KR20090080840A - Asynchronous Mobile Communication System for performing interfrequency hard handover using beacon signal and method thereof - Google Patents

Abstract

An asynchronous mobile communication system for performing the hard handover between different frequencies by using a beacon signal and a method thereof are provided to minimize the lowering of quality by not using a compressing mode, thereby reducing the consumption of radio resources. A method for performing the hard handover to a target base station(300) using the second frequency from a serving base station(200) using the first frequency in an asynchronous network comprises the following steps of: transmitting a beacon signal which includes information about the target base station to a mobile station(100) by using the first frequency; receiving a measurement report about the first frequency which includes information about the target base station; and performing the hard handover based on the measurement report in case the preference cell of the mobile station is a border cell in which the serving cell and target cell intersect.

Description

Asynchronous mobile communication system for performing interfrequency hard handover using beacon signal and method

The present invention relates to an asynchronous mobile communication system and method for performing hard handover between different frequencies using a beacon signal. More particularly, the present invention relates to a mobile communication system and a method for performing hard handover between frequencies in an asynchronous mobile communication network in which at least two cells having different frequency channels overlap each other.

For transmitting and receiving data, a mobile communication service provider receives a predetermined frequency band, and divides the allocated frequency band into a plurality of frequency bands for operating various mobile communication systems and accommodating a plurality of subscriber stations. Here, the subdivided frequency band is called (Frequency Assignment, hereinafter referred to as 'FA').

In general, in a mobile communication network in which at least two or more cells having different frequency channels are overlapped with each other, inter frequency assignment hard handover frequently occurs.

However, in the case of inter-frequency hard handover between neighboring base stations, when the mobile station executes using one receiver, a frequency switching process of converting a current frequency into a corresponding frequency is required in order to measure another frequency being used by the neighboring base station.

In this frequency switching process, transmission of data such as a voice packet is interrupted, so the mobile station implements a compressed mode for compressing and transmitting data in order to prevent communication quality degradation.

Conventionally, in an asynchronous mobile communication network, for example, wideband code division multiple access (W-CDMA), a compression mode method is used to perform hard handover between frequencies. . W-CDMA is a third generation mobile communication scheme ^{disclosed in} 3rd Generation Partnership Project (3GPP).

The 3GPP standard defines inter FA hard handover under the assumption that the UE performs measurement on other frequencies by the compression mode operation.

That is, a mobile station that satisfies the 3GPP Frequency Division Duplex (hereinafter referred to as 'FDD') standard sets a compression mode, compresses data to be transmitted during one frame, and transmits data in a short time. Secure the time to measure the frequency, or transmission gap.

In this case, in order to blank the time slots corresponding to the transmission gap length, the transmission interval corresponding to the transmission gap length should be reduced. In other words, all data to be transmitted must be transmitted in the transmission section that is shorter than the original transmission section, that is, reduced by the time slots corresponding to the transmission gap length.

Therefore, a method of reducing a spreading factor (hereinafter, referred to as 'SF') is used as a method for reducing a transmission interval. In other words, the data is compressed and transmitted through the transmission interval reduced to 1/2 by reducing to 1/2 of the diffusion rate in the normal mode, and the rest is used as the transmission gap.

As a result, since the radio resources, for example, the hardware resources of the base station channel card are instantaneously used, the radio resources are consumed a lot.

In addition, it is necessary to measure its own frequency while measuring other frequencies during the transmission gap, so that the frequency change is severely generated, resulting in a large load of the terminal, which may result in deterioration of quality due to the performance degradation of the terminal.

Accordingly, an aspect of the present invention is to provide a method for performing an intra-frequency hard handover of an intra measurement type without operating in a compression mode using a beacon signal in an asynchronous mobile communication network, and a system and a terminal device for implementing the same.

