KR20040098919A - Call process system and method for trunk line overload in mobile communication system - Google Patents

Abstract

PURPOSE: A call processing system when a trunk line is overloaded in a mobile a mobile communication system and a method therefor, particularly for controlling packet data requested by a subscriber according to a service grade priority level, are provided to guarantee reliable QoS(Quality of Service). CONSTITUTION: When a mobile station(400) requests call connection, a BSC(Base Station Controller)(200) senses whether a trunk line(270) is overloaded. If the trunk line(270) is overloaded, the BSC(200) discriminates packet data received from a PCN(Packet Core Network)(100) by pre-determined service grade and buffers it. And then, the BSC(200) discriminately extracts the buffered packet data according to a service grade, generates radio link protocol packet data that has been delayed for a predetermined time, and transmits it. A base station(300) matched to the BSC(200) and the trunk line(270) processes the request for call connection received from the mobile station(400) in a service area and manages channel resources for processing the request.

Description

CALL PROCESS SYSTEM AND METHOD FOR TRUNK LINE OVERLOAD IN MOBILE COMMUNICATION SYSTEM}

The present invention relates to a mobile communication system, and more particularly, in a mobile communication system for processing high-speed packet data traffic, by detecting whether an overload occurs in a relay line between a base station and a control station at a specific time when a call connection request of a mobile station occurs, Is determined by the service class determined by the priority of the subscriber who requested the packet data received from the Packet Core Network (PCN) and the priority of the type of service to be provided to the subscriber when it is detected that an overload has occurred. Buffering the received packet data, classifying and extracting the buffered packet data according to the service level, and generating and transmitting radio link protocol packet data delayed for a predetermined time, thereby overloading the relay line generated at a specific time period. Call out by distributing time zones for In a mobile communication system that relates to a call processing system and method of the trunk during the overload.

Currently, the mobile communication system is a system that provides voice-oriented services based on IS (Interim Standard) -95, such as high-speed packet data services such as International Mobile Telecommunication (IMT-2000) services, video services, and even packetized voice services. It is developing into a system supporting the same multimedia service.

A mobile communication system supporting such a multimedia service is based on a high speed packet data service, and a mobile communication system based on the high speed packet data service increases data transmission rate in a cell based on the capability of a corresponding system resource and provides data from a mobile station. Designed to be capable of allocating forward link resources to the mobile subscribers whenever service is required, the maximum data processing that can be processed in the cell to maintain a predetermined Frame Error Rate (FER) A limited resource is managed by scheduling by a method such as limiting a forward link capacity to transmit data with a capacity smaller than the capacity.

1 is a block diagram showing a simple configuration of a mobile communication system supporting a conventional high-speed packet data service, and includes a mobile station 10, a base station 11, a control station (BSC) / packet controller (PCF), and a base station controller / packet. Control Function (12), Switcher (MSC) / Visitor Location Register (VLR) (13), Packet Data Serving Node (PDSN) (14), Packet Core Network (PCN) (15) ) And the Internet network 16.

The base station 11 and the BSC / PCF 12 connect the mobile station 10 to the PDSN 14, and request the packet data service to receive the packet data service from the base station 11 to which the mobile station 10 is wirelessly connected. The BSC / PCF 12 then determines the PDSN 14 to send packet data.

Then, a radio traffic channel and a RLP link are established between the mobile station 10 and the BSC of the BSC / PCF 12, and the BSC of the BSC / PCF 12 is established. Between A and PCF, an A8 traffic link is established for carrying PPP link data between the mobile station 10 and the PDSN 14.

In addition, the MSC / VLR 13 is responsible for the overall management of the system such as subscriber information and billing information for each mobile station 10 and connected to other external communication networks (PSTN, PCS, PLMN, etc.) (not shown). The BSC / PCF 12 is connected to the PCN 15 and the internet network 16 through the PDSN 14 serving as an interface of packet data.

Meanwhile, a mobile communication system supporting multimedia services such as a high speed packet data service, a video service, and a packetized voice service generates a greater amount of traffic than that of a conventional voice service-oriented mobile communication system. The possibility that the relay line, which is a network component between the base station 11 and the control station 12, is increased.

In order to perform an immediate response process for the mobile station 10 having frequent service-off and overload and having a high service priority, that is, high quality of service (QoS), the existing voice service-oriented mobile communication is performed. It is necessary to reserve more resources than the system.

