KR100380995B1 - The control method of traffic service by soft hand-off in CDMA cellular system - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a traffic service control method by soft handoff in a mobile communication system and a computer readable recording medium having recorded thereon a program for realizing the method.

2. The technical problem to be solved by the invention

In the present invention, a base station using a plurality of CDMA channels allocates a part of a communication channel of a CDMA common frequency band to data traffic, and when performing hand-off, performs soft handoff in the case of data traffic to process traffic. The present invention provides a data traffic service control method for efficiently controlling an error-sensitive data traffic service, and a computer-readable recording medium recording a program for realizing the method.

3. Summary of Solution to Invention

The present invention provides a method of controlling a traffic service in a code division multiple access (CDMA) mobile communication system, wherein, upon receiving a call processing request, a CDMA base station retrieves a channel usage of a current base station to allocate a radio resource, and then performs a primary CDMA channel. A first step of analyzing the use state of the; As a result of the analysis of the first step, the number of ongoing traffic in the primary CDMA channel is a predetermined threshold (preferably, the number of call channel traffic reserved for priority to the data service at the maximum number of traffic that can be provided in the primary CDMA channel). A second step of retrieving the type of traffic currently requested for processing, and assigning the currently requested traffic to the call channel of the primary CDMA channel if less than a threshold value; A third step of unconditionally allocating to a frequency channel other than the primary CDMA channel for voice traffic and determining whether the primary CDMA channel is available for data traffic according to the traffic type search result of the second step; And as a result of the determination in the third step, if available, give priority to data traffic and assign it to the call channel of the primary CDMA channel, thereby reducing hand-to-frequency hard handoff by causing handoff between primary CDMA channels during handoff. And performing a soft handoff, and if not available, assigning to a frequency channel other than the primary CDMA channel.

4. Important uses of the invention

The present invention is used for cell-to-cell handoff and the like in a CDMA mobile communication service.

Description

The control method of traffic service by soft hand-off in CDMA cellular system

The present invention provides a method for processing data traffic by performing a soft hand-off that guarantees quality of service in a code division multiple access (CDMA) mobile communication system, and a program for realizing the method. The present invention relates to a computer-readable recording medium having recorded thereon.

CDMA base station can use multiple CDMA channels of 1.25Mhz frequency band and must include CDMA common channel for initial acquisition of UE, so base station uses as many CDMA channels as necessary according to traffic environment. do. In such a CDMA cell environment, when a handoff occurs between base stations, inter-frequency hard handoff should be performed when the CDMA channel currently being used by the call is not serviced by a neighboring base station. In contrast to hard hand-off, hard hand-off is temporary due to the break-before-make, unlike soft hand-off where make-before-break occurs. A call break occurs. Accordingly, some packet loss is not a big problem in the delivery of packetized voice information, but may have a serious effect in the case of data service. In this case, retransmission is necessary to correct an error in a data service such as a file transfer in which an error is not tolerated. This causes a decrease in throughput, and in the synchronous data transmission, error recovery by retransmission may not be possible. have.

The present invention has been proposed to solve the above-mentioned problems. In the base station using a plurality of CDMA channels, a part of the communication channel of the CDMA common frequency band is allocated to the data traffic to hand-off data. Provides a data traffic service control method for efficiently controlling an error-sensitive data traffic service by performing soft handoff in case of traffic, and a computer-readable recording medium recording a program for realizing the method. do.

1 is a configuration diagram of an embodiment of a CDMA mobile communication system to which the present invention is applied.

2 is a diagram illustrating frequency channel allocation in a CDMA mobile communication system to which the present invention is applied.

3 is a block diagram of a cell using multiple CDMA frequency channels.

4 is an embodiment traffic control flow diagram for increasing soft hand-off for a data service in accordance with the present invention.

* Explanation of symbols for the main parts of the drawings

101 mobile station (MS) 102 base station control processor (BCP)

103: base station control processor interchange network (BIN)

104: Code Division Multiple Access Interchange Network (CIN)

105: transcoding selector bank (TSB) 106: base station (BTS)

107: MSC 108: Call Control Processor (CCP)

109: base station manager (BSM) 110: authentication center (AC)

111: Home Location Register (HLR)

In order to achieve the above object, the present invention provides a traffic service control method in a code division multiple access (CDMA) mobile communication system, wherein, when a call processing request is received, the CDMA base station uses the channel usage of the current base station for radio resource allocation. A first step of searching for and analyzing a usage state of the primary CDMA channel; As a result of the analysis of the first step, the number of ongoing traffic in the primary CDMA channel is a predetermined threshold (preferably, the number of call channel traffic reserved for priority to the data service at the maximum number of traffic that can be provided in the primary CDMA channel). A second step of retrieving the type of traffic currently requested for processing, and assigning the currently requested traffic to the call channel of the primary CDMA channel if less than a threshold value; A third step of unconditionally allocating to a frequency channel other than the primary CDMA channel for voice traffic and determining whether the primary CDMA channel is available for data traffic according to the traffic type search result of the second step; And as a result of the determination in the third step, if available, give priority to data traffic and assign it to the call channel of the primary CDMA channel, thereby reducing hand-to-frequency hard handoff by causing handoff between primary CDMA channels during handoff. And performing a soft handoff, and if not available, assigning to a frequency channel other than the primary CDMA channel.

