KR100551119B1 - Selected bts roaming method and system in mobile communication system - Google Patents

Abstract

The present invention relates to a roaming method of a base station unit in a mobile communication system capable of roaming by a base station unit.

In a mobile communication system of the present invention, a roaming method of a base station unit includes transmitting a first roaming base station identification number from a base station performing a roaming service, receiving a base station identification number from a mobile communication terminal, and performing a second roaming operation on a roaming area. And determining that it is.

According to the present invention, a service provider can provide a better quality service by performing a roaming service for each base station in a narrow shadow area.

Description

Roaming method and system of base station unit in mobile communication system {SELECTED BTS ROAMING METHOD AND SYSTEM IN MOBILE COMMUNICATION SYSTEM}             

1 is a network configuration diagram schematically showing a conventional mobile communication system.

2 is a flowchart illustrating a conventional terminal initialization process.

3 is a network diagram schematically showing a mobile communication system of the present invention.

4 is a flowchart illustrating a roaming service scheme of the present invention.

5 is a diagram illustrating a roaming list stored in a terminal according to an embodiment of the present invention.

6A illustrates a control unit of a base station according to an embodiment of the present invention.

6B is a diagram illustrating a controller of a terminal according to an embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

2,32: Mobile switching center (MSC) 4,34: General telephone switching network (PSTN)

6,36,37: base station (BTS, BTS (R)) 7, 35: base station controller (BSC)

8,38,48: Terminal 10,40: Visitor Location Register (VLR)

12,42 Home Location Register (HLR) 14,44 Terminal Authentication Device (EIR)

16,46: message center (16) 50,56: control unit

52,58: control module 54,60: operation module

The present invention relates to a method and system for roaming by a base station in a mobile communication system, and more particularly, to a method and system for roaming by a base station in a mobile communication system capable of roaming by a base station.

The mobile communication system provides a voice, integrated service digital network (ISDN), facsimile and data services using a wirelessly connected mobile communication terminal. Such a mobile communication system has a reduction in subscriber network construction cost, time and maintenance cost compared to a wired network, as well as improved call quality due to various subscriber network configurations. In particular, the use population of the mobile communication terminal has exploded due to the convenience of carrying.

1 is a network diagram schematically illustrating a conventional mobile communication system.

Referring to FIG. 1, a conventional mobile communication system includes a mobile switching center (hereinafter referred to as "MSC") 2, a base station (hereinafter referred to as "BTS") 6, a base station controller (Base Station Controller: " BSC " hereinafter) 7 and a mobile communication terminal (Mobile Station: hereinafter " MS ") 8.

The BTS 6 establishes a communication call with the MS 8 using a predetermined protocol. The BTS 6 transmits a radio frequency signal received from the MS 8 to the MSC 2, and transmits a signal received from the MSC 2 to the MS 8.

The BSC 7 relays the communication between the BTS 6 and the MSC 2.

The MSC 2 determines whether it is an authenticated MS 8 and provides a call service in the case of an authenticated MS 8. The MSC 2 is also connected to a public switched telephone network (hereinafter referred to as "PSTN") 4 to relay calls between the MS 8 and the PSTN 4.

The MSC 2 includes a terminal identity device (hereinafter referred to as "EIR") 14, a visitor location register (hereinafter referred to as "VLR") 10, a home location register (Home Location Register). 12 and a message center (hereinafter referred to as "MC") 16 are connected.

In the EIR 14, subscriber authentication information is stored. This EIR 14 confirms via the MSC 2 whether the MS 8 is an authenticated terminal. The VLR 10 manages the location of the visit subscription site and the registration information of the subscriber. The HLR 12 configures and manages subscriber's basic information (including location information) and additional service information in a database. MC 16 provides a message service to MS 8.

Currently, there are various operators operating such mobile communication systems. Therefore, a roaming service is provided to prevent overlapping investment and waste of resources between operators. The roaming service refers to a service that allows an MS 8 subscribing to one mobile service provider to use an existing service using a mobile communication system of another carrier. By providing such roaming service, it is possible to prevent overlapping investment between operators and provide better call quality to subscribers.

Roaming services between carriers are conventionally achieved by using a system identification (SID) and a network identification (NID). SIDs can be used to identify operators by carrier identification numbers. The NID makes it possible to distinguish the MSC 2 by the MSC 2 identification number.

2 is a flowchart illustrating a general terminal initialization process.