In order to achieve the problems described above, the asynchronous mobile communication system according to the characteristics of the present invention,

In an asynchronous mobile communication system performing a hard handover between frequencies from a serving base station using a first frequency to a target base station using a second frequency, a beacon signal including information about the target base station is configured to receive the first frequency. A beacon transmitter that transmits to a mobile station using; And receiving a measurement report for the first frequency including information about the target base station from the mobile station, and when the preferred cell of the mobile station is a border cell where the serving cell of the mobile station and the target cell intersect, based on the measurement report. And a radio network controller for performing a hard handover between frequencies of the mobile station from the first frequency to the second frequency.

Inter-frequency hard handover method according to a feature of the present invention,

A method for performing frequency-to-frequency hard handover from a serving base station using a first frequency to a target base station using a second frequency in an asynchronous mobile communication network, the method comprising: transmitting a beacon signal including information about the target base station to the first frequency; Transmitting to the mobile station using; Receiving a measurement report for the first frequency from the mobile station that includes information about the target base station; And performing a hard handover between the frequencies of the mobile station from the first frequency to the second frequency based on the measurement report when the preferred cell of the mobile station is a border cell where the serving cell of the mobile station and the target cell intersect. do.

According to the present invention, it is possible to minimize the deterioration of quality by not using the compression mode, thereby reducing the consumption of radio resources and to implement stable handover.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, terms such as “… unit”, “… module” described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software.

In this specification, a mobile station (MS) includes a terminal, a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), and a user equipment. It may also refer to a user equipment (UE), an access terminal (AT), and the like, and may include all or some functions of a terminal, a mobile terminal, a subscriber station, a portable subscriber station, a user device, an access terminal, and the like.

In the present specification, a base station (BS) includes an access point (AP), a radio access station (RAS), a node B (Node-B), and an eNB (Evolved Node-B) transmitting and receiving base station (Base) It may refer to a Transceiver Station (BTS), a Mobile Multihop Relay (MMR) -BS, or the like, and may include all or a part of functions such as an access point, a radio access station, a Node B, an eNB, a transceiver base station, and an MMR-BS. have.

Now, an asynchronous mobile communication system and method for performing hard handover between different frequencies using beacon signals according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram illustrating a configuration of a cell performing frequency hard handover in a border cell of an asynchronous mobile communication network according to an embodiment of the present invention.

As shown in FIG. 1, the conceptual diagram is implemented in an asynchronous mobile communication system performing hard handover between frequencies from a serving base station using a first frequency to a target base station using a second frequency.

That is, the range 500 of the serving base station (Node B) 200 and the serving base station (Node B) 200, the range of the target base station (Node B) 300 and the target base station (Node B) 300 ( 600 and border cell 700.

In this case, the serving base station (Node B) 200 and the target base station (Node B) 300 uses one or more different frequencies FA.

The serving base station (Node B) 200 and the target base station (Node B) 300 are base stations for transmitting an asynchronous mobile communication signal, and the mobile station uses frequencies FAs allocated within the respective ranges 500 and 600. It is connected to the wireless section 100 and controls the mobile station 100 and connects the call channel.

A radio network controller (RNC) is a system for controlling a plurality of base stations (Node B), that is, a serving base station (Node B) 200 and a target base station (Node B) 300, MSC which is a core equipment (Mobile Switching Center) / VLR (Visitor Location Register), SGSN (Serving Gateway Service Node).

The border cell 700 refers to an area where handover actually occurs. The border cell 700 may refer to an area hatched by a cell of a portion where cells of a range using different frequencies FA overlap.

The mobile station 100 moves from the area of the serving base station (Node B) 200 to the area of the target base station (Node B) 300 by performing an inter frequency assignment hard handover in the border cell 700. Even without interruption, communication is possible.

In this case, in the conventional asynchronous mobile communication network, for example, in a wideband code division multiple access (W-CDMA) network, frequency measurement for hard handover between inter frequencies is performed using a compressed mode. In general, in the embodiment of the present invention, a hard cell-over between frequencies is performed in a border cell by using a beacon signal.

