KR20130032148A - Auto-configuration method and mobile telecommunication system for the same - Google Patents

Abstract

PURPOSE: An automatic address setting method and a mobile communication system for the method are provided to solve the troublesome of physical switching or setting passively. CONSTITUTION: When a BSC(Base Station Controller)(106a) transmits an IGMP-join packet having an IP-MC address(201,202), a BTS(Base Transmission Subsystem)(108) operates and transmits a registration request message to an IP-based Abis backhaul network by setting a destination address of an IP header as an IP-MC value (203). If a plurality of BSC in service exists, the same registration request message is able to reach to a plurality of BSC at the same time(204,205). When responding to a registration accept message of the registration request message, the BSC is able to intentionally control the response time by considering the load of the BSC. [Reference numerals] (AA) Proceeding registration procedures; (BB) Disregard;

Description

AUTO-CONFIGURATION METHOD AND MOBILE TELECOMMUNICATION SYSTEM FOR THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and more particularly, to an automatic address setting method for automatically switching to another base station control device available when a base station control device (for example, BSC, MME, etc.) occurs, and a mobile communication system therefor. will be. In addition, it is to allow a new registration to the base station control device.

Recently, with the rapid development of the mobile communication field, a next generation wireless multimedia service such as moving picture and multimedia transmission using a mobile phone has been provided, and a packet data service network for packet data processing has been proposed. An EV-DO mobile communication system, one of such packet data service networks, is a representative mobile communication system having a channel structure for high-speed data transmission.

In the 1x EV-DO system, each base transceiver system (BTS) is interworked with a base station controller (BSC), which is an upper node, which is a packet control function (PCF) and a packet. It is a structure that is interworked with a server of the internet network through a packet data serving node (PDSN). Here, the "Abis interface" BTS and the BSC section, for example, is configured as a separate path in the port unit, such as E1 / T1, if the BSC fails and can no longer receive service, From the standpoint of the BTS, there is a problem in that the normal service transfer cannot be performed without the physical work such as the establishment and transfer of the relay line to a separate BSC through the direct intervention of the operator.

As another example, the Abis section can be configured as an IP backhaul using the Internet instead of E1 / T1. For BTS, the BSC, which is its parent node, is defined in advance with an IP address. The need for physical work by the operator can be somewhat solved, but the problem of resetting the IP address of the new BSC still occurs. Since the performance / capacity of the BSC is greatly increased, and the number of BTSs that can be accommodated increases, there is a problem that all BTSs accommodated therein must be manually set.

Korean Patent Publication No. 2009-51559 (2009.05.22 published)

It is an object of the present invention to provide an automatic address setting method and a mobile communication system for automatically switching to another base station control device available when a base station control device (eg, BSC, MME, etc.) occurs.

Another object of the present invention is to provide an automatic address setting method for allowing a new registration to a base station control apparatus and a mobile communication system therefor.

According to an aspect of the present invention, an automatic address setting method and a mobile communication system for automatically switching to another base station control device available, in particular, when a base station control device (eg, BSC, MME, etc.) occurs. According to the present invention, at least one base station control device receives a registration request message from the base station, and transmits a registration acceptance message in response to the registration request message. The base station then determines the available base station control apparatus based on the delay time of the registration acceptance message. On the other hand, when a failure of the currently linked base station control device (serving base station control device) occurs, it automatically switches over to the available base station control device. Here, the at least one base station controller determines whether to transmit the registration acceptance message in consideration of the load, or arbitrarily adjusts the delay time in consideration of the load and transmits the registration acceptance message. This registration request message and registration acceptance message include an IP multicast address.

According to the present invention, the load of the base station controller (e.g., BSC, MME, etc.) is distributed, and in particular, when a failure of one base station controller occurs, the automatic transfer to another base station controller eliminates the trouble of physical switching or manual setting. There is an advantage to this.

1 is a diagram schematically illustrating a configuration of an exemplary EV-DO mobile communication system in which the present invention may be implemented.
2 is a flow diagram illustrating a procedure for determining available BSCs in accordance with an embodiment of the present invention.
3 is a diagram illustrating a registration acceptance message response process according to an embodiment of the present invention.
4 is a flow chart illustrating a rebalancing procedure upon failure recovery in accordance with an embodiment of the present invention.
5 is a diagram schematically illustrating the configuration of an exemplary LTE network in which the present invention may be practiced.
6 is a flowchart illustrating a procedure for determining available MME in accordance with an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions will not be described in detail if they obscure the subject matter of the present invention.

