KR20180069471A - LTE bearer connection control method and apparatus - Google Patents

Abstract

The present invention relates to a method and a device for controlling LTE bearer connection. According to an embodiment of the present invention, a mobility management entity (MME) comprises a communication unit and a control unit. The communication unit receives a radio resource control (RRC) connection requesting signal for RRC protocol connection of a terminal from the terminal or a base station. The control unit determines whether or not an establishment cause included in the RRC connection requesting signal is identification information (mo-VData) for indicating voice over LTE (VoLTE). The control unit is able to assign a priority of LTE bearer connection to the terminal corresponding to the identification information. The present invention is able to improve quality of a voice call, which is a basic service of a terminal.

Description

[0001] LTE bearer connection control method and apparatus [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LTE bearer connection control method, and more particularly, to a LTE bearer connection control method and apparatus considering an Establishment Cause of a wireless LTE network connection.

The LTE (Long Term Evolution) network is divided into the LTE (E-UTRAN) related technologies and the EPC (Enhanced Packet Core) . Since the LTE network is an E2E all-IP network, all traffic flows from a wireless link that a user terminal connects to a base station to a packet data network (PDN) that connects to a final service provider operate on an IP basis.

When a user who has purchased an LTE terminal (UE, User Equipment) subscribes to a mobile communication service provider (hereinafter referred to as a "service provider") network, the service type and the fee type are selected, and the subscriber profile to control the subscriber's use of the service.

In recent years, a user terminal is an intelligent terminal that adds functions supported by a computer, such as Internet communication and information retrieval, and is installed with an application desired by a user, and such a user terminal can often be referred to as a smart phone .

A user can additionally install an application that performs various functions in a user terminal. Such applications can be provided through a wireless communication function such as LTE communication, a broadcasting service such as e-mail, web browsing, Internet shopping or banking, , A camcorder, and an MP3 function. Such an application can periodically access the wireless communication network and perform data communication for performing each function even if there is no direct control by the user. As the number of applications installed in the user terminal increases, the amount of data communication required by each application may increase.

On the other hand, a wireless communication network (for example, an LTE network) is faster than a network connection by the application and a UE-triggered service request by the application, Quot; service request " for a service (for example, a voice call) that is required. That is, the wireless communication network has to handle the frequent " UE-triggered service request " related to wireless communication that the user of the terminal does not want immediately.

However, considering the user's intention, voice call service should be preferentially processed in comparison with other data communication because real-time data processing is important. Specifically, when the wireless communication network is congested or overloaded (for example, in a disaster situation), the wireless communication network may preferentially process data transmission and reception associated with the user's voice call but may not.

Therefore, a wireless communication network needs a method that can prioritize data processing related to a voice call among the causes of a request for a wireless communication service.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an LTE bearer connection control method and apparatus.

In detail, the present invention identifies an LTE network connection related to Voice over LTE (VoLTE) using a wireless communication network and an LTE network connection for general data communication other than the above, and selectively connects to a wireless communication network selectively The present invention provides a method and apparatus for controlling an LTE bearer connection.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

According to an aspect of the present invention, there is provided a Mobility Management Entity (MME) according to an exemplary embodiment of the present invention. The MME includes a Radio Resource Control (RRC) A communication unit for receiving a connection request signal; And a controller for determining whether an Establishment Cause included in the RRC connection request signal is identification information mo-VData indicating Voice over LTE (VoLTE). The control unit may give priority to an LTE bearer connection to a terminal corresponding to the identification information.

According to the embodiment, the control unit may shorten the backoff time of the LTE bearer connection with respect to the identification information.

According to an embodiment, when the wireless communication network is in a congested state, it may increase the backoff time of the LTE bearer connection to the terminal that does not correspond to the identification information.

According to an embodiment of the present invention, when the wireless communication network is in a congested state, the controller stops an LTE bearer connection request to a terminal not corresponding to the identification information for a predetermined time, And send a request signal for connection to the Serving Gateway (S-GW).

According to an embodiment, the controller may determine that the wireless communication network is in a congestion state when the number of times the request signal for the LTE bearer connection is received is equal to or greater than a threshold value.

