KR20040074720A - Method for processing of hand over against restriction of the length of sccp cr - Google Patents

Abstract

PURPOSE: A method for processing handover against the length limitation of a CR(Connection Request) message by a signaling connection control layer is provided to effectively transmit a relocation request message through an SCCP(Signaling Connection Control Part). CONSTITUTION: When a relocation request is received from a source base station controller in order to request handover(S600), the size of a relocation request message to be transmitted to a target base station controller is compared with a maximum user size(namely, 130 bytes) of a CR message(S610). If the size of the relocation request message exceeds 130 bytes, the CR message which user data does not exist is transmitted(S620) and the relocation request message is included in the DT1(Data form) message and then transmitted(S630). If the size of the relocation request message does not exceed 130 bytes, the relocation request message is transmitted through the CR message(S640).

Description

Handover processing method according to length restriction of access request message by signaling access control layer {METHOD FOR PROCESSING OF HAND OVER AGAINST RESTRICTION OF THE LENGTH OF SCCP CR}

The present invention relates to a mobile communication system, wherein when a mobile communication terminal is in a handover region, a radio access network application layer (RANAP) message is transmitted from a source base station controller to a target base station controller through a signaling access control layer (SCCP) message. It is about how to.

Today, due to the development of the telecommunications industry, the code division multiple access (CDMA) is referred to as 'CDMA'. The services provided by the mobile communication system are not only voice services but also large capacities such as packet data and circuit data. It is evolving into multimedia communication that transmits data.

First, a network structure of the mobile communication system will be described with reference to FIG. 1.

1 is a diagram schematically illustrating a structure of a general mobile communication system. The mobile communication system is a UMTS (Universal Mobile Terrestrial System) mobile communication system, a core network (hereinafter referred to as "CN") 100 and a plurality of radio network subsystems (RNS) And a user terminal (hereinafter referred to as UE) 130. The CN manages information of UEs and performs mobility management, session management, and call management. The RNS is responsible for delivering data transmitted from the CN to the user through an air interface. The RNSs 110 and 120 include a radio network controller (RNC) 111 and 112 and a plurality of base stations Node Bs 113 to 116. do. For example, the RNS 110 includes the RNC 111, the base station 113, and the base station 115, and the RNS 120 includes the RNC 112, the base station 114, and the base station 116. do. Although two base stations Node B are shown in one RNC 111 and 112 above, it is obvious that a larger number of base stations are connected.

The RNCs 110 and 120 are referred to as a Serving RNC (hereinafter referred to as SRNC), a Drift RNC (hereinafter referred to as DRNC), and a Controlling RNC according to their operation. Are classified as). The SRNC refers to an RNC that manages information of each UE belonging to the SRNC and is responsible for data transmission with the CN 100 through an Iu interface, and the DRNC indicates that the SRNC data is stored in the UE. If it is transmitted and received to the SRNC via a different RNC is another RNC. The CRNC is an RNC that controls each of the base stations. In FIG. 1, when the RNC 111 manages the information of the UE 130, the RNC 111 operates as an SRNC for the UE 130, and the UE 130 moves to the UE 130. ) Data is transmitted and received through the RNC 112, the RNC 112 becomes a DRNC for the UE 130, and the RNC 111 controlling the base station 113 communicating with the UE 130. ) Becomes the CRNC of the base station 113. As described above, information and data of the UE 130 are transmitted and received between the CNs through the SRNC.

The RAN (Radio Access Network) consisting of the one or more RNS (110, 120) and CN (100) is connected to the Iu interface as described above, the Iu interface is a radio standard for handling the system exchange, routing and service control Is an open interface dividing into RAN and CN.

Hereinafter, a protocol structure between the RAN and the CN will be described with reference to FIG. 2.

Each plan of the Iu interface shares a common Asynchronous Transfer Mode (ATM) transmission used for all plans. In addition, the physical layers (PHYs) 206 and 216 interface with physical media such as optical fibers, wireless sections, and coaxial cables. Implementation of a physical layer such as SONET, STM1, or E1 can be chosen as a transport technology that is standardized and easily obtainable.

On the other hand, the protocol stack on top of the Broad Band SS7 (Signalling System # 7) protocol of the RAN and CN is composed of a Radio Access Network Application Part (RANAP), the CN is a CC (for performing the function described above) Call Control (207), Session Management (208), Mobility Management (209), and GPRS Mobility Management (GMM) 210 are added.