FIG. 2 is a conceptual diagram for performing hard handover between frequencies in a border cell of an asynchronous mobile communication network according to an embodiment of the present invention, which will be described using an W-CDMA network as an embodiment.

As shown in FIG. 2, one sector of FA for each base station Node B is divided into subcells as a unit service area, and the subcells are divided into normal cells and border cells. That is, for 1FA and 2FA held by the serving base station Node B, a sector of 2FA not held by the target base station Node B adjacent to the serving base station Node B is set as a border cell, and the other FA sectors are normal. Set to cell.

Here, the conceptual diagram shown in FIG. 2 includes a target base station region 800 for transmitting 1FA and 2FA signals, a border cell region 900 for including border cells, and a beacon cell for transmitting beacon signals, and a target for transmitting 1FA signals. The base station area 1000 is shown.

In the area of the base station having such a concept, the hard handover between frequencies is performed as follows.

When the mobile station 100 enters the border cell area 900, the mobile station 100 adds a border cell to the radio network controller and reports the measurement (P101). At this time, the mobile station 100 receives the neighbor base station list of the border cell and the serving cell and reports the measurement.

When the mobile station 100 continuously moves and enters the beacon cell, the mobile station 100 receives the beacon signal to give the wireless network controller a measurement report (P103) in which power of the beacon cell is added. The handover is performed to the target base station area 1000 according to the handover decision of the radio network controller.

At this time, 1a is used as the handover event type of the measurement reports P101 and P103. Event 1a triggers an intra frequency measurement as one of the handover conditions.

As such, the mobile station 100 acquires information of the target base station region 1000 using the beacon signal without using the compression mode, and reports the information necessary for determining the hard handover between frequencies to the radio network controller.

Here, the beacon uses intra FA measurement by transmitting a first common pilot channel (PCPICH) of the target FA (ie, 1FA) to a serving FA, that is, 2FA. To perform handover. The beacon masks the PCPICH of the target FA 1FA to a target primary scrambling code (hereinafter referred to as 'PSC') and converts the PCPICH into a serving FA (2FA).

In this case, when only PCPICH is transmitted, since a lot of loads are generated in the mobile station 100 to measure the strength of the corresponding PSC, the PCPICH, a primary sync channel (hereinafter referred to as 'PSCH'), By simultaneously broadcasting a second sync channel (hereinafter referred to as 'SSCH'), the mobile station 100 can easily measure the quality of the target PSC.

In a W-CDMA system, each cell is distinguished through 512 PSCs. That is, some of the PSC codes are reserved for beacon cells and a beacon cell base station is installed outside the border cell. The beacon cell transmits only the beacon signal to the mobile station without allocating resources for actual call connection, and the mobile station receives the beacon signal to recognize that the cell is a border area for handover.

That is, the target signal of 1FA is converted to 2FA and down to the serving cell. In this case, the border cell indicator for setting the edge is set to implement this function only in the border cell.

In addition, by defining a border neighbor list (Border Neighbor List) to insert the corresponding PSC information to determine the handover when the measurement report for this PSC is performed as event 1a.

Next, a configuration of performing hard handover between different frequencies using the beacon signal will be described in detail.

FIG. 3 is a block diagram illustrating a configuration of a mobile communication system performing hard handover between frequencies in a border cell of an asynchronous mobile communication network according to an embodiment of the present invention, and FIG. 4 is a diagram of neighbor base station list information according to an embodiment of the present invention. Represents the format configuration.

As shown in FIG. 3, the mobile communication system includes a mobile station 100, a base station 200, 300, and a radio network controller 400.

When entering the border cell area or entering the beacon cell area, the mobile station 100 measures the power of the neighbor cell and reports the event 1a type measurement report including the neighbor base station list information to the radio network controller 400.

Here, the neighbor base station list information is received by the mobile station 100 from the base stations 200 and 300 and managed in two ways as shown in FIG. 4.

4A shows a border neighbor list and FIG. 4B shows a general neighbor list. Both the border neighbor list and the general neighbor list are configured with PSC and Cell ID as items, but the border neighbor list further includes a Configuration FA item.