In addition, an LTE bearer connection control method of a Mobility Management Entity (MME) according to an exemplary embodiment of the present invention includes: receiving a RRC connection request for connection of a Radio Resource Control (RRC) Receiving a signal; Determining whether an Establishment Cause included in the RRC connection request signal is identification information mo-VData indicating Voice over LTE; And assigning a priority of an LTE bearer connection to a terminal corresponding to the identification information; . ≪ / RTI >

According to an embodiment, the step of giving priority includes: shortening a backoff time of an LTE bearer connection to the identification information; . ≪ / RTI >

According to an embodiment, the step of granting a priority may include: increasing a backoff time of an LTE bearer connection to a terminal that does not correspond to the identification information when the wireless communication network is in a congested state; . ≪ / RTI >

According to an embodiment, the step of granting the priority may include: stopping an LTE bearer connection request to a terminal not corresponding to the identification information for a predetermined time when the wireless communication network is in a congested state; Transmitting a request signal for connection of an LTE bearer to a terminal corresponding to the identification information to an S-GW (Serving Gateway); . ≪ / RTI >

Determining that the wireless communication network is in a congested state when the number of times the request signal for the LTE bearer connection is greater than or equal to a threshold; As shown in FIG.

According to the embodiment, the present invention can provide a computer-readable recording medium on which a program for executing the above-described method is recorded.

Advantages of the LTE bearer connection control method and apparatus according to the present invention are as follows.

First, the present invention can identify the establishment cause of the network connection of the terminal and determine the priority of the network connection according to the policy.

Second, the present invention can improve the quality of a voice call as a basic service of a terminal by prioritizing a network connection for a voice call.

Third, the present invention can provide a faster voice call service by prioritizing LTE network connection related to Voice over LTE (VoLTE) using a wireless communication network in a network overload state such as a disaster situation.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. It is to be understood, however, that the technical features of the present invention are not limited to the specific drawings, and the features disclosed in the drawings may be combined with each other to constitute a new embodiment.
1 is a block diagram of an LTE network for facilitating understanding of the present invention.
FIG. 2 is a view for explaining traffic flows on an LTE network for facilitating understanding of the present invention. FIG.
3 is a diagram for explaining an IP address assignment method in an LTE network for facilitating understanding of the present invention.
FIG. 4 is a diagram for explaining an IP address assignment procedure to help understand the present invention.
FIG. 5 is a view for explaining the establishment cause according to an embodiment of the present invention.
6 is a diagram for explaining an LTE bearer connection control method according to an embodiment of the present invention.
7 is a diagram for explaining an LTE bearer connection control method according to another embodiment of the present invention.
8 is a flowchart illustrating an LTE bearer connection control method according to another embodiment of the present invention.
9 is a block diagram illustrating an LTE bearer connection control apparatus according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and various methods to which embodiments of the present invention are applied will be described in detail with reference to the drawings. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

1 to 4, a general LTE network will be described, and a LTE bearer connection control method and apparatus will be described in detail with reference to FIGS. 5 to 9. FIG.

1 is a configuration diagram of an LTE network according to the present invention.

1, an LTE network includes a UE (User Equipment) 10, an Evolved Node B (eNB) 20, an S-GW (Serving Gateway) 30, a Packet Data Network Gateway An MCS (Mobility Management Entity) 50, an HSS (Home Subscriber Server) 60, an SPR (Subscriber Profile Repository) 70, an OFFCS (Offline Charging System) 80, an OCS (Online Charging System) (Policy and Charging Rule Function, 100).

The UE 10 is an LTE user terminal and is connected to the eNB 20 via the LTE Uu air interface 15. [ Here, the LTE Uu interface 15 defines a control plane for transmitting and receiving a control message as a wireless interface and a user plane for providing user data.

The eNB 20 provides a radio interface to the UE 10 and provides radio resource management functions such as radio bearer control, radio admission control, dynamic radio resource allocation, load balancing and inter-cell interference control do.

The S-GW 30 is an end point of an evolved universal terrestrial radio access network (E-UTRAN) and an evolved packet core (EPC), and an anchor point at handover between the eNB 20 and the 3GPP system do. Here, the E-UTRAN comprises at least one eNB 20, and the EPC may include an S-GW 30, a P-GW 40 and an MME 50.

The P-GW 40 connects the UE 10 to an external PDN (Packet Data Network) 110 and performs a packet filtering function. In addition, the P-GW 40 assigns an IP address to the UE 10 and operates as a mobility anchoring point when performing handover between the 3GPP system and the non-3GPP system. In particular, the P-GW 40 receives the Policy and Charging Control (PCC) rule from the PCRF 100, applies it to the corresponding service flow, and provides the billing function per UE 10 / SDF (Service Date Flow) do.

