CN1859789A - Terminal batch switching method and device in radio evolution network - Google Patents

Abstract

The invention discloses a method and a device for batch switching of terminals in a wireless evolution network. The method includes: a wireless support server acquires wireless resource management information between cells and performs batch switching decisions for wireless resource management; The base station sends a handover request signaling; after receiving the handover request signaling, the source base station selects the terminal to be handed over and finally decides whether to perform batch handover; when batch handover is required, the source base station sends a batch handover request signaling to the target base station; the target The base station analyzes the signaling and processes the terminal, and sends a batch handover confirmation request signaling to the source base station; the source base station receives the batch handover confirmation request signaling, and sends a batch handover command to the corresponding terminal; performs subsequent normal operations on each terminal Switch flow. The invention solves the problem of wireless resource management between cells in a wireless evolution network by introducing a wireless support server to trigger a batch switching process, and realizes load balancing between cells.

Description

Method and device for terminal batch handover in wireless evolution network

technical field

The present invention relates to the field of wireless mobile communication, in particular to a method and device for batch handover of terminals in a wireless evolution network.

Background technique

Universal Mobile Telecommunications System (UMTS) is a third-generation mobile communication system (3G) that adopts Wideband Code Division Multiple Access (WCDMA) air interface technology. WCDMA communication system.

Figure 1 shows the system structure diagram of UMTS. UMTS adopts a structure similar to that of the second generation mobile communication system (2G), which includes a radio access network (Radio Access Network, RAN) 20 (ie, UMTS Territorial Radio Access Network (UMTS Territorial Radio Access Network, UTRAN)) and Core Network (CN)30. Among them, the wireless access network 20 is used to handle all wireless-related functions, and the core network 30 handles all voice calls and data connections in UMTS, and implements switching and routing functions with the external network 40 . The core network 30 is logically divided into 3G circuit switched (Circuit Switched, CS) 32 and 3G packet switched (Packet Switched, PS) 34. The radio access network 20, the core network 30, and the user equipment (User Equipment, UE) 10 together constitute the entire UMTS.

Figure 2 shows the network structure diagram of UTRAN. UTRAN includes one or more radio network subsystems (Radio Network Subsystem, RNS) 22. An RNS 22 is composed of a radio network controller (Radio Network Controller, RNC) 24 and one or more NodeBs (base stations) 26. The interface between the RNC 24 and the core network 30 is the Iu interface, and the NodeB 26 and the RNC 24 are connected through the Iub interface. Within the UTRAN, the RNCs 24 are interconnected through the Iur interface, and the Iur interface can be connected through a direct physical connection or a transmission network between the RNCs 24. The RNC 24 is used to allocate and control the radio resources (Radio Resource) of the NodeB 26 connected or related to it. The NodeB 26 completes the conversion of the data flow between the Iub interface and the Uu interface, and also participates in a part of wireless resource management. NodeB 26 is the base station of the WCDMA system, including wireless transceivers and baseband processing components. It is interconnected with RNC 24 through the standard Iub interface, and mainly completes the processing of the Uu interface physical layer protocol. Its main functions are spread spectrum, modulation, channel coding and despreading, demodulation, channel decoding, and also includes functions such as mutual conversion of baseband signals and radio frequency signals. RNC 24 is used to control the radio resources of UTRAN, and mainly completes functions such as connection establishment and disconnection, handover, macro-diversity combination, and radio resource management control.

The above network architecture is based on the previous version of 3GPP Re16. At present, the 3rd Generation Partnership Project (3GPP) is studying a new evolution network architecture to meet the needs of the next ten years or even longer. Application requirements of mobile networks. Since it is a brand new network architecture, all nodes, functions, and processes of the existing architecture will undergo substantial changes. There are currently many evolution schemes being discussed in 3GPP. The purpose of network evolution is to provide a low-latency, high data rate, high system capacity and coverage, low-cost, completely IP-based network.

