KR20080096192A - Apparatus and method for traffic control among switching entities in all ip network - Google Patents

Abstract

An apparatus and a method for controlling traffic among switching entities in all IP network are provided to prevent the interrupt of a service caused by compulsorily reducing traffic by linking some BS(Base Station)s generating overload with different SE(Switching Entity) when generating overload traffic. Traffic information is received from corresponding BSs(400). Traffic information is collected from the BSs and the total amount of traffic is calculated(402). If the total traffic is greater than critical value, a base station transmitting the greatest traffic is selected and a priority is assigned(410). It determines whether the base station assigned the priority is capable of linking with arbitrary SE. The arbitrary SE determines whether to process the traffic of the BS acquiring the priority.

Description

Traffic control device and method between switching entities in all IP communication system {APPARATUS AND METHOD FOR TRAFFIC CONTROL AMONG SWITCHING ENTITIES IN ALL IP NETWORK}

1 is a block diagram of a general mobile communication system;

2 is a traffic control flowchart in a mobile communication system;

3 is a conceptual diagram of an All IP based Cognitive Network according to an embodiment of the present invention;

4 is a flowchart illustrating an operation of a switching entity (SE) for controlling traffic between switching entities in an All IP communication system according to an embodiment of the present invention;

5 is a SE device for traffic control between switching entities in the All IP communication system according to an embodiment of the present invention;

6 is a simulation result graph according to an embodiment of the present invention.

The present invention relates to an apparatus and method for controlling traffic between switching entities (hereinafter, referred to as "SE") in an all IP communication system. In particular, when an overload traffic occurs in the SE controlling base stations (BSs), the overload traffic occurs. The present invention relates to a traffic control apparatus and method for linking some BSs generating another BS to another SE.

Referring to the general mobile communication system configuration diagram in Figure 1, the system is controlled by the MSC (Mobile Switching Center) (104,104_n) is connected to a plurality of BS (Base Station) (108 ~ 124) by a fixed link to transmit and receive information It is structured to. Each of the BSs 108 to 124 (except the MS 116) transmits and receives data through a wireless interface with mobile stations (MSs) in a serving cell. For example, when there is an MS 116 in a cell of the BS 114, the BS 114 receives and forwards the information of the MS 116 to the MSC 104, where the MSC 104 The MS 116 information from the BS 114 is stored in the Visitor Location Register (VLR) 106 according to a registration procedure. In this case, when the MS 116 moves out of the MSC 104 controlling the BS 114 to the BS 120 controlled by another MSC 104_n, an inter-MSC handoff occurs. 116 transmits its information to the MSC 104_n through the BS 120 to perform location registration. Upon registration of the location, the MSC 104_n stores the information of the MS 116 in the VLR 106_n. In the handoff between the MSCs, the handoff between the MSCs 104 and 104_n is handled in a hardware manner by the Public Switched Telephone Network (PSTN) 100 that controls the MSCs 104 and 104_n. The HLR 102 is a core system that is indispensable in mobile communication. The HLR 102 is a database system that stores and manages location and status information of a terminal and provides the same to a system that requires the information. That is, the user's mobility is the biggest feature that distinguishes wired telephones from mobile communications.

In the existing mobile communication system structure, when all the systems are connected by wire except for the transmission interval between BS and MS, if a large amount of data is transmitted from multiple MSs at once, the MSC becomes overloaded. Degrading the performance, MSCs and BSs each have a fixed capacity. The MSC is responsible for the overall traffic management for the BS. When an overload occurs, the MSC controls traffic by exchanging control messages with the BS. Referring to Figure 2 showing a traffic control flow chart will be described traffic control when the MSC is overloaded.

Referring to FIG. 2 (a), when the amount of data transmitted by the BS is momentarily increased and an overload occurs, the MSC 200 indicates in step 204 that OVERLOAD MESSAGES indicating that the current traffic has been exceeded or Send SIGNALING POINT CONGESTED INFORMATION MESSAGES to BS 202. At this time, when the BS 202 receives the message OVERLOAD MESSAGES, the BS 202 simultaneously operates the T5 206 and T6 208 timers to reduce traffic exceeding the capacity of the MSC 200. And T6 is a timer that is operated at the MSC. To prevent them. After the T5 206 timer completes, the traffic load of BS 202 that substantially exceeds the MSC 200 capacity at the T6 208 timer time in operation decreases. The traffic load is reduced until the predetermined traffic level is reduced. When the T6 206 timer expires, the BS 202 transmits an OVERLOAD MESSAGES or SIGNALING POINT CONGESTED INFORMATION ACK to the MSC 200 in step 210.

