KR100413191B1 - Soft handover path control method by mobile communication network - Google Patents

Abstract

The present invention relates to a soft handover path control method in a mobile communication network and a computer-readable recording medium recording a program for realizing the method. The present invention relates to a RAN configuration technology using a G-RNC configured by recycling an RNC in an asynchronous RAN. And a soft handover path control method in a radio access network (RAN) for efficiently setting an information transfer path between an RNC and a G-RNC by a path extension method, and to provide a soft handover service between RNCs. In case of handover between the controllers (RNCs), the RNSAP and the access link control application protocol (ALCAP) messages are processed through common line signaling between adjacent RNCs to dynamically switch virtual channel (SVC) connections. Setting up a first step; And a second step of transmitting signal information and traffic data from the RNC to another RNC as it is through a preset permanent virtual channel (PVC) connection without performing a signaling function in a global RNC (G-RNC).

Description

Soft handover path control method by mobile communication network

The present invention provides a fast soft handover path control method between a control station (ie, a radio network controller (RNC)) in a radio access network (RAN) of a mobile communication system and a program for realizing the method. In particular, the present invention relates to a computer-readable recording medium for recording a computer, and more particularly, to an asynchronous mobile communication system (WCMS: Wideband CDMA Mobile System) based on a next generation mobile communication network such as International Mobile Telecommunication (IMT-2000) or Universal Mobile Telecommunications System (UMTS). The present invention relates to a fast soft handover path control method between RNCs using G-RNC (Global RNC) in a radio access network (RAN).

Through the first generation cellular cellular communication and the second generation cellular mobile communication, the third generation IMT-2000 mobile communication technology is proposed based on the synchronous cdma2000 method which is proposed mainly in the United States and Europe and Japan. It is divided into two asynchronous wideband code division multiple access (W-CDMA) schemes and is being actively researched and developed around the world. After the third generation, the wired / wireless network will be integrated, personal mobility will increase, and the concept of high speed and capacity of transmission data will be continuously developed. Providing efficient handover is one of the most important core technologies of mobile communication.

Currently, the third generation mobile communication technology is actively being researched and developed globally, and in the situation where core technology development is directly related to national competitiveness, a path control method for efficient soft handover between RNCs in asynchronous RAN must be provided. It is one of important technologies and can be applied to next generation mobile communication.

Handover is a function that provides continuity of a call without disconnection when the subscriber moves to another base station cell area in the mobile communication system. Currently, the purpose is to ensure the movement of the terminal while maintaining the negotiated quality of service of the connection in service, and to minimize the transmission interruption time so that the user does not detect the occurrence of the handover is a seamless handover.

Handover is divided into soft handover and hard handover according to the processing method, and the hard handover is a method of disconnecting a call path with an existing base station and then connecting a call path with a new base station. As a result, the call is instantly disconnected. In addition, soft handover connects the call path with the new base station to which the subscriber has moved and the call path with the previous base station at the same time, and selects the call path with excellent wireless quality, and the call with the existing base station reduces the quality below the threshold. When the existing call path is cut, the present invention describes a case of soft handover between RNCs.

The handover rerouting is performed by path extension or path rerouting. The handover rerouting method by path extension performs handover by continuously extending an additional path of the virtual connection from the base station before the handover to the new base station. It can reduce the time, easily ensure the integrity of the transmitted cell, and if the terminal reconnects to the previously visited base station, a loop may occur in the path but quick handover is possible and cell loss prevention and ordering are easy. I can guarantee it.

In order to provide handover control, which is an important technology for providing mobility of terminals, to be efficiently provided in an asynchronous radio access network (RAN) based on an asychronous transfer mode (ATM), ATM as well as general matters required in the existing mobile communication network are unique to ATM. As an additional requirement of broadband service, efficient bandwidth management technology of broadband service is needed, and next-generation mobile network will be mainly focused on pico or micro cell environment with small cell size. Will be even more important than in the mobile communication environment. Accordingly, there is an urgent need for an efficient path control technique for rapidly and broadly providing soft handover services in a third generation asynchronous RAN.

The present invention has been proposed in order to meet the above-described needs, and it is effective to efficiently transfer information transmission path between RNC and G-RNC by RAN configuration technology and path extension method applying G-RNC configured by recycling RNC in asynchronous RAN. It is an object of the present invention to provide a soft handover path control method for providing a soft handover service between RNCs and a computer-readable recording medium on which a program for realizing the method is recorded.

