CN101009921A - A cross-area switching method of the mobile terminal device - Google Patents

Abstract

The present invention provides a handover method of a mobile terminal equipment, comprising the following steps: the mobile terminal equipment provides a plurality of possible handover target cells of different target systems, and provides the first data to the source system; the source system further Determining multiple possible handover target cells of the target system, and providing second data containing at least one target cell identifier to each target system, indicating the target cell; each target system checks whether the identified target cell can become a required The target cell for handover, and the result is fed back to the source system as the third data, indicating the selected target cell; the mobile terminal device executes the target cell from the source system to the selected target system according to the decision of the source system. Cell handover. The invention combines the source system and the target system in the wireless communication system to select the target cell to complete the handover, thereby increasing the reliability of the handover process.

Description

A handover method for mobile terminal equipment

【Technical field】

The invention relates to a wireless cellular communication device, in particular to a method for handover of a mobile terminal device.

【Background technique】

Currently, in existing wireless cellular communication systems, such as GSM, UMTS..., the act of transmitting communication information of a communication terminal from one base station to another base station is called handover. In cellular radio communication systems, such as the 802.16E standard, different handover procedures are specified.

US Patent No. 6,466,556 presents a handover method which aims to cause little interruption of packet flow during the handover process. In addition to performing handover procedures within a given cellular radio communication system, these procedures may also be implemented in handoffs between systems. However, when using this method, the handover sometimes fails, causing the communication connection to be interrupted.

Accordingly, the present invention seeks to provide an improved method of performing a handover procedure, and a controller in a wireless cellular communication system.

【Content of invention】

The object of the present invention is to provide a method for performing handover for mobile terminal equipment.

The purpose of the present invention is achieved through the following technical solutions: a handover method of a mobile terminal equipment, which is applied to the handover of a mobile terminal equipment from a wireless cellular communication source system to a wireless cellular communication target system, the method comprising The following steps:

The mobile terminal equipment provides a plurality of possible handover target cells of different target systems, and provides the first data to the source system;

The source system further determines a plurality of possible handover target cells of the target system, and provides each target system with second data containing at least one target cell identifier, indicating the target cell;

Each target system checks whether the identified target cell can become a target cell requiring handover, and feeds the result back to the source system as third data to indicate the selected target cell;

The mobile terminal equipment performs a handover from the source system to the selected target cell of the target system in accordance with the determined handover request of the source system.

Wherein, when the target system of the identified possible handover target cell is already operating at full capacity, the target system rejects the handover request.

Wherein, when the target system of the identified possible handover target cell has idle capacity, the target system accepts the handover request.

Wherein, when there are multiple target systems capable of accepting the handover request, the source system may select a target cell from among them for handover.

Wherein, the selection of the source system may be random.

Among other things, the selection of source systems may be based on additional quality criteria.

Wherein, the criterion for the source system to select the handover is the load condition of the target cell informed by the target system to the source system, or the load balance criterion.

Wherein, the source system may select multiple possible handover target cells based on the network topology structure of each target system.

Wherein, the first data includes radio link measurement information of multiple possible handover target cells.

Wherein, the second data includes capability information of the mobile terminal equipment, current service connection information, and indicates at least one possible handover target cell in the target system.

Compared with the prior art, the present invention has the following advantages: the present invention does not select the target cell only by the source system or the target system to complete the handover, but selects the target cell by the combination of the source system and the target system. The handover is performed, which increases the reliability of the handover procedure. And in this way, firstly, the impact of the network topology on the handover time is taken as one of the considerations; secondly, the source system initially selects the target cell and can select the qualified cell as much as possible, reasonably narrowing down the scope of the target cell, To reduce the burden of handover and link establishment; again, the target system can further select the target cell by taking into account the impact of the cell's available capacity and load balance.

【Description of drawings】

Figure 1 is a block diagram of a source system and a target system.

2 is a block diagram of a wireless cellular communication system.

【Detailed ways】

The invention combines the source system and the target system in the wireless communication system to select the target cell to complete the handover, thereby increasing the reliability of the handover process. In order to perform handover, the mobile terminal device determines a plurality of possible handover target cells of the target system, and notifies the source system of these target cells, and the source system further identifies a plurality of possible handover target cells of the target system, The target system is notified of these possible handover target cells, and the target system selects one target cell from multiple possible handover target cells, and notifies the source system of the selection result. In response, the source system initiates a handover procedure for the mobile terminal device.