The border neighbor list may further include a configuration FA item to manage the actual FA so that frequency information may be provided during radio bearer reconfiguration.

The border neighbor list includes cell information adjacent to the border cell and indicates neighbor cell information to be transmitted to the mobile station 100 as the serving FA's intra FA. this is This is because the actual neighbor list and the neighbor list received by the mobile station 100 may be different. That is, the mobile station 100 receives a target frequency of 2FA that is the same as the serving frequency in the border cell, but the target frequency is actually 1FA. Accordingly, the border neighbor list is information for distinguishing the neighbor frequency from the neighbor list in which the target frequency is actually transmitted to 1FA in the border cell.

The normal neighbor list indicates cell information adjacent to the serving cell as in the past. The general neighbor list indicates neighbor list information in which the frequency information of the neighbor base station stored in the base station and the frequency information received by the actual mobile station 100 are the same.

In addition, if the mobile station 100 does not receive a response to the measurement report from the wireless network controller 400, the mobile station 100 repeatedly performs the measurement report.

The mobile station 100 performs an Active Set Update of the base station when a response to the measurement report is received. The radio bearer reconfiguration for hard handover is performed to the target base station according to the handover decision of the radio network controller 400.

In addition, the target base station 300 includes a beacon transmitter 320 for generating a common channel signal to support the hard handover of the mobile station 100.

The beacon transmitter 320 is a component for transmitting a frequency channel necessary for requesting a handover to the target base station 300, and provides the mobile station 100 with information about the target base station 300 at the request of the radio network controller. The beacon transmitter 320 includes PN (Pseudo Noise) information and FA information of the target base station 300. The beacon transmitter 320 has the parameters required for generating the common channel and transmits a beacon signal composed of only the transmission common channel necessary for the measurement report for handover of the mobile station 100. The mobile station 100 obtains system information of the target base station 200 including the beacon frequency for hard handover by receiving the beacon signal.

The base station controller 340 is included in the serving base station 200 and the target base station 300 to interwork with the radio network controller 400 to perform a process for hard handover of the mobile station 100. The base station controller 340 performs processing related to radio link setup including radio link setup / deletion and neighbor base station list management shown in FIG. 4.

In addition, the radio network controller 400 communicates with the mobile station 100, the serving base station 200, and the target base station 300 to control hard handover between different frequencies using the beacon signal of the mobile station 100.

The radio network controller 400 includes a measurement report processor 420, a radio bearer processor 440, a radio link processor 460, and a handover determiner 480.

The measurement report processor 420 receives a measurement report including information on the neighbor cell measured by the mobile station 100. The measurement report processor 420 performs an active set update of the mobile station 100 and the base station according to whether a cell is updated through information included in the measurement report. In this case, when the cell update is not performed, that is, the mobile station 100 repeatedly receives one or more measurement reports.

Here, the measurement report processor 420 receives a measurement report from the mobile station 100 through a measurement report message (MRM). The measurement report message is composed of parts, such as a measurement ID and a measurement result. In this case, the handover decision to be described below is applicable when the measurement ID is event 1a and the measurement result is an intra frequency measurement result type.

The radio bearer processing unit 440 performs a procedure of reconfiguring the radio bearer with the mobile station 100 so that the mobile station 100 performs hard handover between different frequencies from the serving base station 200 to the target base station 300.

The radio link processor 460 releases the radio link connected to the serving base station 200 and sets up the radio link with the target base station 300 to perform hard handover between different frequencies.

The handover decision unit 480 determines whether to handover the mobile station 100 based on the measurement report received from the measurement report processor 420, and then controls operations of the radio bearer processor 440 and the radio link processor 460. To perform a handover. The operation of the handover decision unit 480 will be described with reference to FIG. 5.

FIG. 5 is a block diagram illustrating a detailed configuration of a handover decision unit in FIG. 4, and FIG. 6 shows handover triggering setting information.

