WO2011143982A1

WO2011143982A1 - Radio access network node and method for sharing load between nodes

Info

Publication number: WO2011143982A1
Application number: PCT/CN2011/072798
Authority: WO
Inventors: 刘霖; 王继承; 程翔
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-05-21
Filing date: 2011-04-14
Publication date: 2011-11-24
Also published as: CN102256305A

Abstract

A radio access network node and method for sharing load between nodes are disclosed in the present invention. Connection state of a user is recovered after Radio Network Controller (RNC) load is recovered, which ensures that the user gains the best service quality. The method includes: initiating a switch process to switch the current served user equipment to a second RNC when a first RNC determines that its load exceeds a first threshold; and after completing the switch, notifying the second RNC when the first RNC determines that its load is lower than a second threshold, and then initiating, by the second RNC, a switch process to switch the user equipment back to the first RNC.

Description

Wireless access network node and method for load sharing between nodes

Technical field

The present invention relates to a mobile communication system, and more particularly to a method for wireless access network nodes in a mobile communication system and load sharing between nodes.

BACKGROUND OF THE INVENTION A system is a third generation mobile communication system using WCDMA (Wideband Code Division Multiple Access) technology, and therefore the UMTS system is also generally referred to as a WCDMA system. The UMTS system uses a similar structure to the second generation mobile communication system, including RAN (Radio Access Network) and CN (Core Network). The radio access network handles all wireless-related functions. The core network handles all voice calls and data connections in the UMTS system and implements switching and routing functions with external networks. The CN is logically divided into a CS domain (Circuit Switched Domain) and a PS Switched Domain (Packet Switched Domain). UTRAN (Universal Terrestrial Radio Access Network), CN and UE (User Equipment) constitute the entire UMTS system.

1 is a structural diagram of a UTRAN in the prior art, and the UTRAN includes one or more RNSs (Radio Network Subsystems) 11. An RNS11 consists of an RNC (Radio Network Controller) 111 and one or more NodeBs (Node Bs). The interface between the RNC and the CN is the Iu interface. The NodeB and the RNC are connected through the lub interface. The RNCs are connected through the Iur interface. The Iur interfaces can be connected through the direct physical connection between the RNCs or through the transmission network. The RNC allocates and controls the radio resources associated with it and the associated NodeB. The NodeB completes the data stream conversion between the lub interface and the Uu interface (the interface between the RNC and the UE), and also performs radio resource management.

The RNC is used to control the radio resources of the UTRAN, and mainly performs RRC (Radio Resource Control) connection establishment and release, handover, macro-level merging, and radio resource management, as follows:

1 181102454 (1) Perform system information broadcast and system access control functions;

(2) Switching and SRNC (Source Radio Network Controller) relocation and other mobility management functions;

(3) Radio resource management and control functions such as macro diversity combining, power control, and radio bearer allocation. With the increasing popularity of HSPA (High Speed Packet Access) services, the data throughput rate is getting higher and higher, and the capacity demand for RNC is getting higher and higher, especially HSPA+ (Evolved High Speed Packet Access, evolved). With the introduction of high-speed packet access, the capacity requirement for RNC is higher, and the capacity of RNC is also larger. Due to the natural distribution and mobility of the user, the RNC accessed by the UE has a large randomness, which may cause some RNCs to operate at a high load in a short period of time. This will inevitably affect the efficiency of the RNC and the data rate of the user, and dynamically consider the inter-RNC. Load sharing is becoming more and more important.

Summary of the invention

The technical problem to be solved by the present invention is to provide a wireless access network node and a method for load sharing between nodes. After the RNC load is restored, the connection state of the user is restored, and the user is guaranteed to obtain the best service quality.

To solve the above technical problem, the present invention provides a method for load sharing between nodes in a wireless access network, including:

When the first radio network controller (RNC) determines that the load exceeds the first threshold, initiates a handover procedure, and switches the currently served user equipment to the second RNC;

After the handover is completed, after the first RNC determines that the load is less than the second threshold, the second RNC is notified, and the second RNC initiates a handover process to switch the user equipment back to the first RNC.

Preferably, in the process of switching the currently served user equipment to the second RNC, the first RNC carries a handover reason in the handover request initiated by the second RNC, to indicate that the current handover is due to the The first RNC load is overloaded, and the handover request carrying the handover reason is sent to the second RNC through the core network;

After the handover of the currently serving user equipment to the second RNC, the method further includes: The second RNC records the user equipment that is switched due to the overload of the first RNC load; the second RNC, after learning that the first RNC load is less than the second threshold, overloads the recorded first RNC load The user equipment switching to the local RNC switches back to the first RNC.

Preferably, the reason for the handover is to reduce the serving RNC load.

Preferably, the second RNC comprises one or more RNCs.