3GPP provides a wireless evolution network, and Long Term Evolution (LTE) is a dedicated abbreviation for the 3GPP Network Long Term Evolution project. In this evolved network, the architecture of the access network part has evolved from a two-node structure of NodeB and RNC of the 3G network to a single-node architecture with only one node eNodeB (evolved NodeB). In the research of the evolution network, the design of the radio resource management function of the radio access network is an important topic, especially considering the radio resource management (Radio Resource Management, RRM) function between eNodeBs, such as interference management, load balancing wait. The RRM functional architecture of LTE achieved for this subject is shown in Figure 3.

FIG. 3 is a distribution diagram of the functional architecture of the RRM in the prior art. In this architecture, E1 is the air interface between the UE 10 and the network side; E2 is the logical interface, actually composed of E1 and E3; E3 is the interface between the eNodeB 50 and the central node eCRNC (evolved Controlling RNC, evolution control RNC) 60 , the eCRNC 60 has the RRM function between eNodeB 50; E4 is the user plane interface between the eNodeB and the core network node; E5 is similar to the existing Iu interface, and is the interface between the access network and the core network; E6 is the MME/ASGW (Mobility Management Entity/AccessGateway, mobile management entity/access gateway) 80 and the control plane and user plane interface between the anchor point (not shown); E7 provides eNodeB and gateway module 70 (O&M Node, Operations & Maintenance Node, interface between running and maintaining nodes).

Under this architecture, the RRM function is mainly completed by the eNodeB 50, while other RRM functions such as inter-eNodeB 50 are mainly completed by the central node eCRNC 60.

When performing the RRM function between eNodeBs 50, it is necessary to obtain the RRM information of adjacent eNodeBs 50. The acquisition of RRM information in this architecture is completed through the E3 interface, that is, each eNodeB 50 provides local RRM information to the central node eCRNC, and eCRNC is responsible for The RRM information is collected, and the corresponding RRM function between eNodeB 50 is completed based on the information.

Most wireless communication systems are based on so-called multiple access techniques in which information such as voice and data is transmitted. It is a technique in which many simultaneously active users share the same system resources in an organized fashion.

In the 3G network using CDMA technology, due to the pseudo-orthogonal codes used, there is mutual interference between multiple users in a cell. Traditionally, this interference has been considered as part of the unavoidable noise that corrupts the transmission.

In an evolved network using OFDMA technology, due to the orthogonality of subcarriers between different users in the same cell, theoretically there is no inter-user interference. However, when the same frequency band is used between cells, inter-cell interference becomes a problem that affects system performance. important factor. Therefore, people need to implement interference management and load balancing between cells in the wireless evolved network, that is, it is necessary to manage radio resources in the wireless evolved network.

However, a problem is that only the architecture of the RRM system is defined in the related art, and no specific solution on how to implement interference management and load balancing under the architecture is given.

The solution of soft multiplexing of radio resources in the prior art will be described below with reference to FIG. 4 . This solution solves the interference problem at the cell edge and can also provide better spectrum utilization.

The resources between cells adopt the method of wireless resource soft multiplexing, that is, each cell is divided into two parts: the central area and the edge area. The edge area is the area where signals intersect with other cells. The edge area of each cell is statically or Some radio resources are allocated semi-statically, and the radio resources allocated to the edge areas of adjacent cells are disjoint. In the process of scheduling service transmission, the base station first schedules the UEs in the fringe area, and the scheduled radio resources can only be among the radio resources assigned to it; after the UE scheduling in the fringe area is completed, it then schedules the For the UE, its schedulable radio resources are all remaining radio resources. Part of the resource allocation at the edge of the cell can be changed in a relatively long period to ensure the optimization of resources in a long period of time. The above solution solves the interference problem at the edge of the cell, and can also provide better spectrum utilization (the wireless resource allocation scheme that divides the cell into the edge and the center is called soft multiplexing of wireless resources). The resource allocation of this scheme is shown in Figure 4.

However, this solution is limited to solving the interference problem at the edge of the cell, and it is aimed at the solution of the physical layer, but there is still no specific solution for how to implement load balancing-based radio resource management under the LTE architecture shown in Figure 3 plan.

Therefore, people need a solution that can solve the above problems in the related art, and is used for managing wireless resources in the wireless evolved network.