1 schematically shows a configuration of an exemplary EV-DO mobile communication system in which the present invention can be practiced.

1, an EV-DO mobile communication system includes terminals (ATs) 110a to 110h, base transceiver subsystems (BTS) 108a to 108h, a base station controller (BSC) A packet data serving node (PDSN) 11, and a packet data serving node (PDSN) 106a to 106d and a packet control function (PCF) 104a and 104b, An authentication / authorization / accounting (AAA) 12, a home agent (HA) 13, an ACS (Auto Configuration Server) 14, an address allocation server (DHCP server) 15 And a packet core network. Above the packet core network, a DSC (Data Service Controller) server (not shown) is provided.

The ATs 110a to 110h receive calls from or receive BTSs 108a to 108h from the BTSs 108a to 108h through BTSs 108a to 108h that manage their respective regions and through reverse and forward wireless links, The call is sent to. When the ATs 110a to 110h attempt to start communication in the cell to which they belong, the AT 110a first requests the PCFs 104a and 104b, which are unique identifiers, and performs session negotiation with the PCFs 104a and 104b. Although it is shown in FIG. 1 that there is one AT in a cell that is handled by one BTS for convenience, it is well known to those skilled in the art that a plurality of ATs can exist in one cell.

The base transceiver stations (BTS) 108a through 108h process calls originated and terminated by the BTS 108, including a BTS Signaling Processor (BSP), a channel card (CHC) ). The BTSs 108a-108h are each connected to a corresponding BSC 106a-106d.

The base station controllers (BSC) 106a to 106d perform resource allocation, call control, handoff control, voice, and packet processing for the BTSs 108a to 108h connected thereto. The BSCs 106a through 106d receive and process calls and OAM processing from their own Call / Common Control Processor (CCP) and a plurality of BTSs 108a through 108h managed by the BSCs 106a through 106d And a Selection Processor (SLP) for performing radio link protocol (RLP) processing. In FIG. 1, 64 BTSs are connected to one BSC. However, according to another embodiment of the present invention, more or less BTSs can be connected.

In particular, the interval between the base stations (BTS) 108a to 108h and the base station controller (BSC) 106a to 106d, which are the Abis interfaces, may be constituted by separate paths on a port basis such as E1 / T1 or an IP backhaul .

BSCs 106a-106d are also connected to PCFs 1 and 2 104a and 104b, respectively, which provide an interface between BSCs 106a-106d and PDSN 11, and PCFs 1 and 2 104a and 104b.

The PCFs 1 and 2 (104a and 104b) are responsible for traffic forwarding and session management and mobility management for the mobile terminal. The PCFs 1 and 2 104a and 104b are connected to the PDSN 11 and receive packet data from the PDSN 11 and respectively manage the subnets 112a and 112b and have their own subnet ID and color code ). Although two PCFs 104a and 104b are shown as being connected to the PDSN 11 for convenience in FIG. 1, according to another embodiment of the present invention, a larger number of PCFs may be connected to the PDSN.

The PCFs 1 and 2 104a and 104b include a Packet Control Processor (PCP) that processes packet data calls and performs session and mobility management and OAM processing for the AT, and a Packet Interface Processor (PIP: Packet I / F Processor). Specifically, the PCP included in the PCF 1 104a manages session information for the ATs 110a through 110d, and the PCP built in the PCFs 104b manages session information for the ATs 110e through 110h .

The PDSN 11 provides packet data services to the ATs 110a through 110h in cooperation with the PCFs 104a and 104b and the external network. The home agent (HA) 13 is responsible for authentication, authorization and accounting for the subscriber, and the AT (110a-110h) Mobile IP for providing mobility. The ACS (Auto Configuration Server) 14 remotely provision and manages, for example, CPEs (Customer Premises Equipment). The types of CPEs include residential gateway, IPTV set-top box, VoIP adapter, and Femtocell AP (Access Point). In addition, the DHCP server 15 allocates a Mobile IPv4 / IPv6 address.