The MME 50 communicates with the HSS 60 for user authentication and downloading of user profiles as a mobility management entity of the E-UTRAN and provides EPS mobility management (EMM) and EPS session management (ESM) to the user terminal through NAS signaling. Function. In detail, the MME 50 manages connection and release of an EPS radio bearer to the terminal and performs authentication, security key management, paging, and allocation of an IP address of the terminal, do. The Evolved Packet System (EPS) may include E-UTRAN (LTE Radio Access Network) and EPC (LTE Core Network).

The HSS 60 provides a user profile and a user profile to the MME 50 as a database of subscriber profiles.

The SPR 70 provides subscriber and subscription related information to the PCRF 100, and the PCRF 100 generates subscriber based PCC rules using the subscriber and subscription related information.

OFCS 80 provides charging information based on CDR (Charging Data Record).

OCS 90 provides volume, time, and event-based billing functions through real-time credit control.

The PCRF 100 provides policy control decisions and billing control functions as entities that perform policy and billing control. The PCC rules generated in the PCRF 100 are transmitted to the P-GW 40.

Hereinafter, the interface between the elements constituting the LTE network will be briefly described.

The LTE-Uu 15 provides a control plane and a user plane with a radio interface between the UE 10 and the eNB 20. [

The S1-U 25 is an interface between the eNB 20 and the S-GW 30, and provides a user plane. At this time, GTP tunneling per bearer is provided.

S5 35 is an interface between the S-GW 30 and the P-GW 40, providing a control plane and a user plane. At this time, the user plane provides bearer-specific GTP tunneling, and the control plane provides GTP tunnel management.

SGi 45 defines a user plane and a control plane as an interface between the P-GW 40 and the PDN 110. In the user plane, IETF based IP packet forwarding protocol is used, and in the control plane, protocols such as DHCP and RADIUS / Diameter are used.

S11 55 defines a control plane as an interface between the MME 50 and the S-GW 30, and GTP tunneling per bearer is provided.

X2 65 is an interface between the two eNBs 20, providing a control plane and a user plane. The X2-AP protocol is used in the control plane and the GPRS tunneling protocol (GTP) per bearer for data forwarding in the X2 handover in the user plane.

S6a (75) is provided with a control plane as an interface between the HSS 60 and the MME 50, and is used for exchanging UE subscription information and authentication information.

The Gx 85 is an interface between the PCRF 100 and the P-GW 40. The control plane is defined and used to convey policy control rules and billing rules for QoS (quality of service) policy and billing control .

Sp (95) is an interface between the SPR 70 and the PCRF 100, in which a control plane is defined and used to convey a user profile.

Gz 105 is an interface between the OFCS 80 and the P-GW 40 and defines a control plane and is used for CDR transmission from the P-GW 40 to the OFCS 80. [

Gy 115 is an interface between the OCS 90 and the P-GW 40. The control plane is defined and used for real-time credit control information exchange.

FIG. 2 is a view for explaining traffic flows on an LTE network for facilitating understanding of the present invention. FIG.

More specifically, Figure 2 shows the Internet traffic flow in the user plane of the LTE network reference model. Reference numeral 200a denotes a traffic flow from the UE 10 to the Internet, hereinafter referred to as "uplink traffic flow", 200b denotes a traffic flow from the Internet to the UE 10, hereinafter referred to as " Business card.

IP packets are transmitted over the GTP tunnel on the S1-U (25) and S5 (35) interfaces, respectively. Here, the GTP tunnel is set for each EPS bearer through control signaling when the UE 10 initially connects to the LTE network.

Since several EPS bearers are set on one of the S1-U 25 and the S5 (35) interfaces, a tunnel endpoint identifier (TEID) is allocated upwardly and downwardly in each GTP tunnel establishment to distinguish them. When a GTP tunnel is set in the S1-U (25) interface, a TEID (UL S1-TEID) having an end point is allocated to the S-GW 20 upward and a TEID (DL S1-TEID) having an end point is allocated to the eNB 20 -TEID). Similarly, when a GTP tunnel is established in the S5 (35) interface, a TEID (UL S5-TEID) having an end point in the P-GW 40 and a TEID (DL S5-TEID) having an end point in the S- S5-TEID).

