KR20090045778A - Data transmission method and system for reducing the load of the mobility management unit in a mobile communication network that generates uplink bearer and down bearer asynchronously - Google Patents

Abstract

According to the present invention, when an unexpected delay occurs in the setup of an uplink bearer and a downlink bearer in a system for asynchronously creating an uplink bearer and a downlink bearer, unnecessary calls are made to the bearer management entity by data traffic received before the bearer setup. A method and apparatus for preventing a request from being forwarded. In the first embodiment, the bearer management entity informs the gateway carrying the data traffic of the bearer creation state so that the gateway manages the data traffic. In the second embodiment, the bearer preparation status is notified to the radio access network, and the radio access network is not ready until the bearer is ready. This does not cause upstream data traffic.

EPS, MME, Asynchronous UL / DL establishment

Description

TECHNICAL AND METHOD FOR DELIVERING DATA WHILE REDUCING LOAD OF MME IN MOBILE TELECOMMUNICATION NETWORK WHERE UPLINK AND DOWNLINK BEARERS ESTABLISH ASYNCHRONOUSLY}

The present invention relates to a communication system according to the Internet Protocol (IP), and in particular, when a terminal is changed from an idle state to an active state, a bearer in a system that asynchronously performs up / down bearer configuration. A system and method for reducing call requests that can be passed unnecessarily to a management unit.

FIG. 1 is a diagram illustrating an Evolved Packet System (EPS) architecture, which is an evolved packet system underway in the 3rd Generation Partnership Project (3GPP).

Referring to Figure 1, EPS is E-UTRAN (Evolved Universal Mobile Telecommunication Service (UMTS) Terrestrial Radio Access Network (RAN)) 103, E-UTRAN (Mobility Management Entity: hereinafter referred to as "MME") ( 113), a serving gateway (hereinafter referred to as "SGW") 105, and a packet or public data network (PDN) gateway (hereinafter referred to as "PGW") 107 have.

The E-UTRAN 103 is an evolved access network wirelessly connected to a UE (User Equipment: "UE") 101 using the EPS, evolved Node B: " eNB ”(not shown) is included as an E-UTRAN entity. In this specification, the eNB and the E-UTRAN are treated the same. The MME 113 performs NAS (Non Access Stratum) signaling, NAS signaling security, mobility management between 3GPP networks, location-related functions of an idle mode UE, and roaming. Function, authentication, bearer management, etc. are performed. The SGW 105 provides mobility management between eNBs, mobility management between 3GPP networks, idle mode downlink packet buffering, legal interception, packet routing and packet routing of E-UTRAN idle mode downlink. and forwarding). The PGW 107 also includes policy enforcement, per-user based packet filtering, charging support, lawful interception, and UE IP allocation. , Packet screening, and the like.

The Policy Control and Charging Rules Function (PCRF) 111 manages a policy, a quality of service (QoS), etc. to be applied to the terminal 101. The Serving GPRS Support Node (SGSN) 115 is an entity related to a legacy packet network (e.g., General Packet Radio Services (GPRS) RAN or GERAN (Global System for Mobile Communications (GSM) Edge RAN). The home subscriber server (HSS) 116 manages user subscription information and location information. The entities may have additional functionality not mentioned.

FIG. 2 is a diagram illustrating a signal procedure illustrating an operation of a service request for a terminal in idle state to transmit data in a typical EPS.

The UE 101 in idle state not establishing a wireless connection with the EPS sends a Service Request message to the MME 113 through NAS signaling in step 201 to transmit data. The MME 113 checks bearer information that is being serviced before the UE 101 is in a dormant state, and in step 202, the MME 113 generates an Initial Context Setup Request message, which is a command for generating a radio bearer corresponding to the bearer information, by using SGW ( And transmits the information to the eNB 102 together with uplink bearer (between eNB and SGW) information configured at 105. The uplink bearer information includes an address of the SGW 105 and a GPRS Tunnel Protocol (GTP) TEID (Tunnel Endpoint ID). In step 203, the eNB 102 generates a radio bearer with the UE 101 according to the uplink bearer information. When the step 203 is completed, the uplink bearer configuration of the network direction is completed in the terminal 101, the UE 101 can transmit data to the network in step 204.

