CN114363392A - Unicast multicast switching method, system and medium for session management - Google Patents

Abstract

The present invention provides a unicast-multicast switching method, system and medium for session management. Step S11: Count the number of user equipments requesting the same content; Step S12: Compare the counted number of user equipments with the preset trigger threshold, and judge whether the trigger condition is met, and decide whether to trigger the handover according to the actual load situation of the network; Step S13: Execute the unicast-multicast switching process to complete the switching between unicast and multicast. The invention adopts a threshold setting method to ensure the stability of unicast-multicast switching, and the method of triggering unicast-multicast switching by the session management function can ensure the reliability of unicast-multicast switching in the 5G system. Service continuity is guaranteed during multicast handover.

Description

Unicast multicast switching method, system and medium for session management

technical field

The present invention relates to the field of communication technologies, and in particular, to a unicast-multicast switching method, system and medium for session management. In particular, it relates to a method for triggering a unicast-multicast handover by a session management function in a 5G system.

Background technique

With the rapid development of the Internet, a large number of multimedia services have emerged. Some of these applications allow multiple users to receive the same data at the same time, such as video-on-demand, TV broadcasting, video conferencing, online education, and interactive games. For a mobile network, if a large number of users using the same service are in the same cell, the wireless access network, especially the wireless link, can easily become a bottleneck. For example, when a major sporting event is broadcast, many fans will be watching the game on their cell phones or other mobile devices at the same time. In this case, the use of point-to-point radio bearers is very inefficient. Therefore, there is a great need for broadcast multicast services.

Multicast broadcast distribution of homogeneous content can significantly improve the utilization efficiency of air interface frequency resources. Since 3G, mobile communication networks have provided multicast broadcasting capabilities. 3GPP defined MBMS for 3G networks, and then eMBMS for 4G networks. However, these dedicated broadcasting systems have high exclusiveness to time-frequency resources and are not compatible with unicast systems. Due to factors such as mutual independence, complex technical solutions, weak demand, and unclear application scenarios, multicast broadcasting failed to achieve large-scale commercial use in the 3G and 4G eras.

This situation has changed a lot in 5G networks. For example, the live video service has become the mainstream application of the current mobile Internet, and the traffic accounts for a very large proportion. It often happens that multiple users in a certain area request the same content in the same time period. Therefore, the single cell mentioned in 5G Rel-17 Multicast services have become an important topic. In this system, unicast and multicast exist at the same time, and exclusive time-frequency resources will not be allocated for multicast, and the network will dynamically switch the unicast-multicast mode to make better use of network resources. Considering the continuity of the service, the 5G core network needs a reliable handover method, and considering the maximized user experience, the inventor proposes a method for unicast-multicast reliable handover in the 5G network.

Patent document CN107995603A (application number: 201610958518.5) discloses a capability openness implementation method and device. The network side obtains service group information transmitted by third-party services through the capability openness platform, and the network side implements groups corresponding to service groups. The network policy manages the terminals in the group, thus realizing the capability opening based on group management and satisfying the realization of differentiated services based on group services for third-party services.

SUMMARY OF THE INVENTION

In view of the defects in the prior art, the purpose of the present invention is to provide a unicast-multicast switching method, system and medium for session management.

The unicast-multicast switching method for session management provided according to the present invention includes:

Step S10: preset a trigger threshold x for switching from unicast to multicast and a trigger threshold y for switching from multicast to unicast;

Step S11: Count the number of user equipments requesting the same content;

Step S12: Compare the counted number of user equipments with a preset trigger threshold, and judge whether the trigger condition is met, and decide whether to trigger the handover according to the actual load of the network;

Step S13: Execute the unicast-multicast switching process to complete the switching between unicast and multicast.

Preferably, according to the type of session management, it is divided into unicast session management and multicast session management, and the number of user equipments managed by unicast session and multicast session is counted respectively.

Preferably, the process of switching from unicast to multicast includes the following steps:

Step S21: providing the information of the user equipment and the next generation wireless access network to the unicast session management through the access and mobility management function;

Step S22: judging whether the triggering condition is met through unicast session management, and if so, triggering the switch from unicast to multicast;

Step S23: performing interaction between unicast session management and multicast session management, and modifying the user plane function configuration of unicast session management and multicast session management;

Step S24: the multicast session management notifies the policy control function to update the policy, and sends the modification information to the access and mobility management function;

Step S25: The access and mobility management function notifies the wireless access network to switch the point-to-point/point-to-multipoint mode to complete the switch from unicast to multicast.

