KR100876746B1 - Mthod of measurement for handover from nb-tdd comunication system to gsm comunication system - Google Patents

Abstract

The present invention can measure the received signal strength of the GSM cell due to the lack of a measurable interval when the UE measures the received signal of the GSM cell for handover to the GSM communication system. We propose a method for synchronizing with a cell and solving a problem of failing to identify an identifier of a cell.

Inter-RAT measurement, Measurement failure cause, Radio frequency switching time

Description

Measurement Method for Handover from Narrow-band Time Division Duplexing Multiple Access Communication System to GSM Communication System {MTHOD OF MEASUREMENT FOR HANDOVER FROM NB-TDD COMUNICATION SYSTEM TO GSM COMUNICATION SYSTEM}             

1A illustrates a frame structure in a conventional narrowband time division duplexing multiple access scheme.

FIG. 1B is a diagram illustrating the structure of a first timeslot section and a downlink transmission section in FIG. 1A. FIG.

2a shows a frame structure in a conventional GSM scheme.

FIG. 2B illustrates a structure of a frame including a frequency correction channel (FCCH) and a shared channel (SCH) among frames in FIG. 2A; FIG.

FIG. 2C is a diagram illustrating the structure of a frequency correction channel (FCCH) and a shared channel (SCH) in FIG. 2B.

3 depicts a situation where conventional Inter-RAT measurements are required.

FIG. 4 is a diagram illustrating a time slot capable of inter-RAT measurement in a conventional narrowband time division duplexing multiple access mobile communication system.                 

5 is a diagram illustrating an example of a signal processing procedure for resolving inter-RAT measurement failure during inter-RAT handover according to an embodiment of the present invention.

6 is a diagram illustrating another example of a signal processing procedure for resolving inter-RAT measurement failure in inter-RAT handover according to an embodiment of the present invention.

FIG. 7 illustrates another example of a signal processing procedure for resolving inter-RAT measurement failure during inter-RAT handover according to an embodiment of the present invention. FIG.

8 is a diagram illustrating a signal processing procedure according to an inter-RAT measurement failure in a conventional inter-RAT handover.

9 illustrates another example of a signal processing procedure for resolving inter-RAT measurement failure during inter-RAT handover according to an embodiment of the present invention.

The present invention relates to a handover method between mobile communication systems using different methods in a mobile communication system, and more particularly, to a method for measuring received signal and maintaining synchronization for handover to a mobile communication system using different methods. .

Typically, the third generation mobile communication method refers to a mobile communication method supporting packet service as well as voice service. Code Division Multiple Access (hereinafter referred to as "CDMA") scheme is used. The third generation mobile communication method is 3GPP (3rd Generation Project Partnership) or UMTS, a European and Japanese standard method based on asynchronous communication between base stations, and 3GPP2 (3rd Generation), a US standard method based on synchronization between base stations. Project Partnership 2) or CDMA2000. Among the third generation mobile communication methods, 3GPP uses frequency division duplexing (FDD) for distinguishing up / down transmission and reception by frequency and time division duplexing for distinguishing up / down transmission and reception by time. Time Division Duplexing, hereinafter referred to as "TDD"). The mobile communication system using the TDD scheme uses broadband time division duplexing (hereinafter referred to as "WB-TDD") using a chip rate of 3.84 Mcps (Mega chip per second) and a chip rate of 1.28 Mcps. Is narrowband time division duplexing (hereinafter referred to as "NB-TDD").

The second generation mobile communication method before the third generation mobile communication method includes GSM (Global System for Mobile Communications), IS (Interim Standard) -95, and the like. Among the second generation mobile communication methods, the GSM was commercialized mainly in Europe in 1992. The GSM provides a service using a time division multiple access (TDMA) method. Meanwhile, among the second generation mobile communication methods, the IS-95 has been commercialized mainly in Korea and the United States, and provides a service using a CDMA method.

As described above, the second generation mobile communication system and the third generation mobile communication system use different frequencies or communication methods, and the different mobile communication systems may exist adjacent to each other in various regions. In particular, as the service by the third generation mobile communication system is commercialized, base stations supporting different schemes such as FDD, WB_TDD, NB_TDD, GSM, cdma2000, and IS-95 described above may exist adjacent to each other.

On the other hand, one of the important features of the third generation mobile communication system will be said to support a global roaming (Global roaming) service regardless of the communication method or frequency used in the mobile communication system. Therefore, the third generation mobile communication systems must support handover to the second generation mobile communication system or the third generation mobile communication systems described above. That is, if a mobile station (UE) moves away from the base station area currently receiving service to a base station area using a different communication method or frequency, handover between base stations supporting the different communication methods or frequencies for global roaming service. Is necessary.

As described above, due to the development of communication technologies, mobile communication systems using various communication methods are commercialized, and thus, a handover method between mobile communication systems using different communication methods or frequencies in a mobile communication environment in which different communication methods are mixed. Was required.

As described above, handover between mobile communication systems using different communication methods is referred to as "inter-RAT handover". Monitoring the status of a base station of a mobile communication system using another communication method for the inter-RAT handover is referred to as "inter-RAT measurement". In addition, since different frequencies may be used between adjacent base stations even between base stations using the same communication scheme, handover may occur between base stations using different frequencies as described above. Such handover is referred to as "Inter frequency handover", and monitoring the state of a base station using a different frequency for the "Inter frequency handover" is called "Inter frequency measurement".

Various methods are used in the third generation mobile communication method for the inter frequency measurement or the inter-RAT measurement. The methods include a method of interrupting communication with a base station with which a UE is currently communicating for a certain period of time, measuring a signal of another frequency band, and maintaining the quality of a call that is currently set even when the communication is interrupted for a certain period of time. A method of increasing the transmission rate of data transmitted through a call for a certain period of time, and a method of maintaining the call even though the quality of the data is reduced by lowering the transmission rate of data transmitted through the call for a certain period of time. This is used.

The above-described method of measuring inter frequency and inter-RAT may be applied differently depending on whether the third generation mobile communication method uses frequency or time to distinguish uplink and downlink transmissions. In particular, when the uplink transmission and the downlink transmission are divided into time, the inter frequency measurement or the inter-RAT measurement is performed using a time zone during which the UE does not transmit / receive up / down.

FIG. 1A illustrates a frame structure in a narrowband time division duplexing multiple access method for applying an embodiment of the present invention, and FIG. 1B illustrates a structure of a first time slot period and a downlink transmission period in FIG. 1A. The drawing is shown.