The eNB 20, the S-GW 30 and the P-GW 40 transmit a GTP tunnel header to the GTP packet header when the user IP packet is transmitted through the GTP tunnel on the S1-U 25 and the S5 When it is generated, it inserts the allocated TEID and transmits it. The S-GW 30 must have mapping information between the UL S1-TEID and the UL S5-TEID in order to terminate the S1-GTP tunnel in the upward direction and to transmit the user IP packet to the S5-GTP tunnel. Likewise, in the downlink, mapping information between DL S5-TEID and DL S1-TEID must be maintained.

Hereinafter, referring to FIG. 2, a procedure for each entity to process uplink and downlink Internet traffic flows will be described in detail.

First, in the uplink, the UE 10 transmits internally generated user IP packets to the eNB 20 via the LTE-Uu 15 interface. The eNB 20 constructs an S1 GTP header having the S-GW IP address as the destination address, the eNB 20 address as the originating address, the UL S1-TEID as the TEID, and adds the S1 GTP header to the received user IP packet. To the S-GW 30.

When receiving the user IP packet through the S1 GTP tunnel, the S-GW 30 transmits the IP address of the P-GW 40 to the destination address, the S-GW 30 to the originating address, and the UL S5-TEID to the S5 Configure the GTP header. Then, the S5 GTP header is added to the user IP packet and transmitted to the P-GW 40 through the S5 GTP tunnel.

Subsequently, the P-GW 40 controls the S5 GTP header to extract user IP packets, and then transmits them to the Internet through IP routing.

Referring to the downlink traffic flow, the P-GW 40 receives a user IP packet directed to the UE 10 via the Internet. The P-GW 40 adds the S5 GTP header having the S-GW IP address as the destination address, the P-GW IP address as the sending address and the DL S5-TEID as the TEID to the user IP packet, To the S-GW 30.

The S-GW 30 adds the eNB IP address to the destination IP address, the source address of the S-GW IP address, and the S1 GTP header including the DL S1-TEID with the TEID to the user IP packet received through the S5 GTP tunnel, To the eNB 20 via the GTP tunnel.

The eNB 20 transmits the user IP packet from which the S1 GTP header has been removed to the UE 10 via a data radio bearer (DRB), which is a bearer on the radio link.

It should be noted that the GTP tunnel shown in FIG. 2 is a user plane GTP tunnel for transmitting a user IP packet, hereinafter referred to as a " GTP-U tunnel ".

3 is a diagram for explaining an IP address assignment method in an LTE network for facilitating understanding of the present invention. More specifically, FIG. 2 illustrates a method for allocating an IP address to a user terminal in a LTE network when a user terminal accesses an LTE network in the LTE network. The method includes a Dynamic IP Address Allocation ) Method and a static IP address allocation method.

Generally, the UE 10 requests a connection of the PDN 110 to the LTE network upon initial connection to the LTE network. The P-GW 40 assigns an IP address - that is, a PDN address - to be used by the UE 10 to provide the PDN 110 connection to the UE 10 and delivers it to the UE 10. Here, the PDN address is transmitted from the P-GW 40 to the UE 10 in the process of setting a default bearer between the P-GW 40 and the UE 10, and the UE 10 transmits the PDN The PDN 110 can access the service provided by the PDN 110 using the address.

The P-GW 40 allocates an IP address to the UE 10 by a dynamic IP address allocation method that is dynamically generated each time the UE 10 accesses the LTE network, There is a fixed IP address assignment method in which the subscriber profile stored in the HSS 60 is referred to when the UE 10 connects to the LTE network.

More specifically, as shown in FIG. 3, when a UE accesses an LTE network after a provider configures an IP pool in the P-GW 40 in advance, And assigns an IP address dynamically.

On the other hand, in the fixed IP address assignment method, when a user joins a service provider network, a service provider allocates an IP address to be permanently used to the UE 10 and maintains the IP address in the HSS 60. When the UE 10 accesses the LTE network, The GW 40 receives the IP address corresponding to the UE 10 from the HSS 60 and delivers the IP address to the UE 10. [

The UE 10 may request predetermined protocol information related to an external protocol and an application using a Protocol Configuration Option (PCO) parameter in a process of requesting a PDN connection when initially accessing an LTE network. Here, the protocol information may include a DNS server address.

The details of the above-mentioned PCO will be described in detail in 3GPP TS 24.008.

