KR20090131940A - Device, system and method that prevent from data loss during handover - Google Patents

Abstract

PURPOSE: A temporary storing device for preventing data loss during handover, a system thereof, and a method thereof are provided to prevent an End-to-End retry process by retransmitting data stored temporarily therein irrespective of generation of a drop of transmitting data. CONSTITUTION: A first RNS (Radio Network Subsystem)(100) controls a user terminal. A second RNS(200) receives a control right of the user terminal during a first RNS handover. A core network(300) connects a first RNS with a second RNS. A temporary storing device(400) stores temporarily the data to be transmitted from the core network to the first RNS. The temporary storing device transmits the data corresponding to a handover time among the temporarily stored data.

Description

Device, system and method that prevent from data loss during handover

In the case of handover between different Radio Network Subsystems (RNSs), the present invention relates to a technical field for preventing data loss caused by Serving Radio Network Subsystem (SRNS) relocation.

1 shows a WCDMA packet network. 1 includes a Node B 220 for controlling and maintaining a call with a WCDMA mobile communication terminal 210. In addition, the RNC 230 and the WCDMA mobile communication terminal, which provide an optimal path for processing voice and packet data by incorporating an ATM switch and connect with the peripheral device, are connected at the time of connection to the Internet. It includes a Serving GPRS Support Node (SGSN) 310 which is a core node of a GPRS network for transmitting packet data and signals. It also includes a Gateway GPRS Support Node (GGSN) 320 that serves as a gateway for registration with the Internet and provides packet data services through signaling with the HLR.

 In order to transmit a packet using the WCDMA network technology, a packet data protocol (PDP) context is transmitted and received between the RNC 230 and the SGSN / GGSN 310 and 320, and a GTP tunnel is formed using the GTP protocol. The method of transmitting the next packet is used.

Femto refers to a very small unit of 10-15, and Femto Cell refers to an indoor base station for a very small / low power home / office. It is used in the same sense as picocell, but it is being used in a more advanced sense. Femto Cell is a small cellular base station that connects to broadband routers. It connects existing 2G and 3G voice and data to mobile carriers' backbone networks through DSL links.

Femtocell can be a catalyst for promoting 3G penetration and broadening indoor coverage. In other words, the technical enhancement of indoor coverage of technologies such as W-CDMA, HSDPA, and EVDO plays a very important role in service provision. Therefore, routing traffic through IP networks greatly enhances network quality and capacity while moving. OPEX, which carriers are investing in backhaul leased lines, has also been reduced, which is a big advantage from a strategic and economic perspective. In other words, Femto BTS (Base Transceiver Station) has the advantages of increased coverage, reduced infrastructure costs, and accelerated fixed mobile convergence (FMC).

FIG. 2 is a diagram illustrating a configuration of a universal mobile telecommunication system (UMTS) of a general 3GPP network in the related art for providing a mobile communication service to a user equipment (UE) 40. The UMTS includes at least one UTS (UTRAN: UNTS Terrestrial Radio Access Network) 20 including at least one Radio Netwrok Subsystem (RNS) 10, a Gateway MSC (GMSC), a Gateway GPRS Support Node (GGSN), Core Network (CN) 30 including a Serving GPRS Support Node (SGSN), a Mobile Center / Visitor Location Register (MSC / VLR), a Home Location Register (HLR), and the like.

In addition, the RNS 10 is one radio network controller (RNC) 12 that controls a plurality of node Bs 11 and a plurality of node Bs 11. Is done.

In the configuration of the core network (CN) 30, MSC / VLR provides a circuit switched (CS) service, and SGSN provides a packet switched service. GMSC refers to a switch at a point where a UMTS Public Land Mobile Network (PLMN) is connected to an external circuit switched (CS) network, and a GGSN refers to a switch where a UMTS Public Land Mobile Network (PLMN) is connected to an external packet switched (PS) network. A switch at a point.

Node B (11) of the UMTS configuration is managed by the RNC 12, the uplink receives the information sent from the physical layer of the terminal, the downlink of the UTRAN (20) for transmitting data to the terminal ( Access Point) role.

The RNC 12 is in charge of allocating and managing radio resources. The RNC in charge of direct management of the Node B 11 is called a Control RNC (hereinafter referred to as a CRNC), and is in charge of managing a public radio resource. The RNC managing dedicated radio resources allocated to each terminal is called a serving RNC (SRNC). And, the RNS where the CRNC is located is called SRNS.

In FIG. 2, the interface between the mobile communication terminal (UE) 40 and the Node B 11 is Uu, and the interface between the Node B 11 and the RNC 12 is Iub, between the RNC 12 and the RNC 12. Is called Iur, and the interface between the RNC 12 and the CN 30 is referred to as Iu.