Contents of the invention

In view of this, the technical problem to be solved by the present invention is to provide a method and device for batch handover of terminals in a wireless evolution network, so as to realize load balancing among cells in the evolution network.

In order to solve the problems of the technologies described above, the present invention realizes by adopting the following technical solutions:

The present invention is a method for terminal batch switching in a wireless evolution network, which comprises the following steps:

Step a, the wireless support server obtains the latest radio resource management related information of the source base station cell and the target base station cell;

Step b. The wireless support server performs batch handover action decisions for wireless resource management based on the latest collected radio resource management related information between cells, and determines whether batch handover is required. When batch handover is required, proceed to step c, when the batch switching process is not required, return to step a;

Step c, the source base station, the target base station and their terminals cooperate to perform subsequent batch handover of terminals.

In this method, step a can include two situations,

In the first case, step a specifically includes the following steps:

Step a1, the source base station and its target base station respectively monitor and collect current radio resource management related information of the cell;

In step a2, the source base station and its target base station respectively report inter-cell radio resource management related information to the wireless support server through event triggering or periodic triggering.

In the second case, step a specifically includes the following steps:

Step a1', the source base station and its target base station respectively monitor and collect current radio resource management related information of the cell;

Step a2', the wireless support server requests inter-cell radio resource management related information from the source base station and its target base station through event triggering or periodic triggering;

In step a3', the source base station and the target base station respectively report inter-cell radio resource management related information to the wireless support server after receiving the request.

In this method, step c specifically includes the following steps:

Step c1, the wireless support server sends handover request signaling to the source base station;

Step c2. After receiving the handover request signaling, the source base station selects some terminals at the boundary of the target cell indicated in the signaling, and finally decides whether to perform batch handover. When batch handover is required, proceed to step c3. When batch switching is not required, return to step a;

Step c3, the source base station sends batch handover request signaling to the target base station;

Step c4, the target base station analyzes the request signaling, performs access control, context and resource reservation for the terminal, and then sends batch handover confirmation request signaling to the source base station;

Step c5, the source base station receives the batch handover confirmation request signaling, and sends a batch handover command to the corresponding terminal;

Step c6. After the corresponding terminal receives the switching command, it performs a subsequent normal switching process for each individual terminal.

In addition, the present invention also provides a device for batch handover of terminals in a wireless evolution network, which includes a wireless support server, a source base station, a target base station, and a terminal. The wireless support server triggers the batch handover process, and the source base station performs the final batch handover action. decision-making, and the source base station, target base station, and terminal jointly complete the entire batch handover process.

Compared with the prior art, the present invention has the following beneficial effects: the present invention solves the problem of wireless resource management between cells in a wireless evolution network by introducing a wireless support server to trigger a batch switching process, and realizes load balancing between cells.

Description of drawings

Fig. 1 is a system structure diagram of UMTS.

Fig. 2 is a network structure diagram of UTRAN.

FIG. 3 is a distribution diagram of the functional architecture of the RRM in the prior art.

FIG. 4 is a schematic diagram of soft frequency multiplexing of radio resources.

FIG. 5 is a wireless evolution network architecture with two layers of nodes and a wireless support server.

FIG. 6 is a signaling flow chart of terminal batch handover in the wireless evolved network according to the present invention.

Detailed ways

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and examples.

FIG. 5 shows a wireless evolution network architecture with two layers of nodes and a wireless support server.

The invention discloses a method for batch switching of terminals in a wireless evolution network. The basic idea of the invention is: a wireless support server is introduced into the evolution network, and the wireless support server collects the wireless resource management information of each base station in a periodic or event-triggered manner . The information includes load information of each cell and the like. The wireless support server makes a judgment based on the reported information. When a certain cell has a heavy load and an adjacent cell has a light load, it can trigger a batch handover process to switch some terminals in the cell to the adjacent cell, so as to To achieve the purpose of load balancing.

The method for batch handover of terminals in the wireless evolved network of the present invention will be described in detail below. As shown in Figure 6, the wireless evolution network includes a wireless support server, a source base station, a target base station and a terminal, and the method includes the following steps:

Step S1. The source base station and the target base station respectively monitor the current load of the cell. When the load in the edge area of the base station exceeds a certain threshold or is lower than a certain threshold, the source base station and the target base station report the wireless resource management information to the wireless support server respectively. information.

