Method for updating a tracking area and terminal device
By actively determining and indicating the current tracking area through the terminal device, the problem of frequent TAU triggering in non-terrestrial networks is solved, power consumption is reduced, the ping-pong effect is decreased, and the accuracy of network management is improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WISTRON CORP
- Filing Date
- 2025-01-08
- Publication Date
- 2026-06-23
AI Technical Summary
In non-terrestrial networks, terminal devices frequently trigger Tracking Area Updates (TAUs) due to the high-speed movement of satellites and overlapping coverage areas, increasing the core network load and consuming battery power, while also exhibiting a ping-pong effect.
The terminal device obtains its geographical location, determines its own tracking area, and actively sends a request to the network device to indicate the current tracking area and control the timing of the TAU program triggering.
It reduces the power consumption of terminal devices and mitigates the ping-pong effect, thereby improving the accuracy and efficiency of network management.
Smart Images
Figure CN122269221A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a communication technology, and more particularly to a method and terminal device for updating a tracking area. Background Technology
[0002] 3GPP has developed several telecommunications standards, among which Registration Request and Tracking Area Update (TAU) request information play a key role in network registration and connection maintenance.
[0003] Please refer to Figure 1 This is a schematic diagram of the Non-Access Layer (NAS) registration mechanism in a fifth-generation communication system. Figure 1 When a User Equipment (UE) registers with the network for the first time, it sends a Registration Request to the Access and Mobility Management Function (AMF) entity. This Registration Request includes the UE's identity information (such as International Mobile Device Identifier (IMEI) or International Mobile Subscriber Identity (IMSI)) and network capabilities (such as supported frequency bands and services) to ensure that the UE can be correctly identified and authorized by the network.
[0004] The registration acceptance message from the network indicates that the registration request information has been successfully received by the network, and it can also indicate the Tracking Area Identifier (TAI) list to indicate the tracking area corresponding to the UE.
[0005] Please refer to Figure 2 This is a diagram illustrating the TAI list. Figure 2 In a network identification system, the TAI list may include a Public Land Mobile Network Identifier (PLMN ID) and a Tracking Area Code (TAC). The PLMN ID identifies the network operator and typically consists of a 12-bit Mobile Country Code (MCC) and an 8- or 12-bit Mobile Network Code (MNC). The TAC (16 bits long) identifies a specific tracking area within the network.
[0006] When a UE moves to a new tracking area and the Tracking Area Acceptance (TAC) for that area is not in the Tracking Area Inquiry (TAI) list, the UE will initiate a Tracking Area Update (TAU) request to notify the network that its current location has changed. The network will then respond with a TAU acceptance message and update the TAI list to track and manage the UE's location.
[0007] Please refer to Figure 3 This is a schematic diagram of TAU. Figure 3 In this scenario, assume the UE's TAI list includes TAC-1 and TAC-2. In this case, if the UE moves from geographic region 311 corresponding to TAC-1 to geographic region 312 corresponding to TAC-2, a TAU will not be triggered. However, if the UE moves to geographic region 313 corresponding to TAC-3, a TAU will be triggered because TAC-3 is not in the TAI list.
[0008] However, applying the existing TAU program to non-terrestrial networks (NTNs) may present the following challenges.
[0009] (1) Frequent TAU triggering: NTN satellites operate in Low Earth Orbit (LEO) at a speed of approximately 27,000 km / h. When switching between different satellites, the UE may frequently trigger TAU, leading to increased core network load and increased device battery consumption.
[0010] (2) Ping-Pong Effect: NTN satellites operate at altitudes between approximately 500 km and 1200 km. For example, a satellite at an altitude of 500 km has a maximum coverage diameter of approximately 5,064 km. Therefore, to achieve uninterrupted service, NTN must consist of multiple satellites. However, in the boundary areas where satellite coverage overlaps, the system may frequently switch between multiple satellites, causing a ping-pong effect. Summary of the Invention
[0011] In view of this, the present invention provides a method and terminal device for updating the tracking area, which can be used to solve the above-mentioned technical problems.
[0012] This invention provides a method for updating a tracking area, comprising: obtaining the geographical location of a terminal device, wherein the terminal device uses non-terrestrial network communication functions; determining a first tracking area where the terminal device is located based on the geographical location; and in response to the determination that a tracking area update procedure needs to be performed, sending request information to a network device, wherein the request information indicates the first tracking area.
