KR20040056423A - System and method for managing cache by using cache register in mobile database system - Google Patents

Abstract

PURPOSE: A cache management system and a method for the same are provided to allow the data, stored at a DBMS, to be copied at a data cache of a mobile terminal so that the data, stored at the DBMS, is synchronized with the data, stored at the data cache. CONSTITUTION: The system comprises mobile cache managers(31, 41), and a mobile cache register(11). The mobile cache managers(31, 41), installed at a specific mobile support station, manage a mobile cache which integrates data caches of mobile terminals covered by the specific mobile support station, and in a case that there exists the data, requested by a mobile terminal, at the mobile cache, transmit the data to the mobile terminal. The mobile cache register(11), installed at a specific fixed host, exchanges the data cache of the mobile terminal, generated at a mobile cache, with other mobile cache register, and allows the mobile cache managers(31, 41) to receive a data item access request.

Description

Cache management system and method using cache register in mobile database system {SYSTEM AND METHOD FOR MANAGING CACHE BY USING CACHE REGISTER IN MOBILE DATABASE SYSTEM}

The present invention relates to a cache management system and method using a cache register (CR) in a mobile database system (MDS), in particular, a database management system (DBMS) database in a mobile environment The present invention relates to a system and method for allowing data to be copied to a data cache (DC) of a mobile terminal (MT) and maintaining data consistency between a database and a data cache of a terminal.

In a conventional client-server database management system environment, data caching is a form of data shipping in which a client receives a page of a database mainly accessed by a client from a server, stores it in a cache, and processes a client query on the data in the cache. We tried to reduce the load on the server using the -shipping method. Advances in mobile communications and mobile computing have created the concept of a mobile database, in which a mobile terminal provides a database function by replicating a portion of database data in a fixed network (FN). In this type of mobile database system environment, the terminal stores the data to be used by the application in its data cache. In order to invalidate the data in the cache of the terminal when the data in the database is updated, the database management system broadcasts the update information on the network, and with the update information, the terminal updates its cache data. This method has a problem of increasing network traffic as the frequency of updating the database increases. Therefore, in the past, this problem has been improved by synchronous broadcasting and reducing the size of cache invalidation message.

With the advent of the mobile computing era, users' demands for processing business in wireless communication devices have been increasing. Mobile databases are used in mobile computing environments to meet these needs of users. However, the mobile environment has a problem that the bandwidth of the wireless network is small and the resources of the terminal are limited as well as the user moves so that the terminal is frequently disconnected from the network. Therefore, the mobile terminal replicates some of the database data in the fixed network to manage the database. Provide the functionality of the system. Since the database management system of the mobile database system allows data replication of the database to the data cache of the mobile terminal, data consistency between the cache of the terminal and the database must be maintained. In order to maintain the consistency of data, the data updated by the terminal is processed as a transaction and is reflected in the data cache of the terminal through validation of the database management system, and the database management system sends a cache invalidation message to the terminal whenever the database is updated. Broadcast to update the data item in the data cache of the terminal. Therefore, as the number of update requests to the database increases, the traffic of wired and wireless networks increases and the load of the database management system increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned shortcomings. In the mobile environment, the database management system allows the data in the database to be replicated to the data cache of the mobile terminal, and maintains data consistency between the database and the data cache of the terminal. An object of the present invention is to provide a cache management system and method using a cache register in a mobile database system.

The present invention for achieving the above object is a system for managing cache in a mobile database system having a plurality of Mobile Support Station (MSS) and a plurality of fixed host connected to a fixed network. It is configured in a specific mobile support station, and manages a mobile cache (MC) incorporating the data cache of the terminal covered by the specific mobile support station (Mobile Cache (MC)) and if the data requested by the terminal is present in the mobile cache to the terminal Mobile Cache Manager (MCM); And a Mobile Cache Register (MCR) configured to be configured in a specific fixed host to move the data cache of the terminal created in the mobile cache between mobile caches and allow the mobile cache manager to accept data item access requests of the terminals. Characterized in that.

