer program 830 includes computer executable instructions that are executed by the associated processor 810. The program 830 may be stored in the ROM 824. The processor 810 may perform any suitable actions and processing by loading the program 830 into the RAM 822.
[0130] The embodiments of the present disclosure may be implemented by means of the program 830 so that the device 800 may perform any process of the disclosure as discussed with reference to FIGS. 3 to 7. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.
[0131] In some example embodiments, the program 830 may be tangibly contained in a computer-readable medium which may be included in the device 800 (such as in the memory 820) or other storage devices that are accessible by the device 800. The device 800 may load the program 830 from the computer-readable medium to the RAM 822 for execution. The computer-readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like.
[0132] FIG. 9 illustrates a block diagram of an example of a computer-readable medium 900 in accordance with some example embodiments of the present disclosure. The computer-readable medium 900 has the program 830 stored thereon. It is noted that although the computer-readable medium 900 is depicted in form of CD or DVD in FIG. 9, the computer-readable medium 900 may be in any other form suitable for carry or hold the program 830.
[0133] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.
[0134] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the methods 600 to 700 as described above with reference to FIGS. 6 to 7. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.
[0135] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.
[0136] In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer-readable medium, and the like.
[0137] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium would include 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) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. The term “non-transitory, ” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM) .
[0138] Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.
[0139] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
Claims
1.A terminal device comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to:transmit, to a network device, a message in one or more uplink (UL) subframes; anddetermine a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.2.The terminal device of claim 1, wherein to determine the start of the monitoring window or the timer for receiving the response to the message in the DL subframes that are gapped from the one or more UL subframes, the terminal device is caused to:determine the RTT between the terminal device and the network device; anddetermine a starting subframe of the monitoring window or the timer at a subframe containing the end of the last UL transmission repetition plus a maximum between: a number of subframes plus the RTT, and the time from the last UL transmission repetition to the next DL subframe.3.The terminal device of claim 2, wherein the number of subframes comprise 0, 4 or 41 subframes.4.The terminal device of claim 2, wherein the terminal device is further caused to:determine whether the starting subframe is an available DL subframe; andbased on determining that the starting subframe is not an available DL subframe, start the monitoring window or the timer at a next available DL subframe.5.The terminal device of claim 1, wherein to determine the start of the monitoring window or the timer for receiving the response to the message, the terminal device is caused to:determine to start the monitoring window or the timer at the start of the next DL occasion.6.The terminal device of claim 1, wherein the message comprises a Narrowband Physical Random Access Channel (NPRACH) Msg1 preamble, and the monitoring window is a Random Access Response (RAR) window.7.The terminal device of claim 1, wherein the message comprises a Narrowband Physical Uplink Shared Channel (NPUSCH) Msg3, and the timer is a Contention Resolution (CR) timer.8.The terminal device of claim 1, wherein the terminal device is further caused to:determine that a serving cell operates in a Non-Terrestrial Network (NTN) Time Division Duplex (TDD) mode.9.The terminal device of claim 1, wherein the terminal device is further caused to:determine a group to which the terminal device belongs; andadd an additional offset to the start of a monitoring window or the timer based on the group that the terminal device belongs to.10.The terminal device of claim 9, wherein to determine the group to which the terminal device belongs, the terminal device is caused to determine the group based on at least one of:a configured group identity (ID) ,a preamble used for transmitting Msg1,an NPRACH occasion in time domain used for transmitting the Msg1,an NPRACH occasion in frequency domain used for transmitting the Msg1, ora preamble format used for transmitting the Msg1.11.The terminal device of claim 9 or 10, wherein the additional offset offsets the start of the monitoring window or the timer by one or more subframes within a DL occasion or to a next possible DL occasion.12.The terminal device of any of claims 9 to 11, wherein the additional offset is based on a reference offset and a group ID of the terminal device.13.The terminal device of any of claims 1 to 12, wherein the terminal device is further caused to:receive downlink control information (DCI) after starting the monitoring window or the timer; andin response to determining that the DCI does not indicate a group ID of the terminal device, stop the monitoring window or the timer, and restart the monitoring window or the timer in a next configured DL occasion.14.The terminal device of any of claims 1 to 13, wherein the terminal device is further caused to:determine whether a DL occasion of contiguous DL subframes is occupied more than a threshold; andbased on determining that the DL occasion is occupied more than the threshold, delay the start of the monitoring window or the timer until a subsequent DL subframe in a next DL occasion.15.The terminal device of claim 14, wherein the threshold is configured or predefined as a function of a length of the monitoring window or the timer, or as a function of a coverage enhancement level.16.The terminal device of any of claims 1 to 15, wherein the terminal device is further caused to determine a remaining value of the monitoring window and the timer by counting DL subframes within DL occasions.17.The terminal device of any of claims 1 to 16, wherein the terminal device comprises a Narrowband Internet of Things (NB-IoT) user equipment (UE) .18.A network device comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to:transmit, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.19.The network device of claim 18, wherein the preamble transmission grouping information indicates at least one of:a group identity (ID) ,a preamble used for transmitting Msg1,an NPRACH occasion in time domain used for transmitting the Msg1,an NPRACH occasion in frequency domain used for transmitting the Msg1, ora preamble format used for transmitting the Msg1.20.The network device of claim 18 or 19, wherein the network device is further caused to:configure the terminal device with a reference offset,wherein the reference offset is used to determine a start of a monitoring window or a timer of the terminal device during a Narrowband Physical Random Access Channel (NPRACH) procedure.21.The network device of any of claims 18 to 20, wherein the network device is further caused to:in response to receiving a NPRACH Msg1 preamble or a Narrowband Physical Uplink Shared Channel (NPUSCH) Msg3, transmit DCI indicating a group ID to the terminal device.22.The network device of any of claims 18 to 21, wherein the network device is further caused to:configure the terminal device with a threshold related to occupancy within a DL occasion.23.A method comprising:transmitting, to a network device, a message in one or more uplink (UL) subframes; anddetermining a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.24.A method comprising:transmitting, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.25.An apparatus comprising:means for transmitting, to a network device, a message in one or more uplink (UL) subframes; andmeans for determining a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.26.An apparatus comprising:means for transmitting, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.27.A computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least:transmitting, to a network device, a message in one or more uplink (UL) subframes; anddetermining a start of a monitoring window or a timer for receiving a response to the message in downlink (DL) subframes that are gapped from the one or more UL subframes, based on the last UL transmission repetition of the message, a Round Trip Time (RTT) between the terminal device and the network device, and a time from the last UL transmission repetition to a next DL subframe.28.A computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least:transmitting, to a terminal device, a Narrowband Physical Random Access Channel (NPRACH) and Random Access Response (RAR) configuration including preamble transmission grouping information.