First, referring to FIG. 1A, the frame 101 has a length of 10 ms (12800 chips according to 1.28 Mcps, which is a chip rate used in NB-TDD), and is composed of two subframes having a length of 5 ms. The two subframes constituting the frame 101 have the same structure. The subframe 102 includes seven timeslots, a downlink pilot time slot (DWPTS) 104, an uplink pilot time slot (UPPTS). 106) and a guard section (hereinafter referred to as GP) 105. Each time slot has a length of 864 chips and is used for uplink transmission from the UE to the base station (uplink, hereinafter referred to as "UL") or downlink transmission from the base station to the UE (downlink, hereinafter referred to as "DL"). For example, in the time slots constituting the subframe 102 of FIG. 1A, an upward arrow indicates a UL timeslot and a downward arrow indicates a DL timeslot. In addition, how many of the seven time slots constituting the one subframe 102 are used as DL timeslots and UL timeslots is set in the system by a ratio of uplink / downlink transmission data in the base station. In setting the up / down timeslots, the first time slot 103 (hereinafter referred to as “TS # 0”) 103 should always be used as a DL timeslot as a constraint, and the second timeslot (hereinafter referred to as “TS #”) may be used. 1 ") shall always be used as the UL timeslot. The DwPTS (96 chips) 104, the GP (96 chips) 105, and the UpPTS (160 chips) 106 exist between the TS # 0 and the TS # 1. The DwPTS 104 is used for initial cell search, synchronization, or channel estimation in a terminal, and the UpPTS 106 is used for uplink synchronization of a UE with a channel estimation at a base station. The GP 105 is a guard interval for removing interference caused by uplink transmission due to multipath delay between the DwPTS 104 and UPPTS 106 transmissions. In the NB-TDD system, a switching point is used for the uplink / downlink transmission, and two switching points exist in one subframe. The first switching point is fixed between the DwPTS 104 and UpPTS 106, and the second switching point is between TS # 1 to TS # 6 of FIG. 1 according to the ratio of up / down transmission data in the base station. Present at any location. The primary common control physical channel (hereinafter referred to as P-CCPCH ") 107 of FIG. 1 is located in TS # 0 and is transmitted using two codes. The code is referred to as NB. In the TDD communication system, the downlink channels using the same time slot are distinguished from each other, and the uplink transmission channels of the UEs using the same time slot are distinguished from each other. An orthogonal code having a length of 16 is used.

In FIG. 1B, the P-CCPCH 107, which is a physical channel for transmitting a broadcasting channel (hereinafter, referred to as a "BCH") containing system information of a base station, and a DwPCH used for synchronization of a base station by a UE The structure and location where it is sent are shown.

Referring to FIG. 1B, the P-CCPCH 107 includes a first data region 109, a midamble 110, a second data region 111, and a GP 112. The GP 112 is a 16-chip period present in the last portion of the time slot serves to remove the interference between the signals of the adjacent time slot. The DwPTS 104 is composed of a GP 113 and a Synchronization-DownLink (SYNC-DL) code 114. The GP 113 forms a GP having a length of 48 chip intervals with the GP 112 of the time slot Ts # 0, which is an interference caused by the multipath delay between the Ts # 0 and the DwPTS 104. It serves to remove. The reason why this interval is particularly long is that the sync-DL code 114 in the DwPTS 104 is the first signal when the UE comes into contact with the NB-TDD communication system and performs initial cell search through the sync-DL code. Because it synchronizes with the cell, it plays a very important role. Therefore, when interference occurs due to signals transmitted from the TS # 0, the influence on reception of the Sync-DL may be serious. Therefore, the GP 112 of the last part of the Ts # 0 and the GP 113 of the DwPTS 104 are combined to form a 48 chip section to ensure stable reception of a sync-DL code. The sync-DL code 114 has a total of 32 signals that the UE should first find. The UE correlates the 32 possible codewords with the signal of the largest intensity now being received to determine the sync-DL code and synchronizes with the cell to which it belongs.

FIG. 2A illustrates a frame structure in a GSM scheme for applying an embodiment of the present invention, and FIG. 2B illustrates a frequency correction channel (FCCH) and a shared channel (SCH) of frames in FIG. 2A. FIG. 2C illustrates a structure of a frame including a synchronization channel, and FIG. 2C illustrates a structure of a frequency correction channel (FCCH) and a shared channel (SCH) in FIG. 2B. 2A, 2B, and 2C are diagrams illustrating a frame structure, a frequency correction channel (FCCC), and a position of an SCH used in a GSM system. The FCCH and SCH are used to find synchronization of a frequency and a base station used in the GSM.

GSM is a representative asynchronous method of the second generation mobile communication system and uses the TDMA method. The multi-frame 201 shown in FIG. 2 is the largest radio transmission unit of GSM, and is composed of 51 frames, and the frame 202 is composed of eight time slots.

In GSM, the FCCH and the SCH are used for synchronization between the base station and the terminal in the measurement for initialization or handover. The FCCH is the first frame (frame # 0), eleventh frame (frame # 10), twenty first frame (frame # 20), thirty one of the 51 frames 203 constituting the multi-frame of FIG. The first frame is transmitted in the first frame (frame # 30) and the forty-first frame (frame # 40), and is transmitted in the first timeslot period 204 of the eight time slots constituting the frames.

In addition, the SCH is the second frame (frame # 1), the twelfth frame (frame # 11), twenty second frame (frame # 21), thirty two of the 51 frames 203 constituting the multi-frame The first frame is transmitted in the first frame (frame # 31) and forty second frame (frame # 41), and is transmitted in the first timeslot period 205 of the eight time slots constituting the frames.

3 is a diagram illustrating a situation in which inter-RAT measurement is required.                         

The UE 303 of FIG. 3 is assumed to be a UE capable of communicating in both the NB-TDD and the other system, and is assumed to exchange voice or packet signals with the NB-TDD base station 301. Assume you are moving to As described above, in case of a UE capable of supporting both systems, inter-RAT measurement is required for handover from the NB-TDD system to the GSM system.

The UE 303 communicating with the NB-TDD base station 301 of FIG. 3 moves to the GSM base station 302, and receives an Inter-RAT measurement signal command from the NB-TDD base station 301. The signal of the GSM base station 302 is measured. The signal of the GSM base station 302 may be signals such as the FCCH and SCH or the transmission channel shown in FIGS. 2A, 2B and 2C. When the NB-TDD base station 301 instructs the UE 303 to inter-RAT measurement, signals of other GSM base stations in the frequency band used by the NB-TDD base station 301 are used. After reporting on the measurement results, the measurement results determine that the signal strength is insufficient for the UE 303 to handover or the signal strength between the UE 303 and the NB-TDD base station 301 is gradually increased. If it is determined that the weakness may be.

