KR20040060434A - method for softly hand-over of the mobile communication system - Google Patents

Abstract

PURPOSE: A soft handover method of a mobile communication system is provided to lower the data search load of a UE(User Equipment) as the UE searches for only a specific portion of inter-RNC(Radio Network Controller) neighbor information, received from an RNC, without the necessity of executing full searching for the inter-RNC neighbor information. CONSTITUTION: In an initial state(S1), an RNC configures a neighbor cell information and transmits it to a UE(S2). The UE first searches for a specific item information among the received neighbor cell information(S3). Then the UE judges whether the contents of the presently measured specific item information(P) are larger than the contents of the specific item information(M) among the received neighbor cell information(S4). In case that M is larger than P, the UE sends an associated response message to inform the RNC that a handover is required, without searching the other neighbor cell information(S6). The RNC updates an associated DB using the received response message(S7).

Description

Method for softly hand-over of the mobile communication system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft handover method of a mobile communication system. In particular, a soft hand of a mobile communication system including a T-cell information in a neighbor cell message information and including information for determining a neighbor cell condition are also transmitted. It's about the over method.

In general, a mobile communication system processes a call by assigning a call channel to a mobile communication terminal existing in its sector, wherein the mobile communication terminal is moved away from the base station to which the mobile communication terminal is assigned during the call. Frequently, the jurisdiction moves to a cell or another sector. Accordingly, the adjacent base station performs a function of allocating a new channel instead of the radio frequency channel in use so that the call can be maintained, that is, handover or handoff function.

Then, referring to FIG. 1, the conventional DS_MAP type IMT-2000 system is connected to a plurality of base stations 70A-N, manages base stations, and outputs the processed transmission data in the form of IPOA TCP / IP. RNC 71A-N (Ridio network controller), and the core network 72 for receiving and processing data of the RNC (71A-N) by a process generated in connection with the RNC 71A-N in the form of NE .

Here, a plurality of cells 73 partitioned into a predetermined area are formed in the plurality of base stations 70A-N.

On the other hand, looking at the handover method of the conventional mobile communication system as described above, first to determine the handover (handover) of the terminal 74 existing in a predetermined position (RNC for jurisdiction over the area where the terminal 74 is located) The information elements (eg, neighbor list, reporting range, hysteresis, ...) required for handover determination under the control of the core network 72 at 70N are SIB11 / 12 (System information block 11) of the system information which is an RRC message. / 12) and a measurement control message to the corresponding terminal 74. Then, the terminal 74 measures the cell to which the call is set and the neighbor cell, and the cell satisfying the handover condition among the cells, that is, the cell satisfying the event add criteria, is measured through a measurement report. Notify the RNC 71N. In this case, the terminal 74 performs full search on the inter-RNC neighbor information received from the RNC 71N through a radio link setup response / radio link addition response message as shown in FIG. 2. To the corresponding RNC 71N. The RNC 71N determines whether the current terminal 74 should be handed over with reference to the measurement report message received from the terminal 74 and executes handover through the core network. In this case, when a soft handover occurs in the other RNC, information of another RNC and a terminal is updated through neighbor cell information.

However, in the handover method of the conventional mobile communication system as described above, since the inter-RNC neighbor information provided to the terminal by the RNC does not include specific cell information to determine the handover, it is difficult for the terminal to optimize the wireless network. In addition, since the terminal needs to search the Inter-RNC neighbor information provided by the RNC to provide information for handover, there is a problem in that the processing load of the terminal becomes heavy accordingly.

Accordingly, the present invention has been invented to solve the above-mentioned conventional problems, and since the terminal does not need to retrieve all of the Inter-RNC neighbor information received from the RNC, the mobile terminal can significantly reduce the data retrieval load accordingly. It is an object of the present invention to provide a soft handover method of a communication system.

Another object of the present invention is that the terminal searches for and processes only a specific part of the Inter-RNC neighbor information received from the RNC, so that the handover of the terminal significantly improves the speed of handover. To provide an over method.

The present invention for achieving the above object is an RNC message transmission step of the RNC of the mobile communication system to configure the neighbor cell information containing the specific cell information and transmitting to the corresponding terminal, and received by the terminal after the RNC message transmission step The NAVER cell information processing step of searching for specific item information among NAVER cell information first, and the content of specific item information among the NAVER cell information received by the content P of the specific item information currently measured after the NAVER cell information processing step (M). The specific cell information checking step of checking whether the value has a larger value than) and the content P of the specific item information currently measured during the specific cell information checking step do not have a value larger than the content M of the received specific item information. If it is confirmed, it is not a handover state. Therefore, the terminal searches for all remaining NAVER cell information other than the specific item information and sends the necessary response message to the RNC. If it is confirmed that the content (P) of the specific item information currently measured during the corresponding response message transmission step and the specific cell information checking step has a larger value than the content (M) of the received specific item information, this is necessary. The present invention provides a soft handover method of a mobile communication system comprising a handover decision information transmitting step of transmitting a related response message indicating a state requiring handover to the RNC without retrieving the remaining neighbor cell information.

1 is an explanatory diagram illustrating a structure of a conventional mobile communication system.

