KR100525382B1 - Handoff Method in CDMA Communication System - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CDMA communication system, and more particularly to a handoff method of a CDMA communication system in which a mobile station in which a voice data call is activated and a packet data call is doped is handed off to a region where a region identifier (PZ_ID) is changed. It is about. The handoff method of the CDMA communication system according to the present invention provides a method for handing off a call of the second information transmitted from the second base station after the mobile station makes a call connection handoff of the first information from the first base station to the second base station. Comparing the area identifier (PZ_ID) with the area identifier (PZ_ID) for the call of the mobile station's currently held second information; if the comparison is different, the mobile station calls the second base station with the second information; Sending an initialization message to request a handoff of the second information. Therefore, the present invention uses an In-traffic System Parameter Message, which is used in the prior art, so that no additional hardware device is required.

Description

Handoff Method in CDMA Communication System

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CDMA communication system, and in particular, a hand of a CDMA communication system performed when a mobile station in which a voice data call is active and a packet data call is doped is handed off to an area where a region identifier (PZ_ID) is changed. It's about how to turn off.

In general, the handoff is to continuously search for the pilot signal strength of the source base station and the neighboring base stations that the mobile station is currently serving to the mobile station, and the pilot signal strength of the discovered base stations and the pilot signal strength set at the current source base station. And compare each of them to report the source base station to handoff the neighboring base station or sector when the pilot strength of the neighboring base station exceeds a certain value. Instruct the mobile station to perform the off. Thus, the mobile station can continue the call while securing a new call channel.

In a cellular / personal communication service (PCS) telephone system, if a mobile station hands off between the same frequency, same frame offset, base station or sector belonging to the same exchange, Use a soft handoff to support the new channel. However, when a mobile station moves to a base station belonging to another switching station, when changing a communication channel to another frequency channel, or when changing to a communication channel having a different frame offset, hard handoff is used.

On the other hand, the third-generation mobile communication (3GPP2), which will be commercialized in the future, is different from the handoff method as a concurrent service is provided to support not only voice data but also data services. Support handoff method of.

In particular, when the voice data service is ongoing and the mobile station in which the data service is dormant has hard handed off to the area where the Packet Zone Identifier (PZ_ID) is changed, the mobile station has a paging channel as a traffic channel occupancy state. Does not recognize the PZ_ID change and thus does not initiate a dormant handoff. In this situation, when the packet data service is resumed after the hard handoff is completed, the packet control function (PCF) and the packet data serving node (PDSN) are not the target base station where the actual mobile station is located. There is a problem in that it is impossible to provide a packet data service to a corresponding mobile station because it will attempt to service a base station.

Accordingly, an object of the present invention has been made in view of the above-mentioned problems of the prior art, and by handing off an information message for a changed PZ_ID to a mobile station with a voice call activated through a traffic channel, handoff to a PZ_ID change area is made. Then, to provide a handoff method of a CDMA communication system to enable packet data service.

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The present invention relates to a method in which a mobile station performs a handoff of an active voice call connection from a first base station to a second base station, and a packet zone identifier corresponding to the second base station. Receiving a message regarding transmission object information including a; comparing a packet identifier and a region identifier corresponding to the first base station and a comparison result; And performing a handoff to the mobile station for a packet data call connection in a dormant state concurrent with the activated voice call. In addition, the present invention provides that a particular mobile station having an active voice call connection and a packet data call connection in a dormant state being in concurrent service with the voice call is configured at the first base station. When performing a handoff to a second base station, a method for controlling handoff to the second base station, the handoff completion message (Handoff) for the active voice call (connection) from the mobile station (Handoff) Receiving a completion message; transmitting, to the mobile station, a BS Ack Order message corresponding to the handoff completion message; and to the mobile station, a local identifier corresponding to the second base station. And transmitting an In-Traffic System Parameter message including a Zone Identifier. A method in which a mobile station in a voice call active state and a packet data call dormant state performs a handoff from a first base station to a second base station, wherein the second base station is active. ) Transmitting an Handoff Completion Message for a voice call; and from the second base station, an in-traffic including a Packet Zone Identifier corresponding to the second base station. Receiving an In-Traffic System Parameter message and sending an MS Ack Order message corresponding to the in-traffic system parameter message to the second base station. In the present invention, the mobile station in the voice call active state and the packet data dormant state is handed off from the first base station to the second base station. If performed, the method for controlling the handoff at the second base station, the method comprising: receiving a handoff completion message for an active voice call from the mobile station; Transmitting, to the mobile station, an in-traffic system parameter message including a packet zone identifier corresponding to the second base station; and from the mobile station, the in-traffic system parameter. And receiving an MS Ack Order message corresponding to the message. Hereinafter, a configuration and an operation according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a diagram illustrating a packet diagram hard handoff flow according to the present invention.