FIG. 2 (b) is a flowchart when the traffic of the BS 202 does not decrease despite the overload traffic control in FIG. 2 (a). If the traffic is increased even though 204 is received, the T6 timer 209 resumes operation so that the overload traffic of the MSC 200 continues to decrease.

As described above, in order to reduce the overload of the MSC, increased traffic of BSs in a mobile communication system must be forcibly reduced. This may cause new user registration to the MSC to be rejected. This is because the capacity of the MSs managed by the BS must be limited in order not to exceed the capacity of the limited MSC. That is, by reducing the traffic of the MS in service or new user MSs when the MSC traffic is exceeded. User MSs do not receive the desired service, resulting in poor service satisfaction. In particular, when the traffic of the MSC is exceeded, handoff of existing user MSs and subsequent registration cannot be guaranteed.

Accordingly, there is a need for a traffic control apparatus and method capable of preventing service interruption due to forced traffic reduction and ensuring handoff of an existing user terminal when an MSC overload occurs.

Accordingly, an object of the present invention is to provide an apparatus and method for controlling traffic in an All IP based communication system.

Another object of the present invention is to provide a traffic control apparatus and method which can prevent service interruption due to forced traffic reduction and guarantee handoff of an existing user terminal in an MSC overload in an All IP based communication system.

Another object of the present invention is to provide an apparatus and method for switching control to another MSC when an MSC overload occurs in an All IP based communication system.

) 양을 계산하는 과정과, 상기 총 트래픽(

)이 기설정된 임계치(

)보다 클 시, 최대 트래픽을 전송하는 기지국을 선택하여 우선순위(priority)를 부여하는 과정과, 상기 우선순위를 부여받은 기지국이 임의의 SE로 링크연결이 가능한지를 판단하여 링크연결을 하는 과정을 포함하는 것을 특징으로 한다.According to a first aspect of the present invention for achieving the above object, in a switching entity (SE) traffic control method in an All IP-based communication system, the total traffic (collecting and controlling the traffic information from the base stations)

) And the total traffic (

) Is the preset threshold (

Greater than), selecting a base station transmitting the maximum traffic and assigning priority to the base station transmitting the maximum traffic; It is characterized by including.

) 양을 계산하는 트래픽 관리부와, 상기 총 트래픽(

)이 기설정된 임계치(

)보다 클 시, 최대 트래픽을 전송하는 기지국을 선택하여 우선순위(priority)를 부여하는 BS 선택부와, 상기 우선순위를 부여받은 기지국이 임의의 SE로 링크연결이 가능한지를 판단하는 트래픽 전환 확인부를 포함하는 것을 특징으로 한다.According to a second aspect of the present invention for achieving the above object, in the All Entity based traffic control device (Switching Entity (SE)) traffic control apparatus, the total traffic (collecting and controlling the traffic information from the base stations)

A traffic management unit for calculating an amount, and the total traffic (

) Is the preset threshold (

Greater than), the BS selection unit which selects a base station transmitting the maximum traffic and gives priority to it, and a traffic switching confirmation unit determining whether the priority base station can link to any SE. It is characterized by including.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed descriptions of related well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Hereinafter, the present invention links some BSs that generate the overload to another SE when overload traffic occurs in a switching entity (hereinafter referred to as "SE") that controls the base stations (BSs) in the All IP communication system. An apparatus and method for controlling traffic between switching entities that make a connection will be described.

The limitation of the system mentioned in the prior art is due to the fact that data transmission and reception operates within a limited system between the BS and the MSC. However, in order to solve this problem, it is assumed in the present invention that the system is operated based on the All-IP network so that the integrated system operation is performed between the BS and the existing MSCs. Based on the All-IP network, the system transmits traffic using an IP address, so that MSCs will be constructed with a switching entity (SSE), which is smaller than the size, to manage capacity. .

3 illustrates an example of traffic control in an All-IP based communication system according to an embodiment of the present invention.