The application layer has a hierarchical structure of SCCP (Signaling Connection Control Part) 202 and 212, MTP3-B (Message Transfer Part) 203 and 213, and SAAL (Signalling ATM Adaptation Layer).

Details of the above layers are described in 3GPP 25.413, a W-CDMA standard specification. Hereinafter, only RANAPs 201 and 211 and SCCPs 202 and 212 related to the present invention will be described in more detail. .

The RANAPs 201 and 211 are all signaling information defined for a radio network layer as a signaling protocol on Iu. The functionality of the RANAP is implemented by various RANAP basic procedures (EPs), and the functionality of each RANAP requires the execution of one or more EPs. Each EP consists only of a request message or a request and response message pair, one request message and one or more response messages. The RANAP handles relocation of SRNC or handover between RNSs and manages a radio access bearer (RAB). In addition, it releases all temporarily allocated resources in relation to the determined UE, and serves to transmit a signal between the UE and the CN.

On the other hand, in the message of the Iu interval, the RANAP message is set as the user data of the SCCP message, thereby completing a message format. Hereinafter, the SCCP connection establishment procedure will be described with reference to FIG. 3.

First, when an SCCP connection is requested (S301) from a first network component to a second network component through a CR (Connection Request) message, the second network component is connected to the first network component. Complete the setup of the SCCP connection by sending a message (S302). When the SCCP connection between the networks is completed, various procedures through data transmission and reception through a DT1 (Data Form) message is performed (S303, S304).

After the predetermined procedures are performed, when requesting SCCP disconnection from the first network component to the second network component through a RLSD (Released) message (S305), the second network component is connected to the first network component. By sending a Release Complete (RLC) message to notify the SCCP connection release (S306).

On the other hand, when the mobile terminal performs a handover, the CN relocates the radio resource allocation from the source base station controller (Serving RNC) to the target base station controller (Target RNC), and the RANAP message for relocating the radio resource allocation is As described above, it may be implemented through the SCCP message configuration procedure on the lu interface.

Hereinafter, the SCCP connection establishment procedure described above with reference to FIG. 4 will be described in detail by applying to the RANAP message delivery procedure in the handover procedure related to the present invention.

First, a Relocation Required message from a source base station controller (Source RNC) to a CN is transmitted through a DT1 message of the SCCP (S401), thereby starting a handover procedure. Upon receiving the relocation request message, the CN transmits a relocation request message to a target base station controller (Target RNC) through a CR message (S402) to make a handover request. The target base station controller performs allocation for the corresponding radio resource, and transmits a relocation request response message to the CN through a CC message (S403).

The CN notifies the source base station controller through a DT1 message that the radio resource allocation of the target base station controller is completed (Relocation Command) (S404).

Meanwhile, the target base station controller notifies the CN that the handover is performed (Relocation Detect) to the CN through a DT1 message (S405), and notifies the CN to the CN through the DT1 message (S406) that the handover is completed.

When the handover is completed as described above, the CN transmits an Iu release command (Iu Release Command) to the source base station controller through a DT1 message (S407), and the source base station controller completes the release of the Iu connection ( Iu Release Complete) to notify the CN (S408). When the procedure is completed, in order to release the SCCP connection initially established between the source base station controller and the CN, an RLSD message is requested from the CN to the source base station controller to request release of the SCCP connection (S409). The source base station controller receiving the RLSD message releases an SCCP connection and transmits an RLC message to the CN (S410), thereby notifying that the SCCP connection release is completed.

Meanwhile, as described above, in the case of the relocation request, which is a RANAP start message to the target base station controller during the handover procedure, since a request for a connection request is requested to the SCCP of the base station controller, the 3GPP standard (3GPP 25.413). ) Must be delivered in an SCCP CR message.

According to the SCCP standard (ITU-T Recommendation Q.713), the SCCP CR message has a size of 3 to 130 bytes (Bytes or Octets) as shown in Table 1 below.

However, in applying the SCCP in the conventional mobile communication system, the data size of the CR message was not a problem because it did not exceed 130 bytes, but as described above, the relocation that is the RANAP start message during the handover procedure in the third generation mobile communication as described above. In the case of a relocation request message, it will exceed 130 bytes. That is, since one terminal has a plurality of traffic channels, and all the information must be transferred from the source base station controller to the target base station controller during handover, the amount of information becomes quite large.

