KR20090121593A - Method and apparatus for preventing disconnection at the boundary between rncs - Google Patents

Abstract

PURPOSE: A method and an apparatus for preventing call disconnection at the boundary between base station controllers are provided to enable a terminal to delay a call disconnection procedure even though a message transceived with a base station controller is abnormal, thereby preventing call disconnection. CONSTITUTION: A message receiving unit(210) receives a message of informing conversion from the first base station controller to the second base station controller during handover from the first base station controller to the second base station controller. A message transmitting unit(220) transmits an acknowledgement message about the received message to the second base station controller. When the acknowledgement message is transmitted, a timer(240) is driven during a fixed time. A controller(230) performs a converting procedure between the first and second base station controllers according to whether a response message about the acknowledgement message is received until the timer expires.

Description

Method and apparatus for preventing disconnection at the boundary point between base station controllers {Method and apparatus for preventing disconnection at the boundary between RNCs}

The present invention relates to a method and apparatus for preventing call truncation at a boundary point between base station controllers. A method and apparatus for preventing call truncation at a boundary point between base station controllers that can be prevented.

With the rapid development of computer, electronic and communication technologies, various wireless communication services using wireless networks have been provided. In order to provide such a service, a mobile communication system has been developed through a first generation analog AMPS (Advanced Mobile Phone Systems) method and a second generation cellular (PCS) / personal communication service (PCS) method. Recently, IMT-2000 (International Mobile Telecommunication-2000), a third generation high speed data communication, has been used. IMT-2000 was developed for personal mobility guarantee and high-speed data transmission to ensure mobility between countries by integrating systems of countries using different wireless access standards. It is synchronous with Code Division Multiple Access (CDMA) 2000. It was developed separately from Wideband Code Division Multiple Access (WCDMA).

In the WCDMA scheme, when a terminal moves between base station controllers, and there is no direct connection (Iur) between the base station controllers, a Serving RNS (Reloaction) process is performed. In this process, the base station controller is moved from the base station controller to which the terminal is to be moved. When receiving a message indicating the switch of the terminal, the terminal transmits a confirmation message for the received message to the base station controller to move.

In addition, the base station controller to which the terminal is to move transmits a response message to the terminal in response to the acknowledgment message transmitted from the terminal, thereby completing the procedure for moving the base station control period of the terminal. At this time, the validity of the message exchanged between the terminal and the base station control period is determined through the sequence number included in the mutual message.

However, if the terminal transmits a confirmation message to the base station controller to move to, and then receives a reset message without receiving a response message or receives a message with an invalid sequence number, the operation of the terminal is defined in the current 3GPP standard. Because it is not, arc cutting occurs.

Therefore, there is a need for a method for preventing call truncation that occurs when a terminal receives a reset message or a message having an invalid sequence number when the base station moves the control period.

The present invention has been made in view of the above problems, and when the terminal is handed over in a base station control period, even if a message transmitted and received with the base station controller to which the terminal is moving is abnormal, the call disconnection procedure is delayed for a predetermined time. It is an object of the present invention to provide a method and apparatus for preventing call truncation at a boundary point between base station controllers that prevent truncation.

The object of the present invention is not limited to the above-mentioned object, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a method for preventing call truncation at a boundary point between a base station controller according to an embodiment of the present invention may include: a second base station controller upon handover from a first base station controller to a second base station controller; Receiving a message informing of the switch of the base station controller from the controller, transmitting a confirmation message for the received message to the second base station controller, and when the confirmation message is transmitted, the timer is driven for a predetermined time. Waiting to receive a response message to the confirmation message until it expires.

The apparatus for preventing call disconnection at the boundary point between the base station controller according to an embodiment of the present invention for achieving the above object, when the handover from the first base station controller to the second base station controller, from the second base station controller A message receiver for receiving a message informing of a switch of a base station controller, a message transmitter for transmitting a confirmation message for the received message to the second base station controller, a timer which is driven for a predetermined time during the transmission of the confirmation message, and the timer And a controller for performing a switching procedure between the base station controllers according to whether or not to receive a response message to the confirmation message until it expires.