Please refer to FIG. 1 , which is a block diagram of a source system and a target system of a wireless communication system. In this case, the mobile terminal 10 can identify a possible handover target cell. The wireless cellular communication system includes a wireless cellular communication source system 20 and a target system 30. The source system 20 and the target system 30 perform a handover process of a mobile terminal device from the source system to the target system, wherein the source system 20 includes a mobile terminal for receiving A radio resource agent 24 for equipment forwarding information, and a radio resource controller 22, the radio resource controller 22 includes an air interface device for receiving first data from the mobile terminal equipment, and further determines on the basis of the above-mentioned first data A possible or better handover target device, a device for sending second data to the target system, a device for receiving third data indicating a target cell selected by the target system, and performing mobile terminal equipment from the source system to the selected A device for handover of a target cell of a target system. The target system 30 includes a radio resource agent 34 for receiving the forwarding information of the mobile terminal equipment, and a radio resource controller 32, the radio resource controller 32 includes means for receiving second data from the source system, selecting a target cell A device, a device that provides the third data to the source system.

In order to identify adjacent cells that can provide optional coverage for the mobile terminal device 10, the mobile terminal device 10 periodically scans one or more frequency bands to identify possible handover target cells and form a group of possible handover targets The cell identification list, and simultaneously obtain the measured values of the radio link parameters of these target cells, such as the signal-to-noise ratio, delay and other radio link parameter measurement values, and generate the first data according to the cell identification list and the obtained radio link parameters.

The mobile terminal device 10 can notify the radio resource controller 22 of the source system 20 of these possible handover target cells. This can be accomplished through the following process: the mobile terminal device 10 forwards the first data to the radio resource agent 24 of the source system 20, wherein the first data contains a set of possible handover target cell identification lists, and the radio frequency of each target cell. Link parameter measurement information. The radio resource controller 22 of the source system 20 selects some possible or better target cells from the list of target cell identifiers in the first data received by the radio resource agent 24, and combines the capability information of the mobile terminal device, the current service connection information to generate second data, and then the radio resource controller 22 forwards the second data to the radio resource controller 32 of the target system 30 . The radio resource controller 32 then selects a target cell that is most suitable for providing a communication link that requires handover from the target cell identification list that has been screened in the second data, and generates third data. Then, the radio resource controller 32 The third data including the final handover target cell is notified to the RRC 22 of the source system 20 through signaling. In response, the radio resource controller 22 initiates handover procedure operations to the selected target cell.

According to another preferred embodiment of the present invention, it is used in multiple target systems. When the number of possible handover target cells determined by the mobile terminal device 10 exceeds a certain limit, if the radio resource controller 22 of the source system 20 forwards the first data to all target cells, the handover time will be increased, And it is not necessary to forward the first data to all target cells. In this case, the source system 20 can use the acquired prior knowledge of the target cell, such as the topology information of each system controller, the physical layer capability and MAC layer capability of the mobile terminal device, or the mobile terminal device report Some of the radio link parameter measurement values, preliminarily determine some better target cells, and remove other target cells from the cell identification list, so as to reduce the burden of system handover.

According to another preferred embodiment of the present invention, it is also used in multiple target systems. In multiple target systems, when the possible handover target cells determined by the mobile terminal device 10 belong to different target systems, the mobile terminal device 10 provides the first data to the source system, and the radio resource controller 22 of the source system 20 further determines the target cell A plurality of possible handover target cells of the system, and providing each target cell with second data containing at least one target cell identity. Each target system then checks whether the identified possible handover target cell can currently become the serving cell of the communication link requiring handover, and feeds back the result as the third data back to the source system, and the mobile terminal equipment according to the source system's A handover request is determined to perform a handover from the source system to the selected target cell of the target system.

If the target system for an identified potential handover target cell is already operating at full capacity, the target system rejects the handover request. And when the target system of another identified possible handover target cell still has spare capacity, the target system will accept the handover request. In this case, the RRC 22 of the source system 20 initiates a handover procedure to the target cell of the target system which has spare capacity. In this way, a situation is avoided in which a handover to a target cell is initiated, which may fail, possibly resulting in an interruption of the communication link requiring the handover.

The RRC 22 of the source system 20 can choose if more than one target system sends a response that can accept the handover request. This selection may be random, or based on additional quality criteria, for example, the target system notifies the source system 20 of the radio resource controller 22 of the target cell load, or load balancing criteria, and then the source system 20 radio resource The controller 22 determines the handover request according to the reported situation.

