KR20150035616A - Apparatus, Method, and Recording Medium for processing Handover in LTE System - Google Patents

Abstract

The present invention relates to a technology which can process a handover of a relevant call without a disconnection in an LTE system even though states of a terminal and a P-GW do not match when a handover of the terminal is performed from an enhanced high rate packet data system (eHRPD) to an LTE system. According to an embodiment of the present invention, the method for processing a handover in an LTE system which is performed by a P-GW comprises the following steps of: (a) checking whether relevant subscriber information exists when a session creation request (create session request (CSR)) message for a handover is received from an MME, or checking whether existing IP information of a relevant terminal exists when a session creation request (PMIP binding update (PBU)) message for a handover is received from a gateway in another network; (b) re-allocating a terminal IP according to the checking result in step (a); and (c) permitting a relevant session by transmitting a CSR message and a PMIP binding ACK (PBA) message to permit the session to the MME and the gateway in the other network respectively in response to the CSR message and the PBU message when the re-allocation of the terminal IP is completed.

Description

[0001] APPARATUS, METHOD, AND RECORDING MEDIUM FOR HANDOVER IN LTE SYSTEM [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handover processing technique in an LTE (Long Term Evolution) system, and more particularly, to a handover processing technique in an LTE (Long Term Evolution) The present invention relates to an apparatus, a method, and a recording medium for handover in an LTE system, which enables a system to process a corresponding handover call without interruption.

In general, when a mobile station attaches an Attach Request for handover from an eHRPD system to an LTE system, a mobile management entity (MME) receives P-GW (PDN Gateway) information to be accessed from an HSS (Home Subscriber Server) Requests the session with the P-GW, and the P-GW accepts the session request from the MME based on the subscriber information to process the handover.

If the handover fails due to various unspecified reasons, the P-GW will not know the state of the mobile station and the network, Information is deleted, thereby causing a state mismatch between the terminal and the P-GW (that is, a state in which the IP of the terminal exists but the corresponding subscriber information is not deleted in the P-GW).

As described above, the P-GW rejects the handover to the corresponding terminal, that is, when the status discordance between the terminal and the P-GW is disagreed, the session request from the MME is rejected. Thus, unnecessary connection retry of the terminal is repeated, And there is a problem that the terminal and manganese disconnection time become long.

Registration No. 10-0965724 (registered on June 15, 2010)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a method and apparatus for handling a handover from an enhanced High Rate Packet Data (eHRPD) system to an LTE system, And to provide a device, a method, and a recording medium for handover in an LTE system, capable of handling a corresponding handover call without interruption in an LTE system.

In order to accomplish the above object, an apparatus for handover in an LTE system according to an aspect of the present invention includes a subscriber station for receiving a Create Session Request (CSR) message for handover from an MME, Or checking whether the existing IP information of the corresponding terminal is present upon receipt of a PMIP Binding Update (PBU) message for handover from a gateway of another network, ; And a reassignment unit for reassigning the terminal IP according to a result of the verification by the information verification unit. The reassignment unit may further include a CSR (Create Session Request) message or a PBU Further includes a session creation response unit for accepting a session by transmitting a Create Session Response (CSR) message or a PBA (PMIP Binding ACK) message to the MME or the gateway of the other network in response to the message And the gateway of the other network may be, for example, an HRPD Serving Gateway (HSGW) of the eHRPD system. The apparatus for handover in the LTE system may include a P-GW.

For example, the reallocation unit may reallocate an existing IP or reallocate a new IP according to the existence of the corresponding subscriber information.

The reallocation unit may reallocate the same IP as the existing IP when the existing IP exists in an IP pool currently being managed and the other terminal is not used in the existing IP of the corresponding terminal, Or if another terminal is in use or does not exist in the IP pool, the new IP can be reassigned.

According to another aspect of the present invention, there is provided a method for performing handover in an LTE system, the method comprising the steps of: (a) receiving a Create Session Request (CSR) message, or when receiving a PMIP Binding Update (PBU) message for handover from a gateway of another network, Confirming whether or not it exists; And (b) reassigning the terminal IP according to the result of the checking in step (a); and (c) when the terminal IP is reallocated in step (b) Receiving a CSR (Create Session Response) message for accepting a session to the MME in response to a Session Request message; And (d) upon completion of the reallocation of the terminal IP in step (b), transmitting a PBA (PMIP Binding ACK) message for session acceptance in response to the PBU message to the gateway of the other network to accept the session And the gateway of the other network may be, for example, an HRPD Serving Gateway (HSGW) of the eHRPD system.