The UE 303 of FIG. 3 acquires base station synchronization and base station information of the GSM base station 302 through signal measurement of the GSM base station 302, and then transmits the measurement result to the base station 301 and the NB. -Handover to the GSM base station 302 according to the command of the TDD base station 301 to continue the communication. 3 illustrates a case where a UE establishes a call with a base station and receives an inter-RAT measurement command through the call, and transmits through a P-CCPCH of the base station in a situation where a call between the UE and the base station is not established. The UE may perform the inter-RAT measurement using information necessary for the inter-RAT measurement among the system information of the BCH.

FIG. 4 is a diagram illustrating time slots capable of inter-RAT measurement in a current NB-TDD system when there is a UE supporting NB-TDD and other mobile communication schemes in the situation described with reference to FIG. 3.

4 shows an i-th subframe between the UE and the base station. In the i-th subframe 401, the UE transmits an uplink in a time slot 403 and a downlink reception in a time slot 404. do. The UE may measure Inter-RAT signals in time slots other than the time slot 403 and time slot 404. In FIG. 4, intervals 405, 406, 407, and 408 become positions where the UE can measure an inter RAT signal.

Of the intervals in which the UE can measure the inter-RAT signal, a Radio Frequency Transition Time for the UE to transfer its transmit / receive frequency to a band in which the inter-RAT signal is transmitted and received, and the UE The interval excluding the radio frequency switching time back to the frequency band is the interval in which the UE can actually perform inter-RAT measurement (hereinafter, referred to as a "measurable interval" for convenience of description). The measurable section is a section excluding the radio frequency change time in the sections 405, 406, 407, and 408 of FIG. 4. The longer the UE can measure, the longer the measurement of the inter-RAT signal can be facilitated and the reliability of the measurement result can be increased. In the prior art illustrated in FIG. 4, the length of the UE-measurable interval is determined according to positions of an uplink transmission time slot and a downlink transmission time slot of the UE, and the uplink transmission time slot and the downlink transmission time slot The measurable section may be longer or the measurable section may be smaller depending on the position of. In FIG. 4, when the interval in which the UE actually measures the inter-RAT signal is longer, there is no problem in the measurement of the UE, but in the short case, the UE may not properly measure the Inter-RAT signal.

Table 1 below summarizes the time required for checking the FCCH and SCH according to the radio frequency conversion length of the UE when TS1 and TS5 of FIG. 1A are allocated to the UE. In this case, it can be seen that the UE having a radio frequency conversion time of 0.8 ms or more cannot inspect the FCCH and the SCH.

As another example, Table 2 summarizes the average FCCH and SCH check times according to radio frequency change time for UEs to which TS1 and TS4 are allocated. It can be seen that the UE having a radio frequency change time of 0.9 ms or more cannot inspect the FCCH and the SCH at all.

As can be seen from the examples of Table 1 and Table 2, a situation may occur in which the UE cannot inspect the FCCH and the SCH at all according to the radio frequency change time and the allocated slot of the UE. However, the current UTRAN commanding the inter-RAT measurement does not have any information about the radio frequency change time of the UE, so if the inter-RAT measurement command is not received from the UE, the cause cannot be determined and the countermeasures are taken. It can be seen that the situation can not be determined.

Looking at the situation in more detail as follows. 8 shows the flow of messages expected when the NB-TDD base station commands the measurement of the GSM base station signal in the current standard. Referring to FIG. 8, in step 801, the NB-TDD base station instructs the UE to inter-RAT measurement for neighboring GSM cells. In this case, the NB-TDD base station informs a base transceiver station identity code (hereinafter referred to as "BSIC") and an ARBSN (Absolute Radio Frequency Channel Number) of the corresponding cell with respect to neighboring GSM cells. At the same time, it determines how to report the measurement and whether the BSCI needs confirmation when reporting the measurement and informs the UE. The measurement method may include a method of reporting a measurement when an event occurs and a method of reporting a measurement periodically.

With the above information, the UE commanded to measure the GSM cell evaluates whether the measurement can be performed. If the UE can perform the commanded measurement, the UE performs the measurement and then transmits the measurement to the UTRAN in step 802. report. However, if the UE cannot perform the commanded measurement, the MEASUREMENT CONTROL FAILURE message is transmitted to the UTRAN by adding the cause of the measurement failure as shown in step 803.

The causes of measurement failure added to step 803 include unsupported measurement and configuration incomplete. The unsupported measurement is a value attached to the MEASUREMENT CONTROL FAILURE message when the base station commands a measurement that the terminal does not support, and the configuration incomplete requires the Inter-RAT measurement command message to change the measurement that was previously performed, but the corresponding measurement If this is not being performed or if a section that interrupts the communication necessary for inter-RAT measurement is already used for another measurement, it is the cause of failure included in the measurement command failure message.

In step 802, the UE performs the actual measurement to report the measurement whether the BSIC requires confirmation and whether the method of reporting the inter-RAT measurement result is periodic or event-triggered mode. Can be classified according to

For convenience of explanation, the operation of the UE commanded for inter-RAT measurement requiring situational reporting and confirmation of BSIC is assumed. The UE measures the received signal strength of the GSM cell during the slot capable of inter-RAT measurement described with reference to FIG. 4 based on the neighbor GSM cell information (BSIC and corresponding ARFCN) provided together in the inter-RAT measurement command. In this case, the channel used to measure the strength of the received signal has no special constraint, and only the reception strength of any channel of the corresponding GSM cell needs to be measured during the measurable slot. The received signal strengths of all neighboring GSM cells are measured, listed in descending order, and then the FCCH and SCH of the cell with the strongest received signal are examined. Through this, the UE can check the BSIC of the cell. Upon successful verification of the BSIC, the UE checks whether the NB-TDD base station conforms to the situation presented at the time of ordering the inter-RAT measurement and if so, reports the measurement with the confirmed BSIC.

Subsequently, the UE next checks the FCCH and SCH for the cell with the strongest received signal and checks the BSIC. In addition, if the BSIC check is successful, it is also compared with the situation given when receiving the Inter-RAT measurement command, and if the situation is met, the measurement is also reported. These reports can be made one at a time, or can be reported simultaneously for all cells that satisfy the situation.

