KR20160009372A - Method and apparatus for assigning of ip address - Google Patents

Abstract

The present invention relates to a method and an apparatus for assigning an Internet protocol (IP) address which can prevent a collision of an IP address generated when mutually different packet data network gateways (P-GW) share the same IP pool in accordance with an IP pool policy. The apparatus for assigning the IP address of the present invention maps information about a user terminal and information about an assigned first IP address, and stores the same as IP address information when the first IP address is assigned for the particular user terminal; determines whether pre-stored IP address information including the first IP address and newly assigned IP address information including a second IP address are same or not; and requests a gateway to reassign a new IP address without using the second IP address, when the first and second IP addresses are same with each other.

Description

TECHNICAL FIELD [0001] The present invention relates to an IP address assigning method,

The present invention relates to a mobile communication field, and more particularly, it relates to a mobile communication field, and more particularly, to an IP address pool conflict that occurs when different P-GWs (Packet Data Network Gateways) share the same IP pool according to an IP (Internet Protocol) And more particularly, to a method and apparatus for allocating an IP address.

Recently, due to the rapid development of communication, computer network and semiconductor technology, not only various services using wireless communication networks have been provided, but the demand of users has been increasing day by day, and the global wireless Internet service market has been exploding Trend. Accordingly, a service provided by a mobile communication system using a wireless communication network is being developed not only as a voice service, but also as a multimedia communication service for transmitting various data. Recently, with the increase of smart phones and the demand for data traffic, mobile operators are investing equipment and technology considering the system part and the influence to accommodate the increased data traffic in various ways.

Long Term Evolution (LTE) is a network for realizing requirements of high data rate, low-latency, and packet optimized radio access for an access network , And is designed to accommodate high-speed rich media while ensuring backward compatibility with existing 3GPP / non-3GPP access networks. LTE is an All-IP-based network that excludes existing circuit-switched based communications and enhances quality of service (OoS) management functions to provide real-time services (eg, voice communications, video communications) Thereby improving the efficiency of network resources by providing differentiated QoS for real-time services (e.g., web browsing, Store and Forward data transmission). We also extended the bandwidth for wireless communications by introducing smart antenna technology (MIMO: multiple input multiple output).

In the Evolved Packet Core (EPC) network, which is an LTE core network, the eNodeB, the MME, the MME, the Serving Gateway, and the S-GW < GW (Packet Data Network-Gateway) to perform call processing for voice and data processing. In the EPC network, a control message such as call setup and release is recognized as an IP packet and transmitted to the P-GW or received from the P-GW and transmitted to the user equipment (UE). When the user terminal accesses the LTE network at the initial connection, the LTE network can request a PDN connection for using the IP network. At this time, the P-GW assigns an IP address to be used by the user to the PDN and transmits the IP address to the user terminal, and the user terminal uses the voice and data processing service using the transmitted IP address. The P-GW assigns an IP address to two methods, a static IP address allocation method and a dynamic IP address allocation method. The fixed IP address allocation method allocates a specific IP address only for a specific subscriber, and the dynamic IP address allocation method is a method in which a plurality of user terminals share an assigned IP address by allocating an IP address for each IP address at a specific server to be. Therefore, in the dynamic IP address assignment method, a duplicate IP address can not be assigned at the same time, and a plurality of user terminals occupy a specific IP address in different time zones. In order to use the network more effectively, the IP address allocation method is used to allocate an IP address whenever a request for a user terminal is requested, effectively utilizing a limited IP pool.

In the dynamic IP address assignment method, the P-GW manages the IP pool and dynamically allocates the IP address each time the user terminal accesses the network. Since a plurality of P-GWs share the same IP pool, when an IP address allocated to a specific user terminal is the same as an IP address allocated to another user terminal, or when the same user terminal repeatedly requests a PDN connection, There is a problem in that the network can not be used because the IP addresses are collided with each other. This is called duplicate IP address allocation. When one user terminal requests only one service, the duplicated IP address allocation does not occur. However, when two or more IP addresses are allocated to one user terminal due to a new service request of the same user terminal, Problems can arise. For example, if a user terminal requests an Internet service while receiving a voice call service, a new IP address assignment is required. According to the standardization protocol, theoretically, up to 11 IP addresses can be allocated to each user terminal.

