System and method for timing enhancement in storage and forwarding mode

Abstract

Systems and methods for timing enhancement in storage and forwarding modes are provided. The wireless communication node may configure a wait duration indicating a duration of a next service cycle to the satellite and a service duration indicating a duration of a service cycle of the satellite. The wireless communication node may send a wait duration and a service duration for use by the wireless communication device during the random access procedure.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communications, including but not limited to systems and methods for timing enhancement in a store and forward mode. Background Art

[0002] Coverage is a fundamental aspect of cellular network deployment. Mobile operators rely on different types of network nodes to provide blanket coverage in their deployments. Therefore, new types of network nodes are considered to increase the flexibility of mobile operators in network deployment. For example, some systems or architectures introduce integrated access and backhaul (IAB), which is a new type of network node that does not require a wired backhaul and can be enhanced in some other systems. Another type of network node is the RF repeater, which simply amplifies and retransmits any signal they receive. RF repeaters have been widely deployed in 2G, 3G, and 4G to supplement the coverage provided by conventional full-stack units. Summary of the invention

[0003] The exemplary embodiments disclosed herein are intended to solve problems related to one or more problems existing in the prior art, and provide additional features, which will become apparent when referring to the following detailed description in conjunction with the accompanying drawings. According to various embodiments, example systems, methods, devices, and computer program products are disclosed herein. However, it should be understood that these embodiments are presented in an exemplary manner, not restrictive, and it will be apparent to a person of ordinary skill in the art who has read this disclosure that various modifications can be made to the disclosed embodiments while remaining within the scope of this disclosure.

[0004] At least one aspect is directed to a system, method, apparatus, or computer-readable medium. A wireless communication node (e.g., a base station (BS), which may be part of a regenerated satellite or, for example, separate from a satellite) may configure a time duration (e.g., T) indicating a next service period to a satellite. wait ) and the duration of the service period of the satellite (e.g., T serve ). The wireless communication node may send the waiting duration and the service duration (an indication thereof) for use by a wireless communication device (e.g., a user equipment (UE)) during a random access procedure. In some embodiments, the wireless communication node (e.g., a regenerative satellite) may send the waiting duration and the service duration directly to the UE. In some embodiments, the wireless communication node (e.g., a BS) may send the waiting duration and the service duration to the UE via a satellite (e.g., a transparent satellite). The random access procedure may include a 4-step random access procedure, or a 2-step random access procedure or a non-contention random access procedure.

[0005] In some embodiments, the waiting duration may include at least one of the following: the duration of one orbital cycle of a satellite, the processing duration at the wireless communication node, the round-trip propagation time between a satellite and a wireless communication node, the round-trip propagation time between a satellite and a wireless communication device, a fixed value, or the sum of a fixed value and an offset value.

[0006] In some implementations, the wireless communication node may send the waiting duration and the service duration to the satellite via at least one of: master information block (MIB) signaling, system information block (SIB) signaling, or radio resource control (RRC) signaling. The satellite may store the waiting duration and the service duration. The satellite may send the waiting duration and the service duration to the wireless communication device.

[0007] In some implementations, during a first instance of the service duration, the wireless communication device may wait for a first instance of the period to start (eg, Fig. 9 The satellite may respond to the first instance of the waiting period expiring (e.g., Fig. 9 The wireless communication device may receive the Msg2 or MsgB from the satellite in a random access response (RAR) window having a delay including the sum of the first timing advance (TA1) and the second timing advance (TA2). During the second instance of the service duration, the wireless communication device may receive the Msg2 or MsgB at the start time of the second instance of the waiting period (e.g., Fig. 9 At t5 in the contention resolution window, the wireless communication device sends Msg3 having a timing advance including the sum of TA1 and TA2. After the second instance of the waiting period expires, the wireless communication device can monitor after a delay including the sum of the third timing advance (TA3) and the fourth timing advance (TA4) to receive Msg4 in the contention resolution window.

[0008] In some embodiments, the wireless communication device may determine to send Msg1, Msg3, or MsgA if (e.g., under the following conditions) at least one of the following occurs: the calculated elevation angle is greater than an elevation angle threshold, the measured reference signal received power (RSRP) is higher than an RSRP threshold, the calculated distance is less than a distance threshold between the wireless communication device and the satellite, or the remaining portion of the service duration calculated by the wireless communication device is greater than the sum of a predetermined duration (e.g., K, a predetermined duration of DCI predetermined Msg3) and a round-trip propagation time between the satellite and the wireless communication device.

[0009] In some embodiments, TA1 may be a start time of a first instance of a waiting period (eg, Fig. 9TA2 can be the propagation delay calculated when the satellite sends Msg2 or MsgB to the wireless communication device (for example, Fig. 9 TA3 may be the propagation delay between the wireless communication device and the satellite when the wireless communication device sends Msg3 (e.g., Fig. 9 TA4 may be the propagation delay between the wireless communication device and the satellite when the wireless communication device receives Msg4 (e.g., Fig. 9 The propagation delay between the wireless communication device and the satellite is calculated using t8).

[0010] In some implementations, when the waiting period expires, if the wireless communication device has not received (e.g., has not successfully received) Msg2, Msg4, or MsgB, then after a defined offset time (ΔT, e.g., mapped to a higher uplink (UL) coverage), the wireless communication device may resend Msg1, Msg3, or MsgA to the satellite at the start time of another instance of the waiting period.

[0011] In some embodiments, the wireless communication node on the satellite sends the wait duration and the service duration to the wireless communication device. During the first instance of the service duration, the wireless communication device can wait for the first instance of the service period at the start time (e.g., Fig.13 The satellite may send Msg2 or MsgB to the wireless communication device (e.g., Fig.13 In response to the expiration of the first instance of the waiting period, the wireless communication device may receive Msg2 from the satellite in a random access response (RAR) window having a delay including two times the timing advance (TA). During a second instance of the service duration, the wireless communication device may receive Msg2 at the start time of the second instance of the waiting period (e.g., Fig.13 After the second instance of the waiting period expires, the wireless communication device may monitor after a delay including twice TA to receive Msg4 in the contention resolution window. TA may be a propagation delay between the wireless communication device and the satellite. When the waiting period expires, if the wireless communication device does not receive Msg2, Msg4, or MsgB, then after a defined offset time (ΔT, e.g., mapped to a higher uplink (UL) coverage), the wireless communication device may resend Msg1, Msg3, or MsgA to the satellite at the start time of another instance of the waiting period.

[0012] In some embodiments, the wireless communication node (e.g., gNB-CU) may send the wait duration and the service duration (an indication thereof) to the satellite. The satellite may store the wait duration and the service duration. The satellite may send the wait duration and the service duration to the wireless communication device. During the first instance of the service duration, the wireless communication device may, at the start time of the first instance of the wait period (e.g., Fig.17 The satellite may respond to the first instance of the waiting period (e.g., Fig.17 The wireless communication device may receive the Msg2 or MsgB and the first radio resource control (RRC) information from the satellite during a random access response (RAR) window having a delay of the sum of the first timing advance (TA1) and the second timing advance (TA2) or after the delay. During the second instance of the service duration, the wireless communication device may wait for the second instance of the service duration at the start time of the second instance of the waiting period (e.g., Fig.17 At t4 in the contention resolution window, the wireless communication device may send Msg3 having a timing advance of / after the sum of TA1 and TA2. After the second instance of the waiting period expires, the wireless communication device may monitor after a delay of the sum of the third timing advance (TA3) and the fourth timing advance (TA4) to receive Msg4 and the second RRC information in / during the contention resolution window.