[0013] This invention provides a terminal device, including a transceiver and a processor. The processor is coupled to the transceiver and configured to perform: obtaining the geographical location of the terminal device, wherein the terminal device uses non-terrestrial network communication functions; determining a first tracking area where the terminal device is located based on the geographical location; and, in response to determining that a tracking area update procedure needs to be executed, controlling the transceiver to send request information to a network device, wherein the request information indicates the first tracking area. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the Non-Access Layer (NAS) registration mechanism of a fifth-generation communication system.
[0015] Figure 2 This is a diagram of the TAI list.
[0016] Figure 3 This is a schematic diagram of TAU.
[0017] Figure 4 This is a schematic diagram of a terminal device according to an embodiment of the present invention.
[0018] Figure 5 This is a flowchart illustrating a method for updating the tracking region according to an embodiment of the present invention.
[0019] Figure 6 This is a flowchart illustrating a method for updating the tracking region according to a third embodiment of the present invention.
[0020] Figure 7 This is an application scenario diagram illustrated according to an embodiment of the present invention.
[0021] Figure 8 This is an application scenario diagram illustrated according to an embodiment of the present invention.
[0022] The reference numerals in the attached figures are explained as follows:
[0023] 311~313: Geographical regions
[0024] 400: Terminal device
[0025] 402: Transceiver
[0026] 404: Processor error
[0027] S510, S520, S530, S610, S620, S630, S640, S650, S660: Steps
[0028] M11, M12: Request information
[0029] 710: Overlapping area
[0030] 801, 802: Tracking Area
[0031] 821, 822: Network devices Detailed Implementation
[0032] Please refer to Figure 4 This is a schematic diagram of a terminal device according to an embodiment of the present invention. In different embodiments, the terminal device 400 can be used to implement various communication devices such as a UE.
[0033] exist Figure 4 In this embodiment, terminal device 400 includes a transceiver 402 and a processor 404. Transceiver 402 is configured to transmit and receive signals from other devices within its coverage area. Transceiver 402 is capable of performing analog-to-digital signal conversion (ADC), digital-to-analog signal conversion (DAC), modulation, demodulation, signal amplification, low-pass filtering, and band-pass filtering. For example, transceiver 402 is configured to provide processor 404 with information about received signals, modulate data received from processor 404 into a modulated signal, and transmit the modulated signal to other devices.
[0034] In some embodiments, the terminal device 400 may further include other elements, such as an antenna module for implementing the aforementioned functions of the transceiver 402 and the processor 404.
[0035] Processor 404 may be coupled to transceiver 402. Processor 404 may be, for example, a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), any other type of integrated circuit (IC), a state machine, etc.
[0036] In embodiments of the present invention, the terminal device 400 is, for example, a communication device using NTN communication functionality.
[0037] In some embodiments, the terminal device 400 is, for example, a device that can communicate with a network device, typically a user-held mobile device such as a smartphone, tablet, Internet of Things (IoT) device, satellite phone, or even a drone. These devices are capable of sending and receiving data in a wireless network to enable various applications and services.
[0038] The terminal device 400 with NTN communication capabilities can communicate with non-terrestrial infrastructure, rather than relying solely on traditional terrestrial mobile networks (such as 4G / 5G base stations). This capability allows the device to communicate with satellites (LEO, MEO, or GEO) and high-altitude platform systems (HAPS, such as high-altitude balloons or drones).
[0039] To achieve NTN communication functionality, the terminal device 400 requires specific hardware and software support. For example, it needs a dedicated antenna that supports satellite frequency bands (such as Ka, Ku, and S bands), while high-efficiency modulation and coding techniques can handle high latency and signal attenuation. Furthermore, the terminal device 400 may be equipped with positioning circuitry to achieve precise positioning capabilities to track the location of satellites or the NTN platform.
[0040] In different embodiments, the network devices communicating with terminal device 400 include various types of satellites and High Altitude Platform Systems (HAPS). Satellites are mainly classified into Low Earth Orbit (LEO) satellites, Medium Earth Orbit (MEO) satellites, and Geostationary Orbit (GEO) satellites. HAPS include high-altitude balloons and unmanned aerial vehicles (UAVs) (such as solar-powered UAVs), but are not limited to these.
[0041] In one embodiment, terminal device 400 may use NTN communication functionality, for example, by enabling an NTN communication application. For instance, terminal device 400 may be a smartphone with the NTN communication application installed. When a user of terminal device 400 wishes to use the NTN communication function, the NTN communication application can be enabled accordingly, but this is not a limitation.
[0042] In an embodiment of the present invention, the transmission / reception of the terminal device 400 can be performed by the transceiver 404 controlled by the processor 402.
[0043] In an embodiment of the present invention, the processor 404 may access relevant modules and program code to implement the method for updating the tracking region proposed in the present invention, the details of which are described below.