Referring to FIG. 2, a system determination substate is a state in which the MS 8 selects a system that can communicate using a code division multiple access (CDMA) channel. . That is, the MS 8 selects a system that can communicate using the scan list stored in the MS 8 (S20). For this purpose, the MS 8 includes the frequencies, SIDs, and NIDs that the MS 8 can use. Information is included.

That is, the MS 8 selects a frequency that it can use by using a search list stored in its memory in the system decision state when power is supplied.

The MS 8 tuned to the frequency selected in step S20 transitions to a pilot channel acquisition substate. In the pilot channel acquisition substate, the MS 8 acquires a pilot channel (S22).

The MS 8 having acquired the pilot channel in step S22 transitions to a synch channel acquisition substate. In the sync channel acquisition substate, the MS 8 acquires SYNC CHANNEL MESSAGE.

In step S24, the MS 8 obtaining the SYNC CHANNEL MESSAGE transitions to a timing change substate. In the timing conversion sub-state, the MS 8 synchronizes time with the base station (S26). At this time, the time is displayed on the display window of the MS 8.

In step S26, the MS 8 whose time coincides with the base station transitions to an idle state. In the idle state, the MS 8 receives a system parameter message and checks whether the SID and NID in this message match the SID and NID pair in its search list (S27).

The MS 8 then provides a service if the SID and NID in the message match the SID and NID pair in its search list. However, the MS 8 repeats steps S20 to S25 if the SID and NID in the message do not match the SID and NID pair included in its search list.

That is, since SID and NID information are conventionally used, roaming is performed in units of MSC (2). In other words, conventionally, roaming is performed between MSC (2) units, i.e., a large area. If roaming is performed between such a large area, roaming is impossible for a narrow shaded area that the operator wants to roam.

Accordingly, an object of the present invention is to provide a method and system for roaming by base station in a mobile communication system capable of roaming by base station.

In order to achieve the above object, a roaming method of a base station unit in a mobile communication system of the present invention includes transmitting a first roaming base station identification number from a base station performing a roaming service, and receiving a base station identification number from a mobile communication terminal. 2 roaming operation to determine the roaming area.

In the first roaming operation, an OR operation is performed with the first roaming number generated by the base station in order to set at least one or more bits set to "0" in the base station identification number to "1". It receives the base station identification number and performs an AND operation on the second roaming number generated by the base station identification number, and checks whether "1" is output from at least one bit set to "1" in the first roaming operation.

In the first roaming operation, an AND operation is performed on the first roaming number generated by the base station to set at least one or more bits set to “1” in the base station identification number to “0”, and a second roaming operation is performed. In operation, the base station identification number is input to perform a logical NOR operation with the second roaming number generated by the base station to check whether "1" is output from at least one or more bits set to "0" in the first roaming operation.

In the mobile communication system of the present invention, a base station-based roaming system includes a base station for outputting a base station identification number with a specific bit changed in order to perform a roaming service, and a mobile communication terminal receiving a roaming service by checking a specific bit of the base station identification number. do.

In the mobile communication system of the present invention, a base station-based roaming system base station includes a control module for controlling the operation of the base station, and a calculation module for calculating a base station identification number whose specific bit is changed to perform a roaming service.

The operation module converts at least one bit among the bits set to "1" and "0" of the base station identification number into the opposite bit using any one of an OR and an OR operation.

In a mobile communication system of the present invention, a roaming system mobile communication terminal for each base station includes a control module for controlling the operation of the mobile communication terminal, and a specific bit of a base station identification number transmitted from the base station for roaming service. It has a calculation module.

The operation module transmits at least one bit among bits set to "1" and "0" of the base station identification number to "1" and "0" using any one of a logical product and a logical-norm operation. Check that the bit changes to the opposite bit.

Other objects and features of the present invention in addition to the above objects will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 to 6B.

3 is a network diagram schematically showing a mobile communication system of the present invention.

Referring to FIG. 3, the mobile communication system of the present invention includes an MSC 32, a BSC 35, a BTS 36, a roaming base station (hereinafter referred to as a " BTS (R) ") 37, and an MS. 38 is provided.

The BTS 36 establishes a communication call with the MS 38 using a predetermined protocol. The BTS 36 transmits a radio frequency signal received from the MS 38 to the MSC 32 and transmits a signal received from the MSC 32 to the MS 38. The BTS 36 is installed in the non-roaming area and plays the same role as the BS 6 shown in FIG.

The MSC 32 determines whether it is an authenticated MS 38 and provides a call service in the case of an authenticated MS 38. The MSC 32 is also connected to the PSTN 34 to relay calls between the MS 38 and the PSTN 34.

