KR100262229B1 - Handoff method of cdma mobile communication system - Google Patents

Abstract

The present invention transmits only a specific pilot strength measurement message (PSMM) to the call processing control unit (CCP) and the remaining pilot strength measurement message (PSMM) except for the specific pilot strength measurement message (PSMM) is processed by the call processing and voice processing unit (TSB). Accordingly, to provide a handoff method of a CDMA mobile communication system that can reduce the PSMM processing load of the CCP and improve the handoff speed, the present invention transmits a PSMM requesting a handoff to a new base station to the CCP The remaining PSMM excluding this PSMM decides the handoff type in the TSB without transmitting to the CCP. The TSB instructs the CE to perform the handoff according to the determined handoff type after making the handoff type decision. In this way, only a specific PSMM is transmitted to the CCP to speed up the handoff and reduce the load on the CCP.

Description

Handoff Method of CDM Mobile Communication System

The present invention relates to a hand-off method of a mobile communication system such as a digital cellular system (DCS) and a personal communication system (PCS) using a code division multiple access (CDMA) scheme. In particular, the handoff type at the time of handoff is not determined solely by a Call Control Processor (hereinafter, abbreviated as "CCP") of a base station controller (BSC). Transcoder and Selector Bank (hereinafter abbreviated as "TSB") to determine a hand-off method for a CD-A mobile communication system that can be performed by the control of the TSB.

In general, a mobile communication system is a system that operates to receive a communication service while the mobile station moves. Thus, when the mobile station is included in the service area (cell) of one base station and is provided with the service of the base station, when the mobile station is moved to the service area of the neighboring base station, a hand off is performed to the mobile station. It is operated to continue to receive communication service.

2 is a flowchart illustrating a handoff method of a conventional mobile communication system.

As shown here, when a PSMM (Pilot Strength Measurement Message) requesting handoff is transmitted from the mobile station, a first step (ST1-ST2) of TSB sending all the transmitted PSMMs to CCP; A second step (ST3) of the CCP determining the handoff type with reference to the PSMM transmitted from the TSB and then transmitting the determined handoff type to the TSB; After performing the handoff according to the handoff type received from the CCP, if the handoff is successfully completed, a third step (ST4-ST5) is provided to notify the CCP of the handoff completion.

Referring to the handoff method in the conventional mobile communication system as follows.

First, a mobile station moving between cells searches for and measures a pilot power strength received from an adjacent base station, and transmits a pilot strength measurement message (PSMM) to a TSB of a control station if a handoff request situation occurs. ST1). The TSB then analyzes the received PSMM and sends all PSMMs to the CCP (ST2), which CCP refers to this PSMM to determine the handoff type.

The handoff types include soft hand off between sectors, hard hand off between exchanges, and soft hand off between base stations. Each handoff includes a set of pilot signals of a serving base station, that is, when a pilot signal of a new base station is added (ADD) to an active set and a corresponding pilot signal of the pilot signals of the active set is removed (DROP) and an active set. It is divided into a case in which a pilot signal of is dropped (DROP) and a new pilot signal is added to the active set (ADD).

After determining one of these handoff types, the CCP sends the determined handoff type to the TSB (ST4). Then, the TSB performs handoff according to the received handoff type (ST4). If the handoff is successfully completed, the TSB reports the successful completion of the handoff to the CCP (ST5), and the CCP reports the handoff result back to the switching center. Thus, mobile stations moving between cells can be continuously provided with a mobile communication service without interruption.

However, the handoff method of the conventional CDMA mobile communication system determines the handoff type only in the CCP of the control station, so that all PSMMs from the mobile station sequentially pass through the TSB and CCP of the control station, and then the handoff is performed under the control of the CCP. Therefore, there was a problem that the handoff speed was lowered.

In addition, since the handoff speed is lowered, there is a problem that the failure rate of the handoff is lowered, thereby lowering the reliability of the service.

In addition, since the PSMM is transmitted to the CCP, which is unnecessary for handoff, there is also a problem in that the CCP is heavily loaded with PSMM processing.

