CN1992919B - Method for Realizing Multi-Node Load Balance in Mobile Communication System - Google Patents

Abstract

The present invention provides a method for realizing multi-node load balancing in a mobile communication system. The mobile communication system includes at least a wireless access network and a core network, and the core network has at least one core network node. The method includes: The access network selects an effective core network node according to the destination identification indication from the mobile terminal; the wireless access network delivers the access signaling to the effective core network node according to the route corresponding to the effective core network node; the effective core network node guides Introduce the subsequent connection process of the mobile terminal. Since the present invention adopts the technical scheme that the wireless access network selects an effective core network node according to the purpose identification indication from the mobile terminal, so selecting an effective core network node as the route of the mobile terminal can make the mobile terminal quickly communicate with the core network Nodes are connected to service nodes.

Description

Method for realizing multi-node load balance in mobile communication system

Technical Field

The invention relates to a load balancing technology, in particular to a multi-node load balancing method in a mobile communication system.

Background

At present, load balancing technology is introduced into various mobile communication systems, and the stability and the security of the communication systems are greatly improved due to the addition of the technology.

For example, 3GPP (third generation partnership project) has started to introduce Iu Flex technology (technology in which a RAN node is connected to multiple CN nodes) in Release 5, which solves the technical problem that RAN (radio access network) is connected to multiple peer nodes in the same CN (core network) domain. The Iu Flex technique is to break the limitation that one RAN node can only be connected to one MSC server and SGSN (serving general packet radio service support node) in GSM (global system for mobile communications) and UMTS (universal mobile telecommunications system) networks. The Iu Flex technology improves network performance in several aspects, firstly, it reduces signaling overhead when the user roams; secondly, the network load is uniformly distributed and backed up in the CN entity; again, it provides an implementation for system capacity expansion.

Current Iu Flex technology has specified that the RNC should be able to handle exceptions caused by some CN node overload or other reasons. However, the load balancing principle of the current Iu Flex technology is only used when an RNC (radio Network controller) cannot interpret an IDNNS (Intra Domain NASNode Selector) value in initial direct transmission signaling of a Uu interface (interface where a mobile terminal is connected to a RAN), or an NRI (Network Resource Identifier) value derived from an IMSI (international mobile subscriber identity) cannot be mapped to a valid CN node. UTRAN (universal mobile telecommunications system terrestrial radio access network) uses the cell "Intra Domain NAS node Selector" for routing to a target CN Domain among a plurality of CN nodes, the detailed description of the "Intra Domain NAS node Selector" is referred to 3GPP TS25.33110.3.1.6; the "Network Resource Identifier" uniquely identifies a single CN node in the CN node shared pool, and the detailed description of the "Network Resource Identifier" is referred to in 3GPP TS23.2364.3.

Taking the multi-node load balancing method shown in fig. 1 as an example, in steps S101 and S102, the mobile terminal accesses the RAN, and the RNC analyzes an access signaling; step S103 is entered, RNC analyzes whether the identification indication of NRI in the signaling is valid; if yes, step S105 is carried out, and a core network entity is selected; if not, the step S104 is carried out, the RNC carries out load balancing operation, and then the step S105 is carried out; finally, step S106 is entered, and the selected core network entity directs the connection.

As can be seen from the technical solution shown in fig. 1, the RNC performs the load balancing operation only when the NRI identifier indicates invalidity, and only selects a valid core network entity, rather than selecting an optimal core network entity from a plurality of valid core network entities. In other words, the load balancing mechanism of the current UMTS system Iu Flex technology is only applicable to the following situations: the RNC cannot interpret the IDNNS value in the initial direct transfer signaling of the Uu interface or the NRI value derived from the IMSI by the RNC cannot be mapped to a valid CN node. Generally, the above signaling received by the RNC originates from a UE (user equipment) that does not support the Iu Flex feature, so the current technology only solves the load balancing of the traffic triggered by this part of the UE in the CN node shared pool.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a method for implementing multi-node load balancing in a mobile communication system, so as to implement load balancing of traffic triggered by all UEs in a core network node shared pool in the mobile communication system.