1 is a block diagram illustrating an embodiment of a cache management system using a cache register in a mobile database system according to the present invention;

2 is a flowchart illustrating a step-by-step process of generating a data cache of a mobile terminal in a mobile cache of a mobile cache manager and registering it in the mobile cache register according to the present invention;

FIG. 3 is a diagram illustrating an area movement in which a mobile terminal moves from a mobile cache of a mobile support station before moving when a mobile terminal moves from an area serviced by one mobile support station to an area serviced by another mobile support station according to the present invention. A step-by-step flow chart of the cache handoff process that moves to the supporting office's mobile cache.

<Explanation of symbols for the main parts of the drawings>

10, 20: fixed host 11: mobile cache register

21: database management system

30, 40: mobile support station 31, 41: mobile cache manager

50, 60: cell 51, 61, 62: radio

52: handoff path 70, 80, 90: mobile terminal

71, 81, 91: Application 72, 82, 92: Data Cache Manager

100: Moving Database System

110: fixed net

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

Figure 1 is a block diagram showing an embodiment of a cache management system using a cache register in the mobile database system 100 according to the present invention, the fixed host 1, 2 (10, 20) is a mobile cache register 11, database management Each system 21 is connected to the fixed network 110, and the mobile support stations 1, 2 (30, 40) are provided with the mobile cache managers 1, 2 (31, 41), respectively, and connected to the fixed network 110. The mobile support stations 1, 2 (30, 40) are configured to support cells (CELL) 1, 2 (50, 60), respectively.

In the figure, the mobile cache of the fixed host 1 (10) that registers and manages the cache identifier for the cache mobility management by the movement of the mobile terminal and the database management system (21) in the fixed host 2 (20) for data item management. In order to support the data cache replication and mobility of the mobile terminal 70 in the register 11 and the cell 1 50 region, the mobile support manager 1 31 and the mobile cache manager 1 31 and cell 2 60 region are supported. In order to support data cache replication and mobility of the mobile terminals 1 and 2 (80 and 90), a mobile cache manager 2 (41) is provided in the mobile support station 2 (40) and connected to the fixed network 110, and an application program ( Application Program: The Data Cache Manager (DCM) 1 (72) and the Application 2 (91) that manage the data cache of the data item in the mobile terminal 1 (70) to perform the AP) (71) Of the data item to the mobile terminal 2 (90) for execution. In the mobile database system 100, which is provided with a data cache manager 2 92 for managing data caches and is connected to a fixed network through a mobile support station by wireless 51, 61, and 62, the mobile terminal is provided from the database management system 21. In order to copy the data item to its own cache and the database management system 21 keeps the cache invalidation message containing the latest updated data item in order to maintain the consistency of the updated data item, the mobile terminal 1,2 (80, 90). Broadcast on).

Increasing the data item update request to the database management system 21 not only increases the load on the database management system 21 but also increases the broadcast frequency of cache invalidation messages for maintaining data item consistency. 31 and 41 register Data Cache Identifiers (DCIDs) 1 and 2 of the mobile terminals covered by the mobile support stations 1 and 2 (30 and 40) to the mobile cache register 11 and the mobile terminals in the cell. Mobile Cache Managers 1, 2 (31, 41), which manage mobile caches in which their data caches are integrated, increase the hit ratio for access of data items between the mobile terminal's data cache and the database management system. Only recently updated data items exist in the mobile cache, and the mobile cache managers 1, 2 (31, 41) are each managed by the data cache managers 1, 2 of the mobile terminal from the current data items in their mobile caches. Since it is possible to independently determine whether to allow the update request of the data item requested by the system 21, the database management system 21 can reduce the frequency of update request of the data item, thereby improving the overall performance of the mobile database system 100. Let's do it.

When the mobile terminal applications 1 and 2 access the data items managed by the database management system 21 in the mobile database system 100, the data cache managers 1 and 2 of the mobile terminal check whether the data items are in their cache. do. When the data item is not in its data cache, the data cache managers 1 and 2 request the data items from the mobile cache managers 1 and 2 of the mobile support stations 1 and 2 to which they belong. Similarly, the mobile cache managers 1 and 2 request access to data items to the database management system when there are no data items in their mobile caches. The database management system that is requested to access the data item finds the data item in the database and broadcasts it to the fixed network in response to the request. The mobile data cache managers 1 and 2 receiving the data items broadcast on the fixed network add data items to their mobile caches and transmit the data items by wireless communication to the data cache managers 1 and 2 of the mobile terminals 1 and 2 that have requested the data items. Send. The data cache manager 1,2 of the mobile terminal adds the data item to its data cache and returns the data item to the application 1,2 that requested the data item.

