KR100266872B1 - Method for comprehensive management of pilot off set in mobile telecommunication - Google Patents

Abstract

An integrated management method of pilot offset in a code division multiple access system is disclosed. In this method, the base station management system first receives the unique pilot offset to be changed from the operator and the ID of the base station controller / base station to determine whether the received information is appropriate. If the inputted information is appropriate, the list of all adjacent pilots having the input pilot offset value as the adjacent pilot is searched. In the searched neighbor pilot list, the pilot offset to be changed and the ID of the base station controller / base station having the corresponding pilot offset are configured in one table, and the list of each base station controller and the base station is found using this table to update the pilot offset value. .

Description

Integrated Management of Pilot Offset in Code Division Multiple Access System

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for managing base station identification signals in a mobile communication system. In particular, a pilot offset of a base station in a mobile communication system using a code division multiple access (CDMA) technique The present invention relates to a method for collectively changing all neighbor pilot lists necessary for handoff when changed.

1 is a block diagram of a known code division multiple access system. As shown, a base station transceiver subsystem (BTS) 30, 31 which provides a mobile communication service to a mobile station (MS) 40 moving in a certain area (Cell), and a plurality of A base station controller (BSC) 20 for controlling the base stations 30 and 31 of the base station, and connecting the plurality of base station controllers 20 to a public switched telephone network (PSTN) 11. And a mobile switching center (MSC) 10. A system operator operates and manages the mobile communication network through a base station manager (BSM) connected to the base station controller 20 using a trunk line.

In the CDMA system configured as described above, each base station 30, 31 has a unique Pilot Offset value. Therefore, the mobile terminal 40 distinguishes each of the base stations 30 and 31 through a pilot offset transmitted through the pilot channel from the base stations 30 and 31. The mobile terminal 40 talking to the base station 30 detects a new pilot offset and recognizes that it has entered the service area of the other base station 31.

Cellular mobile communication systems improve the efficiency of use of scarce frequencies, making them available to more users. The concept introduced to further increase the frequency efficiency is a cell division technique, and one of such cell division techniques is sectorization. The sector-cell divides the cell into three equally spaced 120-degree antennas. Each sector has a unique pilot offset, and the mobile terminal recognizes one sector antenna as one base station.

In a cellular system, when a mobile terminal leaves a service region and enters a new region, the call can be continued by the handoff function. Mobile communication systems using a code division multiple access scheme provide various types of handoffs to ensure call continuity. In particular, a method of simultaneously connecting several call paths through one frequency band is called soft handoff, and soft handoff occurring between sectors is called softer handoff.

US Patent No. 5,722,074, "Soft handoff in a cellular telecommunication system" discloses a soft handoff method of a mobile terminal capable of transmitting and receiving wireless signals with at least two base stations.

2 shows a procedure of soft handoff of a mobile terminal. As shown, as the mobile terminal moves from cell 1 to cell 2, the pilot strength of cell 1 gradually decreases and the pilot strength of cell 2 gradually increases. When the pilot strength of the cell 2 is greater than or equal to the specified threshold T_ADD, the mobile station requests a handoff from the base station controller and enters a soft handoff state in which a channel is simultaneously connected with the cell 1 and the cell 2. If the mobile terminal continues to move to the area of cell 2 and the pilot strength of cell 1 becomes less than or equal to T_DROP, and the state continues for more than a predetermined time T_TDROP, the mobile terminal stops communicating with cell 1 and is only connected to cell 2.

A system supporting soft handoff stores a neighbor pilot set for each base station and base station controller. Each system using the CDMA scheme has a neighbor list as data for managing a set of neighbor pilots.

If a pilot offset value of one base station is changed, all neighbor pilot lists of neighbor base stations should be changed. In addition, since the actual number of offsets that can be distributed to the base station is about 41-52, the pilot offset is appropriately allocated to each base station in a similar manner to frequency channel allocation through cell planning. Therefore, the neighbor pilot list of all base stations and base station controllers using the changed pilot offset value must be found and changed.