[0013] In some embodiments, TA1 may be a start time of a first instance of a waiting period (eg, Fig.17 TA2 can be the propagation delay calculated when the satellite sends Msg2 or MsgB to the wireless communication device (for example, Fig.17 TA3 may be the propagation delay between the wireless communication device and the satellite calculated / determined (e.g., using the GNSS module of the wireless communication device) when the wireless communication device sends Msg3 (e.g., Fig.17TA4 may be a propagation delay between the wireless communication device and the satellite calculated / determined (e.g., using a GNSS module of the wireless communication device) at t4 in the wireless communication device. TA4 may be a propagation delay between the wireless communication device and the satellite calculated when the wireless communication device receives Msg4. When the waiting period expires, if the wireless communication device does not receive Msg2, Msg4, or MsgB, then after a defined offset time (ΔT, e.g., mapped to a higher uplink (UL) coverage), the wireless communication device may resend Msg1, Msg3, or MsgA to the satellite at the start time of another instance of the waiting period (e.g., attempt to send another Msg1, Msg3, or MsgB). The wireless communication device may receive Msg2 or MsgB from the satellite in a RAR window that is extended to include a common timing advance of multiple wireless communication devices (e.g., configured / determined by the wireless communication node) or a maximum round-trip propagation delay between the wireless communication device and the satellite. The wireless communication device may monitor to receive Msg4 within a contention resolution window that is extended / modified to include a common timing advance or a maximum round-trip propagation delay between the wireless communication device and the satellite.

[0014] In some embodiments, a wireless communication device (e.g., a UE) may receive a configuration to be used during a random access procedure, the configuration including a wait duration (e.g., T ) indicating the duration of the next service period of the satellite. wait ) and a service duration indicating the duration of the satellite's service period (e.g., T serve ). The waiting duration and the service duration may be configured by a wireless communication node (eg, a BS, which may be part of a regenerative satellite, for example). BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Various exemplary embodiments of the present solution are described in detail below with reference to the following drawings. The drawings or diagrams are provided for illustrative purposes only and depict only exemplary embodiments of the present solution to facilitate the reader's understanding of the present solution. Therefore, the drawings should not be considered as limiting the breadth, scope or applicability of the present solution. It should be noted that for clarity and ease of illustration, these drawings are not necessarily drawn to scale.

[0016] Figure 1 An example cellular communication network is shown according to some embodiments of the present disclosure, in which the techniques disclosed herein may be implemented;

[0017] Figure 2 A block diagram showing an example base station and user equipment device according to some embodiments of the present disclosure;

[0018] Figure 3A schematic diagram showing operation in a store and forward mode in a non-terrestrial network (NTN) according to some embodiments of the present disclosure;

[0019] Figure 4 A schematic diagram showing modification operations in a store and forward mode between satellites according to some embodiments of the present disclosure;

[0020] Figure 5 A schematic diagram showing a transparent satellite in a non-terrestrial network (NTN) according to some embodiments of the present disclosure;

[0021] Figure 6 A schematic diagram showing a regenerative satellite in a non-terrestrial network (NTN) according to some embodiments of the present disclosure;

[0022] Figure 7 A schematic diagram showing a regenerative satellite with separated gNB-CU in a non-terrestrial network (NTN) according to some embodiments of the present disclosure is shown;

[0023] Figure 8 FIG. 1 shows a T for random access channel (RACH) timing according to some embodiments of the present disclosure. wait and T serve A flowchart of an example application of

[0024] Fig. 9 A sequence diagram showing timing enhancement of 4-step RACH for transparent satellites according to some embodiments of the present disclosure;

[0025] Fig.10 A sequence diagram showing timing enhancement upon 4-step RACH failure for a transparent satellite according to some embodiments of the present disclosure;

[0026] Fig.11 A sequence diagram showing timing enhancements for 2-step RACH / non-contention (CF) RACH for transparent satellites according to some embodiments of the present disclosure;

[0027] Fig.12 A sequence diagram showing timing enhancement upon 2-step RACH / CF RACH failure for a transparent satellite according to some embodiments of the present disclosure;

[0028] Fig.13 A sequence diagram showing timing enhancement for 4-step RACH of a regenerative satellite according to some embodiments of the present disclosure;

[0029] Fig.14 A sequence diagram showing timing enhancement upon 4-step RACH failure for regenerating a satellite according to some embodiments of the present disclosure;

[0030] Fig.15 A sequence diagram illustrating timing enhancement for 2-step RACH / CF RACH for a regenerative satellite according to some embodiments of the present disclosure;

[0031] Fig.16 A sequence diagram showing timing enhancement upon failure of 2-step RACH / CF RACH for regenerating a satellite according to some embodiments of the present disclosure;

[0032] Fig.17 A sequence diagram showing timing enhancements for 4-step RACH for a regenerated satellite for gNB DU / CU separation according to some embodiments of the present disclosure;

[0033] Fig.18 A sequence diagram illustrating timing enhancements for 2-step RACH / CF RACH for a regenerated satellite for gNB DU / CU separation according to some embodiments of the present disclosure;

[0034] Fig.19 A flow chart illustrating an example method for timing enhancement in store and forward mode / operation according to some embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0035] 1. Mobile communication technology and environment

[0036] Figure 1 An example wireless communication network and / or system 100 is shown in which the techniques disclosed herein may be implemented according to some embodiments of the present disclosure. In the discussion that follows, the wireless communication network 100 may be any wireless network, such as a cellular network or a narrowband Internet of Things (NB-IoT) network, and is referred to herein as "network 100." Such an example network 100 includes a base station 102 (hereinafter referred to as "BS 102"; also referred to as a wireless communication node) and a user equipment device 104 (hereinafter referred to as "UE 104"; also referred to as a wireless communication device) that may communicate with each other via a communication link 110 (e.g., a wireless communication channel), and a cluster of cells 126, 130, 132, 134, 136, 138, and 140 covering a geographic area 101. In Figure 1 1, BS 102 and UE 104 are contained within the respective geographic boundaries of cell 126. Each of the other cells 130, 132, 134, 136, 138, and 140 may include at least one base station operating with its allocated bandwidth to provide adequate wireless coverage to its intended users.

[0037] For example, BS 102 may operate on an allocated channel transmission bandwidth to provide adequate coverage to UE 104. BS 102 and UE 104 may communicate via downlink radio frames 118 and uplink radio frames 124, respectively. Each radio frame 118 / 124 may be further divided into subframes 120 / 127, which may include data symbols 122 / 128. In the present disclosure, BS 102 and UE 104 are described herein as non-limiting examples of "communication nodes", which may generally practice the methods disclosed herein. According to various embodiments of the present solution, such communication nodes may be capable of wireless and / or wired communication.

[0038] Figure 2 A block diagram of an example wireless communication system 200 for transmitting and receiving wireless communication signals (e.g., OFDM / OFDMA signals) according to some embodiments of the present solution is shown. The system 200 may include components and elements configured to support known or conventional operating features that need not be described in detail herein. In one illustrative embodiment, as described above, the system 200 may be used in applications such as Figure 1 The wireless communication environment 100 may be used to communicate (eg, transmit and receive) data symbols.

[0039] The system 200 generally includes a base station 202 (hereinafter referred to as "BS 202") and a user equipment device 204 (hereinafter referred to as "UE 204"). The BS 202 includes a BS (base station) transceiver module 210, a BS antenna 212, a BS processor module 214, a BS memory module 216, and a network communication module 218, each of which is coupled to and interconnected with each other via a data communication bus 220 as needed. The UE 204 includes a UE (user equipment) transceiver module 230, a UE antenna 232, a UE memory module 234, and a UE processor module 236, each of which is coupled to and interconnected with each other via a data communication bus 240 as needed. The BS 202 communicates with the UE 204 via a communication channel 250, which may be any wireless channel or other medium suitable for data transmission as described herein.

[0040] As will be appreciated by those skilled in the art, the system 200 may also include Figure 2Any number of modules outside the modules shown. It will be appreciated by those skilled in the art that the various illustrative blocks, modules, circuits, and processing logic described in conjunction with the embodiments disclosed herein can be implemented in hardware, computer-readable software, firmware, or any actual combination thereof. In order to clearly illustrate this interchangeability and compatibility of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps are generally described according to their functions. Whether such functions are implemented as hardware, firmware, or software depends on the specific application and design constraints imposed on the entire system. People familiar with the concepts described herein can implement such functions in a manner suitable for each specific application, but such implementation decisions should not be interpreted as limiting the scope of the present disclosure.