Data Cache Managers 1 and 2 are Data Cache Identifiers (DCIDs) 1 and 2, respectively, and Mobile Cache Managers 1 and 2 are Mobile Cache Identifiers (MCIDs) 1, respectively. , And 2, and use these identifiers to identify the requestor when requesting data item access and update. The mobile cache manager 1,2 generates a cache of data cache identifiers 1 and 2 in the mobile cache when the mobile cache manager 1,2 that has been requested to access the data item does not have a cache of the data cache identifiers 1,2 in the mobile cache. It requests the mobile cache register to register a pair of data cache identifiers and mobile cache identifiers. The mobile cache register which has been requested to register a pair of (data cache identifier and mobile cache identifier) registers a pair of (data cache identifier and mobile cache identifier) in the mobile cache registration table of the mobile cache register in the process of FIG. 2.

When the mobile terminal application program 1,2 updates the data item, the data cache manager 1,2 of the mobile terminal requests the mobile cache manager 1,2 for transaction processing for the data item update. The mobile cache managers 1 and 2, which are requested to process transactions for data item updates, determine whether the data item update transaction can be approved with the current time stamp (TS) of the data items in the mobile cache and if the approval is possible. Only when the update requested TS of the data item is greater than or equal to the TS of the mobile cache data item, the database management system requests the data item update transaction processing. The database management system requesting the data item update transaction processing, like the mobile cache manager, determines whether to update the data item with the current timestamp TS of the data item and updates the corresponding data item in the database. After updating the data item, the database management system broadcasts a cache invalidation message including the updated data item through the fixed network. Receiving the cache invalidation message including the updated data item, the mobile cache managers 1 and 2 update the data items in their mobile caches with the data items in the cache invalidation message, and the mobile support stations 1 of the mobile cache managers 1 and 2 This message is delivered to the data cache managers 1 and 2 of the mobile terminal covered by, 2. Receiving this message, the data cache managers 1 and 2, like mobile cache managers 1 and 2, update the data items in their data caches with the data items included in the cache invalidation message.

As shown in the handoff path 52 of FIG. 1, when a mobile terminal 1 moves from a current local cell 1 to another local cell 2, hand-off of the mobile terminal occurs. When mobile terminal 1 resets connection or mobile terminal application 1 attempts to access a data item in the local cell 2 to which the terminal has moved, the data cache manager 1 of the terminal uses the data cache identifier 1 as a parameter to the mobile cache manager 2. Request a reconnection or request access to a data item. The mobile cache manager 2 checks whether there is a cache of data cache identifier 1 in its mobile cache, and if there is no data cache identifier 1 cache, the mobile cache manager 2 generates a data cache identifier 1 cache in its mobile cache. Then, the mobile cache register requests the registration of the data cache identifier 1 and the mobile cache identifier 2 by the mobile cache registrar to perform the cache handoff in the process of FIG. 3. By performing the cache handoff, data items of the data cache identifier 1 cache in the mobile cache manager 1 mobile cache are moved to the data cache identifier 1 cache of the mobile cache manager 2 mobile cache.

FIG. 2 shows that the data cache manager 1 (31) managing the mobile cache 1 in which the mobile cache identifier 1 is designated as the identifier is accessed from the data cache manager 1 (72) managing the data cache in which the data cache identifier 1 is designated as the identifier. When the mobile cache manager 1 31 does not have a data cache of the data cache identifier 1 in the mobile cache, the mobile cache manager 1 31 creates a data cache of the data cache identifier 1 in the mobile cache. In the process of registering the data cache identifier and the mobile cache identifier pair (data cache identifier 1, mobile cache identifier 1) with the mobile cache register 11, the mobile cache manager 1 (31) registers the data cache manager 1 (72). Beginning by requesting access to the data item from the user 220. The mobile cache manager 1 31, which is requested to access a data item from the data cache manager 1 72, checks whether the mobile cache manager has a data cache identifier 1 cache (221). If there is a cache of data cache identifier 1 in the mobile cache and a data item exists in the cache of data cache identifier 1 (225), then mobile cache manager 1 31 sends the data item to data cache manager 1 72 ( 227). If there is no data item in the data cache identifier 1 cache of the mobile cache, the data item is accessed from the database management system and stored in the data cache identifier 1 cache (226), and the data item is transmitted to the data cache manager 1 (227).