[0044] Please refer to Figure 5 This is a flowchart illustrating a method for updating the tracking region according to an embodiment of the present invention. The method of this embodiment can be derived from... Figure 4 The terminal device 400 executes the following, which is paired with Figure 4 Component description shown Figure 5 Details of each step.
[0045] In step S510, the processor 404 obtains the geographical location (hereinafter referred to as LO) of the terminal device 400.
[0046] In one embodiment, the processor 404 may obtain the current location of the terminal device 400 as the geographic location LO considered in step S510, for example, through a Global Positioning System (GPS) module or other similar positioning circuitry, but is not limited thereto.
[0047] In step S520, the processor 404 determines the first tracking area where the terminal device 400 is located based on the geographic location (LO).
[0048] In one embodiment, the NTN communication application may record multiple preset tracking areas.
[0049] In some embodiments, the plurality of preset tracking regions are, for example, multiple geographical areas distributed within the coverage area of the NTN service used by the terminal device 400, and each preset tracking region is configured with a corresponding TAC.
[0050] In one embodiment, the processor 404 can determine whether the geographic location LO is located within any of the plurality of preset tracking areas. In response to determining that the geographic location LO is located within a first preset area of the plurality of preset tracking areas, the processor 404 can determine that the first preset area is the first tracking area considered in step S520.
[0051] In an embodiment of the present invention, the processor 404 may determine whether the TAU program needs to be executed.
[0052] In the first embodiment, the processor 404 can determine whether the TAU program needs to be executed by determining whether the terminal device 400 is in the registration stage of the NTN communication function.
[0053] For example, if a user has just activated an NTN communication application, the terminal device 400 may not yet be registered with the corresponding network device. In this case, the processor 404 can determine that the terminal device 400 is in the registration phase of the NTN communication function, and vice versa.
[0054] For example, in some embodiments, as long as the processor 404 has not informed the corresponding network device of the tracking area where the terminal device 400 is located, the processor 404 can determine that the terminal device 400 is in the registration stage of the NTN communication function, but it is not limited to this.
[0055] In the first embodiment, in response to the determination that the terminal device 400 is in the registration stage of the NTN communication function, the processor 404 can determine that the TAU program needs to be executed.
[0056] In the second embodiment, the processor 404 can determine whether the TAU program needs to be executed by determining whether the first tracking area is the same as the tracking area previously occupied by the terminal device 400 (hereinafter referred to as the second tracking area).
[0057] In the second embodiment, the second tracking area is, for example, the tracking area where the terminal device 400 was located when it last informed the network device. That is, the network device currently knows that the terminal device 400 is located in the second tracking area.
[0058] In the second embodiment, in response to the determination that the first tracking area is different from the second tracking area previously in which the terminal device 400 was located, the processor 404 may determine that the TAU program needs to be executed.
[0059] That is, when the processor 404 determines that the first tracking area where the terminal device 400 is currently located is different from the second tracking area previously informed to the network device, the processor 404 may determine that the TAU program needs to be executed, but it may not be limited to this.
[0060] On the other hand, in response to the determination that the first tracking area is the same as the second tracking area previously located by the terminal device 400, the processor 404 can determine that the TAU program does not need to be executed.
[0061] In the third embodiment, if the processor 404 determines in the first embodiment that the terminal device 400 is not in the registration phase of the NTN communication function, this means that the processor 404 may have previously informed the network device of its tracking area. In this case, the processor 404 may continue to execute the means of the second embodiment, but is not limited thereto.
[0062] In step S530, in response to the determination that the TAU procedure needs to be executed, the processor 404 controls the transceiver 402 to send a request message (hereinafter referred to as M1) to the network device, wherein the request message M1 indicates the first tracking area.
[0063] In one embodiment, the request information M1 may indicate the TAC of the first tracking area, and it will be assumed below that the TAC of the first tracking area is "TAC 1", but it is not limited to this.
[0064] In a first embodiment, the processor 404 can control the transceiver 402 to send a registration request corresponding to the NTN communication function as request information M1 to the network device. In one embodiment, the registration request may, for example, have the content shown in Table 1 below.
[0065]
[0066]
[0067] Table 1
[0068] As shown in Table 1, compared to existing registration requests, the registration request proposed in this embodiment of the invention also includes a TAI list. In other words, unlike the prior art where the TAI list is provided by the network, this embodiment of the invention allows the terminal device 400 to provide the TAI list to the network device through a registration request, but it is not limited to this.
