Communications in non-terrestrial networks

Abstract

Apparatuses and methods for communication in non-terrestrial networks are provided. A downlink transmission is received (300) from a satellite node. A path loss of an uplink transmission to the satellite node is estimated (302). Based on the path loss, it is determined (304) whether an uplink transmission of the apparatus can reach the satellite node, and if the determination indicates that the transmission will not reach the node, the uplink transmission is suspended (306).

Description

Technical Field

[0001] Exemplary and non-limiting embodiments of the present invention generally relate to wireless communication systems. Embodiments of the present invention particularly relate to apparatus and methods in wireless communication networks. Background Technology

[0002] Wireless communication systems are constantly evolving. In addition to traditional cellular communication, non-terrestrial networks can be used for communication, especially where coverage of terrestrial access nodes is poor. Designing communication systems that utilize both cellular and non-terrestrial networks presents challenges due to the different propagation environments.

[0003] The NR solution supporting non-terrestrial networks (NTN) in 3GPP TR 38.821 V1.1.0 (2019-12) (version 16) discusses communication utilizing non-terrestrial networks. Summary of the Invention

[0004] The following is a simplified overview of the invention to provide a basic understanding of certain aspects of it. This overview is not a comprehensive summary of the invention. It is not intended to identify the principal / key elements of the invention, nor is it intended to define the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that follows.

[0005] According to one aspect of the present invention, the apparatus of claim 1 is provided.

[0006] According to one aspect of the present invention, the method of claim 8 is provided.

[0007] According to one aspect of the invention, a computer program including instructions as claimed in claim 15 is provided.

[0008] One or more examples of the implementation are set forth in more detail in the accompanying drawings and the description below. Other features will be apparent from the specification, the drawings, and the claims. Embodiments and / or examples and features (if any) described herein that are not within the scope of the independent claims are to be construed as examples useful for understanding various embodiments of the invention. Attached Figure Description

[0009] The embodiments of the present invention are described below by way of example only with reference to the accompanying drawings, in which...

[0010] Figure 1 An example of a simplified system architecture for a communication system is shown;

[0011] Figure 2 An example of path loss during 2GHz satellite node transmission is shown;

[0012] Figure 3 This is a flowchart illustrating an embodiment;

[0013] Figure 4 An example of path loss in satellite node transmission is shown;

[0014] Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 This is a flowchart illustrating an embodiment;

[0015] Figure 10 and Figure 11 An example of path loss during 2GHz satellite node transmission is shown; and

[0016] Figure 12 An example of the device is shown. Detailed Implementation

[0017] Figure 1 Devices 100 and 102 are shown. For example, devices 100 and 102 may be user equipment or user terminals. Devices 100 and 102 are configured to be wirelessly connected to node 104 on one or more communication channels. Node 104 is further connected to core network 106. In one example, node 104 may be an access node, such as an (e / g)NodeB serving device in a cell. In one example, node 104 may be a non-3GPP access node. The physical link from a device to the (e / g)NodeB is called an uplink or reverse link, while the physical link from the (e / g)NodeB to the device is called a downlink or forward link. It should be understood that the (e / g)NodeB or its functionality can be implemented using any entity suitable for this purpose, such as a node, host, server, or access point.

[0018] A communication system typically includes one or more (e / g)NodeBs, which may also be configured to communicate with each other via wired or wireless links designed for this purpose. These links can be used for signaling purposes. An (e / g)NodeB is a computing device configured to control the radio resources of the communication system to which it is coupled. A NodeB may also be referred to as a base station, access point, or any other type of interface device, including relay stations capable of operating in a wireless environment. An (e / g)NodeB includes or is coupled to a transceiver. From the transceiver of the (e / g)NodeB, a connection is provided to an antenna element that establishes a bidirectional radio link with the device. The antenna element may include multiple antennas or antenna elements. The (e / g)NodeB is further connected to the core network 106 (CN or Next Generation Core NGC). Depending on the system, the counterpart on the CN side may be a Serving Gateway (S-GW, which routes and forwards user data packets), a Packet Data Network Gateway (P-GW) for providing connectivity from the device (UE) to an external packet data network, or a Mobility Management Entity (MME), etc.

[0019] This device (also known as a subscriber unit, user device, user equipment (UE), user terminal, terminal equipment, etc.) illustrates a type of device on which resources on the air interface are allocated and distributed, and therefore any feature of the device described herein can be implemented by a corresponding device (such as a relay node). An example of such a relay node is a Layer 3 relay (self-backhaul relay) toward a base station.