For example, the base station 11 of the mobile communication system manages channel resources for guaranteeing the service required by the mobile station 10 existing in its cell, and interoperates with higher system components 12-14. The service is performed through the scheduling process of allocating channel resources and bands by identifying the service characteristics of the call required by the mobile station 10.

In addition, the control station 12 receives the packet data requested by the mobile station 10 from the upper PCN 15 and transmits the packet data to the base station 11 using the radio link protocol.

At this time, the mobile communication system supporting the high-speed packet data service instantaneously processes a large amount of packet data, which is required from the mobile station 10 to more efficiently manage, utilize, and allocate available resources of the system. Each mobile station 10 is managed according to a given service class in consideration of the characteristics of the data call, that is, the priority of each subscriber or service.

That is, if a call connection to a service of a higher service level than that of an existing in-service call is required in the middle of performing a service for a specific mobile station 10, the available resource is used when available resources of the corresponding system are secured. The mobile station 10 accepts the service requested by the mobile station according to the newly requested service class.

However, if the available resources of the system are not secured, the service cannot be performed on the requested call at the source, or the service of a call having a service class lower than the service level of the requested call among the existing calls is suspended. And schedules the service of the newly established call instead.

In addition, when relay line congestion occurs due to the limited capacity of the relay line between the base station 11 and the control station 12 in the mobile communication system for processing high-speed data traffic, continuous relay line congestion may be performed through the scheduling method as described above. Although a call request from a mobile station having a high service class may be rejected, it may not guarantee a reliable quality of service (QoS) by subscriber or service.

On the other hand, when a relay line congestion occurs due to the limitation of the relay line capacity between the base station 11 and the control station 12 in the conventional mobile communication system for processing high-speed data traffic, the mobile communication system accepts a new call according to the relay line load. A method of determining whether or not is described with reference to the flowchart of FIG. 2 as follows.

The base station 11 in the mobile communication system always determines whether a new call request for data service is received from the new mobile station 10 during the initial operation of the system or during service (S20), wherein the mobile station 10 itself The data service request is made without knowing the current available resource situation of the accessing system.

When a new call connection request is received from the mobile station 10, the upper end that manages the subscriber information of the mobile station 400, such as the MSC / VLR 13, requests the call connection according to the subscriber information for the mobile station 10. The priority of the mobile station 10 and the priority of the service registered by the subscriber of the mobile station 10 are checked (S21, S22), and the checked priority of the mobile station 10 and the priority of the service. Accordingly, the service grade for the new call requested by the mobile station 10 is determined (S23).

Here, as a method of determining the priority of the mobile station 10 by a higher level managing subscriber information of the mobile station 400, such as the MSC / VLR 13, the mobile station 10 uses a specific service or provides a relative service. There are various methods such as determining the service class by checking whether it is a mobile station 10 using high quality service, that is, high quality of service (QoS) or a mobile station 10 delivering emergency situation by paying an expensive fee. Can be used.

In addition, the upper end of managing the subscriber information of the mobile station 400, such as the MSC / VLR 13, the mobile station 10 in consideration of the characteristics of the application service and the packet data transmission rate required by the mobile station 10, etc. The service priority of the call may be checked, or the service level of the requested call may be finally determined in consideration of all the priorities identified through the above process.

In addition, when a change occurs in the service grade determined in the step S23, the upper end of managing subscriber information of the mobile station 400, such as the MSC / VLR 13, is the priority of the mobile station 10 and the corresponding mobile station. In consideration of the priority of the service requested by (10), the changed information is reset and stored in a separate storage means (not shown) which stores a database of service grades of various calls requested from the mobile station 10 (not shown). S24).

Then, the BSC / PCF 12 of the system calculates the resources needed to satisfy the determined service class of the call, checks the amount of available resources of the base station 11, and then accepts the requested call connection request. It is determined whether or not (S25, S26).

Here, there may be various ways for the system to accept a new call connection and perform a service for a new call requested from the mobile station 10 according to the service class. For example, the relay line congestion situation does not occur in the above step. If it is determined that the amount of available resources can perform the service according to the call request, the service is started for the requested new call, and if the relay line congestion occurs even if the base station 11 has available resources, the requested new A method of refusing to accept a call, performing a service on behalf of a lower level of service quality that does not satisfy the service level, or performing a service on the requested new call while degrading the service quality of existing in-service calls; There is this.