1 is an exemplary configuration of a mobile communication control station (RNC) to which the present invention is applied.

2 is an exemplary configuration diagram of a global radio access network (G-RNC) to which the present invention is applied.

3 is a configuration diagram of a soft handover path between RNCs through a G-RNC to which the present invention is applied.

4 is an explanatory diagram showing a path control method in G-RNC according to the present invention;

5 is a diagram illustrating a protocol stack configuration between an RNC and a G-RNC according to the present invention.

6 is a flowchart illustrating a method for controlling a soft handover path between an RNC and a G-RNC according to the present invention.

* Explanation of symbols for the main parts of the drawings

10: ATM Switch 11: Switch Control Processor (SCP)

12: ATM matching unit (AIM) 13: ATM switching unit (ASM)

14: RAS-B 15: RAS-T

16: RAS-N 17: RAS-R

18: Radio Control Subsystem (RCS)

In order to achieve the above object, the present invention provides a soft handover path control method in a radio access network (RAN), wherein when a handover occurs between radio network controllers (RNCs), a radio network subsystem application unit (RNSAP) is provided between adjacent RNCs. Processing a Connection Link Control Application Protocol (ALCAP) message via common line signaling to establish a dynamically switched virtual channel (SVC) connection; And a second step of transmitting signal information and traffic data from the RNC to another RNC as it is through a preset permanent virtual channel (PVC) connection without performing a signaling function in a global RNC (G-RNC). It is done.

In addition, the present invention provides a soft handover path control method in a radio access network (RAN), wherein a connection identifier to be negotiated for use between a radio network controller (RNC) and a global RNC (G-RNC) in the radio access network (RAN). And setting a system-specific control message path to be initially set; Setting a path to be used for soft handover between RNCs connected in the G-RNC and a control message path in the G-RNC; A third step of establishing a connection in a serving RNC (S-RNC) according to the call setup request of the mobile subscriber; A fourth step of adding a connection branch from the S-RNC to the G-RNC when a soft handover occurs between the RNCs according to a result of handover measurement and determination processing according to a subscriber's movement to another RNC; A fifth step of selecting and delivering a cell of good quality among traffic received from the S-RNC and the D-RNC for a predetermined period in a D-RNC according to a connection branch; According to the processing result according to the connection branch deletion determination, the S-RNC releases the path connected to the previous base station, and the S-RNC is transmitted through the G-RNC from the D-RNC to which the newly moved subscriber is connected. A sixth step of uninterrupted transmission of the handovered traffic between RNCs through a path to a previously established network (CN / GPRS) of; And a seventh step of recovering all wired and wireless resources allocated to the S-RNC and the D-RNC according to the call release of the mobile subscriber.

Meanwhile, the present invention provides a connection for use between a radio network controller (RNC) and a radio network controller (RNC) and a G-RNC (Global RNC) in a radio access network (RAN) having a processor for soft handover path control. A first function of negotiating an identifier and setting a system-specific control message path to be initially set up; A second function of setting a path to be used for soft handover between RNCs connected in the G-RNC and a control message path in the G-RNC; A third function of establishing a connection in a serving RNC (S-RNC) according to a call setup request of a mobile subscriber; A fourth function of adding a connection branch from the S-RNC to the G-RNC when a soft handover occurs between the RNCs according to a result of handover measurement and determination processing according to a subscriber's movement to another RNC; A fifth function of selecting and delivering a cell of good quality among traffic received from the S-RNC and the D-RNC for a predetermined period in a D-RNC (Drift RNC) according to the addition of a connection branch; According to the processing result according to the decision to remove the connection branch, the S-RNC releases the path connected to the previous base station, and the newly moved subscriber is located in the S-RNC through the G-RNC from the D-RNC connected to the subscriber; A sixth function for uninterrupted transmission of the handovered traffic between RNCs over a path to a previously established network (CN / GPRS) of; And a computer-readable recording medium having recorded thereon a program for realizing a seventh function of recovering both the wired and wireless resources allocated to the S-RNC and the D-RNC in response to the call release of the mobile subscriber.