Method and apparatus for preventing call disconnection at the boundary point between the base station controller according to an embodiment of the present invention has the following effects.

When the terminal handovers the base station control period, there is an effect that a stable handover can be made by adding a message processing procedure that is not defined in the 3GPP standard.

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

Specific details of other embodiments are included in the detailed description and the drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a UMTS communication network according to an embodiment of the present invention.

UMTS communication network 100 according to an embodiment of the present invention is a terminal (User Equipment, hereinafter referred to as "UE") 110, a radio access network (UMTS Terrestrial RAN, hereinafter referred to as "UTRAN") 120 and one or more It may include a Core Network (hereinafter referred to as "CN") 130 connected to the UTRAN 120 including a Radio Network Subsytem (RNS) and responding to a connection with the external network 140.

The UE 110 may include personal digital assistants (PDAs), computers, and the like having wireless communication functions as well as devices used for wireless communication. The UE 10 may be fixed or mobile, and may be called terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a wireless device, and the like, but is not limited thereto.

The UTRAN 120 includes one or more RNS, each RNS is a base station controller (Radio Network Controller) for controlling a plurality of base stations 122 and base stations 122 to which the radio access standard of the 3GPP standard applied to support WCDMA (Hereinafter referred to as "RNC") 124. The UTRAN 120 transmits a call request signal or the like from the UE 110 to the CN 130.

The base station 122 establishes a radio physical channel required for data exchange with the UE 110 according to the control information transmitted from the RNC 124, and transmits data transmitted from the upper layer protocol to the UE 110 according to a wireless environment. do. Along with this, data received from the UE 110 is transferred to an upper layer protocol of the RNC 124. The base station 122 supports various radio access technologies such as channel coding, interleaving, modulation, and demodulation for data transmission in a wireless section. The base station 122 generally refers to a fixed station that communicates with the UE 110 and includes terms such as node-B, base transceiver system (BTS), and access point. It may be called, but is not limited thereto.

The RNC 124 dynamically allocates radio resources of the wireless communication system and controls the base station 122. The RNC 124 manages wired and wireless channels, protocol matching of the mobile communication UE 110, and protocol matching of the base station. Soft Handoff processing, protocol matching with CN 130, General Packet Radio Service (GPRS) access, fault management, system loading (Loading) and the like. The RNC 124 serves as an access point for services provided through the CN 130. In addition, a resource for managing a dedicated radio resource allocated to each UE is called a SRNS (Serving RNS).

A mobile switching center (hereinafter referred to as "MSC" 131a) transmits a signal received or transmitted by the base station 122, and exchanges between mobile communication subscribers, mobile network subscribers and fixed network subscribers such as PSTN and ISDN. The MSC 131a processes basic and additional services, processes an incoming signal of the mobile communication UE 110 in association with an existing network or another network, and processes location registration and handoff.

Circuit switching gateway (Gateway MSC, hereinafter referred to as "GMSC") (131b) is a gateway (Gateway) at the point that is connected to the external network 140 through the MSC (131a). All circuit switched connections are made via GMSC 131b.

It may be referred to as a circuit switching unit 131 including the MSC 131a and the GMSC 131b, and the circuit switching unit 131 establishes a communication path with the UE 110 through the circuit switching connection.

A packet switching support node (Serving GPRS Support Node, hereinafter referred to as "SGSN") 132a is a session for handling mobility management, origination / reception signal processing, and packet data transmission / reception of the UE 110 for GPRS service. (Sess i on) Supports management, authentication and billing functions. It also has a routing processing function of packet data.

A packet switching gateway (Gateway GPRS Support Node, hereinafter referred to as "GGSN") 132b is a serving node of an IP (Internet Protocol) based packet network that provides a high speed packet data service for GPRS data service. It manages session for packet data service, performs routing processing of packet data, and provides interface for connecting WDCMA network and Internet network.