Meanwhile, the present invention provides a method for analyzing a state of use of a primary CDMA channel by retrieving channel usage of a current base station for radio resource allocation by a CDMA base station upon receiving a call processing request for traffic service control by soft handoff. 1 function; As a result of the analysis of the first function, the number of ongoing traffic in the primary CDMA channel has a predetermined threshold (preferably, the number of call channel traffic reserved for priority to the data service at the maximum number of traffic that can be provided in the primary CDMA channel). A second function for retrieving the type of traffic currently required for processing if greater than or equal to, and for allocating the currently requested traffic to the call channel of the primary CDMA channel if less than a threshold; A third function for unconditionally assigning to a frequency channel other than the primary CDMA channel for voice traffic and determining whether the primary CDMA channel is available for data traffic according to the traffic type search result of the second function; And as a result of the determination of the third function, if available, give priority to data traffic and assign it to a call channel of a primary CDMA channel, thereby reducing hand-to-frequency hard handoff by causing a handoff between primary CDMA channels during handoff. The present invention provides a computer-readable recording medium having recorded thereon a program for realizing a fourth function of performing a soft handoff and performing a soft handoff and assigning to a frequency channel other than the primary CDMA channel if not available. If the load of the service reaches a certain threshold (the maximum number of traffic available on the primary CDMA channel minus the number of call channel traffic reserved for priority to the data service), the data channel's usage priority for the primary CDMA channel is changed. Call so that the data service call is assigned to the primary CDMA channel. And, thus handle the traffic by reducing the inter-frequency hard handoff to make a handoff when a handoff occurs between the Primary CDMA channel generates a soft hand-off. This quality of service can be improved by prioritizing error-sensitive data traffic over voice.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of an embodiment of a CDMA mobile communication system to which the present invention is applied.

The MS represents a Mobile Station (MS) 101, and the BCP is a BTS Control Processor (BCP) 102 that manages the base station. The CDMA Interconnection Network (CIN) 104 and the BCP Interconnection Network (BIN) 103 are responsible for transmitting packet-type control and traffic messages between designated processors. . Transcoding Select Bank (TSB) 105 is coupled to CIN 104 to match traffic voice data with base station (BTS) 106 and Mobile Switching Center (MSC) 107. Traffic is controlled according to control information of a call control processor (CCP) 108. The voice data matching of the transcoding select bank (TSB) 105 receives and compresses the voice signal of a Pulse Code Modulator (PCM) from the MSC 107 to the base station (BTS) 106. And restore the compressed signal from the base station (BTS) 106 and send it to the MSC 107. The main functions of the call control processor (CCP) 108 are to control traffic to facilitate traffic processing, and to allocate and release selector / vocoder channels required for call service. In addition, it performs handoff control so that the traffic service is maintained while the subscriber is moving. In addition, data service including service option 2 (SO2), location registration of the subscriber, and authentication function are also performed. The base station manager (BSM) 109 is a sub station that is in charge of operation management and maintenance of the control station and the base station as a whole, including the base station controller (BSC) 112 and the base station (BTS) 106. System. To this end, when the system is started, information about initialization and system configuration are transmitted from the BSM 109 to the respective subsystems through the CCP 108, and the status information coming from each subsystem is collected and retrieved for various diagnostics. Perform the function. The MSC 107 is a mobile switch and is responsible for transferring authentication related data between the authentication center (AC) 110 and the control station in addition to basic call processing. AC 110 verifies all data related to authentication. The traffic control function to which the present invention is applied is performed in the BCP 102 which is a base station control apparatus. Also included is a Home Location Register 111.

2 is a diagram illustrating frequency channel allocation in a CDMA mobile communication system to which the present invention is applied.

That is, it can be used in one cell by dividing into several channel frequencies (f1, f2, f3 .....) 22 with a bandwidth of 1.25Mhz for a given frequency range 21. Each of the divided frequency channels requires a radio frequency (RF) and a power amplifier.

3 is a configuration diagram of a cell using multiple CDMA frequency channels.

As shown in FIG. 3, the CDMA channel f1 represents a primary CDMA channel, and the base stations of all cells must serve with the primary CDMA channel f1 in common. Depends on the traffic of the cell. That is, a base station of a local cell where traffic is basically expected to use a large number of CDMA channels, whereas a base station of a local cell where traffic is expected to be small serves with a small number of CDMA channels.