FIG. 4 is a diagram for explaining an IP address assignment procedure to help understand the present invention. More specifically, FIG. 4 is a diagram for explaining a static IP address assignment procedure.

Referring to FIG. 4, the UE 10 transmits a PDN Connectivity Request message to the MME 50 when the UE 10 is powered on (S401). At this time, the PDN connection request message may include information such as International Mobile Station Identity (IMSI), PDN type = IPv4, and PCO = DNS Server IPv4 Address Request. Here, IMSI is unique identification information for identifying a subscriber in the LTE network.

The MME 50 transmits a Location Update Request message including the IMSI to the HSS 60 (S403).

The HSS 60 inquires of the subscriber profile corresponding to the IMSI from the internal database and transmits to the MME 50 a Location Update Answer Message including a fixed IP address allocated in advance to the corresponding subscriber (S405) .

The MME 50 includes a session creation request including a fixed IP address received from the HSS 60 and an International Mobile Subscriber Identity (IMSI) received from the UE 10, PDN type = IPv4, PCO = DNS Server IPv4 Address Request, (Create Session Request Message) to the S-GW 30 (S407).

Subsequently, the S-GW 30 transmits the received session creation request message to the P-GW 40 (S409).

Thereafter, in response to the request message in steps 409 and 407, the P-GW 40 and the S-GW 30 send a Create Session Response message to the MME 50 send. Here, the session creation response message may include the fixed IP address in the PDN address field and the DNS server IP address requested by the user in the PCO field.

The MME 50 transmits an Activate Default EPS Bearer Context Request message including a static IP address and a DNS IP address, wherein the DNS IP address may include a primary DNS IP address and a secondary DNS IP address. To the UE 10 (S415). Here, the default EPS bearer activation request message, which is one of the EPS session management messages (hereinafter referred to as "ESM (EPS Session Management) messages"), is an EPS mobility management message. May be included in the "Attach Accept Message" called "EMM (EPS Mobility Management) message".

Thereafter, a fixed IP address and a DNS IP address are stored in the internal memory of the UE 10 (S417), and a default EPS bearer is set between the UE 10 and the P-GW 40 (S419). At this time, the UE 10 can access the PDN 110 through the set default EPS bearer and transmit / receive user IP packets.

Hereinafter, policy and accounting control in an LTE network will be briefly described.

The PCRF 100 determines the PCC rules for each service data flow (SDF) and transmits the determined PCC rules to the PCF (Policy and Charging Enforcement Function) (for example, P-GW 40). Here, the PCC rule can be determined based on a provider policy - for example, QoS policy, gate status, billing method, and the like. The PCC rules may also include information on detection of packets belonging to a particular SDF, identification of the service, accounting parameters to be applied to the SDF, and policy control on the SDF.

The PCRF 100 generates a predetermined packet filter (e.g., SDF template) for detecting which SDF the user IP packets transmitted and received on the SGi 45 interface correspond to, Can be applied to rules. In addition, the P-GW 40 can bind the SDF QoS and the LTE bearer QoS using the PCC rules received from the PCRF 100, and then reflect the SDF QoS and the LTE bearer QoS on the EPS bearer.

Here, the SDF template is included in the above PCC rule. The SDF template consists of a source IP address, a destination IP address, a source port, a destination port, and a protocol identifier for each of the uplink and the downlink. Is a 5-tuple based SDF delimiter (Classifire).

In general, there may be a plurality of IP flows or a " Service Flow " depending on the application service used by one UE or depending on the type of traffic transmitted and received. For example, an application service may include a Naver connection, a next connection, a Kakao Talk, a game, VoIP, YouTube, and the like. These IP flows can be mapped to SDF using a 5-tuple-based SDF template. As described above, when a plurality of IP flows are classified into 5-tuple-based SDFs, the P-GW 40 can process the QoS for each SDF and map the corresponding SDF to the EPS bearer.

FIG. 5 is a view for explaining the establishment cause according to an embodiment of the present invention.

The attachment process can be performed when the context information of the user terminal (e.g., information for identifying the user terminal, IP information, etc.) is not stored in the LTE network.

Referring to FIG. 5, the initial attaching process in the E-UTRAN includes steps of performing identification, authentication, security verification, etc. through interaction with a user terminal (hereinafter referred to as " terminal & Establishing a tunnel between the network side and the user terminal, and establishing a default bearer at the network side after establishing a tunnel between the network side and the user terminal.