Referring to Figure 3 (a), SE (300 ~ 304) is an exchange that provides circuit and packet switching services to the MSs in conjunction with the All-IP based network 306. Switch traffic of user MSs between different SEs in the same or different networks. In addition to the present invention, the SEs 300 to 304 manage traffic of the BSs 308 to 312 through the All-IP based network 306. In fourth generation communication systems, many users will require large traffic for multimedia services. If the MSs mainly use voice-oriented services in some BS areas and multimedia services in some BS areas, the variation of traffic to be managed in the SE will be increased. That is, if the voice-oriented service is provided in the BS (310,312) area, and the multimedia service is performed in the BS 308 area, due to the traffic generated in the BS 308 area due to traffic overload in the SE 1 (304) The MSs may not be served or the service may be interrupted. At this time, when the traffic from the BS (308 ~ 312) is accepted above the predetermined threshold (SE 1 304) assumes that the SE 1 (304) controls the BS (308 ~ 312), The SE 3 300 that processes the traffic and the BS 308 that generate a lot of traffic are selected to form a link for the SE 3 300 to control the BS 308. b) by switching the link connection between the BS 308 and the SE 1 304 to a link connection between the BS 308 and the SE 3 300 that is handling the least traffic. Overload traffic of 304 can be maintained without service interruption.

The BSs 308 to 312 form a wireless path directly with the MSs to format signals for the wireless link to the wired link or the wired link to the wireless link, and measure the received electric field strength of the MS. Provide to SE.

4 is a flowchart illustrating an operation of an SE in an All IP based communication system according to an embodiment of the present invention.

Referring to FIG. 4, the SE collects traffic information periodically (or in an event manner) from BSs controlled by the SE in step 400. For example, in FIG. 3, SE 1 304 requests periodic information to collect traffic information periodically from BSs 308 to 312.

)을 각각 계산한다.Thereafter, the SE proceeds to step 402 and uses the traffic information from the BSs to sum the traffic currently being accommodated by the BS as shown in Equation 1 below.

Calculate each).

은 m 번째 SE이 n 번째 BS로부터 수용하는 트래픽 양이다.Where m is the index of SE, n is the index of BS under SE control, N is the number of BS under SE control,

Is the amount of traffic that the mth SE accepts from the nth BS.

)이 기설정된 임계치(

)보다 큰지 비교하여 작을 시, 상기 SE는 상기 400 단계로 진행하여 트래픽 정보를 상기 BS들로부터 계속 수집한다. 반면, 상기 BS들로부터의 총 트래픽(

)이 기설정된 임계치(

)보다 클 시, 406 단계로 진행하여 트래픽 크기(

) 순서대로 All IP 네트워크와 연동하는 SE들을 정렬(sorting)하여 최소 트래픽을 갖는 SE를 선택한다. 여기서, SE들을 트래픽 크기에 따라 정렬을 하기 위해, 상기 SE는 서로 자신들이 제어는 총 트래픽 정보를 공유하여 상기 SE가 정렬을 수행할 수 있다. 경우에 따라, 상기 네트워크 엔티티로 총 트래픽 정보를 전송하여 상기 네트워크 엔티티가 정렬을 수행하여 해당 SE로 최소 트래픽을 갖는 SE 정보를 전달할 수도 있다.Thereafter, the SE proceeds to step 404 where the total traffic (accepted by the SE) is accepted.

) Is the preset threshold (

If smaller than), the SE proceeds to step 400 and continues to collect traffic information from the BSs. On the other hand, the total traffic from the BSs (

) Is the preset threshold (

Greater than), proceed to step 406 to determine the traffic volume (

In order, select the SE with the minimum traffic by sorting the SEs interworking with the All IP network. Here, in order to sort the SEs according to the traffic size, the SEs share the total traffic information that they control with each other so that the SE may perform the sorting. In some cases, the total traffic information may be transmitted to the network entity, and the network entity may perform alignment to deliver SE information having minimum traffic to the corresponding SE.

Thereafter, the SE proceeds to step 408 to arrange BSs in order of traffic size using the traffic information from the BSs they control.

Thereafter, the SE gives priority to the BS having the highest traffic among the BSs arranged in the order of traffic size in step 410 to move to another SE having the least traffic. For example, in FIG. 3, when SE 1 304 is overloaded, the SE 1 304 selects SE 3 that receives less traffic among SEs 2 and 3, and controls its BS ( Priority is given to BS 308 which generates the most traffic among 308-312.