[0041] According to some embodiments, the UE transceiver 230 may be referred to herein as an "uplink" transceiver 230, which includes a radio frequency (RF) transmitter and an RF receiver, each including circuitry coupled to an antenna 232. A duplex switch (not shown) may alternatively couple the uplink transmitter or receiver to the uplink antenna in a time duplex manner. Similarly, according to some embodiments, the BS transceiver 210 may be referred to herein as a "downlink" transceiver 210, which includes an RF transmitter and an RF receiver, each including circuitry coupled to an antenna 212. The downlink duplex switch may alternatively couple the downlink transmitter or receiver to the downlink antenna 212 in a time duplex manner. The operation of the two transceiver modules 210 and 230 may be coordinated in time such that the downlink receiver circuit is coupled to the downlink antenna 232 so as to receive transmissions over the wireless transmission link 250 while the downlink transmitter is coupled to the downlink antenna 212. Instead, the operation of the two transceivers 210 and 230 may be coordinated in time such that the downlink receiver coupled to the downlink antenna 212 receives transmissions over the wireless transmission link 250 at the same time as the uplink transmitter coupled to the uplink antenna 232. In some embodiments, tight time synchronization with minimal guard times between changes in duplex direction is provided.

[0042] The UE transceiver 230 and the base station transceiver 210 are configured to communicate via a wireless data communication link 250 and cooperate with an appropriately configured RF antenna arrangement 212 / 232 that can support a specific wireless communication protocol and modulation scheme. In some illustrative embodiments, the UE transceiver 210 and the base station transceiver 210 are configured to support industry standards such as Long Term Evolution (LTE) and emerging 5G standards. However, it should be understood that the present disclosure is not necessarily limited to application to specific standards and related protocols. Instead, the UE transceiver 230 and the base station transceiver 210 can be configured to support alternative or additional wireless data communication protocols, including future standards or variations thereof.

[0043] According to various embodiments, for example, BS202 can be an evolved node B (eNB), a serving eNB, a target eNB, a femtocell or a microcell. In some embodiments, UE 204 can be embodied in various types of user equipment, such as mobile phones, smart phones, personal digital assistants (PDAs), tablet computers, laptop computers, wearable computing devices, etc. Processor modules 214 and 236 can be implemented or completed by a general-purpose processor, content addressable memory, digital signal processor, application specific integrated circuit, field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components or any combination thereof for performing the functions described herein. In this way, the processor can be implemented as a microprocessor, a controller, a microcontroller, a state machine, etc. The processor can also be implemented as a combination of computing devices, such as a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a digital signal processor core, or any other such configuration.

[0044] In addition, the steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be directly embodied in hardware, in firmware, in software modules executed by the processor modules 214 and 236, respectively, or in any practical combination thereof. The memory modules 216 and 234 may be implemented as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. In this regard, the memory modules 216 and 234 may be coupled to the processor modules 210 and 230, respectively, so that the processor modules 210 and 230 can read information from and write information to the memory modules 216 and 234, respectively. The memory modules 216 and 234 may also be integrated into their respective processor modules 210 and 230. In some embodiments, the memory modules 216 and 234 may each include a cache memory for storing temporary variables or other intermediate information during the execution of instructions executed by the processor modules 210 and 230, respectively. Memory modules 216 and 234 may also each include non-volatile memory for storing instructions to be executed by processor modules 210 and 230, respectively.

[0045] The network communication module 218 generally represents the hardware, software, firmware, processing logic and / or other components of the base station 202 that enable bidirectional communication between the base station transceiver 210 and other network components and communication nodes configured to communicate with the base station 202. For example, the network communication module 218 can be configured to support Internet or WiMAX services. In a typical deployment, but not limited to, the network communication module 218 provides an 802.3 Ethernet interface so that the base station transceiver 210 can communicate with a traditional Ethernet-based computer network. In this way, the network communication module 218 can include a physical interface for connecting to a computer network (e.g., a mobile switching center (MSC)). The terms "configured for", "configured to", and combinations thereof used herein for a specific operation or function refer to a device, component, circuit, structure, machine, signal, etc. that is physically constructed, programmed, formatted, and / or arranged to perform a specific operation or function.

[0046] The Open Systems Interconnection (OSI) model (referred to herein as the "Open Systems Interconnection Model") is a conceptual and logical layout that defines network communications used by systems (e.g., wireless communication devices, wireless communication nodes) that are open to interconnection and communication with other systems. The model is divided into seven subcomponents or layers, each representing a conceptual set of services provided to the layers above and below it. The OSI model also defines a logical network and effectively describes computer packet transmission by using different layer protocols. The OSI model may also be referred to as a seven-layer OSI model or a seven-layer model. In some embodiments, the first layer may be a physical layer. In some embodiments, the second layer may be a medium access control (MAC) layer. In some embodiments, the third layer may be a radio link control (RLC) layer. In some embodiments, the fourth layer may be a packet data convergence protocol (PDCP) layer. In some embodiments, the fifth layer may be a radio resource control (RRC) layer. In some embodiments, the sixth layer may be a non-access (NAS) layer or an Internet Protocol (IP) layer, and the seventh layer is another layer.

[0047] Various exemplary embodiments of the present solution are described below with reference to the accompanying drawings to enable a person of ordinary skill in the art to make and use the present solution. It is apparent to a person of ordinary skill in the art that, after reading this disclosure, various changes or modifications may be made to the examples described herein without departing from the scope of the present solution. Therefore, the present solution is not limited to the exemplary embodiments and applications described and illustrated herein. In addition, the specific order or hierarchy of steps in the methods disclosed herein are merely exemplary methods. Based on design preferences, the specific order or hierarchy of steps of the disclosed methods or processes may be rearranged while remaining within the scope of the present solution. Therefore, a person of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or actions in a sample order, and unless otherwise expressly stated, the present solution is not limited to the specific order or hierarchy presented.

[0048] 2. Systems and methods for timing enhancement in store and forward mode

[0049] In non-terrestrial networks (NTNs), large delays may occur due to the long propagation distances involved in the information exchange between user equipment (UE) and base stations (BS). In addition, in store and forward mode, larger delays may occur when the satellite moves again (e.g., along an orbital path) to the UE for signaling or information exchange. In order to address the challenges posed by large delays and achieve uplink synchronization, it may be beneficial to implement timing enhancements (e.g., adjustments) to the random access procedure. In addition, it is important to note that the timing enhancements in the random access channel (RACH) procedure may vary due to the specific satellite architecture / type, e.g., transparent and regenerative architectures, and the type of RACH employed in the system. Therefore, the present disclosure describes various timing enhancements to the RACH procedure for transparent and regenerative satellites with store and forward mode in NTNs.

[0050] Figure 3 A schematic diagram illustrating operation in a store and forward mode in a non-terrestrial network (NTN) according to some embodiments of the present disclosure is shown. Figure 3 The structure of the store and forward mode in the NTN is shown. The link between the UE and the satellite can be a service link. The link between the gateway and the satellite can be a feeder link and can be shared by all UEs. During step A, there can only be a connected service link between the UE and the satellite (for example, the satellite can only work / communicate on a service link without a feeder link connection / communication). During step B, there can only be a connected feeder link between the gateway and the satellite (for example, the satellite can only work / communicate on a feeder link without a service link connection / communication). When the satellite moves between step A and step B, signaling / data exchange can be performed by using the satellite's ability to perform store and forward.

[0051] Figure 4 Schematic diagram showing modification operations in a store and forward mode between satellites according to some embodiments of the present disclosure. Figure 4 As shown, the modification operation in the storage and forwarding between satellites can be a specific method, which can realize the connection between the UE and the gateway via the inter-satellite link. For example, when the feeder link between satellite A and the gateway is disabled or not working, the inter-satellite link between satellite A and satellite B can be established to maintain the communication connection between the UE and the gateway.

