A Method for Establishing a Multi-Channel PDU Session

Abstract

The present invention discloses a method for establishing a multi-channel PDU session. Based on a PDU session manager with a built-in PDU session connection pool, the PDU session manager introduces a connection timer, a connection counter, and an overrun timer. The method for establishing a multi-channel PDU session includes: the PDU session manager checks whether the session exists in the PDU session connection pool according to a PDU session establishment request from an upper-layer application, and decides whether to return a PDU session establishment response according to the counts of the connection timer, the connection counter, and the overrun timer; the PDU session manager starts the connection timer first according to a PDU session disconnection request from an upper-layer application and returns a PDU session disconnection response. The present invention avoids the terminal from frequently releasing data connections, and avoids the terminal from being set as a blacklist, reducing the impact on data connections.

Description

Technical Field

[0001] The present invention relates to the field of vehicle networking, and particularly to a method for establishing multiple PDU sessions. Background Art

[0002] At present, intelligent connected vehicles usually require multiple mobile data connections to meet different types of in-vehicle networking requirements. Taking 5G connected vehicles as an example, typical requirements include 4 or more DNNs to meet different PDU session establishment requests. A typical DNN (Data Network Name) configuration is as follows: 1. IMS (IP Multimedia Subsystem) DNN, mainly used for VoLTE (Voice over LTE) or VoNR (Voice over New Radio based on 5G) voice calls and short message services; 2. DNN1, used for data transmission of high security levels such as vehicle enterprise data collection and vehicle control; 3. DNN2, used for map navigation and audio-visual entertainment; 4. DNN3, used for scenarios such as WIFI hotspots or edge computing. The terminal uses the above DNNs to establish PDU sessions according to the needs of the application layer.

[0003] In order to prevent network impacts caused by abnormal terminals repeatedly connecting to the network, the mobile communication network usually adopts certain protection measures. For example, terminals that frequently register or initiate PDU session establishment requests are set as blacklisted, and corresponding operations are prohibited for a period of time. When the terminal continuously retries the PDU session establishment request, it will cause the terminal to be unable to restore the data connection function for a long time. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for establishing multiple PDU sessions, which can avoid the terminal from frequently releasing the data connection, prevent the terminal from being set as blacklisted, and reduce the impact on the data connection.

[0005] The technical solution for achieving the above purpose is as follows:

[0006] A method for establishing multiple PDU sessions, based on a PDU session manager with a built-in PDU session connection pool. The PDU session manager introduces a connection timer, a connection counter, and an overrun timer. The method for establishing multiple PDU sessions includes:

[0007] The PDU session manager checks whether the PDU session exists in the PDU session connection pool according to the PDU session establishment request from the upper-layer application, and decides whether to return a PDU session establishment response according to the counting of the connection timer, the connection counter, and the overrun timer;

[0008] The PDU session manager starts the connection timer first according to the PDU session disconnection request from the upper-layer application, and returns a PDU session disconnection response.

[0009] Preferably, the PDU session manager checks whether the session exists in the PDU session connection pool according to the PDU session establishment request from the upper-layer application, and decides whether to return a PDU session establishment response according to the counting of the connection timer, connection counter, and overrun timer, including:

[0010] The PDU session manager checks whether the session exists in the PDU session connection pool according to the DNN name in the PDU session establishment request. If it exists, the connection timer of the session is reset, and a PDU session establishment response is returned; if it does not exist, the PDU session manager first checks whether the overrun timer has been started. If the overrun timer has been started, a PDU session establishment rejection is returned. If the overrun timer has not been started, the number of connection establishments within the window period including the current connection establishment is calculated;

[0011] The PDU session manager determines whether the number of connection establishments has reached the limit threshold. If it has reached the limit threshold, the overrun timer is started;

[0012] The DU session manager establishes a corresponding PDU session according to the DNN name, places the PDU session into the PDU session connection pool, and then returns a PDU session establishment response.

[0013] Preferably, if the upper-layer application continues to request a PDU session with the same DNN name before the connection timer times out, the PDU session manager directly returns the PDU session;

[0014] After the connection timer times out, the connection timer is ended, and the PDU session corresponding to the connection timer is disconnected.

[0015] Preferably, after the overrun timer times out, the overrun timer is ended, and the connection counter is reset.

[0016] The beneficial effects of the present invention are as follows: By setting up a PDU session connection pool on the terminal side and using a caching method, the present invention can avoid the connection number exceeding the upper limit caused by the upper-layer application frequently establishing and releasing PDU sessions. At the same time, through the request counter and data connection overrun timer, the PDU session establishment request is avoided before the protection mechanism is triggered on the network side, preventing the terminal from being set as a blacklist, ensuring that the terminal can resume responding to the PDU session establishment request from the upper-layer application in the shortest time, thereby improving the connection stability of the in-vehicle networking terminal and reducing the impact on the data connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the multi-channel PDU session establishment method in the present invention;

[0018] Figure 2 It is a schematic diagram of the PDU session establishment process in the present invention;

[0019] Figure 3 It is a schematic diagram of the PDU session disconnection process in the present invention;

[0020] Figure 4 It is a schematic diagram of the connection timer timeout action in the present invention;

[0021] Figure 5 It is a schematic diagram of the overlimit timer timeout action in the present invention. Detailed implementation manners

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] The multi-path PDU session establishment method of the present invention is based on a PDU session manager with a built-in PDU session connection pool. The PDU session manager introduces a connection timer at the PDU session level, as well as a global window period, a connection counter, and an overlimit timer, and provides a PDU session establishment request service to the upper-layer application.