In the present invention, the ATM-based asynchronous radio access network (RAN) between the adjacent RNCs is dynamically processed by the Radio Network Subsystem Application Part (RNSAP) and the Access Link Control Application Protocol (ALCAP). Signal information from the RNC is established through a Switched Virtual Channel (SVC) connection, and through a Permanent Virtual Channel (PVC) connection, which is preconfigured without performing a signaling function to the G-RNC (Global RNC). And by transmitting the traffic data to the other RNC as it is, to reduce the connection setup time due to signaling processing, to provide a fast soft handover function in the wide-area RAN using G-RNC.

To this end, in the present invention, the G-RNC is a switch that performs the role of a higher layer interconnecting up to 12 RNCs. In addition, when setting the soft handover path between RNCs, the RNC uses an SVC connection control scheme, and in the G-RNC, four PVCs are set as traffic transmission paths to satisfy handover traffic capacity between the RNCs. In other words, SVC connection is dynamically established between RNSAP and ALCAP processing between neighboring RNCs, and G-RNC transfers signaling information and traffic data from RNCs to opposite RNCs through preset ATM paths without performing signaling functions. .

Accordingly, the present invention sets up the SVC connection in the RNC and the PVC connection in advance in the G-RNC during the soft handover between RNCs, thereby reducing the connection establishment time by signaling in the RNC and G-RNC wired sections, thereby enabling high-speed soft handovers. It is easy to construct an economical network by providing functions and building a RAN using G-RNC to increase the ability to provide soft handover service and resource efficiency, and to simplify the network configuration and management.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary configuration diagram of a mobile communication control station to which the present invention is applied and shows a configuration of an asynchronous radio network controller (RNC).

In the asynchronous radio network controller (RNC), the ATM switch 10 performs a connection control function to quickly deliver mobile multimedia real-time and non-real-time services including control information and voice, text, and video services to the subscribers.

ATM switch function (ATM switch 10) is a switch control processor (SCP) 11 performing the connection control and operation maintenance functions of the ATM switch 10, ATM to perform ATM cell header conversion and cell traffic data collection A matching unit (AIM) 12, which consists of an ATM switching unit (ASM) 13 that performs cell routing functions within the ATM switch fabric. In addition, various radio access systems (RAS) 14 to 17 and a control module (radio control system (RCS: Radio Control System) 18) are connected through an ATM matching unit (AIM) 12. .

A radio access system (RAS) 14 to 17 is a RAS-B 14 that performs a joining function with a base station, a RAS-T 15 that performs voice and data traffic processing, and a core network (CN) / RAS-N 16 performing a matching function with a general packet radio service (GPRS), and a RAS-R 17 performing a G-RNC matching function for handover between adjacent radio network controllers (RNC).

The radio control system (RCS) 18 is an access control processor (ACP) that performs mobile call protocol processing and resource management, and an operation and maintenance that performs overall operation management and maintenance of a radio network controller (RNC). Access Signaling Processor (ASP) to perform common protocol (No. 7) signal protocol processing with a processor (OMP: Operation Maintenance Processor) and CN / GPRS, and an access path processor serving as a controller for ATM switch control. (ARP: Access Routing Processor).

The present invention relates to a radio network controller (RNC) and a G according to a radio access network (RAN) configuration technology and a path extension method using a G-RNC (Global RNC) configured by recycling a radio network controller (RNC) in an asynchronous radio access network (RAN). The present invention relates to a method for efficiently setting an information transmission path between -RNCs (Global RNC).

A radio access network (RAN) for handover service between radio network controllers (RNCs) directly connects links to all adjacent radio network controllers (RNCs) to communicate, or provides an ATM exchange that provides a connection function between radio network controllers (RNC). A G-RNC (Global RNC) that performs a system role may be added, and a wireless network controller (RNC) and a G-RNC (Global RNC) may be connected by a single link.

If G-RNC (Global RNC) is not adopted, as the number of radio network controllers (RNCs) to be interconnected increases, the price of transmission paths increases rapidly because all links must be directly connected between adjacent radio network controllers (RNCs). In addition, in the radio network controller (RNC), only the access link portion except this can be used for the radio network controller (RNC) itself processing, and the utilization of the system is drastically reduced, and the service area in the radio access network (RAN) is limited. However, when a radio access network (RAN) is configured by applying a global RNC (G-RNC) having a large capacity switching capability, in a radio network controller (RNC), the path between adjacent radio network controllers (RNC) is logical ATM within a single link. It is economical because it is mapped and processed by connection, and the soft handover service area according to the wide area radio access network (RAN) configuration is expanded, and the coping with the addition and deletion of the radio network controller (RNC) is facilitated.