[0020] The device typically refers to devices such as portable or non-portable computing devices, including wireless mobile communication devices that operate with or without a Universal Subscriber Identity Module (USIM), including but not limited to: mobile stations (mobile phones), smartphones, personal digital assistants (PDAs), cell phones, devices using wireless modems (such as alarm or measuring devices), laptops and / or touchscreen computers, tablets, game consoles, and multimedia devices. It should be understood that the device can also be a virtually exclusive uplink-only device, an example of which is a camera or camcorder that loads images or video clips onto a network. The device can also be a device capable of operating in an Internet of Things (IoT) network, a scenario in which objects have the ability to transmit data over a network without human-to-human or human-to-computer interaction, as used in smart grids and connected vehicles, for example. The device can also leverage the cloud. In some applications, the device may include a user portable device with radio components (such as a watch, headset, or glasses), and computation is performed in the cloud. The device (or in some embodiments, a Layer 3 relay node) is configured to perform one or more of the user equipment functions.

[0021] The various techniques described in this paper can also be applied to cyber-physical systems (CPS) (systems that coordinate and control computational elements of physical entities). CPS can enable the implementation and utilization of a large number of interconnected information and communication technology (ICT) devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects in different locations. Mobile cyber-physical systems (physical systems under discussion in which inherent mobility is present) are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals.

[0022] Furthermore, although the device has been described as a single entity, it can implement different units, processors, and / or memory units (not all of which are in one). Figure 1 (as shown in the image).

[0023] 5G enables the use of multiple-input multiple-output (MIMO) antennas, more base stations or nodes than LTE (the so-called small cell concept), including macro sites that operate in cooperation with smaller base stations and employ various radio technologies, depending on service requirements, use cases, and / or available spectrum. 5G mobile communications support a wide range of use cases and related applications, including video streaming, augmented reality, different methods of data sharing, and various forms of machine-type applications (such as (massive) machine-type communications (mMTC)), including vehicle safety, various sensors, and real-time control. 5G is expected to have multiple radio interfaces, such as sub-6 GHz or above 24 GHz, cmWave, and mmWave, and can also integrate with existing legacy radio access technologies (such as LTE). Integration with LTE can be implemented, at least in the early stages, as a system where macro coverage is provided by LTE and 5G radio interface access comes from small cells via aggregation to LTE. In other words, 5G is planned to support both RAT interoperability (such as LTE-5G) and RI interoperability (radio interface interoperability, such as sub-6 GHz – cmWave, 6 or above 24 GHz – cmWave and mmWave). One of the concepts believed to be used in 5G networks is network slicing, in which multiple independent and dedicated virtual subnets (network instances) can be created within the same infrastructure to run services with different requirements for latency, reliability, throughput, and mobility.

[0024] The current architecture in LTE networks is entirely distributed across radios and entirely centralized in the core network. Low-latency applications and services in 5G require content to be closer to the radio, leading to local bursts and multi-access edge computing (MEC). 5G enables analytics and knowledge generation to occur at the data source. This approach requires leveraging resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for hosting applications and services. It also has the ability to store and process content near cellular subscribers to accelerate response times. Edge computing encompasses a wide range of technologies, such as wireless sensor networks, mobile data acquisition, mobile signature analytics, collaborative distributed peer-to-peer self-organizing networks and processing (which can also be categorized as local cloud / fog computing and grid / mesh computing), dew computing, mobile edge computing, small clouds, distributed data storage and retrieval, autonomous and self-healing networks, remote cloud services, augmented and virtual reality, data caching, the Internet of Things (IoT) (massive connectivity and / or latency critical), and critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications).

[0025] The communication system can also communicate with other networks, such as the public switched telephone network, VoIP networks, the Internet, or private networks, or utilize the services provided by them. The communication network may also be able to support the use of cloud services; for example, at least a portion of the core network operation can be performed as a cloud service (this is in...). Figure 1 (Described by “Cloud” 114). The communication system may also include a central control entity that provides facilities for different operators’ networks to cooperate, for example, in spectrum sharing.

[0026] Edge cloud technology can be introduced into the radio access network (RAN) by leveraging Network Functions Virtualization (NFV) and Software-Defined Networking (SDN). Using edge cloud technology means that access node operations are performed, at least partially, in servers, hosts, or nodes that are operationally coupled to remote radio heads or base stations, including the radio portion. Node operations can also be distributed across multiple servers, nodes, or hosts. The application of the cloud RAN architecture enables real-time RAN functions to be performed at or near remote antenna sites (in the distributed unit DU 108), and non-real-time functions to be performed centrally (in the central unit CU 110).