In order for the terminal 10 to request initial attachment to the LTE network, a communication connection with the base station 20 is indispensable. First, the terminal 10 can select the base station 20 through a PLMN (Public Land Mobile Network) selection, and can perform wireless connection synchronization through a cell search procedure. After completing the synchronization for communication connection with the base station 20, the terminal 10 can establish a communication connection with the base station 20. At this time, the terminal 10 may be in the unregistered state of the EMM, and the ECM and RRC connection may be in the idle state. The terminal 10 may transmit a message of the RRC layer via an RRC connection or may transmit a message to another upper layer (e.g., the NAS layer) to the base station 20 or the LTE network.

The terminal 10 can transmit an RRC connection request signal to the base station 20 for RRC connection between the terminal 10 and the base station 20. [ The RRC connection request signal may include an Establishment Cause that can identify the type of the service requested by the terminal 10 as a cause of requesting the network connection.

The Establishment Cause can be prioritized, and the priority can be set according to the Access class (AC) value set for the establishment cause. For example, AC may be a value between 0 and 15, with 0 to 9 being used for general purposes by general subscribers, and 11 to 15 being used for specific purposes.

Specifically, the terminal 10 can have an AC value of "Mobile Originating Signaling (mo-Data)" as its establishment cause. In general, "Mobile Originating Signaling May be the establishment cause used to perform the attachment process to the base station 20 for data communication or to release the attachment. The RRC connection request signal may be transmitted through a Signaling Radio Bearer (SRB) 0, which is a common control channel (CCCH) allowed to all the UEs 10 in the cell.

The base station 20 can control radio resource allocation for uplink or downlink traffic flows. When the base station 20 receives an RRC connection request signal from the terminal 10, it can allocate SRB 1. Thereafter, the base station 20 may transmit an RRC connection setup signal (RRC Connection Setup) to the terminal 10 through SRB 0. The terminal 10 can then use the radio resources through the allocated SRB.

The terminal 10 may receive the RRC connection setup signal and may transmit the RRC Connection Setup Complete via the dedicated channel SRB1.

Considering the transmission efficiency, the AT 10 may transmit the ATTACH request to the MME 50 through the NAS layer. The AT 10 may transmit the ATTACK request signal when the RRC setup completion signal is transmitted. have. The attachment request signal may include NAS information.

The base station 20 and the MME 50 can transmit and receive control signals through a specific interface (S1-U, S1-MME interface). The base station 20 may transmit an initial UE message 10 including the NAS information included in the attachment request signal. The initial terminal message may also include information included in the attachment request message.

The MME 50 may receive the initial terminal 10 message and establish an S1 communication connection with the base station 20 and the terminal 10 may complete the ECM connection.

The MME 50 may then send a Bearer Connection Request for the LTE bearer connection to the S-GW 30. The request signal for the bearer connection may be a Create Session Request. The MME 50 can provide an environment in which the terminal 10 requesting the attachment can perform data communication through the LTE network by transmitting a request signal for bearer connection.

On the other hand, 0 through 9 can be used for general data communication purposes except for the values used for specific purposes such as 11 through 15 of the establishment cause (AC). The present invention can be applied to general data (Mo -Vdata) for distinguishing voice calls aimed at Voice over LTE (VoLTE), and prioritizing network connections other than voice call data for VoLTE, thereby improving VoLTE's call quality .

In particular, it aims to prioritize network communication connections for VoLTE voice calls over other common data communications in a congested network environment, such as a disaster situation.

6 is a diagram for explaining an LTE bearer connection control method according to an embodiment of the present invention.

The network may be overloaded (e.g., "congested"). For example, network overload can occur at certain times (e.g., at work) or in certain events (e.g., disaster situations such as earthquakes).

Meanwhile, the network can reject the request of the terminal requesting connection to the network. Then, the network can provide a wait time value to the terminal while the terminal is not allowed to reconnect with the network.

If it is determined that the network is in an overload state, the network can stop the bearer setup for connection to the LTE network for a predetermined period of time without performing the bearer setup.

Referring to FIG. 6, a terminal A requests a VoLTE service to a network, and a terminal B requests a data communication other than a VoLTE service to a network.

The establishment cause contained in the RRC connection request signal of the terminal A is "mo-VData " indicating the VoLTE service and the establishment cause of the terminal B is" mo-Data " The base station 20 may receive the information and transmit information on the establishment cause to the MME 50.