Accordingly, when the relocation request message is delivered as a CR message of an SCCP, when the relocation request message exceeds 130 bytes, the maximum value of the user data area of the CR message, the relocation request message cannot be transmitted. As a result, normal handover procedures cannot be made.

Accordingly, an object of the present invention is the maximum user data size of a CR message when transmitting a radio access network application layer (RANAP) message through a signaling access control layer (hereinafter referred to as SCCP) message from a source base station controller to a target base station controller. The present invention provides a method for efficiently transmitting a relocation request message over which the SCCP is exceeded.

In a mobile communication system, a method for transmitting a signaling connection control layer (SCCP) message from a source base station controller to a target base station controller when the mobile communication terminal is in a handover region, In the core network receiving the relocation request message transmitted from the source base station controller, transmitting a connection request (CR) message not including the relocation request message to the target base station controller; and transmitting the relocation request message to the first data form DT1. ) A process of transmitting through a message.

In addition, the present invention transmits the relocation request message through the connection request message when the size of the relocation request message to be transmitted is not greater than the maximum user data size of the access request (CR) message defined in the signaling connection control layer. When the relocation request message is larger than the maximum user data size of the first data form DT1 message, the relocation request message is divided into plural numbers and sequentially transmitted through the first data form DT1 message. It is characterized by.

In addition, the present invention for achieving the above object is a method for transmitting a signaling connection control layer (SCCP) message in a mobile communication system, the signaling connection transmitted from a first network component to a second network component If the size of the radio access network application layer (RANAP) message included in the data area of the access request (CR) message of the control layer (SCCP) message is larger than the maximum size of the data area of the access request message, the radio And transmitting the access network application layer message through the first data form DT1 message of the signaling connection control layer (SCCP) message.

1 is a diagram illustrating a network structure of a mobile communication system according to the prior art.

2 is a diagram illustrating a protocol structure of a lu interface according to the prior art.

3 is a flowchart illustrating a connection establishment and release procedure by an SCCP message according to the prior art.

4 is a flowchart illustrating a handover procedure using an SCCP message according to the prior art.

5 is a flowchart illustrating a handover procedure by an SCCP message according to the present invention.

6 is a flowchart illustrating a handover procedure by an SCCP message according to an embodiment of the present invention.

DETAILED DESCRIPTION A detailed description of preferred embodiments of the present invention will now be described with reference to the accompanying drawings. In the following description of the reference numerals to the components of the drawings it should be noted that the same reference numerals as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or a chip designer, and the definitions should be made based on the contents throughout the present specification.

In the case of the relocation request message defined in the 3GPP standard (25.413), it has a configuration as shown in Table 2 below, and the actual amount of data exceeds at least 200 bytes in the packet service domain.

Since the relocation request message of RANAP configured as described above exceeds the maximum data size of the CR message specified in the SCCP standard (ITU-T Recommendation Q.713), 130 bytes. We present a method for effective transmission without compromising the SCCP specification.

According to the SCCP standard, a DT1 message includes a user data area of 2 to 256 bytes as shown in Table 3 below.

Accordingly, by allowing the relocation request message to be transmitted through the DT1 message, it is possible to overcome the limitation of the transmittable message size caused by the CR.

Hereinafter, a procedure of transmitting the relocation request message through a DT1 message will be described with reference to FIG. 5.

Referring to FIG. 5, when the CN transmits a relocation required message from the source base station controller through a DT1 message to request a handover, the CN transmits a CR message to the target base station controller (S501). At this time, by setting the size of the user data area of the CR message to 0 and transmitting to the target base station controller (S502), only the request for SCCP access is performed. That is, the CR message is transmitted in the state that the relocation request message is not included. After receiving the CR message, the target base station controller establishes an SCCP connection, and sets the user data size to 0 in the CC message as a response and transmits the data to the CN (S503).

After receiving the CC message, the CN performs the handover request by transmitting the relocation request message to the target base station controller through a DT1 message (S504). Upon receiving the relocation request message, the target base station controller, which has been allocated the corresponding radio resource, transmits a relocation request acknowledgment message to the CN through a DT1 message (S508).

The following procedure is the same as the steps S404 to S410 described with reference to FIG. 4. That is, the CN notifies the source base station controller through a DT1 message that the radio resource allocation of the target base station controller is completed (Relocation Command) (S506), and the target base station controller indicates that the handover is performed (Relocation Detect). Notify through CN (S507), and informs the CN through the DT1 message (S508) that the handover is completed (Relocation Complete).