However, if there is no cache of the data cache identifier 1 in the mobile cache, the mobile cache manager 1 31 generates a cache of the data cache identifier 1 in the mobile cache (222). The mobile cache manager 1 31, which has generated the cache of the data cache identifier 1 in the mobile cache, requests the mobile cache register 11 to register its own (data cache identifier 1, mobile cache identifier 1) (223). The mobile cache register 11 receives a registration request of (data cache identifier 1, mobile cache identifier 1) in the reception mode standby state 210 (211). The mobile cache register 11 which has been requested to register (data cache identifier 1, mobile cache identifier 1) checks whether data cache identifier 1 is registered in its mobile cache registration table (212). If the data cache identifier 1 is not registered in the mobile cache registration table, the mobile cache register 11 inserts (data cache identifier 1, mobile cache identifier 1) into the mobile cache registration table (213), and the mobile cache manager 1 ( 31, the mobile cache manager 1 (31) receives the REG_OK for the completion of registration (data cache identifier 1, mobile cache identifier 1) from the mobile cache register 11 (224), and moves (224) Registration of the data cache identifier 1 and the mobile cache identifier 1 of the data cache generated in the cache is completed. After completing the registration of (data cache identifier 1, mobile cache identifier 1), the mobile cache register 11 waits for reception of another cache identifier registration request. The REG_OK is a return value or flag of the mobile cache register and is a return value for a successful processing result of the mobile cache registration request.

3 illustrates a data cache identifier of a mobile cache manager 1 31 in a mobile cache before moving when mobile terminal 1 70 moves from one local cell 1 50 to another local cell 2 60. The mobile cache identifier 2 of the region to which the data cache of 1 is moved is moved to the mobile cache of the mobile cache manager 2 41 that manages the mobile cache designated as the identifier, and the mobile cache register 11 moves the data cache of the mobile cache registration table. In the cache handoff process of updating the identifier 1 and the mobile cache identifier 1 to the data cache identifier 1 and the mobile cache identifier 2, the process of FIG. 2 is performed in the cell 1 50 region to the mobile cache of the mobile cache manager 1 31. Mobile terminal 1 70, which has created a data cache of data cache identifier 1, moves to cell 2 60 region, and data cache manager 1 82 of the terminal accesses the data item to mobile cache manager 2 41. request. The mobile cache manager 2 41, which is requested to access the data item, generates a data cache of the data cache identifier 1 in the mobile cache in the same manner as in the process of FIG. 2, and sends the data cache identifier 11 to the data cache identifier 1 (data cache identifier 1, Request registration of mobile cache identifier 2). The mobile cache register 1 (11), which has been requested to register (data cache identifier 1 and mobile cache identifier 2), has the data cache identifier 1 and mobile cache only when data cache identifier 1 is registered in its mobile cache registration table. 3 starts by checking whether a pair of identifiers 1) is already registered.