[0052] Figure 5 A schematic diagram of a transparent satellite in a non-terrestrial network (NTN) is shown according to some embodiments of the present disclosure. Figure 6 A schematic diagram of a regenerative satellite in a non-terrestrial network (NTN) according to some embodiments of the present disclosure is shown. Figure 5 and 6 As shown, satellite payloads can be divided into transparent payloads and regenerative payloads. For transparent satellites, the satellite can be considered as an analog radio frequency (RF) repeater that can implement / perform frequency conversion and RF amplification in the uplink and downlink directions. For regenerative satellites, base station functions can be on the satellite, which can implement / perform / include RF filtering, frequency conversion and amplification as well as demodulation / decoding, switching and / or routing and / or coding / modulation. In particular, for gNB DU / CU splitting in regenerative satellites, some higher layer functions (e.g., radio resource control (RRC)) can be split into gNB-CU (e.g., separated from the satellite). Figure 7 A schematic diagram of such a gNB-CU based regenerative satellite in a non-terrestrial network (NTN) according to some embodiments of the present disclosure is shown.

[0053] Based on the above introduction, considering transparent and regenerative satellite modes for (eg, supporting / facilitating) store and forward operations in NTNs, timing enhancement of RACH procedures may be performed for different scenarios.

[0054] Figure 8 FIG. 1 shows a T for random access channel (RACH) timing according to some embodiments of the present disclosure. wait and T serve Flowchart of an example application. wait The waiting duration may include at least one of: (a) a period duration of the satellite orbit, (b) a processing duration at the gateway, (c) a round-trip propagation delay between the satellite and the gateway, (d) a round-trip propagation delay between the satellite and the UE, or (e) a timing offset.

[0055] For T serveThe service duration may be a maximum duration during which the UE is covered by the satellite (e.g., cellular coverage received from the satellite). In order to determine whether the remaining portion of the service duration (or within the service duration) is sufficient / available, the determination method may be summarized as determining / detecting the following: (1) the current elevation angle is less than an elevation angle threshold; (2) the reference signal received power (RSRP) at the current time is higher than an RSRP threshold; (3) the distance at the current time is less than a threshold of the distance between the UE and the satellite; or (4) the remaining (partial) service duration is greater than the sum of a predetermined duration (e.g., K) and a round trip propagation time (RTT), wherein the remaining service duration may be determined by the current coordinated universal time (UTC), T serve The UTC time when the timer starts is T serve (For example, T serve -(T current,UTC -T startofTimer,UTC ) or the difference between the service duration and the current service duration (e.g., T serve -T current,serve ). k is the scheduled duration of DCI scheduled Msg3. RTT is the maximum round-trip time between UE and satellite.

[0056] For a UE with a global navigation satellite system (GNSS) module, a timing advance (TA) may be calculated by the UE's position and satellite ephemeris to delay / shift the random access response (RAR) window.

[0057] For UEs without GNSS modules, the range of the RAR window with the maximum RTT between the UE and the satellite is extended to cover the precise round-trip delay.

[0058] Implementation Example 1: Timing enhancement of RACH based on waiting duration and service duration for transparent satellite mode

[0059] Case 1-1: For a transparent satellite in store and forward mode (e.g., the satellite stores synchronization signal blocks (SSBs), system information blocks (SIBs), T wait , T serve , and then forwarded to the UE later), a timing enhancement of 4 steps of random access can be specified. Fig. 9 A sequence diagram illustrating timing enhancement (eg, adjustment) of a 4-step RACH for a transparent satellite according to some embodiments of the present disclosure is shown. Fig.10 A sequence diagram illustrating timing enhancement upon 4-step RACH failure for a transparent satellite according to some embodiments of the present disclosure is shown.

[0060] Before the random access process, the satellite can send the stored synchronization signal block (SSB), system information (SI), waiting duration T to the UE.wait and service duration T serve The wait duration can be indicated using the following options:

[0061] Option 1: As a waiting duration T wait The constant value, T wait ≥T period , ensuring successful transmission and / or processing of Msg1 according to network configuration (e.g., physical random access channel (PRACH) timing, preamble index at minimum reference signal received power (RSRP) threshold, elevation angle threshold, and / or distance threshold). The waiting duration may include at least one of the following: a period duration of a satellite orbit, a processing duration at a gateway, a round-trip propagation delay between a satellite and a gateway, or a round-trip propagation delay between a satellite and a UE.

[0062] Option 2: As an offset and constant value of the wait duration, where Twait = ΔT + T wait,initial Each value of the offset may be mapped with a corresponding RSRP threshold, elevation threshold, and / or distance threshold. For example, the following Table 1 may be configured.

[0063] Table 1

[0064]

[0065] At time t1, the UE may send Msg1 to the satellite and may start waiting for a duration of T wait The UE may calculate and store a first timing advance (TA1) (eg, a propagation delay between the UE and the satellite).

[0066] At time t2, when the satellite passes by the gateway (eg, along the satellite's orbital path), the satellite may forward the stored Msg1 to the gateway.

[0067] At time t3, if Msg1 is correctly decoded at the gateway, the gateway can send Msg2 to the satellite.

[0068] At time t4, when the waiting duration T wait When the timer of t1 expires, the satellite may forward the stored Msg2 to the UE. The UE may receive Msg2 at / within a random access response (RAR) window adjusted by the delay of the sum of the first timing advance (TA1) and the second timing advance (TA2). TA1 may be the calculated propagation delay stored by the UE at time t1. TA2 may be the propagation delay between the UE and the satellite calculated at time t4. Otherwise, as Fig.10As shown, if the UE does not receive Msg2, the UE may restart random access after an offset of ΔT that can be mapped to a higher uplink (UL) coverage. Waiting duration T wait The timer can also be restarted. For example, according to the above mapping table, random access can be restarted with a delay of a larger time offset at a higher reference signal received power (RSRP), a higher elevation angle or a lower distance.

[0069] At time t5, the UE may send Msg3 with a timing advance of the sum of TA1+TA2. TA2 may be the propagation delay between the UE and the satellite. wait When / after the timer of the UE expires, after a delay of the third timing advance and the fourth timing advance (e.g., TA3+TA4), the UE may wait for Msg4 within the contention resolution window (e.g., before the contention resolution timer expires). TA3 and TA4 may be propagation delays between the UE and the satellite, which are calculated when the UE sends Msg3 and receives Msg4, respectively.

[0070] At time t6, the satellite may forward the stored Msg3 to the gateway and may perform conflict detection and permanent cell radio network temporary identifier (C-RNTI) allocation.

[0071] At time t7, when Msg3 is correctly decoded, the network can send Msg4 to the satellite.

[0072] At time t8, when the satellite passes by the UE, the satellite can forward the stored Msg4 to the UE. If the Msg4 decoding is successful, the random access can be completed. Otherwise, the service duration T serve After waiting for a new offset within ΔT, the UE may restart random access with higher UL coverage.

[0073] Case 1-2: For 2-step random access or non-contention random access in transparent satellite mode, the waiting duration T wait and service duration T serve The application is feasible / supported. Fig.11 A sequence diagram illustrating timing enhancement of 2-step RACH / control function (CF) RACH for transparent satellites according to some embodiments of the present disclosure is shown. Fig.12 A sequence diagram illustrating timing enhancement upon 2-step RACH / CF RACH failure for a transparent satellite according to some embodiments of the present disclosure is shown.

[0074] Before starting / performing the random access procedure, the satellite sends the stored synchronization signal block (SSB), system information (SI), and waiting duration T to the UE. waitand / or service duration T serve The wait duration can be indicated using the following options.

[0075] Option 1: As a waiting duration T greater than the period duration of the satellite orbit wait The constant value, T wait ≥T period , at least ensure that Msg1 / MsgA is successfully sent / processed under the network configuration of the minimum higher reference signal received power (RSRP) threshold, elevation angle threshold, or distance threshold.