Korean Patent Publication No. 10-2011-0011574 (published on Mar. 2, 2011)

According to the present invention, an IP address allocation that can prevent an IP address conflict, which occurs when different P-GWs (Packet Data Network Gateways) share the same IP pool according to an IP (Internet Protocol) Method and apparatus.

According to another aspect of the present invention, there is provided a method for allocating an IP address by an IP address assigning apparatus, comprising the steps of: a) when a first IP address is assigned to a specific user terminal, B) storing the previously stored IP address information, including the first IP address, and newly allocated IP address information, including the second IP address; and c) requesting the gateway to reallocate the new IP address without using the second IP address if the first and second IP addresses are identical to each other.

The IP address assigning apparatus of the present invention may further include a step of, when a first IP address is assigned to a specific user terminal, mapping information on the user terminal and the allocated first IP address to store the IP address information And a processor for requesting to reallocate a second IP address different from the first IP address, wherein the processor is further configured to compare the IP address information stored in the storage unit with the first IP address, The IP address information of the second IP address is identical to the second IP address, and when the first and second IP addresses are identical to each other, request.

According to the present invention, in the dynamic IP address allocation method, it is possible to maintain the continuity of the existing service by preventing the duplicated allocation of the IP address to provide a better service quality.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing a configuration of a mobile communication network according to an embodiment of the present invention; Fig.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]
3 is a diagram illustrating a call processing procedure for packet and voice service support in an EPC network according to an embodiment of the present invention.
FIG. 4 illustrates an example of a configuration of an IP address assignment apparatus according to an embodiment of the present invention. FIG.
FIG. 5 and FIG. 6 are views illustrating a procedure of an IP address allocation method according to an embodiment of the present invention; FIG.
7 is a flowchart illustrating a procedure of an IP address assignment method according to 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.

In one embodiment, the mobile communication network includes a wireless network such as a Global System for Mobile communication (GSM), a 2G wireless communication network such as CDMA, an LTE network, a wireless Internet such as WiFi, a Wireless Broadband Internet (WiBro), and a World Interoperability for Microwave Access (For example, 3G mobile communication network such as WCDMA or CDMA2000, High Speed Downlink Packet Access (HSDPA) or 3.5G mobile communication network such as High Speed Uplink Packet Access (HSUPA), or the like) A 4G mobile communication network currently in service, and any other mobile communication network including a macro base station (macro eNodeB), a micro base station (Pico eNodeB, Home eNodeB), and a user terminal (UE: User Equipment) However, the present invention is not limited thereto. Hereinafter, an E-UTRAN (Evolved Universal Terrestrial Radio Access Network) as a radio access network of LTE will be mainly described.

As shown in FIG. 1, the mobile communication network may include one or more network cells, and may include a Heterogeneous Network (HET) environment in which different kinds of network cells may be mixed in a mobile communication network. The mobile communication network includes miniature base stations (Pico eNodeB, Home-eNodeB, relay, etc.) 11 to 15, 21 to 23, and 23, which manage small-sized network cells (e.g., 'small cells' such as picocells, femtocells, (Macro eNodeBs) 10, 20, and 30 that manage a wide range of cells (e.g., 'macro cells'), user terminals 40, SON (Self Organizing & Optimizing (MSS) 60, an S-GW (Serving Gateway) 80, a P-GW (Packet Data Network) gateway 90 and an HSS (Home Subscriber Server) (100). The number of each component shown in FIG. 1 is illustrative, and the number of each component of the mobile communication network in which the present invention can be implemented is not limited to the number shown in the drawings.

For example, the macro base stations 10, 20 and 30 can be used in an LTE network, a WiFi network, a WiBro network, a WiMax network, a WCDMA network, a CDMA network, a UMTS network, But is not limited to, the characteristics of the macro cell base station that manages the base station.

The micro base stations 11 to 15 and 21 to 23 and 31 to 33 can be used in an LTE network, a WiFi network, a WiBro network, a WiMax network, a WCDMA network, a CDMA network, a UMTS network, but is not limited to, the features of a pico base station, an indoor base station or a femto base station, or a relay that manages a cell having a radius of about m to several tens of meters.