If (Data Cache Identifier 1, Mobile Cache Identifier 1) is already registered and the Requestor for Registration is Mobile Cache Manager 1 (310) (310), Mobile Cache Register 11 sends REG_OK to Mobile Cache Manager 1 (31) ( 311) Return to the registration request reception state again. If the requester's (data cache identifier 1, mobile cache identifier 1) is not registered, the data cache identifier 1 is returned to the mobile cache manager 2 41 (312). The mobile cache manager 2 41 requests the registration of (data cache identifier 1, mobile cache identifier 2) (320) and receives the data cache identifier 1 from the mobile cache register 11 in response to the registration request (321). Mobile cache manager 2 41 requests mobile cache manager 31 to send a data item of the data cache identifier 1 cache to SENDREQ (322). The mobile cache register 11 which returns the data cache identifier 1 to the mobile cache manager 2 41 instructs the mobile cache manager 1 31 to transfer the data item of the data cache identifier 1 cache to the mobile cache manager 2 41. Wait for transmission completion (313). While the mobile cache manager 1 (31) is waiting in the reception mode (330), the mobile cache manager 1 (31) receives the MOVE, DELETE instruction of the data cache identifier 1 cache from the mobile cache register 11 or the mobile cache manager 2 Receive a SENDREQ request from 41 (331). From the received message (here, move the cache move destination of MOVE and SENDREQ, cache manager 2, and the target of the cache DELETE as data cache identifier 1). Move the destination of the cache of data cache identifier 1 of MOVE and SENDREQ. If the target of the DELETE is designated as the data cache identifier 1 (332), and then the target of the DELETE is designated as the data cache identifier 1 (333), the mobile cache manager 1 (31) is the data cache identifier 1 in its own mobile cache. Clear the cache (339) and wait in the receive mode again. If the MOVE instruction and SENDREQ are requested (334), the mobile cache manager 1 (31) sends all data items to the mobile cache manager 2 (41); otherwise, the mobile cache manager 1 (31) sends the MOVE, SENDREQ. Wait for all to be instructed. When Mobile Cache Manager 1 (31) sends a data item to Mobile Cache Manager 2 (41), Mobile Cache Manager 2 (41) receives the data item and receives the received data item rather than the timestamp of the data item in its mobile cache. The data item in the mobile cache of the mobile cache manager 2 (41) is updated with the received data item only when the time stamp is large (323). After completing the data item update, the mobile cache manager 2 (41) responds to the mobile cache manager 1 (31) with RECV_OK for reception of the data item (324). The mobile cache manager 1 (31) transmits a data item to the mobile cache manager 2 (41) and receives the RECV_OK from the mobile cache manager 2 (41). The mobile cache manager 1 (31) transmits a MOVE_OK to the mobile cache register (11) (337). . The mobile cache register 11 that receives MOVE_OK in response to the MOVE completion from the mobile cache manager 1 31 (314) selects (data cache identifier 1, mobile cache identifier 1) of the mobile cache registration table (data cache identifier 1, mobile). Cache identifier 2) (315). After completing the update, the mobile cache register 11 instructs the mobile cache manager 1 31 to remove the data cache identifier 1 cache (316) and completes the cache handoff.

The MOVE is a command or flag that instructs the mobile cache register to move the specified data cache in the mobile cache manager A's mobile cache to another mobile cache manager B's mobile cache. DELETE is a command or flag that instructs the mobile cache manager to delete the data cache of the data cache identifier specified in the mobile cache. SENDREQ is a command or flag that requests the mobile cache manager A to send the data cache contents of the data cache identifier specified in B's mobile cache to B. RECV_OK is a return value that responds to the completion of data items after reflecting the data items received after the SENDREQ request to the designated data cache of the mobile cache. MOVE_OK is a value returned in response to a MOVE command.

The mobile database system also supports the mobility of the database. A mobile terminal is an information terminal carried by a user, such as a PDA, and has a means or an interface capable of wireless communication with a mobile support station or a mobile support station. The data cache is a memory or disk space allocated within the mobile terminal that copies and stores data for use by the mobile terminal. The data cache manager is a module or software that manages the data cache of the mobile terminal. The data cache identifier is an identifier for identifying the data cache. The mobile support station provides a means for wireless communication with the mobile terminal and a means for communication between wired and wireless. The mobile cache has a copy of each mobile terminal data cache covered by the mobile support station as a cache in memory or disk space allocated within the mobile support station. The mobile cache manager is a module or software that manages the mobile cache at the mobile support station. The mobile cache identifier is an identifier for identifying the mobile cache. The handoff is when the user moves to another mobile support station, the mobile cache corresponding to the data cache of the mobile terminal moves from the mobile support station before the movement to the mobile support station after the movement. The Mobile Cache Register manages registrations such as inserting and deleting pairs (data cache identifiers and mobile cache identifiers) into tables or databases. A fixed network is a wired network. Data items are data in the database. A cell is an area in which a mobile support station can communicate wirelessly with mobile terminals it covers.