4 is an embodiment traffic control flow diagram for increasing soft hand-off for a data service in accordance with the present invention.

Some of the call channels that can be provided by the primary CDMA channel are reserved for error-sensitive data service traffic services only, so that if the total traffic is below the threshold, the call channel within the primary CDMA frequency channel is allocated to both voice and data services. If the total number of traffics is greater than or equal to the threshold, only data traffic is allocated to the primary CDMA channel to perform soft handoff. Voice traffic allocates talk channels other than the primary CDMA channel. When this algorithm is applied, the number of data traffic prioritized call channels is properly adjusted according to the data traffic environment, which can greatly increase the probability of soft handoff of data traffic, thereby greatly improving the quality of service.

First, upon receiving the outgoing message or paging response message from the mobile station MS (401), the base station (BTS) starts traffic control. First, the base station control processor (BCP) examines the radio resource state of the current base station (BTS) for radio resource allocation (402). That is, the channel usage is searched for and the usage state of the primary CDMA channel is examined (402).

As a result of the survey 402, the number of traffics in progress on the primary CDMA channel is subtracted from the maximum number of traffics available on the primary CDMA channel minus the number of talk channels reserved for priority in the data service, i.e., the threshold. 403, if less than the threshold, allocates the request call to the talk channel of the primary CDMA channel (408).

As a result of the comparison (403), if the total number of traffic allocated to the primary CDMA channel is greater than or equal to the threshold, it is determined whether the traffic type is voice or data (404), and in the case of voice traffic (405), unconditionally other than the primary channel. Is assigned to the frequency channel of (407). However, in the determination result 404, in case of data traffic (405), it is determined whether the primary CDMA channel is currently available (406), and if available, the call channel of the primary CDMA channel is allocated (408) at the time of handoff. If the primary CDMA channel is all in use and cannot be used (406), it allocates traffic to other frequency channels except the primary CDMA (407).

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

As described above, the present invention has a significant adverse effect on the quality of service in data traffic compared to voice traffic in which some packet loss is not a big problem during hard handoff in which a call is temporarily disconnected in a CDMA mobile communication system. In the base station using the CDMA channel of 1.25 MHz frequency band of the primary CDMA frequency band, a part of the call channel in the primary CDMA frequency band is given priority to data traffic compared to voice traffic to perform soft handoff during handoff, thereby processing error-sensitive data. Not only can it efficiently handle traffic, but it can also improve the quality of service.

Claims (4)

A traffic service control method in a code division multiple access (CDMA) mobile communication system, A first step of, upon receiving a call processing request, the CDMA base station searching the channel usage of the current base station for radio resource allocation and analyzing the usage state of the primary CDMA channel; As a result of the analysis of the first step, the number of ongoing traffic in the primary CDMA channel is a predetermined threshold (preferably, the number of call channel traffic reserved for priority to the data service at the maximum number of traffic that can be provided in the primary CDMA channel). A second step of retrieving the type of traffic currently requested for processing, and assigning the currently requested traffic to the call channel of the primary CDMA channel if less than a threshold value; A third step of unconditionally allocating to a frequency channel other than the primary CDMA channel for voice traffic and determining whether the primary CDMA channel is available for data traffic according to the traffic type search result of the second step; And As a result of the third step, if available, priority is given to the data traffic and assigned to the call channel of the primary CDMA channel, thereby reducing hand-to-frequency hard handoff by causing handoff between primary CDMA channels during handoff. The fourth step to perform a soft handoff and assign to a frequency channel other than the primary CDMA channel if not available Traffic service control method by soft handoff in a mobile communication system comprising a. The method of claim 1, A method for controlling traffic service by soft handoff in a mobile communication system, which allocates a reserved area for data traffic to a primary CDMA channel. delete In a control system having a processor for controlling traffic service by soft handoff, A first function of, upon receiving a call processing request, the CDMA base station searching the channel usage of the current base station for radio resource allocation and analyzing the usage state of the primary CDMA channel; As a result of the analysis of the first function, the number of ongoing traffic in the primary CDMA channel has a predetermined threshold (preferably, the number of call channel traffic reserved for priority to the data service at the maximum number of traffic that can be provided in the primary CDMA channel). A second function for retrieving the type of traffic currently required for processing if greater than or equal to, and for allocating the currently requested traffic to the call channel of the primary CDMA channel if less than a threshold; A third function for unconditionally assigning to a frequency channel other than the primary CDMA channel for voice traffic and determining whether the primary CDMA channel is available for data traffic according to the traffic type search result of the second function; And As a result of the determination of the third function, if available, priority is given to data traffic and assigned to the call channel of the primary CDMA channel, so that handoff occurs between primary CDMA channels during handoff, thereby reducing inter-frequency hard handoff. Fourth function to allow soft handoff and assign to a frequency channel other than the primary CDMA channel if not available A computer-readable recording medium having recorded thereon a program for realizing this.