KR20160084870A - LTE System, Mobile Management Entity and Signal Control Method thereof - Google Patents

Abstract

Disclosed are a long term evolution (LTE) system, a mobility management entity (MME), and a signal control method thereof. For an LTE system, the LTE system in accordance with one embodiment of the present invention comprises: an MME which requires resetting of a bearer when a message set as an active flag, which is used in an idle state through an evolved node B (eNB) in an activating state of data service for a subscriber terminal, is received; and a gateway which, when the bearer resetting is required from the MME, performs the request of the bearer resetting.

Description

[0001] The present invention relates to an LTE system, a mobility management apparatus and a signal control method thereof,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LTE (Long Term Evolution) system, a mobility management apparatus, and a signal control method thereof. More particularly, when a temporary wireless link disconnection occurs while using a terminal data service, A mobility management apparatus and a signal control method capable of preventing a data service provided to a terminal from being disconnected even if a TAU set to an active flag (0) used in a state

3GPP Release 8 describes an EPC (Evolved Packet Core) as a network architecture as one of mobile communication systems. The EPC is a set of network nodes for 3GPP LTE (3 ^rd Generation Partnership Project Long Term Evolution) system, which evolves the core network of the existing 3GPP system architecture, And E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network), and has an efficient network structure that simplifies the network node in order to increase the efficiency of the packet network. Evolved Packet System (LTE) mobile communication system, which is currently being implemented and serviced in Korea.

Such an EPC network can be divided into a logical entity such as a Packet Data Network Gateway (PGW), a Serving Gateway (SGW), and a Mobility Management Entity (MME).

PGW acts as a global mobility anchor for mobility between 3GPP access technology and non-3GPP access technology (CDMA2000, WiMAX, WIFI, etc.) and gateway to external networks. The PGW allocates an IP (Internet Protocol) of a mobile communication terminal, performs session control for interworking with an external Internet network and a non-3GPP network, and has tunneling and IP routing functions for packet services , SGW, and routing information with the external network.

SGW is a mobility anchor for mobility between 3GPP access networks (E-UTRAN, UTRAN, GERAN, etc.). The SGW performs session control processing for payload traffic according to a set session, and performs interworking with the eNodeB and the S1-U interface. The SGW performs a handoff operation in the LTE mobile communication system and 3GPP And is a user plane entity.

The MME is a control plane entity responsible for mobility management and session management of a terminal apparatus moving between eNodeBs, and may be referred to as an exchange server.

Generally, a recovery procedure between a UE and an eNodeB is performed at the time of radio link failure (RLF) while the UE is using data. In this case, if the recovery between the UE and the eNodeB fails, the EPC network must be clearly informed that the wireless link to the EPC network is disconnected during the data service because it is not aware of this situation. To this end, the UE transmits a Tracking Area Update (TAU) or a SR (Service Request) set in the Active Flag (1) in the NAS (Network Access Server) protocol, and the eNodeB transmits the received message And delivers it to the MME through the initial UE. In this case, the MME recognizes the situation and performs a bearer reset in terms of radio (RAB: Radio Access Bearer) and EPC so that the service is not interrupted.

However, when a temporary radio link disconnection occurs during the use of the terminal data service, the MME can receive the TAU set from the eNodeB in the active flag (0) used in the idle state. In this case, the MME There is a problem that the data service provided to the terminal is disconnected due to the idle processing even though the terminal data service is being used.

Published Patent Publication No. 10-2009-0043465 (published on May 05, 2009)

Disclosure of Invention Technical Problem [8] The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a mobile communication system, in which, when a temporary radio link disconnection occurs while using a terminal data service, the MME sets an active flag (0) used from an eNodeB in an idle state And an object of the present invention is to provide an LTE system, a mobility management apparatus, and a signal control method thereof, which can prevent a data service provided to a terminal from being disconnected even if a TAU is received.

According to an aspect of the present invention, there is provided an LTE system in an LTE (Long Term Evolution) system. In an LTE system, a data service is activated for an SS through an evolved Node B (eNB) A mobility management entity (MME) for requesting a bearer reset when receiving a message set to an active flag used in an idle state; And a gateway for performing a bearer re-establishment if a bearer re-establishment is requested by the mobility management apparatus.

Here, when receiving a message set to an active flag used in an idle state via the inode ratio, the mobility management apparatus requests an initial context setting to the subscriber station, and transmits an initial context setting response message to the inode busy do.

According to another aspect of the present invention, there is provided a mobility management apparatus comprising: a TAU receiving unit for receiving a TAU (Tracking Area Update) request message in which an active flag is set via an inode ratio; And a bearer reconfiguration unit for requesting a gateway to re-establish a bearer when a message set to an active flag used in an idle state is received through the TAU receiving unit in an activated state of the data service for the subscriber station.