In the step (b), for example, an existing IP may be reallocated or a new IP may be reallocated according to the presence or absence of the corresponding subscriber information.

In the step (b), if the existing IP exists in the currently managed IP pool and another terminal is not used when the existing IP exists in the terminal, the same IP as the existing IP is reassigned, It may reallocate the new IP if it is not present or exists but is being used by another terminal or is not present in the IP pool.

According to another aspect of the present invention, there is provided a computer-readable recording medium storing a program for causing a computer to perform a method for handover in the LTE system.

As described above, according to various aspects of the present invention, when a mobile station attaches a handover from an eHRPD system to an LTE system, re-connection (re) by state mismatch between the UE and the P- -Attach) message can be reduced, the handover success rate can be improved, and the total connection time can be reduced. Accordingly, it is possible to reduce the disconnecting time between the terminal and the LTE network, thereby improving the quality of the customer experience.

1 is a configuration diagram of an LTE system according to an embodiment of the present invention;
2 is a block diagram of an apparatus for handover in an LTE system according to an embodiment of the present invention.
3 is a flow chart of a method for handover in an LTE system according to an embodiment of the present invention, and
4 is a flowchart for terminal IP reassignment in the P-GW 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 drawings, like reference numerals are used to denote like elements in the drawings, even if they are shown in different drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

FIG. 1 is a block diagram of an LTE system according to an embodiment of the present invention. As shown in FIG. 1, an EUTRAN (Evolved) service is provided for a multi-PDN (Packet Data Network )- based data service in an LTE (Long Term Evolution) An eNode B 20 that relays wireless communication with a UE (user's mobile terminal device) 10 to a Universal Terrestrial Radio Access Network (UE), and an eNode B 20 that relays an Evolved Packet Core (EPC) Entity, a mobility management entity) 30, an S-GW (Serving Gateway) 40, a P-GW (PDN Gateway) 50, an HSS (Home Subscriber Server) 60, A charging policy function, and a charging policy rule processing unit 70), and may also include LTE core network nodes such as an HSGW of the eHRPD system as a gateway of the other network interworking with the P- (HRPD Serving Gateway) 80.

The UE 10 can receive the data call origination from the eNode B 20 of the LTE network and transmit the data call origination to the MME 30 as an exchange means and authenticate the subscriber information through the subscriber information received through the interworking with the HSS 60 The session between the S-GW 40 and the P-GW 50 is generated for the call origination according to the exchange function of the MME 30 performing the paging, the session management, the mobility management, the routing, B 20, so that data transmission / reception with the destination node via the Internet can be performed. At this time, charging according to the charging policy rule of the PCRF 70 can be performed.

The UE 10 is a mobile terminal device (or a terminal) of a user (or subscriber), and may be a mobile terminal device such as a smart phone, a notepad, a tablet PC, Terminal, but such a mobile terminal is merely illustrative and may include various mobile terminals capable of receiving data (packet) services over the wireless Internet.

The P-GW 50 according to the present embodiment is a system in which the UE 10 receives a session creation request for handover from the MME 30 or the HSGW 80 at the time of handover access from the eHRPD system to the LTE system (Or abbreviated as IP) for the corresponding UE 10 depending on whether or not the subscriber information of the corresponding UE 10 is present at the time of receiving the message.

FIG. 2 is a detailed configuration diagram of the P-GW 50 shown in FIG. 1 as a configuration of an apparatus for handover in an LTE system according to an embodiment of the present invention. As shown in FIG. 51, a reallocation performing unit 53, and a session creation responding unit 55. [

Upon receipt of a session creation request message for handover, that is, a CSR (Create Session Request) message from the MME 30, the information verification unit 51 identifies a subscriber corresponding to the subscriber information in the received CSR (Create Session Request) GW 50 and when a session creation request message for handover, that is, a PMIP Binding Update (PBU) message, is received from the HSGW 80, the subscriber of the received PBU message Whether there is existing IP information of the corresponding terminal or existing IP information of the corresponding terminal included in the subscriber information of the received PBU message exists in the P-GW 50. [

The reallocation performing unit 53 reallocates the terminal IP according to the above-described confirmation result of the information checking unit 51. For example, if the corresponding subscriber information corresponding to the subscriber information in the CSR (Create Session Request) message is P -GW 50, the existing IP of the terminal included in the subscriber information is reassigned as it is, and if it does not exist, the new IP can be reassigned.