As described above, the present invention includes a mobile cache register in a fixed network for providing a data cache handoff of a terminal generated in a mobile cache manager and a mobile cache of a mobile cache manager to a mobile support station between a terminal and a database management system. In addition, the mobile cache manager stores and manages data items broadcasted by database access and update in the mobile cache, and keeps the mobile cache up to date. Since data items accessed by terminals in the area covered by the mobile support station are in the mobile cache, it is highly likely that the data items requested by the terminal to the database management system are present in the mobile cache. On behalf of the database management system, the data item requested by the terminal can be immediately transferred. Transaction processing of a data item for reflecting the data item updated by the terminal to the database management system is accepted by the mobile cache manager. If the data item is in the mobile cache, the mobile cache manager approves based on the time stamp of the data item. It sends potential processing requests to the database management system for transactions that are likely to update data items larger than the timestamp of the data items in the mobile cache, reducing network traffic and reducing the database management system load due to database updates. This improves the overall performance of the mobile database system.

Claims (4)

A system for managing cache in a mobile database system having a plurality of mobile support stations and a plurality of fixed hosts connected to a fixed network, the system comprising: A mobile cache manager configured in a specific mobile support station to manage a mobile cache incorporating the data cache of the terminal covered by the specific mobile support station and to transmit the data requested by the terminal to the terminal if data exists in the mobile cache; And A cache register is configured in a mobile database system including a mobile cache register configured in a specific fixed host to move a data cache of a terminal created in the mobile cache between mobile caches and allow the mobile cache manager to accept a data item access request of the terminal. Cache Management System. A fixed host 1 having a mobile cache register, a fixed host 2 having a database management system, and a mobile support station 1, 2 having mobile cache managers 1, 2 and supporting cells 1, 2, respectively, are connected to the fixed network. A cache management method in a cache management system using a cache register in a mobile database system having a configuration, A first step in which the mobile cache manager 1 managing the mobile cache 1 in which the mobile cache identifier 1 is designated as the identifier is requested to access a data item from the data cache manager 1 managing the data cache in which the data cache identifier 1 is designated as the identifier; ; A second step of the mobile cache manager 1 generating a data cache of the data cache identifier 1 in the mobile cache when the mobile cache manager 1 does not have a data cache of the data cache identifier 1 in the mobile cache; Registering a pair of data cache identifiers and mobile cache identifiers (data cache identifier 1, mobile cache identifier 1) with the mobile cache register; When the mobile terminal 1 in the cell 1 region moves to the other region cell 2, the data cache identifier 2 of the region where the mobile cache manager 1 of the region before the movement moves the data cache of the data cache identifier 1 in its mobile cache. A fourth step of moving to the mobile cache of the mobile cache manager 2 managing the mobile cache designated by the identifier; And And a fifth step of the mobile cache register performing a cache handoff to update the (data cache identifier 1, mobile cache identifier 1) to (data cache identifier 1, mobile cache identifier 2). Cache management method using. The method of claim 2, Step 31, the mobile cache manager 1 managing the mobile cache 1 in which the data cache identifier 1 is designated as the identifier from the data cache manager 1 managing the data cache in which the data cache identifier 1 is designated as the identifier, receives a data item access request; ; When the mobile cache manager 1 does not have the data cache of the data cache identifier 1 in the mobile cache at the time when the data item access request of step 31 is received, the mobile cache manager 1 performs the data cache of the data cache identifier 1. Generating in the mobile cache a thirty-second step; A thirty-third step of registering a pair of data cache identifiers and mobile cache identifiers (data cache identifier 1, mobile cache identifier 1) with the mobile cache register; A thirty-fourth step in which the mobile cache manager 1 receives a request for access of a data item from the data cache manager 1 and the mobile cache manager 1 checks whether there is a cache of the data cache identifier 1 in its mobile cache; If there