The invention provides a method for realizing multi-node load balance in a mobile communication system, wherein the mobile communication system at least comprises a wireless access network and a core network, the core network is provided with at least one core network node, and the method comprises the following steps: the wireless access network determines that the target identification indication can be analyzed and is effective according to the target identification indication from the mobile terminal, and selects an effective core network node according to the load of each core network node when judging that the core network node indicated by the target identification indication is in a service overload state; or, the wireless access network determines that the target identification indication can be analyzed and is effective according to the target identification indication from the mobile terminal, and selects an effective core network node according to the load of each core network node; the wireless access network delivers the access signaling to the effective core network node according to the route corresponding to the effective core network node; and guiding the subsequent connection process of the mobile terminal by the effective core network node.

If the wireless access network can not analyze the target identification indication or the target identification indication can not be mapped to any core network node which has a direct connection relation with the wireless access network, the wireless access network selects an effective core network node according to the load of each core network node.

If the destination identifier indicates mapping to a core network node that is not in a traffic overload state, the radio access network may select the core network node as the active core network node.

If the destination identifier indicates that the target identifier is mapped to a core network node which is not in a service overload state, the radio access network can select an effective core network node according to the load of each core network node.

Each core network node may send a load level report to the radio access network using a fixed time period, or according to a change in the load state, or when preparing to provide service for a new mobile terminal, and the radio access network may select an active core network node according to the load level report.

The wireless access network firstly excludes the selection of the core network node at the failure level or the full load level; the wireless access network selects the core network node with the minimum load level as an effective core network node; and if the plurality of core network nodes are in the minimum load level, the wireless access network randomly selects one of the core network nodes in the minimum load level as an effective core network node.

In addition, the radio access network sends a request for inquiring the load level to a plurality of core network nodes by using a fixed time period or when the radio access network receives a connection request of the mobile terminal and one of the plurality of core network nodes, and selects an effective core network node according to the obtained load level report.

The wireless access network firstly excludes the selection of the core network node at the failure level or the full load level; the radio access network can select the core network node with the minimum load level as an effective core network node; and if the plurality of core network nodes are in the minimum load level, the wireless access network randomly selects one of the core network nodes in the minimum load level as an effective core network node.

The invention adopts the technical proposal that the wireless access network selects the effective core network node according to the destination identification indication from the mobile terminal, so the effective core network node is selected as the route of the mobile terminal, and the mobile terminal can be quickly connected with the service node connected with the core network node.

The invention adopts the technical scheme that the target identification indication is ignored and the effective core network node is reselected aiming at the special conditions that the wireless access network can not analyze the target identification indication from the mobile terminal or the core network node pointed by the identification indication is overloaded with service and the like.

Drawings

Fig. 1 is a flowchart of a conventional method for implementing multi-node load balancing.

Fig. 2 is a flowchart of a first embodiment of the present invention.

Fig. 3 is a flowchart further illustrated in step S201 in fig. 2.

Fig. 4 is a first flowchart further explained in step S2015 and step S2016 in fig. 3.

Fig. 5 is a second flowchart further explained in step S2015 and step S2016 in fig. 3.

FIG. 6 is a diagram of the Iu Flex system structure in LTE/SAE according to the second embodiment of the present invention.

Fig. 7 is a flowchart of a second embodiment of the present invention.

Fig. 8 is a flowchart of the MME/UPE node notifying the CP Anchor of its current load status according to the second embodiment of the present invention.

Fig. 9 is a flowchart of the load balancing operation performed by the CP Anchor according to the second embodiment of the present invention.

Detailed Description

The following detailed description of the preferred embodiments of the present invention will be made with reference to the accompanying drawings. It is to be noted at first that the meanings of terms, words and claims used in the present invention are not limited to only the literal and ordinary meanings thereof, but also include meanings and concepts conforming to the technology of the present invention because we, as the inventor, appropriately give definitions of terms in order to describe our invention most appropriately. Accordingly, the arrangements shown in the present specification and drawings are only preferred embodiments of the invention and are not intended to list all of the technical features of the invention. It will be appreciated that there are a variety of equivalents and modifications which may be substituted for those of our scheme.