If the RNCs of RNS are not connected to the Iur interface, SRNS relocation is involved. If a handover involving SRNS relocation is performed, data loss occurs.

In such a case, problems such as a decrease in total data rate and a decrease in reliability of data due to data loss occur.

In the case of handover with SRNS relocation, a method for temporarily storing data transmitted from the core network to SRNS in a temporary storage device and transferring the temporarily stored data to the handovered RNS when the handover is terminated. It is an object of the present invention to provide.

That is, the first RNS (Radio Network Subsystem) to which the user terminal belongs; A second RNS which is an object to which the user terminal hands over from the first RNS controlling the user terminal to transfer control of the user terminal; A core network to which the first RNS and the second RNS are connected; And a temporary storage device configured to temporarily store data transmitted from the core network to the first RNS and to transmit data corresponding to a time for performing the handover from the temporarily stored data to the second RNS. It is an object of the present invention to provide a wireless network system for preventing handover data loss.

A method for preventing handover data loss according to the first aspect of the present invention for achieving the above object is a wireless network system in which a first RNS (Radio Network Subsystem) and a second RNS are connected to a core network. In the method for preventing handover data loss in the [a] temporary storage device for temporarily storing data transmitted to the first RNS currently controlling a user terminal (UE) in the core network temporarily stores the data. step; [b] performing, by the wireless network system, handing over the user terminal control from the first RNS to the second RNS; [c] the temporary storage device transmitting the data corresponding to the handover execution time among the temporarily stored data to the second RNS.

Preferably, at least one of the first RNS and the second RNS includes at least one user terminal, at least one node-B wirelessly connected to the terminal, and a radio network controller (RNC) for allocating and managing radio resources of the user terminal; A wireless network controller).

Preferably, one of the first RNS and the second RNS may include a femtocell base station connected to the core network and the Internet and a user terminal wirelessly connected to the femtocell base station.

Preferably, the femtocell base station may be wirelessly connected to a user terminal located in the home.

Preferably, the storage period of the temporarily stored data may correspond to the time required to perform the handover.

Preferably, the temporary storage device may transmit the temporarily stored data to RNS corresponding to a Tunnel Endpoint Identifier (TEID) included in the temporarily stored data.

According to a second aspect of the present invention, a temporary storage device for preventing handover data loss controls a first RNS (Radio Network Subsystem) to which a user terminal belongs and the user terminal. At the time of temporarily storing data transmitted to the first RNS in the core network to which the second RNS, which is the object to which the control of the user terminal is transferred, is transmitted from the first RNS, and performs the handover on the temporarily stored data. The corresponding data is transmitted to the second RNS.

Preferably, at least one of the first RNS and the second RNS includes at least one user terminal, at least one node-B wirelessly connected to the terminal, and a radio network controller (RNC) for allocating and managing radio resources of the user terminal. A wireless network controller).

Preferably, one of the first RNS and the second RNS may include a femtocell base station connected to the core network and the Internet and a user terminal wirelessly connected to the femtocell base station.

Preferably, the femtocell base station may be wirelessly connected to a user terminal located in the home.

Preferably, the temporary storage device may transmit the temporarily stored data to RNS corresponding to a Tunnel Endpoint Identifier (TEID) included in the temporarily stored data.

According to a third aspect of the present invention, a wireless network system for preventing handover data loss includes: a first RNS (Radio Network Subsystem) to which a user terminal belongs; A second RNS which is an object to which the user terminal hands over from the first RNS controlling the user terminal and passes control of the user terminal; A core network to which the first RNS and the second RNS are connected; And a temporary storage device configured to temporarily store data transmitted from the core network to the first RNS and to transmit data corresponding to a time for performing the handover from the temporarily stored data to the second RNS. It is done.

Preferably, at least one of the first RNS and the second RNS includes at least one user terminal, at least one node-B wirelessly connected to the terminal, and a radio network controller (RNC) for allocating and managing radio resources of the user terminal; A wireless network controller).

Preferably, one of the first RNS and the second RNS may include a femtocell base station connected to the core network and the Internet and a user terminal wirelessly connected to the femtocell base station.

Preferably, the femtocell base station may be wirelessly connected to a user terminal located in the home.

Preferably, the temporary storage device may transmit the temporarily stored data to RNS corresponding to a Tunnel Endpoint Identifier (TEID) included in the temporarily stored data.

According to the present invention, when handover is performed in a system in which a link between the RNC and the RNC is not configured, data loss that may occur due to SRNS relocation can be prevented, thereby enabling more stable, effective and reliable wireless communication.

In particular, in a system including a femtocell base station, it is possible to prevent possible data loss due to SRNS relocation when the Iur link between the femtocell base station of the femtocell and the RNC of the macro cell is not connected.

That is, due to relocation, even if there is a drop of data in transit, the end-to-end retry procedure can be prevented by preventing the end-to-end retry procedure by immediately retransmitting the data temporarily stored in the temporary storage device.