The micro base stations 11 to 15, 21 to 23, and 31 to 33 and the macro base stations 10, 20, and 30 can independently have connectivity with the core network.

The user terminal 40 may be a mobile Internet network such as a GSM network, a 2G wireless communication network such as a CDMA network, a wireless Internet network such as an LTE network and a WiFi network, a WiBro network, and a WiMax network, But are not limited to, the characteristics of the terminal.

The management server (O & M server) 70, which is a network management apparatus of the micro-base station, is responsible for configuration information and management of the micro-base stations 11 to 15, 21 to 23 and 31 to 33 and the macro base stations 10, 20 and 30 . The management server 70 can perform all the functions of the SON server 50, the MME 60, and the HSS 100. [ SON server 50 may include any server that performs macro / micro base station installation and optimization and functions to provide basic parameters or data necessary for each base station. The MME 60 may include any entity used to manage the mobility of the user terminal 40 and the like. In addition, the MME 60 performs a function of a base station controller (BSC) and performs resource allocation, call control, handover control, voice and packet processing, and the like on the base stations (pico eNodeB, home eNodeB, macro eNodeB, Control and so on. The HSS 100 is a kind of database for service / authentication of the subscriber.

In one embodiment, one management server 70 can perform all the functions of the SON server 50, the MME 60, and the HSS 100, and the SON server 50, the MME 60, The base station 100 can manage one or more macro base stations 10, 20 and 30 and one or more micro base stations 11 to 15, 21 to 23 and 31 to 33.

Although it is assumed that a macro cell, a pico cell, and a femtocell are mixed in the mobile communication network, the network cell may be composed of a macro cell, a pico cell, and a macro cell.

When the mobile communication network is assumed to be an LTE network, the LTE network is interworked with an inter-RAT network (WiFi network, WiBro network, WiMax network, WCDMA network, CDMA network, UMTS network, GSM network, etc.). (LTE network, WiFi network, WiMax network, WCDMA network, CDMA network, UMTS network, GSM network, etc.) when one of the inter-RAT networks (e.g., WiBro network) is the mobile communication network. (WiFi network, WiMax network, WCDMA network, CDMA network, UMTS network, GSM network, etc.) are shown apart from one another in the drawing, it is assumed that it is overlaid.

When the micro base stations 11 to 15, 21 to 23 and 31 to 33 and / or the macro base stations 10, 20 and 30 are collectively referred to as a 'base station device', the LTE base station device (eNB, The Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) comprises an IP-based flat structure and processes data traffic between the user terminal 40 and the core network. The signal control between them is performed by the MME 60. The MME 60 takes charge of signal control between the base station device 25-n and the S-GW 80 and determines where to route the incoming data from the user terminal 40. [ The S-GW 80 functions as an anchor for the movement of the user terminal between the 3GPP network and the E-UTRAN between the base station device 25-n and the base station device 25-n, To the IP network. The MME 60 / S-GW 80 as a core network equipment manages a plurality of base station devices 25-n, and each base station device 25-n is composed of several cells. The S1 interface is used between the base station apparatus 25-n and the MME 60 / S-GW 80 and the X2 interface is used for the handover and SON functions between the base station apparatuses 25-n.

The setup of the network interface is accomplished by setting up the S1 interface connecting with the MME 60 at the center of the system and the X2 interface, which is a network line for direct communication with the base station device 25-n of other cells present on the current system. The S1 interface exchanges operation and management (OAM) information to support the movement of the user terminal 40 by exchanging signals with the MME 60. [ In addition, the X2 interface exchanges signals for fast handover, load indicator information, and information for self-optimization between the base station apparatuses 25-n.

2 is a diagram illustrating an exemplary configuration of an EPC network according to an embodiment of the present invention.

The E-UTRAN 25 is an LTE radio access network composed of eNBs 25-1, ..., 25-n, ..., and is based on IP and is connected between the UE 40 and a wireless communication core network And transmits data and control information. In addition, when a terminal using the LTE system moves to an existing 2G / 3G mobile communication network using a voice service, a paging request for a circuit switch (Fallback) to receive voice service, an SMS message to the UE 40 ) And a direct connection to a target cell capable of a CS service.