Thereafter, the SE checks whether the SE controlling the minimum traffic can receive the overload traffic in steps 412 to 414, and links the BS having the maximum traffic to the SE controlling the minimum traffic. Check to see if you are still overloaded after trying.

)와 우선순위를 부여받은 BS(

) 사이의 트래픽을 비교하여, 최소 트래픽을 제어하고 있는 SE가 트래픽을 전달받을 수 있는 상황인지를 판단할 수 있다. 상기

가

보다 클 시, 414 단계로 진행한다, 그리고, 상기

가

보다 작을 시, 418 단계로 진행하여 상기 408 단계에서 정렬된 BS 집합에서 우선순위를 부여받은 BS를 제외한 후, 상기 408 단계 내지 상기 412 단계를 반복 수행한다. 상기 반복수행은 최소의 트래픽을 제어하고 있는 SE에서 수용할 수 있는 과부하 트래픽을 발생하는 BS를 선택하기 위해 수행된다. 여기서, 상기

는 하기 <수학식 2>를 이용하여 계산한다.That is, in step 412, the SE has a margin of space in which another SE having the minimum traffic can receive traffic from the SE in which other excess traffic has occurred.

) And the prioritized BS (

By comparing the traffic between), it is possible to determine whether the SE controlling the minimum traffic can receive the traffic. remind

end

If greater, proceed to step 414, and

end

If smaller, the process proceeds to step 418 to exclude the BS given priority from the BS set arranged in step 408, and then repeats steps 408 to 412. The repetition is performed to select the BS generating overload traffic that can be accommodated in the SE controlling the minimum traffic. Where

Is calculated using Equation 2 below.

는 최소 트래픽을 수용하고 있는 SE가 과부하 트래픽을 받아들일 수 있는 트래픽 양이고, 상기

는 트래픽을 전달받는 SE의 임계치이고, 상기

는 최소의 트래픽을 수용하고 있는 SE에서의 트래픽 양이다.Where

Is the amount of traffic that the SE that is accepting the minimum traffic can accept the overloaded traffic,

Is the threshold of the SE receiving traffic, and

Is the amount of traffic in the SE that is accepting the least traffic.

) 상기 418 단계로 진행하여 상기 408 단계에서 정렬된 BS 집합에서 우선순위를 부여받은 BS를 제외한 후, 상기 408 단계 내지 상기 412 단계를 반복 수행한다. 상기 반복수행은 다음 우선순위를 갖는 BS를 선택하여 다른 SE로 링크 연결을 시도할시 과부하 트래픽을 발생시키지 않는 BS를 찾기 위해 수행된다. 상기

은 하기 <수학식 3>를 이용하여 계산한다.Subsequently, the SE determines whether overload traffic continues to occur in the SE even after linking the BS having the maximum traffic, which has been prioritized in step 414, to another SE.

In step 418, the BS is given priority to the BS set arranged in step 408, and then steps 408 to 412 are repeated. The repetition is performed to find a BS that does not generate overload traffic when attempting to link to another SE by selecting a BS having the next priority. remind

Is calculated using Equation 3 below.

는 다른 SE로 분산시킬 트래픽 양, 상기

는 트래픽을 전달하는 SE의 임계치이고, 상기

는 현재 제어하고 있는 트래픽 총량이다.Where

Is the amount of traffic to be distributed to other SEs,

Is the threshold of the SE that carries the traffic, and

Is the total amount of traffic currently being controlled.

), 416 단계로 진행하여 과부하 트래픽이 발생한 SE에서 상기 412 단계 내지 상기 414 단계를 만족하는 BS을 최소 트래픽을 제어하는 SE로 링크를 연결한다. On the other hand, if the overload traffic does not continue to occur in the SE (

In step 416, the BS that satisfies the steps 412 to 414 is connected to the SE that controls the minimum traffic in the SE where the overload traffic occurs.

At this time, in order to prevent the traffic transmitted from the system from being ping-pong to the original system, an overload traffic is generated so that a part of the overload traffic is received rather than the threshold of the SE that needs to deliver the BS traffic. Should be set lower than the threshold.

For example, in FIG. 3, SE 1 (SE controlling overload traffic) links BS 308 to SE 3 (SE controlling minimum traffic) to distribute overload traffic. Therefore, the SE that controls the overload traffic can increase the system performance by distributing the overload traffic to other SEs.