While repeating this process, the BSIC compares and reports the identified cells with respect to the identified cells. Some of the cells with strong signal strength are kept in sync through the FCCH and SCH tests. This is to minimize the time required for synchronization when the NB-TDD base station commands a handover to a specific GSM cell. In the case of this type of inter-RAT measurement command, the cells satisfying the condition but are excluded from the report if the BSIC is not confirmed. That is, as described above, the process of measuring the received signal strength of all neighboring GSM cells is performed only for the cell that has been confirmed by the BSIC. Therefore, when there is insufficient time for reading the BSIC through the signal transmitted from the SCH of all the neighboring GSM cells, the UE does not recognize the BSIC, and the UTRAN also caused this situation due to the short measuring interval of the UE. It is not possible to distinguish whether or not there is a GSM cell that satisfies a given situation condition. Because of this, the UE cannot eventually perform handover, and the UTRAN fails to perform normal handover and causes a malfunction.

If the inter-RAT measurement command is a periodic report and is given in a form requiring BSIC verification, even if the cell is not BSIC confirmed, only the strength of the received signal can be reported together with the ARFCN of the cell. In addition, when performing the inter-RAT measurement command of the type that does not require the BSIC confirmation, it can be reported only considering the strength of the received signal.

As a possible problem in the Inter-RAT measurement scenario, if the NB-TDD base station commands the measurement of the received signal strength of the GSM cell, and informs the UE of the BSIC of the cell and the situational determination of the report form of the measurement, the table is generated. As shown in Table 1 and Table 2, it is possible that the UE cannot identify the BSIC at all according to the type of slot allocated to the UE and the radio frequency change time. That is, the UE can fully check the received signal strength of each GSM cell, but may not be able to report the corresponding measurement because the BSIC cannot be confirmed. In this case, the base station commanding the inter-RAT measurement does not receive any measurement from the UE, but this situation indicates that the received signal strength of the GSM cell measured by the UE does not meet the situation condition suggested by the base station, or Intensity does not distinguish whether a situation satisfies a given situation but does not identify a BSIC.

Accordingly, an object of the present invention for solving the above problems is to provide a method for supporting handover from a mobile communication system using a narrowband time division duplexing scheme to a mobile communication system using another scheme.

Another object of the present invention is to provide a method for measuring a received signal for handover from a mobile communication system using a narrowband time division duplexing scheme to a mobile communication system using another scheme.

Another object of the present invention is to provide a method for ensuring synchronization for handover from a mobile communication system using a narrowband time division duplexing scheme to a mobile communication system using another scheme.

Another object of the present invention is to receive the service from the mobile communication system supporting the NB-TDD method Inter in the interval that the mobile terminal does not transmit and receive up / down to handover to the mobile communication system supporting the GSM method To provide a method for performing RAT measurements.

In a first aspect for achieving the above object, the present invention provides a communication between the first base station, at least one second base station serving a different communication method from the first base station, and the first base station. In the mobile communication system comprising a mobile terminal for moving to a handover area where the area occupied by the first base station and the area occupied by the second base station overlaps with each other. A method for measuring the strength of a received signal from the second base station in a measurement interval in which no communication is performed and checking base station identification verification information corresponding thereto and reporting the same to the first base station, the method comprising: The first base station measures the strength of the received signal of the first base station and checks and reports corresponding base station identification verification information. Receiving a measurement control message from the second base station in the measurement section, and identifying the base station of the second base station in which the measured received signal strength satisfies a predetermined threshold condition. Verifying the verification information, and when the base station identification verification information is confirmed in the measurement section, reporting the confirmed base station identification verification information together with the received signal strength information to the first base station, and verifying the base station identification in the measurement section. If the information is not confirmed, a process of reporting only the received signal strength information to the first base station, and if a new time slot is allocated from the first base station because only the received signal strength information is reported for a predetermined time, the newly assigned Adjusting the measurement interval by the received time slot It characterized in that it comprises.

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In the second aspect for achieving the object as described above, the present invention in the second aspect for achieving the object as described above, the present invention provides a communication method that is different from the first base station, and the first base station. The mobile station moves to a handover area in which the area occupied by the first base station and the area occupied by the second base station overlap with each other at least one serving base station and the first base station. And a terminal, wherein the mobile terminal checks the strength of the received signal from the second base station and corresponding base station identification verification information in a measurement section in which communication with the first base station is not made. In step 1, the first base station determines the mobile station based on the received signal strength information reported from the mobile station and corresponding base station identification verification information. A method for allocating new time slots, the method comprising: measuring a strength of a received signal from the second base station, transmitting a measurement control message to the mobile station to confirm and report corresponding base station identification verification information; If only the received signal strength information that does not include the base station identification verification information is reported for a predetermined time in response to the measurement control message, the mobile terminal is allocated by newly assigning a forward time slot and a reverse time slot for adjusting the measurement interval. It characterized in that it comprises a process of transmitting to.
In a third aspect to achieve the above object, the present invention provides a communication between the first base station, at least one second base station serving a different communication method from the first base station, and the first base station. In the mobile communication system comprising a mobile terminal for moving to a handover area where the area occupied by the first base station and the area occupied by the second base station overlaps with each other. A method for measuring the strength of a received signal from the second base station in a measurement interval in which no communication is performed and checking base station identification verification information corresponding thereto and reporting the same to the first base station, the method comprising: The first base station measures the strength of the received signal of the first base station and checks and reports corresponding base station identification verification information. Receiving a measurement control message from the second base station in the measurement section, and identifying the base station of the second base station in which the measured received signal strength satisfies a predetermined threshold condition. Confirming the verification information and receiving signal strengths satisfying the predetermined threshold condition in the measurement section, and if the corresponding base station identification verification information is not confirmed, cause of measurement failure indicating that the measurement section is insufficient. Transmitting a first forward time slot and a reverse time slot from the first base station in response to the transmission to the first base station and corresponding to the cause of the measurement failure, adjusting the measurement interval by the forward time slot and the reverse time slot; Characterized by including the process.
In a fourth aspect for achieving the above object, the present invention provides a communication between the first base station, at least one second base station serving a different communication method from the first base station, and the first base station. In the mobile communication system comprising a mobile terminal for moving to the handover area overlapping the area occupied by the first base station and the area occupied by the second base station during the execution, the mobile terminal from the second base station A method of determining a measurement interval required for measuring the strength of a received signal of the base station and verifying corresponding base station identification verification information, the method comprising: measuring the strength of the received signal by a request from the first base station; Reporting, to the first base station, the capability of confirming corresponding base station identification verification information; and reporting from the first base station. By a forward time slots and backward time slots is newly allocated in consideration of the capacity is characterized in that it comprises the step of adjusting the measurement period.
In a fifth aspect for achieving the above object, the present invention includes a base station and a mobile station in an area occupied by the base station, wherein each of the consecutive subframes has a plurality of time slots, each In the narrowband time division communication system, wherein the time slots in the subframe are allocated to at least one forward time slot and at least one uplink time slot for one mobile station, the area using the narrowband time division communication system and GSM Received signal strengths in specific frequency regions for handover from GSM base stations in the regions using the GSM communication system are predetermined by the mobile terminal moving to a handover region where the regions using the communication system overlap. Received signal strength information satisfying a condition and the predetermined pair A method for transmitting, by the mobile station, base station identification verification information for identifying GSM base stations using the specific frequency bands for received signal strengths satisfying a value of the received signal strengths, the received signal strengths satisfying the predetermined condition Receiving from the base station a measurement control message for reporting information and the base station identification verification information identifying the GSM base stations using the specific frequency bands for received signal strengths that satisfy the predetermined condition; The base station identification verification information is measured and reported to the base station by receiving received signal strength information for the specific frequency bands regardless of verification when searching in the measurement interval between the time slots in each subframe allocated to the mobile station. Process and pre-determined poems While if the received signal strength information only and reported as a new time slot from the first base station assigned because, it characterized in that it comprises the step of adjusting the measurement period by the newly assigned time slots.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