[0027] It should also be understood that the workload allocation between core network operations and base station operations may differ from, or even not exist at all, in LTE. Some other technological advancements that may be used include big data and all-IP, which could potentially change how networks are built and managed. 5G (or New Radio) networks are designed to support multiple hierarchical structures, where MEC servers can be placed between the core and base stations or NodeBs (gNBs). It should be understood that MEC can also be applied to 4G networks.

[0028] 5G can also leverage satellite communications to enhance or supplement the coverage of 5G services, such as by providing backhaul. Possible use cases include providing service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for vehicle passengers, or ensuring the availability of critical communications and future rail / maritime / aviation communications. Satellite communications can utilize geostationary Earth orbit (GEO) satellite systems or low Earth orbit (LEO) satellite systems, particularly mega-constellations (systems deploying hundreds of (nano) satellites). Each satellite in a mega-constellation can cover several satellite-enabled network entities that create a ground cell. Ground cells can be created via ground relay nodes or by gNBs located on the ground or in satellites.

[0029] It will be apparent to those skilled in the art that the depicted system is merely an example of a portion of a radio access system, and in practice, the system may include multiple (e / g) NodeBs that can access multiple radio cells, and may also include other devices such as physical layer relay nodes or other network elements. At least one (e / g) NodeB may be a home (e / g) NodeB. Furthermore, multiple different types of radio cells and multiple radio cells may be provided within the geographical area of ​​the radio communication system. Radio cells may be macrocells (or umbrella cells), which are large cells typically tens of kilometers in diameter, or smaller cells such as micro, femtocells, or picocells. Figure 1 The (e / g)NodeB can provide any type of these cells. Cellular radio systems can be implemented as multi-layer networks comprising several cells. Typically, in a multi-layer network, one access node provides one or more cells, and therefore multiple (e / g)NodeBs are required to provide this network structure.

[0030] To meet the need for improved deployment and performance of communication systems, the concept of "plug and play" (e / g) NodeBs was introduced. Typically, in addition to home (e / g) NodeBs (H(e / g) nodeBs), networks capable of using "plug and play" (e / g) NodeBs also include home NodeB gateways or HNB-GWs ( Figure 1(Not shown in the image). HNB gateways (HNB-GWs), typically installed within a carrier's network, can aggregate services from a large number of HNBs back to the core network.

[0031] In communications involving connections between terminal devices and satellite nodes, extreme operational link loss is a challenging aspect compared to terrestrial networks where terminal devices communicate with relatively nearby RAN nodes. In NR, it has been proposed that at least some terminal devices can communicate with satellites, which can be low Earth orbit (LEO) or geostationary equatorial orbit (GEO) satellites utilizing the FR1 frequency range. In NR, terminal devices exist at different power levels. For example, this solution is applicable to terminal devices of power level 3.

[0032] Terminal devices are typically battery-powered. Therefore, in many cases, their power consumption is limited. Thus, energy efficiency for terminal devices is a crucial goal in network design. When communicating with satellite nodes, terminal devices may be forced to transmit at high power due to the length of the transmission link and high path loss. In terrestrial networks, long transmission links can usually be avoided by placing RAN nodes at appropriate distances from each other. This is not possible in satellite communications because satellites are at very high altitudes.

[0033] Figure 2 An example of path loss at a 2 GHz transmission frequency is shown, with the x-axis representing the distance (in kilometers) between the terminal device and a satellite node at an altitude of 600 km, and the y-axis representing the path loss (in dB) from the lowest point to an elevation angle of 10°. Figure 2 The examples do not consider satellite node antenna gain and terminal device antenna gain. Curve 200 shows an example of free-space path loss varying with distance. Curve 202 shows an example of path loss when effects occurring along the transmission path are considered. These effects (some of which depend on distance) include atmospheric absorption, scintillation, and precipitation, which, for example, increase path loss. These curves illustrate how LEO generates and maintains a geostationary beam via satellite. The distance difference between the geostationary cell and the terminal device is significant, which, ideally, could result in a path loss difference of 10 dB.

[0034] In communications involving connections between terminal devices and satellite nodes, path loss may be too high for the terminal transmitter. Even with full power transmission, the terminal transmission may still fail to reach the satellite node. In such cases, the terminal wastes power attempting to transmit to the satellite node.

[0035] Figure 3The flowchart illustrates one embodiment. This flowchart shows an example of the operation of the device. In one embodiment, the device may be a terminal device, a user device, part of a terminal device, or any other device capable of performing the following steps.