The algorithm of the present invention is then terminated.

5 shows an SE device in an All IP based communication system according to an embodiment of the present invention.

Referring to FIG. 5, the SE includes a first interface unit 500-1, a second interface unit 500-2, a switching controller 502, a traffic manager 504, a BS selector 506, and traffic. The switch confirmation unit 508 and the SE selector 510 are configured.

The first interface unit 500-1 receives the traffic from the BSs, converts the data into a format defined in the All IP network, and transmits the converted traffic to the switching controller 502.

When the second interface unit 500-2 transmits and receives traffic to the upper network entity of the SE, the second interface unit 500-2 converts and transmits the traffic according to the upper network entity format. In the present invention, the total traffic information currently controlled is received from the switching controller 502 and transmitted to the higher network entity, and the SE information processing the minimum traffic is received from the higher network entity.

The switching controller 502 performs a switching control so that traffic of the BSs received through the first interface unit 500-1 is transmitted to a destination. In addition to the present invention, when traffic outside the allowable range is received from the BSs, the BS generating the overload traffic using the SE information controlling the minimum traffic from the traffic switching confirmation unit 508 controls the minimum traffic. Switch to SE to control so that it does not exceed tolerance. SE information for controlling the minimum traffic may be received from the network entity. Here, the switching controller 502 transmits traffic information from the BSs to the traffic manager 504.

)를 비교하여 비교 결과를 상기 BS 선택부(506)와 상기 SE 선택부(510)로 제공한다(수학식 1 참조).The traffic manager 504 receives the traffic information of each BS from the switching controller 502 and calculates a total traffic amount, thereby calculating the total traffic amount and a predetermined threshold (

) Is provided to the BS selector 506 and the SE selector 510 (see Equation 1).

The BS selecting unit 506 sorts BSs transmitting traffic through the first interface unit 500-1 according to a comparison result from the BS selecting unit 506 in order of traffic size, and transmits the maximum traffic. A BS is selected and notified to the traffic switching confirmation unit 508.

The SE selector 510 receives traffic information of SEs interworking in an All IP network from the switching controller 502 and selects an SE controlling minimum traffic according to a comparison result from the BS selector 506. . The SE selector 510 provides SE information for controlling the minimum traffic selected by the switching controller 502.

)를 제공받고, 상기 BS 선택부(506)로부터 다른 SE로 분산시킬 트래픽 양(

) 정보를 제공받는다.The traffic switching confirmation unit 508 checks whether the SE controlling the minimum traffic can receive the overloaded traffic, and even after attempting to link the BS having the maximum traffic to the SE controlling the minimum traffic. It checks whether the overload condition continues and notifies the switching controller 502 and the BS selector 506. To this end, the traffic switching confirmation unit 508 may determine the amount of traffic that the SE that accepts the minimum traffic from the SE selection unit 510 can accept the overload traffic.

Amount of traffic to be distributed from the BS selector 506 to other SEs

Get information.

3 to 5 illustrate a traffic control apparatus and method using, for example, an SE having a minimum traffic and a BS having a maximum traffic, the SEs having at least one minimum traffic and a BS having at least one maximum traffic. Can be extended to devices and methods for controlling overload traffic.

6 shows a simulation result graph according to an embodiment of the present invention.

In FIG. 6, the experimental environment is as follows. The number of SEs is 6, the number of BSs in one SE is 14, the BS traffic distribution is uniformly distributed, the capacity of the SE is 1 Gbps, the capacity of the BS is 100 Mbps, the threshold of the transmitting SE Is set to 800 Mbps and the threshold of the received SE is set to 760 Mbps. The x-axis is the SE index and the y-axis is the total traffic of each SE.

When the traffic controlled by the SEs exceeds the predetermined threshold (th _m , th _n ) at any moment, the SE 2 selects the BS that transmits the maximum traffic among the BSs it controls to lower the traffic it controls. Optionally, link the BS sending the maximum traffic to SE 4 which is controlling the minimum traffic. This progresses to the moment when the SE 2 having overloaded traffic drops traffic below its threshold, and the reduced amount of traffic is delivered to the SE 4 which controls the minimum traffic, thereby promoting overall network stability.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, when an overload traffic occurs in the SE controlling the BSs in the All IP communication system, by linking some BSs causing the overload to another SE, interruption of service due to forced traffic reduction Can be prevented and handoff of an existing user terminal can be guaranteed.

