KR20000039683A - Method for managing hard handoff to calling of personal mobile communication scriber - Google Patents

Abstract

PURPOSE: A method for managing hard handoff to calling of a personal mobile communication scriber is provided to prevent continual Ping Pong phenomenon caused by frequent telephone call disconnection. CONSTITUTION: If a hard handoff is required according to the changes of a predetermined personal mobile communication subscriber, a second handoff processor changes a state of handoff practice flag assigned to the predetermined personal mobile communication subscriber formed in a handoff processor on a serving side to control the process to the request for new handoff generated after the hard handoff. The second handoff processor performs a switching process for setting a telephone call path between the serving part and a target part according to the request for hard handoff. After setting the telephone call path, a state conversion timer of the handoff practice flag is driven. If completing the driving, the second handoff processor restores the state of the handoff practice flag as the original state for setting as a state capable of admitting the process according to the request for the new handoff.

Description

How to Handle Hard Handoff for Personal Mobile Subscriber Call

The present invention relates to a hard handoff processing method for a personal mobile communication subscriber call. In particular, a hard handoff process for a personal mobile communication subscriber call that can prevent a ping pong phenomenon from occurring. It is about a method.

The most important thing in providing personal mobile communication service is to ensure maximum mobility of personal mobile subscriber station. This is because the movement of the terminal frequently occurs due to the characteristics of personal mobile communication. For this reason, the handoff function is provided for the personal mobile communication service.

When the mobile subscriber moves from a call originating cell to an adjacent cell, the handoff function connects a new channel allocated from the base station that manages the cell where the mobile subscriber is located to perform normal mobile call processing. Terminator handoff, soft handoff, and hard handoff.

Softer handoff is a function to change the call right in a sector of a subscriber moving from one sector to another in a cell of a sectorized base station, and soft handoff is used for a subscriber's call moving between cells in a base station network. The user who receives the service by operating the two or more channels during the handoff period by setting up a new channel through the physical link already established between the two base stations before disconnecting the existing channel. The transfer is smooth enough that the time to change the currency is unknown. Hard handoff is a function performed when a new base station cannot assign a frequency channel, such as a frequency already in use, in an unavoidable situation due to movement during a call. At the moment, but restarts, the call tone does not connect smoothly at the moment of call transfer, and the subscriber hears a short interruption tone. The handoff supported by the exchange is the hard handoff described above.

As described above, during the hard handoff process supported by the exchange, since the terminal of the corresponding mobile communication subscriber is located in an area where the serving cell and the target cell overlap, the power level received in the corresponding sector of each cell is similar, so that the continuous hand is performed. It is called the ping-pong phenomenon that a call is switched off and continuous call transfer is performed.

For example, as shown in FIG. 1, in a situation where β sectors of a cell under the jurisdiction of the second base station 102 and the third base station 103 partially overlap each other, the mobile station controls the second base station 102. As the third base station 103 moves from the area to the area under the jurisdiction, a handoff is required in the overlapping β-sector area and a new frequency channel is allocated from the third base station 103 so that the call is transferred. When the reception power level from 102 is momentarily increased and a handoff to the second base station 102 is required again, a ping pong phenomenon occurs in which a new frequency channel is allocated from the second base station 102 again and call transfer is performed. .

The ping pong phenomenon increases the number of occurrences as the mobile subscriber stays in the region where the two cells overlap, and if the ping pong phenomenon occurs continuously, the call to the mobile subscriber is blocked.

In order to solve the above problem, the present invention provides a method for processing a hard handoff for a personal mobile communication subscriber call that suppresses processing for a new handoff request for a predetermined time when a hard handoff request for a personal mobile communication subscriber call is made. The purpose is to provide.

In order to achieve the above object, the method according to the present invention, if a hard handoff is required as a predetermined personal mobile communication subscriber moves, serving to suppress the processing of the new handoff request that occurs after the hard handoff Changing a state of a handoff execution flag assigned to a predetermined personal mobile communication subscriber included in the side handoff processing unit; Performing a switching process for setting a call path between the serving side and the target side according to the hard handoff request after the state changing step; after the call path is set, driving a state change timer of the handoff execution flag; And when the timer has been driven, restoring the state of the handoff execution flag to the original state, and setting the state of the handoff execution flag to a state capable of accepting a process according to the new hard handoff request.