1, a mobile communication system according to the present invention includes a mobile station 101 supporting a concurrent service, a source base station 102 performing call control before handoff is performed, and a handoff. The target base station 104 performs call control after being performed, and the mobile switching center 103 performs overall call control and switch control.

Such a mobile communication system additionally includes a packet control function (PCF) (not shown) and a packet data serving node (PDSN) (PDSN) to support a packet data service among concurrent services. It is operated in conjunction with (not shown).

At this time, the PCF interfaces the PDSN with the mobile switching center 103 and has a unique Zone Identifier (PZ_ID). The PDSN transfers packet data received from the Internet network to the mobile station 101 through the PCF in association with the Internet network.

Since the present invention relates to a procedure when a voice call is activated and a packet data service call performs a hard handoff by a dormant state, a procedure other than the core technical matters of the present invention such as call establishment and release is not described. A description will be given only for the procedure of starting packet packet handoff. Here, the doping state of the packet data service is a point-to-point protocol between the mobile station 101 and the PDSN (not shown) in a state in which no traffic channel is allocated between the mobile station 101 and the source base station 102. Assume that PPP) is set.

Therefore, a detailed description of the packet dormant handoff according to the present invention will be described with reference to FIG. 1 as follows.

First, the source base station (based on a report from the mobile station 101 determining that the pilot signal strength of the target base station 104 satisfies the handoff occurrence condition (T_ADD> threshold) (Pilot Strength Measurement Message: transmits a PSMM message) 102 determines a handoff to the target base station 102, and transmits a Handoff message to the mobile switching center 103 (S10). At this time, the number of the target base station 102 has one or more limited range depending on the support of the system.

The mobile switching center 103 having received the handoff request message transmits a handoff request message to the target base station 104 including a handoff type of hard handoff to the target base station 104. The radio resource allocation is requested (S11).

Upon receiving the handoff request message from the mobile switching center 103, the target base station 104 allocates radio resources necessary for hard handoff, and transmits a null forward traffic channel frame to the mobile station 101. Frame) is transmitted (S12). Then, a handoff request acknowledgment (Handoff Request Ack) message reporting completion of allocation of radio resources for hard handoff is transmitted to the mobile switching center 103 (S13). In this case, the handoff request acknowledgment (Handoff Request Ack) message includes the channel information on the allocated radio resource, thereby transmitting the mobile station 101 to access the newly allocated radio resource channel.

Receiving the Handoff Request Ack message, the mobile switching center 103 prepares to switch a call from the source base station 102 to the target base station 104 and from the target base station 103 to the source base station 102. In step S14, a handoff command message is transmitted. The handoff command message is transmitted with channel information about a radio resource received from the target base station 103.

Upon receiving the handoff command message, the source base station 102 sends a handoff direction message to the mobile station 101 to instruct the mobile station 101 to handoff (S15).

The mobile station 101 transmits an MS Ack Order message to the source base station 102 in response to receiving the Handoff Direction message (S16).

The source base station 102 receiving the MS Ack Order message sends a Handoff Commenced message indicating that the mobile station 101 has recognized that the hard base station 104 has to be hard handed off. Transmit to 103 (S17).

Meanwhile, the mobile station 101 having transmitted the MS Ack Order message to the source base station 102 transmits a reverse traffic channel frame or a preamble to the target base station 104. (S18). In addition, the mobile station 101 transmits a handoff completion message to the target base station 104 in synchronization with the reverse traffic channel frame (S19).

Upon receiving the handoff completion message, the target base station 104 transmits a BS Ack Order message to the mobile station 101 (S20). The target base station 104 then transmits an In-traffic System Parameter Message including the PZ_ID of the target base station 104 to support packet dosing handoff of the mobile station in simultaneous service. (S21). Here, the in-traffic system parameter message is a message including transmission target information from the target base station 104 to the mobile station 101.

The mobile station 101 transmits an MS Ack Order message to the target base station 104 in response to the reception of the in-traffic system parameter message (S22).

Upon receiving the MS Ack Order message S22, the target base station 104 transmits a hand complete message to the mobile switching center 103 indicating the successful completion of the hard handoff of the mobile station 101. do.

The mobile switching center 103 transmits a clear command message to the source base station 102 to release the call resource of the source base station 102.

Source base station 102 sends a message reporting completion of call resource release to mobile switching center 103.

The mobile station 101 determines whether the region identifier PZ_ID received through the in-traffic system parameter message is the same as its region identifier PZ_ID after the resource release of the source base station 102 is performed. In other cases, it is determined to perform packet dosing handoff, and a packet data call initialize message is transmitted to the target base station 104 to request packet dosing handoff.