In order to deliver down bearer (between eNB and SGW) information to the SGW 105, the eNB 102 transmits an Initial Context Setup Response message including the down bearer information generated in step 203 to the MME 113 in step 205. . The down bearer information includes the address of the eNB and the GTP TEID. In step 206, the MME 113 transmits downlink bearer information to the SGW 105 through an Update Bearer Request message, and receives an Update Bearer Response message from the SGW 105 in step 207. After the step 206, the down bearer setup is completed, and as shown in step 208, it is possible to transfer data to the UE (101).

In a typical EPS operating as described above, due to load conditions, the MME 113 fails to process the Initial Context Setup Response message received in step 205 in a timely manner, and thus, the downlink is directed toward the UE 101 before transmitting an Update Bearer Request message. The packet may be received at the SGW 105. In this case, the SGW 105 determines that the UE 101 is still in a dormant state, and unnecessarily sends a request message to the MME 113 to call the UE 101.

The present invention provides a method and system for preventing an unnecessary increase in signaling delivered to a mobility management entity having a bearer management function due to an asynchronous bearer creation procedure in a system for asynchronously generating up and down bearers. .

The present invention provides a method and system for optimizing the signaling delivered to a bearer management unit in an asynchronous bearer creation procedure.

In a preferred embodiment of the present invention, a data transmission method in a system for asynchronously generating an uplink bearer and a downlink bearer,

Receiving a service request indication including an identifier of the first terminal and bearer information, and when receiving downlink data transmitted from the second terminal, storing the downlink data according to the service request indication, and downlink bearer information And waiting to receive the message, and when receiving the message including the down bearer information, transmitting the stored downlink data to the first terminal through a down bearer set by the down bearer information. It features.

The method according to the first embodiment of the present invention, in the mobile communication system for generating the up and down bearer asynchronously, in the case of EPS, the up bearer at the same time as the start of the up bearer creation procedure in the MME 113 The SGW 105 informing the SGW 105 that the down bearer generation is to be continued, and the SGW 105 acknowledging the uplink data generation procedure does not transmit the uplink data from the UE 101 to the PGW 107 for a predetermined time. Buffering to prevent receiving downlink data to be triggered by uplink data, or when receiving the downlink data by the SGW 105 aware of the uplink data generation procedure, without making a call request to the MME 113, eNB And buffering for a certain period of time without forwarding to 102 to prevent unnecessary call requests from being delivered to the MME 113.

According to the second embodiment of the present invention, the eNB 102 does not enforce uplink data transmission scheduling to the UE 101 so that the UE 101 does not send uplink data after generating the uplink bearer, and then the MME 113. Starting the uplink data transmission scheduling after receiving an explicit instruction from the UE, and receiving uplink data from the UE 101.

The system according to the embodiment of the present invention is a communication system for providing a packet-based mobile communication service supporting the idle mode and a terminal using the same, and when a packet service is requested from the terminal in the idle state, From a radio access network (E-UTRAN, eNB) for creating and managing a bearer, a mobility management unit (MME) for requesting a radio bearer creation to the radio access network, and managing generation of up and down bearers, and a mobility management unit (MME) SGW and PGW for receiving the bearer information, and forwards the data packet between the terminal and the packet data network (PDN).

According to the present invention, in a mobile communication system in which an uplink bearer and a downlink bearer are asynchronously generated, unnecessary terminal calls transmitted to a bearer management unit managing bearer generation can be reduced, thereby increasing the operation efficiency of the bearer management unit. There is this.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

An important aspect of the present invention is that, when generating up and down bearers asynchronously in a communication system, the bearer manager notifies the core network node or the access network node of the bearer generation process, and an unnecessary terminal call request or bearer creation request is added in the bearer generation process. To prevent it from happening.

Given that most of the packet networks use the IP protocol and the Internet, such as the World Wide Web, is the most popular packet service, when the UE requests to establish a radio bearer and transmits uplink data, after the UE establishes the radio bearer In most cases, the first data packet includes a DNS (Domain Name Service) request. In general, since the DNS server is located in the operator's network, a response to a DNS request occurs very quickly, and thus a DNS response directed to a terminal may be frequently received during the creation of a down bearer. Similarly, it can be applied to other cases of providing packet service rather than DNS service.

3 is a diagram illustrating signaling of an operation of buffering uplink data until a downlink bearer is generated by an MME 113 having a bearer management function informing a gateway of bearer creation according to a first embodiment of the present invention.