[0076] Option 2: As an offset and constant value of the wait duration, where Twait = ΔT + T wait,initial Different offset values ​​may be mapped with corresponding values ​​of RSRP threshold, elevation threshold and / or distance threshold. The time offset may be less than the service duration (eg, ΔT≤T serve ). wait , T serve and T wait,initial The UE may be indicated via SIB signaling. For the mapping relationship, the following Table 2 may be configured.

[0077] Table 2

[0078]

[0079] At time t1, the UE may send Msg1 / MsgA to the satellite and may start waiting for a duration of T wait Timer / used to wait for duration T wait The UE may calculate and store a first timing advance (TA1) (eg, a propagation delay between the UE and the satellite).

[0080] At time t2, when the satellite passes by the gateway, the satellite can forward the stored Msg1 / MsgA to the gateway.

[0081] At time t3, if Msg1 / MsgA is decoded correctly, the gateway can send Msg2 / MsgB to the satellite.

[0082] At time t4, when the waiting duration T wait When the timer of t4 expires, the satellite may forward the stored Msg2 / MsgB to the UE. The UE may receive Msg2 at a random access response (RAR) window with a delay of (or offset / adjusted by) the sum of the first timing advance (TA1) and the second timing advance (TA2). TA2 may be the propagation delay between the UE and the satellite calculated at time t4. Otherwise, as Fig.12As shown, if the UE does not receive Msg2 / MsgB, the UE can restart random access by mapping to an offset ΔT of higher UL coverage. Waiting duration T wait The timer of can also be restarted. For example, according to the above mapping table, random access can be restarted with a delay of a larger time offset at a higher RSRP, a higher elevation angle or a lower distance.

[0083] For the case where the preamble decoding is successful but Msg3 of MsgA fails, the waiting duration can be used for the fallback procedure of 4-step RACH.

[0084] Implementation Example 2: Timing enhancement of RACH is based on waiting duration and service time of a regenerative satellite with an onboard gNB

[0085] Case 2-1: For a regenerative satellite with an onboard gNB, the timing enhancement of the 4-step random access procedure can be performed as follows. Fig.13 A sequence diagram illustrating timing enhancement for 4-step RACH for a regenerative satellite (e.g., with gNB / satellite processed payload) in accordance with some embodiments of the present disclosure is shown. Fig.14 A sequence diagram illustrating timing enhancement upon 4-step RACH failure for regenerating a satellite (e.g., with a gNB / satellite processed payload) in accordance with some embodiments of the present disclosure is shown.

[0086] Before the random access process begins, the satellite can send a synchronization signal block (SSB), system information (SI), and a waiting duration T to the UE. wait and / or service duration T serve The wait duration can be indicated using the following options.

[0087] Option 1: As a waiting duration T wait The constant value, T wait ≥T period , ensuring that Msg1 is successfully transmitted and / or processed under the network configuration of the minimum RSRP threshold, elevation angle threshold or distance threshold.

[0088] Option 2: As an offset and constant value of the wait duration, where Twait = ΔT + T wait,initia l , the offset value may be mapped with the corresponding value of the RSRP threshold, the elevation threshold and / or the distance threshold. For example, the following Table 3 may be configured.

[0089] Table 3

[0090]

[0091] At time t1, the UE may send Msg1 to the satellite, and may wait for Msg2 at / within the RAR window with a delay of 2*TA (eg, TA may be the calculated propagation delay between the UE and the satellite).

[0092] At time t2, if Msg1 is correctly decoded by the airborne base station, the UE can receive Msg2. Otherwise, the UE can receive Msg2 according to the above mapping table by using a time offset (e.g., a higher RSRP; △T≤T serve ), higher elevation angle or lower distance to restart random access.

[0093] At time t3, the UE may send Msg3 to the satellite and may wait for Msg4 within the contention resolution timer after a delay of 2*TA (e.g., adjusted / delayed / offset by the delay). TA may be the propagation delay between the UE and the satellite calculated at time t3.

[0094] At time t4, if Msg4 is successfully decoded, random access can be completed. Otherwise, the UE can complete the random access by serve Use a larger offset △T within 1 second and restart random access with higher UL coverage. If △T>T serve , the UE can restart and delay random access for the configured waiting duration T wait .

[0095] When T serve When the timer expires, the UE may interrupt its transmission.

[0096] Case 2-2: For regenerative satellite, gNB processed payload, timing enhancement of 2-step random access procedure or non-contention random access procedure, waiting duration T wait and service duration T serve The application is also feasible. Fig.15 A sequence diagram illustrating timing enhancement for 2-step RACH / CF RACH for regenerative satellite (e.g., gNB / satellite processed payload) according to some embodiments of the present disclosure is shown. Fig.16 A sequence diagram illustrating timing enhancement upon failure of 2-step RACH / CF RACH for regenerating satellite, gNB-handled payload in accordance with some embodiments of the present disclosure is shown.

[0097] Before the random access process starts / occurs, the satellite may send a synchronization signal block (SSB), system information (SI), a waiting duration T to the UE. wait and / or service duration T serve The wait duration can be indicated using the following options.

[0098] Option 1: As a waiting duration T greater than the period duration of the satellite orbit wait The constant value, T wait ≥T period , which can ensure that Msg1 / MsgA is successfully sent under the network configuration of the minimum RSRP threshold, elevation angle threshold or distance threshold.

[0099] Option 2: As an offset and constant value of the wait duration, where Twait = ΔT + T wait,initial , each value of the offset can be mapped with a corresponding value of the RSRP threshold, the elevation threshold, and / or the distance threshold. The time offset can be less than the service duration (e.g., ΔT≤T serve ). For example, the following Table 4 can be configured.

[0100] Table 4

[0101]

[0102] At time t1, the UE may send Msg1 / MsgA to the satellite, and may wait for Msg2 / MsgB at / within the RAR window with a delay of 2*TA. TA may be the propagation delay between the UE and the satellite.

[0103] At time t2, if Msg1 / MsgA is correctly decoded by the airborne base station, the UE can receive Msg2 / MsgB. Otherwise, the UE can use the above mapping table (where △T≤T serve ) Restart random access with higher UL coverage by using a time offset (e.g., higher RSRP), a higher elevation angle, or a lower distance. If ΔT>T serve , the UE may restart and delay random access by the configured waiting duration T wait .

[0104] Implementation Example 3: Timing enhancement of RACH based on waiting duration and service duration for regenerative satellite with onboard gNB-DU

[0105] Case 3-1: For regenerative satellite, gNB-DU processed payload, timing enhancement of 4-step random access can be specified. Fig.17 A sequence diagram showing timing enhancements for 4-step RACH for regenerative satellites with gNB DU / CU splitting according to some embodiments of the present disclosure is shown. For CU / DU splitting, the UE may wait for a waiting duration T wait , to receive Radio Resource Control (RRC) signaling from the gNB Centralized Unit (gNB-CU). The following procedures may be modified.

[0106] Before the random access process, the satellite can send the stored synchronization signal block (SSB), system information (SI), waiting duration T to the UE. wait and / or service duration T serve The wait duration can be indicated using the following options.

[0107] Option 1: Wait for duration T wait The constant value, T wait ≥T period , it can ensure that Msg1 is successfully transmitted and / or processed under the network configuration (e.g., PRACH opportunity, preamble index) of the minimum RSRP threshold, elevation threshold, or distance threshold. The waiting duration may include at least one of the following: the period duration of the satellite orbit, the processing duration at the gateway, or the round-trip propagation delay between the satellite and the gateway, or the round-trip propagation delay between the satellite and the UE.

[0108] Option 2: As an offset and constant value of the wait duration, where Twait = ΔT + T wait,initial , the offset value can be mapped with the RSRP threshold, the elevation threshold and the distance threshold. For example, the following Table 5 can be configured.

[0109] Table 5

[0110]

[0111] At time t1, the UE can send Msg1 to the satellite and start the duration T wait The UE may calculate and store TA1 (eg, the propagation delay between the UE and the satellite) to wait for Msg2.

