WO2021077600A1

WO2021077600A1 - Terminal paging optimization method based on satellite network

Info

Publication number: WO2021077600A1
Application number: PCT/CN2019/127746
Authority: WO
Inventors: 王健; 吕东
Original assignee: 广州爱浦路网络技术有限公司
Priority date: 2019-10-23
Filing date: 2019-12-24
Publication date: 2021-04-29
Also published as: CN110636609A

Abstract

Provided is a terminal paging optimization method based on a satellite network. The method comprises: a core network accessing a satellite operation control center according to a Cell-ID carried by a user equipment (UE) during position updating, acquiring ground geographic information or space geographic information that corresponds to the Cell-ID, converting the ground geographic information or space geographic information into LAI, and writing same to a GMLC through a user position report; when a network side initiates paging to the UE, the core network requesting the LAI of the UE from the GMLC, and converting the LAI into the ground geographic information or space geographic information; and the core network querying the satellite operation control center for corresponding satellite information and wave beam information according to the ground geographic information or the space geographic information, and issuing a paging message through one or more satellites and corresponding gNBs. According to the method of the present invention, a core network can accurately send a paging message to a target user equipment (UE), thereby achieving the purpose of accurately paging the UE in a satellite network.

Description

Method for paging optimization based on satellite network terminal

Technical field

The present invention relates to the technical field of satellite communication, in particular to a method for paging optimization based on a satellite network terminal.

Background technique

In the LEO satellite network, the user terminal UE can send messages to the satellite, access the core network through the measurement and control station, and exchange information with the data network. The satellite network overcomes the very difficult problem of ground mobile networks in setting up base stations in harsh and sparsely populated places such as mountains, seas, and remote areas, and has great prospects.

The LEO (low-orbit satellite) network communication system consists of multiple low-orbit satellites. The orbit of low-orbit satellites is time-varying. In order to facilitate the management and real-time communication of multi-satellite systems, satellites not only need to be connected to the gateway station of the earth, but also need to be connected through inter-satellite links. The advantages of the LEO low-orbit satellite network communication system are: low orbital height, short transmission delay; low path loss, higher frequency reuse efficiency; existing multiple access, spot beam and other technologies provide technical guarantee for LEO satellite mobile communication .

In a 5G terrestrial mobile communication network, a user terminal UE resides in a serving cell, and the cell access network has a unique identifier. As long as the registered cell where the user terminal UE stays remains unchanged, no location update is required. When the network side initiates paging for the user terminal UE, the AMF will try to page the user terminal UE on all cells in the registration area. However, in the satellite network, the non-synchronous satellite changes in real time relative to the ground, that is, the beam coverage area of the satellite on the ground changes in real time. The core network cannot provide the AMF with the position tracking area information according to the beam information and satellite information when the user terminal UE is registered. , If there is a request to page the user terminal UE, the paging will not be implemented smoothly.

GMLC (Gateway Mobile Location Center) gateway mobile location center is the first node for external location programs to access GSM PLMN (Public Land Mobile Network). It performs registration authorization check and access from HLR (Home Location Register)/ HSS (Home Subscriber Server)/UDM (User Data Module) requests routing information, and a PLMN may have multiple GMLCs. The GMLC stores the current cell ID information of the UE for other legally authorized applications to request and call.

In a 5G terrestrial mobile network, when a user terminal UE registers with the core network, the message will carry the cell-ID of the serving cell to which it belongs, and the AMF saves the Cell-ID as the estimated location information of the user terminal UE. When the user terminal UE switches the serving cell, it will re-register, and the Cell-ID saved in the AMF will be changed accordingly. When the network side pages the user terminal UE, the AMF queries the Cell-ID of the cell where the user terminal UE is located, and then sends the downlink message to the user terminal through the gNB corresponding to the Cell-ID.

In the satellite network, the orbit of the satellite is time-varying. The user terminal UE is registered to the core network through a satellite, and after a period of time, the user terminal UE will relatively leave the ground beam coverage area of the satellite (even if the user terminal UE is not moving). Therefore, the terminal paging method using the 5G terrestrial mobile network cannot successfully page the user terminal UE, and it needs to be optimized.