Specifically, a plurality of PCFs 104a and 104b are connected to the PDSN 11, and each of the PCFs 104a and 104b has a subnet. When the ATs 110a to 110h belonging to one subnet start the wireless data communication under the EV-DO system, the PCFs 104a and 104b controlling the subnet communicate with the ATs 110a to 110h, (Unicast Access Terminal Identifier) and manages session information (a database including terminal information determined through parameter negotiation between the terminal and the RAN) for the ATs 110a to 110h. When ATs 110a through 110h move from one subnet (source subnet) to another subnet (target subnet), the ATs 110a through 110h are moved from the PCF of the target subnet to the target subnet The new UATI is allocated and the PCF of the target subnet can continuously communicate by retrieving the session information through communication with the PCF of the source subnet.

When the ATs 110a to 110h move from the source subnet to the target subnet, the ATs 110a to 110h receive the subnet ID broadcasted from the PCF of the target subnet and recognize that the subnet has been changed. Upon recognizing the change in the subnet, the ATs 110a to 110h terminate the session associated with the PCF of the source subnet, establish a new session with the PCF of the target subnet, and reassign the UATI. As such, upon handoff, ATs 110a through 110h are assigned a new UATI from the target PCF, and the PCF of the target subnet recovers the session from the PCF of the source subnet. Accordingly, the ATs 110a to 110h moved to the target subnet area can communicate with the PSDN through the BTS, BSC, and PCF of the target subnet.

The first embodiment of the present invention distributes the load of the base station controllers (BSC) 106a to 106d and automatically switches to another base station controller when a failure of one base station controller occurs. The second embodiment of the present invention can also be used upon new registration with the base station controller (BSC) 106a to 106d.

Looking at the common parts for the first and second embodiments, in selecting the base station controller (BSC) 106a-106d, where the base station (BTS) 108a-108h is an upper node, the predefined identifier ( It is necessary to be able to set the interworking relationship between BTS and BSC dynamically, not IP address, and in this process, many BSCs 106a to 106d may exist so that each BSC 106a to 106d has its own performance / capacity. Consider additionally whether to accept the BTS. That is, each BSC 106a to 106d determines the load in consideration of its performance / capacity and additionally determines whether to accept the BTS. In the case of determining further acceptance of the BTS, the BSCs 106a to 106d transmit a registration accept message to the BTSs 108a to 108h. Thereafter, each BTS 108a to 108h determines a backup BSC (hereinafter, referred to as an "available BSC") that first transmitted the registration acceptance message based on the response time (delay time) of the registration acceptance message. On the other hand, for the first embodiment, when a failure occurs in the currently accepted (interlocked) BSC (hereinafter referred to as 'serving BSC' for convenience) automatically switches to another available BSC without operator intervention.

As an example for the first and second embodiments, the BSCs 106a to 106d may transmit the registration acceptance message without adjusting the response time (delay time) of the registration acceptance message, wherein the BSC with less load is sent. The registration acknowledgment message arrives early to the BTS 108a through 108h, and the registration acknowledgment message sent by the heavily loaded BSC arrives late into the BTS 108a through 108h, so the BTS 108a through 108h responds with a response time (delay time). The BSC sending this short registration accept message is determined as an available BSC.

As another example, the BSCs 106a to 106d may transmit the registration acceptance message by arbitrarily adjusting the response time (delay time) of the registration acceptance message, for example, if the BTS does not allow further acceptance of the BTS, the response time (delay time). To increase the size of the BTS and to allow the additional acceptance of the BTS, shorten the response time (response time) and transmit the registration acceptance message. The BTSs 108a to 108h then determine the available BSC as the BSC that sent the registration accept message with a short response time (delay time).

Specifically, the BTSs 108a-108h should be able to automatically discover the BSCs 106a-106d to determine available BSCs. For this purpose, IP multicast is used between the BTSs 108a through 108h and the BSCs 106a through 106d. A more detailed description will be given later.

The multiple BSCs 106a through 106d decide whether or not to accommodate the BTSs 108a through 108h according to their performance / capacity. For this purpose, the BSCs 106a through 106d determine that the BTSs 108a through 108h are IP multicast addresses. Receives a registration-request message (hereinafter referred to as a "REG-request message") sent to the BTS (108a-108h) by making the delay time of the response message as a function of the load of the BSC. send. That is, the BSCs 106a to 106d transmit a registration-accept message (hereinafter referred to as a 'REG-accept message') to the BTSs 108a to 108h by increasing the delay time when the load is large, and loading the load. If is small, the delay time is reduced, and the REG-accept message is transmitted to the BTSs 108a to 108h. In addition, even if the BSCs 106a to 106d do not arbitrarily adjust the delay time as described above, the registration accept message transmitted by the BSC having a low load arrives early to the BTSs 108a to 108h as described above. The registration acceptance message sent arrives late at the BTS 108a-108h. This is because a registration request message that reaches a heavily loaded BSC is further queued and processed.