[0036] In step 300, the device is configured to receive downlink transmissions from a satellite node.

[0037] In step 302, the device is configured to estimate the path loss of uplink transmission to the satellite node.

[0038] In step 304, the device is configured to determine whether its uplink transmission can reach the satellite node based on path loss.

[0039] In step 306, if it is determined that the transmission will not reach the node, the device is configured to suspend uplink transmission. In one embodiment, the device is configured to suspend user plane uplink transmission but allow control plane uplink transmission.

[0040] In one embodiment, the terminal device is configured to assess whether it has sufficient signal strength to reach the satellite node, or whether it should schedule uplink transmissions in a more advantageous manner to conserve battery or power on wasted uplink data. The 2GHz F1 frequency is used as an example below, but the proposed scheme is applicable to all frequency ranges.

[0041] Figure 4 An embodiment is shown. For example... Figure 2 As shown, the x-axis represents the distance (in kilometers) between the terminal device and the satellite node at an altitude of 600 km, and the y-axis represents the path loss (in dB) from the lowest point (90° elevation angle) to the 10° elevation angle. Therefore, this figure illustrates the passage of the satellite node on the ground-based terminal device.

[0042] Assuming the device and satellite node antennas provide the margin shown in shaded area 400, the device will handle all uplink / downlink operations throughout the satellite's passage. This would occur, for example, if path loss follows curve 200.

[0043] Shaded area 402 indicates the region outside the uplink transmission capability of the terminal device. If the link degrades from area 400 to area 402, the terminal device's uplink transmission may not reach the satellite node. For example, assuming the path loss of curve 202, the terminal device may only reach the satellite node at a distance of 880 km. In one embodiment, the terminal device may estimate the path loss and suspend its initial access procedure or its uplink scheduling request until it can safely reach the satellite. This helps the terminal device save power and avoids unnecessary interference caused by the device transmitting signals that are now merely noise at its maximum output power level.

[0044] Here, we can distinguish between two types of communication between the terminal device and the satellite node: the initial access procedure and the connection mode, in which uplink scheduling in the user plane (U plane) is performed. The difference between the initial access procedure and the U plane uplink scheduling can be represented as the difference in output power between control plane transmission and data transmission for different payloads.

[0045] For initial access, the uplink terminal equipment can follow a standard idle mode scheme. Furthermore, it can use signal strength information received from the satellite node to determine the link loss at a given distance from the satellite node. For this link loss, the equipment can schedule an additional idle mode counter in case initial access is required when the satellite node is within the uplink transmission capacity of the control plane (C plane).

[0046] Regarding the connection mode, even if the uplink does not request U-plane uplink services, C-plane uplink signaling still needs to reach the satellite node so that the connection is not declared as failed. Figure 4 The shaded area 400 in the example indicates the maximum operating range of the uplink C-plane. This means that the operating range of the uplink U-plane needs to be considered smaller. Transmissions on the C-plane typically use the lowest coded modulation scheme, which allows transmission without maximum output power backoff. However, because U-plane transmissions use higher coded schemes, more bandwidth, and higher modulation orders, the maximum output power is backed off to meet linearity requirements. This reduces the transmission range on the U-plane.

[0047] Consider a scenario where a terminal device is communicating with an LEO satellite node and attempts to hand over to the next satellite node when the current satellite node moves to an unreachable location. In the event of a failed handover, the terminal device can evaluate the initial access process as needed, and to conserve power and reduce interference, it can suspend its uplink C-plane transmission to the satellite until it has estimated that the uplink transmission can reach the satellite node.

[0048] In one embodiment, the determination of whether the uplink transmission of the device can reach the satellite node is based at least in part on an estimate of the link loss between the terminal device and the satellite node. The link loss estimate can then be based at least in part on some of the following:

[0049] - Antenna gain of the terminal equipment (both transmitting and receiving sides)

[0050] - Uplink power level of the terminal device (e.g., power level 3, 23dBm)

[0051] - The known or predictable distance between the terminal device and the satellite node. For example, this distance can be determined from ephemeris data. This distance does not need to be a high-resolution number.

[0052] - The transmitted downlink power of the satellite node. It can be decoded into an integer (-60dBm...+50dBm) from the synchronization signal block transmitted by the satellite node and combined with the measured received downlink power transmitted by the satellite node, as an estimate of the total coupling loss.

[0053] - Frequency offset between downlink and uplink frequencies.

[0054] In one embodiment, uplink degradation can be detected from a series of low uplink modulation and coding scheme (MCS) scheduling.