Summary of the invention

The invention provides a paging optimization method based on a satellite network terminal, which can solve the problem that the user terminal cannot be paged smoothly due to the movement of the satellite in the prior art.

The technical scheme of the present invention is as follows:

The method for paging optimization based on satellite network terminals includes the following steps:

Step S101: The core network visits the satellite operation control center and obtains the ground geographic information or spatial geographic information corresponding to the cell number identifier according to the cell number identifier reported by the user terminal, and converts the ground geographic information or spatial geographic information into a location area Identification, writing the location area identification into the gateway mobile location center through the user location report;

Step S102: When the network side initiates a paging to the target user terminal, the core network requests the mobile location center of the gateway for the location area identifier corresponding to the target user terminal, and parses the location area identifier and converts it back to ground geographic information or spatial geographic information ；

Step S103: The core network visits the satellite operation control center, queries at least one satellite corresponding to the ground geographic information or spatial geographic information in step S102, and sequentially passes the paging message through the at least one satellite and the at least one satellite. The base station corresponding to each satellite is issued to the target user terminal.

Further, the cell number identifier is the identifier of the serving cell where the user terminal is located when the user terminal performs initial registration or the user terminal sends a location update request message to the core network.

Further, the ground geographic information is a satellite ground beam coverage area.

Further, the spatial geographic information is the beam, spatial position and spatial attitude of the satellite.

Further, the method for querying satellites in step S103 is:

By analyzing the location area identifier corresponding to the target user terminal, obtain the ground beam coverage area corresponding to the location area identifier, or obtain the satellite beam, spatial position and spatial attitude corresponding to the location area identifier, and query through the satellite operation control center At least one satellite that covers all or part of the terrestrial beam coverage area, or at least one satellite that covers all or part of the satellite beam, spatial position, and spatial attitude is inquired.

Further, after the paging message is sent through the corresponding satellite and base station in the step S103, if the target user terminal does not respond, the step of expanding the paging range is also included.

Further, the method of expanding the paging range is: taking the ground beam coverage area obtained by analyzing the location area identifier corresponding to the target user terminal as the center, and expanding a neighboring area to the surrounding area according to the set neighboring rules. The following paging range pages the user terminal.

Further, the method for paging the user terminal in the expanded paging range is: querying multiple satellites covering part of the expanded paging range, and sending a paging message through the multiple satellites and the corresponding base station .

The beneficial effects of the present invention are:

Through the method of the present invention, the core network can more accurately send paging messages to the target user terminal UE, optimize the 5G ground mobile network and apply to the satellite network, and achieve the purpose of accurately paging the user terminal in the satellite network.

Description of the drawings

Fig. 1 is a schematic diagram of the steps of a paging optimization method according to the first embodiment of the present invention;

Figure 2 is a diagram of the satellite network architecture;

Figure 3 is a flow chart of writing LAI to GMLC according to the present invention;

Figure 4 is a flow chart of terminal paging according to the present invention;

Fig. 5 is a flow chart of the paging of the terminal after the paging range is expanded according to the present invention.

Detailed ways

The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

The following describes the implementation of the present disclosure through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that, in the case of no conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure.

In addition, in order to avoid ambiguity of related details of the present disclosure, well-known elements will not be described in detail.

Example one

Figure 2 shows the network architecture of the satellite communication system, including a satellite operation and control center, multiple low-orbit satellites, satellite monitoring and control stations for monitoring and controlling multiple low-orbit satellites, and satellite monitoring and control stations, gateway mobile location centers, and satellite operations. The 5G terrestrial core network that the control center interacts with, the satellite user station that connects the base station and multiple low-orbit satellites, the multiple user terminals that interact with the base station,

The method of the present invention is: the core network visits the satellite operation control center and obtains the ground geographic information or spatial geographic information corresponding to the Cell-ID according to the cell ID carried in the location update (Location Update) of the user terminal UE. , Converted to Location Area Identity (LAI), and written into the Gateway Mobile Location Center (GMLC) through the Subscriber Location Report (Subscriber Location Report); when the network side initiates a paging to the user terminal UE, the core The network requests the LAI of the user terminal UE from the GMLC, and converts it into terrestrial geographic information or spatial geographic information; the core network queries the satellite operation control center for the corresponding satellite information and beam information according to the terrestrial geographic information or spatial geographic information. Or multiple satellites and corresponding gNBs issue paging messages.