As shown in FIG. 5, the handover decision unit 480 includes a handover type selection module 481, an inter-frequency hard handover module 482, and an intra-frequency hard handover module 483.

The handover type selection module 481 performs a function of distinguishing a general inter FA hard handover type from an intra FA hard handover type according to an embodiment of the present invention. At this time, the handover type selection module 481 determines whether the preferred cell of the mobile station 100 is the border cell and whether the beacon cell information for transmitting the beacon signal is included in the neighbor base station information included in the measurement report. That is, it is determined whether the cell which has performed the active set update with the mobile station is a border cell. In addition, the received measurement report confirms whether the PSC of the event 1a is a border neighbor list, that is, includes beacon cell information.

When the inter-frequency hard handover module 482 does not include the beacon cell information in the preferred cell of the mobile station 100 or the neighbor base station information according to the selection result of the handover type selection module 491, Perform hard handover of inter frequency mode type.

Intra frequency hard handover module 483 is the intra frequency mode when the preferred cell of mobile station 100 is a border cell or beacon cell information is included in neighboring base station information according to the selection result of handover type selection module 491. Perform a hard handover of type.

Here, the intra frequency hard handover module 483 includes a triggering information checking module 484, a timer triggering module 485, a counter triggering module 486, a storage unit 487, and a handover control module 488. .

The triggering information check module 484 checks a predefined handover triggering scheme. At this time, a handover triggering scheme for preventing a ping pong may be a counter based or timer based scheme.

The timer triggering module 485 performs timer-based handover triggering according to the verification result of the triggering information confirming module 484. At this time, the timer triggering module 485 determines the handover when the continuous occurrence of the event 1a exceeds the reference value (hereinafter, referred to as the event 1a border timer threshold value).

The counter triggering module 486 performs counter-based handover triggering according to the verification result of the triggering information confirming module 484. In this case, the counter triggering module 486 determines the handover when the continuous occurrence of the event 1a exceeds a reference value (hereinafter, referred to as an event 1a border counter threshold value).

Here, the timer triggering module 485 and the counter triggering module 486 do not determine the handover when they do not exceed the respective threshold values, and thus receive the measurement report according to the handover triggering event again.

The storage unit 487 stores information on whether it is timer-based or counter-based, information on parameter values on each triggering method, that is, an event 1a border timer threshold or an event 1a border counter threshold. The parameter value may be stored as shown in FIG. 6. In this case, the event 1a border timer threshold value may be set to '0 to 10000' using a millisecond (msec) unit. In addition, the event 1a border counter threshold may be set to '0 to 20' as the number of times.

The handover control module 488 is connected to the timer triggering module 485 and the counter triggering module 486 to control operations of the radio bearer processing unit 440 and the radio link processing unit 460 when it is determined to perform handover. Inter-frequency hard handover is controlled from the frequency of the serving base station to the frequency of the target base station.

In this case, when a plurality of frequencies of the target base station are operated, the handover control module 488 checks the frequency of the target base station through the received measurement report and performs hard handover to a frequency having the largest signal strength. If the hard handover fails, the operation of repeatedly performing the hard handover at the next highest frequency is performed. When performing repetition, handover triggering, that is, timer-based or counter-based triggering, may be omitted.

A process of performing inter-frequency hard handover using a beacon signal will be described based on the above configuration.

7 is a flowchart illustrating a method for performing hard handover between frequencies in a border cell of an asynchronous mobile communication network according to an embodiment of the present invention.

As shown in FIG. 7, when a handover triggering event occurs, the mobile station performs frequency measurement of an adjacent cell (S101).

The mobile station receives system information from the serving base station Node B and the target base station Node B to obtain neighbor base station information (S103, S105). In this case, the neighbor base station information includes information about the neighbor cell including the border neighbor list and the general neighbor list described above.