If the existing IP information of the corresponding terminal exists in the PBU message or the existing IP information of the corresponding terminal included in the PBU message exists in the P-GW 50, the reallocation performing unit 53 may, for example, If the existing IP is not present in the PBU message or the P-GW 50 or exists in the existing P-GW 50, If it is in use or does not exist in the IP pool, you can reassign the new IP.

When the reallocation of the terminal IP is completed, the session creation response unit 55 updates the CSR (Create Session Request) message and the CSR Create Session Response) message and a PBA (PMIP Binding ACK) message to the MME 30 and the HSGW 80, respectively.

FIG. 3 is a flowchart of a method for handover in an LTE system according to an embodiment of the present invention, and is applied to the corresponding apparatus of FIG.

First, upon handover, the MME 30 transmits a CSR (Create Session Request) message including subscriber information including information for handover (HO) (Handover Indicator = true) to the PGW 50 The HSGW 80 transmits a handoff indicator option type 2 to the PGW 50 and the existing IP information of the corresponding terminal in step S301. ) Information (step S303), and transmits a PBU (PMIP Binding Update) message including subscriber information including the subscriber information.

Then, the PGW 50 determines whether the corresponding subscriber information corresponding to the subscriber information included in the CSR (Create Session Request) message is present, whether the existing IP information exists in the PBU (PMIP Binding Update) message, or the PBIP (Step S305). Then, the terminal IP is reallocated in step S307 according to the result of the check in step S305. An example of the terminal IP reassignment process in step S307 will be described in more detail with reference to FIG.

Finally, when the reallocation of the terminal IP is completed in step S307, the PGW 50 transmits a CSR (Create Session Response) message for session acceptance to the MME 30 (30) in response to the CSR (Create Session Request) message received in step S301 (S309). In response to the received PBU message in step S303, the PMB (PMIP Binding ACK) message is transmitted to the HSGW 80 to accept the corresponding session.

4 is a flowchart of a method for terminal IP reassignment performed by the P-GW 50 according to an embodiment of the present invention.

First, upon receipt of a CSR (Create Session Request) message for handover from the MME 30 or a PBU (PMIP Binding Update) message for handover from the HSGW 80 (S401), the corresponding CSR GW 50 itself (step S403), or the subscriber information of the PBU (PMIP Binding Update) message is added to the existing IP (For example, IPv4 HA (Home Address) information) is included in the IPv4 address (S405).

If it is determined in step S403 that the corresponding subscriber information does not exist, or if it is determined in step S405 that the existing IP information of the corresponding terminal does not exist, the new IP is reassigned to the terminal in step S407.

On the other hand, if it is determined in step S403 that the corresponding subscriber information is present, the existing IP of the corresponding subscriber information in the subscriber information is reallocated (S415).

If it is determined in step S405 that the existing IP information of the corresponding terminal is present, the corresponding existing IP exists in the IP pool currently being managed (S411) and another terminal is unused (S413) (S411, S413, S415). If the existing IP does not exist in the corresponding IP pool (S411) or another terminal is in use (S413), the new IP is reallocated (S407 ).

When the new IP is reallocated in step S407, the P-GW 50 transmits an initialization message to the related nodes including the PCRF, the IPMS, the OCS, the OFCS, and the like to perform the initialization procedure. (PCRF, IPMS, OCS, OFCS, etc.) at the time of IP allocation in the state where the corresponding subscriber information does not exist in the P-GW (Context not found) (S409).