Preferably, the process of switching from multicast to unicast includes the following steps:

Step S31: Provide the information of the user equipment and the next generation wireless access network to the multicast session management through the access and mobility management function;

Step S32: Judging whether the triggering condition is met through multicast session management, and if so, triggering the switch from multicast to unicast;

Step S33: performing interaction between unicast session management and multicast session management, and modifying the user plane function configuration of unicast session management and multicast session management;

Step S34: the unicast session management notifies the policy control function to update the policy, and sends the modification information to the access and mobility management function;

Step S35: The access and mobility management function notifies the wireless access network to switch the point-to-point/point-to-multipoint mode to complete the switch from multicast to unicast.

Preferably, the interaction between the unicast session management and the multicast session management is performed through an N16 interface.

Preferably, the trigger threshold x and the trigger threshold y are both positive integers, and x is greater than y;

Both the trigger threshold x and the trigger threshold y are proportional to the actual load capacity of the radio access network.

Preferably, the request contents of different numbers of user equipments are compared, and if the number of user equipments is greater than or equal to the triggering threshold x, the unicast-to-multicast switching is triggered; if it is less than the triggering threshold x, the unicast-to-multicast switching is not triggered. switch;

If the number of user equipments is less than the trigger threshold y, the multicast session is ended; if it is greater than or equal to the trigger threshold y, the multicast session is maintained.

Preferably, after the switching process is completed, when the new user equipment requests content, the unicast session management and the multicast session management determine whether there is a multicast session with the same content, and if so, the multicast session management adds it to the multicast Session group; if it does not exist, unicast session management establishes a unicast session for it.

The unicast-multicast switching system for session management provided according to the present invention includes:

Module M1: preset a trigger threshold x for switching from unicast to multicast and a trigger threshold y for switching from multicast to unicast;

Module M2: Count the number of user equipments requesting the same content;

Module M3: compares the counted number of user equipments with a preset trigger threshold, determines whether the trigger condition is met, and decides whether to trigger the handover according to the actual load of the network;

Module M4: Execute the unicast-multicast switching process to complete the switching between unicast and multicast.

According to the present invention, a computer-readable storage medium storing a computer program is provided, and when the computer program is executed by a processor, the steps of the above-mentioned method are implemented.

Compared with the prior art, the present invention has the following beneficial effects:

1. A method for triggering unicast-multicast switching by a session management function in a 5G system provided by the present invention can ensure the reliability of unicast-multicast switching in the 5G system, and at the same time ensure the service during unicast and multicast switching. continuity;

2. In the aspect of threshold setting of the present invention, the setting is performed according to the actual load capacity of the NG-RAN, and the triggering threshold x of switching from unicast to multicast is greater than the triggering threshold y of switching from multicast to unicast, which reduces the cost of switching from unicast to multicast. Frequent occurrence is more conducive to the stability of network conditions.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

1 is a schematic flowchart of a specific embodiment of a method for triggering a unicast-multicast handover by a session management function in a 5G system according to the present invention;

2 is a schematic flowchart of switching from unicast to multicast according to the present invention;

3 is a schematic flowchart of switching from multicast to unicast according to the present invention;

4 is a schematic flowchart of a specific implementation manner of switching from unicast to multicast according to the present invention;

FIG. 5 is a schematic diagram of each functional connection of the present invention.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the inventive concept. These all belong to the protection scope of the present invention.

Example 1:

The present invention can further improve the reliability of unicast-multicast handover in the 5G system, and at the same time ensures the continuity of the service in the handover process and the stability of the network as a whole.

According to the present invention, a method for triggering a unicast-multicast switch by a session management function in a 5G system is provided. The SMF and the (MB-)SMF set the trigger threshold and the (MB-)SMF according to the actual load capacity of the NG-RAN. The trigger threshold for switching from multicast to unicast, and through the triggering process, reliable switching between unicast and multicast is completed.

This embodiment provides a method for triggering a unicast-multicast handover by a session management function in a 5G system, which can further improve the reliability of unicast-multicast handover in a 5G system, while ensuring the continuity of services during the handover process. and the overall stability of the network.

The specific technical solution of this example is:

In the 5G architecture, the control plane consists of AMF, SMF and PCF. The UE is connected to the NG-RAN through the air interface, and the NG-RAN is connected to the AMF through the N2 interface. This interface is used to transmit N2 Message signaling, which is used for NG-RAN. Interaction between RAN and AMF;

The UE can also be connected to the AMF through the N1 interface, which is used to transmit N1 Message signaling, which is used for the interaction between the UE and the AMF;

The AMF is connected to the SMF through the N11 interface, which is used to transmit the Namf_Communication_N1N2MessageTransfer signaling, and the AMF reports the UE and NG-RAN information to the SMF through this signaling;

The SMF is connected to the PCF through the N7 interface, which is used to transmit the Npcf_SMPolicyControl_Update signaling, which is used to update the PCF transmission policy;

The SMF and the SMF are connected through the N16 interface, which is used to transmit the N16 Message signaling, which is used for the interaction between the SMFs.