Fig. 2 is a flowchart of a first embodiment of the present invention, in which a mobile communication system at least includes a radio access network and a core network, and the core network has at least one core network node. As shown in the figure, in step S201, the radio access network selects an effective core network node according to the destination identifier indication from the mobile terminal, and in this process, the radio access network needs to identify the destination identifier of the mobile terminal, and then selects an effective core network node according to the identification result; step S202 is entered, after the wireless access network selects the core network node for the mobile terminal, the wireless access network delivers the access signaling to the effective core network node according to the route corresponding to the effective core network node, namely requests to connect with the core network node; and finally, step S203 is carried out, and after the effective core network node receives the request, the subsequent continuing process of the mobile terminal is guided.

The steps disclosed in fig. 2 are only necessary features for implementing the method of the present invention. Step S201 in fig. 2 will now be further described to facilitate the implementation of the present invention by those of ordinary skill in the art.

Fig. 3 is a flowchart further illustrated in step S201 in fig. 2. In step S2011, the radio access network identifies a destination identifier indication originating from the mobile terminal; step S2012 is entered, the wireless access network judges whether the identification indication can be analyzed, if yes, step S2013 is entered, otherwise, step S2015 is entered, if no, the node in the wireless access network can only be connected to a core network node; in step S2013, after determining that the id indication can be resolved, the radio access network further needs to determine validity of the id indication, if valid, the id indication can be mapped to one of the nodes in the core network, and then step S2014 is performed, otherwise, the id indication cannot be mapped to any node in the core network, and then step S2015 is performed; in step S2014, the radio access network further needs to continuously determine whether the identifier indicates that the core network node is in a traffic overload state, if so, step S2015 is performed, otherwise, step S2016 is performed; in step S2015, if the radio access network cannot resolve the identifier indication, or the identifier indication is invalid, or the core network node pointed by the identifier indication is in a traffic overload state, the radio access network needs to compare the load of each node in the core network; in step S2016, the radio access network selects an effective core network node for the mobile terminal according to the result of comparing the load amounts.

It should be noted that the radio access network may not need to determine whether the core network node pointed by the identifier indication is in a traffic overload state, that is, whether the core network node pointed by the identifier indication is in the overload state, the radio access network compares the load of each core network node, and selects the most suitable node from the load to connect with the mobile terminal.

The method of load balancing of the present invention will now be further described.

Fig. 4 is a first flowchart further explained in step S2015 and step S2016 in fig. 3. In step S401, each core network node sends a load level report to the radio access network with a fixed time period, or according to a change in load status, or when preparing to provide service for a new mobile terminal. In this embodiment, the load level represents the load state of the core network node, the larger the load level is, the larger the representative traffic load is, and the fixed time period may be a fixed interval time, for example, each core network node sends a load level report to the radio access network every 5 seconds. Proceeding to step S402, the radio access network saves and updates the load level of each node. And step S403 is performed, in which the radio access network compares the load levels of the current core network nodes, during which the radio access network first excludes the core network nodes at the failure or full load level, that is, the radio access network does not consider selecting these nodes as valid nodes connected to the mobile terminal, and then determines the node with the minimum load level as the valid node for connection by comparing the load levels of multiple nodes, and in addition, if the load levels of multiple nodes are at the minimum load level, the radio access network randomly determines one of these nodes as the valid node. And finally, entering step S404, after comparing the load levels of the nodes, the radio access network selects the node at the minimum load level as an effective node.

In fig. 4, the radio access network obtains the information of the core network node load state by sending a load state report through the core network node, and in fact, the radio access network obtains the information of the core network node load state by other methods.