[0055] In one embodiment, a low downlink modulation and coding scheme indicates downlink link degradation, so the uplink link is also likely to experience degradation.

[0056] In one embodiment, received uplink fast power control commands can be monitored for adjustment. Continuous commands for maximum transmission power indicate the degraded uplink link budget.

[0057] Upon initial access, the terminal device follows the system procedures for initial access. In the case of NR, this means responding to a broadcast channel containing a Synchronization Signal Block (SSB) transmitted by a satellite node. When the terminal device is already in idle mode, it can utilize knowledge of satellite distance and link quality estimates when the satellite is at low elevation. If the satellite is far away and link loss prevents transmission from reaching the satellite, the terminal device can choose to suspend its transmission or even enter / re-enter idle mode. Once the terminal device has performed initial access and established a connection, it enters normal operation. An example of this process is shown below. Figure 5 As shown.

[0058] In step 500, the terminal device receives downlink transmissions from the satellite node.

[0059] In step 502, the terminal device is configured to estimate the path loss of uplink transmission to the satellite node. In one embodiment, this estimation may be based at least in part on the problems described above.

[0060] In step 504, the terminal device is configured to compare the estimated path loss with a predetermined threshold.

[0061] If the path loss is below a given threshold, the terminal is configured to perform a 506 uplink initial access. If the path loss is not below the given threshold, the terminal is configured to suspend a 508 initial access to the user plane.

[0062] During normal downlink / uplink operation, the terminal device uses regular receive and transmit time slots according to system protocols (such as the NR protocol). When the terminal device receives data from emerging satellites on the horizon, it begins to assess the link quality with the satellites. After obtaining a path loss estimate, it must determine whether uplink operation needs to be paused, and if so, it enters a state where it maintains a user plane pause while waiting for a transmission opportunity that meets a threshold defining the link quality estimate. Ultimately, the device can autonomously schedule the conditions for each passing satellite to enter and exit the user plane pause. An example of this process is shown below. Figure 6 As shown.

[0063] In step 600, the terminal device receives downlink transmissions from the satellite node.

[0064] In step 602, the terminal device is configured to estimate the path loss of uplink transmission to the satellite node. In one embodiment, this estimation may be based at least in part on the problem described above.

[0065] In step 604, the terminal device is configured to assess whether the uplink U plane will be suspended.

[0066] If the U plane will not be suspended, the terminal is configured to perform 606 uplink scheduling to acquire uplink transmission resources. If the U plane will be suspended, the terminal is configured to suspend 608 user plane transmissions.

[0067] In one embodiment, the above process can be further refined by adding margin, timers, or threshold management. Figure 7 , Figure 8 and Figure 9 The flowchart in the document shows an example.

[0068] Figure 7 An example of the entire process is shown, and Figure 8 and Figure 9 Two tests performed during this process are shown.

[0069] from Figure 7 Initially, in step 700, the terminal device receives downlink transmissions from the satellite node.

[0070] In step 702, the terminal device is configured to estimate the path loss of uplink transmission to the satellite node. In one embodiment, this estimation may be based at least in part on the problems described above.

[0071] In step 704, the terminal device is configured to determine whether uplink transmission on the U plane is currently suspended.

[0072] If uplink transmission on the U plane is not currently paused, then in step 706, the so-called IN condition is tested. This is in Figure 8 A more detailed description is provided below.

[0073] If the IN condition is not met, the terminal is configured to perform 708 uplink scheduling to acquire uplink transmission resources.

[0074] If the IN condition is met, the terminal is configured to disable uplink transmission in step 710 and suspend the uplink user plane in step 712.

[0075] If uplink transmission on the U plane is currently suspended, then in step 714, the so-called OUT condition is tested. This is in Figure 9 A more detailed description is provided below.

[0076] If the OUT condition is not met, the terminal is configured to continue suspending the uplink user plane in step 716.

[0077] If the OUT condition is met, the terminal is configured to enable uplink transmission in step 718 and performs uplink scheduling in step 720 to acquire uplink transmission resources.

[0078] In one embodiment, the IN and OUT conditions utilize two path loss thresholds (Threshold1 and Threshold2) and two counter thresholds (ULCountThr1 and ULCountThr2). Additionally, three counters are used: T-Suspend, Counter1, and Counter2.

[0079] IN condition 706 test as follows Figure 8 As shown.

[0080] In step 800, the terminal device is configured to compare the estimated path loss with Threshold1.

[0081] If the path loss is less than Threshold1, then in step 802, counters Counter1 and Counter2 are reset to zero, and the terminal device transmits uplink scheduling request 804 to obtain uplink transmission resources.