In addition, when the strength of the pilot signal of the new base station becomes greater than a predetermined value and includes the pilot signal as an active set, the number of additional pilots is limited to one, so that the mobile station does not fully reflect the handoff request of the mobile station. There were also disadvantages. In the case where the pilot signal in service to the mobile station drops below the set value and the pilot signal is removed from the active set, the handoff is performed by limiting the number of pilot signals that can be removed to one. There was a disadvantage in that it does not fully reflect the mobile station's handoff request.

Accordingly, the present invention has been proposed to solve the above-mentioned conventional problems, and an object of the present invention is to give a call processing and voice processing unit (TSB) of a control station a function of determining a handoff type, thereby providing a specific handoff. In the case of the present invention is to provide a hand-off method of the CDA mobile communication system that can improve the speed of performing the handoff by performing the handoff only by the control of the call processing and the voice processing unit, not the control of the call processing control unit.

In order to achieve the above object, a hand-off method of a CDA mobile communication system according to the present invention,

A PSMM analysis step of analyzing, by the call processing and voice processing unit (TSB), a pilot strength measurement message (PSMM) transmitted from the mobile station; A handoff type determination step of determining, by the TSB, the handoff type if the PSMM requesting handoff for which processing by the call processing control unit (CCP) is not required; According to the determined handoff type, after the handoff procedure is performed in the TSB and the handoff is completed, the handoff performing step of reporting the completion of the handoff to the CCP is characterized in that the method configuration.

The determining of the handoff type may include: determining whether to remove a pilot to be added and to determine if a pilot to be removed exists in the TSB as a mixed removal type (TSB_MIX_DROP); A mixed exchange determining step of determining, by the PSMM analysis, that the addition of a pilot of an active base station requires a pilot to be removed and a mixed exchange type (TSB_MIX_SWAP) in the TSB; As a result of the PSMM analysis, if addition of a pilot of an active base station is required, and there are no pilots to be removed, and there are not six active sets, a mixed addition determination step of determining by TSB as a mixed addition type (TSB_SOFTER_ADD) and ; As a result of the PSMM analysis, the addition of a pilot of an active base station is required, there are no pilots to be removed, there are six active sets, two or more active pilots of the corresponding base station, and a pilot to be added (ADD) is larger than this active pilot. It is characterized in that it consists of a softer exchange decision step in which the TSB determines the softer exchange type (SOFTER_SWAP) if it is the highest or there is a difference of more than a certain intensity (T_COMP) from the active pilot.

The performing of the handoff may include: batching SOFTER_DROP and SOFT_DROP at the same time, if the mixed removal type (TSB_MIX_DROP) is determined in the handoff type determination step; If it is determined in the handoff type determination step as the mixed addition type (TSB_SOFTER_ADD), the TSB processes SOFTER_ADD; If the mixed exchange type (TSB_MIX_SWAP) is determined in the handoff type determination step, the TSB simultaneously processes TSB_SOFTER_ADD, SOFTER_DROP, SOFTER_SWAP or SOFT_DROP; If it is determined in the handoff type determination step that the softer exchange type SOFTER_SWAP is determined, the TSB is configured to process the SOFTER_SWAP.

1 is a block diagram of a CDMA mobile communication system to which the present invention is applied;

2 is a flowchart illustrating a handoff method of a conventional CDMA mobile communication system;

3 is a flowchart illustrating a procedure in which a conventional softener_add type (SOFTER_ADD) is performed;

4 is a flowchart illustrating a procedure in which a conventional SOFTTER_DROP is performed;

5 is a flowchart illustrating a procedure in which a conventional soft_removal type SOFT_DROP is performed;

6 is a flow chart showing a procedure in which a conventional SOFT_SWAP type is performed;

7 is a flowchart illustrating a handoff method of a CDMA mobile communication system according to the present invention;

8 is a flowchart illustrating a procedure of performing TSB_SOFTER_ADD according to the present invention;

9 is a flowchart illustrating a procedure of performing TSB_MIX_DROP according to the present invention;

10 is a flowchart illustrating a procedure of performing TSB_MIX_SWAP according to the present invention.

<Description of the code | symbol about the principal part of drawing>

1: mobile station 2: base station

3: channel element 4: base station controller

5: control station 6: call processing and voice processing unit

7: Call processing control section 8: Switching station

Hereinafter, the handoff method of the present invention CDMA mobile communication system will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a CDMA mobile communication system to which the present invention is applied.