[0069] In the second embodiment, the processor 404 can control the transceiver 402 to send the TAU request information as request information M1 to the network device. In one embodiment, the TAU request information may, for example, have the content shown in Table 2 below.
[0070]
[0071]
[0072] Table 2
[0073] As shown in Table 1, compared to existing TAU request information, the TAU request information proposed in this embodiment of the invention also includes a TAI list. In other words, unlike the prior art where the TAI list is provided by the network, this embodiment of the invention allows the terminal device 400 to provide the TAI list to the network device through the TAU request information, but it is not limited to this.
[0074] In one embodiment, after the network device receives the request information M1, it can send back response information to the terminal device 400 accordingly, wherein the response information can indicate that the TAU program of the terminal device 400 has been completed.
[0075] In the first embodiment where the request information M1 is a registration request, the response information is, for example, an acceptance registration information that does not indicate any tracking area.
[0076] In the second embodiment where the request information M1 is a TAU request information, the response information is, for example, an accepted TAU information that does not indicate any tracking area.
[0077] As can be seen from the above, unlike the existing method where the network device provides the updated TAI list to the UE based on the TAU request information from the UE, the technical solution of this embodiment of the invention allows the terminal device 400 using NTN communication function to inform the network device of the first tracking area where the terminal device 400 is currently located through request information M1 (e.g., registration request and / or TAU request information) when it determines that a TAU procedure needs to be initiated.
[0078] This allows the terminal device 400 to initiate the TAU procedure at its own discretion. In this case, when the terminal device 400 is in a fixed position or has not moved to a new tracking area, it will not trigger a TAU due to changes in satellite coverage, which helps reduce the power consumption of the terminal device 400.
[0079] In addition, since the terminal device 400 can accurately obtain the geographical location (LO) (e.g., the GPS location of the terminal device 400), the processor 404 can accurately determine the tracking area, thereby reducing the ping-pong effect problem.
[0080] Please refer to Figure 6 This is a flowchart illustrating a method for updating the tracking region according to a third embodiment of the present invention. The method of this embodiment can be derived from... Figure 4 The terminal device 400 executes the following, which is paired with Figure 4 Component description shown Figure 6 Details of each step.
[0081] In step S610, the processor 404 obtains the geographical location (LO) of the terminal device 400. In step S620, the processor 404 determines the first tracking area where the terminal device 400 is located based on the geographical location (LO). Details of steps S610 and S620 can be found in the descriptions of steps S510 and S520, and will not be repeated here.
[0082] In step S630, the processor 404 can determine whether the terminal device 400 is in the registration stage of NTN communication function.
[0083] If so, the processor 404 may continue to execute step S640 to send the registration request corresponding to the NTN communication function as request information M1 to the network device. Afterwards, the processor 404 may return to step S610 to continuously monitor whether the geographical location of the terminal device 400 has changed to a corresponding tracking area.
[0084] On the other hand, if the processor 404 determines in step S630 that the terminal device 400 is not in the registration stage of the NTN communication function, this means that the processor 404 has previously informed the network device of the tracking area of the terminal device 400 (such as the previously mentioned second tracking area). In this case, the processor 404 can continue to execute step S650 to determine whether the first tracking area is the same as the second tracking area where the terminal device 400 was previously located.
[0085] If so, this means that the TAU procedure does not need to be executed, and the processor 404 can return to step S610 to continuously monitor whether the geographical location of the terminal device 400 has changed to a corresponding other tracking area.
[0086] On the other hand, if the processor 404 determines in step S650 that the first tracking area is different from the second tracking area where the terminal device 400 was previously located, this means that the terminal device 400 has moved to a new tracking area. In this case, the processor 404 can execute step S660 to send the TAU request information as request information M1 to the network device. Afterwards, the processor 404 can return to step S610 to continuously monitor whether the geographical location of the terminal device 400 has changed to a corresponding other tracking area, but it is not limited to this.
[0087] Please refer to Figure 7 This is an application scenario diagram illustrated according to an embodiment of the present invention.
[0088] exist Figure 7 In this scenario, scenario 1 is, for example, the existing TAU mechanism. In scenario 1, since TAC 1 and TAC 2 are based on the signal coverage range of different satellites, there may be an overlap area 710 of several kilometers between TAC 1 and TAC 2. When the terminal device 400 is located in the overlap area 710, the previously mentioned ping-pong effect may occur.
[0089] Additionally, scenario 2 is, for example, the mechanism proposed in an embodiment of the present invention. In scenario 2, since TAC 1 and TAC 2 are distinguished by geographical location / region, there is less overlap between TAC 1 and TAC 2, thereby avoiding the previously mentioned ping-pong effect in the terminal device 400.