The BTSs 108a through 108h determine the available BSCs with less load as BSCs due to the response time (delay time) of the registration accept message transmitted from each BSC 106a through 106d. In one embodiment, the registration accept message determines the first received BSC as an available BSC.

On the other hand, when the serving BSC fails (the failure is determined when there is no response for a certain time through periodic heartbeat message transmission and the response of the BSC), the BTS 108a to 108h is identical to the initial registration request to the available BSC. By following the procedure, the registration request is sent to the IP multicast address and automatically accepted by the available BSC.

Looking at the IP multicast address allocation process in detail as follows.

IP addressing systems are IPv4 and IPv6. The IPv4 addressing system has a total of 12 characters, divided into four parts (each part represented by three digits from 0 to 255), and the IPv4 address consists of 32 bits. The IPv6 address is composed of 128 bits to solve the problem of address depletion, and supports the mobility of the wireless terminal in the IP layer through the automatic address setting function. In the present invention will be described based on IPv4.

The difference between multicast transmissions and ordinary unicasts lies in the transport packets. In general, an Internet application program over TCP / IP transmits a packet by indicating the IP address of a receiver to which the sender of the data is to be received in the header of the transmission packet. However, for multicast transmission, the packet is transmitted by indicating the group address of the receiver instead of the receiver's address in the header. Since the group address for multicast transmission is a D Class address and is not an address representing a real host unlike A, B, and C Class IP addresses representing Internet hosts around the world, a receiver receiving a multicast packet must It is determined whether the packet is accepted by determining whether the group belongs to the IP address.

In the present invention, the multicast of the IPv4 addressing system has a Class D address according to IANA, and the first eight bits of four 8-bit values are specified in the range of 224 to 239 as shown in Table 1 below. have. One of these values is assigned an appropriate IPv4 address.

For convenience of explanation, the procedure of naming an IPv4 address allocated for this purpose as "IP-MC" and referring to FIG. 2 will be described in detail.

When the BSCs 106a to 106d are started and ready for connection (interlocking) service to the BTSs 108a to 108h, the BSCs 106a to 106d implement the Internet Group Management Protocol (IGMP) to explicitly announce this fact. The IGMP-join procedure (201, 202) is performed with the pre-assigned IP-MC address. This information is transmitted to the IP-based Abis backhaul network through a multicast routing protocol such as Protocol Independent Multicast (PIM) (201, 202), and the multicast packet having an IP-MC address is again used by the BSC (106a to 106d). (203 ~ 205). If the BSCs 106a to 106d no longer accept any more BTSs 108a to 108h for performance / capacity reasons (overload) or for maintenance purposes, the IGMP-leave procedure no longer allows the IP-MC packets. May not be received.

That is, when the BSCs 106a to 106d transmit an IGMP-join packet having an IP-MC address (201 and 202), the BTSs 108a to 108h are activated and the destination address of the IP header to interwork with the BSCs 106a to 106d. The registration request message (REG-request message) is transmitted to the IP-based Abis backhaul network using the destination IP address as the IP-MC value (203). At this time, if there are multiple BSCs in service, the same registration request message may arrive at multiple BSCs (BSC-A 106a, BSC-B 106b) at the same time (204, 205), and BSC (BSC-A, The BSC-B) may adjust the time to deliberately respond to the BSC's own load in responding to the registration acceptance message for the registration request message. In other words, the current load value based on the performance / capacity of the BSC (BSC-A, BSC-B) is converted into% and applied. For each% load, the product of the delay_slot_time (eg, 100 ms) value determines the time that the BSC responds to the registration accept message. The delay_slot_time value is determined in consideration of the characteristics of the IP network (RTD: Round Trip Delay) to be used and can be changed by the operator.

When multiple BSCs are received by IP multicast, the registration acknowledgment message is delayed in proportion to the load of the system. Therefore, the BTS receives the registration acknowledgment message sent by the lowest load BSC among interlockable BSCs. Will receive.