As shown therein, the strength of the pilot signal from the serving base station 2 and the neighboring base station is measured and included in the Pilot Strength Measurement Message (PSMM) to transmit the handoff request message to the base station 2. A mobile station 1 to make; A base station 2 for connecting the mobile station 1 and the control station 5; A control station (5) which analyzes the PSMM from the mobile station (10) transmitted through the base station (2), determines a handoff type, and performs handoff; It consists of an exchange station (8) which reports the handoff result carried out under the control of the control station (5) and continuously provides a telecommunication service to the mobile station (1).

The base station 2 is a channel element (CE) 3 connecting the mobile station 1 and the control station 5 and the mobile station 1 under the control of the control station 5. And a base station controller (BCP) 4 that manages and controls the forward signal and the forward power to be allocated.

The control station 5 analyzes the PSMM transmitted from the channel element 3 of the base station 2 and then requests a handoff requiring control of the call processing control unit 7 to call the control unit 7. A call processing and voice processing unit (TSB) 6 for performing a handoff by referring to a PSMM requesting a handoff that does not require control of the call processing control unit 7, and the call processing and voice processing unit 6. And a call processing control unit (CCP) 7 for determining a handoff type with reference to the PSMM transmitted from the multicast device and transmitting the determined handoff type to the call processing and voice processing unit 6.

In the present invention, the TSB can manage up to three active base stations, and up to six active sets. In addition, up to three sectors within the same base station may be active pilots. In addition, the number of pilots added may be up to two for each base station, and the number of pilots removed may be up to three for each base station.

Under this constraint, the handoff method according to the present invention applied to and performed in the CDMA mobile communication system is shown in FIG.

First, the TSB 6 performs PSMM analysis steps 111-112 for analyzing the PSMM transmitted from the mobile station 1. As a result of the analysis, if the PSMM requires a handoff for which the processing of the CCP 7 is not required, the TSB 6 performs the handoff type determination steps 113-129 for determining the handoff type. In addition, as a result of the analysis, if the handoff request PSMM requiring the processing of the CCP (7), the PSB is transmitted from the TSB (6) to the CCP (7), and the handoff type is determined by referring to the PSMM received from the CCP (7) A handoff type transmission step 133 for transmitting the handoff type to the TSB 6 is performed. After performing the handoff procedure in the TSB 6 according to the handoff type thus determined and performing handoff when the handoff is completed, the handoff completion step 130-131 reports the completion of the handoff from the TSB 6 to the CCP 7. Perform

In the handoff type determination step 113-129, if there is no pilot to be added and there is a pilot to be removed as a result of the analysis of the PSMM, the demixing decision step 113-determined as the mixed removal type (TSB_MIX_DROP). 117). If the PSMM analysis indicates that the addition of the pilot of the active base station is required and there is a pilot to be removed, the mixed exchange decision steps 118-122 of determining the mixed exchange type (TSB_MIX_SWAP) are performed. As a result of the PSMM analysis, if addition of a pilot of an active base station is required, and there are no pilots to be removed, and there are not six active sets, a mixed addition determination step of determining a mixed addition type (TSB_SOFTER_ADD) is performed. 120) 123-125. As a result of the PSMM analysis, the addition of a pilot of an active base station is required, there are no pilots to be removed, there are six active sets, two or more active pilots of the corresponding base station, and a pilot to be added (ADD) is larger than this active pilot. Softer exchange decision steps 118-120 (126-129) are performed to determine the softest exchange type (SOFTER_SWAP) if it is the highest or there is more than a certain intensity (T_COMP) difference from the active pilot.

The handoff method of the CDMA mobile communication system according to the present invention will be described in detail as follows.

First, the TSB 6 receives a pilot offset for each sector of the active base station from the CCP 7 at the beginning of call setup, and for each sector of the active base station whenever a new base station is added. Receive a pilot offset value.

After the mobile station 1 moving between cells searches for and measures the pilot power strength received from the neighboring base station, and if a handoff request situation occurs, the mobile station 1 sends a pilot strength measurement message (PSMM). Transmit to base station 2. This PSMM includes data such as an active pilot serving an mobile station 1, an offset of a candidate pilot, pilot strength, and the like. The base station 2 then transmits this PSMM to the TSB 6 of the control station 5, and the TSB 6 analyzes the PSMM received from the base station 2.