DETAILED DESCRIPTION In the following detailed description, one representative embodiment of the present invention is set forth in order to achieve the above technical problem. And other embodiments that can be presented with the present invention are replaced by the description in the configuration of the present invention.

There are five ways to solve the problem proposed by the present invention as follows.                     

That is, in the process of performing inter-RAT measurement for handover to GSM in a narrowband time division communication system, a method for solving a problem due to lack of measurement time at idle time in the situation described in the related art. As shown in the following five embodiments.

(1) Embodiment 1: When defining a short time of measurement time in Idle Time in Inter-RAT measurement as Short Idle Time, the measurement failure cause as described above in the case of Short Idle Time This can be solved by adding a new value and adding a process that allows you to perform different actions accordingly.

(2) Embodiment 2: In the inter-RAT measurement, when reporting the UE capability to determine the UE capability before transmitting a measurement control message for the UTRAN to perform the measurement to the UE to perform the handover By adding and reporting a new information element (hereinafter referred to as IE) related to radio frequency change time, the UTRAN can solve the problem by adding a process for allocating a new slot by recognizing that the UE is short of measurement time. .

(3) Embodiment 3: In the process of receiving the periodic measurement report from the UE by the UTRAN in inter-RAT measurement, the UTRAN periodically reports GSM RSSI (Received Signal Strength Indicator) as a measurement report for a predetermined time. When the measurement report message is reported for the predetermined time without the BSIC because the BSIC is not recognized for the predetermined time, the UTRAN recognizes that the UE is insufficient of the measurement time, and reassigns the slot accordingly. This can be solved by adding

(4) Embodiment 4: In Inter-RAT measurement, the UE can solve the allocation of slots that may cause a shortage of measurement time by the UTRAN in advance.

(5) Embodiment 5: In case of allocation of slots in which UE may cause insufficient measurement time in inter-RAT measurement, regardless of initial allocation, handover from base station to GSM in narrowband time division communication system Only by performing the measurement of the situation can be solved by excluding the allocation of slots that can cause the lack of the measurement time.

(6) Embodiment 6: The base station requires the UE to inter-RAT measurement in the form of situational and BSIC check required, and the BSIC can check the BSIC due to the lack of time for the UE to read the BSIC of all neighboring GSM cells. If not, the UE and the UTRAN can be resolved to perform normal handover by adding a process of reporting the Absolute Radio Frequency Channel Number (ARFCN), which is information on reception strength measurements and frequencies of all neighboring GSM cells.

First, look at the process of Example 1 of the present invention.

In the first embodiment of the present invention, when defining a short time of measurement time in Idle Time in Inter-RAT measurement as Short Idle Time, the measurement failure cause is described in the case of Short Idle Time as described above. We'll look at how to solve this problem by adding a new value and adding a process that allows you to perform different actions.

5 illustrates a process of resolving a measurement failure due to lack of a measurable interval when a new failure cause is added according to the first embodiment of the present invention.

First, in step 501, a UE communicating with a base station of a narrowband time division communication system receives a measurement control message from a UTRAN in a Cell_DCH state. In step 501, the measurement control message may be received in the case of inter-RAT, intra-frequency, inter-frequency, traffic volume measurement, etc. In this case, the case is received in the case of inter-RAT. It is assumed that a UE communicating with a base station of a time division communication system hands over to GSM. In step 501, the UE receives BSIC, which is up to 32 base station identifier codes and information about frequency, and ARFCN, which is information about a GSM cell, that is, information on a neighbor cell list, from the UTRAN. The UE receives information including information on whether to periodically perform measurement or according to an event occurrence. This means that the UTRAN gives the UE a measurement command for Inter-RAT. That is, the UE that receives the measurement control message in step 501, as described above, if the Inter-RAT measurement report method is a periodic report or a situation occurrence report but does not need BSIC verification, the UE measures the neighboring GSM cells. Report the measurement to UTRAN. However, if the inter-RAT measurement report method is situational and requires confirmation of the BSIC, the UE reviews the measurable interval considering the radio frequency change time of the UE and then determines whether it can be measured.

If the BSIC cannot be confirmed, that is, if the measurement time is insufficient, the UE transmits a measurement control failure message to the UTRAN including a failure cause indicating that the BSIC cannot be confirmed due to insufficient measurement interval (step 502). In step 502, when the BSIC check is impossible, that is, when the radio frequency change time is 0.8 ms or more and TS1 and TS5 or TS2 and TS6 are allocated to the UE, or when the radio frequency change time is 0.9 ms or more, Measurement control failure message including failure cause that BSIC cannot be confirmed due to lack of measurement time for inter-RAT because TS4, TS2 and TS5 or TS3 and TS6 are allocated to the UE because BSIC is impossible. Is to request reallocation of slot by sending to UTRAN. A method of transmitting the cause of the measurement failure by attaching it to the measurement control failure message in step 502 will now be described in more detail.