In one embodiment, when the BSC-B is heavier than the BSC-A, the BSC-B will send a registration acceptance message 207 later than the BSC-A. That is, the registration accept message 206 transmitted by the BSC-A arrives at the BTSs 108a through 108h before the registration accept message 207 transmitted by the BSC-B. The BTSs 108a to 108h ignore the registration accept message of the BSC-B and determine that the BSC-A having received the registration accept message first, that is, a relatively less loaded BSC-A as an available BSC, performs the registration procedure. That is, the BTSs 108a to 108h use the source address (source IP address) included in the registration acknowledgment message sent by the BSC-A as the identifier to perform detailed registration procedures with the BSC-A.

Looking at the response process of the registration acceptance message in more detail with reference to Figure 3 as follows.

As shown in Fig. 3, when there are two BSCs (A / B) capable of providing the same level of service to the BTS, the BSC responds to the registration request message according to the degree of its system load. By deliberately delaying the (Acknowledgment Message), the lower load BSC can be in charge of the service for the new BTS, thereby equally sharing the load of the BSC.

As another example, if the BSC-B is in service first and then the BSC-A starts service later, the BSC-B will have more system load, and the BTS that will be newly serviced (interlocked) is the algorithm. By virtue of this, it naturally works with the BSC-A with lower load. This is the case where the BSC A / B does not adjust the response time (delay time) of the registration acceptance message, and a delay occurs in the registration acceptance message according to the load.

The BTS determines the available BSC (ie, BSC-A) based on the response time (delay time) of the registration acceptance message sent by the BSC A / B.

Several factors can be considered in determining the load of the BSC, but first consider the CPU load of the system and the number of BTSs currently accommodated compared to the number of designed base stations.

In this state of determining the available BSC, the BTS checks the failure state of the serving BSC and automatically switches to the available BSC when a failure occurs.

Specifically, the BTS transmits a heartbeat message to the serving BSC, which is currently associated with its parent, and receives an ack for it or vice versa (the serving BSC sends a heartbeat message to the BTS and receives an ack for it). Check the status of the serving BSC periodically. Through this, the failure of the serving BSC, which is a peer node, is detected. In the event of a failure of the serving BSC, the BTS sends the registration request message to the available BSC with the destination address (destination IP address) of the IP header as the IP-MC value and is continuously serviced through automatic switching. The registration process for an available BSC is the same as the initial registration request process.

The possibility of chain failure of soluble BSCs above is slim. For this reason, the BSC estimates the current system load in%, taking into account its performance / capacity. If the system is above a predefined engineering limit (eg 70%), the action is to protect itself. Will proceed. Therefore, in this case, the registration acceptance message for the registration request is not delivered.

In addition, if a failure occurs and the BTS is automatically switched from the serving BSC to the available BSC, and the serving BSC is recovered (401), the available BSC performs re-balancing in consideration of the failed BSC (402). . In general, however, when the BSC is switched, disconnection of existing calls (voice and data) occurs, so it is preferable to perform re-balancing at the minimum time (eg, dawn time with the least number of connected calls). The available BSC (now serving BSC) sends an INIT-REG-request message to the BTS to be re-balancing (402), and the received BTS transmits a registration request message to the BSC (403 to 405). In FIG. 4, steps "403" to "407" are performed in the same manner as steps "203" to "207" in FIG.

In the above, the automatic switching scheme of the BSC in the 1x EV-DO system has been described. However, the present invention is equally applicable to the E-UTRAN (LTE) network, which is an evolution of WCDMA. 5 and 6, the BTS corresponds to an eNB (eNodeB) and a BSC corresponds to a MME (Mobility Management Entity). That is, the eNB can automatically select the MME with the least load among a plurality of available MMEs, and if a failure occurs in the corresponding MME, the eNB can automatically select a new available MME without an operator's intervention.

Specifically, each MME determines the load in consideration of its performance / capacity and additionally determines whether to accept the eNB. In case the additional acceptance of the eNB is determined, each MME sends a registration accept message to the eNB. The eNB then determines the available MME based on the response time (delay time) of the registration acceptance message, and automatically switches to another available MME without operator intervention in the event of a failure in the currently accepted (interlocked) MME. .