As described above, a method for handover in an LTE system according to various embodiments of the present invention can be implemented as a computer-readable recording medium including program instructions for performing various computer-implemented operations. The computer-readable recording medium may include a program command, a local data file, a local data structure, or the like, alone or in combination. The recording medium may be those specially designed and constructed for the embodiments of the present invention or may be those known to those skilled in the computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape, optical recording media such as CD-ROMs and DVDs, magneto-optical media such as floppy disks, and ROMs, And hardware devices specifically configured to store and execute the same program instructions. The recording medium may be a transmission medium such as an optical or metal line, a wave guide, or the like, including a carrier wave for transmitting a signal designating a program command, a local data structure, or the like. Examples of program instructions may include machine language code such as those generated by a compiler, as well as high-level language code that may be executed by a computer using an interpreter or the like.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

10: UE (User Equipment)
20: eNode B
30: Mobile Management Entity (MME)
40: S-GW (Serving Gateway)
50: P-GW (PDN Gateway)
51: Information verification section
53: reallocation performing unit
55: Session creation response unit
60: Home Subscriber Server (HSS)
70: Policy and Charging Rule Function (PCRF)
80: HRPD Serving Gateway (HSGW)

Claims (14)

Upon receipt of a Create Session Request (CSR) message for handover from the MME, it is checked whether or not the corresponding subscriber information exists or a PMIP Binding Update PBU) message, the presence or absence of existing IP information of the corresponding terminal; And
And a reallocation performing unit for reallocating the terminal IP according to the result of the checking by the information checking unit. The method according to claim 1,
Upon completion of the reallocation of the terminal IP by the reallocation performing unit, a CSR (Create Session Response) message for session acceptance is transmitted to the MME in response to the CSR (Create Session Request) message, Further comprising a generation response unit operable to transmit the handover request to the mobile station. 3. The method of claim 2,
Upon completion of the reallocation of the terminal IP by the reallocation performing unit, the session creation answering unit transmits a PBA (PMIP Binding ACK) message for session acceptance in response to the PBU message to the gateway of the other network to accept the session Wherein the handover is performed in the LTE system. The method according to claim 1,
Wherein the reallocation unit reassigns the existing IP or reassigns the new IP according to the presence or absence of the corresponding subscriber information corresponding to the subscriber information in the CSR (Create Session Request) message. . The method according to claim 1,
Wherein the reallocation unit reallocates the same IP as the existing IP when the existing IP exists in an IP pool currently being managed and the other terminal is unused in the PBU message in the presence of the existing IP of the corresponding terminal, And reallocates the new IP if the existing IP does not exist or exists but the other terminal is busy or does not exist in the IP pool. The method according to claim 1,
Wherein the gateway of the other network is an HRPD Serving Gateway (HSGW) of an eHRPD system. 7. The method according to any one of claims 1 to 6,
Wherein the apparatus for handover in the LTE system includes a P-GW. A method of performing in a P-GW,
(a) Upon receipt of a Create Session Request (CSR) message for handover from the MME, it is checked whether the corresponding subscriber information exists or a session creation request for handover (PMIP Confirming whether or not existing IP information of the corresponding terminal is present upon receiving a Binding Update (PBU) message; And
(b) reallocating the terminal IP according to the result of the checking in step (a). 9. The method of claim 8,
(c) Upon completion of the reallocation of the terminal IP in the step (b), a CSR (Create Session Response) message for session acceptance is transmitted to the MME in response to the CSR (Create Session Request) Further comprising the steps of: < RTI ID = 0.0 > a < / RTI > 9. The method of claim 8,
(d) receiving a PBA (PMIP Binding ACK) message for accepting a session in response to the PBU message upon completion of reallocation of the terminal IP in the step (b) to the gateway of the other network, Further comprising the steps of: determining whether the handover is to be handled in the LTE system. 9. The method of claim 8,
Wherein the step (b) comprises reallocating an existing IP or reallocating a new IP according to presence or absence of corresponding subscriber information corresponding to subscriber information of the CSR (Create Session Request) message. . 9. The method of claim 8,
In the step (b), if the existing IP exists in an IP pool currently being managed and the other terminal is unused when the existing IP of the corresponding terminal exists in the PBU message, the same IP as the existing IP is reallocated, And reassigning the new IP if the existing IP does not exist or exists but another terminal is in use or does not exist in the IP pool. 9. The method of claim 8,
Wherein the gateway of the other network is an HRPD Serving Gateway (HSGW) of an eHRPD system. A computer-readable recording medium having recorded thereon a program for causing a computer to execute a method for handover in the LTE system according to any one of claims 8 to 13.

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