The cause of the measurement failure is a value attached to and transmitted in a measurement control failure message. The values defined so far include unsupported measurement and configuration incomplete. unsupported measurement is a value attached to the measurement control failure message when the base station commands a measurement that is not supported by the terminal, and configuration incomplete requires that the Inter-RAT measurement command message change the measurement that was previously performed, but the measurement is performed. If not, or if the interval to stop the communication necessary for Inter-RAT measurement is already used for other measurement, it is the cause of failure included in the measurement command failure message. Subsequently, the UTRAN receiving the measurement report failure message indicating that the BSIC cannot be confirmed due to lack of the measurable interval changes the slot allocated to the UE to inform the UE of the BSIC in step 503. That is, the slot is changed and allocated to the UE to inform the UE. In this case, messages such as PHYSICAL CHANNEL RECONFIGURATION, TRANSPORT CHANNEL RECONFIGURATION, RADIO BEARER SETUP, RADIO BEARER RECONFIGURATION messages, etc. may be used. In step 503, the UE changes to a changed allocation slot, and the UTRAN may request the UE to inter-RAT measurement again using the changed slot (step 504).

The present invention proposes the addition of a cause of failure, which means that the measurement command cannot be performed due to a lack of a measurable section other than the cause of failure. In addition, the base station received the cause of the failure proposes to change the slot assigned to the UE to give the inter-RAT measurement command again.

Second, look at the process of Example 2 of the present invention.

In Embodiment 2 of the present invention, in the inter-RAT measurement, the UE capability is reported in order to determine UE capability before transmitting a measurement control message for the UTRAN to perform measurement to the UE to perform handover. By adding and reporting a new information element (hereinafter referred to as IE) related to radio frequency change time, the UTRAN recognizes that the UE is short of measurement time and adds a process of allocating a new slot. Take a look at

FIG. 6 illustrates a process in which a measurement failure due to lack of a measurable interval is resolved by notifying a base station of information on a radio frequency change time when reporting a capability of a UE according to a second embodiment of the present invention.

First, in step 601, the UTRAN transmits a UE CAPABILITY ENQUIRY message for requesting the UE to report its capability in advance in order to solve the above-described problems before making a measurement request of the GSM cell in advance. Upon receiving the UE CAPABILITY ENQUIRY message, the UE transmits information on the radio frequency change time with the UE CAPABILITY INFORMATION message in step 602. Upon receiving the information about the radio frequency change time of the UE in step 602, the UTRAN determines whether a slot type allocated to the UE is suitable for identifying the BSIC. That is, when the radio frequency change time is 0.8 ms or more and TS1 and TS5 or TS2 and TS6 are allocated to the UE, or when the radio frequency change time is 0.9 ms or more and TS1 and TS4, TS2 and TS5 or TS3 and TS6 are the UE. Is assigned to the UE, the UTRAN recognizes that the UE is unable to confirm the BSIC and determines a change of slot. When the UE reports its capability to the base station, the message used is the UE CAPABILITY INFORMATION.

The UE CAPABILITY INFORMATION message is transmitted when the UE CAPABILITY ENQUIRY message is received from the base station or when the value of the UE_CAPABILITY_TRANSFFERRED variable stored in the UE is changed. Accordingly, in step 603, the UTRAN reassigns a slot.

601 Possible messages include PHYSICAL CHANNEL RECONFIGURATION, TRANSPORT CHANNEL RECONFIGURATION, RADIO BEARER SETUP, and RADIO BEARER RECONFIGURATION. If the radio frequency change time of the UE and the pre-allocated slots are sufficient to confirm the BSIC, step 603 may be omitted. In step 604, the base station may instruct the UE to inter-RAT measurement.

Third, look at the process of Example 3 of the present invention.

In the third embodiment of the present invention, in the process of receiving the periodic measurement report from the UE by the UTRAN in inter-RAT measurement, the UTRAN periodically reports GSM RSSI (Received Signal Strength) as a measurement report for a predetermined time. If the measurement report message is reported for the predetermined time without the BSIC because the BSIC is not recognized for a certain time, the UTRAN recognizes that the UE is short of the measurement time and reassigns the slot accordingly. Let's take a look at how to solve it by adding.

FIG. 7 illustrates a process of solving the BSIC due to a lack of a measurable interval by adding a limiting factor to the inter-RAT measurement command method according to the third embodiment of the present invention.

As described above, there are two ways to report the measurement when issuing a GSM-related Inter-RAT measurement command. This includes reporting the measurements periodically and reporting them periodically. If the UTRAN requires confirmation of the BSIC at the time of the Inter-RAT measurement command, there is a slight difference in how the UE reports the measurements using the two reporting methods. That is, if the measurement needs to be periodically reported, the UE may simply report the BCCH ARFCN value and the corresponding measurement even if the BSIC is not confirmed. The BCCH ARFCN value is a value given at the time of an inter-RAT measurement command and means a frequency value to be used for measurement. However, if the measurement report is a situational occurrence, even if the strength of the received signal satisfies the given situation, it cannot be reported unless the BSIC is confirmed.

Therefore, in step 701, when the UTRAN issues an inter-RAT measurement command in consideration of the above situation, the UTRAN always orders to perform periodic measurement report first. That is, in order to solve the problems of the prior art, the UE performing inter-RAT measurement from the base station of the narrowband time division communication system to the GSM first reports the periodic measurement. In step 702, the UE, which has been requested to report the periodic measurement of the inter-RAT measurement, periodically makes a measurement report to the UTRAN. In this case, the UTRAN receives a measurement report from the UE for a predetermined time, and if the UE does not report the BSIC, the UTRAN knows that the UE does not recognize the BSIC due to the lack of a measurable interval, and reassigns the slot. You will be judged. In step 702, the UE reports a measurement value and a corresponding BCCH ARFCN value when the BSIC cannot be identified due to a lack of a measurable interval.                     

In order to change the length of the measurable interval, that is, the UTRAN determines a change of a slot previously allocated to the UE and notifies the UE of the change in step 703. At this time, available messages include PHYSICAL CHANNEL RECONFIGURATION, TRANSPORT CHANNEL RECONFIGURATION, RADIO BEARER SETUP, and RADIO BEARER RECONFIGURATION. In step 703, the UTRAN newly assigning a slot to the UE may request the UE to report inter-RAT measurements in a situation 704.

Fourthly look at the process of Example 4 of the present invention.

Embodiment 4 of the present invention looks at a solution for causing the UTRAN to previously limit the allocation of slots that can cause the UE to run out of measurement time in inter-RAT measurement, that is, not able to identify the BSIC.