That is, when a unique pilot offset of one base station is changed, all pilot offsets of all neighboring pilot lists including the corresponding pilot offset should be changed. This is a huge task because it must be done across all systems. In addition, when the cell plan is modified, the pilot offset of the entire service area must be changed as a whole, and thus a method of performing such a task in a batch is needed.

The present invention was devised to solve the problems of the prior art operating as described above, and when changing the pilot offset, a code for collectively changing all pilot offsets of all neighbor pilot lists having the pilot offset as a neighbor pilot. An object of the present invention is to provide an integrated management method of pilot offset in a split multiple access system.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention and the accompanying drawings.

1 is a block diagram of a known code division multiple access mobile communication system.

2 shows a procedure of soft handoff of a mobile terminal.

3 shows a data structure of a unique pilot offset value of a base station (or sector).

4 shows a data structure of a 'paging channel neighbor pilot list' of a base station (or sector).

5 shows a data structure of a 'handoff neighbor pilot list' of a base station controller.

6 is a flowchart illustrating a method for integrated management of pilot offsets according to the present invention.

7 is a flowchart illustrating a process of receiving a pilot offset value to be changed according to the present invention.

8 is a flowchart illustrating a process of searching for a neighbor pilot list according to the present invention.

9 shows a pilot table to be modified constructed by the present invention.

10 is a message flow diagram illustrating a process of updating a pilot offset according to the present invention.

11 is a flowchart illustrating a process of updating a pilot offset value to be changed according to the present invention.

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

10: mobile switching center (MSC)

11: Public Switched Telephone Network (PSTN)

20: base station controller (BSC)

30,31: base station (BTS)

40: mobile terminal

A preferred embodiment of the integrated management method of the pilot offset in the mobile communication system according to the present invention, which is designed to achieve the above object, is a mobile terminal which receives a mobile communication service and distinguishes a base station through a pilot offset, and a mobile device. A base station that provides a mobile communication service to a terminal, has a unique pilot offset, manages pilot offsets of other adjacent base stations as a neighbor pilot list, connects multiple base stations to an exchange, and lists a neighbor pilot list of all base stations belonging to the neighbor pilot list. A mobile communication system having a base station controller for managing a network and a base station management system for managing a plurality of base station controllers,

Receiving, by the base station management system, a unique pilot offset to be changed from an operator;

Retrieving a list of all neighbor pilots having the received pilot offset as a neighbor pilot; And

And finding a pilot offset to be changed in the searched neighbor pilot list and updating the value.

In an embodiment of the present invention, the unique pilot offset is preferably stored in a data structure that stores a pilot offset value using the ID of the base station controller / base station as a key.

The unique pilot offset is preferably shared by a base station, a base station controller, and a base station management system.

In the neighbor pilot list managed by the base station, it is preferable to store pilot offset values by using an ID of a corresponding base station controller / base station and a neighbor ID for distinguishing each pilot offset in the list as a key.

The neighbor pilot list managed by the base station is preferably shared by the base station, the base station controller, and the base station management system.

The neighbor pilot list managed by the base station controller preferably stores pilot offset values by using an ID of the corresponding base station controller / base station and a neighbor ID for distinguishing each pilot offset in the list.

The neighbor pilot list managed by the base station controller is preferably shared by the base station controller and the base station management system.

The receiving process preferably includes receiving a unique pilot offset, an ID of a base station having the corresponding pilot offset, and an ID of a base station controller located above the base station.

The receiving of the input includes: receiving a unique pilot offset, an ID of a base station having a corresponding pilot offset, and an ID of a base station controller located above the corresponding base station;

Treating an operator's input as an error if the base station controller / base station of the received ID is not mounted; And

If the base station controller / base station of the received ID is mounted, it is preferable to check whether the received unique pilot offset is an appropriate value, and if it is not an appropriate value, treating the operator's input as an error.

The determining of whether the inputted unique pilot offset is an appropriate value may be determined as an appropriate value if the inputted pilot offset is a multiple of a pilot-increment interval.