[0112] At time t2, if Msg1 is decoded correctly, the gNB centralized unit (gNB-CU) can send radio resource control (RRC) information (e.g., ra-ResponseWindow) to the satellite gNB distributed unit (gNB-DU).

[0113] At time t3, when the waiting duration T waitWhen the timer expires, the satellite may forward the stored ra-ResponseWindow and RRC information of Msg2 to the UE. The UE may receive Msg2 at the RAR window with a delay of the sum of TA1+TA2. TA1 may be the calculated propagation delay stored by the UE at time t1. TA2 may be the propagation delay between the UE and the satellite calculated at time t3. Otherwise, if the UE does not receive Msg2, the UE may restart random access with a higher UL coverage. For example, according to the mapping table above, random access may be restarted with a delay of a larger time offset at a higher RSRP, a higher elevation angle, or a lower distance.

[0114] At time t4, the UE can send Msg3 with a timing advance of the sum of TA1+TA2. TA2 can be the propagation delay between the UE and the satellite. When the waiting duration T wait When the timer expires, the UE may wait for Msg4 within the contention resolution timer after a delay of TA3+TA4. TA3 and TA4 may be propagation delays between the UE and the satellite, which are calculated when the UE sends Msg3 and receives Msg4, respectively.

[0115] At time t5, when Msg3 is decoded correctly, the gNB-CU can send the RRC information of ra-ContentionResolutionTimer to the satellite gNB-DU.

[0116] At time t6, when the satellite passes by the UE, the satellite can forward the stored ra-ContentionResolutionTimer and the RRC information of Msg4 to the UE. If the Msg4 decoding is successful, the random access can be completed. Otherwise, the service duration T serve Within ΔT, the UE may restart random access with a new offset ΔT and a higher UL coverage.

[0117] Case 3-2: For regenerative satellite (e.g. gNB-DU / satellite-processed payload), a timing enhancement for 2-step random access or non-contention random access may be specified. Waiting duration T wait and service duration T serve The application is feasible. Fig.18 A sequence diagram illustrating timing enhancement for 2-step RACH / CF RACH for regenerative satellite with gNB DU / CU splitting in accordance with some embodiments of the present disclosure is shown.

[0118] Before the random access process, the satellite can send the stored SSB, SI, and waiting duration T to the UE. wait and / or service duration T serveThe wait duration can be indicated using the following options.

[0119] Option 1: As a waiting duration T greater than the satellite orbit period duration wait The constant value, T wait ≥T period , at least ensuring successful transmission and / or processing of Msg1 / MsgA under a network configuration of a minimum higher reference signal received power (RSRP) threshold, elevation angle threshold, or distance threshold.

[0120] Option 2: As an offset and constant value of the wait duration, where Twait = ΔT + T wait,initial The offset value can be mapped with the corresponding value of the RSRP threshold, the elevation threshold and / or the distance threshold. The time offset can be less than the service duration (e.g., ΔT≤T serve ). For example, the following Table 6 can be configured.

[0121] Table 6

[0122]

[0123] At time t1, the UE may send Msg1 / MsgA to the satellite gNB-DU. The UE may start the duration T wait The UE may calculate and store TA1 (eg, the propagation delay between the UE and the satellite) by setting a timer to wait for Msg2 / MsgB.

[0124] At time t2, when the satellite passes by the gNB-CU, the gNB-CU can send RRC information of RAR-ResponseWindow or MsgB-ResponseWindow to the satellite gNB-DU.

[0125] At time t3, if Msg1 / MsgA is decoded correctly, the satellite gNB-DU can send RAR-ResponseWindow / MsgB-ResponseWindow and RRC information of Msg2 / MsgB to the UE.

[0126] At time t4, when the waiting duration T wait When the timer of t1+t2 expires, the UE may receive Msg2 / MsgB at the RAR window at / after a delay of the sum of TA1+TA2. TA2 may be the propagation delay between the UE and the satellite calculated at time t4. Otherwise, if the UE does not receive Msg2 / MsgB, the UE may restart random access with a higher UL coverage. For example, according to the mapping table above, random access may be restarted with a delay of a larger time offset at a higher RSRP, a higher elevation angle, or a lower distance.

[0127] For the case where the preamble decoding is successful but Msg3 of MsgA fails, the waiting duration can be used for the fallback procedure of 4-step RACH.

[0128] Implementation Example 4: Timing enhancement of RACH based on waiting duration and common TA

[0129] When the UE does not have a global navigation satellite system (GNSS) module, the UE may not be able to calculate the propagation delay between the UE and the satellite (e.g., TA1, TA2), and then a conflict may occur at the random access response (RAR) window. In order to cover the round trip time (RTT) between the UE and the satellite, the expansion of the RAR window helps to eliminate the impact of the maximum RTT differential delay. The extension range of the RAR window can depend on the common TA, as follows.

[0130] (1) When the network is configured with a public TA, it can be used by applying T wait The timing relationship is achieved with a common TA (for all UEs). The extension of the RAR window can be used to cover the maximum RTT differential delay (for all UEs).

[0131] (2) In the absence of a public TA (configured by the network), T wait The application can be used to extend / update the RAR window, contention resolution timer, and large-scale extension of the RAR window to cover the maximum RTT.

[0132] It should be understood that one or more features from the above-mentioned implementation examples are not exclusive of a specific implementation example, but can be combined in any manner (eg, in any priority and / or order, simultaneously or otherwise).

[0133] Fig.19 A flow chart of a method 1900 for timing enhancement in a store and forward mode is shown. The method 1900 may be used in conjunction with Figure 1 and Figure 2 The method 1900 may be implemented by any one or more components and devices described in detail. In general, in some embodiments, the method 1900 may be performed by a communicating wireless node. Depending on the embodiment, additional, fewer or different operations may be performed in the method 1900. At least one aspect of the operation involves a system, method, apparatus or computer-readable medium.

[0134] A wireless communication node (e.g., a base station (BS), which may be part of a regenerated satellite or, for example, separate from the satellite) may configure a time duration (e.g., T ) indicating the next service period to the satellite. wait ) and the duration of the service period of the satellite (e.g., T serve). The wireless communication node may send the waiting duration and the service duration (an indication thereof) for use by a wireless communication device (e.g., a user equipment (UE)) during a random access procedure. In some embodiments, the wireless communication node (e.g., a regenerative satellite) may send the waiting duration and the service duration directly to the UE. In some embodiments, the wireless communication node (e.g., a BS) may send the waiting duration and the service duration to the UE via a satellite (e.g., a transparent satellite). The random access procedure may include a 4-step random access procedure, or a 2-step random access procedure or a non-contention random access procedure.

[0135] In some embodiments, the waiting duration may include at least one of the following: the duration of one orbital cycle of a satellite, the processing duration at a wireless communication node, the round-trip propagation time between a satellite and a wireless communication node, the round-trip propagation time between a satellite and a wireless communication device, a fixed value, or the sum of a fixed value and an offset value.

[0136] In some implementations, the wireless communication node may send the waiting duration and the service duration to the satellite via at least one of: master information block (MIB) signaling, system information block (SIB) signaling, or radio resource control (RRC) signaling. The satellite may store the waiting duration and the service duration. The satellite may send the waiting duration and the service duration to the wireless communication device.

[0137] In some implementations, during a first instance of the service duration, the wireless communication device may wait for a first instance of the period to start (eg, Fig. 9 The satellite may respond to the first instance of the waiting period expiring (e.g., Fig. 9 The wireless communication device may receive the Msg2 or MsgB from the satellite in a random access response (RAR) window having a delay including the sum of the first timing advance (TA1) and the second timing advance (TA2). During the second instance of the service duration, the wireless communication device may receive the Msg2 or MsgB at the start time of the second instance of the waiting period (e.g., Fig. 9 At t5 in the contention resolution window, the wireless communication device sends Msg3 having a timing advance including the sum of TA1 and TA2. After the second instance of the waiting period expires, the wireless communication device can monitor after a delay including the sum of the third timing advance (TA3) and the fourth timing advance (TA4) to receive Msg4 in the contention resolution window.