The MME 50 can simultaneously receive the network connection request signal according to the RRC connection request of the terminal A and the terminal B. If the network is not congested and can perform all the network connections of the terminal A and the terminal B And can transmit a signal for each network connection to the S-GW 30.

However, when the MME 50 determines that the network is in a congested state, the MME 50 selects a connection to the LTE network and transmits a connection request signal (bearer connection request signal) to the LTE network have.

The MME 50 can determine that the wireless communication network is in a congested state when the number of times of receiving the request signal (LTE bearer connection request signal) for connection to the LTE network is equal to or larger than the threshold value.

However, the threshold value setting is not limited to the MME 50 but may be applied to at least one of the MME 50, the S-GW 60, and the P-GW node included in the EPC, Can be set.

The MME 50 may increase the backoff time of the LTE bearer connection for connection to the LTE network to a terminal that does not correspond to the identification information when the wireless communication network is in a congested state.

In general, there may be a terminal requesting connection to an LTE network in only one cell. When a plurality of terminals attempt to access the network at the same time, the load of the wireless communication network may instantaneously increase. This situation can make the wireless network unstable and interfere with the initial connection of other terminals.

When the load of the wireless communication network exceeds a certain threshold value, the load can be controlled by suppressing the initial connection of the terminals requesting connection to the LTE network. In the present invention, the MME 50 notifies the terminal requesting the VoLTE service to the VoLTE service (step < RTI ID = 0.0 > It is possible to give priority to the connection of the network to the terminal requesting other services. Of course, according to the policy of the service provider, the MME 50 can change the cause of establishing the priority from VoLTE service to another service.

In one embodiment, the MME 50 identifies a terminal requesting a VoLTE service and a terminal requesting a service other than a VoLTE service, and notifies a terminal requesting a VoLTE service to a terminal requesting a service other than a VoLTE service A short backoff time can be indicated. On the contrary, the MME 50 may instruct a terminal requesting a service other than the VoLTE service to have a longer backoff time for a terminal requesting the VoLTE service.

In another embodiment, the MME 50 may identify a terminal requesting a VoLTE service, shorten the backoff time set in advance, and give priority to the terminal. Alternatively, the MME 50 may assign a priority to a terminal requesting a service other than the VoLTE service The backoff time previously set for the wireless communication network can be extended to lower the priority of the connection of the wireless communication network.

7 is a diagram for explaining an LTE bearer connection control method according to another embodiment of the present invention.

Referring to FIG. 7, in a state where a communication channel is established between the UE and the MME 50, the UE can request a new network service according to the UL traffic flow. The terminal may transmit a new service request signal to the network through the MME 50, and the service request signal may include a cause for establishment of the network connection.

The terminal A is a terminal requesting a VoLTE service to the network, and the terminal B is a terminal requesting data communication other than the VoLTE service to the network.

The establishment cause contained in the service request signal of the terminal A is "mo-VData " indicating the VoLTE service and the establishing cause of the terminal B is" mo-Data "

When the MME 50 simultaneously receives the LTE network connection request signal of the terminal A and the terminal B in the congested state of the network, the MME 50 preferentially transmits the network connection request signal to the S-GW 30 for the terminal requesting the VoLTE service Lt; / RTI >

A predetermined waiting time can be set for a terminal requesting a general LTE network service other than the VoLTE service like the terminal B and a request signal for network connection can be transmitted in a rearranged manner after the waiting time elapses.

8 is a flowchart illustrating an LTE bearer connection control method according to another embodiment of the present invention.

Referring to FIG. 8, the MME may receive an RRC connection request signal for connection of a radio resource control protocol from a terminal or a base station (S810).

The MME can determine whether the establishment cause included in the RRC connection request signal is the identification information (mo-VData) indicating VoLTE (S820).

When the MME receives the RRC connection request signal more than a predetermined number of times, it can determine that the LTE network is in a congested state, and the MME can give priority to the LTE bearer connection to the terminal corresponding to the identification information (mo-VData) (S830).

The MME suspends the LTE bearer connection request to the S-GW for the terminal not corresponding to the identification information for a predetermined time or increases the waiting time included in the response to the RRC connection request signal, And the like.

9 is a block diagram illustrating an LTE bearer connection control apparatus according to another embodiment of the present invention.

9 are not essential, an LTE bearer connection control apparatus 900 having more or fewer components can be implemented. In one embodiment, the LTE bearer connection control apparatus 900 may be an MME.