That is, the TSB 6 sorts the pilots included in the PSMM in the order of pilot power intensity (111), and then searches (112) the pilot (Add Pilot) to be added. The pilot to be added represents all the pilots whose pilot power strength is greater than or equal to the constant T_ADD among the candidate pilots (not pilots in service but pilots having sufficient power strength for the mobile station to demodulate the signal).

If this additional pilot does not exist, the number of active sets is checked, and if there is one active set, no handoff is performed. However, if there are two or more active sets and there are no pilots to be added, the controller searches for whether there are pilots to be removed from the pilots of the active set (115). The pilot to be removed represents a pilot whose power strength has fallen below a certain intensity (T_DROP) for a period of time among the current active pilots (pilot serving the mobile station).

If there is such a pilot to be removed, the TSB 6 determines the handoff type as the mixed removal type (TSB_MIX_DROP). This TSB_MIX_DROP is a handoff type which is a mixture of a conventional soft remover type (SOFTER_DROP) and a soft remove type (SOFT_DROP).

Here, referring to the conventional softener removal type SOFTER_DROP, as shown in Fig. 4, the TSB 6 receiving the PSMM from the mobile station 1 transmits the PSMM to the CCP 7, and the CCP 7 ) Determines SOFTER_DROP by this PSMM. This SOFTER_DROP is then directed to the TSB 6 (31-33). Thus, since the conventional TSB 6 transmits the PSMM from the mobile station 1 to the CCP 7 irrespective of the handoff type, the PSMM processing load of the CCP 7 is heavily applied.

The TSB 6 having received the SOFTER_DROP indication informs the mobile station 1 of a new active set (set of pilots in service to the mobile station) (34). The mobile station 1 then informs the TSB 6 that the active set has been modified (35). TSB 6 then informs CE 3 that SOFTER_DROP has ended 36, and CE 3 terminates handoff termination to BCP 4 to allow BCP 4 to recover the code channel and forward power. Inform (37). The TSB 6 then reports to the CCP 7 that the SOFTER_DROP procedure has been successfully performed, and the CCP 7 notifies the MSC 8 that a handoff has occurred (38-39).

Next, referring to the conventional SOFT_DROP, as shown in Fig. 5, upon receipt of the PSMM from the mobile station 1, the TSB 6 sends this PSMM to the CCP 7, which the CCP 7 sends by this PSMM. The SOFT_DROP is determined to indicate the SOFT_DROP to the TSB 6 (41-43). Thus, since the conventional TSB 6 transmits the PSMM from the mobile station 1 to the CCP 7 irrespective of the handoff type, the PSMM processing load of the CCP 7 is heavily applied. After receiving the instruction of the CCP 7, the TSB 6 performs the handoff.

When the TSB 6 receives the instruction of the CCP 7, the TSB 6 notifies the mobile station 1 of the new active set (44), and the mobile station (1) reports that it has been modified after modifying the active set with the new active set notified. (45). TSB 6 then releases the CE of the pilot being removed, and then informs the busy CE that SOFT_DROP is complete (46-47). TSB 6 then reports 48 to CCP 7 that the SOFT_DROP procedure was successfully performed. CCP 7 then informs MSC 8 that a handoff has occurred (49).

However, TSB_MIX_DROP according to the present invention, which is a type of a mixture of such conventional SOFTER_DROP and SOFT_DROP, is determined in the TSB 6 by the PSMM from the mobile station 1, as shown in FIG.

After the TSB_MIX_DROP decision, the TSB 6 notifies the mobile station 1 of the new active set, and the mobile station 1 informs the TSB 6 that the active set has been newly modified (152-153). The TSB 6 then releases the CE of the pilot being removed (154) and notifies the busy CE that SOFT_DROP is complete (155). The TSB 6 notifies the busy CE of the termination of SOFTER_DROP (156). Here, the number of pilots to be removed is not limited to one, but up to two may be possible. Thus, the handoff request of the mobile station 1 is reflected as much as possible.

The TSB 6 then reports to the CCP 7 that the SOFT_DROP and SOFTER_DROP procedures have been successfully performed, and the CCP 7 notifies the MSC 8 that a handoff has occurred (157-158).