2, "LTE-Uu" represents an air interface between the E-UTRAN 25 and the UE 40, "S1- MME" represents an interface between the E-UTRAN 25 and the MME 60, "S1-U" represents the interface between the E-UTRAN 25 and the S-GW 80, "S11" represents the interface between the MME 60 and the S-GW 80, "S5 / Indicates an interface between the S-GW 80 and the P-GW 90, and "SGi" may indicate an interface between the P-GW 90 and the IP network. And "S6a" may represent the interface between the MME 60 and the HSS 100.

The UE 40 and the eNBs 25-1 to 25-n of the E-UTRAN 25 communicate via the RRC (Radio Resource Control) protocol and the eNB 25- A broadcasting message to a cell area to be controlled by the RRC message is defined as an RRC message. The RRC message may include control messages from the Non-Access Stratum (NAS) protocol, which control messages are transparently transferred to the UE 40 or the core network without being read in the E-UTRAN 25 .

The eNB 25-n is an end point for the radio signal of the E-UTRAN 25 and the control signal is interlocked with the MME 60 via the S1-MME interface and the data traffic is transmitted to the S- (80). The S-GW 80 performs a buffering function for the anchor and downlink traffic for mobility in the E-UTRAN 25. [ The P-GW 90 is an external IP network connection point, and performs IP allocation and billing for a mobile subscriber and traffic control functions for user data.

The IP network provides an IMS (IP Multimedia Subsystem) service for the UE 40 in the EPC network, and includes Policy & Charging Rule Function (PCRF), IMS nodes (for example, Proxy Call Session Control Function (P-CSCF) (Interrogating Call Session Control Function (CSCF), Serving Call Session Control Function (S-CSCF), Application Function (AF)), and the like.

UE 40 sends and receives a call control message for multimedia services using IMS nodes and the Gm interface through an EPC bearer (provided by E-UTRAN / S-GW / P-GW).

The E-UTRAN 25 provides a radio communication function to the UE 40 and performs a function of managing radio resources for the radio communication function.

The MME 60 may receive authentication information for authenticating the UE 40 from the HSS 100 and perform authentication of the UE 40. [ In addition, the MME 60 manages the mobility of the UE 40 and the base station apparatus 25-n at an upper level of the base station apparatus 25-n and can perform call control functions such as bearer setup / release. In addition, the MME 60 can be directly connected to the IP network through the S-GW 80 and the P-GW 90. The call processing control signal of the base station apparatus 25-n is transmitted to the S-GW 80 via the MME 60 and is transmitted to the P-GW 90 ).

The S-GW 80 acts as a gateway between the 3GPP network and the E-UTRAN 25 and performs handover between the base station apparatus and the base station apparatus (inter-eNodeB) and between the 3GPP network and the 3GPP network (inter-3GPP) 40 to provide a mobility anchor function. The S-GW 80 can transmit to the P-GW 90 a job required for call processing according to the control signal of the base station device 25-n.

The P-GW 90 may allocate an IP address to the UE 40 and apply different QoS policies to the UE 40. [ In addition, the P-GW 90 acts as a gateway to a PDN (Packet Data Network), allowing the UE 40 to access a data network such as the Internet or the Internet to receive services.

Although the S-GW 80 and the P-GW 90 are illustrated as being separated and communicating at the S5 / S8 interface as an embodiment, the S-GW 80 and the P- single gateway).

The HSS 100 may manage authentication information for authenticating the UE 40, location information of the UE 40, and the profile of the UE 40. [ The profile of the UE 40 may include QoS rating information (e.g., priority, maximum available bandwidth, etc.) for each service item to which each UE 40 subscribes. In one embodiment, the authentication information for authenticating the UE 40 and the profile of the UE 40 may be transferred from the HSS 100 to the MME 60 when the UE 40 connects to the network.

The PCRF (not shown) manages policies and rules for charging and allows the P-GW 90 and the S-GW 80 to provide appropriate QoS for the UE 40 and use Allows you to perform the billing function for the bearer.