Then, the mobile station transmits a measurement report including the neighbor base station information received in steps S103 and S105 to the radio network controller as a result of the measurement in step S101 (S107). At this time, if the mobile station does not receive a response to the measurement report from the wireless network controller, the mobile station repeatedly transmits one or more measurement reports (S109). Here, event 1a is used as the handover triggering type of the measurement report.

If it is determined that cell update is necessary through the measurement report received in steps S07 and S109, the radio network controller performs an active set update with the mobile station in response to the measurement report (S111).

After performing the active set update, the mobile station transmits a measurement report including the newly added cell information to the radio network controller (S113). Here, event 1d is used as the handover triggering type of the measurement report.

The radio network controller determines whether hard handover between frequencies is performed based on the measurement report of the mobile station (S115).

When the inter-frequency hard handover is determined in step S115, the radio network controller sets a radio link by transmitting a radio link setup request to the target base station Node B (S117) and receiving a response (S119).

The radio network controller then performs hard handover to the mobile station and the FA currently in service through radio bearer reconfiguration or physical channel reconfiguration (S121, S123).

The wireless link is released by transmitting a radio link deletion request connected to the serving base station Node B (S125) and receiving a response (S127).

FIG. 8 is a flowchart illustrating a method for determining inter-frequency hard handover in a border cell of an asynchronous mobile communication network according to an embodiment of the present invention, which is a flowchart illustrating step S115 of FIG. 8 in more detail.

As shown in FIG. 8, the radio network controller first determines whether a primary cell is a border cell (S201). That is, it is checked whether the preferred cell added to the measurement report of the triggering event 1d is a border cell or a normal cell.

At this time, the cell is included in an active set, which is a group of cells (base station) that can communicate with the mobile station, and means a main communication counterpart determined based on the received signal strength of the mobile station. In this regard, there is a non-primary cell that is included in the active population and is a secondary communication counterpart.

As a result of checking in step S201, in the case of the border cell, it is determined whether the PSC of the received event 1a is included in the border neighbor list (S203). That is, the mobile station reports the signal strength measured according to a predetermined number of measurements because it does not know whether the cell entered is the border cell or not. The radio network controller then determines whether the PSC of event 1a of the measurement report is a beacon signal or not.

In this case, when the first cell is not the border cell or the PSC of the received event 1a is not the beacon signal as a result of the determination in steps S201 and S203, a general inter-frequency hard handover is performed (S205).

In addition, as a result of the determination in step S203, when the PSC of the received event 1a is included in the border neighbor list, it is determined whether to operate based on a timer or a counter based (S207). At this time, whether timer-based or counter-based can be selected and used, respectively, according to a predefined method.

As a result of the determination in step S207, when the operation is based on the timer, it is determined whether the continuous occurrence time of the event 1a exceeds the set event 1a border timer threshold value (S209).

Alternatively, in operation S207, when the operation is based on the counter, it is determined whether the number of consecutive occurrences of the event 1a exceeds the set event 1a border counter threshold (S211).

In this case, when the determination result in step S209 or S211 does not satisfy the threshold condition of the timer-based and counter-based, the process returns to step S201 and repeats steps S201 to S211.

However, if it is determined in step S209 or step S211 that the threshold conditions based on timers and counters are satisfied, the radio link is set up with the target base station Node B and the radio link with the serving base station Node B is released ( S213).

The mobile station and the radio bearer are reconfigured or hard handover is performed through channel reconfiguration (S215).

9 is a flowchart illustrating another embodiment of step S213 of FIG. 8.

As shown in FIG. 9, the radio network controller uses the FA (preferred frequency) having the largest signal strength in the measurement report when the FA of the target base station Node B operates as a multi-FA, and sets up a radio link setup and a radio bearer reconfiguration. Perform (S301).

At this time, if the radio link setup and radio bearer reconfiguration fail due to the lack of resources of the frequency (S303), step S301 is performed again using the FA with the next largest signal strength of the target base station Node B (S305). ).

In addition, if the radio link setup and radio bearer reconfiguration is successful (S303), a next handover procedure, that is, a procedure of terminating the radio link connection of the serving base station Node B, is performed (S307).