A method for preventing handover data loss according to the first aspect of the present invention for achieving the above object is a wireless network system in which a first RNS (Radio Network Subsystem) and a second RNS are connected to a core network. In the method for preventing handover data loss in the [a] temporary storage device for temporarily storing data transmitted to the first RNS currently controlling a user terminal (UE) in the core network temporarily stores the data. step; [b] performing, by the wireless network system, handing over the user terminal control from the first RNS to the second RNS; [c] the temporary storage device transmitting the data corresponding to the handover execution time among the temporarily stored data to the second RNS.

According to a second aspect of the present invention, a temporary storage device for preventing handover data loss controls a first RNS (Radio Network Subsystem) to which a user terminal belongs and the user terminal. At the time of temporarily storing data transmitted to the first RNS in the core network to which the second RNS, which is the object to which the control of the user terminal is transferred, is transmitted from the first RNS, and performs the handover on the temporarily stored data. The corresponding data is transmitted to the second RNS.

A wireless network system for preventing handover data loss according to a third aspect of the present invention for achieving the above object comprises: a first RNS (Radio Network Subsystem) to which a user terminal belongs; A second RNS which is an object to which the user terminal hands over from the first RNS controlling the user terminal and passes control of the user terminal; A core network to which the first RNS and the second RNS are connected; And a temporary storage device configured to temporarily store data transmitted from the core network to the first RNS and to transmit data corresponding to a time for performing the handover from the temporarily stored data to the second RNS. It is done.

Specific embodiments of the present invention will be described with reference to the accompanying drawings.

3 illustrates a wireless network system for preventing handover data loss including a temporary storage device according to an embodiment of the present invention.

3 includes user terminals 110 and 210, a first RNS 100, a second RNS 200, a core network 300, and a temporary storage device 400. The user terminal 110 belongs to the coverage of the node-B 120 of the first RNS 100 and moves 210 to the coverage area of the nodeB 220 of the second RNS 200. That is, the user terminal is controlled by the first RNS and hands over to be controlled by the second RNS 200. 3, there is no Iur link between the RNC 130 of the first RNS and the RNC 230 of the second RNS 200. Therefore, Iur handover cannot be performed and handover must be performed while performing SRNS relocation. In this case, the terminal cannot receive data received in the first RNS from the core network during handover. Unreceivable data is a loss of data, causing poor call quality.

Therefore, a temporary storage device 400 that serves as a buffer for temporarily storing data transmitted from the core network to the first RNS is required. The temporary storage device 400 transmits data that could not be transmitted to the first RNS during the handover to the second RNS after the handover is terminated.

The storage period of the data temporarily stored by the temporary storage device may correspond to a time required to perform the handover. That is, the temporary storage device preferably stores all data transmitted from the core network to the SRNS for at least the time required for handover.

The temporary storage device may transmit the temporarily stored data to an RNS corresponding to a Tunnel Endpoint Identifier (TEID) included in the temporarily stored data.

4 illustrates a case where the first RNS is a femtocell base station as an embodiment of the present invention. 4 includes user terminals 210 and 110, nodeB 220, RNC 230, femtocell base station 140, core network 300, and temporary storage device 400. The femtocell base station is a femtocell base station of a type that is separated from the core network and does not include the functions of the core network. The femtocell base station 140 is connected to the core network through the Internet IP network. The femtocell base station 140 typically has a small coverage area by wirelessly connecting to a terminal in the home. The femtocell base station corresponds to one RNS and node b by itself. In FIG. 4, the user terminal 110 under the control of the femtocell base station hands over to the second RNS.

Since there is no Iur link between the femtocell base station and the RNC 230, a handover with SRNS relocation is required. In this case, data loss is inevitable. Therefore, data transmitted from the core network to the femtocell base station is temporarily stored in the temporary storage device. That is, the communication data transmitted from the core network to the femtocell base station is stored in the temporary storage device, which corresponds to a period from when the handover with SRNS relocation starts until the handover ends. When the handover is completed, the second RNS can receive the data from the temporary storage device that was not received during the handover.

Meanwhile, the destination of each data can be known using a Tunnel Endpoint IDentifier (TEID) in a Serving GPRS support node (SGSN), which is one of the nodes of the core network. That is, the data is transmitted to the RNS with reference to the TEID.

Figure 5 briefly shows the configuration of the temporary storage device.

The temporary storage device includes a storage unit 401, a control unit 402, and a communication unit 403. The controller receives data transmitted from the core network to the femtocell base station through the communication unit and stores the data in the storage unit.