The information related to radio resource management includes the total load of the cell, the load of the cell edge area, the distribution of the cell edge load, or the distribution of the radio channel conditions at the cell edge in the frequency domain. The allocatable radio resource set at the edge of the cell is configured by the radio support server, so it does not need to be reported.

Step S1 belongs to the process in which the wireless support server acquires information related to radio resource management between the cells of the source base station and the target base station. The batch handover flowchart shown in FIG. 6 and the process described above are processes in which the wireless support server passively acquires the radio resource management related information of the source base station cell and the target base station cell. It should be noted that the above is only one specific embodiment of the present invention, but the present invention is not limited thereto. Step S1 of the present invention may also be a process in which the wireless support server actively acquires information related to radio resource management of the source base station cell and the target base station cell.

The following is the procedure for the wireless support server to actively acquire the radio resource management related information of the source base station cell and the target base station cell, which specifically includes:

Step S1', the source base station and the target base station respectively monitor the current load situation of the cell, and when the load in the edge area exceeds a certain threshold or is lower than a certain threshold, report the information to the wireless support server; the wireless support server receives the report After receiving the above information, the wireless support server sends an inter-cell radio resource management request to all target base stations adjacent to the source base station, requesting the target base station to provide necessary inter-cell radio resource management related information; the target base station receives the inter-cell radio resource management request Afterwards, according to the requirement in the signaling, report the corresponding radio resource management related information to the wireless support server.

The above is that the source base station and the target base station respectively monitor the current load of the cell, and when the load in the cell edge area exceeds a certain threshold or falls below a certain threshold, a synchronization process of radio resource management information between cells is triggered. The present invention is also applicable to the situation of wireless resource channels, that is, the source base station and the target base station monitor the current wireless resource channel conditions of the cell, and collect information related to wireless resource management. When the situation is lower than another preset threshold, the synchronization process of radio resource management information between cells may also be triggered. Both of these two cases belong to the way of event triggering, and the present invention is not limited thereto. Similarly, the present invention can also periodically trigger the synchronization process of radio resource management information between cells.

Step S2. The wireless support server makes a batch switching action decision for wireless resource management according to the currently collected wireless resource management related information, and judges whether batch switching is required. If batch switching is required, proceed to step S3. When the batch switching process needs to be performed, return to step S1.

In this step, the specific judgment process is performed by the wireless support server according to the internal algorithm. For example, when the load of the source base station cell is too heavy and the load of the target base station cell is light, a batch handover process can be triggered, and the target base station cell Some terminals are handed over to the source base station cell; when the load of the source base station cell is too heavy and the load of the target base station cell is also heavy, the batch handover process is not performed.

Step S3 , the wireless support server sends handover request signaling to the source base station, the signaling includes the information of the handover target cell, and also includes the amount of traffic to be handed over to the target cell suggested by the wireless support server.

Step S4: After receiving the handover request signaling, the source base station selects some terminals at the boundary of the target base station cell indicated in the signaling. The selection process needs to consider the traffic volume of handover to the target base station cell suggested by the wireless support server size, but the final decision is made by the source base station, that is, the specific parameters of this handover may not be controlled by the wireless support server.

In this step, when selecting a terminal to be handed over, on the one hand, it is necessary to consider the traffic information of the terminal, and on the other hand, it is necessary to select a terminal with a better signal of its target base station according to its measurement report. The trigger threshold of the process is related, and a certain mechanism is used to prevent the terminal from switching back after being switched.

Step S5, the source base station sends batch handover request signaling to the base station cell of the target cell, and the signaling includes a list of terminals to be handed over.

Step S6, the target base station cell analyzes the request signaling, performs access control, context and resource reservation for the terminal, and then sends batch handover request confirmation signaling to the source base station.

In step S7, the source base station multicasts the handover command to corresponding terminals after receiving the batch handover request confirmation signaling.