The searching may include reading an adjacent pilot list of the base station controller / base station of the received ID;

Checking whether there is a value in the read adjacent pilot list that matches the inputted unique pilot offset, and if not, returning to reading the other adjacent pilot list;

If there is a match, storing the ID of the base station controller / base station and the neighbor ID in the neighbor pilot list; And

And if there is a base station controller / base station to further check, returning to the step of reading another neighbor pilot list,

In the reading of the neighbor pilot list, preferably, the neighbor pilot list managed by the base station controller is read.

The updating of the value may include: constructing a pilot table to be changed using information input in the receiving process and lists searched in the searching process;

Downloading a pilot table to be changed to all base station controllers in which the base station management system is mounted;

Requesting all the base station controllers on which the base station management system is mounted to update the neighbor pilot list by the pilot table to be changed;

Requesting, by the requested base station controller, the lower base station mounted to update the neighbor pilot list by the pilot table to be changed;

Updating, by the requested lower base station, its neighbor pilot list;

If all of the lower base stations update the neighbor pilot list, the base station controller updating its neighbor pilot list; And

If all base station controllers update the neighbor pilot list, the base station management system preferably includes updating its neighbor pilot list,

Preferably, the pilot table to be changed stores a pilot offset value to be changed by using a base station controller / base station ID and a neighbor ID as a key during the search.

When the requested lower base station updates its neighbor pilot list, it is preferable to update its neighbor pilot list by referring to the pilot table to be changed.

In the step of updating the neighbor pilot list by the base station controller, it is preferable to update the neighbor pilot list with reference to the pilot table to be changed,

The updating of the neighbor pilot list by the base station controller is preferably performed after all subordinate base stations of the base station update the neighbor pilot list and receive an ACK thereto.

The step of updating the neighbor pilot list by the base station management system is preferably performed after all the base station controllers update the neighbor pilot list and receive an ACK therefor.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The present invention is divided into three parts. First, a process of receiving a pilot offset value to be changed from an operator of the system, searching for a neighbor pilot list having the received pilot offset as a neighbor pilot, and searching for and updating a pilot offset to be changed in the found neighbor pilot list.

Each base station stores and stores a pilot offset value of all base stations adjacent to it as a 'Neighbor List of Paging Channel'. The base station controller checks whether the pilot offset signal newly detected by the mobile station is included in the neighbor pilot list, and performs a soft handoff.

In addition, the base station controller stores the neighbor pilot list of its lower base stations and the neighbor pilot list of all base stations belonging to the base station as a 'Neighbor List of Handoff'. Therefore, the 'handoff neighbor pilot list' includes a 'paging channel neighbor pilot list' of all base stations belonging to the base station controller and is stored for each base station.

In this case, when the 'unique pilot offset' of one base station is changed, the work to be performed is as follows.

3 shows a data structure of a unique pilot offset value of a base station (or sector). As shown, it has a data structure of the sector ID and corresponding pilot offset value of the base station. A 'unique pilot' is data managed by a base station (or sector), a base station controller, and a base station management system, and is a value of a pilot offset transmitted through a pilot channel of a base station (or sector).

In order to change the unique pilot offset, first the pilot offset of the base station list is changed, and then the pilot offset of the upper base station controller list is changed. The pilot offset of the base station controller / base station list managed by the base station management system is changed. Finally, the pilot offset of the other base station controller list is changed.

In addition, when the pilot offset of the 'paging channel neighbor pilot list' is changed, operations to be performed are as follows.

4 shows a data structure of a 'paging channel neighbor pilot list' of a base station (or sector). As shown in the figure, a sector ID of the base station, a neighbor ID Nebr_id for distinguishing each pilot offset in the neighbor pilot list, and a corresponding pilot offset value data structure are included. The neighbor ID is the number of maximum neighbor pilot offsets for the paging channel from 0. M _p It has a value up to (MAX_NEBR_FOR_PAGING_CHANNEL). The 'paging channel neighbor pilot list' is data managed by the base station (or sector), the base station controller and the base station management system, and is a list of neighbor pilot offsets transmitted through the paging channel from the base station (or sector).