G-RNC (Global RNC) is an ATM switch that functions as a higher layer interconnecting up to 12 radio network controllers (RNCs), and provides traffic, signaling, and operation management between users during soft handover between radio network controllers (RNCs). Provides a route for message delivery. In G-RNC (Global RNC), the Permanent Virtual Channel (PVC) / Permanent Virtual Path (PVP) / Switched Virtual Channel (SVC) connection control method is used for handover path setup time. As a result of analysis according to the operation management and function development cost factors, the PVC connection control method is most suitable, and thus, the present invention describes the soft handover process accordingly.

By setting up several logical ATM connections in the G-RNC (Global RNC) for each adjacent RNC in the link connected between the RNC and G-RNC (Global RNC), G In RNC (Global RNC), only the switching function of ATM layer is performed to provide high-speed soft handover over a wide range of radio access network (RAN) area using link resources more efficiently, and remotely multiplexing in radio access network (RAN). Operation management of a radio transceiver system (RTS) (i.e., base station) and a multiple radio network controller (RNC) (i.e., control station) becomes easy.

In other words, the neighboring radio network controller (RNC) signaling the radio network subsystem application part (RNSAP) and the access link control application protocol (ALCAP) message No. 7 during handover. By processing through, the SVC connection is dynamically set within the range of VPI / VCI preset in the G-RNC (Global RNC) for each radio network controller (RNC), and signaling processing is not performed in the G-RNC (Global RNC). Signal information and traffic data from the radio network controller (RNC) are transferred to the other radio network controller (RNC) as it is through a preset ATM path. Accordingly, a high-speed soft handover function is provided by reducing service delay time due to signaling processing during handover in G-RNC (Global RNC) and wireless using G-RNC (Global RNC) with large capacity switching capability. By constructing access network (RAN), soft handover service is provided in a wider radio access network (RAN) area, and multiple radio transceiver system (RTS) and multiple radio network controller (RNC) in GRAN-RNC Improve operation management ability by remotely managing through Remote Operation Maintenance System (R-OMS) connected to (Global RNC).

Hereinafter, when controlling a high speed soft handover path between radio network controllers (RNCs) using G-RNCs (Global RNCs) in an asynchronous radio access network (RAN), control is performed by PV-PVC, PVC, SVC connection in G-RNCs (Global RNC). Comparison of advantages and disadvantages between methods, configuration of SVC connection control function in radio network controller (RNC) and PVC connection control function in global RNC, radio network controller (RNC) and G-RNC (Global) Protocol stack and execution function for each processor for connection control processing in RNC), initialization process in RNC and Global RNC, and movement of subscriber to other RNC during call An operation process during soft handover in the radio network controller (RNC) and the global RNC (G-RNC) will be described.

Radio access network (RAN) is basically composed of a radio transceiver system (RTS) 21 and a radio network controller (RNC) 22, to build a global radio access network (RAN) (G-RNC (Global RNC) of Figure 2 23 is added and configured.

The radio transceiver system (RTS) 21 is a radio access termination with a user equipment (UE) in accordance with the General Partnership Project (3GPP) radio access standard, and performs radio frequency interface, modulation and channel coding functions.

The radio network controller (RNC) 22 is in charge of the overall control of the switching period and the access link with the mobile terminal, such as power control, handover determination and execution, connection link establishment / release.

Global RNC (G-RNC) 23 reuses the radio network controller (RNC), and consists only of parts necessary to perform the PVC function. The Global RNC (G-RNC) 23 is an ATM switch for providing a soft handover path according to RNSAP and ALCAP communication between 12 radio network controllers (RNCs) 22, and 16 ATM matching units (AIM) and switches. Control Processor (SCP), ATM Switch, Access Path Processor (ARP), Operation and Maintenance Processor (OMP), Remote Alarm Gathering Module (RAGM) and each Radio Network Controller (RNC). It consists of a Radio Access System (RAS) -N for accessing an ATM switch.

Remote operation and maintenance system (R-OMS) 24 which manages and manages multiple radio network controllers (RNCs) 22 and multiple radio transceiver systems (RTSs) 21 that constitute a radio access network (RAN) remotely. It is connected to the Operation and Maintenance Processor (OMP) via Fast Ethernet.

