CN-116419281-B - Method and apparatus for utilizing priority measurements in TNN for mobility between TN-NTNs

Abstract

The present invention provides a management communication in an NTN environment. The disclosure of the present specification provides a method performed by a User Equipment (UE) for radio communication. The method includes transmitting a random access preamble to an NTN (non-terrestrial network) cell, receiving a random access response from the NTN cell, searching for a TN (terrestrial network) cell with a period T, wherein T is determined based on i) a distance between a location of a UE and a reference location of the TN, ii) a signal power from the TN cell, and iii) a service time of the NTN cell.

Inventors

• Pu Zhenxiong
• Liang Runwu
• HUANG JINYE
• LI SHANGXU
• LIN XIUHUAN
• Chang Zaihe

Assignees

• LG 电子株式会社

Dates

Publication Date

20260512

Application Date

20221020

Priority Date

20220107

Claims (6)

1. 1. A method performed by a user equipment, UE, comprising: Identifying an inter-frequency cell and performing a synchronization signal-reference signal received power SS-RSRP or SS-reference signal received quality SS-RSRQ measurement of the identified inter-frequency cell based on carrier frequency information provided by a serving cell, Wherein the serving cell is a non-terrestrial network NTN cell, an Wherein the inter-frequency cell corresponds to a terrestrial network TN cell; a) Based on the cell selection reception level value being above the cell selection reception level threshold and the cell selection quality value being above the cell selection quality threshold; i) Searching for higher priority inter-frequency layers at least with each period of the value T, comprising: determining a value K as an integer based on i) a distance between the UE and the TN cell and ii) a remaining service time of the NTN cell, Wherein the value T is defined by the following equation: T = (K n) for a second, Where N is the total number of higher priority frequencies broadcast in the system information, and Ii) performing a cell reselection to a cell on a higher priority frequency; b) Based on the cell selection reception level being less than or equal to the cell selection reception level threshold or the cell selection quality level being less than or equal to the cell selection quality level threshold: i) Searching and measuring equal priority inter-frequency layers, and Ii) performing cell reselection to cells on equal priority frequencies based on the ranking of the serving cell and the cells on the equal priority frequencies, Wherein cells on the equal priority frequencies are ranked at least 3dB better than the serving cell with a negative offset in the frequency range-1 FR1, or are ranked 4.5dB better than the serving cell with a negative offset in the frequency range-2 FR2, and Wherein the negative offset is applied to facilitate the cell reselection to the TN cell.
2. 2. The method of claim 1, wherein the value K is greater than 60 based on a distance between the UE and the TN-cell being greater than a first threshold.
3. 3. The method of claim 1, wherein the value K is less than 60 based on a distance between the UE and the TN-cell being less than a first threshold.
4. 4. The method of claim 1, wherein the value K is greater than 60 based on a remaining service time of the NTN cell being greater than a second threshold.
5. 5. The method of claim 1, wherein the value K is less than 60 based on a remaining service time of the NTN cell being less than a second threshold.
6. 6. A user equipment, UE, comprising: At least one of the transceivers of the at least one transceiver, At least one processor operatively connected to the at least one memory, Wherein the at least one memory stores instructions that, based on execution by the at least one processor, cause the UE to perform operations comprising: Identifying an inter-frequency cell and performing a synchronization signal-reference signal received power SS-RSRP or SS-reference signal received quality SS-RSRQ measurement of the identified inter-frequency cell based on carrier frequency information provided by a serving cell, Wherein the serving cell is a non-terrestrial network NTN cell, an Wherein the inter-frequency cell corresponds to a terrestrial network TN cell; a) Based on the cell selection reception level value being above the cell selection reception level threshold and the cell selection quality value being above the cell selection quality threshold: i) Searching for higher priority inter-frequency layers at least with each period of the value T, comprising: determining a value K as an integer based on i) a distance between the UE and the TN cell and ii) a remaining service time of the NTN cell, Wherein the value T is defined by the following equation: T = (K n) for a second, Where N is the total number of higher priority frequencies broadcast in the system information, and Ii) performing a cell reselection to a cell on a higher priority frequency; b) Based on the cell selection reception level being less than or equal to the cell selection reception level threshold or the cell selection quality level being less than or equal to the cell selection quality level threshold: i) Searching and measuring equal priority inter-frequency layers, and Ii) performing cell reselection to cells on equal priority frequencies based on the ranking of the serving cell and the cells on the equal priority frequencies, Wherein cells on the equal priority frequencies are ranked at least 3dB better than the serving cell with a negative offset in the frequency range-1 FR1, or are ranked 4.5dB better than the serving cell with a negative offset in the frequency range-2 FR2, and Wherein the negative offset is applied to facilitate the cell reselection to the TN cell.