This method limits the combination of slots that may cause problems due to lack of measurable interval when allocating forward and reverse slots to the UE. That is, the slots are not allocated in a combination of TS1, TS5, TS2, TS6, TS1, TS4, TS2, TS5, TS3, TS6, and the like. This allows the UTRAN to pre-manage the combination of timeslots described above, so that such timeslots may cause problems with GSM inter-RAT measurement regardless of initial or reassignment, i.e. identify the BSIC. It is essentially eliminating timeslot assignments in unknown situations. Therefore, the limitation of this method is to limit the degree of freedom in slot allocation by simply limiting the combination of slots without considering the radio frequency change time of a particular UE. However, there is an advantage that no transmission of information from the UE is required.                     

Fifth, the process of Example 5 is as follows.

In Embodiment 5 of the present invention, in case of allocation of slots that may cause the UE to run out of measurement time in inter-RAT measurement, regardless of initial allocation, handover from base station to GSM in a narrowband time division communication system is performed. It looks at how to solve the problem by excluding the allocation of slots that can cause the lack of the measurement time only when the measurement of the situation.

This method uses a combination of slots (ie TS1 and TS5, TS2 and TS6, TS1 and TS4, TS2 and TS5, TS3, TS6, etc.) that may not be able to identify the BSIC due to the lack of the measurable interval during initial channel allocation. The BSIC can be checked only when receiving a measurement request from the UTRAN when the UE communicating with the base station of the narrowband time division communication system moves to the GSM base station after allocating a slot regardless of the combination). In the case of a UE allocated to a channel by a combination of no slots, this means a method of reallocating a slot in a form in which a measurable interval may increase, that is, in a form in which a BSIC may be identified.

Finally, the process of Example 6 is as follows.

In the sixth embodiment of the present invention, if the UTRAN requires confirmation of the BSIC and situational reporting in the form of a report on inter-RAT measurement, the measurement can be reported using the corresponding ARFCN instead of the BSIC even if the UE fails to confirm the BSIC. This is how you do it. That is, in the past, when the identification of the BSIC is not possible, the UE could not perform a procedure for measurement report. However, the embodiment of the present invention allows the UE to perform the measurement report process even if it is impossible to check the BSIC. An embodiment of the present invention will be described in detail as follows. An embodiment of the present invention will be described with reference to FIG. 9.

FIG. 9 illustrates a process for allowing a UE that does not recognize a BSIC to perform a measurement report during inter-RAT handover according to the sixth embodiment of the present invention.

First, in step 901, a base station of a narrowband time division communication system requests an Inter-RAT measurement from a UE that is in communication with the base station in a form requiring situational reporting and confirmation of BSIC. The UE receiving the inter-RAT measurement determines whether the BSIC can be identified based on the slot and radio frequency change time allocated to the UE. In other words, if the BSIC can be identified, the BSIC can be checked first as in the conventional method, and then the strength of the received signals of all the GSM cells can be measured only in the cell in which the BSIC is confirmed. However, if it is determined that the BSIC cannot be identified (i.e., the radio frequency change time is 0.8 ms or more and TS1 and TS5 or TS2 and TS6 are allocated to the UE, or the radio frequency change time is 0.9 ms or more and TS1 and TS4 , When TS2 and TS5 or TS3 and TS6 are allocated to the UE), the UE may measure the received signal even for a cell for which the BSIC is not confirmed. As described above, if the identification of the BSIC becomes impossible, the UE reports to the UTRAN including the reception strength of the ARFCN and all or the corresponding GSM cells in step 902. In contrast, if the BSIC can be confirmed, the UE in step 902. Report to the UTRAN, including the received BSICs and the reception strengths of all nearby or GSM cells. That is, the UE may report the received strength measurement values of the BSIC and the corresponding cell if the BSIC can be identified, and, if the BSIC cannot be determined, the ARFCN and the received strength measurement values of the corresponding cell are reported together to the UTRAN. In step 902, when the UTRAN receives a report from the UE for a predetermined time and reports only ARFCN because the UE fails to check the BSIC, the UTRAN reports that the UE is a SCH from the corresponding GSM cell. It is determined that the BSIC cannot be confirmed due to the lack of a section for identifying the BSIC from the signal. That is, in step 902, the UTRAN that receives the measurement report from the UE determines whether the BSIC corresponding to the measurement is included, and if the BSIC is not included in the measurement report for a certain period, the UTRAN decides to change the slot allocated to the UE. will be. The UTRAN that determines the change of the slot for the UE informs the UE of the information about the changed slot in step 903. At this time, as the usable message, a 'PHYSICAL CHANNEL RECONFIGURATION', a 'TRANSPORT CHANNEL RECONFIGURATION' message, etc. may be used, all of which include information on the changed slot. The UE, which has received the information about the changed slot in operation 903, operates through the newly changed slot from a predetermined time.

In any of the six methods, the problem of failing to check the BSIC due to the lack of the measurable interval may be solved.

As described above, the present invention can measure the received signal strength of the GSM cell due to the lack of the measurable interval, but it is not possible to check the BSIC, so that the UE does not report the measurement and if the UTRAN does not receive the measurement report, the cause analysis and Effectively solve problems that fail to determine countermeasures.

Claims (27)