Referring to FIG. 3, the UE 101 in idle state that does not establish a wireless connection with the EPS sends a Service Request message to the MME 113 in step 301 to transmit data. The MME 113 checks the bearer information that was being serviced before the UE 101 is in the dormant state, and in step 302, the MME 113 sends a Service Request Indication message to inform the SGW 105 that a bearer creation request is in progress. Send to The Service Request Indication message includes a terminal identifier such as an International Mobile Station Identifier (IMSI) and bearer information on a radio bearer to be activated. If the Service Request Indication message is not transmitted, the SGW 105 operates according to the existing technology of FIG. 2.

In step 303, the MME 113 transmits an Initial Context Setup Request message, which is a command for generating the radio bearer, to the eNB 102 along with uplink bearer (between eNB and SGW) information set in the SGW 105. The uplink bearer information includes an address of the SGW 105 and a GTP TEID associated with the radio bearer. In step 304, the eNB 102 generates a radio bearer with the UE 101 according to the radio bearer information. The radio bearer is connected to a radio bearer between the UE 101 and the eNB and an EPS bearer (that is, a GTP tunnel) connecting the eNB to the SGW / PGW. In this case, downlink bearer information is generated for the downlink bearer between 102) associated with the radio bearer and the SGW, and the downlink bearer information includes an eNB address and a GTP TEID. When the step 304 is completed and the radio bearer is generated, the uplink bearer setup in the network direction is completed in the terminal 101, the UE 101 can transmit the uplink data to the network in step 305. At this time, in order to prevent the uplink data transmitted by the UE 101 from being transmitted to a network server such as a DNS server, and generating downlink data, which is a response thereto, the SGW 105 receiving the Service Request Indication in step 302 is connected to the UE ( And buffers the upstream data associated with 101).

In order to deliver down bearer (between eNB and SGW) information to the SGW 105, the eNB 102 transmits an Initial Context Setup Response message including the down bearer information generated in step 304 to the MME 113 in step 306. . The downlink bearer information includes an ENB address and a GTP TEID. In step 307, the MME 113 delivers the downlink bearer information in an Update Bearer Request message to the SGW 105. Since the SGW 105 confirms that the down bearer has been set up based on the down bearer information, the SGW 105 transmits the uplink data which has been buffered to the PGW 107 in step 308. At the same time, in step 309, the SGW 105 sends an Update Bearer Response message to the MME 113. The downlink data, which is a response to the uplink data delivered in step 308, is delivered to the UE 101 in step 310.

4 is a diagram illustrating signaling of an operation of buffering downlink data until a downlink bearer is generated by an MME 113 having a bearer management function informing a gateway of bearer creation according to a first embodiment of the present invention.

Referring to FIG. 4, the UE 101 in idle state that does not establish a wireless connection with the EPS sends a Service Request message to the MME 113 in step 401 to transmit data. The MME 113 checks bearer information on the radio bearer that was being serviced before the UE 101 is in the dormant state, and in step 402, the MME 113 sends a Service Request Indication message to inform the SGW 105 that bearer generation is in progress. Send to 105. The Service Request Indication message includes a terminal identifier such as IMSI and bearer information on a radio bearer to be activated. If the Service Request Indication message is not transmitted, the SGW 105 operates as in the conventional technology.

In step 403, the MME 113 transmits an Initial Context Setup Request message, which is a command for generating the radio bearer, to the eNB 102 along with uplink bearer (between eNB and SGW) information set in the SGW 105. The uplink bearer information includes an address of the SGW 105 and a GTP TEID associated with the radio bearer. In step 404, the eNB 102 generates a radio bearer with the UE 101 according to the radio bearer information. In this case, downlink bearer information about a downlink bearer between the eNB 102 and the SGW is generated. When the uplink bearer setup in the network direction is completed in the terminal 101, the UE 101 may transmit uplink data to the network in step 405.

Downlink data due to the response to the uplink data or for other reasons is received by the SGW 105 in step 407. In this case, the downlink data may be received by the SGW 105 before step 408 in which downlink bearer information is transmitted to the SGW 105. In this case, the SGW 105, which does not yet have downlink bearer information, buffers the downlink data without transmitting it to the eNB 102, and waits for reception of the downlink bearer information. Since the SGW 105 is informed that it is generating a bearer with the UE 101 from the MME 113 in step 402, the SGW 105 does not make an unnecessary call request to the UE 101 to the MME 113.