To change the 'paging channel neighbor pilot list', the pilot offset of the corresponding base station list is first changed, and then the pilot offset of the upper base station controller processor list is changed. The pilot offset of the base station controller / base station list managed by the base station management system is changed. Finally, the pilot offset of the other base station controller list is changed.

5 shows a data structure of a 'handoff neighbor pilot list' of a base station controller. As shown in the drawing, it has a data structure of a sector ID, a neighbor ID Nebr_id, and a corresponding pilot offset value of the base station. The neighbor ID is the maximum number of neighbor pilot offsets for handoff from 0. M _h It has a value up to (MAX_NEBR_FOR_HAND_OFF). The 'handoff neighbor pilot list' has a structure including a plurality of 'paging channel neighbor pilot lists' M _h Is M _p Greater than The 'handoff neighbor pilot list' is data managed by both the base station controller and the base station management system and is a list of neighbor pilot offsets considered for handoff.

When changing the pilot offset of the 'handoff neighbor pilot list', the work to be performed is as follows. First, the pilot offset of the base station controller processor list is changed, and then all pilot offsets of the base station controller / base station list managed by the base station management system are changed. The pilot offset of the other base station controller list is changed.

According to the present invention, when a pilot offset of a sector is changed, one pilot table to be changed is searched for all neighbor pilot lists including the changed pilot offset as a neighbor pilot, and the ID of the system is a key and the pilot offset value to be changed as data. It is configured to download the configured table to each system and change the pilot offset value collectively.

6 is a flowchart illustrating a method for integrated management of pilot offsets according to the present invention. As shown, a process of receiving a unique pilot offset value to be changed from an operator 100, a process of retrieving a list of all neighbor pilots having the received pilot offset value as a neighbor pilot, and a change in the searched neighbor pilot list In operation 300, a pilot offset to be found is updated and its value is updated.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention.

First, a unique pilot offset value to be changed is received from an operator (100). At this time, a corresponding base station controller / base station / sector / pilot offset value is input to check whether an operator input is an appropriate value.

7 is a flowchart illustrating a process 100 for receiving a pilot offset value to be changed according to the present invention. As shown, step 110 of checking whether the base station controller / base station / sector inputted by the operator is mounted; if not mounted, treating it as an error 120; and if equipped, the unique pilot offset value entered. Check if this is a proper value and if it is correct, the step of terminating the input process (120).

The pilot offset is distributed to each base station. At this time, the distribution interval (Pilot-Increment) is determined by the distance between the base stations and the path loss. Therefore, by checking whether the pilot offset is a multiple of the pilot dispensing interval, it is confirmed that it is an appropriate value.

If the operator's input is correct, all neighbor pilot lists that have received pilot offset values as neighbor pilots are searched (200). The neighbor pilot list is searched for all base station controllers (BSCs) and base stations (BTSs) managed by the operator. Search.

8 is a flowchart illustrating a process 200 of searching for a neighbor pilot list according to the present invention. First, the 'handoff neighbor pilot list' of the mounted base station controller / base station / sector is read. (210) In the read 'handoff neighbor pilot list', the pilot offset value matching the unique pilot offset value inputted by the operator is read. If there is a matching pilot offset value (220), it checks again by reading the 'handoff neighbor pilot list' of another mounted base station controller / base station / sector (210). The sector ID and the neighbor ID in the 'handoff neighbor pilot list' are stored (230).

When the search for the 'handoff neighbor pilot list' of all base station controllers / base stations / sectors is finished, the search process ends.

After the discovery process is completed, the pilot offset to be changed is updated in the searched neighbor pilot list. (300) To update the actual data, a unique pilot of the sector or the base station (FIG. 3), a paging channel neighbor pilot list (FIG. 4), and a hand are updated. Changes must be made to three data structures, such as the Off Adjacent Pilot List (FIG. 5).