Communicating with the first base station, at least one second base station serving a different communication method from the first base station, and an area occupied by the first base station during the communication with the first base station and the second base station. In a mobile communication system comprising a mobile terminal moving to a handover area overlapped by the area occupied by the mobile station, the mobile terminal is connected to the received signal from the second base station in a measurement section in which communication with the first base station is not performed. In the measuring method for the handover to measure the strength of the base station identification verification information corresponding to the base station identification verification information to the first base station, Receiving a measurement control message from the first base station to measure the strength of the received signal from the second base station and to confirm and report the corresponding base station identification verification information; Receiving the measurement control message, measuring the received signal strength from the second base station in the measurement section, and confirming base station identification verification information of the second base station where the measured received signal strength satisfies a predetermined threshold condition; Process, When the base station identification verification information is confirmed in the measurement section, the confirmed base station identification verification information is reported along with the received signal strength information to the first base station, and when the base station identification verification information is not confirmed in the measurement section, the received signal Reporting only strength information to the first base station; If a new time slot is allocated from the first base station because only the received signal strength information is reported for a predetermined time, measuring the measurement interval according to the newly allocated time slot, the measurement method for handover . delete The method of claim 1, And information about the new time slot is transmitted from the first base station to the mobile terminal through a physical channel reassignment message. The method of claim 1, And the information about the new time slot is transmitted from the first base station to the mobile terminal through a transport channel reassignment message. The method of claim 1, The narrowband time division scheme is supported by the first base station, and the Global System for Mobile Communications (GSM) scheme is supported by the second base station. The method of claim 5, The measurement interval is determined by the interval between at least one forward time slot and at least one reverse time slot of the plurality of time slots constituting one sub-frame. The method of claim 1, And transmitting the radio frequency channel number (ARFCN) information together with the received signal strength information if the base station identification verification information is not confirmed in the measurement section. Communicating with the first base station, at least one second base station serving a different communication method from the first base station, and an area occupied by the first base station during the communication with the first base station and the second base station. And a mobile terminal for moving to an overlapping handover area, wherein the mobile terminal has a strength of a received signal from the second base station in a measurement section in which communication with the first base station is not made; In the mobile communication system for confirming the corresponding base station identification verification information, the first base station determines the time slots for the mobile terminal by the received signal strength information reported from the mobile terminal and corresponding base station identification verification information. In the measurement method for newly allocated handover, Measuring a strength of the received signal from the second base station and transmitting a measurement control message to the mobile station to confirm and report base station identification verification information corresponding thereto; If only the received signal strength information that does not include the base station identification verification information is reported for a predetermined time in response to the measurement control message, a process of newly allocating a time slot for adjusting the measurement interval and transmitting the newly determined time slot to the mobile terminal; Measurement method for handover comprising. The method of claim 8, The information about the new time slot is transmitted to the mobile station through a physical channel reassignment message. The method of claim 8, And the information about the new time slot is transmitted to the mobile station through a transport channel reassignment message. The method of claim 8, The narrowband time division scheme is supported by the first base station, and the Global System for Mobile Communications (GSM) scheme is supported by the second base station. The method of claim 11, The measurement interval is determined by the interval between at least one forward time slot and at least one reverse time slot of the plurality of time slots constituting one sub-frame. Communicating with the first base station, at least one second base station serving a different communication method from the first base station, and an area occupied by the first base station during the communication with the first base station and the second base station. In a mobile communication system comprising a mobile terminal moving to a handover area overlapped by the area occupied by the mobile station, the mobile terminal is connected to the received signal from the second base station in a measurement section in which communication with the first base station is not performed. In the measuring method for the handover to measure the strength of the base station identification verification information corresponding to the base station identification verification information to the first base station, Receiving a measurement control message from the first base station to measure the strength of the received signal from the second base station and to confirm and report the corresponding base station identification verification information; Receiving the measurement control message, measuring received signal strength from the second base station in the measurement section, and checking base station identification verification information of the second base station whose measured received signal strength satisfies a predetermined threshold condition; and, Receiving a signal intensity that satisfies the predetermined threshold condition in the measurement section, but if the corresponding base station identification verification information is not confirmed, transmitting a cause of measurement failure indicating that the measurement section is insufficient to the first base station; , And if the new time slot is allocated from the first base station in response to the cause of the measurement failure, adjusting the measurement interval by the time slot. The method of claim 13, And the information about the new time slot is transmitted through a physical channel reassignment message. The method of claim 13, And the information about the new time slot is transmitted through a transport channel reassignment message. The method of claim 13, The narrowband time division scheme is supported by the first base station, and the Global System for Mobile Communications (GSM) scheme is supported by the second base station. The method of claim 16, The measurement interval is determined by the interval between at least one forward time slot and at least one reverse time slot of the plurality of time slots constituting one sub-frame. Communicating with the first base station, at least one second base station serving a different communication method from the first base station, and an area occupied by the first base station during the communication with the first base station and the second base station. In a mobile communication system including a mobile terminal moving to a handover area overlapped by the area occupied by the mobile station, the mobile terminal measures the strength of the received signal from the second base station, and corresponding base station identification verification information In the measurement method for handover to determine the measurement interval required to confirm, It is possible to receive the capability report request from the first base station, determine whether it is possible to measure the strength of the received signal in the currently set measurement interval in response to the capability report request, and the terminal capability information corresponding to the determination result. Reporting to the first base station; And adjusting the currently set measurement interval by a newly allocated time slot in view of the terminal capability information from the first base station. The method of claim 18, And the terminal capability information includes at least relevant information on radio frequency variation time. The method of claim 18, And the information about the new time slot is transmitted through one of a physical channel reassignment message and a transport channel reassignment message. The method of claim 18, The narrowband time division scheme is supported by the first base station, and the Global System for Mobile Communications (GSM) scheme is supported by the second base station. The method of claim 21, The measurement interval is determined by the interval between at least one forward time slot and at least one reverse time slot of the plurality of time slots constituting one sub-frame. A mobile station in a region occupied by the base station and the base station, wherein each of the consecutive subframes has a plurality of time slots, wherein the time slots in each subframe are at least one forward time for one mobile station; In a narrowband time division communication system allocated to a slot and at least one reverse time slot, the area using the narrowband time division communication system overlaps with the area using a Global System for Mobile Communications (GSM) communication system. Received signal strength information for which received signal strengths in specific frequency regions for handover from GSM base stations in regions using the GSM communication system by the mobile terminal moving to a handover region satisfy a predetermined condition And three received signals satisfying the predetermined condition. In the particular frequency band used by the identified base station to identify the GSM base station the verification information for a measurement method for a handover of the mobile station is transmitted to the base stations, Measurement control to report the received signal strength information satisfying the predetermined condition and the base station identification verification information identifying the GSM base stations using the specific frequency bands for the received signal strength satisfying the predetermined condition Receiving a message from the base station; The base station identification verification information is measured and reported to the base station by receiving received signal strength information for the specific frequency bands regardless of verification when searching in the measurement interval between the time slots in each subframe allocated to the mobile station. Process, And adjusting a measurement interval by the newly allocated time slot when a new time slot is allocated from the base station because only the received signal strength information is reported for a predetermined time. delete The method of claim 23, wherein And information about the new time slot is transmitted from the base station to the mobile station through a physical channel reassignment message. The method of claim 23, wherein And information about the new time slot is transmitted from the base station to the mobile station through a transport channel reassignment message. Inter-RAT communication between mobile communication systems using different communication methods in a predetermined measurable period for handover as the mobile station moves from a narrowband time division communication system to a Global System for Mobile Communications (GSM) cell. In the measurement method for handover, Checking whether the mobile station requests confirmation of a base station identifier code in measuring the inter-RAT requested from a radio access network (UTRAN) for next generation mobile communication management; Determining, by the mobile terminal, that time for identifying a base station identifier code of the GSM cell is insufficient in the measurable period; If the mobile station fails to identify the base station identifier code, providing a message including absolute radio frequency channel number (ARFCN) information to the UTRAN; And receiving information regarding the changed time slot from the UTRAN by the mobile station.

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