Step S8. After receiving the switching command, the corresponding terminal performs subsequent normal switching procedures for each individual terminal.

Steps S3 to S8 belong to a specific execution process in which the wireless support server, the source base station and its target base station cooperate to execute subsequent terminal batch handovers.

In addition, the present invention also provides a device for batch handover of terminals in a wireless evolution network, which includes a wireless support server, a source base station, a target base station, and a terminal. The wireless support server triggers the batch handover process, and the source base station performs the final batch handover action. decision-making, and the source base station, target base station, and terminal jointly complete the entire batch handover process.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (11)

1. A method for terminal batch handover in a wireless evolution network, wherein the wireless evolution network includes a wireless support server, a source base station, a target base station and a terminal, wherein the method comprises the following steps: Step a, the wireless support server obtains the latest radio resource management related information of the source base station cell and the target base station cell; Step b. The wireless support server performs batch handover action decision-making for wireless resource management according to the latest radio resource management related information currently collected between cells, and judges whether batch handover is required. When a batch handover process is required, proceed to step c, when the batch switching process is not required, return to step a; Step c, the source base station, the target base station and their terminals cooperate to perform subsequent batch handover of terminals. 2. The method according to claim 1, characterized in that step a specifically comprises the following steps: Step a1, the source base station and the target base station respectively monitor and collect current radio resource management related information of the cell; In step a2, the source base station and the target base station respectively report inter-cell radio resource management related information to the wireless support server through event triggering or periodic triggering. 3. The method according to claim 1, characterized in that step a specifically comprises the following steps: Step a1', the source base station and the target base station respectively monitor and collect the current radio resource management related information of the cell; Step a2', the wireless support server requests inter-cell radio resource management related information from the source base station and the target base station through event triggering or periodic triggering; In step a3', after receiving the request, the source base station and the target base station respectively report inter-cell radio resource management related information to the wireless support server. 4. The method according to claim 2 or 3, wherein the event trigger refers to a trigger when the collected information related to radio resource management meets the terminal batch handover condition. 5. The method according to claim 4, wherein the conditions for triggering the event include: When the load of the edge area of the cell of the source base station exceeds or falls below a predetermined threshold; or When the channel condition of the schedulable radio resources originally allocated to the cell edge of the source base station becomes worse than another preset threshold. 6. The method according to any one of claims 1 to 3, wherein the radio resource management related information includes the total load of the cell, the load of the cell edge area, the distribution of the cell edge load, or the load of the cell edge. The distribution of wireless channel conditions in the frequency domain. 7. The method according to any one of claims 1 to 3, characterized in that step c specifically comprises the following steps: Step c1, the wireless support server sends handover request signaling to the source base station; Step c2. After receiving the handover request signaling, the source base station selects some terminals at the boundary of the target cell indicated in the signaling, and finally decides whether to perform batch handover. When batch handover is required, proceed to step c3. When batch switching is not required, return to step a; Step c3, the source base station sends batch handover request signaling to the target base station; Step c4, the target base station analyzes the request signaling, performs access control, context and resource reservation for the terminal, and then sends batch handover confirmation request signaling to the source base station; Step c5, the source base station receives the batch handover confirmation request signaling, and sends a batch handover command to the corresponding terminal; Step c6. After the corresponding terminal receives the switching command, it performs a subsequent normal switching process for each individual terminal. 8. The method according to claim 7, characterized in that in step c1, the handover request signaling includes the information of the handover target cell and the amount of traffic to be handed over to the target cell suggested by the wireless support server. 9. The method according to claim 7, wherein the selection of the terminal to be handed over in step c2 needs to consider the traffic information of the terminal, the terminal with a better signal of the target base station, and the trigger threshold of the normal handover process. 10. The method according to claim 1, characterized in that in step c3, the batch handover request signaling includes a list of terminals to be handed over. 11. A device for batch handover of terminals in a wireless evolution network, which includes a wireless support server, a source base station, a target base station, and a terminal, characterized in that: the wireless support server triggers the batch handover process, and the source base station performs the final batch handover action decision-making, and the source base station, target base station, and terminal jointly complete the entire batch handover process.

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