According to another preferred embodiment of the invention, the source system 20 and the target system 30 have different air interfaces. In order to perform an intersystem handover, a dual-mode or multi-mode mobile terminal device 10 supporting different air interfaces is required. When working in the source system 20, the mobile terminal device 10 uses another air interface of the target system 30 to identify possible handover target cells in the target system 30 by scanning the frequency spectrum. Alternatively, the source system 20 may also initiate an inter-system handover by itself under the condition of considering load balance.

Generally, the target system 30 further selects a target cell from the list of possible handover target cells provided by the source system 20. The advantage of this is that since the target system 30 has the latest information on the status of its cells, it can choose a cell wisely. Possible handover target cells.

The technical solution of the present invention will be described in detail below in conjunction with a specific wireless communication system.

Figure 2 is a block diagram illustrating a wireless cellular communication system, such as a UMTS type system. The communication system has multiple wireless network base station controllers interconnected by a packet-switched wired backbone. Each base station controller controls a plurality of base transceiver stations BTS to cover the cell, for example, the base station controller 220 controls the cell base transceiver station BTSi 240, wherein, the value of i ranges from 1 to 256. Similarly, the base station controller 320 controls the base transceiver station BTSj 340 of the cell, where the value of j ranges from 1 to 256.

The mobile terminal device 100 periodically scans one or more frequency bands, identifies possible handover target cells, forms a group of possible handover target cell identification lists, and obtains the measured values of radio link parameters of these target cells at the same time , such as measured values of radio link parameters such as signal-to-noise ratio and delay, generating first data according to the cell identity list and the acquired radio link parameters.

The mobile terminal device 100 forwards the first data of these possible handover target cells to the base transceiver station BTSi 240 of the source system 200. The base station controller 220 selects some possible or better target cells from the target cell identification list in the first data received by the base transceiver station BTSi 240, and generates the second target cell in combination with the capability information and current service connection information of the mobile terminal equipment. second data, and then the base station controller 220 forwards the second data to the base station controller 320 of the target system 300 . The base station controller 320 then selects a target cell that is most suitable for providing a communication link requiring handover from the target cell identification list that has been screened in the second data, and generates third data, and then the base station controller 320 will include The third data of the final handover target cell is notified to the base station controller 220 of the source system 200 through signaling. In response, base station controller 220 initiates handover procedure operations to the selected target cell.

The above are only the best examples 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 should be included in the protection scope of the present invention within.

Claims (10)

1, a kind of method of handover of mobile terminal device is applied to carry out the handover of mobile terminal device from the radio honeycomb communication origin system to the radio honeycomb communication goal systems, and this method may further comprise the steps:

Mobile terminal device provides a plurality of possible handoff target sub-district of different target system, and provides first data to origin system;

Origin system is further determined a plurality of possible handoff target sub-district of goal systems, and provides second data that contain at least one Target Cell Identifier, indicating target sub-district to each goal systems;

Each goal systems checks respectively whether the Target cell that is identified can become the Target cell that needs handover, and the result is fed back to origin system as the 3rd data, the Target cell that indication is selected;

Mobile terminal device is carried out the handover of the Target cell from origin system to the goal systems of selecting according to the decision hand-off request of origin system.

2, the method for handover of mobile terminal device as claimed in claim 1, wherein, during the goal systems oepration at full load of the possible handoff target sub-district that is identified, described goal systems refusal hand-off request.

3, the method for handover of mobile terminal device as claimed in claim 1, wherein, when the goal systems of the possible handoff target sub-district that is identified had idle capacity, described goal systems was accepted hand-off request.

4, the method for handover of mobile terminal device as claimed in claim 1, wherein, when having a plurality of goal systems to accept hand-off request, origin system can therefrom carry out the select target sub-district and carry out handover.

5, the method for handover of mobile terminal device as claimed in claim 4, wherein, the selection of origin system can be at random.

6, the method for handover of mobile terminal device as claimed in claim 4, wherein, the selection of origin system can be based on additional quality standard.

7, the method for handover of mobile terminal device as claimed in claim 6, wherein, it is the Target cell loading condition that goal systems is informed origin system that origin system is selected the standard of handover, or the load balance standard.

8, the method for handover of mobile terminal device as claimed in claim 2, wherein, origin system can be selected a plurality of possible handoff target sub-districts based on the network topology structure of each goal systems.

9, the method for handover of mobile terminal device as claimed in claim 1, wherein, first data comprise the Radio Link metrical information of a plurality of possible handoff target sub-districts.

10, the method for handover of mobile terminal device as claimed in claim 1, wherein, second data comprise at least one possible handoff target sub-district in ability information, current business link information and the indicating target system of mobile terminal device.

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