The packet switch 132 may be referred to as the SGSN 132a and the GGSN 132b. The packet exchange unit 132 transmits and receives data in a packet unit in transmitting and receiving data of the UE 110.

The external network 140 is a network connected to the outside through the circuit switching unit 131 or the packet switching unit 132. The circuit switching unit 131 is related to transmission and reception of circuits such as voice calls. The circuit switching unit 131 may be a public switched telephone network (PSTN), an integrated services digital network (ISDN), or a public land mobile network (PLMN). The packet exchange unit 132 is related to the transmission and reception of packets. The packet exchange unit 132 may be an Internet Protocol (IP) network such as the Internet.

The home location register (HLR) 133 stores and manages the location information of the subscriber, and the authentication center (AuC) generates an authentication vector and performs a subscriber authentication function. In general, the authentication center (AuC) is interlocked with the HLR 133 and they can exchange information with each other.

The Equipment Identity Register (hereinafter referred to as "EIR") 134 checks or manages identification information related to hardware of the UE 110. The EIR 134 stores stolen and lost terminal information. The EIR 134 compares terminal information received from the MSC 131a with pre-stored terminal information when requesting subscriber authentication and location registration. You can decide whether or not. To this end, the EIR 134 stores the information of the stolen and lost terminals in a black list.

2 is a block diagram illustrating an apparatus for preventing call truncation at a boundary point between base station controllers according to an embodiment of the present invention. Although not shown in FIG. 2, the same reference numerals will be used for the same elements as those of FIG. 1. In addition, the apparatus 200 for preventing call truncation at the boundary point between the base station controller according to an embodiment of the present invention, during the SRNS handover between the UE 110, during the SRNS relocation procedure For example, it may be understood to prevent call truncation that occurs when receiving a Radio Link Control (RLC) reset message or a message having an invalid sequence number while the SRNS relocation procedure is not completed. Of course, in one embodiment of the present invention has been described a case of receiving a reset message or a message of an invalid sequence number, for example, but this is only an example for the understanding of the present invention is not limited thereto.

The UE 110 and the UTRAN 120 each have a radio protocol layer for managing data transmission in a radio section, and the radio protocol layer includes a PHY layer as a first layer and a medium access protocol (MAC) layer as a second layer. , An RLC layer, a broadcast / multicast control layer, and a radio resource control (RRC) layer, which is a third layer. The PHY layer, which is the first layer, serves to transmit data to a wireless section using various wireless transmission technologies. The second layer, the MAC layer, serves to map various logical channels to various transport channels, and the RLC layer guarantees quality of service (QoS) of each radio bearer (hereinafter referred to as "RB") and QoS. It is in charge of data transmission. The third layer, the RRC layer, controls parameters of the first layer and the second layer in connection with setting, resetting, and releasing the RBs, and is responsible for controlling logical channels, transport channels, and physical channels. At this time, in one embodiment of the present invention has been described for the case where there is a radio protocol layer in the UE 110 and UTRAN 120, for example, the present invention relates to the SRNS relocation procedure, so that the radio protocol layer is RNC It can be understood to exist at (124).

In this case, the message processing between the UE 110 and the RNC 124 is in charge of the RLC layer and the RRC layer, respectively, and the RLC layer checks the validity of the message based on the sequence number included in the mutual message. In addition, in one embodiment of the present invention, it can be understood that RLC reset means sequence number reset of a message, and RRC reset means call truncation.

As shown in FIG. 2, the apparatus 200 for preventing call truncation at the boundary point between the base station controllers according to an embodiment of the present invention may switch from a new RNC to a new RNC when an RNC handover of the UE 110 occurs. Message receiving unit 210 for receiving a UMI (UTRAN Mobility Information) message for notifying, a message transmitting unit 220 for transmitting a confirmation message (UMI Confirm message, hereinafter referred to as "UMIC message") for the received UMI message, transmitted The controller 230 may perform a handover procedure of the UE 110 according to whether the response message to the UMIC message is received, and a timer 240 that is driven for a predetermined time from the time when the UMIC message is transmitted.