The IMS node (not shown) is made up of nodes such as P-CSCF, I-CSCF, S-CSCF, and AF in detail and the UE 40 provides multimedia services such as VoIP give.

3 is a diagram illustrating call processing procedures for packet and voice service support in an EPC network according to an embodiment of the present invention.

3, when the UE 40 requests the MME 60 for call processing via the E-UTRAN, the MME 60 receives the subscriber information for the UE 40 from the HSS 100 do. GW 80 or P-GW 90, and transmits the bearer for packet transmission to the UE 40. The bearer for the transmission of the packet is called the S-GW 80 and the P-GW 90, respectively.

Specifically, in order to receive the packet service and the voice service, the UE 40 transmits a call processing request message to the radio section in step S310.

The eNB 25-n of the E-UTRAN forwards the call processing request message received from the UE 40 to the MME 60 (S320), and the MME 60 processes the received call processing request message The HSS 100 requests information for preparation of call setup with the UE 40 and receives information for preparation of call setup from the HSS 100 in step S330. The MME 60 selects one of the plurality of S-GWs 80 / P-GWs 90 using the information received from the HSS 100 and requests a bearer setup. When the bearer setup is completed (S340), a packet service and a voice service for the UE 40 are possible. At this time, upon completion of the bearer setup with the S-GW 80 / P-GW 90, the MME 60 transmits a completion message (attach complete) for the attach request of the UE 40 to the user It can be informed that the resource allocation for the network has been approved and assigned in the network. In addition, the MME 60 may transmit location information of the UE 40 to the HSS 100 and perform location registration of the UE 40 (S350).

4 is a diagram illustrating an exemplary configuration of an IP address assignment apparatus according to an exemplary embodiment of the present invention.

4, the IP address assignment apparatus 400 may include a storage unit 410, a processor 420, and a transceiver unit 430. In one embodiment, the IP address assignment apparatus 400 may be included in the MME 60 or the HSS 100, and may be separately provided from the MME 60 or the HSS 100.

The storage unit 410 maps the information about the UE 40 and the assigned IP address to store the IP address information as the IP address information for the specific UE 40, If the IP address assignment is canceled, the stored IP address information can be deleted. In one embodiment, the storage unit 410 may include a ROM (Read Only Memory), a RAM (Random Access Memory), a CD (Compact Dics) -ROM, a magnetic tape, a floppy disk, The present invention is not limited to the above configuration.

The processor 420 receives the IP address information (first IP address information) stored in the storage unit 410 and newly allocated IP address information (second IP address information) when a new IP address is assigned to the specific UE 40, If the first IP address included in the first IP address information and the second IP address included in the second IP address information are the same, the P-GW 90 assigns the second IP address to the P- (Not shown) except for the P-GW 90 to which the MME 60 has assigned the second IP address by forming an IP address reallocation request message for requesting the P-GW (not shown) GW (not shown) may reallocate the IP address, and may control to store the second IP address information in the storage unit 410 when the first IP address and the second IP address are not the same . In addition, the processor 420 may control the specific UE 40 to delete the IP address information stored in the storage unit 410 when the IP address assignment is canceled. In one embodiment, the IP address relocation request message includes the IP address information of the P-GW 90 to which the second IP address is assigned, and the P-GW 90 excluding the P- Not shown) may reallocate the IP address.

The transceiver 430 receives the information about the UE 40 and the assigned IP address each time an IP address is assigned to the specific UE 40. The processor 420 transmits an IP address reassignment request message And transmits an IP address reassignment request message so that the P-GW (not shown) excluding the P-GW 90 to which the MME 60 has allocated the second IP address reassigns the IP address.

The storage unit 410, the processor 420 and the transceiver unit 430 included in the IP address assignment apparatus 400 may be interconnected via the system bus B. [

5 is a diagram illustrating an IP address assignment method according to an exemplary embodiment of the present invention.