1 is an embodiment of a system suitable for performing the hard handoff processing method of the present invention,

FIG. 2 is a functional block diagram of the first exchanger and the second exchanger shown in FIG. 1,

3 is an operation flowchart of an embodiment of a hard handoff processing method of the present invention.

Explanation of symbols for main parts of the drawings

101, 102, 103: first to third base stations

121: The first exchanger

111, 112: First and second support station controller

122: second exchanger

130: Home position register (HLR)

201: first base station controller matching unit

202, 212: mobile subscriber matching subsystem

203, 213: Visitor Location Register (VLR)

204 and 216: first and second handoff processing units

205 and 214: first and second switch processing sections

206 and 215: first and second memories

207, 217: first and second trunk line matching subsystems

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

1 is an embodiment of a system for performing a hard handoff processing method of the present invention, the first base station 101 under the jurisdiction of the first base station controller 111 in the jurisdiction of the first switch 121. A mobile subscriber connected to the second base station 102 under the jurisdiction of the second base station controller 112 existing in the jurisdiction of the second exchanger 122 and the mobile terminal connected to the mobile station is moved in this call. The case where the subscriber has forward handoff to the third base station 103 in the jurisdiction of the first base station controller 111 occurs.

Therefore, in the system shown in FIG. 1, the jurisdiction of the first base station 101, the first base station controller 111 that manages the first base station 101, and the first base station controller 111 to which the mobile subscribers are connected are connected. The third base station 103 which exists in the area and controls the area where the mobile subscriber has moved, the home location register 130 used for mobile call processing, the first base station controller 111 and the home location during mobile call processing. A first exchanger 121 configured to refer to the registrar 130, a second base station 102 to which a mobile subscriber is connected upon initial call setup, a second base station controller 112 for judging the second base station 102, It consists of a second exchanger 122 that governs a second base station controller 112. The first and second exchanges 121 and 122 may be exchanges configured to accommodate both fixed and mobile subscribers, or exchanges configured to provide only personal mobile communication services, respectively.

FIG. 2 is a functional block diagram of the first exchanger 121 and the second exchanger 122 shown in FIG. 1 and illustrates a case in which only a personal mobile subscriber can be accommodated. Accordingly, the first exchange 121 may include a first base station controller matching unit 201 for matching with the first base station controller 111 shown in FIG. 1, and a mobile subscriber matching subsystem for matching for the mobile subscriber ( Subsystem 202, Visitor Location Register 203 which the mobile subscriber matching subsystem 202 refers to when processing a given mobile call, and a first relay line matching subsystem 207 for matching processing with a large country. ), A first handoff processing unit 204 for performing overall handoff processing for the first exchanger 121 in cooperation with the first base station controller matching unit 201 and the first relay line matching subsystem 207, and a space switch. And a time switch, which is controlled by the first handoff processing unit 204 and provided in the mobile subscriber matching subsystem 203 and the first relay line matching subsystem 208. 1 exchanger A first switch processing unit 205 for switching processing in 121 and a memory 206 for storing data required for storage when the first switch processing unit 205 performs an operation.

The second exchanger 140 includes a second base station controller matching unit 211, a mobile subscriber matching subsystem 212, a VLR 213, and a second matching process with the second base station controller 112 shown in FIG. The switch processing unit 214, the second memory 215, the second handoff processing unit 216 that performs the overall handoff processing in the second exchanger 122, and the second relay line matching subsystem 217.

Based on the system configured as described above, the mobile subscriber's party is connected to the first exchanger 121, and the mobile subscriber's mobile subscriber is connected to the second exchanger 122 in the state where the initial call is established and the call is in progress. When a forward handoff occurs to an area under the jurisdiction of the third base station 103 of the exchange 121, the forward handoff process is performed as shown in the flowchart shown in FIG.

That is, if a mobile subscriber who sets up an initial call under the jurisdiction of the second base station 102 has a handoff to the jurisdiction of the third base station 103, the second base station controller 112 and the second base station controller are operated in the same manner as before. The handoff for the mobile subscriber is required to the second handoff processing unit 216 through the matching unit 211.