In the 5G architecture, the user plane consists of UPF and AF, the UE is connected to the NG-RAN through the air interface, and the NG-RAN is connected to the UPF through the N3 interface, which is used to transmit user data;

The UPF is connected to the AF through the N6 interface, and the AF sends data through this interface; the UPF is connected to the SMF through the N4 interface, which is used to transmit the N4 Session Modification signaling, and the SMF modifies the UPF configuration through this signaling.

As shown in FIG. 1 , a specific implementation process of a method for triggering a unicast-multicast handover by a session management function in a 5G system of the present invention includes the following steps:

Step S10, the SMF presets a trigger threshold for switching from unicast to multicast and a trigger threshold for switching from multicast to unicast;

Step S11, the SMF counts the number of UEs requesting the same content through unicast/multicast;

Step S12, the SMF judges whether the trigger condition is satisfied, and decides whether to trigger the handover according to the actual load of the network.

Step S13, the system executes the unicast-multicast switching process to complete the switching between unicast and multicast.

Specifically, as shown in FIG. 4 , the specific implementation method of switching from unicast to multicast of the present invention is as follows:

0. Initially, UE communicates with AF and receives service data through unicast mode.

1. The SMF sets a trigger threshold for switching from unicast to multicast according to the actual load capacity of the NG-RAN. If the threshold already exists, proceed to the next step.

2. The (MB-)SMF sets a trigger threshold for switching from multicast to unicast according to the actual load capacity of the NG-RAN. If the threshold already exists, proceed to the next step.

3. The AMF can obtain N1 messages such as the location of the UE in the RAN node; obtain N2 messages, such as the congestion status of the RAN; and send the information to the SMF by calling Nsmf_PDUSession_UpdateSMContext. The information includes but is not limited to unicast session ID, SUPI, the mapping relationship between UE and RAN node, the communication capability of RAN, and the availability of radio resources.

4.SMF is able to collect and forecast the needs of each content. According to the information sent by the AMF, if the number of unicast sessions carrying the same content exceeds the load capacity of the NG-RAN or the prediction range of the SMF, the SMF will trigger the switch from the unicast sending mode to the multicast sending mode.

5. The SMF provides the (MB-)SMF with information related to the unicast session.

6. The SMF configures the UPF because the unicast session is about to end.

7. SMF configuration (MB-)UPF.

8a-9a. (MB-)SMF sends unicast session ID, SUPI and information/indication about multicast (eg TMGI, (MB-)UPF) etc. to AMF through Namf_Communication_N1N2MessageTransfer, AMF sends to NG-RAN through N2Message.

10. According to the N2 Message, the NG-RAN establishes or modifies AN resources for the multicast session.

9b-8b. The NG-RAN confirms to the AMF that the handover can be achieved, and the AMF confirms to the (MB-)SMF that the handover can be achieved.

Since the switching of the transmission mode is triggered by the SMF, it is necessary to confirm the intention of the UE and count the respective numbers. If new UEs are requesting the same content, they can join the multicast session directly and the number of multicast will increase.

11a-12a. (MB-)SMF sends multicast information/indication (eg TMGI, (MB-)UPF) to AMF through Namf_Communication_N1N2MessageTransfer, and AMF sends it to UE through N1 Message.

12b-11b. Some UEs wish to switch the transmission mode and others do not agree, the UEs will intend to reply to (MB-)SMF.

13a. After counting the number of respective UEs, the (MB-)SMF informs the PCF that the transmission mode of the corresponding UE will be changed (including the SM Policy Association ID) through Npcf_SMPolicyControl_UpdateRequest, so that the PCF can update the policy.

13b. PCF replies to (MB-)SMF policy update.

14-15. The UE requests the AF for multicast mode data at the application layer. The AF updates the service and sends the data to the (MB-)SMF. (MB-)SMF sends data to NG-RAN. The NG-RAN sends data to the UE using multicast.

16. The UE requests the UPF to stop the original unicast session.

As more and more UEs drop out of the multicast session, the (MB-)SMF will decide to send data in a unicast session to the remaining UEs. Switching from multicast to unicast is easier to ensure service continuity than switching from unicast to multicast.