At this time, in an embodiment of the present invention will be described for example the case where the device 200 for the call disconnection prevention at the boundary point between the base station controller is included in the UE 110, the message from the RNC (124) If a RLC reset message is received from the RNC 124 or a message of an invalid sequence number is received before the response message for the UMIC message transmitted by the transmitter 220 is received, call disconnection occurs at the UE 110. Can be prevented.

The message receiving unit 210 may receive an UMI message informing that the UE 110 transitions to a new RNC from an RNC (hereinafter referred to as "new RNC") that the UE 110 intends to move upon handover by performing an SRNS relocation procedure. The transmitter 220 may transmit a UMIC message for the received UMI message to the RNC 124. In addition, the control unit 230 may perform a process of resetting the sequence number of the message in order to exchange the message with the new RNC before the UMIC message is transmitted from the message transmitter 220.

In an embodiment of the present invention, a case in which the message receiver 210 may receive not only a UMI message but also a response message to the UMIC message transmitted by the message transmitter 220 will be described as an example. In this case, when the message receiver 210 normally receives the response message for the UMIC message, the controller 230 may complete the SRNS relocation procedure normally.

On the other hand, when the RLC reset message is received in the state in which the message receiver 210 does not receive the response message for the UMIC message, or when the response message is received but the sequence number of the message is invalid, call disconnection may occur in the UE 110. In an embodiment of the present invention, since the control unit 230 may operate the timer 240 for a predetermined time from the time when the UMIC message is transmitted, the control unit 230 may perform the RLC during the time that the timer 240 is driven. Even if a reset message is received, the call truncation procedure is not performed. In this case, the time “T” at which the timer 130 is driven may be specified in the UE 110 manufacturing process or may be assigned to the user, but is not limited thereto.

Therefore, the controller 230 ignores the RLC reset message or the message having the invalid sequence number before the time “T” has passed to the message receiving unit 210, and thereafter, the time “T”. Wait for a response message to the UMIC message until "" has elapsed. That is, if a normal response message is received for the UMIC message before time “T” has passed to the message receiving unit 210, the controller 230 completes the SRNS relocation procedure normally, but before the response message is received, the RLC reset message. However, even if a message with an invalid sequence number is received, a normal response message is waited until the time "T" has elapsed without performing the call truncation procedure.

The message transmitter 220 may retransmit the UMIC message when the normal response message for the UMIC message is not received until the time “T” has elapsed by the message receiver 210, and the timer 240 may be used when the UMIC retransmits. ) Is driven again for a predetermined time, and the message receiving unit 110 repeats the process of waiting for a normal response message for a time "T" as described above.

In this case, the number of driving the timer 240 and the number of retransmission of the UMIC message may be specified at the time of manufacture of the UE 110 or may be specified by a user, but are not limited thereto.

In addition, the controller 230 completes the SRNS relocation procedure when a normal response message is received during the operation of the timer and the retransmission of the UMIC message by the number of times designated by the message receiver 210, and otherwise, performs the call truncation procedure. do.

As such, the apparatus 200 for preventing call truncation between base station controllers according to an embodiment of the present invention is a sequence number of a message exchanged between the UE 110 and a new RNC during an RNC handover between the UE 110. This prevents call truncation that occurs if the SRNS relocation procedure does not complete normally due to mismatches.

3 is a flowchart illustrating a method for preventing call truncation at a boundary point between base station controllers according to an embodiment of the present invention. In this case, the message transmitted and received in the flowchart of FIG. 3 may be understood as transmitted and received based on the UE 110.