If you change each element individually, M _h X total number of base stations'. Therefore, in order to perform this operation collectively, a pilot table (Change Pilot Offset Through System) to be changed, which uses a base station controller / base station / sector ID and a neighbor ID as a key, is found.

9 shows a pilot table to be modified constructed by the present invention. As shown in the figure, only a portion of the pilots of the sector (or base station), the paging channel neighbor pilot list, and the handoff neighbor pilot list, which have the received pilot offset value as the neighbor pilot, is configured as one table. In this case, the key for the data is a base station controller / base station / sector ID and a neighbor ID, and the data is a pilot offset value to be changed.

The pilot table to be changed is loaded into the system to update the pilot offset. 10 is a message flow diagram illustrating a process of updating a pilot offset according to the present invention. As shown, first, the base station management system (BSM) downloads the pilot table to be changed to the memory areas of the plurality of base station controllers. (S1) When the base station controller BSC sends an ACK to the base station management system and responds, ( S2) The base station management system requests to update the pilot offset by the pilot table to be changed (S3).

Then, the base station controller requests the base station to update the pilot offset by the pilot table to be changed (S4). At this time, the base station controller extracts and sends only a part corresponding to the base station from the loaded pilot table to be changed. The base station updates the pilot offset value of its own pilot list at the request of the base station controller (S5) and sends an ACK to the base station controller and responds. (S6) The base station controller updates the pilot offset to all base stations that need updating. Request and wait for the ACK.

The base station controller receiving the ACK from all base stations updates the pilot offset values of its own pilot lists (S7) and sends an ACK to the base station management system and responds (S8). Request an update of the offset and wait for the ACK.

The base station management system receiving the ACK from all base station controllers updates the pilot offset values of its own pilot lists. (S9) Through the above process, the update of the pilot offsets to the base station management system and all lists below it. Do this.

11 is a flowchart illustrating a process of updating a pilot offset value to be changed according to the present invention. As shown, a pilot table to be changed is configured into a list of retrieved IDs (310) and the pilot table to be changed is downloaded to all mounted base station controllers and waits for an ACK (320). If an ACK is received from all the mounted base station controllers, all mounted base station controllers are required to update the list data of the base station controller / base station and wait for the ACK. (350) All mounted base station controllers If an ACK has not been received from the base station controller, an error is processed (340). If an ACK is received from all mounted base station controllers, the list data of the base station management system is updated using the pilot table to be changed (370), and the result is output. 380)

The present invention can be variously modified and can take various forms and only the specific embodiments thereof are described in the detailed description of the invention. It is to be understood, however, that the present invention is not limited to the specific forms mentioned in the detailed description of the invention, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood to do.

According to the present invention operating as described above, when a unique pilot offset value of one base station (or sector) is changed in a mobile communication system including a plurality of base station controllers and a base station, all 'paging' having the corresponding pilot as an adjacent pilot The pilot offset data of the channel neighbor pilot list and the handoff neighbor pilot list are automatically searched and updated.

Through the above process, all components of the complex mobile communication system are searched individually, and all lists are simply updated without having to check and change the data. This prevents operator errors that can occur while performing large tasks and ensures the accuracy of data updates.

Claims (18)