In this way, the TSB_MIX_DROP is performed by type determination in the TSB 6 without transmitting the PSMM from the mobile station 1 to the CCP 7, thereby reducing the load due to the PSMM processing of the CCP 7 and handing off. It will speed up the execution.

Next, as shown in FIG. 7, the TSB 6 sorts the pilots included in the PSMM from the mobile station 1 in order of pilot power intensity, and then searches for pilots to be added (111-112). As a result, if there is a pilot to be added, it is checked whether the pilot is included in the active base station. If the pilot to be added is not the pilot of the active base station (the base station in service), the TSB 6 sends this PSMM to the CCP 7 since it is a handoff request PSMM requiring control of the CCP 7. That is, the handoff type to a new base station other than the serving base station, or a handoff type to a new exchange other than the serving exchange should be handed off under the control of the CCP 7. Therefore, the PSMM requesting this handoff is transmitted by the TSB 6 to the CCP 7.

However, except for the PSMM to be transmitted to the CCP 7, the PSMM determines the handoff type by the TSB 6 and performs the handoff procedure according to the determined handoff type.

That is, as a result of checking whether the pilot to be added is included in the active base station, if the pilot to be added is a pilot of the active base station, the TSB 6 searches for the removal pilot with reference to the PSMM (119). As a result, if there is no pilot to be removed 120, the TSB 6 checks whether the number of pilots in the active set is six (123).

Thus, if the number of pilots in the active set is not six, the TSB 6 searches for whether there are more pilots to be added to the additional base station and determines the mixed addition type (TSB_SOFTER_ADD) (124).

A description of the conventional SOFTER_ADD is as follows.

As shown in Fig. 3, upon receipt of the PSMM from the mobile station, the TSB 6 sends this PSMM to the CCP 7 (11-12). Therefore, the CCP 7 determines the SOFTER_ADD with reference to the PSMM, and then instructs the TSB 6 to perform the determined SOFTER_ADD (13). The TSB 6 then performs SOFTER_ADD according to the instruction of the CCP 7. After the PSMM from the mobile station 1 is transmitted to the CCP 7 through the TSB 6, the handoff type is determined, and the handoff is performed according to the determined handoff type, thereby processing the PSMM of the CCP 7. Will increase the load. It also slows down the handoff. In addition, by limiting the number of pilots that can be added to one, there is a disadvantage that does not fully reflect the handoff request of the mobile station 1.

However, as shown in Fig. 8, the TSB 6 according to the present invention determines TSB_SOFTER_ADD by the PSMM from the mobile station 1, and then instructs the CE 3 SOFTER_ADD to perform this TSB_SOFTER_ADD (142). . At this time, the SOFTER_ADD base station is limited to one, and the number of pilots to be added is possible to two, so as to reflect the handoff request of the mobile station 1 to the maximum.

The CE 3 instructed to perform SOFTER_ADD requests the BCP 4 the code channel and forward power allocation of the pilot to be added (143). The BCP 4 allocates the code channel and forward power and notifies the result to the CE 3 (144), and the CE 3 forwards the allocation result of the BCP 4 to the TSB 6 (145).

Thus, the TSB 6 notifies the mobile station 1 of the new active set (146), and the mobile station 1 notifies the TSB 6 that the active set has been modified after modifying the active set (147). TSB 6 also reports to CCP 7 that the SOFTER_ADD procedure was successful, and CCP 7 notifies MSC 8 that a handoff has occurred (149).

In this way, PSB 6 receives the PSMM received from the mobile station and determines TSB_SOFTER_ADD in TSB 6 and performs TSB_SOFTER_ADD without transmitting the PSMM to CCP 7, thereby reducing the PSMM processing load of CCP 7 and handing off. To be done quickly. The number of pilots that can be added is set to two to reflect the handoff request of the mobile station as much as possible.

Next, a method of performing TSB_MIX_SWAP according to the present invention will be described.

As shown in Fig. 7, the TSB 6 analyzes the PSMM from the mobile station 1, and as a result, the pilot to be added is the pilot of the active base station (111-113) and 118, the hand off if there is a pilot to be removed. The type is determined as the mixed exchange type (TSB_MIX_SWAP) (119-122). This TSB_MIX_SWAP is a mixed type of TSB_SOFTER_ADD, SOFTER_DROP, SOFTER_SWAP or SOFT_DROP.