To solve the above technical problem, the present invention further provides a radio access network node, including: a first module, configured to determine a load of the node when the radio access network node serves as a source radio access network node When the first threshold is exceeded, the handover process is initiated, and the currently served user equipment is switched to the target radio access network node; after determining that the load is less than the second threshold, the load information is sent to the target radio access network node;

a second module, configured to: when the radio access network node is a target radio access network node, complete a handover process of the user equipment with the source radio access network node, and send the source radio access network node to receive After the load is less than the load information of the second threshold, the handover process is initiated, and the user equipment is switched back to the source radio access network node.

Preferably, the first module comprises:

a load monitoring unit, configured to trigger a switching unit when determining that the load of the node exceeds the first threshold, and triggering a notification unit when determining that the load is less than the second threshold;

a switching unit, configured to send a handover request to the target radio access network node based on the trigger of the load monitoring unit, to switch the currently served user equipment to the target radio access network node;

And a notification unit, configured to send load information to the target radio access network node according to the trigger of the load monitoring unit, where the load information of the local node load is less than the second threshold.

Preferably, the second module comprises:

a receiving unit, configured to: after receiving the handover request sent by the source radio access network node, trigger the determining unit and the switching unit, and receive the load that is sent by the source radio access network node to be less than the second threshold After the information, the recording unit is triggered; a switching unit, configured to complete a handover of the user equipment served by the source radio access network node to the local node based on a trigger of the receiving unit; and initiate a handover process based on the triggering of the recording unit, and the user recorded by the recording unit The device switches back to the source radio access network node;

a determining unit, configured to: when the switching request received by the receiving unit has a switching cause indicating that the cause of the current switching is a load overload, triggering the recording unit;

a recording unit, configured to record, according to a trigger of the determining unit, a user equipment that is switched due to a load overload; and based on the triggering of the receiving unit, send the recorded user equipment to the switching unit, and trigger the switching unit to initiate the switching.

Preferably, the radio access network node is a radio network controller, and the target radio access network node comprises one or more radio network controllers.

The method of the invention can effectively reduce the load of the overloaded RNC, ensure the continuity of the user service, and restore the connection state of the user after the RNC load is restored, so as to ensure the user obtains the best service quality. BRIEF abstract

1 is a network structure diagram of a UTRAN in the prior art;

Figure 2 is a flow chart of Embodiment 1 of the present invention;

Figure 3 is a flow chart of Embodiment 2 of the present invention;

4 is a schematic structural diagram of a radio access network node of the present invention. Preferred embodiment of the invention

The inventive concept is: when the first RNC determines that the load exceeds a predetermined first threshold, initiates a handover procedure, and switches the currently served user equipment to the second RNC; after the handover is completed, when the first RNC determines After the load is less than the predetermined second threshold, the second RNC is notified, and the second RNC initiates a handover process, and the user equipment is switched back to the first RNC.

Specifically, when determining that the first RNC is overloaded, the first RNC selects the adjacent light-loaded RNC according to the obtained load status of the neighboring RNC, and switches the currently serving user to the selected second RNC. This article The second RNC may include one or more RNCs. That is, the first RNC can switch multiple users it serves to different second RNCs.

Preferably, the first RNC initiates the handover of the currently serving user equipment to the neighboring second RNC, and carries the handover reason in the handover request initiated by the second RNC to indicate that the handover is due to the first An RNC load is overloaded, and the handover request carrying the handover reason is sent to the second RNC through the core network; the second RNC records the user equipments that are caused by the first RNC load overload, and is notified that the first RNC load is less than After the second threshold, the user equipment that is switched to the local RNC due to the overload of the first RNC is switched back to the first RNC.

The load state of the RNC is overloaded (ie, overloaded), normal, and light load. The first threshold may be a heavy load threshold. To prevent the user from switching back to the first RNC and causing heavy load, the second threshold may be set. For the light load threshold, that is, when the load of the first RNC falls to a light load level, the user who has previously switched off is allowed to switch back.

The present invention will be further described in detail below with reference to the drawings and specific embodiments.

Example 1

In this embodiment, after the RNC load is overloaded, the HSPA+ system is used to maintain the CS voice call, and the handover process to the legacy RNC (legacy RNC, which refers to the earlier version of the RNC) supporting CS is used to reduce the load, such as Figure 2 shows:

The UE has normally accessed the RNC1 and established a call connection through the RNC1 and the network. The RNC1 can obtain the load of the adjacent RNC according to the prior art.