Fig. 5 is a second flowchart further explained in step S2015 and step S2016 in fig. 3. As shown in the figure, in step S501, when the radio access network uses a fixed time period or receives a connection request from the mobile terminal to one of a plurality of core network nodes, the radio access network sends a request for querying a load level to all the core network nodes to obtain a load level report. As in the embodiment of fig. 4, the radio access network may issue a request to all core network nodes to query the load level at intervals. Proceeding to step S502, the radio access network saves and updates the load level of each node. And step S503 is performed, the radio access network compares the current load levels of the core network nodes, in this process, the radio access network first excludes the core network nodes at the failure or full load level, that is, the radio access network does not consider selecting these nodes as the effective nodes connected to the mobile terminal, and then determines the node with the minimum load level as the effective node connected by comparing the load levels of the plurality of nodes, and in addition, if the load levels of the plurality of nodes are at the minimum load level, the radio access network randomly determines one of these nodes as the effective node. And finally, entering step S504, after comparing the load levels of the nodes, the radio access network selects the node at the minimum load level as an effective node.

The following describes a preferred embodiment of the method for implementing multi-node load balancing according to the present invention.

The present embodiment is applicable to all mobile communication systems having Iu Flex technology (technology in which RAN nodes are connected to multiple CN nodes), and for convenience of description, the system structure of LTE/SAE (long term evolution/system architecture evolution) is taken as an example, and at present, the system structure of LTE/SAE is not completely fixed. There are two main types of connection relationships between E-UTRAN (evolved universal mobile telecommunications system terrestrial radio access network) and evolved core network entities, namely: one is to implement a similar three-layer connection and the other is to implement a two-layer connection. Fig. 6 shows a connection relationship in which the control plane is separated from the user plane, i.e., a first connection relationship. As shown in fig. 6, the E-Node B604 (Evolved Node B) is connected to an Anchor Node CP Anchor 603 (Control Plane Anchor) of the Evolved access network 601 at a Control Plane, and the CP Anchor 603 transfers the Control signaling of the E-Node B604 to the Evolved Core network 602(Evolved Core). In the evolved core network 602, directly connected to the evolved access network 601, are MME/UPE (mobility Management entity/user Plane entity) 605, which are responsible for mobility Management and user Plane control, respectively, MME (mobility Management entity) functions are assumed by SGSN and GGSN (general packet radio service gateway support node) in UMTS, and UPE (user Plane entity) functions are assumed by GGSN in UMTS.

The second connection relationship described above is that the function of the CP Anchor 603 in fig. 6 is directly implemented in the E-Node B604 as a logical entity. The third connection relationship is that the CP Anchor 603 is implemented by an entity of the MME/UPE 605 therein. The solution described in this embodiment is based on the network structure connection relationship in fig. 6, but the technical solution of this embodiment can be applied to other network structure connection relationships similar to fig. 6 with slight modifications, and therefore, such derivative applications are also within the scope of the present invention. For a detailed description of "Mobility management Entity" and "User Plane Entity", see 3GPP TR23.8823.1.

In fig. 6, four evolved core network 602 entity combinations MME/UPE 605 connected to an evolved access network 601 are shown, and logical functions MME/UPE may be co-located in the same physical functional entity or may be separately arranged, and the four core network entity groups MME/UPE 605 in fig. 6 belong to the same operator. To implement Iu Flex, E-NodeB 604 in evolved access network 601 needs to implement user plane connection with four core network entity groups MME/UPE 605, as shown by the dashed lines in the figure; the CP Anchor 603 in the evolved access network 601 is to implement control plane connection with four core network entity groups MME/UPE 605, as shown by the upper four solid lines in the figure. In addition, the E-Node B604 in the evolved access network 601 has a direct connection relationship with the CP Anchor 603.

When accessing a mobile terminal, an entity of an evolved access network 601 standardized by LTE/SAE needs to select an entity serving a current mobile terminal from a core network node shared pool in an evolved core network 602, and specifically, mainly represents selection of an MME/UPE 605 node. The mobile terminal has some identity (e.g., NRI) when accessing the evolved access network 601 system to indicate the MME/UPE 605 node that the mobile terminal prefers to access.

In the conventional access situation, namely when the MME/UPE node indicated by the mobile terminal is not in a traffic overload state, and the system fails for other reasons, the CP Anchor directly selects the MME/UPE node to which it is mapped according to the identifier (e.g. NRI) indicated by the mobile terminal, and delivers the access signaling to the MME/UPE node according to the route corresponding to the MME/UPE node, and then the MME/UPE node guides the subsequent connection process of the mobile terminal.