In another example, in the step S26, when a relay line congestion occurs and the connection of the new call cannot be accepted, the mobile communication system checks the call status of the current service and the service priority of the newly requested call is the current service. If it is determined that it is higher than the service priority of the in-progress call (S27, S28), it is determined whether the system can transmit a pause message to the existing in-service call and transmits a call stop message (S29), and the service of the newly requested call There is a method of performing a call acceptance and service initiation procedure according to the class (S30).

Then, certain calls among existing in-service calls are suspended, and service is started for new calls of higher service level.

In the step S28, when the call in service cannot be stopped, the connection request of the new call is rejected (S31).

In the above process, when a relay line congestion occurs, a method for accepting a new call and starting a service is explained. However, even when a request for connection of a new line is not received, loss of the radio link protocol packet in the relay line section occurs when the relay line congestion occurs. This occurs and degrades the service quality of existing in-service calls.

Accordingly, in the conventional technology as described above, when the relay line is overloaded due to the limited capacity of the relay line between the base station and the control station in the mobile communication system for processing high-speed data traffic, a new call request of a mobile station having a high service grade is made. By rejecting or lowering the quality of service of existing in-service calls for new call access, there is a problem in that it cannot guarantee reliable quality of service (QoS) by subscriber or service.

In addition, in view of the above problems, if some portion of the relay line resources between the base station and the control station is reserved, the system performance is degraded because the relay line resources between the base station and the control station are not effectively utilized, and the relay line extension of the corresponding system is prevented to prevent the relay line runaway. If you take the problem that the economic burden increases.

Accordingly, the present invention has been proposed to solve the above-described problems, and in a mobile communication system for processing high-speed packet data traffic, an overload occurs in a relay line between a base station and a control station at a specific time when a call connection request of a mobile station occurs. Service class determined by the priority of the subscriber who requested the packet data received from the packet core network (PCN) and the type of service to be provided to the subscriber when it is detected that the relay line is overloaded. By buffering the received packet data according to the determined service class, extracting the extracted packet data according to the service class, and generating and transmitting radio link protocol packet data delayed for a predetermined time. Overload of the repeater It is an object of the present invention to provide a system and a method for distributing time zones to handle calls.

1 is a block diagram showing a simple configuration of a mobile communication system supporting a conventional high speed packet data service.

2 is a flowchart illustrating a process of determining whether to accept a new call according to a relay line load in a mobile communication system supporting a conventional high speed packet data service.

Figure 3 is a block diagram showing the configuration of a call processing system when relay line overload in the mobile communication system of the present invention.

Figure 4 is a flow chart showing the operation of the call processing method when the relay line overload in the mobile communication system of the present invention.

*** Description of the symbols for the main parts of the drawings ***

100: PCN 200: control station

210: input buffer 220: priority comparison unit

230 to 233: priority buffer 240: switch array

250: RLP packet processing unit 260: RLP packet transmission unit

270 relay line 280 repeater load measurement unit

290: control unit 300: base station

310: channel card 400: mobile station

In order to achieve the above object, the present invention provides a mobile communication system for processing high-speed packet data traffic. When overload is detected on a relay line connected to a base station when a call connection request of a mobile station is performed, the received packet data is classified by service class. And after the buffering, a control station which processes the call by extracting the buffered packet data according to the priority according to the class of service.

In addition, the present invention provides a mobile communication system for processing high-speed packet data traffic, comprising the steps of: receiving a service class for the requested new call when the mobile station requests a new call connection; Detecting whether a relay line is overloaded and buffering packet data received from a packet core network (PCN) according to the service class when the relay line is detected to be overloaded; And classifying and extracting the buffered packet data according to a service level, and then generating radio link protocol packet data from the extracted packet data to perform data service.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram showing the configuration of a call processing system in case of a relay line overload in the mobile communication system of the present invention. As shown in FIG. 3, a call connection of a mobile station 400 in a mobile communication system processing high-speed packet data traffic is shown. Detects whether the relay line 270 is overloaded when requested, and if it is detected that the relay line 270 is overloaded, the priority of the subscriber who requested the packet data received from the packet core network (PCN) 100 and the subscriber. According to the service class determined by the priority of the type of service to be provided, the received packet data is buffered by classifying the determined service class, and the buffered packet data is classified and extracted according to the service class for a predetermined time. A control station (Base Station Controller, BSC) 200 for generating and transmitting delayed radio link protocol packet data; The base station 300, which is matched by the control station 200 and the relay line 270, manages the call connection request from the mobile station 400 in the service area and manages channel resources for the processing.