[0138] In some embodiments, the wireless communication device may determine to send Msg1, Msg3, or MsgA if (e.g., under the following conditions) at least one of the following occurs: the calculated elevation angle is greater than an elevation angle threshold, the measured reference signal received power (RSRP) is higher than an RSRP threshold, the calculated distance is less than a distance threshold between the wireless communication device and the satellite, or the remaining portion of the service duration calculated by the wireless communication device is greater than the sum of a predetermined duration (e.g., K, a predetermined duration of DCI predetermined Msg3) and a round-trip propagation time between the satellite and the wireless communication device.

[0139] In some embodiments, TA1 may be a start time of a first instance of a waiting period (eg, Fig. 9 TA2 can be the propagation delay calculated when the satellite sends Msg2 or MsgB to the wireless communication device (for example, Fig. 9 TA3 may be the propagation delay between the wireless communication device and the satellite when the wireless communication device sends Msg3 (e.g., Fig. 9 TA4 may be the propagation delay between the wireless communication device and the satellite when the wireless communication device receives Msg4 (e.g., Fig. 9 The propagation delay between the wireless communication device and the satellite is calculated using t8).

[0140] In some implementations, when the waiting period expires, if the wireless communication device does not receive (e.g., unsuccessfully) Msg2, Msg4, or MsgB, then after a defined offset time (ΔT, e.g., mapped to a higher uplink (UL) coverage), the wireless communication device may resend Msg1, Msg3, or MsgA to the satellite at the start time of another instance of the waiting period.

[0141] In some embodiments, the wireless communication node on the satellite sends the wait duration and the service duration to the wireless communication device. During the first instance of the service duration, the wireless communication device can wait for the first instance of the service period at the start time (e.g., Fig.13 The satellite may send Msg2 or MsgB to the wireless communication device (e.g., Fig.13 In response to the expiration of the first instance of the waiting period, the wireless communication device may receive Msg2 from the satellite in a random access response (RAR) window having a delay including two times the timing advance (TA). During a second instance of the service duration, the wireless communication device may receive Msg2 at the start time of the second instance of the waiting period (e.g., Fig.13After the second instance of the waiting period expires, the wireless communication device may monitor after a delay including twice TA to receive Msg4 in the contention resolution window. TA may be a propagation delay between the wireless communication device and the satellite. When the waiting period expires, if the wireless communication device does not receive Msg2, Msg4, or MsgB, then after a defined offset time (ΔT, e.g., mapped to a higher uplink (UL) coverage), the wireless communication device may resend Msg1, Msg3, or MsgA to the satellite at the start time of another instance of the waiting period.

[0142] In some embodiments, the wireless communication node (e.g., gNB-CU) may send the wait duration and the service duration (an indication thereof) to the satellite. The satellite may store the wait duration and the service duration. The satellite may send the wait duration and the service duration to the wireless communication device. During the first instance of the service duration, the wireless communication device may, at the start time of the first instance of the wait period (e.g., Fig.17 The satellite may respond to the first instance of the waiting period (e.g., Fig.17 The wireless communication device may receive the Msg2 or MsgB and the first radio resource control (RRC) information from the satellite in / during a random access response (RAR) window having a delay including the sum of the first timing advance (TA1) and the second timing advance (TA2). During the second instance of the service duration, the wireless communication device may wait for the second instance of the waiting period at a start time (e.g., Fig.17 At t4 in the contention resolution window, the wireless communication device may send Msg3 having a timing advance of / after the sum of TA1 and TA2. After the second instance of the waiting period expires, the wireless communication device may monitor after a delay of the sum of the third timing advance (TA3) and the fourth timing advance (TA4) to receive Msg4 and the second RRC information in / during the contention resolution window.

[0143] In some embodiments, TA1 may be a start time of a first instance of a waiting period (eg, Fig.17 TA2 can be the propagation delay calculated when the satellite sends Msg2 or MsgB to the wireless communication device (for example, Fig.17 TA3 may be the propagation delay between the wireless communication device and the satellite calculated / determined (e.g., using the GNSS module of the wireless communication device) when the wireless communication device sends Msg3 (e.g., Fig.17TA4 may be a propagation delay between the wireless communication device and the satellite calculated / determined (e.g., using a GNSS module of the wireless communication device) at t4 in the wireless communication device. TA4 may be a propagation delay between the wireless communication device and the satellite calculated when the wireless communication device receives Msg4. When the waiting period expires, if the wireless communication device does not receive Msg2, Msg4, or MsgB, then after a defined offset time (ΔT, e.g., mapped to a higher uplink (UL) coverage), the wireless communication device may resend Msg1, Msg3, or MsgA to the satellite at the start time of another instance of the waiting period (e.g., attempt to send another Msg1, Msg3, or MsgB). The wireless communication device may receive Msg2 or MsgB from the satellite in a RAR window that is extended to include a common timing advance of multiple wireless communication devices (e.g., configured / determined by the wireless communication node) or a maximum round-trip propagation delay between the wireless communication device and the satellite. The wireless communication device may monitor to receive Msg4 within a contention resolution window that is extended / modified to include a common timing advance or a maximum round-trip propagation delay between the wireless communication device and the satellite.

[0144] In some embodiments, a wireless communication device (e.g., a UE) may receive a configuration to be used during a random access procedure, the configuration including a wait duration (e.g., T ) indicating the duration of the next service period of the satellite. wait ) and a service duration indicating the duration of the satellite's service period (e.g., T serve ). The waiting duration and the service duration may be configured by a wireless communication node (eg, a BS, which may be part of a regenerative satellite, for example).

[0145] Although various embodiments of the present solution have been described above, it should be understood that they are given only by way of example and not by way of limitation. Similarly, various figures may depict example architectures or configurations, which are provided to enable those of ordinary skill in the art to understand the exemplary features and functions of the present solution. However, these personnel will understand that the present solution is not limited to the example architectures or configurations shown, but may be implemented using a variety of alternative architectures and configurations. In addition, as will be understood by those of ordinary skill in the art, one or more features of an embodiment may be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments.

[0146] It should also be understood that any reference to an element herein using names such as "first," "second," etc. does not generally limit the number or order of those elements. Rather, these names may be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to a first and a second element does not indicate that only two elements may be used, or that the first element must be located before the second element in some manner.

[0147] In addition, those of ordinary skill in the art will appreciate that information and signals may be represented using any of a variety of different techniques. For example, data, instructions, commands, information, signals, bits, and symbols that may be referenced in the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0148] Those of ordinary skill in the art will further understand that any of the various illustrative logical blocks, modules, processors, devices, circuits, methods, and functions described in conjunction with the aspects disclosed herein may be implemented by electronic hardware (e.g., digital implementation, analog implementation, or a combination of both), firmware, various forms of programs or design codes containing instructions (for convenience, referred to herein as "software" or "software modules"), or any combination of these technologies. In order to clearly illustrate this interchangeability of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functions. Whether such functionality is implemented as hardware, firmware, or software, or a combination of these technologies, depends on the specific application and the design constraints imposed on the overall system. A skilled person may implement the described functionality in various ways for each specific application, but such implementation decisions will not cause a departure from the scope of the present disclosure.

[0149] In addition, it will be understood by those of ordinary skill in the art that the various illustrative logic blocks, modules, devices, components, and circuits described herein may be implemented or performed within an integrated circuit (IC) including a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, or any combination thereof. The logic blocks, modules, and circuits may further include antennas and / or transceivers to communicate with various components within a network or within a device. A general purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other suitable configuration to perform the functions described herein.

[0150] If implemented in software, the functions may be stored as one or more instructions or codes on a computer-readable medium. Therefore, the steps of the method or algorithm disclosed herein may be implemented as software stored on a computer-readable medium. Computer-readable media include computer storage media and communication media, and communication media include any media that enables a computer program or code to be transferred from one place to another. The storage medium can be any available medium that a computer can access. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, and any other medium that can be used to store the desired program code in the form of instructions or data structures and can be accessed by a computer.