Finally, the target base station 104, which has received the packet dosing handoff request, completes the packet dosing handoff through a predetermined procedure with a PCF (not shown) associated with it to perform the packet dosing handoff.

As described above, the present invention enables a packet dormant handoff when a hard handoff occurs for a concurrent service call in which a voice service call is activated and a packet data service call is doped. Therefore, since the present invention uses an In-traffic System Parameter Message, which is used in the prior art, to transmit information on the PZ_ID that is changed when performing the above packet doping handoff, no additional hardware device is required.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the examples, but should be defined by the claims.

1 illustrates a packet diagram hard handoff flow in accordance with the present invention.

Claims (16)

The mobile station performing a handoff for an active voice call connection from the first base station to the second base station; Receiving a message regarding transmission object information including a packet zone identifier corresponding to the second base station; Comparing a Zone Identifier corresponding to the first base station with a region identifier corresponding to the second base station; And As a result of the comparison, in a different case, performing a handoff for the dormant packet data call connection with the activated voice call to the mobile station in a concurrent service. A handoff method of a CDMA communication system comprising a. The method of claim 1, The message about the transmission target information is an in-traffic system parameter (In-traffic System Parameter) message, characterized in that the handoff method of the CDMA communication system. The method of claim 2, In response to receiving the in-traffic system parameter message, transmitting a MS Ack Order message to the second base station. . The method of claim 1, The handoff of the dormant packet data call connection may be performed by using a packet data call initial message and a packet data call initial message. Way. The method of claim 1, Wherein the area identifier is for identifying a region corresponding to a specific packet control function (PCF), respectively. The method of claim 1, The doping state of the packet data service is a point-to-point protocol between the mobile station and a packet data serving node (PDSN) in a state in which no traffic channel is allocated between the mobile station and the first base station. -Point Protocol (PPP) is set, the handoff method of a CDMA communication system characterized in that the state. The method of claim 1, CDMA communication system characterized in that the handoff for the active voice call connection and the handoff for the packet data call connection in the dormant state are hard handoffs. Handoff method. The method of claim 1, Performing a handoff for the active voice call connection; Receiving a Null Forward Traffic Channel Frame from the second base station; Receiving a handoff direction message from the first base station; Transmitting, to the first base station, an MS Ack Order message corresponding to the handoff indication message; Transmitting, to the second base station, any one of a frame and a preamble for a reverse traffic channel; Transmitting a Handoff Completion Message to the second base station; And Receiving, from the second base station, a BS Ack Order message corresponding to the handoff complete message; A handoff method of a CDMA communication system comprising a. A particular mobile station having an active voice call connection and a packet data call connection in a dormant state in concurrent service with the voice call is handed from the first base station to the second base station. In the case of performing off, the method for controlling the handoff to the second base station, Receiving, from the mobile station, a Handoff Completion Message for the active voice call connection; Sending a BS Ack Order message corresponding to the handoff complete message to the mobile station; And Transmitting, to the mobile station, an In-Traffic System Parameter message including a Packet Zone Identifier corresponding to the second base station. A handoff method of a CDMA communication system comprising a. The method of claim 9, Receiving an MS Ack Order message corresponding to the In-Traffic System Parameter message from the mobile station. The method of claim 9, And performing a handoff on the packet data call connection in the dormant state by receiving a Packet Data Call Initiallze Message from the mobile station. The method of claim 9, Wherein the area identifier is for identifying a region corresponding to a specific packet control function (PCF), respectively. A method in which a mobile station in a voice call active state and a packet data call dormant state performs handoff from a first base station to a second base station, comprising: Transmitting, to the second base station, a handoff completion message for an active voice call; Receiving, from the second base station, an In-Traffic System Parameter message including a Packet Zone Identifier corresponding to the second base station; And Transmitting, to the second base station, an MS Ack Order message corresponding to the in-traffic system parameter message; A handoff method of a CDMA communication system comprising a. The method of claim 13, And a concurrency service of the voice call active state and the packet data call dormant state. When the mobile station in the voice call active state and the packet data call dormant state performs the handoff from the first base station to the second base station, the second base station controls the handoff. In the method, Receiving, from the mobile station, a Handoff Completion Message for an active voice call; Sending, to the mobile station, an In-Traffic System Parameter message including a Packet Zone Identifier corresponding to the second base station; And Receiving, from the mobile station, an MS Ack Order message corresponding to the in-traffic system parameter message; A handoff method of a CDMA communication system comprising a. The method of claim 15, And a concurrency service of the voice call active state and the packet data call dormant state.