2 is an explanatory diagram showing neighbor cell information in the system of FIG. 1;

3 is an explanatory diagram illustrating a mobile communication system to which the present invention is applied.

4 is an explanatory diagram for explaining NAVER cell information including a specific cell applied to the present invention.

5 is a flowchart of the present invention.

<Detailed Description of Codes>

1: cell 2: terminal

3A-N: Base Station 4A-N: RNC

5: core network

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The apparatus to which the present invention is applied processes the signals of the terminal 2 and processes the handover measurement report signal through a plurality of cells 1 partitioned into a predetermined radio wave transmission / reception area based on the installed position as shown in FIG. 3. Transmits neighbor cell information including T-CELL (strength value of radio wave of neighbor cell) to a plurality of base stations 3A-N and the plurality of base stations 3A-N Receive processing of the data of the RNC (4A-N) by the RNC (4A-N) to determine the handover of the terminal 2 and the process generated by being connected to the RNC (4A-N) in the form of NE It consists of the core network (5).

Herein, the items included in the neighbor cell information include neighboring UMTS cell information, cell-ID, primary scrambling code, primary CPICH power, cell individual offset, reporting range, hysteresis, Tx Diversity indicator, and T- as shown in FIG. Cell parameters are included.

Next, the method of the present invention as described above will be described.

The method of the present invention proceeds to the RNC message transmission step (S2) in the initial state (S1), as shown in Figure 5, the RNC configures the neighbor cell information and transmits to the terminal. After the RNC message transmission step, the mobile station proceeds to the neighbor cell information processing step S3 to search for specific item information among neighbor cell information received by the terminal. After the NAVER cell information processing step (S3), the process proceeds to a specific cell information determining step (S4), where the content P of the specific item information currently measured is higher than the content M of the specific item information received from the NAVER cell information. Determine if it has a large value. In this case, when the content P of the specific item information currently measured does not have a value larger than the content M of the specific item information in the received neighbor cell information as a result of the determination in the specific cell information determining step S4. Since the process proceeds to the normal response message transmission step (S5), the terminal searches for all remaining NAVER cell information other than the specific item information, and sends out the necessary response message to the RNC.

However, if the content P of the specific item information currently measured has a larger value than the content M of the specific item information in the received neighbor cell information, the handover is required. Since it is a state, the process proceeds to the handover decision information sending step (S6), and the terminal sends a related response message to the RNC informing the state that the handover is necessary without retrieving the remaining neighbor cell information. After the sending of the handover decision information (S6), the process proceeds to the related DB update step (S7) to update the DBs of the related devices by using the response message received from the terminal.

In other words, first, under the control of the core network 5 in the RNC 4A, which governs the area where the terminal 2 is located, in order to determine whether the terminal 2 existing in a certain position is handed over. 4, that is, neighboring UMTS cell information, cell-ID, primary scrambling code, primary CPICH power, cell individual offset, reporting range, hysteresis, Tx Diversity indicator and T-Cell The information including the parameter of is transmitted to the corresponding terminal 2 via the base station 3A.

Then, the terminal 2 does not search all the contents of the neighbor cell information received from the RNC 4A, but only the specific item information, for example, the contents of the T-CELL. At this time, the terminal 2 is the content (P) of the specific item information currently measured, that is, the content (M) of the specific item information among the neighbor cell information received by the radio wave strength of the neighbor cell, that is, the radio wave strength of the cell currently being received. Determine if it has a larger value. At this time, the terminal 2 is not a handover state if the content (P) of the currently measured T-CELL does not have a larger value than the T-CELL (M) received. All remaining NAVER cell information is retrieved and necessary response messages are sent to the RNC 4A via the base station 3A.

However, the terminal 2 when the radio wave strength value (P) of the neighboring cell currently measured has a value larger than the value (M) of the T-CELL among the received neighbor cell information, this is a state in which handover is necessary, and thus the remaining neighbor cells The RNC sends an associated response message to the RNC 4A indicating that a handover is necessary without retrieving the information.

Therefore, since the terminal 2 receives and processes only specific cell information without having to search all the contents of the neighbor cell information received from the RNC 4A, the processing load is considerably reduced compared to the conventional apparatus.

Meanwhile, the corresponding RNC 4A determines whether the current terminal 2 should be handed over with reference to the measurement report message transmitted from the terminal 2 and executes the handover through the core network 5. In this case, when a soft handover occurs to the other RNC, information of another RNC 4N and the terminal is updated through neighbor cell information.

As described above, the present invention includes all the Inter-RNC neighbor information received from the RNC by transmitting the information including the information of the T-cell in the neighbor cell message information to determine the neighbor cell condition. Since there is no need to search, the data search load of the terminal can be considerably reduced.

In addition, according to the present invention, since the terminal searches for and processes only a specific part in the Inter-RNC neighbor information received from the RNC, there is an effect of significantly improving the handover of the terminal.

Claims (1)

In the handover method of the mobile communication system to guarantee the inter-cell handover of the terminal, Receiving information that is a reference for the handover including the information on the location of the pilot signal of the neighbor cell, and performing the handover if the reference information is satisfied. Soft handover of the system.