[0082] If the path loss is not less than Threshold1, then in step 806, counter 1 is incremented and compared with the threshold ULCountThr1.

[0083] If Counter1 is not greater than the threshold ULCountThr1, the terminal device performs 804 uplink scheduling to obtain uplink transmission resources.

[0084] If Counter1 is greater than the threshold ULCountThr1, the terminal device is configured to disable uplink transmission in step 808, reset counters Counter1 and Counter2 to zero in step 810, and suspend the uplink user plane in step 812.

[0085] OUT condition 714 test as follows Figure 9 As shown.

[0086] In step 900, the terminal device is configured to determine whether the counter T_Suspend has expired. If the counter has expired, the terminal device is configured to enable uplink transmission in step 902, reset counters Counter1 and Counter2 to zero in step 904, and perform uplink scheduling in step 906 to acquire uplink transmission resources.

[0087] If the counter has not expired, in step 908, the terminal device is configured to compare the estimated path loss with Threshold2.

[0088] If the path loss is greater than Threshold2, then in step 910, counters Counter1 and Counter2 are reset to zero, and the terminal device suspends the uplink user plane in step 912.

[0089] If the path loss is not greater than Threshold2, then in step 914, counter 2 is incremented and compared with the threshold ULCountThr2.

[0090] If Counter2 is not greater than the threshold ULCountThr2, the terminal device is configured to suspend the uplink user plane in step 912.

[0091] If Counter2 is greater than the threshold ULCountThr2, the terminal device is configured to enable uplink transmission in step 902, reset counters Counter1 and Counter2 to zero in step 904, and perform uplink scheduling in step 906 to obtain uplink transmission resources.

[0092] Figure 10 Threshold1 and Threshold2 are shown.

[0093] In one embodiment, Threshold1 1000 can be defined as below the maximum possible limit, for example, to produce hysteresis, such as... Figure 10 As shown, alternatively, keep uplink services on the C plane (which is more robust to link loss) enabled and disable only user plane services.

[0094] In one embodiment, Threshold2 1002 may be lower than Threshold1 in order to maintain link loss condition checks where possible so that the device operates under “In condition”.

[0095] In one embodiment, an example of a method for performing calculations to determine the path loss to be used in the evaluation of the link estimate as shown in the flowchart above is illustrated below. It can be noted that other methods may also be used.

[0096] First, the terminal device can determine its own location and the location of the satellite node.

[0097] Then, the distance d to the satellite node is calculated.

[0098] Next, determine the frequency f of system operation.

[0099] The free space loss between the terminal device and the satellite node can be calculated using the following equation:

[0100]

[0101] Where c is the speed of light.

[0102] The uplink transmission power received at the satellite can be calculated using the following equation:

[0103] UL power at the satellite = P MAX +G TX_Devi ce+G RX_SAT -Free space path loss

[0104] Where P MAX It is the maximum transmission output power of the terminal device, G. TX_Device It refers to the antenna gain of the terminal equipment, G. RX_SATis the satellite antenna gain, which can be provided by the system or a fixed estimate.

[0105] In one embodiment, the calculation of the uplink transmission power received at the satellite can be used by the terminal device in the condition check of Pathloss < Threshold1 or Threshold2 to determine what state to select. This condition check can include the sensitivity level information from the network or the device estimate based on the internally calculated gNB sensitivity. When using the internal calculation for gNB sensitivity, the thresholds (Threshold1 and Threshold2) can include the margin and tolerance of the gNB's sensitivity estimate.

[0106] Figure 11 An example of a satellite node passing over a terminal device is shown, where the satellite has an altitude of 600 km. The distance between the terminal device and the satellite node (in kilometers) is on the x-axis, and the path loss at a frequency of 2 GHz (in dB) is on the y-axis. The figure also shows the thresholds Threshold1 and Threshold2.

[0107] When the satellite node appears from the left, the distance between the node and the terminal device is thus large. The terminal device is configured to pause the uplink user plane 1100. In Figure 7 In the flowchart of Figure 7 the OUT condition is applied. As the satellite node gets closer, the terminal device is configured at a certain point to enable uplink transmission and perform uplink scheduling 1102. In Figure 7 the flowchart of

[0108] During the condition process of entering and exiting the paused UL mode, other methods can be applied.

[0109] For example, ephemeris statistics including satellite approach or descent can be utilized. The uplink negative acknowledgment NACK can be used as a threshold check to count a given number of NACKs or ACKs as an indication before entering the in / out condition. Additionally, the transmission power control instruction can be used as a condition similar to the NACK threshold check, where the transmission power control instruction is counted in the boundary state to indicate whether the satellite node is within the reachable range or outside the reachable range.