As shown, the method for preventing call disconnection at the boundary point between the base station controller according to an embodiment of the present invention, when the UE 110 first receives a UMI message from the new RNC (S110), UE (110) In step S120, the UMIC, which is a confirmation message for the received UMI message, is transmitted. In this case, since an embodiment of the present invention is based on the SRNS relocation procedure between the RNC 124 and the UE 10, it may be understood that the UMIC message is transmitted to the RNC 124. In addition, the UE 110 may perform a process of resetting a sequence number to exchange a message with a new RNC before transmitting a UMIC message.

In addition, the controller 230 drives the timer 240 together with the transmission of the UMIC message (S130). In this case, the time at which the timer 240 is driven may be predefined or specified by the user, but is not limited thereto.

The controller 230 determines whether the driving time of the timer 240 has elapsed (S150) when the RLC reset message or the message having an invalid sequence number is received by the message receiver 210 (S150). If the driving time of the timer 240 has elapsed, the received message is ignored. Otherwise, the message transmitter 220 causes the UMIC message to be retransmitted (S160). In this case, the RLC reset message or the message having an invalid sequence number in step S140 will be referred to as an invalid message.

In addition, the controller 230 restarts the timer 240 together with the retransmission of the UMIC (S170).

If the normal response message is received after the timer 240 is restarted and before the driving time has elapsed, the controller 230 completes the SRNS relocation procedure. Otherwise, the control unit 230 retransmits or disconnects the UMIC message. The procedure will be performed.

In this case, the number of driving of the timer 240 and the number of retransmissions of the UMIC message may be specified in advance or specified by a user, but are not limited thereto. In addition, the controller 230 repeatedly performs the above-described UMIC transmission and timer driving process a specified number of times before performing the call disconnection procedure.

4 is a flowchart illustrating a method for preventing call truncation between base station controllers according to an embodiment of the present invention. In this case, FIG. 4 may be understood to illustrate the flow of messages in the RRC layer and the RLC layer respectively present in the UE 110 and the RNC 124, and the UE 110 may be referred to as “first RRC layer” and “first”. 1RLC layer "and the RNC 124 will be referred to as" second RRC layer "and" second RLC layer ". 4 illustrates a case where a response message is received within a timer driving time, and FIG. 5 illustrates a case where a response message is not received within a timer driving time.

As shown, the method for preventing call truncation between base station controllers according to an embodiment of the present invention, first transmits a UMI message from the second RRC layer 340 to the first RRC layer 310 (S210). This UMI message may be understood to be sent to the UE 110 in a new RNC.

Thereafter, the UMIC message for the UMI message transmitted from the first RRC layer 310 is transmitted to the second RRC layer 340 (S220). In this case, after transmitting the UMIC message in the first RRC layer 310, the UE 110 waits for receiving a response message to the transmitted UMIC message.

The first RRC layer 310 drives the timer 230 for a predetermined time T together with the transmission of the UMIC message (S230).

When the RLC reset message is received from the second RLC layer 330 to the first RLC layer 320 without receiving a response message for the UMIC message while the timer 240 in operation S230 is operated (S240). In the first RLC layer 320, an RLC reset procedure is performed (S250), and in the first RRC layer 310, an RLC reset message is received from the first RLC layer 320 (S260). It does not perform the call cutting procedure until the drive time of the timer 240 has elapsed (S270).

If the response message to the UMIC message is not received until the time T, at which the timer 240 is driven, elapses (S280), the first RRC layer 310 retransmits the timer 240. It is driven (S290).

If the response message is not normally received after step S290, the above-described steps S280 and S290 are repeatedly performed as many times as the specified number of times.

Meanwhile, when the response message is normally received after step S290 (S300), the first RRC layer 310 receives the response message (S310) and terminates the UMI procedure with respect to the received response message. In this case, the steps S300 to S320 may be understood as the timer 240 restarted in the step S290 does not expire. In addition, it has been described that the UMI procedure is terminated in step S330, which is described as the UMI procedure because FIG. 4 is performed by the UMI message, and it can be understood that the SRNS relocation procedure is completed.