Description

Method and apparatus for utilizing priority measurements in TNN for mobility between TN-NTNs Technical Field The present disclosure relates to mobile communications. Background Third generation partnership project (3 GPP) Long Term Evolution (LTE) is a technology for implementing high-speed packet communication. Many schemes have been proposed for LTE targets including those aimed at reducing user and provider costs, improving quality of service, and extending and improving coverage and system capacity. 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of frequency bands, simple structure, open interfaces, and appropriate terminal power consumption as higher level requirements. The International Telecommunications Union (ITU) and 3GPP have begun working to develop requirements and specifications for New Radio (NR) systems. The 3GPP has to identify and develop the technical components required for new RATs that are successfully standardized to meet both the emergency market demands in time and the longer term requirements imposed by the ITU radio communication sector (ITU-R) International Mobile Telecommunications (IMT) -2020 procedure. Furthermore, even in the more distant future, NR should be able to use any spectral band in the range of at least up to 100 GHz available for wireless communication. NR targets a single technology framework that addresses all usage scenarios, requirements, and deployment scenarios, including enhanced mobile broadband (eMBB), large-scale machine type communications (mMTC), ultra-reliable low-latency communications (URLLC), and so on. NR should be inherently forward compatible. NTN communication has a very large cell radius compared to existing mobile communication networks. Due to the large cell radius, a large path loss may occur. Due to the large path loss, lower throughput and lower quality of service compared to terrestrial networks are expected. Therefore, if the existing terrestrial network technology is applied as it is to NTN communication, inefficiency may occur. In NTN communication, a dedicated search period setting and cell reselection setting are required. Disclosure of Invention The UE of the NTN cell sets a discovery period in consideration of a distance from the TN cell and the like. In addition, the margin is adjusted to facilitate cell reselection to the TN cell. According to an embodiment of the present disclosure, the disclosure of the present specification provides a method performed by a User Equipment (UE) for radio communication. The method includes transmitting a random access preamble to an NTN (non-terrestrial network) cell, receiving a random access response from the NTN cell, searching for a TN (terrestrial network) cell with a period T, wherein T is determined based on i) a distance from the TN cell, ii) a signal power from the TN cell, and iii) a service time of the NTN cell. The present disclosure can have various beneficial effects. For example, by adjusting the measurement period, battery consumption of the terminal can be reduced, cell search can be effectively performed, and effective mobility support can be expected. For example, by making it easier for the UE to serve in a TN cell, better communication quality can be provided to the user. The beneficial effects obtained by the specific examples of the present specification are not limited to the effects listed above. For example, there may be various technical effects that one of ordinary skill in the related art can understand or derive from the present specification. Thus, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of the present disclosure. Drawings Fig. 1 shows an example of a communication system to which embodiments of the present disclosure are applied. Fig. 2 shows an example of a wireless device to which embodiments of the present disclosure are applied. Fig. 3 shows an example of a wireless device to which embodiments of the present disclosure are applied. Fig. 4 shows an example of a UE to which embodiments of the present disclosure are applied. Fig. 5 is an example of a wireless communication system. Fig. 6 illustrates a structure of a radio frame used in NR. Fig. 7 shows an example of subframe types in NR. Fig. 8 shows an example of performing measurements in the case of E-UTRAN and NR (EN) DC. Fig. 9 shows an example of performing measurement in the case of NR carrier aggregation. Fig. 10 shows a non-terrestrial network typical scenario based on transparent payloads. Fig. 11 shows a typical scenario of a non-terrestrial network based on regenerated payloads. Fig. 12 shows a state of a UE related to measurement according to an embodiment of the present specification. Fig. 13 shows a procedure of a UE according to the first disclosure of the present specification. Fig. 14 shows a procedure of a