Here, the conventional SOFTER_SWAP will be described.

As shown in Fig. 6, when the PSMM is received from the mobile station 1, the TSB 6 transmits this PSMM to the CCP 7 (51-52). The CCP 7 determines SOFTER_SWAP with reference to this PSMM, and then directs SOFTER_SWAP to TSB 6 (53). TSB 6 instructs SOFTER_SWAP to CE 3 (54). The CE 3 requests the BCP 4 the code channel and forward power allocation of the pilot to be added and returns 55 to the BCP 4 the code channel and forward power of the pilot to be removed.

The BCP 4 then allocates the code channel and forward power of the pilot to be added and notifies the result to the CE 3 (56). The CE 3 transmits the result assigned by the BCP 4 to the TSB 6 (57). The TSB 6 then notifies the mobile station 1 of the new active set 58, and the mobile station 1 notifies the TSB 6 that the active set has been modified after newly modifying the active set with the notified active set ( 59).

The TSB 6 reports to the CCP 7 that the SOFTER_SWAP procedure has been successfully performed (60), and the CCP 7 notifies the MSC 8 that a handoff has occurred.

In this manner, the conventional SOFTER_SWAP transmits the PSMM from the mobile station 1 to the CCP 7, and then determines the handoff type as SOFTER_SWAP by referring to the PSMM in the CCP 7 and performs the handoff with the determined type. 7) instructs the TSB 6 to SOFTER_SWAP, thereby increasing the PSMM processing load of the CCP 7 and decreasing the handoff performance rate.

However, in the present invention, as shown in FIG. 10, when the handoff type is determined by TSMM in TSB 6 as TSB_MIX_SWAP, TSB 6 instructs CE 3 to perform handoff (where TSB_MIX_SWAP is SOFTER_SWAP). And a case where SOFT_DROP is mixed).

The TSB 6 determines TSB_MIX_SWAP by the PSMM and directs SOFTER_SWAP to the CE 3 in service (161-162). The serving CE 3 then requests the BCP 4 the code channel and forward power allocation of the pilot to be added, and returns the code channel and forward power of the pilot to be removed to the BCP 4 (163). The BCP 4 allocates the code channel and forward power of the pilot to be added and sends the result to the CE 3 (164), which sends the result of the BCP 4 assignment to the TSB 6 (165).

The TSB 6 then notifies the mobile station 1 of the new active set, and in response to this notification, the mobile station 1 notifies the TSB 6 that the active set has been modified after the new modification of the active set. .

The TSB 6 releases the CE of the pilot to be removed and notifies the CE 3 in the call that SOFT_DROP is completed (168-169).

The TSB 6 then reports to the CCP 7 that the SOFTER_SWAP and SOFT_DROP procedures were successfully performed, and the CCP 7 notifies the MSC 8 that a handoff has occurred (170-171).

As such, the TSB determines the type with TSB_MIX_SWAP by referring to the PSMM from the mobile station, and then instructs the direct handoff to be performed without being instructed by the CCP, thereby reducing the load caused by the PSMM being transmitted and processed to the CCP. You will be able to increase the speed.

Next, the process of determining the handoff type as SOFTER_SWAP in the TSB 6 will be described.

As shown in Fig. 7, when the PSMM is transmitted from the mobile station 1, the TSB 6 sorts the pilots included in the PSMM in order of pilot power intensity, and then searches for pilots to be added (111-112). As a result, if there is a pilot to be added 113 and the pilot to be added is a pilot of the active base station, the pilot to be removed is searched again (118-119). As a result, if there is no pilot to be removed, it checks whether there are 6 active sets (120, 123). If there are six active sets, it checks whether there is one active pilot, and if it is one, no handoff is performed (126). However, if the active pilot is not one but two or more, the pilot to be added (ADD) checks the sensor than this active pilot (127). Thus, if the pilot to be added is the largest or the pilot to be added is greater than a certain intensity T_COMP greater than the active pilot, the TSB 6 determines the handoff type as SOFTER_SWAP (127-129).

Thus, the TSB 6 instructs the CE 3 to SOFTER_SWAP to perform the handoff procedure without receiving the indication from the CCP 7.