In order to deliver down bearer (between eNB and SGW) information to the SGW 105 immediately after step 404, the eNB 102 transmits an Initial Context Setup Response message including the down bearer information generated in step 404 to the MME 113. To). The down bearer information includes the address of the eNB and the GTP TEID. In step 408, the MME 113 transmits the down bearer information to the SGW 105. Since the SGW 105 confirms that the down bearer is set up based on the down bearer information, the SGW 105 transmits the downlink data that has been buffered to the eNB 102 in step 409. At the same time, in step 410, the SGW 105 sends an Update Bearer Response message to the MME 113. The order of steps 409 and 410 may be changed from that shown.

5 is a diagram illustrating an operation in which an MME 113 having a bearer management function informs an eNB of an access network of a bearer creation process and waits for scheduling of uplink data until a downlink bearer is generated according to the second embodiment of the present invention. A diagram illustrating signaling.

Referring to FIG. 5, the UE 101 in idle state that does not establish a wireless connection with the EPS sends a Service Request message to the MME 113 in step 501 to transmit data. The MME 113 checks bearer information on the radio bearer that was being serviced before the UE 101 is in the dormant state, and in step 502, the MME 113 sends an Initial Context Setup Request message, which is a command for generating the radio bearer, to the SGW 105. It transmits to the eNB 102 along with uplink bearer (between eNB and SGW) information set in FIG. The uplink bearer information includes an address of the SGW 105 and a GTP TEID associated with the radio bearer.

In step 503, the eNB 102 generates an uplink radio bearer with the UE 101 according to the radio bearer information. In this case, downlink bearer information about a downlink bearer between the eNB 102 and the SGW is generated. If necessary, in step 502, information that explicitly specifies whether to immediately allow scheduling of uplink data for each bearer is transmitted together with QoS information of the bearer. Although the setup of the radio bearer between the terminal 101 and the eNB 102 and the uplink bearer between the eNB 102 and the SGW 105 in the network direction from the terminal 101 are completed, in step 504, the eNB 102 moves upward. The UE 101 does not send uplink data because it does not immediately start scheduling radio bearers. That is, the eNB 102 waits without scheduling an uplink radio bearer for the UE 101 until it is notified that the setup of the downlink bearer is completed from the MME 113.

In order to deliver down bearer (between eNB and SGW) information to the SGW 105 immediately after step 503, the eNB 102 transmits an Initial Context Setup Response message including the down bearer information generated in step 503 to the MME 113. To). The down bearer information includes the address of the eNB 102 and the GTP TEID. In step 506, the MME 113 carries the down bearer information in an Update Bearer Request message to the SGW 105, and in step 507, the SGW 105 sends an Update Bearer Response message to the MME 113.

Upon receiving the Update Bearer Response message, the MME 113 sends an Uplink Allowed message indicating that the downlink bearer setup is completed to the eNB 102 in step 508. The Uplink Allowed message includes an identifier for distinguishing the terminal 101 and a list of uplink radio bearers to allow scheduling. If the scheduling of all radio bearers is allowed, the list of uplink radio bearers may be omitted. The step 508 may be performed immediately after the step 506 and before the step 507. Upon being informed that the setup of the downlink bearer is completed, the eNB 102 performs scheduling of the uplink radio bearer in step 509. According to the scheduling of the uplink radio bearer, the UE 101 can transmit uplink data and receive downlink data in steps 510 and 511.

1 illustrates a 3GPP EPS architecture.

2 is a signal procedure illustrating an operation of making a service request for a terminal in idle state to transmit data in a typical EPS.

3 illustrates signaling of an operation of buffering uplink data until a downlink bearer is created according to a first embodiment of the present invention.

4 illustrates signaling of an operation of buffering downlink data until a downlink bearer is created according to a first embodiment of the present invention.

5 illustrates signaling of an operation of waiting for scheduling of uplink data until a downlink bearer is created according to a second embodiment of the present invention.

Claims (1)

A data transmission method in a system for generating an uplink bearer and a downlink bearer asynchronously, Receiving a service request indication including an identifier of the first terminal and bearer information; Receiving downlink data transmitted from a second terminal, storing the downlink data according to the service request indication, and waiting for reception of downlink bearer information; And when the message including the down bearer information is received, transmitting the stored downlink data to the first terminal through a down bearer set by the down bearer information.

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