A mobile terminal provided with a mobile communication service and distinguishing a base station through a pilot offset, and a base station providing a mobile communication service to the mobile terminal, having a unique pilot offset, and managing pilot offsets of other adjacent base stations as a neighbor pilot list. A mobile communication system having a base station controller for connecting a base station to an exchange and managing a neighbor pilot list of all base stations belonging to the neighbor pilot list and a base station management system managing a plurality of base station controllers, Receiving, by the base station management system, a unique pilot offset to be changed from an operator; Retrieving a list of all adjacent pilots having the received pilot offset as a neighbor pilot; And A method of integrated management of pilot offsets in a code division multiple access system, comprising: finding a pilot offset to be changed in the searched neighbor pilot list and updating the value. 2. The integrated pilot offset management according to claim 1, wherein the unique pilot offset is stored in a data structure that stores a pilot offset value using an ID of a corresponding base station controller / base station as a key. Way. The method of claim 1, wherein the unique pilot offset is shared by a base station, a base station controller, and a base station management system. The code division of claim 1, wherein the neighbor pilot list managed by the base station stores pilot offset values using an ID of a corresponding base station controller / base station and a neighbor ID for distinguishing each pilot offset in the list as a key. Integrated management method of pilot offset in a multiple access system. The method of claim 1, wherein the neighbor pilot list managed by the base station is shared by a base station, a base station controller, and a base station management system. The code of claim 1, wherein the neighbor pilot list managed by the base station controller stores pilot offset values by using an ID of a corresponding base station controller / base station and a neighbor ID for distinguishing each pilot offset in the list. Integrated management method of pilot offset in split multiple access system. The method of claim 1, wherein the neighbor pilot list managed by the base station controller is shared by the base station controller and the base station management system. The code division multiple access system of claim 1, wherein the receiving of the input includes receiving a unique pilot offset, an ID of a base station having a corresponding pilot offset, and an ID of a base station controller located above the corresponding base station. Integrated management of pilot offsets The method of claim 1, wherein the receiving of the input process comprises: Receiving a unique pilot offset, an ID of a base station having the corresponding pilot offset, and an ID of a base station controller located above the base station; Treating an operator's input as an error if the base station controller / base station of the received ID is not mounted; And If the base station controller / base station of the received ID is mounted, checking whether the received unique pilot offset is an appropriate value and treating the input of the operator as an error if it is not an appropriate value, the pilot offset in the code division multiple access system; Integrated management method. The code division multiple access system of claim 9, wherein the determining whether the inputted unique pilot offset is an appropriate value comprises determining that the inputted pilot offset is an appropriate value when the inputted pilot offset is a multiple of a pilot-increment. How to manage integrated pilot offsets. The method of claim 1, wherein the searching is performed. Reading a neighbor pilot list of the base station controller / base station of the received ID; Checking whether there is a value in the read adjacent pilot list that matches the inputted unique pilot offset, and if not, returning to reading the other adjacent pilot list; If there is a match, storing the ID of the base station controller / base station and the neighbor ID in the neighbor pilot list; And And returning to the step of reading another neighboring pilot list if there is a base station controller / base station to be further verified. 12. The method of claim 11, wherein the reading of the neighbor pilot list comprises reading the neighbor pilot list managed by the base station controller. The method of claim 1, wherein the updating of the value comprises: Constructing a pilot table to be changed using information input in the input process and lists searched in the search process; Downloading a pilot table to be changed to all base station controllers in which the base station management system is mounted; Requesting all the base station controllers on which the base station management system is mounted to update the neighbor pilot list by the pilot table to be changed; Requesting, by the requested base station controller, the lower base station mounted to update the neighbor pilot list by the pilot table to be changed; Updating, by the requested lower base station, its neighbor pilot list; If all of the lower base stations update the neighbor pilot list, the base station controller updating its neighbor pilot list; And When all base station controllers update the neighbor pilot list, the base station management system updating its neighbor pilot list. 14. The pilot offset of claim 13, wherein the pilot table to be changed stores a pilot offset value to be changed by using a base station controller / base station ID and a neighbor ID of a neighboring pilot list found during the search as a key. Integrated management method. 15. The method of claim 13, wherein the updating of the neighboring pilot list by the requested lower base station comprises: updating a neighboring pilot list by referring to the pilot table to be changed; How to manage. The method of claim 13, wherein the updating of the neighbor pilot list by the base station controller updates the neighbor pilot list with reference to the changed pilot table. . 15. The method of claim 13, wherein the updating of the neighbor pilot list by the base station controller is performed after all of the subordinate base stations update the neighbor pilot list and receive an ACK therefor. Integrated management of offsets. 14. The method of claim 13, wherein the updating of the neighbor pilot list by the base station management system is performed after all the base station controllers update the neighbor pilot list and receive an ACK for the pilot offset. Integrated management method.