[0151] As used herein, the term "module" refers to software, firmware, hardware, and any combination of these elements to perform the relevant functions described herein. In addition, for the purpose of discussion, various modules are described as discrete modules; however, it is obvious to a person skilled in the art that two or more modules can be combined to form a single module that performs the relevant functions according to the implementation of the present solution.

[0152] In addition, memory or other storage and communication components may be used in the implementation of the present solution. It should be understood that, for the sake of clarity, the above description has described the implementation of the present solution with reference to different functional units and processors. However, it will be apparent that any appropriate distribution of functions between different functional units, processing logic elements or domains may be used without departing from the present solution. For example, functions illustrated as being performed by separate processing logic elements or controllers may be performed by the same processing logic element or controller. Therefore, references to specific functional units are only references to suitable devices for providing the described functions, rather than indicating a strict logical or physical structure or organization.

[0153] Various modifications to the embodiments described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as described in the following claims.

Claims

1. A method comprising: The wireless communication node configures a wait duration indicating a duration of a next service period to a satellite and a service duration indicating a duration of a service period of said satellite; as well as The wireless communication node sends the wait duration and the service duration for use by a wireless communication device during a random access procedure.

2. The method according to claim 1, wherein: The random access procedure includes a 4-step random access procedure, or a 2-step random access procedure or a non-contention random access procedure.

3. The method according to claim 1, wherein: The waiting duration includes at least one of the following: the duration of one orbital period of the satellite; duration of processing at the wireless communication node; round-trip propagation time between the satellite and the wireless communication node; round-trip propagation time between the satellite and the wireless communication device; Fixed value; The sum of the fixed value and the offset value.

4. The method according to claim 1, comprising: The wireless communication node sends the waiting duration and the service duration to the satellite via at least one of: master information block MIB signaling, system information block SIB signaling, and radio resource control RRC signaling; The satellite stores the waiting duration and the service duration, and sends the waiting duration and the service duration to the wireless communication device.

5. The method according to claim 4, wherein: At least one of the following: During a first instance of the service duration, the wireless communication device sends Msg1 or MsgA to the satellite at a start time of the first instance of the waiting period; In response to expiration of the first instance of the waiting period, the satellite sends Msg2 or MsgB to the wireless communication device; The wireless communication device receives the Msg2 or MsgB from the satellite in a random access response RAR window, the window having a delay including a sum of a first timing advance TA1 and a second timing advance TA2; During a second instance of the service duration, the wireless communication device transmits Msg3 at a start time of a second instance of the waiting period, the Msg3 having a timing advance including a sum of the TA1 and the TA2; After expiration of the second instance of the waiting period, the wireless communication device monitors after a delay including the sum of a third timing advance TA3 and a fourth timing advance TA4 to receive Msg4 in a contention resolution window.

6. The method according to claim 5, wherein: The wireless communication device determines to send the Msg1, the Msg3 or the MsgA if at least one of the following occurs: The calculated elevation angle is greater than the elevation angle threshold; The measured reference signal received power RSRP is higher than the RSRP threshold; The calculated distance is less than a distance threshold between the wireless communication device and the satellite; The remaining portion of the service duration calculated by the wireless communication device is greater than a sum of a predetermined duration and a round trip propagation time between the satellite and the wireless communication device.

7. The method according to claim 5, wherein: At least one of the following: The TA1 is a propagation delay calculated by the wireless communication device at the start time of the first instance of the waiting period; The TA2 is a propagation delay between the wireless communication device and the satellite calculated when the satellite transmits the Msg2 or MsgB to the wireless communication device; The TA3 is a propagation delay between the wireless communication device and the satellite calculated when the wireless communication device sends the Msg3; The TA4 is a propagation delay between the wireless communication device and the satellite calculated when the wireless communication device receives the Msg4.

8. The method according to claim 5, wherein: In response to the waiting period expiring, if the wireless communication device does not receive the Msg2, Msg4 or MsgB: After a defined offset time, the wireless communication device retransmits the Msg1, Msg3 or MsgA to the satellite at a start time of another instance of the waiting period.

9. The method according to claim 1, comprising: The wireless communication node on the satellite sends the wait duration and the service duration to the wireless communication device.

10. The method according to claim 9, wherein: At least one of the following: During a first instance of the service duration, the wireless communication device sends Msg1 or MsgA to the satellite at a start time of the first instance of the waiting period; The satellite sends Msg2 or MsgB to the wireless communication device; In response to expiration of the first instance of the waiting period, the wireless communication device receiving a Msg2 from the satellite in a random access response (RAR) window, the window having a delay including two timing advances (TA); During a second instance of the service duration, the wireless communication device sends Msg3 at a start time of a second instance of the waiting period; After expiration of the second instance of the waiting period, the wireless communication device monitors after a delay including twice the TA to receive Msg4 in the contention resolution window.

11. The method according to claim 10, wherein: The TA is the propagation delay between the wireless communication device and the satellite.

12. The method according to claim 10, wherein: In response to the waiting period expiring, if the wireless communication device does not receive the Msg2, Msg4 or MsgB: After a defined offset time, the wireless communication device retransmits the Msg1, Msg3 or MsgA to the satellite at a start time of another instance of the waiting period.

13. The method according to claim 1, comprising: The wireless communication node sends the waiting duration and the service duration to the satellite, The satellite stores the waiting duration and the service duration, and sends the waiting duration and the service duration to the wireless communication device.

14. The method according to claim 13, wherein: At least one of the following: During a first instance of the service duration, the wireless communication device sends Msg1 or MsgA to the satellite at a start time of the first instance of the waiting period; In response to expiration of the first instance of the waiting period, the satellite sends Msg2 or MsgB to the wireless communication device; The wireless communication device receives the Msg2 or MsgB and the first radio resource control RRC information from the satellite in a random access response RAR window, the window having a delay including a sum of a first timing advance TA1 and a second timing advance TA2; During a second instance of the service duration, the wireless communication device transmits Msg3 at a start time of a second instance of the waiting period, the Msg3 having a timing advance including a sum of the TA1 and the TA2; After expiration of the second instance of the waiting period, the wireless communication device monitors after a delay including a sum of a third timing advance TA3 and a fourth timing advance TA4 to receive Msg4 and a second RRC message in a contention resolution window.

15. The method according to claim 14, wherein: At least one of the following: The TA1 is a propagation delay calculated by the wireless communication device at the start time of the first instance of the waiting period; The TA2 is a propagation delay between the wireless communication device and the satellite calculated when the satellite transmits the Msg2 or MsgB to the wireless communication device; The TA3 is a propagation delay between the wireless communication device and the satellite calculated when the wireless communication device sends the Msg3; The TA4 is a propagation delay between the wireless communication device and the satellite calculated when the wireless communication device receives the Msg4.

16. The method according to claim 15, wherein: In response to the waiting period expiring, if the wireless communication device does not receive the Msg2, Msg4 or MsgB: After a defined offset time, the wireless communication device retransmits the Msg1, Msg3 or MsgA to the satellite at a start time of another instance of the waiting period.

17. The method according to claim 5, 10 or 14, wherein: At least one of the following: The wireless communication device receives the Msg2 or MsgB from the satellite in a RAR window, the window expanding to include a common timing advance of a plurality of wireless communication devices or a maximum round-trip propagation delay between the wireless communication device and the satellite; The wireless communication device monitors to receive the Msg4 within a contention resolution window, the contention resolution window expanding to include the common timing advance or the maximum round-trip propagation delay between the wireless communication device and the satellite.

18. A method comprising: The wireless communication device receives a configuration to be used during a random access procedure, the configuration comprising a wait duration indicating a duration of a next service period to a satellite and a service duration indicating a duration of a service period for the satellite; The waiting duration and the service duration are configured by a wireless communication node.

19. A non-transitory computer-readable medium storing instructions which, when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 1-18.

20. An apparatus comprising: At least one processor, the at least one processor being configured to perform the method according to any one of claims 1-18.

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