Step 2010: The UE establishes a normal call connection with the network;

Step 2020: The RNC1 detects the overload of the load. According to the pre-stored load information of the neighboring RNC, the RNC1 decides to switch the UE to the less-loaded RNC2. The RNC1 initiates a relocation request to the CN, where the reason for the handover is "reduce the service RNC load." The "Source RNC to Target RNC Transport Container" cell also carries the D-RNTK The Drift RNC Radio Network Temporary Identity assigned by the RNC1 for the UE, and the drifting RNC radio network temporary identifier); Step 2030: The CN initiates a heavy load to the RNC2. The positioning requirement is to notify the RNC2 of the reason for carrying the RNC1, and the reason for the handover is "reducing the service RNC load"; Step 2040: The RNC2 receives the relocation request message, and initiates a radio link setup request to the RNC1, where the RNC1 carries the D-RNTI allocated by the UE through the "Source RNC to Target RNC Transport Container"cell; Serving RNC load", RNC2 records the handover of the UE as a handover initiated for load sharing, so that after the RNC1 load is restored, the UE is switched back to RNC1;

Step 2050: After the radio link is established, the RNC1 returns a radio link setup response message to the RNC2.

Step 2060: The RNC2 receives the radio link setup response message returned by the RNC1, returns a relocation request confirmation to the CN, and accepts the relocation request;

Step 2070: The CN sends a relocation command message to the RNC1, instructing the RNC1 to initiate relocation to the UE.

Step 2080: RNC1 initiates physical channel reconfiguration to the UE, and commands the UE to perform handover. Step 2090: After the UE handover is completed, the physical channel reconfiguration complete message is returned to the RNC2.

Step 2100: The RNC2 receives the message of the UE, and returns a relocation complete message to the CN, indicating that the UE has switched to the RNC2.

Step 2110: The CN initiates an Iu release command to the RNC1.

Step 2120: RNC1 releases the Iu interface related resources, does not release the UE context, and returns to the CN to release the Iu.

Step 2130: The UE has successfully switched to the RNC2, and the call connection is maintained by the RNC2 and the network. Step 2140: The RNC2 obtains the RNC1 load recovery information through the load interaction between the RNCs. Step 2150: The RNC2 determines that the handover is caused by the load sharing according to the record. UE, RNC2 decides to switch the UE back to RNC1, and initiates a handover procedure from RNC2 to RNC1;

The switching process from RNC2 to RNC1 is the same as the switching process between the existing RNCs, and is not described here.

Step 2160: Perform RNC2 to RNC1 handover. After the handover is completed, the UE re-accesses the network through the RNC1 to ensure that the UE can obtain the best call quality. Example 2

In this embodiment, after the RNC load is overloaded, the SRNC relocation process is used to reduce its own load, as shown in Figure 3:

Step 3010: The UE establishes a normal call connection with the network.

Step 3020: The RNC1 detects the load overload. According to the pre-stored load information of the neighboring RNC, the RNC1 decides to switch the UE to the light-loaded RNC2. The RNC1 initiates a relocation request to the CN, where the reason for the handover is "reduce the service RNC load." " ;

Step 3030: The CN initiates a relocation request to the RNC2, and the reason for carrying the RNC1 is also notified to the RNC2, and the reason for the handover is "reducing the service RNC load";

Step 3040: The RNC2 receives the relocation request message, and initiates a radio link setup request to the RNC1. According to the handover reason, "reducing the service RNC load", the RNC2 records that the handover of the UE is a handover initiated for load sharing, so that After the RNC1 load is restored, the UE is switched back to the RNC1; Step 3050: After the radio link is established, the RNC1 returns a radio link setup response message to the RNC2;

Step 3060: The RNC2 receives the radio link setup response message returned by the RNC1, returns a relocation request confirmation to the CN, and accepts the relocation request;

Step 3070: The CN sends a relocation command message to the RNC1, instructing the RNC1 to initiate relocation to the UE.

Step 3080: RNC1 initiates physical channel reconfiguration to the UE, and commands the UE to perform handover. Step 3090: The UE handover is completed, and the physical channel reconfiguration complete message is returned to the RNC2.

Step 3100: The RNC2 receives the message of the UE, and returns a relocation complete message to the CN, indicating that the UE has switched to the RNC2.

Step 3110: The CN initiates an Iu release command to the RNC1.

Step 3120: RNC1 releases the Iu interface related resources, does not release the UE context, and returns to the CN to release the Iu.

Step 3130: The UE has successfully switched to the RNC2, and the call connection is maintained through the RNC2 and the network. Step 3140: The RNC2 obtains the information about the RNC1 load recovery by using the load interaction between the RNCs. Step 3150: The RNC2 determines, according to the record, the UE that is handed over due to the load sharing, and the RNC2 decides to switch the UE back to the RNC1, and initiates the handover process of the RNC2 to the RNC1. ;

Step 3160: Perform RNC2 to RNC1 handover. After the handover is completed, the UE re-accesses the network through RNC1 to ensure that the UE can obtain the best call quality.