The second handoff processing unit 216 is operated to the serving side as a handoff is required for the mobile subscriber. Accordingly, when the handoff request message is received from the second base station controller matching unit 211, the second handoff processing unit 216 proceeds to step 301 to turn off the handoff execution flag assigned to the corresponding subscriber. Set to. Accordingly, the second handoff processing unit 216 ignores the new handoff request for the mobile subscriber.

After setting the execution flag to the off state, the second handoff processing unit 216 proceeds to step 302 to perform the switching connection process according to the handoff request. The switching connection is made in the same way as before. That is, since the current handoff has occurred in the exchange period, the second handoff processing unit 216 controls the second relay line matching subsystem 217 to allocate a new timeslot on the serving side, and the first relay line matching subsystem. A handoff request message is sent to 207.

Accordingly, the first relay line matching subsystem 207 corresponding to the target side allocates one new timeslot and transmits a handoff request message to the first handoff processing unit 204. The first handoff processing unit 204 is interworked between the first switch processing unit 205, the mobile subscriber matching subsystem 202, and the first relay line matching subsystem 207, on the target side exchange 121 according to the handoff request. Form a new currency.

When the formation of the new currency on the target side exchange 121 is completed, the second handoff processing unit 216 is notified to the second handoff processing unit 216 through the second relay line matching subsystem 217 on the serving side exchange 122 according to the handoff. Allow new currency paths to be formed. That is, the time slot and voice channel previously connected to the mobile subscriber are disconnected, and the handoff channel and voice channel allocated by using the new channel on the link channel are connected to the call channel set in the serving exchange 122. The call path formed on the target side exchange 121 is connected to complete the call path setting process according to the handoff request.

When the call setup is completed as described above, the second handoff processing unit 216 proceeds to step 303 to drive a timer (not shown) for controlling the handoff flag state transition for the mobile subscriber. The time set for the timer is a movement distance for the area where the handoff process should be performed to another cell from the maximum movement distance of the personal mobile communication subscriber that may be considered to exist in the jurisdiction of the third base station 103 corresponding to the target side. This is the time considering the distance except (or minus).

When the operation of the timer operated during the considered time is completed, the second handoff processing unit 216 proceeds to step 305 through step 304 to restore the handoff execution flag of the subscriber to the on state. Accordingly, the second handoff processing unit 216 performs the processing when a new handoff request occurs in a situation where the corresponding call to the mobile subscriber is maintained.

This handoff process is applicable in addition to the conditions shown in FIG. 1 and FIG. That is, one of two subscribers whose initial call is set up in different base station jurisdictions within the same base station controller moves to a cell area of a base station existing in another jurisdiction of a base station controller within the jurisdiction of the same exchange or the same base station controller as described above. If a subscriber moves from an initial call set up in a different base station jurisdiction within a jurisdiction to another exchange, a handoff is made to the area covered by a third exchange with a call set up in another jurisdiction. Even when it occurs, the hard handoff process according to the present invention as shown in Fig. 3 can be applied.

As described above, the present invention converts the state of the handoff execution flag for the subscriber included in the handoff processing unit present on the serving side when a hard handoff for the personal mobile subscriber subscriber call is requested. By disregarding the handoff request that occurs during the time considering the moving distance in the area, it is possible to prevent the occurrence of continuous ping pong due to frequent call switching, thereby preventing the call cutting situation due to the continuous ping pong phenomenon. It has an effect.

Claims (2)

If a hard handoff is requested as a predetermined personal mobile communication subscriber moves, the predetermined individual provided in the serving-side handoff processing unit can suppress processing of a new handoff request generated after the hard handoff. Changing a state of a handoff execution flag assigned to a mobile subscriber; Performing a switching process for setting a call path between a serving side and a target side according to the hard handoff request after performing the state change step; Driving a state transition timer of the handoff execution flag after the call path is established; And when the timer is driven, restoring the state of the handoff execution flag to an original state, and setting the state to accommodate a process according to the new hard handoff request. A method for processing hard handoff for communication subscriber calls. The mobile station of claim 1, wherein the timer is a distance excluding a movement distance of an area where handoff processing is to be performed to another cell from the maximum movement distance of the personal mobile communication subscriber, which may be considered to exist in a base station jurisdiction of the target side. Hard handoff processing method for a personal mobile subscriber call, characterized in that the time is set to operate in consideration.