As such, the present invention transmits only the PSMM requesting handoff to a new base station or handoff to a new exchange among the PSMMs from the mobile station to the CCP, and the remaining PSMMs are not transmitted to the CCP, and the handoff type is determined in the TSB. By handoff indication, the PSMM processing load of the CCP is reduced, and the handoff can be performed quickly.

As described above, the handoff method of the CDA mobile communication system according to the present invention analyzes the PSMM from the mobile station and does not transmit the PSMM from the TSB to the CCP when the handoff type does not require the control of the CCP. By directly determining the handoff type in the TSB and instructing the handoff accordingly, the PSMM processing load of the CCP can be reduced.

In addition, since the handoff is performed after the PSMM requiring the handoff is transmitted only from the mobile station to the TSB and not to the CCP, the handoff performance can be improved.

In addition, the conventional SOFTER_ADD, SOFTER_DROP, SOFTER_SWAP, and SOFT_DROP are processed in one handoff instruction without collective processing, thereby improving operation efficiency.

Further, by designating a plurality of pilot numbers to be added and a plurality of pilots to be removed, the handoff request of the mobile station can be reflected as much as possible.

Claims (6)

In the handoff method of a CDMA mobile communication system, A PSMM analysis step of analyzing, by the call processing and voice processing unit (TSB), a pilot strength measurement message (PSMM) transmitted from the mobile station; A handoff type determination step of determining, by the TSB, the handoff type if the PSMM requesting handoff for which processing by the call processing control unit (CCP) is not required; After performing the handoff procedure in the TSB according to the determined handoff type, if the handoff is completed, the handoff performing step of reporting the completion of the handoff from the TSB to the CCP is performed. Off way. The PSMM of claim 1, wherein the PSMM requesting handoff for which the processing of the CCP is not required is performed. A handoff method of a CDMA mobile communication system, characterized in that it indicates the remaining PSMM except for the PSMM requesting handoff to a new base station instead of the serving base station. The method of claim 1, In the analysis of the PSMM, if the handoff request PSMM is required to process the CCP, the TSB transmits the PSMM to the CCP, the CCP determines the handoff type with reference to the PSMM, and then transmits the determined handoff type to the TSB. The handoff method of the CDMA mobile communication system, characterized in that further performing. The handoff request PSMM of claim 3, wherein the processing of the CCP is required. A handoff method of a CDMA mobile communication system, characterized in that it indicates a PSMM requesting handoff to a new base station rather than a serving base station. The method of claim 1, wherein the determining of the handoff type comprises: A mixture elimination determination step of determining, by TSB, a mixture elimination type (TSB_MIX_DROP) if there is no pilot to be added and there is a pilot to be removed; A mixed exchange determining step of determining, by the PSMM analysis, that the addition of a pilot of an active base station requires a pilot to be removed and a mixed exchange type (TSB_MIX_SWAP) in the TSB; As a result of the PSMM analysis, if addition of a pilot of an active base station is required, and there are no pilots to be removed, and there are not six active sets, a mixed addition determination step of determining by TSB as a mixed addition type (TSB_SOFTER_ADD) and ; As a result of the PSMM analysis, the addition of a pilot of an active base station is required, there are no pilots to be removed, there are six active sets, two or more active pilots of the corresponding base station, and a pilot to be added (ADD) is larger than this active pilot. A method of handoff of a CDMA mobile communication system, comprising: a softer exchange decision step of determining, by the TSB, a softer exchange type (SOFTER_SWAP) if it is the highest or there is a difference of more than a certain intensity (T_COMP) from an active pilot. The method of claim 1, wherein performing the handoff comprises: If the mixed-off type (TSB_MIX_DROP) is determined in the handoff type determination step, the TSB simultaneously batches SOFTER_DROP and SOFT_DROP; If it is determined in the handoff type determination step as the mixed addition type (TSB_SOFTER_ADD), the TSB processes SOFTER_ADD; If the mixed exchange type (TSB_MIX_SWAP) is determined in the handoff type determination step, the TSB simultaneously processes TSB_SOFTER_ADD, SOFTER_DROP, SOFTER_SWAP or SOFT_DROP; And if the SOFTER_SWAP is determined in the handoff type determination step, the TSB is configured to process SOFTER_SWAP.