Of course, the above-described case in which the RLC reset message is received is described as an example, but this is only an example to help understanding of the present invention, and the present invention is not limited thereto and the sequence number of the message is not valid. The method of FIG. 4 described above may be applied.

As such, the method for preventing call truncation at the boundary point between the base station controllers according to an embodiment of the present invention may be performed by the RLC reset message or the UE 110 when the UE 110 does not receive a response message from the RNC 124 upon handover. When receiving an invalid message, it is possible to prevent the case where the call disconnection occurs in the UE (110).

On the other hand, the components or '~' used in this embodiment is software such as tasks, classes, subroutines, processes, objects, execution threads, programs, or FPGAs (field-) that are performed in a predetermined area on the memory. It may be implemented in hardware such as a programmable gate array (ASIC) or an application-specific integrated circuit (ASIC), or may be a combination of the above software and hardware. The component or 'unit' may be included in a computer readable storage medium, or a part of the components may be distributed and distributed to a plurality of computers.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains have various permutations, modifications, and modifications without departing from the spirit or essential features of the present invention. It is to be understood that modifications may be made and other embodiments may be embodied. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

1 is a block diagram illustrating a UMTS communication network in accordance with an embodiment of the present invention.

2 is a block diagram illustrating an apparatus for preventing call truncation at a boundary point between base station controllers according to an embodiment of the present invention.

3 is a flow chart illustrating a method for call truncation at a boundary point between base station controllers in accordance with an embodiment of the present invention.

4 is a flow diagram illustrating a method for call truncation at a boundary point between base station controllers in accordance with an embodiment of the present invention.

* Description of the main parts of the drawings *

110: user terminal

120: wireless access network

130: core network

140: external network

210: message receiving unit

220: message transmitter

230: control unit

240: timer

Claims (11)

Upon handover from the first base station controller to the second base station controller, receiving a message from the second base station controller informing the switch of the base station controller; Sending a confirmation message for the received message to the second base station controller; And When transmitting the acknowledgment message, driving a timer for a predetermined time and waiting to receive a response message for the acknowledgment message until the timer expires. The method of claim 1, Waiting to receive the response message, the RRC (Radio Resource Control) layer, the method for preventing call disconnection at the boundary point between the base station controller comprising the step of waiting for the reception of the response message. The method of claim 2, And the RRC layer ignores a reset message or a message of an invalid sequence number received before the timer expires. The method of claim 1, Resending the confirmation message if the response message is not received until the timer expires; And And re-starting the timer upon retransmission of the acknowledgment message. The method of claim 4, wherein Retransmitting the acknowledgment message and re-starting the timer are repeated for a predetermined number of times when the response message is not received. The method of claim 5, wherein And performing a call truncation procedure if the response message is not received even after retransmitting the acknowledgment message and restarting the timer a predetermined number of times. A message receiving unit for receiving a message informing of a switchover of the base station controller from the second base station controller when handing over from the first base station controller to the second base station controller; A message transmitter which transmits a confirmation message for the received message to the second base station controller; A timer running for a predetermined time when the confirmation message is transmitted; And And a controller for performing a switching procedure between the base station controllers according to whether the response message to the confirmation message is received until the timer expires. The method of claim 7, wherein The control unit, if the response message is received before the timer expires, the apparatus for preventing call disconnection at the boundary point between the base station controllers to complete the switching procedure between the base station controllers. The method of claim 7, wherein And the control unit is configured to prevent call truncation at a boundary point between base station controllers that ignores reception of a reset message or a message of an invalid sequence number before the timer expires. The method of claim 7, wherein The control unit, if the response message is not received until the timer expires, retransmits the confirmation message a predetermined number of times, and the apparatus for preventing call disconnection at the boundary point between the base station controller to restart the timer. The method of claim 8, And the control unit performs call disconnection at a boundary point of a base station control period when the response message is not received even after the retransmission of the confirmation message and the timer restart.

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