The mobility management apparatus may further include an initial setting request unit for requesting the subscriber station to set an initial context when a message set to an active flag used in an idle state is received through the TAU receiving unit.

The above-described mobility management apparatus may further include a response message transmission unit for transmitting an initial context setup response message to the interface ratio.

According to another aspect of the present invention, there is provided a signal control method performed by a mobility management apparatus, comprising: receiving a TAU request message in which an active flag is set through an inode ratio; And when a message set to an active flag used in an idle state is received by a TAU request message receiving step in an active state of a data service for a subscriber terminal, it is determined that the corresponding radio terminal is temporarily disconnected from the corresponding subscriber terminal, The method comprising the steps of:

The signal control method may further include requesting an initial context setting to a subscriber station when a message set in an active flag used in an idle state is received by a TAU request message receiving step.

The above-described signal control method may further include transmitting an initial context setup response message to the inode ratio.

According to the present invention, when a temporary radio link disconnection occurs during the use of the terminal data service, even if the MME receives the TAU set to the active flag (0) used in the idle state from the eNodeB, It is possible to prevent the service from being disconnected.

1 is a diagram illustrating a general LTE system.
FIG. 2 is a diagram for explaining an LTE system according to an embodiment of the present invention. In a situation where a temporary radio link disconnection occurs while using a terminal data service, when the MME receives an active flag 0 ) Of the TAU is received.
3 is a diagram schematically showing the configuration of a mobility management apparatus according to an embodiment of the present invention.

Hereinafter, an LTE system, a mobility management apparatus, and a signal control method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a general LTE system.

1, when a UE (User Equipment) 10 uses a data service of an EPC (Evolved Packet Core) network through a Serving / Packet Date Network Gateway (SPGW) 40, a radio link disconnection (RLF) The RRC connection re-establishment request signal transmitted from the UE 10 to the eNBs 20 is rejected by the eNBs 20. In this case, (S101, S103). In this case, the terminal 10 requests the eNBs 20 to make an RRC connection to recover the radio link disconnection (S105), establishes an RRC connection from the eNBs 20 (S107) A message indicating that the RRC connection is completed is transmitted (S109). At this time, when the temporary radio link disconnection occurs, the terminal 10 uses the TAU (Tracking Area Update) set to the active flag (0) used in the idle state instead of the active flag 1 corresponding to the radio link disconnection ) Message to the eNBs 20.

the eNBs 20 transit from the active state to the idle state by radio link disconnection to the terminal 10 and transmit the TAU message received from the terminal 10 to the mobility management entity (MME) 30 (S111).

When the TAU message set in the active flag 0 used in the idle state is received from the eNBs 20 while the data service for the AT 10 is active, the mobility management apparatus 30 transmits the TAU message to the AT 10 Transmits a downlink NAS (Network Access Server) indicating that the corresponding TAU message is accepted (S113). In addition, the mobility management apparatus 30 requests the SPGW 40 for a Release Access Bearer in response to the TAU message received via the eNBs 20 (S115). At this time, the mobility management apparatus 30 receives the release access bearer response signal from the SPGW 40 (S117). a context release command for the terminal 10 is transmitted to the eNBs 20 in step S119 and a context release completion signal for the terminal 10 is received from the eNBs 20 in step S121.

In the LTE system as described above, the mobility management apparatus 30 and the SPGW 40 are configured such that the mobility management apparatus 30 is able to communicate with the eNBs 20 Corresponding to the TAU message set to the active flag (0) used in the idle state, correspondingly corresponding to the release request bearer for the SPGW 40 and the release command for the eNBs 20 and the completion signal The mobility management apparatus 30 and the SPGW 40 are also transited to the idle state by the reception process, thereby causing the data service for the terminal 10 to be disconnected.

FIG. 2 is a diagram for explaining an LTE system according to an embodiment of the present invention. In a situation where a temporary radio link disconnection occurs while using a terminal data service, an MME transmits an active flag 0 ) Of the TAU is received.

2, when a wireless link disconnection occurs while the terminal 110 is using the data service of the EPC network via the SPGW 140, the terminal 110 transmits an RRC connection re- Is rejected by the eNBs 120 (S201, S203). In this case, the UE 110 requests the eNBs 120 to establish an RRC connection to recover the radio link disconnection (S205), establishes an RRC connection from the eNBs 120 (S207) A message indicating that the RRC connection is completed is transmitted (S209). In this case, when the temporary radio link disconnection occurs, the UE 110 transmits a TAU message set to an active flag (0) used in the idle state instead of the active flag 1 corresponding to the radio link disconnection to the eNBs 120).