Claims (16)

A method for controlling switching entity (SE) traffic in an all IP based communication system, Total traffic that collects and controls traffic information from base stations (

) Calculating the quantity, Total traffic (

) Is the preset threshold (

Greater than), selecting a base station transmitting the maximum traffic to give priority to the base station, And determining the link connection to any SE by the base station, which has been given priority, to perform link connection. The method of claim 1, Total traffic (

) Is calculated by Equation 4 below.

Where m is the index of SE, n is the index of BS under SE control, N is the number of BS under SE control,

Is the amount of traffic the mth SE accepts from the nth BS. The method of claim 1, The arbitrary SE has the lowest total traffic than the other SEs, and the predetermined threshold (

) Is set lower than the SE handling heavy traffic. The method of claim 1, The process of link connection by determining whether the base station, which has been given the priority, is capable of link connection to any SE, Determining whether the arbitrary SE can handle the traffic of the base station which has been given priority; And determining whether an overload traffic condition persists in the SE to which the base station belongs even when the base station assigned the priority is linked to the arbitrary SE. The method of claim 4, wherein The process of determining whether the arbitrary SE can handle the traffic of the base station to which the priority is given Free traffic from any of the SEs (

) Compares the traffic of the prioritized base station to the free traffic of the random SE (

Large) link connection is possible. The method of claim 5, Free traffic from any of the SEs (

) Is calculated by Equation 5 below.

Where

Is the amount of traffic that the SE that is accepting the minimum traffic can accept the overloaded traffic,

Is the threshold of the SE receiving traffic, and

Is the amount of traffic in the SE that is accepting minimal traffic. The method of claim 4, wherein The process of determining whether an overload traffic situation persists in the SE to which the base station belongs even when the base station, which has been given the priority link link to the arbitrary SE, The amount of free traffic that can be controlled by the SE after linking the base station to which the priority is given to the arbitrary SE (

) Is greater than 0, the link connection is possible. The method of claim 7, wherein The amount of free traffic that can be controlled by the SE after linking the base station to which the priority is given to the arbitrary SE (

If it is less than 0, it is determined that the overload traffic situation is continued, and after excluding the base station given the priority, the base station transmitting the maximum traffic is selected and the priority is given again. The method of claim 7, wherein The amount of free traffic of the SE to which the base station belongs after linking the prioritized base station to the arbitrary SE (

) Is calculated by Equation 6 below.

Where

Is the amount of free traffic of the SE to which the base station belongs after linking the base station to which the priority is given to the arbitrary SE,

Is the threshold of the SE that carries the traffic, and

Is the total amount of traffic controlled by the SE to which the base station belongs after linking the prioritized base station to the arbitrary SE. The method of claim 1, When the priority base station is not capable of linking to any SE, after removing the priority base station, the base station transmitting the maximum traffic is selected to give priority again. Characterized in that the method. A switching entity (SE) traffic control apparatus in an all IP based communication system, Total traffic that collects and controls traffic information from base stations (

) A traffic management unit that calculates a quantity, Total traffic (

) Is the preset threshold (

Greater than), BS selection unit for selecting the base station transmitting the maximum traffic to give priority (priority), And a traffic switching confirmation unit by determining whether the base station given the priority is capable of linking to any SE. The method of claim 11, The arbitrary SE has the lowest total traffic than the other SEs, and the predetermined threshold (

) Is set lower than the SE handling heavy traffic. The method of claim 11, The traffic conversion confirmation unit Determine whether the arbitrary SE can handle traffic of the prioritized base station, And determining whether the overload traffic condition persists even when the base station, which has been given the priority, has a link connection to the arbitrary SE. The method of claim 11, The traffic conversion confirmation unit When the priority base station is not capable of linking to any SE, after removing the priority base station, the base station transmitting the maximum traffic is selected to give priority again. Device characterized in that. The method of claim 11, And a switching control unit for switching the base station generating the overload traffic to the arbitrary SE when the priority base station is capable of linking to any SE. The method of claim 11, Total traffic (

) Is the preset threshold (

If greater than), further comprising an SE selection unit for selecting the SE controlling the minimum traffic.

Images