FIG. 5 shows a procedure of an IP address reassignment method when a specific UE 40 is assigned an IP address redundantly. An IP address (for example, 1.1.1.1) is assigned to the corresponding UE 40 and the corresponding UE 40 is assigned a specific IP address (for example, 1.1.1.1) when the specific UE 40 attempts to attach and the Attach procedure is completed (S501) The bearer setting is completed between the P-GW 90-2. The IP address information allocated to the UE 40 may be stored in the storage unit 410 of the IP address assignment apparatus 400 included in the MME 60. [ Then, if the UE 40 desires to receive a specific app service (e.g., a kakao talk service), it transmits an additional PDN request message to the eNB 25-n of the E-UTRAN (S502) 25-n may transmit the additional PDN request message received from the UE 40 to the MME 60 (S503). The MME 60 requests the P-GW 90-2 connected to the UE 40 to process the received additional PDN request message and transmits the IP address (for example, 1.1. 1.1), and can generate a bearer (S504). In this case, the MME 60 requests the additional PDN and the IP address allocated by the corresponding UE 40 to determine whether or not the allocated IP addresses are the same, and requests the IP address and the additional PDN allocated in the connection attempt If the assigned IP address is the same, the IP address information of the P-GW 90-2 to which the IP address has been allocated is stored (S505), and an additional PDN failure message can be transmitted to the UE 40 which transmitted the additional PDN request message (S506). The UE 40 which has received the additional PDN failure message can transmit an additional PDN request message to the HSS 100 in step S507 and the HSS 100 transmits the information to the MME 60 so that the MME 60 transmits the same IP The P-GW 90-1 requests reallocation of the IP address to the P-GW 90-1 except for the P-GW 90-2 to which the address is assigned, and the P-GW 90-1 transmits a new IP address (for example, 2.1.1.1 And the MME 60 can generate bearer with the P-GW 90-1 using the re-allocated IP address (S508). When bearer generation is completed between the MME 60 and the P-GW 90-1, the MME 60 transmits the location information of the UE 40 to the HSS 100 and performs location registration of the UE 40 , IP address information is transmitted to perform IP address registration (S509), and a call processing request success message may be transmitted to the corresponding UE 40 (S510).

6 is a diagram illustrating an IP address assignment method according to an exemplary embodiment of the present invention.

6 shows a procedure of an IP address allocation method when the first UE 40-1 and the second UE 40-2 are assigned with IP addresses redundantly, respectively. When assigning an IP address for receiving a mobile communication service, the first UE 40-1 and the second UE 40-2 check whether the IP address assigned by the HSS 100 is duplicated or not, 40-1, and 40-2 to be assigned different IP addresses. In one embodiment, when the first UE 40-1 attempts to attach and the Attach procedure is completed (S601), the first UE 40-1 transmits an IP address (e.g., 1.1.1.1 ) Is allocated to complete the bearer setup between the first UE 40-1 and the specific P-GW 90-2. Then, the eNB 25-n of the E-UTRAN transmits a call processing request message to the second UE 40-2 in order to receive the packet service and the voice service in step S602, The MME 60 forwards the call processing request message received from the second UE 40 to the HSS 100 to process the received call processing request message to the MME 60 in step S603, 2), and receives information for preparation of call setup with the second UE 40-2 from the HSS 100 (S604). The MME 60 can request a bearer setup by selecting one of the P-GWs 90-2 from among the various P-GWs 90 using the information received from the HSS 100. [ When the bearer setup is completed (S605), the packet service and the voice service for the second UE 40-2 are possible. When bearer generation is completed between the MME 60 and the P-GW 90-2, the MME 60 transmits the location information of the second UE 40-2 to the HSS 100, 2), and performs IP address registration by transmitting IP address information (S606). In this case, the HSS 100 determines whether or not the IP address allocated to the first UE 40-1 is identical to the IP address allocated to the second UE 40-2 when the second UE 40-2 attempts to connect to the HSS 100, IP address of the P-GW 90-2 to which the address has been allocated in step S607, and transmits a call processing request failure message to the second UE 40-2 that has transmitted the call processing request message (S608 ). The second UE 40-2 having received the call processing request failure message can transmit a call processing request message to the HSS 100 in step S609 and the HSS 100 transmits the information to the MME 60, The P-GW 90-1 requests the IP address reallocation to the P-GW 90-1 except for the P-GW 90-2 to which the P-GW 60 assigns the same IP address, The MME 60 may generate a bearer with the P-GW 90-1 using the reassigned IP address (S610). When bearer generation is completed between the MME 60 and the P-GW 90-1, the MME 60 transmits the location information of the second UE 40-2 to the HSS 100, 2, performs IP address registration, performs IP address registration (S611), and transmits a call processing request success message to the second UE 40-2 (S612).