is a cache of the data cache identifier 1 in the mobile cache and a data item exists in the cache of the data cache identifier 1, the mobile cache manager 1 sends the data item to the data cache manager 1; If there is no data item in the data cache identifier 1 cache of the mobile cache, accessing the data item from the database management system and storing it in the data cache identifier 1 cache, and transmitting the data item to the data cache manager 1; When there is no cache of the data cache identifier 1 in the mobile cache, the mobile cache manager 1 that generates the cache of the data cache identifier 1 in the mobile cache of the mobile cache manager 1 sends the data cache identifier 1 to the mobile cache register. Requesting for registration of the cache identifier 1) step 37; When the mobile cache register is in a reception mode standby state, the data cache identifier 1 and the mobile cache identifier 1 receive a registration request, and the mobile cache register registers the data cache identifier 1 and the mobile cache identifier in its mobile cache registration table. Checking for whether 1 is registered; A 39th step of inserting the data cache identifier 1 and the mobile cache identifier 1 into the mobile cache registration table when the data cache identifier 1 and the mobile cache identifier 1 are not registered in the mobile cache registration table; Responding REG_OK to the mobile cache manager 1, thereby allowing the mobile cache manager 1 to receive REG_OK for completion of registration (data cache identifier 1, mobile cache identifier 1) from the mobile cache register; And And completing a registration of the data cache identifier 1 and the mobile cache identifier 1 generated in the mobile cache and the mobile cache register waiting for the reception of another cache identifier registration request. Cache management method using register. The method of claim 2, Requesting for the registration of the data cache identifiers 1 and 2 and checking whether the (mobile cache identifier 1) pair is already registered in the mobile cache registration table in the mobile cache registration table; Step 43, when the data cache identifier 1 and the mobile cache identifier 1 are already registered and the registration requester is the mobile cache manager 1, the mobile cache register sends REG_OK to the mobile cache manager 1 and returns to the registration request reception state again. ; When the data cache identifier 1 and the mobile cache identifier 1 are not registered, when the data cache identifier 1 is returned to the mobile cache manager 2, the mobile cache manager 2 may determine the data cache identifier 1 and the mobile cache identifier 2. Step 44 of requesting registration; After receiving the data cache identifier 1 from the mobile cache register in response to a registration request, the mobile cache manager 2 requests the mobile cache manager 1 to send a data item of the data cache identifier 1 cache to SENDREQ. step; The mobile cache register instructing the mobile cache manager 1 to transmit the data item of the data cache identifier 1 cache to the mobile cache manager 2; The mobile cache manager 1 receives the MOVE, DELETE instruction of the data cache identifier 1 cache from the mobile cache register or waits for the completion of the transmission of step 46 from the mobile cache manager 2. A forty-seventh step of receiving a SENDREQ request; From the received message of step 47, if the moving destination of the data cache identifier 1 cache of MOVE and SENDREQ is designated as the moving cache manager 2, the target of DELETE is designated as the data cache identifier 1, and then the DELETE target is designated as the data cache identifier 1 The mobile cache manager 1 removes the data cache identifier 1 from its mobile cache and waits for a reception mode again; Step 49, if the MOVE instruction and SENDREQ are requested, the mobile cache manager 1 sends all data items to the mobile cache manager 2; otherwise, the mobile cache manager 1 waits for both MOVE and SENDREQ to be indicated; When the mobile cache manager 1 transmits a data item to the mobile cache manager 2, the mobile cache manager 2 receives the data item and the time stamp of the received data item is greater than the time stamp of the data item in its mobile cache. Updating the data item in the mobile cache of the mobile cache manager 2 with the received data item; The mobile cache manager 1 receiving the RECV_OK from the mobile cache manager 2 when the mobile cache manager 2 responds to the mobile cache manager 1 with a RECV_OK by the mobile cache manager 2 transmitting a MOVE_OK to the mobile cache register; The mobile cache register receiving MOVE_OK in response to a MOVE completion from the mobile cache manager 1 and updating the (data cache identifier 1, mobile cache identifier 1) to a data cache identifier 1 and a mobile cache identifier 2; And And the fifty-seventh step of completing a cache handoff by instructing the mobile cache manager 1 to remove the data cache identifier 1 cache.