In addition, the control station 200 stores the packet data received from the packet core network (PCN) 100 according to the input order, and the control station 200 according to the service class determined for the call requiring the connection. Priority comparison unit 220 that compares the service priority of the packet data output from the input buffer 210 and the packet data divided by the service class from the priority comparison unit 220 is classified and buffered by the corresponding service class A plurality of priority buffers 230 to 233, a switch array 240 for sequentially extracting packet data buffered in the plurality of priority buffers 230 to 233 according to a service level, and the switch array RLP (Radio Link Protocol) packet processing unit 250 for generating radio link protocol packet data from the packet data extracted through the 240 and the RLP packet processing unit 250 Matches the RLP packet transmitter 260 for transmitting the received radio link protocol packet data to the channel card 310 of the base station 300, and the channel card 310 of the RLP packet transmitter 260 and the base station 300. A relay line 270 for transmitting the radio link protocol packet data, a relay line load measuring unit 280 for detecting and periodically reporting whether the relay line 270 is overloaded and measuring a loss rate of the radio link protocol packet data; In addition to the overall control for the generation and processing of the link protocol packet data, the priority comparison unit 220, a plurality of priorities depending on whether the relay line 270 is overloaded from the relay line load measurement unit 280 The control unit 290 controls the ranking buffers 230 to 233 and the switch array 240.

Here, in the present invention, the plurality of priority buffers 230 to 233 separately storing packet data classified by service class may be configured using a software buffer or a hardware buffer, and the switch array 240 may be a pointing function. It can be configured using a software method using or a hardware switch array.

In order to prevent the generation of the radio link protocol packet data of the control station 200 and the deterioration of processing performance, when the relay line 270 overload between the base station 300 and the control station 200 does not occur, the control station ( The control unit 290 in the 200 controls the priority comparison unit 220, the plurality of priority buffers 230 to 233, and the switch array 240 to be in an inactive state, thereby controlling the packet data received from the PCN 100. The RLP packet processing unit 25 and the RLP packet transmission unit 260 generate and transmit radio link protocol packet data immediately after storing the data in the input buffer 210, so that existing in-service calls are overloaded when the relay line 270 is overloaded. It is possible to minimize the influence of the performance degradation of the control station 200 caused by the call processing.

On the other hand, referring to the flowchart of Figure 4 attached to the operation of the present invention, first, a new call from a specific mobile station 400 while the base station 300 services a plurality of mobile stations (not shown) in the service area; When the access request is received (S40), the upper end of managing the subscriber information of the mobile station 400, such as the MSC / VLR 13 of Figure 1, the service according to the subscriber priority and the type of service requested by the mobile station 400 Whether the mobile station 400 requesting the new call connection is a mobile station 400 that is provided with a specific service or is assigned a high quality of service (QoS) paying an expensive fee. In step S41, the service class is determined according to the identified mobile station and priority of the service.

In addition, when a change occurs in the determined service class, the upper end of managing subscriber information of the mobile station 400, such as the MSC / VLR 13, has priority of the mobile station 400 and the mobile station 400. In consideration of the priority of the requested service, the changed information is stored in a separate storage means (not shown) for storing a database of service grades of various calls requested from the mobile station 400 (S41).

At this time, the priority comparison unit 220 in the control station 200 receives the service grade stored in the separate storage means (not shown) (S42), the input buffer 210 in the control station 200 is PCN ( Packet core network) 100 stores the packet data received in the order of input (S43).

Here, when the control station 200 receives a new call connection request from the PCN 100, the control station 200 inquires whether the available channel resources exist or not, and the base station 300 receives the inquiry. In the case of serving a plurality of mobile stations, it checks whether there are available channel resources that can accommodate the call connection of a specific mobile station 400 that has newly requested data service, reports to the control station 200, and reports limited channel resources. Will be managed.

In addition, the control station 200 performs call processing according to the presence or absence of available channel resources received from the base station 300, or the current base station 300 and the control station 200 from the relay line load measuring unit 280. Intermediate relay line 270 is periodically reported whether or not the overload state to perform the call processing during overload.

Here, the relay line 270 matches the RLP packet transmitter 260 in the control station 200 with the channel card 310 of the base station 300 and transmits the radio link protocol packet data. 280 serves to detect whether the relay line 270 is overloaded according to a loss rate result measured through a CRC (Cyclic Redundancy Check) test of the radio link protocol packet data, and the relay line load measuring unit 280 controls It is installed in the station 200 or the base station 300.

The relay line load measuring unit 280 measures the loss of the radio link protocol packet data or the ATM cell loss rate of the relay line section generated when the relay line 270 transmits the packet data between the base station 300 and the control station 200. You can determine the overload condition.