The communication unit 910 may transmit and receive a control signal for connection to a terminal or a base station and a wireless network.

In one embodiment, the communication unit 910 may receive an RRC connection request signal for connection of a radio resource control (RRC) protocol of the UE.

The control unit 520 may perform data processing and operations to control the LTE bearer connection control apparatus 900. [

The control unit 520 determines whether the Establishment Cause included in the RRC connection request signal is the identification information mo-VData indicating VoLTE (voice over LTE), and transmits the LTE bearer bearer connection. If the number of times of receiving the request signal for the LTE bearer connection is equal to or greater than the threshold value, it is determined that the wireless communication network is in a congested state, and a request signal for each LTE bearer connection is transmitted to the S-GW 30 Lt; / RTI >

The memory 530 is a generic name of a space and / or a storage area where predetermined program codes for controlling the overall operation of the IOT hub 500 and data to be input / output when the program code is operated are stored , An EEPROM (Electrically Erasable and Programmable Read Only Memory), an FM (Flash Memory), a hard disk drive, and the like.

The method according to the above-described embodiments may be implemented as a program to be executed by a computer and stored in a computer-readable recording medium. Examples of the computer-readable recording medium include a ROM, a RAM, a CD- , A floppy disk, an optical data storage device, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet).

The computer readable recording medium may be distributed over networked computer servers so that computer readable code can be stored and executed in a distributed manner. And, functional program, code, and code segments for implementing the above-described method can be easily inferred by programmers in the technical field to which the embodiment belongs.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

Claims (11)

A communication unit for receiving an RRC connection request signal for connection of a Radio Resource Control (RRC) protocol of the terminal from a terminal or a base station; And
A controller for determining whether an Establishment Cause included in the RRC connection request signal is identification information mo-VData indicating Voice over LTE;
/ RTI >
Wherein,
And gives a priority of an LTE bearer connection to a terminal corresponding to the identification information,
Mobility Management Entity (MME). The method according to claim 1,
Wherein,
And shortening a backoff time of the LTE bearer connection for the identification information,
Mobility management entity. The method according to claim 1,
Increasing the backoff time of an LTE bearer connection to a terminal that does not correspond to the identification information when the wireless communication network is in a congested state,
Mobility management entity. The method according to claim 1,
Wherein,
When the wireless communication network is in a congested state, suspends an LTE bearer connection request to a terminal not corresponding to the identification information for a predetermined time,
And transmits a request signal for connection to an LTE bearer to a terminal corresponding to the identification information to an S-GW (Serving Gateway)
Mobility management entity. The method according to claim 1,
Wherein,
When the number of times of reception of the request signal for the LTE bearer connection is equal to or greater than the threshold, it is determined that the wireless communication network is in a congested state,
Mobility management entity. Receiving an RRC connection request signal for a radio resource control (RRC) protocol connection of the UE from a UE or a base station;
Determining whether an Establishment Cause included in the RRC connection request signal is identification information mo-VData indicating Voice over LTE (VoLTE); And
Assigning a priority of an LTE bearer connection to a terminal corresponding to the identification information;
/ RTI >
A method for controlling an LTE bearer connection of a Mobility Management Entity (MME). The method according to claim 6,
The step of granting the priority includes:
Shortening a backoff time of the LTE bearer connection for the identification information;
/ RTI >
A method for controlling an LTE bearer connection of a mobility management entity. The method according to claim 6,
The step of granting the priority includes:
Increasing a backoff time of an LTE bearer connection to a terminal that does not correspond to the identification information when the wireless communication network is in a congested state;
/ RTI >
A method for controlling an LTE bearer connection of a mobility management entity. The method according to claim 6,
The step of granting the priority includes:
When the wireless communication network is in a congested state, interrupting an LTE bearer connection request to a terminal not corresponding to the identification information for a predetermined time;
Transmitting a request signal for connection of an LTE bearer to a terminal corresponding to the identification information to an S-GW (Serving Gateway);
/ RTI >
A method for controlling an LTE bearer connection of a mobility management entity. The method according to claim 6,
Determining that the wireless communication network is in a congested state when the number of times of receipt of the request signal for the LTE bearer connection is equal to or greater than a threshold value;
≪ / RTI >
A method for controlling an LTE bearer connection of a mobility management entity. A computer-readable recording medium storing a program for executing the method according to any one of claims 6 to 10.

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