7 is a flowchart illustrating a procedure of an IP address assignment method according to an embodiment of the present invention.

When the IP address is assigned to the specific UE 40, the IP address assignment apparatus 400 may map the information about the UE 40 and the IP address and store the information as IP address information (S701). The IP address assigning apparatus 400 can determine whether the newly allocated IP address information is the same as the already stored IP address information or not (S702), and determines whether the newly allocated IP address and the newly allocated second If the IP address is the same, the second IP address may be reallocated without using the second IP address (S703). At this time, the P-GW 90 that has assigned the second IP address redundantly can prevent duplicate IP address assignment by excluding it when the second IP address is reallocated. If the first IP address and the second IP address are not the same, the second IP address information may be mapped to the corresponding UE 40 and stored, and the procedure may be terminated. If the IP address is reassigned to the specific UE 40 in step S703, it is determined whether the reassigned IP address is duplicated (S704). If the reassigned IP address is duplicated with the first IP address It may request the reassignment of the IP address again (S703). If it is not overlapped with the first IP address, the reassigned IP address may be mapped to the corresponding UE 40, and the procedure may be terminated. In one embodiment, when an IP address is redundantly assigned to a specific UE 40, the IP address reallocation may be performed in the MME 60, and the IP addresses of the different UEs 40-1 and 40-2 may be duplicated If assigned, the IP address reassignment may be performed in the HSS 100.

Although the method has been described through particular embodiments, the method may also be implemented 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 certain 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 will be apparent to those skilled in the art to which the invention pertains. something to do. It is also contemplated that such variations and modifications are within the scope of the claims appended hereto.

11 ~ 15, 21 ~ 23, 31 ~ 33: micro base stations 10, 20, 30: macro base station
40: User terminal 50: SON server
60: MME 80: S-GW
90: P-GW 100: HSS
400: IP address assignment device 410:
420: Processor 430: Transmitting /
B: System bus

Claims (6)

An IP address assignment method by an IP address assignment apparatus,
a) mapping information on the user terminal and information on the allocated first IP address to the IP address information when the first IP address is assigned to a specific user terminal;
b) determining whether the stored IP address information includes the first IP address and the newly allocated IP address information and the second IP address are the same;
c) requesting a gateway to reallocate a new IP address without using the second IP address if the first and second IP addresses are identical to each other
Gt; IP &lt; / RTI &gt; The method according to claim 1,
The step c)
Requesting to re-allocate the second IP address to another P-GW other than the P-GW (Packet Data Network-Gateway) to which the second IP address is allocated. The method according to claim 1,
The step c)
Assigning the second IP address to the same user terminal by means of an MME (Mobility Management Entity) if the first IP address is identical to the second IP address, And performing a reallocation of the second IP address by an HSS (Home Subscriber Server) when the second IP address is identical to the second IP address. As an IP address assignment device,
A storage unit for storing information on the user terminal and information on the allocated first IP address as IP address information when a first IP address is assigned to a specific user terminal;
Requesting a reallocation of a second IP address different from the first IP address,
Wherein the processor determines whether the IP address information stored in the storage unit includes the first IP address and the newly allocated IP address information and the second IP address are the same, And requests the gateway to reallocate a new IP address without using the second IP address if the addresses are identical to each other. 5. The method of claim 4,
Wherein the message requested by the gateway includes IP address information of the P-GW to which the second IP address is allocated. 5. The method of claim 4,
The processor comprising:
Assigning the second IP address to the same user terminal by means of an MME (Mobility Management Entity) if the first IP address is identical to the second IP address, Allocates the second IP address to the home subscriber server (HSS) when the second IP address is identical to the second IP address.

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