The method for preventing handover data loss according to the present invention is a method for preventing handover data loss in a wireless network system in which a first RNS (Radio Network Subsystem) and a second RNS are connected to a core network. and temporarily storing the data by a temporary storage device that temporarily stores data transmitted to the first RNS currently controlling a user terminal (UE) in the core network; [b] performing, by the wireless network system, handing over the user terminal control from the first RNS to the second RNS; [c] the temporary storage device transmitting the data corresponding to the handover execution time among the temporarily stored data to the second RNS.

Therefore, in the case of handover with SRNS relocation, data loss that can occur due to SRNS relocation can be prevented, thereby enabling more stable, effective and reliable wireless communication.

1 is a schematic diagram of a WCDMA system.

2 shows a schematic diagram of a UMTS network.

Figure 3 shows the application concept of the present invention in handover.

Figure 4 shows the application concept of the present invention in the handover from the femtocell to the macro cell.

5 is a block diagram of a temporary storage device according to the present invention.

<Description of main parts of drawing>

100: first RNS

110: user equipment

120: Node B

130: SRNC (Serving Radio Network Controller; RNC controlling terminal)

140: femtocell base station 200: second RNS

210: user equipment 220: Node B

230: RNC (Radio Network Controller) 300: core network

400: temporary storage device 401: storage unit

402: control unit 403: communication unit

Claims (16)

A method for preventing handover data loss in a wireless network system in which a first RNS (Radio Network Subsystem) and a second RNS are connected to a core network, [a] temporarily storing the data by a temporary storage device for temporarily storing data transmitted to the first RNS currently controlling a user terminal (UE) in the core network; [b] performing, by the wireless network system, handing over the user terminal control from the first RNS to the second RNS; [c] the temporary storage device transmitting the data corresponding to the handover execution time among the temporarily stored data to the second RNS to prevent handover data loss in a wireless network system. Way. The method of claim 1, One of the first RNS and the second RNS includes one or more node-Bs wirelessly connected to the user terminal and a Radio Network Controller (RNC) for allocating and managing radio resources of the user terminal. The method for preventing handover data loss, characterized in that. The method of claim 1, Any one of the first RNS and the second RNS includes a femtocell base station connected to the core network and the Internet and the femtocell base station is wirelessly connected to the user terminal. The method of claim 3, The femtocell base station is a method for preventing handover data loss, characterized in that the wireless connection with the user terminal located in the home. The method of claim 1, And a storage period of the temporarily stored data corresponds to a time required to perform the handover. The method of claim 1, And the temporary storage device transmits the temporarily stored data to an RNS corresponding to a Tunnel Endpoint Identifier (TEID) included in the temporarily stored data. A first RNS (Radio Network Subsystem) controlling a user terminal and a second RNS which is an object to which control of the user terminal is transferred from the first RNS are transmitted to the first RNS. And temporarily storing the data to be transmitted and transmitting data corresponding to the time for performing the handover among the temporarily stored data to the second RNS. The method of claim 7, wherein One of the first RNS and the second RNS includes at least one node-B wirelessly connected to the user terminal and a Radio Network Controller (RNC) for allocating and managing radio resources of the user terminal. Temporary storage device to prevent handover data loss. The method of claim 7, wherein Any one of the first RNS and the second RNS includes a femtocell base station connected to the core network and the Internet, wherein the femtocell base station is wirelessly connected to the user terminal characterized in that the temporary storage device for preventing handover data loss . The method of claim 7, wherein The femtocell base station is a temporary storage device for preventing handover data loss, characterized in that the wireless connection with the user terminal located in the home. The method of claim 7, wherein The temporary storage device transmits the temporarily stored data to an RNS corresponding to a Tunnel Endpoint Identifier (TEID) included in the temporarily stored data. The temporary storage device prevents handover data loss. Device. A first RNS (Radio Network Subsystem) controlling a user terminal; A second RNS which is an object to which the user hands over at the first RNS and hands over control of the user terminal; A core network to which the first RNS and the second RNS are connected; And And a temporary storage device configured to temporarily store data transmitted from the core network to the first RNS and to transmit data corresponding to the time for performing the handover from the temporarily stored data to the second RNS. Wireless network system to prevent handover data loss. The method of claim 12, One of the first RNS and the second RNS includes at least one node-B wirelessly connected to the user terminal and a Radio Network Controller (RNC) for allocating and managing radio resources of the user terminal. A wireless network system for preventing handover data loss. The method of claim 12, Any one of the first RNS and the second RNS includes a femtocell base station connected to the core network and the Internet, wherein the femtocell base station is wirelessly connected to the user terminal. The method of claim 12, The femtocell base station is a wireless network system for preventing a handover data loss, characterized in that the wireless connection with the user terminal located in the home. The method of claim 12, The temporary storage device transmits the temporarily stored data to an RNS corresponding to a TEID (Tunnel Endpoint Identifier) included in the temporarily stored data, the wireless network preventing handover data loss. system.

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