[0024] Please refer to Figures 1-5 , the multi-path PDU session establishment method of the present invention includes the following steps:

[0025] One, PDU session establishment, including:

[0026] Step S1, the PDU session manager receives a PDU session establishment request from the upper-layer application;

[0027] Step S2, the PDU session manager checks whether the session exists in the PDU session connection pool according to the DNN name in the PDU session establishment request. If it exists, the connection timer T0 of the session is reset, and a PDU session establishment response is returned; if it does not exist, the PDU session manager first checks whether the overlimit timer has been started. If the overlimit timer has been started, a PDU session establishment rejection is returned. If the overlimit timer has not been started, the number of connection establishments within the window period including the current connection establishment is calculated;

[0028] Step S3, the PDU session manager determines whether the number of connection establishments has reached the limit threshold. If it has reached the limit threshold, the overlimit timer T1 is started.

[0029] Step S4, the PDU session manager establishes a corresponding PDU session according to the DNN name, places the PDU session into the PDU session connection pool, and then returns a PDU session establishment response.

[0030] Two, PDU session disconnection:

[0031] Step S5: The PDU session manager receives a PDU session disconnection request from the upper-layer application. Instead of directly disconnecting the PDU session, it first starts a connection timer T0 and returns a PDU session disconnection response. Before the connection timer T0 times out, if the upper-layer application continues to request a PDU session with the same DNN name, the PDU session is directly returned.

[0032] After the connection timer T0 times out, the connection timer T0 is ended, and the PDU (Packet Data Unit) session corresponding to this connection timer T0 is disconnected.

[0033] After the overrun timer T1 times out, the overrun timer T1 is ended, and the connection counter is reset.

[0034] The PDU session manager provides a PDU session establishment interface and a PDU session disconnection interface. To avoid concurrency issues caused by multiple upper-layer applications calling the PDU session manager, the external interfaces of the PDU session manager can be set as non-reentrant functions in implementing the present invention.

[0035] The duration of the connection timer T0 can be set to 120s. That is, if no other upper-layer application establishes a PDU session with the same DNN within 2 minutes, this connection is disconnected according to the requirements of the upper-layer application. It is recommended to set the threshold of the connection counter CNT to 4, the window length to 720s, and the duration of the connection overrun timer T1 to 720s. That is, after the number of connections reaches 4 times within 12 minutes, the PDU session manager will reject establishing a new connection within the next 12 minutes.

[0036] In summary, the connection timer at the PDU session level can avoid the upper limit of the number of connections caused by the upper-layer application frequently establishing and releasing PDU sessions, while the global connection counter and overrun timer can avoid initiating a PDU session establishment request before the protection mechanism is triggered on the network side, ensuring that the terminal can resume responding to the PDU session establishment request from the upper-layer application in the shortest time.

[0037] The above embodiments are only for illustrating the present invention and not for limiting it. Those skilled in the relevant technical fields can make various transformations or variations without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention, which should be defined by each claim.

Claims

1. A method for establishing a multi-path PDU session, based on a PDU session manager with a built-in PDU session connection pool, characterized in that The PDU session manager introduces a connection timer, a connection counter, and an overrun timer. The method for establishing a multiplexed PDU session includes: The PDU session manager checks whether the PDU session exists in the PDU session connection pool according to the PDU session establishment request from the upper-layer application, and decides whether to return a PDU session establishment response according to the counting of the connection timer, the connection counter, and the overrun timer; The PDU session manager starts the connection timer first according to the PDU session disconnection request from the upper-layer application, and returns a PDU session disconnection response; The PDU session manager checks whether the PDU session exists in the PDU session connection pool according to the PDU session establishment request from the upper-layer application, and decides whether to return a PDU session establishment response according to the counting of the connection timer, the connection counter, and the overrun timer, including: The PDU session manager checks whether the PDU session exists in the PDU session connection pool according to the DNN name in the PDU session establishment request. If it exists, the connection timer of this session is reset, and a PDU session establishment response is returned; if it does not exist, the PDU session manager first checks whether the overrun timer has been started. If the overrun timer has been started, a PDU session establishment rejection is returned. If the overrun timer has not been started, the number of connection establishments within the window period including this connection establishment is calculated; The PDU session manager determines whether the number of connection establishments has reached the limit threshold. If it has reached the limit threshold, the overrun timer is started; The DU session manager establishes a corresponding PDU session according to the DNN name, places the PDU session into the PDU session connection pool, and then returns a PDU session establishment response; Before the connection timer times out, if the upper-layer application continues to request a PDU session with the same DNN name, the PDU session manager directly returns the PDU session; When the connection timer times out, the connection timer is ended, and the PDU session corresponding to this connection timer is disconnected.

2. The method for establishing a multi-channel PDU session according to claim 1, wherein When the overrun timer times out, the overrun timer is ended, and the connection counter is reset.

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