The eNBs 120 transit from the active state to the idle state by a temporary radio link disconnection to the terminal 10 and transmit the TAU message received from the terminal 10 to the mobility management apparatus 130 at step S211.

The mobility management apparatus 130 is set to the active flag 0 used in the idle state from the eNBs 120 in a state where the data service for the terminal 110 is active, TAU message is received, it is judged to be a temporary radio link disconnection for the corresponding terminal 10, and the TAU set as the active flag 1 is received. That is, the mobility management apparatus 130 permits the TAU message and transmits an initial context setting request signal to the UE 110 in step S213 and transmits an initial context setting response signal to the eNBs 120 in step S215. In addition, the mobility management apparatus 130 requests the SPGW 140 to perform a bearer reset in terms of the radio side and the EPC (S217), receives the bearer reset response signal from the SPGW 140 accordingly, and recovers the service (S219 ). Accordingly, the terminal 110, the eNBs 120, the mobility management apparatus 130, and the SPGW 140 remain active and can continue the data service for the terminal 110. Here, the active flag (0) and the active flag (1) are flags defined in the NAS (Network Access Server) protocol, the active flag (0) is a flag indicating the idle state, Lt; / RTI >

3 is a diagram schematically showing the configuration of a mobility management apparatus according to an embodiment of the present invention. The mobility management apparatus according to the embodiment of the present invention can be used as the MME 130 of the LTE system shown in FIG. 2, and therefore gives the same reference numerals.

3, the mobility management apparatus 130 includes a TAU receiving unit 132, a bearer resetting unit 134, an initial setting request unit 136, and a response message transmitting unit 138 can do.

The TAU receiving unit 132 receives the TAU request message in which the active flag is set through the inode bids (eNBs)

When the message set in the idle state is received via the TAU receiving unit 132 in the active state of the data service for the subscriber terminal 110, the bearer resumption unit 134 notifies the corresponding subscriber terminal 110 (RAB) side and the EPG side to the gateway (SPGW) 140. In this case,

The initial setting request unit 136 requests the subscriber terminal 110 to set an initial context when a message set in the active flag used in the idle state is received through the TAU receiving unit 132. [ That is, the initialization request unit 136 receives the TAU message set to the active flag (0) used in the idle state from the eNBs 120 in the same state as the temporary radio link disconnection during the data service for the UE 110 , It is determined that the radio link is temporarily disconnected and the TAU set as the active flag (1) is received.

The response message transmission unit 138 transmits an initial context setup response message to the eNBs 120. That is, the response message transmitter 138 transmits an initial context setup response message to the eNBs 120 to initialize the information about the UE 110. [

Claims (8)

In an LTE (Long Term Evolution) system,
When receiving a message set to an active flag used in an idle state through an evolved Node B (eNB) in an active state of a data service for a subscriber station, A device (MME: Mobility Management Entity); And
A gateway for performing a bearer reset if the bearer re-establishment is requested by the mobility management apparatus;
Gt; LTE < / RTI > The method according to claim 1,
The mobility management apparatus comprising:
Requesting an initial context setting to the subscriber station when a message set to an active flag used in an idle state is received through the inode ratio and transmitting an initial context setting response message to the inode bee. LTE systems. A mobility management apparatus comprising:
A TAU receiving unit that receives a TAU (Tracking Area Update) request message that sets an active flag through an inode ratio; And
A bearer reconfiguration unit for requesting a gateway to re-establish a bearer when a message set to an active flag used in an idle state is received through the TAU receiving unit in an activated state of a data service for a subscriber station;
The mobility management apparatus comprising: The method of claim 3,
An initial setting request unit for requesting an initial context setting to the subscriber station when a message set to an active flag used in an idle state is received through the TAU receiving unit;
The mobility management apparatus further comprising: 5. The method of claim 4,
A response message transmitter for transmitting an initial context setup response message to the inode bee;
The mobility management apparatus further comprising: A signal control method performed by a mobility management apparatus,
Receiving a TAU request message that sets an active flag through the inode ratio; And
Requesting a gateway to perform a bearer reset if a message set to an active flag used in an idle state is received by the TAU request message receiving step in an active state of a data service for a subscriber terminal;
Wherein the signal control method comprises: The method according to claim 6,
Requesting an initial context setting to the subscriber station when a message set to an active flag used in an idle state is received by the TAU request message receiving step;
≪ / RTI > 8. The method of claim 7,
Transmitting an initial context setup response message to the inode fee;
≪ / RTI >

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