Meanwhile, although the event 1a is used as the handover triggering event in the above description, the event 1E may be used. If event 1E is used, it is set as a condition prior to event 1a and the handover procedure is applied in the same manner as event 1a. At this time, the event IE indicates a handover triggering event when the beacon signal is more than a predetermined threshold.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a conceptual diagram illustrating a configuration of a cell performing frequency hard handover in a border cell of an asynchronous mobile communication network according to an embodiment of the present invention.

2 is a conceptual diagram of performing hard handover between frequencies in a border cell of an asynchronous mobile communication network according to an embodiment of the present invention.

3 is a block diagram illustrating a configuration of a mobile communication system performing hard handover between frequencies in a border cell of an asynchronous mobile communication network according to an embodiment of the present invention.

4 illustrates a format configuration of neighbor base station list information according to an embodiment of the present invention.

FIG. 5 is a block diagram illustrating a detailed configuration of a handover decision unit in FIG. 4.

6 shows handover triggering setting information.

7 is a flowchart illustrating a method for performing hard handover between frequencies in a border cell of an asynchronous mobile communication network according to an embodiment of the present invention.

8 is a flowchart illustrating a method for determining inter-frequency hard handover in a border cell of an asynchronous mobile communication network according to an embodiment of the present invention.

9 is a flowchart illustrating another embodiment of step S213 of FIG. 8.

Claims (15)