In this case, when there is no channel resource available in the base station 300, the call connection request of the mobile station 400 that has newly requested a call connection is not accepted, but there are channel resources available in the base station 300. If the relay line 270 between the base station 300 and the control station 200 is not overloaded (S44), the control station 200 normally responds to the new call connection request of the mobile station 400 and accepts the call. And transmitting the packet data received from the PCN 100 as the radio link protocol packet data through the base station 300 to the mobile station 400 by performing a resource allocation procedure (S47, S48).

That is, under the control of the controller 290 for generating and processing radio link protocol packet data, the packet data received from the PCN 100 and sequentially stored in the input buffer 210 is RLP (Radio Link Protocol) packet processing unit ( When the RLP packet transmission unit 260 matches the RLP packet transmission unit 260 with the channel card 310 of the base station 300 when the RLP packet transmission unit 260 converts the radio link protocol packet data into the data, the RLP packet transmission unit 260 matches the radio link protocol packet data. The base station 300 is transmitted to the base station 300 through the relay line 270, and the base station 300 wirelessly transmits it to the mobile station 400.

On the other hand, in the step (S44), when a large amount of packet data is generated in a specific time zone and the relay line 270, which is a network component between the base station 300 and the control station 200 is overloaded, the relay line load measuring unit ( 280 measures the loss rate of the radio link protocol packet data, detects whether the relay line 270 is overloaded, and reports the overload state to the controller 290.

Accordingly, the priority comparison unit 220 is responsible for overall control for generating and processing radio link protocol packet data, and depending on whether the relay line 270 is overloaded from the relay line load measurement unit 280. The control unit 290, which controls the plurality of priority buffers 230 to 233 and the switch array 240, reports the priority comparison unit 220 and the plurality of priorities according to the report that the relay line 270 is overloaded. The buffers 230 to 233 and the switch array 240 are controlled to be activated.

First, the priority comparison unit 220 receives a service grade determined by the base station 300 in step S42 and stored in a separate storage means (not shown), and according to the received service grade, an input buffer ( After comparing the service priorities of the packet data output from 210, the service data is classified into service classes and output to the plurality of priority buffers 230 to 233. FIG.

Then, the plurality of priority buffers 230 to 233 buffer the packet data classified by the service class from the priority comparator 220 by the service class (S45), and the switch array 240 The packet data buffered in the plurality of priority buffers 230 to 233 is again classified according to the service level, sequentially extracted, and output to the RLP packet processor 250 (S46).

In addition, the RLP packet processing unit 250 generates radio link protocol packet data from the extracted packet data (S47), and through the RLP packet transmission unit 260 and the relay line 270, the channel card of the base station 300 ( 310, and the channel card 310 of the base station 300 initiates a data service for wirelessly transmitting it to the mobile station 400 (S48).

In the present invention, the packet data received from the PCN 100 is temporarily stored in the input buffer 210, the packet data according to the service grade previously stored in a separate storage means (not shown) in the priority comparison unit 220 The service priority is determined and buffered according to the service class in the plurality of priority buffers 230 to 233 according to the determination result.

In addition, the control station 200 transfers the packet data received from the PCN 100 to the corresponding base station 300 in the input order to prioritize the quality of service (QoS) for the packet data requested by the mobile station 400. Uncontrollable phenomena can be eliminated.

For example, the first priority buffer 230 buffers the packet data having the highest quality of service (QoS), and the second priority buffer 231 buffers the packet data having the next quality of service. The packet data is classified and buffered for each service class in the plurality of priority buffers 230 to 233.

Then, the switch array 240 sequentially extracts the packet data buffered in the plurality of priority buffers 230 to 233 according to the service grade, and the switch array 240 may include the plurality of priority buffers ( The first priority buffer 230 buffering the packet data having the highest service grade in consideration of the channel resources that can be processed simultaneously by the control station 200 or the corresponding base station 300 when extracting the packet data from 230 to 233. To the n-th priority buffer 233 buffering the packet data having the lowest service grade, the number of packet data to be extracted is differentially extracted.

That is, after the priority buffers 230 to 233 are differentiated from a high service grade to a predetermined ratio, when the packet data is extracted, 'five' packet data is extracted from the first priority buffer 230. In this case, packets are sequentially extracted by extracting 'four' packet data from the second priority buffer 231 and then extracting 'three' packet data from the third priority buffer 232. The data will be extracted.