As shown in FIG. 4, the radio access network node implementing the above method includes a first module 41 and a second module 42, wherein:

The first module is configured to: when the wireless access network node is used as the source wireless access network node, when determining that the load of the node exceeds the first threshold, initiate a handover process, and switch the currently served user equipment to the target wireless access. a network node, after determining that the load is less than the second threshold, sending load information to the target radio access network node;

The second module is configured to: when the radio access network node is a target radio access network node, complete a handover process of the user equipment with the source radio access network node, and receive the source radio access network node After the sent load is less than the load information of the second threshold, the handover process is initiated, and the user equipment is switched back to the source radio access network node.

Preferably, the first module 41 includes a load monitoring unit 411, a switching unit 412, and a notification unit 413, where:

The load monitoring unit is configured to trigger the switching unit when determining that the load of the node exceeds the first threshold, and trigger the notification unit when determining that the load is lower than the second threshold;

The switching unit is configured to send a handover request to the target radio access network node to switch the currently served user equipment to the target radio access network node according to the trigger of the load monitoring unit; and the notification unit is configured to be based on the load monitoring unit Triggering, sending load information to the target radio access network node, where the information that the local node load is less than the second threshold is carried.

Preferably, the second module 42 includes a receiving unit 421, a switching unit 422, a determining unit 423, and a recording unit 424, where:

a receiving unit, configured to touch after receiving a handover request sent by the source radio access network node The sending determining unit and the switching unit, after receiving the load information sent by the source radio access network node and having a load less than the second threshold, triggering the recording unit;

a switching unit, configured to complete, according to a trigger of the receiving unit, a handover of the user equipment served by the source radio access network node to the local node; and, according to a trigger of the recording unit, initiate a handover process, and the user equipment recorded by the recording unit Switching back to the source radio access network node;

a determining unit, configured to determine that the switching request received by the receiving unit has a switching cause indicating that the cause of the current switching is a load overload, triggering the recording unit;

The recording unit is configured to record the user equipment that is switched due to the overload of the load based on the trigger of the determining unit; and based on the triggering of the receiving unit, send the recorded user equipment to the switching unit, and trigger the switching unit to initiate the switching.

One of ordinary skill in the art will appreciate that all or a portion of the steps above may be accomplished by a program to instruct the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

It is a matter of course that the invention may be embodied in various other forms and modifications without departing from the spirit and scope of the invention.

Industrial applicability

The method for the wireless access network node and the load sharing between the nodes provided by the invention can effectively reduce the load of the overloaded RNC, ensure the continuity of the user service, and restore the connection state of the user after the RNC load is restored, thereby ensuring the best user. Quality of business.

Claims

Claim

A method for load sharing between nodes of a wireless access network, comprising:

2. The method of claim 1 wherein:

The handover request sent by the first RNC to the second RNC is carried in the handover request initiated by the first RNC, and the handover request is sent to the second RNC to indicate that the handover is due to the first RNC. The load is overloaded, and the handover request carrying the handover reason is sent to the second RNC through the core network;

After the switching of the currently served user equipment to the second RNC, the method further includes:

The second RNC records the user equipment that is switched due to the overload of the first RNC load; the second RNC, after learning that the first RNC load is less than the second threshold, overloads the recorded first RNC load The user equipment switching to the local RNC switches back to the first RNC.

3. The method of claim 2, wherein:

The reason for the handover is to reduce the service RNC load.

4. The method of claim 1 or 2 or 3, characterized by:

The second RNC includes one or more RNCs.

5. A wireless access network node, comprising:

a first module, configured to: when the wireless access network node acts as a source radio access network node, when determining that the load of the node exceeds the first threshold, initiate a handover process, and switch the currently served user equipment to the target wireless connection. Entering a network node; after determining that the load is less than the second threshold, transmitting load information to the target radio access network node;

a second module, configured to complete a handover process of the user equipment with the source radio access network node when the radio access network node is the target radio access network node, and receive the source without After the load sent by the line access network node is less than the load information of the second threshold, the handover process is initiated, and the user equipment is switched back to the source radio access network node.

6. The node of claim 5, wherein the first module comprises:

7. The node according to claim 6, wherein the second module comprises:

a receiving unit, configured to: after receiving the handover request sent by the source radio access network node, trigger the determining unit and the switching unit, and receive the load that is sent by the source radio access network node to be less than the second threshold After the information, the recording unit is triggered;

a switching unit, configured to complete a handover of the user equipment served by the source radio access network node to the local node based on a trigger of the receiving unit; and initiate a handover process based on the triggering of the recording unit, and the user recorded by the recording unit The device switches back to the source radio access network node;

8. The node of claim 5 or 6 or 7, wherein:

The radio access network node is a radio network controller, and the target radio access network node includes one or more radio network controllers.