The MSC 32 is connected to the EIR 44, the VLR 40, the HLR 42, the MC 46, and the like. In the EIR 44, subscriber authentication information is stored. This EIR 44 confirms via the MSC 32 whether the MS 38 is an authenticated terminal. The VLR 40 manages the location of the visit subscription site and the registration information of the subscriber. The HLR 42 configures and manages the subscriber's basic information (including location information) and additional service information in a database. The MC 46 provides a message service to the MS 38.

On the other hand, the BTS (R) 37 is installed in the roaming area to establish a communication call with the MS 48 of another operator to provide a service. That is, the present invention provides a roaming service in units of base stations.

The operation of the BTS (R) 37 is described in detail as follows. Every BTS 36 and BTS (R) has its own unique identification number (hereinafter referred to as "BASE_ID"). The BTS (R) 37 makes at least one bit of its BASE_ID '1' or '0' and transmits it to the MS 48.

A process of making at least one bit of the BASE_ID into "1" will be described in detail. Here, assume that the BASE_ID is "0000111111111111" (0x0fff), and assume that the upper 2nd and 3rd bits of the BASE_ID of the BTS 36 and the BTS (R) 37 used in all mobile communication systems are "0".

First, the BTS (R) 37 selects between the roaming base station confirmation value (0100000000000000: 0x4000) generated by itself to set the upper 2nd bit (and / or the third bit) of its BASE_ID to "1". Execute the OR operation. At this time, the BASE_ID having undergone the OR operation is set to "0100111111111111" (0x4fff). That is, the upper second bit is set to one.

Thereafter, the BTS (R) 37 sends the BASE_ID that has undergone the OR operation into the BASE_ID field of the system parameter message. Thereafter, the MS 48 checks the setting of the upper 2nd bit of the BASE_ID transmitted from the BTS (R) 37 to receive the roaming service.

On the other hand, the control unit 50 of the BTS (R) 37 is divided into a control module 52 and a calculation module 54 as shown in Figure 6a. The control module 52 controls the operation of the BTR (R) 37. In addition, the control module 52 transmits the roaming base station confirmation value to the calculation module 54. The calculation module 54 performs an OR operation between the roaming base station confirmation value and BASE_ID.

An operation of the mobile communication terminal will be described in detail with reference to FIG. 4.

Referring to FIG. 4, first, the MS 48 selects a frequency that it can use by using a search list stored in its memory in a system determination substate (S50). The MS 48 acquiring the system transitions to a pilot channel acquisition substate. In the pilot channel acquisition substate, the MS 48 acquires a pilot channel (S52).

In step S52, the MS 48, which acquires a pilot channel, transitions to a synch channel acquisition substate. In the sync channel acquisition substate, the MS 48 obtains information of the selected system and timing through pilot channel acquisition (S54).

In step S54, the MS 48, which has acquired the synchronization channel, transitions to a timing change substate. In the timing conversion negative state, the MS 48 synchronizes time with the system selected by the user (S56).

In step S58, the MS 48 synchronized with the system transitions to an idle state. In the idle state, the MS 48 receives a system parameter message, an access channel message, a registration request message, and the like (S58). Here, the BASE_ID field of the system parameter message is received. Contains BASE_ID.

Thereafter, the MS 48 determines whether the SID obtained by the MS 48 is the home system or the SID of the roaming system using the roaming list as shown in FIG. 5 (S60, S64). If the SID, the service is normally performed through the home system (S62).

If the SID acquired in step S60 is not the home system SID, the S48 compares with the roaming SID in the roaming list in step S64, and if it matches, the MS 48 checks whether the BASE_ID obtained in step S58 is the BASE_ID of the roaming base station. (S66) On the other hand, if the SID obtained in step S64 is not a roaming SID in the roaming list, the MS 48 repeats step S50.

The process of S66 will be described in detail. First, the MS 48 performs an AND operation between the roaming base station confirmation value " 0100000000000000 " . For example, if BASE_ID has a value of "0100111111111111" (0x4fff), "0100000000000000" (0x4000) is output by a logical product operation between BASE_ID and the roaming confirmation number. At this time, since the upper 2nd bit is set to "1", the MS 48 receives the roaming service from the BTS (R) 37. (S68)

On the other hand, if BASE_ID has a value of "0000111111111111" (0x0fff), a value of "0000000000000000" (0x0000) is output by an AND operation between BASE_ID and the roaming base station confirmation value. At this time, since the upper 2nd bit is set to "0", the MS 48 passes the control right to the step S50.