[0090] Please refer to Figure 8 This is an application scenario diagram illustrated according to an embodiment of the present invention. In this embodiment, when the terminal device 400 enables the NTN communication function while located in the tracking area 801, the terminal device 400 can determine that it is currently located in the tracking area 801 after obtaining its current geographical location. Then, the terminal device 400 can send a registration request corresponding to the NTN communication function as request information M11 to the network device 821 (e.g., a satellite), wherein the request information M11 may, for example, indicate the TAC of the tracking area 801 (e.g., "TAC 1").
[0091] In this case, the request information M11 may have the format of Table 1, and the TAI list therein may include MCC, MNC and TAC 1, but is not limited to this.
[0092] Accordingly, after receiving the request information M11, the network device 821 may send back a response message indicating that the TAU procedure of the terminal device 400 has been completed (e.g., an acceptance registration message that does not indicate any tracking area).
[0093] Furthermore, after the terminal device 400 moves to the tracking area 802, it can determine that it is currently located in the tracking area 802 after obtaining its current geographical location. In this case, since the terminal device 400 is no longer in the registration phase of the NTN communication function, the terminal device 400 can send TAU request information as request information M12 to the network device 822 when it determines that the current tracking area 802 is different from the previously located tracking area 801. The request information M12 may, for example, indicate the TAC of the tracking area 802 (e.g., "TAC 2").
[0094] In this case, the request information M12 may have the format of Table 2, and the TAI list therein may include MCC, MNC and TAC 2, but is not limited to this.
[0095] Accordingly, after receiving the request information M12, the network device 821 may send back a response information indicating that the TAU procedure of the terminal device 400 has been completed (for example, an accepted TAU information that does not indicate any tracking area).
[0096] In summary, the method proposed in this embodiment of the invention allows a terminal device using NTN communication function to inform the network device of its current tracking area through request information (e.g., registration request and / or TAU request information) when it determines that a TAU procedure needs to be initiated.
[0097] This allows the terminal device to initiate the TAU procedure at its own pace, which helps reduce the terminal device's power consumption and mitigate the ping-pong effect.
[0098] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes and modifications without departing from the concept and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.
Claims
1. A method for updating a tracking region, comprising: The geographical location of the terminal device is obtained by the terminal device, wherein the terminal device uses non-terrestrial network communication functions; The terminal device determines the first tracking area where it is located based on the geographical location; as well as In response to the determination that a tracking area update procedure needs to be performed, the terminal device sends a request message to the network device, wherein the request message indicates the first tracking area.
2. The method of claim 1, further comprising: Determine whether the terminal device is in the registration phase of the non-terrestrial network communication function; In response to the determination that the terminal device is in the registration phase of the non-terrestrial network communication function, it is determined that the tracking area update procedure needs to be executed, and the terminal device sends the registration request corresponding to the non-terrestrial network communication function as the request information to the network device.
3. The method of claim 1, further comprising: In response to the determination that the first tracking area is different from the second tracking area previously in which the terminal device was located, it is determined that the tracking area update procedure needs to be executed, and the terminal device sends the tracking area update request information as the request information to the network device.
4. The method of claim 1, further comprising: The terminal device receives a response message corresponding to the request message, wherein the response message indicates that the tracking area update procedure of the terminal device has been completed.
5. The method of claim 4, wherein the request information is a registration request corresponding to the non-terrestrial network communication function, and the response information is an acceptance registration information that does not indicate any tracking area.
6. The method of claim 4, wherein the request information is a tracking area update request information, and the response information is an acceptance tracking area update information that does not indicate any tracking area.
7. The method of claim 1, further comprising: The terminal device uses the non-terrestrial network communication function by enabling a non-terrestrial network communication application, wherein the non-terrestrial network communication application records multiple preset tracking areas.
8. The method of claim 7, wherein the plurality of preset tracking areas includes a first preset tracking area, and determining the first tracking area where the terminal device is located based on the geographical location includes: The system determines that the geographical location is within the first preset area, and therefore determines that the first preset area is the first tracking area.
9. The method of claim 1, wherein the request information indicates the tracking area code of the first tracking area.
10. A terminal device, comprising: transceiver; as well as A processor, coupled to and configured to execute: The geographical location of the terminal device is obtained, wherein the terminal device uses non-terrestrial network communication functions; The first tracking area where the terminal device is located is determined based on the geographical location; as well as In response to the determination that a tracking area update procedure needs to be performed, the transceiver is controlled to send a request message to the network device, wherein the request message indicates the first tracking area.