In the case of an irregular access, that is, when the MME/UPE node indicated by the mobile terminal has been overloaded or the system fails due to other reasons, the CP Anchor ignores the identifier (e.g., NRI) indicated by the mobile terminal, and then performs a load balancing operation, selects a valid MME/UPE node from the other MME/UPE node group having a direct connection relationship with the CP Anchor, and delivers the access signaling to the MME/UPE node according to the route corresponding to the MME/UPE node, and then the MME/UPE node guides the subsequent connection process of the mobile terminal.

In an extreme case, that is, when a CP Anchor parses an access signaling of a mobile terminal, if it is found that a core network entity identifier (e.g., NRI) indicated by the mobile terminal cannot be mapped to any MME/UPE node having a direct connection relationship with the CP Anchor, a load balancing operation should also be performed, a valid MME/UPE node is selected from an MME/UPE node group having a direct connection relationship with the CP Anchor, and the access signaling is delivered to the MME/UPE node according to a route corresponding to the MME/UPE node, and then the MME/UPE node guides a subsequent connection process of the mobile terminal.

The processing procedure of the flag by the CP Anchor is described below with reference to the flowchart shown in fig. 7.

In step S701, the mobile terminal accesses the LTE/SAE system; step S702 is entered, the CP Anchor analyzes the access signaling, especially needs to analyze the NRI identification indication in the signaling; in step S703, the CP Anchor determines whether the NRI flag indication is valid, that is, the CP Anchor determines whether the NRI flag indication can be mapped to an MME/UPE node in the core network, if so, step S704 is performed, otherwise, step S706 is performed; in step S704, CPAnchor selects a corresponding MME/UPE node in the core network according to the NRI indication; step S705 is entered again, the CP Anchor still needs to continuously determine whether the MME/UPE node is valid, that is, whether the node is in a service overload state or in a system failure state due to other reasons, if yes, step S707 is entered, otherwise, step S706 is entered; in step S706, the CP Anchor performs load balancing operation, that is, determines the load states of all MME/UPE nodes in the core network, and prepares for the next step S707; step S707 is entered, CPANCHor selects effective core network nodes; finally, step S708 is entered, and the selected node directs the subsequent connection of the terminal.

In this embodiment, the CP Anchor determines whether a certain MME/UPE node belongs to the above-mentioned "traffic overload" or "system failure due to other reasons" according to the signaling indication periodically transmitted by the MME/UPE node. In the following, with reference to fig. 8, how the MME/UPE node notifies the CP Anchor of its current system status will be further described.

Let A, B, C and D denote the load condition of core network entity node MME/UPE in turn, where A load level lowest denotes that the system has only 25% load, D load level highest denotes that the system has 100% load, and B and C are centered. In addition, X represents that the core network entity node MME/UPE is in a failure state. The MME/UPE node reports the load state of the MME/UPE node to the CP Anchor periodically, and the periodic reporting can refer to the periodic reporting according to the rotation of a fixed time slice; or, the MME/UPE reports when it finds that its load status changes, for example, its load level changes from B to C; it may also be understood that the MME/UPE node reports when it is ready to serve a new mobile terminal in the shared pool.

In the process, the CP Anchor stores the load report result of the MME/UPE node and dynamically updates the state thereof according to the report. The normal MME/UPE node should be in one of the four states A, B, C and D. The CP Anchor determines whether a core network entity node is in the X state according to an abnormal flow, for example, according to whether link communication between the CP Anchor and the core network entity node is interrupted.

As shown in fig. 8, in step S801, the CP Anchor starts running; step S802 is entered, the CP Anchor initializes the load level table of each MME/UPE node, for example, the initial values are all set as A load level; in step S803, the CP Anchor needs to determine whether a load report or a report of system failure is received, if not, continue to step S803, otherwise, enter step S804; in step S804, the CP Anchor further needs to determine whether the load of each node changes, if not, the process returns to step S803, otherwise, the process proceeds to step S805, in which the CP Anchor updates the load level table, updates the table entry of the corresponding node, and after the step is completed, the process returns to step S803.