Here, packets stored in the plurality of priority buffers 230 to 233 according to the service quality priority policy and the charging policy of the operator or according to the priority of the service class assigned to the plurality of priority buffers 230 to 233. The operation method of the switch array 240 for extracting the data may be applied to a method of changing the amount of packet data to be extracted in consideration of channel resources that can be processed by the control station 200 or the corresponding base station 300.

Therefore, after the packet data extracted from the switch array 240 is first received from the PCN 100, a predetermined time delay occurs while passing through the plurality of priority buffers 230 to 233 and the switch array 240. Since it is transmitted to the RLP packet processing unit 250, the call is distributed by distributing the time zones to the overload of the relay line generated in a specific time zone, and the base station 300 and the control station by the instantaneous massive packet data generated at the specific time zone. It is to prevent the overload is continuously generated in the relay line 270 that is a network component between (200).

The predetermined time delay adjusts the performance of the plurality of priority buffers 230 to 233 and the switch array 240 according to the performance and the degree of overload of the entire system to adjust the length of the delayed time.

As described above, the present invention, in the mobile communication system for processing high-speed packet data traffic, when the call connection request of the mobile station detects whether the relay line between the base station and the control station is overloaded at a specific time period, the relay line is overloaded Is classified by the determined service class according to the service class determined by the priority of the subscriber who requested the packet data received from the packet core network (PCN) and the priority of the type of service to be provided to the subscriber. Buffering the received packet data, classifying and extracting the buffered packet data according to service level, and generating and transmitting radio link protocol packet data delayed for a predetermined time, thereby overloading the relay line generated at a specific time period. Distribute time zones to handle calls, Accordingly, the packet data received through the PCN is rearranged according to the priority of the determined service class and transmitted to the channel card of the corresponding base station, thereby controlling the packet data requested by the subscriber according to the service class priority. There is an effect that enables the guarantee of quality (QoS).

Claims (9)

In a mobile communication system for processing high-speed packet data traffic, if an overload is detected on a relay line connected to a base station when a call connection request is made by a mobile station, the received packet data is classified and buffered according to service class, and then priority is given by the service class. And a control station which processes the call by extracting the buffered packet data according to the control. 2. The apparatus of claim 1, wherein the control station comprises: an input buffer for storing packet data received from the PCN in an input order; A priority comparison unit for comparing service priorities of the packet data output from the input buffer according to the service class determined for the call requiring the connection; A plurality of priority buffers for dividing and buffering packet data classified for each service class from the priority comparison unit for each service class; A switch array configured to sequentially extract packet data buffered in the plurality of priority buffers according to a service class; Responsible for the overall control for generating the radio link protocol packet data through the RLP packet processor and the RLP packet transmitter after the packet data extracted through the switch array is transmitted to the channel card of the base station through the relay line. Of course, the relay line overload in the mobile communication system, characterized in that it comprises a control unit for controlling the priority comparison unit, a plurality of priority buffers and the switch array according to whether the relay line is reported from the load load measurement unit City call processing system. 3. The call processing system of claim 2, wherein the plurality of priority buffers are configured using a software buffer or a hardware buffer. The call processing system according to claim 2, wherein the switch array is configured by using a software method or a hardware switch array using a pointing function. The relay line of claim 2, wherein the controller controls the priority comparator, the plurality of priority buffers, and the switch array in an inactive state when the relay line overload does not occur between the base station and the control station. Call processing system in case of overload. A mobile communication system for processing high-speed packet data traffic, comprising: receiving a class of service for a requested new call when the mobile station requests a new call connection; Detecting whether a relay line is overloaded and buffering packet data received from a packet core network (PCN) according to the service class when the relay line is detected to be overloaded; Extracting the buffered packet data according to a service class, and then generating radio link protocol packet data from the extracted packet data to perform a data service. Call processing method. The method of claim 6, wherein the buffering of the received packet data by service class comprises: receiving a service class determined for a call for which a connection is requested, and outputting packet data output from an input buffer according to the received service class. Comparing the service priorities of; And dividing the packet data by service class and buffering the plurality of buffers according to the comparison result according to the comparison result. The mobile communication system of claim 6, wherein the extracted packet data is sequentially extracted in consideration of the amount of channel resources that can be processed simultaneously, with a difference in the number of packet data extracted for each service class. Call handling method in case of relay line overload. The call processing method according to claim 6, wherein the radio link protocol packet data is packet data generated by a predetermined time delay from packet data initially received from the PCN. .