[0110] The proposed solution has multiple advantages. The power consumption of the terminal device can be reduced when the terminal device does not attempt to transmit to an unreachable satellite node.

[0111] In one embodiment, the terminal device may indicate to the user whether the link quality of the user plane in the uplink has been affected compared to the downlink.

[0112] Figure 12 An embodiment is illustrated. This figure shows a simplified example of a device to which an embodiment of the present invention is applied. In some embodiments, the device may be terminal device 102 or part of a terminal device.

[0113] It should be understood that the device described herein is an example illustrating some embodiments. It will be apparent to those skilled in the art that the device may also include other functions and / or structures, and not all described functions and structures are necessary. Although the device is described as a single entity, different modules and memories may be implemented in one or more physical or logical entities.

[0114] The example device 102 includes a control circuit system 1200 configured to control at least a portion of the operation of the device.

[0115] The device may include a memory 1202 for storing data. Furthermore, the memory may store software 1204 executable by the control circuitry system 1200. The memory may be integrated into the control circuitry system.

[0116] The device may include one or more interface circuitry systems 1206, 1208. The interface circuitry systems are operatively connected to the control circuitry system 1200. Interface circuitry system 1206 may be a set of transceivers configured to communicate with RAN nodes (such as (e / g) NodeBs or satellite nodes in a wireless communication network). The interface circuitry system may be connected to an antenna arrangement (not shown). The device may also include connections to transmitters instead of transceivers. The device may also include a user interface 1208.

[0117] In one embodiment, the software 1204 may include a computer program that includes program code means adapted to cause the control circuitry system 1200 of the device to implement at least some of the embodiments described above.

[0118] The steps and related functions described above and in the accompanying figures do not have an absolute temporal order, and some steps may be performed simultaneously or in a different order than given. Other functions may also be performed between or within steps. Some steps may also be omitted or replaced with corresponding steps.

[0119] The apparatus or controller capable of performing the above steps can be implemented as an electronic digital computer, processing system, or circuit system, which may include working memory (random access memory, RAM), a central processing unit (CPU), and a system clock. The CPU may include a set of registers, an arithmetic logic unit, and a controller. The processing system, controller, or circuit system is controlled by a sequence of program instructions transferred from RAM to the CPU. The controller may contain multiple microinstructions for basic operations. The implementation of the microinstructions may vary depending on the CPU design. The program instructions may be encoded in a programming language, which may be a high-level programming language, such as C or Java, or a low-level programming language, such as machine language or assembler. The electronic digital computer may also have an operating system that provides system services to the computer program written with the program instructions.

[0120] As used in this application, the term "circuit system" means all of the following: (a) hardware circuitry implementations only, such as implementations only in analog and / or digital circuitry systems; and (b) combinations of circuitry and software (and / or firmware), such as (if applicable): (i) combinations of (multiple) processors, or (ii) portions of (multiple) processors / software (including (multiple) digital signal processors), software, and (multiple) memories that work together to cause the device to perform various functions; and (c) circuitry, such as (multiple) microprocessors or portions of (multiple) microprocessors that require software or firmware to perform operations, even if the software or firmware does not actually exist.

[0121] This definition of "circuit system" applies to all uses of the term in this application. As another example, as used in this application, the term "circuit system" will also cover only the implementation of a processor (or processors) or a portion thereof and its accompanying software and / or firmware. For example, if applicable to a particular element, the term "circuit system" will also cover baseband integrated circuits or application processor integrated circuits for mobile phones, or similar integrated circuits in servers, cellular network devices, or other network devices.

[0122] An embodiment provides a computer program embodied on a distribution medium, the computer program including program instructions that, when loaded into an electronic device, are configured to control the device to perform the above embodiment.

[0123] Computer programs can be in the form of source code, object code, or some intermediate form, and can be stored on some kind of carrier, which can be any entity or device capable of carrying the program. Such carriers include recording media, computer memory, read-only memory, and software distribution packages. Depending on the required processing power, computer programs can be executed in a single electronic digital computer or distributed among several computers.

[0124] The device can also be implemented as one or more integrated circuits, such as application-specific integrated circuits (ASICs). Other hardware embodiments are also possible, such as circuits constructed from separate logic components. A mixture of these different implementations is also feasible. When selecting an implementation method, those skilled in the art will consider requirements such as device size and power consumption, necessary processing power, production costs, and production volume.