Figure 5 is a schematic diagram of each functional connection of the present invention:

Access and Mobility Management Function (AMF): Responsible for user access and mobility management.

Session Management Function (SMF): Provides session management for UE sessions, IP address allocation and management, and UPF selection and control. (MB-) indicates that the SMF is used to manage a Multicast Broadcast (MulticastBroadcast) session.

Policy Control Function (PCF): responsible for UE access policy and quality of service (Quality of Service, QoS): responsible for generation of UE access policy and QoS flow control policy.

User Plane Function (UPF): Provides user plane functions such as forwarding, processing, connection with AF, session anchor, and QoS policy enforcement of user packets. (MB-) indicates that the UPF is used to manage a Multicast Broadcast (MulticastBroadcast) session.

Radio Access Network (RAN): The 5G access network includes the Next Generation Radio Access Network (NG-RAN) or non-3GPP access connected to the 5G core network.

Application Function (AF): Interact on behalf of other control network elements of the 5G network, including providing service QoS policy requirements, routing policy requirements, etc.

User Equipment (User Equipment, UE): terminal equipment used by a user.

The 5G network architecture is designed according to the basic principle of separation of control and forwarding. According to the basic functions of network elements, it can be divided into two parts: control plane and user plane (or data plane). The user plane is responsible for forwarding and processing user packets, and mainly includes the forwarding function of the base station and one or more user functions. The control plane network element is responsible for performing various controls such as access authentication, mobility management, session management, and policy control for the UE.

Example 2:

According to the method for triggering unicast-multicast handover provided by the session management function in the 5G system, the method includes the following steps:

As shown in Figure 2, SMF triggers the process of switching from unicast to multicast, as follows:

(1) SMF sets a trigger threshold x for the unicast-to-multicast process. The threshold x is determined according to the actual load capacity of the NG-RAN. If the threshold x already exists, the next step is directly executed;

(2) The AMF provides the information of the UE and the NG-RAN to the SMF, which includes the number of connected UEs in the NG-RAN and the data content requested by the UE;

(3) SMF compares the content requested by different UEs, and judges whether the number of UEs requesting the same content is greater than or equal to the threshold x, if it is greater than or equal to the triggering threshold x, trigger the unicast-to-multicast switching, if it is less than the triggering threshold x, then Does not trigger unicast-to-multicast switching;

(4) SMF interacts with (MB-)SMF, SMF modifies UPF configuration, (MB-)SMF modifies (MB-)UPF configuration;

(5) The (MB-)SMF informs the PCF to update the policy and sends the modification information to the AMF;

(6) According to the received information, the AMF notifies the RAN to allocate relevant resources for the multicast session, switch the PTP/PTM mode, and complete the switch from unicast to multicast.

As shown in Figure 3, SMF triggers the process of switching from multicast to unicast, as follows:

(1) (MB-)SMF sets a trigger threshold y for the unicast-to-multicast process. The threshold y is determined according to the actual load capacity of the NG-RAN. If the threshold y currently exists, the next step is directly executed;

(2) The AMF provides the information of the UE and the NG-RAN to the SMF, which includes the number of connected UEs in the NG-RAN and the data content requested by the UE;

(3) (MB-)SMF judges whether the number of UEs in the current multicast session is less than the threshold y, if it is less than the trigger threshold y, the SMF decides to end the multicast session, and if it is greater than or equal to the trigger threshold y, maintain the multicast session;

(4) SMF interacts with (MB-)SMF, SMF modifies UPF configuration, (MB-)SMF modifies (MB-)UPF configuration;

(5) SMF notifies PCF to update the policy, and sends the modification information to AMF;

(6) According to the received information, the AMF notifies the RAN to modify the relevant resources of the session, switch the PTM/PTP mode, and complete the switch from multicast to unicast.

The unicast-multicast switching system for session management provided according to the present invention includes:

Module M1: preset a trigger threshold x for switching from unicast to multicast and a trigger threshold y for switching from multicast to unicast;

Module M2: Count the number of user equipments requesting the same content;

Module M3: compares the counted number of user equipments with a preset trigger threshold, determines whether the trigger condition is met, and decides whether to trigger the handover according to the actual load of the network;

Module M4: Execute the unicast-multicast switching process to complete the switching between unicast and multicast.

According to the present invention, a computer-readable storage medium storing a computer program is provided, and when the computer program is executed by a processor, the steps of the above-mentioned method are implemented.