When the handover is completed as described above, the CN transmits a corresponding Iu release command (Iu Release Command) to the source base station controller through a DT1 message (S509), and the source base station controller completes the release of the Iu connection ( Iu Release Complete) to notify the CN (S510). When the procedure is completed, in order to release the SCCP connection initially established between the source base station controller and the CN, an RLSD message is requested from the CN to the source base station controller to request release of the SCCP connection (S511). The source base station controller receiving the RLSD message releases an SCCP connection and transmits an RLC message to the CN (S512), thereby notifying that the SCCP connection release is completed.

By doing so, the problem that the Relocation Required message is not transmitted to the CR message due to the size limitation of the data area of the CR message is solved, and handover regardless of the size of the Relocation Required message. The procedure will always go smoothly.

Meanwhile, the procedure may be selectively processed in parallel with the conventional procedure according to the size of the relocation required message. Hereinafter, an embodiment of the present invention will be described with reference to FIG. 6.

First, when there is a relocation request (S600) according to a handover from a source base station controller, the size of a relocation required message to be transmitted to a target base station controller is determined by the maximum user size (ie, 130 bytes) of the CR message. Compare (S610).

As a result of the comparison, if the size of the relocation request message exceeds 130 bytes, as described above with reference to FIG. 5, the user does not have the user data in the CR message and transmits it (S620), and then includes the relocation request message in the DT1 message. send.

On the other hand, if the size of the relocation request message does not exceed 130 bytes, the relocation request message is transmitted through the CR message (S640).

However, it is also possible to unconditionally transmit the relocation request message through the DT1 message without comparing the data size.

Additionally, even when the size of the relocation request message exceeds 256 bytes, which is the maximum user data size of the DT1 message, it is possible to transmit through the DT1 message by the same method. In more detail, when the relocation request message exceeds 256 bytes, the fragmentation relocation request message is transmitted by the target base station controller after being transmitted through the DT1 message several times after segmentation in 256 byte units. Can be reassembled. The division / recombination of the user data of the DT1 message as described above may be implemented through a general method of division / recombination of the DT1 message.

As described above, in the detailed description of the present invention, specific embodiments have been described. However, various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

According to the present invention, the user data size in the SCCP CR message can be supported from the 130 bytes of the existing standard to 256 bytes or more using the partitioning function such as the DT1 message level, so that the user can use the SCCP CR message in a future application. Even if the data size is 130 bytes or more messages can be easily implemented.

Claims (10)

A mobile communication system, comprising: transmitting a signaling connection control layer (SCCP) message from a source base station controller to a target base station controller when the mobile communication terminal is in a handover region, Transmitting a connection request (CR) message not including a relocation request message to the target base station controller in the core network receiving the relocation request message transmitted from the source base station controller; And transmitting the relocation request message through a first data form (DT1) message. The method of claim 1, The size of the relocation request message to be transmitted is larger than a maximum user data size of a connection request (CR) message defined in the signaling connection control layer. The method of claim 1, If the size of the relocation request message to be transmitted is not greater than the maximum user data size of the access request (CR) message defined in the signaling access control layer, the relocation request message is transmitted through the access request message. . The method according to claim 2 or 3, The maximum user data size of the access request message is 130 bytes. The method of claim 1, The user data size of the first data form (DT1) message is 2 to 256 bytes. The method of claim 1, When the relocation request message is larger than the maximum user data size of the first data form DT1 message, the relocation request message is divided into a plurality and sequentially transmitted through the first data form DT1 message. The method. The method of claim 1, After the core network transmits a connection request message, And the target base station controller transmits a connection request response message to the core network. The method of claim 1, The target base station controller receiving the access request message establishes a connection of a signaling access control layer. A method for transmitting a signaling connection control layer (SCCP) message in a mobile communication system, The radio access network application layer (RANAP) included in a data area of a connection request (CR) message of the signaling connection control layer (SCCP) message transmitted from a first network component to a second network component; Application Part) When the size of the message is larger than the maximum size of the data area of the connection request message, the radio access network application layer message is transmitted through the first data form (DT1) message of the signaling connection control layer (SCCP) message The method comprising the step of. The method of claim 9, The network component is any one selected from a core network and a base station controller.