The specific steps of the method of the present invention include:

Step S101: The core network accesses the satellite operation control center according to the Cell-ID carried during the location update of the user terminal UE and obtains the ground geographic information or spatial geographic information corresponding to the Cell-ID, and converts the terrestrial geographic information or spatial geographic information into LAI ，Write into the gateway mobile location center GMLC through the user location report;

When the user terminal UE performs initial registration or the serving cell where the user terminal UE is located is changed, the user terminal UE sends a location update request message to the core network via satellite; the request message carries the serving cell where the user terminal UE is located at that moment (Satellite) identification Cell-ID; the core network network element authenticates and authenticates the user terminal UE. After the authentication and authentication succeeds, the core network updates the current location area identification (ie LAI) of the user terminal UE, and then sends it to the user terminal The UE returns a location update success response.

The specific process of writing into LAI is shown in Figure 3. In the first operation 1 in Fig. 3, the core network obtains the Cell-ID passed when the user terminal UE location is updated; in the second operation 2 in Fig. 3, the core network accesses the Satellite Control Center (SCC); In the third operation 3 of Fig. 3, the core network obtains from the SCC the ground beam coverage area (ground geographic information) corresponding to the satellite corresponding to the Cell-ID at that moment, or the satellite beam corresponding to the satellite at that moment , Spatial position and spatial posture (spatial geographic information); in the fourth operation 4 in Figure 3, the core network converts terrestrial geographic information or spatial geographic information into LAI; in the fifth operation 5 in Figure 3, the user location report Write to GMLC.

The space attitude of the satellite refers to the state of the space pointing in the orbit of the satellite orbit.

Step S102: When the network side initiates a paging to the target user terminal UE, the core network requests the GMLC for the LAI of the target user terminal UE, analyzes the LAI of the target user terminal UE, and converts it into terrestrial geographic information or spatial geographic information.

Step S103: The core network visits the satellite operation control center, queries one or more satellites corresponding to the ground geographic information or spatial geographic information, and passes the downlink paging message through the one or more satellites and the corresponding one or more satellites. The base station gNB delivers to the target user terminal.

The method for querying the corresponding one or more satellites is: the core network queries the satellite operation control center for one or more satellites that cover all or part of the coverage area of the ground beam obtained by the LAI of the user terminal, or to the satellite The operation control center queries one or more satellites that include all or part of the beam information obtained by analyzing the LAI of the user terminal and the spatial position of the satellites, and sends the search through the queried one or more satellites and the corresponding gNB. Call the news.

Figure 4 is a flow chart from initiating a paging to delivering the paging to the target user terminal. In the first operation 1 in FIG. 4, the core network requests the GMLC for the LAI of the target user terminal UE; in the second operation 2 in FIG. 4, the GMLC returns the LAI of the target user terminal UE to the core network; in the third operation in FIG. At operation 3, the core network parses the LAI of the target user terminal UE and converts it into terrestrial geographic information or spatial geographic information; at the fourth operation 4 of FIG. 4, the core network visits the satellite operation control center SCC to query the ground One or more satellites corresponding to geographic information or spatial geographic information; at the fifth operation 5 in Fig. 4, the satellite operation control center returns the queried information of one or more satellites; at the sixth operation 6 in Fig. 4 , The core network sends a paging message to the target user terminal through the queried satellite or satellites.

In the first embodiment of the present invention, first, paging is performed in the location area reported during the last location update of the target user terminal UE. Because the satellite corresponds to a large terrestrial geographic area, the probability of the user terminal UE leaving the area is small, and the probability of successfully paging the user terminal UE is high.

Example two

On the basis of the first embodiment, if the paging target user terminal does not respond, the step of expanding the paging range is also included.