Meanwhile, the controller 56 of the MS 48 is divided into a control module 58 and a calculation module 60 as shown in FIG. 6B. The control module 58 controls the operation of the MS 48. In addition, the control module 58 transmits the roaming base station confirmation value to the calculation module 60. The operation module 60 performs an AND operation between the roaming base station confirmation value and BASE_ID.

Meanwhile, the process of making at least one bit of BASE_ID into “0” in the present invention will be described in detail. Here, assume that BASE_ID is "0000111111111111" (0x0fff), and assume that the BASE_ID lower second and third bits of the BS 38 and the BTS (R) 37 used in all mobile communication systems are "1".

First, the BTS (R) 37 selects between the roaming base station acknowledgment value (1111111111111101: 0xFFFD) generated by itself to set the lower 2nd bit (and / or the third bit) of its BASE_ID to "0". Perform an AND operation. At this time, the BASE_ID having undergone the logical product operation is set to "0000111111111101" (0x4ffD). That is, the lower second bit is set to "0".

Thereafter, the BTS (R) 37 sends the BASE_ID which has undergone the logical AND operation to the BASE_ID field of the system parameter message. At this time, the MS 48 checks the setting of the lower second bit of the BASE_ID transmitted from the BTS (R) 37 to receive the roaming service.

An operation of the mobile communication terminal will be described in detail with reference to FIG. 4.

In FIG. 4, only the step S66 will be described since the remaining steps except for the step S66 are already described.

The process of S66 will be described in detail. First, the MS 48 performs a logical-norre operation between the roaming base station confirmation value " 1111111111111101 " Check. If BASE_ID has a value of "0000111111111101" (0x4ffD), "0000000000000010" (0x0002) is output by a logical-norm operation between BASE_ID and the roaming confirmation number. At this time, since the lower second bit is set to "1", the MS 48 receives the roaming service from the BTS (R) 37. (S68)

On the other hand, if the BASE_ID has a value of "0000111111111111" (0x0fff), a value of "0000000000000000" (0x0000) is output by a logical-norm operation between the BASE_ID and the roaming base station confirmation value. At this time, since the lower second bit is set to "0", the mobile communication terminal passes control to step S50.

As described above, according to the roaming method and system for each base station in the mobile communication system according to the present invention, it is possible to provide a roaming service for each base station. Therefore, the operator can provide a better quality of service by performing a roaming service by the base station unit in its narrow shadow area.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (8)

A roaming method for each base station in a mobile communication system, characterized by performing a roaming service, Transmitting a first roaming base station identification number from the base station performing the roaming service; And receiving the base station identification number from the mobile communication terminal to determine a roaming area by performing a second roaming operation. The method of claim 1, In the first roaming operation, an OR operation is performed with the first roaming number generated by the base station in order to set at least one or more bits set to "0" in the base station identification number to "1". The second roaming operation receives the base station identification number and performs an AND operation on the second roaming number generated by the base station identification number, thereby performing a "1" in at least one bit set to "1" in the first roaming operation. Roaming method for each base station in the mobile communication system, characterized in that the output is checked. The method of claim 1, In the first roaming operation, an AND operation is performed on the first roaming number generated by the base station to set at least one or more bits set to “1” in the base station identification number to “0”. In the second roaming operation, the base station identification number is input to perform a logical NOR operation with the second roaming number generated by the base station identification number, and " 1 " in at least one bit set to "0" in the first roaming operation. Roaming method for each base station in the mobile communication system, characterized in that the output is checked. In a roaming system that performs a roaming service, A base station for outputting a base station identification number with a specific bit changed to perform the roaming service; And a mobile communication terminal receiving roaming services by checking a specific bit of the base station identification number. A base station that performs roaming service, The base station, A control module for controlling the operation of the base station; And a computing module for calculating a base station identification number of which a specific bit is changed to perform the roaming service. The method of claim 5, The operation module is characterized in that for changing at least one bit of the bit set to "1" and "0" of the base station identification number to the opposite bit by using any one of the OR and OR operation. Roaming system of base station unit in mobile communication system. A mobile communication terminal for performing a roaming service, The mobile communication terminal, A control module for controlling an operation of the mobile communication terminal; And a computing module for checking a specific bit of a base station identification number transmitted from a base station to perform the roaming service. The method of claim 7, wherein The operation module transmits at least one bit among the bits set to "1" and "0" of the base station identification number to "1" and "0" using any one of a logical product and a logical-norm operation. And a base station-based roaming system in the mobile communication system, characterized in that it checks whether the changed bit is changed to the opposite bit.

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