Next, referring to fig. 9, the process of the CP Anchor performing the load balancing operation will be described.

The CP Anchor should first exclude MME/UPE nodes at D and X load levels when performing load balancing operations. Then, the node with the lowest load level is selected from the remaining nodes. And if the load levels of a plurality of nodes are at the minimum level, randomly selecting the nodes.

As shown in fig. 9, in step S901, the CP Anchor starts to perform a load balancing operation; entering step S902, the CP Anchor inquires the load level table of the MME/UPE node, namely, the load level of each node; in step S903, the CP Anchor determines whether there is a node at the D/X load level, if so, step S904 is performed, otherwise, step S905 is performed; in step S904, if there are nodes in the core network at the D/X load level, the CP Anchor excludes the selection of these nodes; step S905 is entered, the CP Anchor continues to select the node with the minimum load level from the rest nodes; in step S906, the CP Anchor determines whether there are multiple nodes that are at the minimum load level, if so, step S907 is entered, otherwise, step S901 is returned; in step S907, the CP Anchor determines candidate nodes from all nodes with the minimum load level in a random manner; finally, the process proceeds to step S908, where CPAnchor ends the load balancing operation.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be construed as the protection scope of the present invention.

Claims (8)

1. A method for implementing multi-node load balancing in a mobile communication system, the mobile communication system at least including a radio access network and a core network, the core network having at least one core network node, the method comprising:

A. the wireless access network determines that the target identification indication can be analyzed and is effective according to the target identification indication from the mobile terminal, and selects effective core network nodes according to the load of each core network node when judging that the core network nodes indicated by the target identification indication are in a service overload state; or,

the wireless access network determines that the target identification indication can be analyzed and is effective according to the target identification indication from the mobile terminal, and selects effective core network nodes according to the load of each core network node;

B. the wireless access network delivers an access signaling to the effective core network node according to the route corresponding to the effective core network node;

C. and guiding the subsequent connection process of the mobile terminal by the effective core network node.

2. The method for implementing multi-node load balancing in a mobile communication system as claimed in claim 1, further comprising,

and if the wireless access network cannot analyze the target identification indication or the target identification indication cannot be mapped to any core network node which has a direct connection relationship with the wireless access network, the wireless access network selects the effective core network node according to the load of each core network node.

3. The method for implementing multi-node load balancing in a mobile communication system according to claim 1, wherein the radio access network selects a core network node that is not in a traffic overload state as the active core network node if the destination identifier indicates a mapping to the core network node.

4. The method as claimed in claim 1, wherein if the destination identifier indicates a mapping to a core network node not in a traffic overload state, the radio access network selects the valid core network node according to the load capacity of each core network node.

5. A method for multi-node load balancing in a mobile communications system according to claim 2 or 4, characterised in that each core network node sends a load level report to the radio access network with a fixed period of time, or upon a change in load status, or when preparing to serve a new mobile terminal, and the radio access network selects the active core network node based on the load level report.

6. The method for implementing multi-node load balancing in a mobile communication system according to claim 5,

the radio access network excluding selection of core network nodes at a failure level or a full load level; and the number of the first and second groups,

the wireless access network selects the core network node with the minimum load level as the effective core network node;

and if the plurality of core network nodes are in the minimum load level, the wireless access network randomly selects one of the core network nodes in the minimum load level as the effective core network node.

7. The method according to claim 2 or 4, wherein the radio access network sends a request for querying a load level to the plurality of core network nodes and selects the active core network node according to the obtained load level report, when the radio access network utilizes a fixed time period or the radio access network receives a connection request of the mobile terminal and one of the plurality of core network nodes.

8. The method for implementing multi-node load balancing in a mobile communication system according to claim 7,

the radio access network excluding selection of core network nodes at a failure level or a full load level;

the wireless access network selects the core network node with the minimum load level as the effective core network node;

and if the plurality of core network nodes are in the minimum load level, the wireless access network randomly selects one of the core network nodes in the minimum load level as the effective core network node.

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