In one embodiment, each MME may transmit a registration accept message without adjusting the response time (delay time) of the registration accept message, wherein the registration accept message sent by the MME-1 with less load arrives early to the eNB. Since the registration accept message sent by the heavily loaded MME-2 arrives late to the eNB, the eNB determines the available MME MME-1 which has transmitted the registration accept message with a short response time (delay time).

In another embodiment, each MME may arbitrarily adjust the response time (delay time) of the registration acknowledgment message and transmit the registration acknowledgment message, for example, if the eNB does not allow further acceptance, greatly increase the response time (delay time). In addition, if the eNB allows further acceptance, the response time (delay time) is shortened and the registration acceptance message is transmitted. The eNB then determines the available MME as MME-1 which sent the registration acceptance message with a short response time (delay time).

Although the method has been described through specific embodiments, the method may also be embodied as computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the above embodiments can be easily deduced by programmers of the present invention.

Although the present invention has been described in connection with some embodiments thereof, it should be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention as understood by those skilled in the art. something to do. It is also contemplated that such variations and modifications are within the scope of the claims appended hereto.

11: PDSN 12: AAA
13: HA 14: ACS
15: DHCP server 104: Packet Control Function (PCF)
106: Base Station Controller (BSC) 108: Base Station (BTS)
110: terminal (AT)

Claims (19)

As an address setting method of a mobile communication system,
a) at least one base station control device receiving a registration request message from the base station;
b) the at least one base station control device transmitting a registration accept message in response to the registration request message; And
and c) determining, by the base station, an available base station control apparatus based on the delay time of the registration acceptance message. The method of claim 1,
and d) automatically switching the base station to the available base station control device when a failure of the currently linked base station control device (hereinafter referred to as a 'serving base station control device') occurs. The method of claim 1,
And before the step a) is performed, the at least one base station controller requesting the base station to transmit the registration request message through an IGMP-join procedure. The method of claim 3,
The at least one base station control device, the release of the interworking with the base station via the IGMP-leave procedure to notify that the registration request message transmitted from the base station no longer receives, automatic address setting method. The method of claim 1,
The at least one base station controller determines whether to transmit the registration acceptance message in consideration of the load, automatic address setting method. The method of claim 1,
And the at least one base station controller transmits the registration acceptance message by arbitrarily adjusting the delay time in consideration of a load. The method of claim 1,
And the registration request message and the registration accept message include an IP multicast address. 8. The method according to any one of claims 1 to 7,
The delay time is calculated by calculating the load of the system in%, and determined by the product of delay_slot_time,
The value of the delay_slot_time is determined in consideration of the characteristic (RTD) of the IP network to be used, and is a value that can be changed by an operator. 8. The method according to any one of claims 1 to 7,
And the base station determines, as the available base station control device, the base station control device that first received the registration acceptance message. 10. The method of claim 9,
And the base station periodically checks whether a failure of the serving base station control device occurs. The method of claim 10,
And requesting rebalancing from the available base station controller to the base station upon failure recovery of the serving base station controller. A mobile communication system,
At least one base station control device for transmitting a registration accept message in response to a registration request message received from the base station; And
And a base station for determining an available base station control device based on a delay time of the registration accept message. The method of claim 12,
The base station further comprises a function for automatically switching to the available base station control device when a failure of the currently linked base station control device (hereinafter referred to as a 'serving base station control device') occurs. The method of claim 12,
The at least one base station control apparatus requests the base station to transmit the registration request message through an IGMP-join procedure, and the registration request transmitted from the base station through an IGMP-leave procedure when the interworking with the base station is released. A mobile communication system indicating that the message is no longer received. The method of claim 12,
The at least one base station control apparatus determines whether to transmit the registration acceptance message in consideration of the load. The method of claim 12,
And the at least one base station controller transmits the registration acceptance message by arbitrarily adjusting the delay time in consideration of a load. 17. The method according to any one of claims 12 to 16,
The registration request message and the registration acceptance message include an IP multicast address,
The delay time is calculated by calculating the load of the system in%, and determined by the product of delay_slot_time,
The value of the delay_slot_time is determined in consideration of the characteristic (RTD) of the IP network to be used, and is a value that can be changed by an operator. 17. The method according to any one of claims 12 to 16,
And the base station determines the base station control device that first received the registration acceptance message as the available base station control device, and periodically checks whether a serving base station control device has a failure. 19. The method of claim 18,
And the available base station controller requests rebalancing to the base station upon failure recovery of the serving base station controller.

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