In the asynchronous mobile communication system performing a hard hand-over frequency between the serving base station using the first frequency to the target base station using the second frequency, A beacon transmitter for transmitting a beacon signal including information about the target base station to the mobile station using the first frequency; And Receiving a measurement report for the first frequency including information on the target base station from the mobile station, and when the preferred cell of the mobile station is a border cell where the serving cell of the mobile station and the target cell intersect the measurement report based on the measurement report A radio network controller performing hard handover between frequencies of the mobile station from a first frequency to the second frequency. Asynchronous mobile communication system comprising a. The method of claim 1, The wireless network controller, A measurement report for receiving the measurement report including information on the target base station and neighbor base station information measured according to a preset handover triggering event from the mobile station to perform an active set update of the base station with the mobile station; Processing unit; And A handover decision unit for determining the hard handover between frequencies when the preferred cell updated by performing the active set update of the base station is the border cell and the neighbor base station information includes beacon cell information for transmitting the beacon signal. Asynchronous mobile communication system comprising a. The method of claim 2, The handover determination unit, A handover type selection module for determining whether the first cell is a border cell and whether the beacon cell information is included in the neighbor base station information included in the measurement report based on one or more of the measurement reports received by the measurement report processor; An inter-frequency hard handover when the first cell is not a border cell or the beacon cell information is not included in the neighbor BS information according to the determination result of the handover type selection module. Frequency hard handover module; And Intra-frequency hard hand for performing an intra frequency mode hard handover when the preferred cell is a border cell and the beacon cell information is included in the neighbor base station information according to the determination result of the handover type selection module. Over module Asynchronous mobile communication system comprising a. The method of claim 3, The intra frequency hard handover module, A triggering information checking module for checking whether the preset handover triggering information is timer-based or counter-based; When the preset triggering information is timer based, when the one or more measurement reports received through the measurement report processing unit continuously receive a time exceeding a preset border timer threshold, the hard handover of the intra frequency mode is performed. A timer triggering module for performing; When the preset triggering information is counter based, when the number of the one or more measurement reports received through the measurement report processing unit exceeds a preset border counter threshold, counter triggering to perform hard handover in the intra frequency mode. module; And A storage unit which stores the handover triggering information, the border timer threshold value and the border counter threshold value Asynchronous mobile communication system comprising a. The method of claim 4, wherein The intra frequency hard handover module, When a plurality of the second frequencies are operated, the hard report is performed at the frequency with the largest signal strength through the measurement report, and when the hard handover to the largest frequency fails, the signal strength is next higher. Handover control module that repeats the operation of performing hard handover with frequency Asynchronous mobile communication system further comprising. The method according to any one of claims 2 to 5, The measurement report processing unit, Intra-frequency measurement Asynchronous mobile communication system for receiving the measurement report sent by the mobile station when a triggering event occurs. The method according to any one of claims 2 to 5, The measurement report processing unit, And receiving the measurement report transmitted by the mobile station when a triggering event occurs in which the beacon signal exceeds a preset threshold. The method according to any one of claims 1 to 5, The measurement report, A neighbor base station list of the mobile station, wherein the neighbor base station list includes a border neighbor list including neighbor base station information of a border cell for converting and transmitting the second frequency into the first frequency, and frequency information received by the mobile station; The frequency information received by the base station includes a general neighbor list including the same neighbor base station information, The border neighbor list includes neighbor base station information of a border cell including a first scrambling code (PSC) measured by the mobile station, an identifier (ID) of a corresponding cell, and actual frequency information allocated to the corresponding cell. Asynchronous mobile communication system comprising. A method for performing a hard handover between frequencies from a serving base station using a first frequency to a target base station using a second frequency in an asynchronous mobile communication network, Transmitting a beacon signal including information about the target base station to a mobile station using the first frequency; Receiving a measurement report for the first frequency from the mobile station that includes information about the target base station; And Performing hard handover between the frequencies of the mobile station from the first frequency to the second frequency based on the measurement report when the preferred cell of the mobile station is a border cell where the serving cell of the mobile station and the target cell intersect. Inter-frequency hard handover method comprising a. The method of claim 9, Performing the hard handover, Receive one or more measurement reports including information on the target base station and neighbor base station information measured by the mobile station according to a preset handover triggering event from the mobile station, and determine whether the preferred cell is a border cell based on the measurement report. Determining whether the beacon cell information transmitting the beacon signal is included in the measurement report; Performing hard handover in an interfrequency mode when the preferred cell is not a border cell or the neighbor base station information does not include the beacon cell information; And Performing hard handover in an intrafrequency mode when the preferred cell is a border cell and the neighbor base station information includes the beacon cell information; Inter-frequency hard handover method comprising a. The method of claim 10, The hard handover of the intra frequency mode may be performed by: Checking whether the preset handover triggering information is timer-based or counter-based; When the preset triggering information is timer-based, performing hard handover in the intra frequency mode when the one or more measurement reports continuously received exceeds a preset border timer threshold value; And Performing hard handover in the intra frequency mode when the number of the one or more measurement reports exceeds a preset border counter threshold value when the preset triggering information is counter based. Inter-frequency hard handover method comprising a. The method of claim 11, The hard handover of the intra frequency mode may be performed by: Attempting hard handover of the timer-based or counter-based intra-frequency mode at a frequency having the largest signal strength through the measurement report when a plurality of second frequencies operated by the target base station are operated; And Performing hard handover in the intra frequency mode at a frequency where the signal strength is next highest when the hard handover to the largest frequency fails. Inter-frequency hard handover method comprising a. The method according to any one of claims 9 to 12, The receiving step, Intra Frequency Measurement A method for hard handover between frequencies that receives the measurement report sent by the mobile station when a triggering event occurs. The method according to any one of claims 9 to 12, The receiving step, And receiving the measurement report transmitted by the mobile station when a triggering event occurs in which the beacon signal exceeds a preset threshold. The method according to any one of claims 9 to 12, The measurement report, A neighbor base station list of the mobile station, wherein the neighbor base station list includes a border neighbor list including neighbor base station information of a border cell for converting and transmitting the second frequency into the first frequency, and frequency information received by the mobile station; The frequency information received by the base station includes a general neighbor list including the same neighbor base station information, The border neighbor list includes neighbor base station information of a border cell including a first scrambling code (PSC) measured by the mobile station, an identifier (ID) of a corresponding cell, and actual frequency information allocated to the corresponding cell. Including hard handover between frequencies.

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