In a method for triggering a unicast-multicast handover by a session management function in a 5G system, the SMF sets a triggering threshold according to the actual load capacity of the NG-RAN, and different NG-RANs may have different triggering thresholds. At the same time, it does not mean that a threshold needs to be set every time a handover is triggered. For a fixed NG-RAN, the trigger threshold may be a fixed value that has been preset.

Those skilled in the art know that, in addition to implementing the system, device and each module provided by the present invention in the form of pure computer readable program code, the system, device and each module provided by the present invention can be completely implemented by logically programming method steps. The same program is implemented in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, and embedded microcontrollers, among others. Therefore, the system, device and each module provided by the present invention can be regarded as a kind of hardware component, and the modules included in it for realizing various programs can also be regarded as the structure in the hardware component; A module for realizing various functions can be regarded as either a software program for realizing a method or a structure within a hardware component.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essential content of the present invention. The embodiments of the present application and features in the embodiments may be combined with each other arbitrarily, provided that there is no conflict.

Claims (10)

1. A unicast and multicast switching method for session management, comprising:

step S10: presetting a trigger threshold value x for switching unicast to multicast and a trigger threshold value y for switching multicast to unicast;

step S11: counting the number of user equipment requesting the same content;

step S12: comparing the counted number of the user equipment with a preset triggering threshold, judging whether a triggering condition is met, and determining whether to trigger switching according to the actual load condition of the network;

step S13: and executing the unicast and multicast switching flow to complete the switching between unicast and multicast.

2. The unicast and multicast switching method for session management according to claim 1, wherein the unicast session management and the multicast session management are divided according to the type of session management, and the number of the user equipments for unicast session management and multicast session management is counted respectively.

3. The unicast-multicast switching method for session management according to claim 2, wherein the unicast switching to multicast flow comprises the following steps:

step S21: providing information of user equipment and a next generation radio access network to unicast session management through an access and mobility management function;

step S22: judging whether a trigger condition is met or not through unicast session management, and if so, triggering unicast-to-multicast switching;

step S23: performing unicast session management and multicast session management interaction, and modifying the user plane function configuration of the unicast session management and the multicast session management;

step S24: the multicast session management informs the strategy control function of updating the strategy and sends the modification information to the access and mobility management function;

step S25: the access and mobility management functions inform the radio access network to switch point-to-point/point-to-multipoint modes, and switch from unicast to multicast is completed.

4. The unicast-multicast switching method for session management according to claim 2, wherein the multicast switching to unicast flow comprises the following steps:

step S31: providing information of user equipment and a next generation radio access network to multicast session management through access and mobility management functions;

step S32: judging whether a trigger condition is met or not through multicast session management, and if so, triggering multicast-to-unicast switching;

step S33: performing unicast session management and multicast session management interaction, and modifying the user plane function configuration of the unicast session management and the multicast session management;

step S34: the unicast session management informs the policy control function of updating the policy, and sends the modification information to the access and mobility management function;

step S35: the access and mobility management functions inform the radio access network to switch point-to-point/point-to-multipoint modes, and complete the switching from multicast to unicast.

5. The unicast and multicast switching method for session management according to claim 2, wherein said unicast session management and multicast session management interact with each other through an N16 interface.

6. The unicast and multicast switching method for session management according to claim 1, wherein said trigger threshold x and trigger threshold y are both positive integers, and x is greater than y;

the trigger threshold x and the trigger threshold y are both proportional to the actual load capacity of the radio access network.

7. The unicast and multicast switching method for session management according to claim 1, wherein request contents of different numbers of user equipments are compared, and if the number of user equipments is greater than or equal to a trigger threshold x, the unicast-to-multicast switching is triggered; if the value is less than the trigger threshold value x, switching from unicast to multicast is not triggered;

if the number of the user equipment is smaller than the trigger threshold y, ending the multicast session; if the value is larger than or equal to the trigger threshold y, the multicast session is maintained.

8. The unicast and multicast switching method for session management according to claim 2, wherein after the switching process is completed, when a new user equipment requests a content, the unicast session management and the multicast session management determine whether a multicast session with the same content exists, and if so, the multicast session management adds the multicast session to a multicast session group; if not, the unicast session management establishes the unicast session for the unicast session management.

9. A unicast-multicast switching system for session management, comprising:

module M1: presetting a trigger threshold value x for switching unicast to multicast and a trigger threshold value y for switching multicast to unicast;

module M2: counting the number of user equipment requesting the same content;

module M3: comparing the counted number of the user equipment with a preset triggering threshold, judging whether a triggering condition is met, and determining whether to trigger switching according to the actual load condition of the network;

module M4: and executing the unicast and multicast switching flow to complete the switching between unicast and multicast.

10. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 8.

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