[0125] In one embodiment, an apparatus includes components for performing the following operations: receiving downlink transmissions from a satellite node; estimating path loss for uplink transmissions to the satellite node; determining, based on the path loss, whether the uplink transmissions of the apparatus can reach the satellite node; and suspending the uplink transmissions if it is determined that the transmissions will not reach the node.

[0126] It will be apparent to those skilled in the art that the concept of this invention can be implemented in various ways as technology advances. The invention and its embodiments are not limited to the examples described above, but can be varied within the scope of the claims.

Claims

1. An apparatus in a communication system, comprising at least one processor; and at least one memory containing computer program code, the at least one memory and the computer program code being configured together with the at least one processor such that the apparatus: Receive (300) downlink transmissions from the satellite node; Its features are, The device is also configured to: estimate (302) the path loss of uplink transmission to the satellite node; Based on the path loss, determine whether the uplink transmission of the device (304) can reach the satellite node; If it is determined that the transmission will not reach the node, then the uplink transmission is paused (306), wherein the pause of the uplink transmission includes pausing the user plane uplink transmission but allowing the control plane uplink transmission.

2. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, together with the at least one processor, such that the apparatus further performs: The uplink transmission of the device can reach the satellite node by comparing the estimated path loss with a given threshold.

3. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, together with the at least one processor, such that the apparatus further performs: Whether the uplink transmission of the device can reach the satellite node is determined based at least in part on one or more of the following: The antenna gain and power level of the device; Distance to the satellite node; The transmission power of the satellite node; Measurement power transmitted by satellite nodes; Frequency offset between downlink and uplink frequencies.

4. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, together with the at least one processor, to cause the apparatus to further perform: When uplink transmission is suspended, a counter is initiated, and When the counter reaches a given threshold, uplink transmission is enabled.

5. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, together with the at least one processor, such that the apparatus further performs the following when uplink transmission is permitted: The path loss is compared with a first threshold, and if the path loss is lower than the first threshold, uplink transmission is allowed to continue. If the path loss is not lower than the first threshold, the first counter is incremented, and if the counter has expired, the uplink transmission is suspended.

6. The apparatus according to any preceding claim, wherein the at least one memory and the computer program code are configured, together with the at least one processor, such that the apparatus further executes, when the uplink is suspended: The path loss is compared with a second threshold, and if the path loss is greater than the second threshold, the uplink transmission is suspended. If the path loss is not greater than the second threshold, then the second counter is incremented, and if the counter has expired, then the uplink transmission is stopped.

7. A method for communication in an apparatus, comprising: Receive (300) downlink transmissions from the satellite node; Its features are: Estimate (302) the path loss of uplink transmission to the satellite node; Based on the path loss, determine whether the uplink transmission of the device (304) can reach the satellite node; If it is determined that the transmission will not reach the node, then the uplink transmission is paused (306), wherein the pause of the uplink transmission includes pausing the user plane uplink transmission but allowing the control plane uplink transmission.

8. The method according to claim 7, further comprising: The uplink transmission of the device can reach the satellite node by comparing the estimated path loss with a given threshold.

9. The method according to claim 7, further comprising: Whether the uplink transmission of the device can reach the satellite node is determined based at least in part on one or more of the following: The antenna gain and power level of the device; Distance to the satellite node; The transmission power of the satellite node; Measurement power transmitted by satellite nodes; Frequency offset between downlink and uplink frequencies.

10. The method of claim 7, further comprising: When uplink transmission is suspended, a counter is initiated, and When the counter reaches a given threshold, uplink transmission is enabled.

11. The method of claim 7, further comprising: The path loss is compared with a first threshold, and if the path loss is lower than the first threshold, uplink transmission is allowed to continue. If the path loss is not lower than the first threshold, the first counter is incremented, and if the counter has expired, the uplink transmission is suspended.

12. The method according to any one of claims 7 to 11, further comprising: The path loss is compared with a second threshold, and if the path loss is greater than the second threshold, the uplink transmission is suspended. If the path loss is not greater than the second threshold, then the second counter is incremented, and if the counter has expired, then the uplink transmission is stopped.

13. A computer-readable medium comprising program instructions, which, when executed by a device, cause the device to perform at least the following: Receive (300) downlink transmissions from the satellite node; Its features are: Estimate (302) the path loss of uplink transmission to the satellite node; Based on the path loss, determine whether the uplink transmission of the device (304) can reach the satellite node; If it is determined that the transmission will not reach the node, then the uplink transmission is paused (306), wherein the pause of the uplink transmission includes pausing the user plane uplink transmission but allowing the control plane uplink transmission.

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