With reference to the PLMN terrestrial mobile network mechanism, if the user terminal UE does not respond to the network-side paging initiated by a single satellite, the paging range will be expanded according to the set neighboring cell rules to try to find the UE further. After the paging range is expanded, according to the method of Example 1, multiple corresponding satellites are inquired, and the downlink paging message is sent through multiple satellites and the corresponding gNB. The neighbor cell rule refers to the deployment plan of the serving cell. For example, how many kilometers are the distance between two adjacent cells, how large is the coverage area of each cell, and so on.

The specific method for expanding the paging range is: taking the ground beam coverage area obtained by analyzing the LAI as the center, and expanding a neighborhood radius to the surrounding area according to the set neighborhood rule.

Figure 5 is a flow chart of terminal paging with expanded paging range. At the first operation 1 in Fig. 5, the core network queries the satellite operation control center for one or more satellites that cover all or part of the ground beam coverage area obtained by analyzing the LAI of the user terminal, or the satellite operation control center The query includes a part of one or more satellites that analyze the beam information obtained by the LAI of the user terminal and the satellite's spatial position, and send a paging message through the queried one or more satellites and the corresponding gNB; In the second operation 2 of 5, when there is no response to the first paging, the core network expands the paging range according to the ground beam coverage area obtained by analyzing the LAI of the user terminal; in the third operation 3a, 3b, At 3c, the core network sends a paging message through the plurality of satellites and the corresponding gNB according to the multiple satellites that query the satellite operation control center for the expanded paging range.

The above is only to illustrate the embodiments of the present invention and not to limit the present invention. For those skilled in the art, all modifications, equivalent substitutions, and improvements made without creative work are within the spirit and principle of the present invention. Etc., should be included in the protection scope of the present invention.

Claims

The method for paging optimization based on satellite network terminals is characterized in that it includes the following steps:

Step S101: The core network visits the satellite operation control center and obtains the ground geographic information or spatial geographic information corresponding to the cell number identifier according to the cell number identifier reported by the user terminal, and converts the ground geographic information or spatial geographic information into a location area Identification, writing the location area identification into the gateway mobile location center through the user location report;

Step S102: When the network side initiates a paging to the target user terminal, the core network requests the mobile location center of the gateway for the location area identifier corresponding to the target user terminal, and parses the location area identifier and converts it back to ground geographic information or spatial geographic information ；

Step S103: The core network visits the satellite operation control center, queries at least one satellite corresponding to the ground geographic information or spatial geographic information in step S102, and sequentially passes the paging message through the at least one satellite and the at least one satellite. The base station corresponding to each satellite is issued.
The method for paging optimization based on satellite network terminals according to claim 1, characterized in that: the cell number identifier is that when the user terminal initiates registration or the user terminal sends a location update request message, it reports the user to the core network The identity of the serving cell where the terminal is located.
The method for paging optimization based on a satellite network terminal according to claim 1, wherein the ground geographic information is a satellite ground beam coverage area.
The method for paging optimization based on a satellite network terminal according to claim 1, wherein the spatial geographic information is the beam, spatial position and spatial attitude of the satellite.
The method for paging optimization based on a satellite network terminal according to claim 1, wherein the method for querying satellites in step S103 is:

By analyzing the location area identifier corresponding to the target user terminal, obtain the ground beam coverage area corresponding to the location area identifier, or obtain the satellite beam, spatial position and spatial attitude corresponding to the location area identifier, and query through the satellite operation control center At least one satellite that covers all or part of the terrestrial beam coverage area, or at least one satellite that covers all or part of the satellite beam, spatial position, and spatial attitude is inquired.
The method for paging optimization based on a satellite network terminal according to claim 1, characterized in that: after the paging message is sent through the corresponding satellite and base station in the step S103, if the target user terminal does not respond, It also includes steps to expand the paging range.
The method for paging optimization based on a satellite network terminal according to claim 6, wherein the method of expanding the paging range is: centering on the ground beam coverage area obtained by analyzing the location area identifier corresponding to the target user terminal , According to the set neighboring cell rules, expand a neighboring cell radius around, and page the user terminal in the expanded paging range.
The method for paging optimization based on a satellite network terminal according to claim 7, wherein the method for paging the user terminal in the expanded paging range is: querying multiple satellites covering part of the expanded paging range, Paging messages are delivered through the plurality of satellites and corresponding base stations.