3 is a diagram illustrating a soft handover path configuration between RNCs through a G-RNC to which the present invention is applied, and uses a connection established to a S-RNC (Serving RNC) 31 by a path extension method, and a mobile terminal is a new cell. In the soft handover completion step that completely crosses the boundary, the previous access link connecting the mobile terminal and the selector is removed.

The ALCAP and RNSAP processing unit forms and transmits a handover control message between the Serving RNC (S-RNC) 31 and the Drift RNC (D-RNC) 32, and bearer control messages for adding and deleting handover branches and The radio bearer establishment request message is related.

Accordingly, the handovered traffic is a traffic management unit (THM) which processes traffic through an ATM switch from a link interface module (LIM) -B 33 to which a subscriber who has moved to a DFT RNC (D-RNC) 32 is connected. Handling module (34), and traffic through the ATM switch to the link matching unit (LIM) -N (35) connected to the global RNC (G-RNC). Link matching unit (LIM) -N (36) of the G-RNC (Global RNC) link matching unit (LIM) -N connected to the S-RNC (Serving RNC) 31 through the ATM switch as it is. Route to (37). When traffic passes from the link matching unit (LIM) -N 38 connected to the global RNC (G-RNC) 31 in the Serving RNC (S-RNC) 31 to the traffic management unit (THM) 39 through an ATM switch. Selects a cell of high quality and passes traffic through the link matching unit (LIM) -N 40 connected to the CN / GPRS that S-RNC (Serving RNC) 31 initially set up through the ATM switch. The cell is transmitted without interruption during the soft handover process between the RNCs.

For fast soft handover path control between radio network controllers (RNCs) using G-RNC (Global RNC), the speed of connection rerouting, guarantee of service quality per user, system capacity, ease of operation management, compatibility with other products, Development cost and feasibility should be considered. In FIG. 4, a connection control scheme and advantages and disadvantages of G-RNC (Global RNC) were analyzed.

The PVP and PVC connection control methods are almost similar, and the PVP method only needs to establish a single connection for each radio network controller (RNC) to communicate with, but the PVC method predicts the amount of handover traffic and the radio network controller (RNC) to communicate with. Multiple connections must be established.

The radio network controller (RNC) has a PVC connection for transmitting control information and signaling messages, and an SVC connection that is set dynamically according to mobile call generation. An ATM Adaptation Layer (AAL) is used to increase transmission efficiency of a link. Performs the 2 / AAL5 conversion function. The ATM PVC in the radio network controller (RNC) is a path for transmitting Inter Processor Communication (IPC) messages between each processor board and a Signaling AAL (SAAL) signaling protocol message. Send and receive Only AAL5 is supported in ATM switch, but AAL2 is capable of multiplexing and sending data of multiple subscribers to one ATM connection using ALCAP to increase link efficiency between G-RNC (Global RNC) in Radio Network Controller (RNC). Support the function. In the interface between network controllers (RNCs) within 3GPP standards, it is recommended to establish an AAL2 connection as a handover traffic transmission path, so information of up to 248 subscribers in one ATM connection may be multiplexed and transmitted.

First, when using the PVP connection control scheme 4a in G-RNC (Global RNC), the virtual path switching function and the available VPI capacity must be supported. Since only one handover user traffic propagation path is required between neighboring radio network controllers (RNCs), initial connection establishment processing and management are convenient. In general, however, virtual path switching is not supported in all systems, and the available Virtual Path Identifier (VPI) capacity and VP switching capabilities are often hardware limited and involve additional VP switching software development costs. . Asynchronous G-RNC (Global RNC) is not easy to implement because it lacks VPI coverage and does not support virtual path switching in utopia switch devices in ATM subscriber matching.

On the other hand, when using the PVC connection control method (4b) in the G-RNC (Global RNC), the neighbor radio network controller (RNC) in consideration of the handover traffic capacity prediction between the radio network controller (RNC) and the multiplexing characteristics of the AAL2 connection Since only about four handover traffic forwarding paths need to be set, the development cost is saved because it is easily provided using only the developed virtual channel switching provided by all systems without any hardware change while using the advantages of PVP method. It can save time. The ATM connection control function of the radio network controller (RNC) is recycled, and only the initial connection setting according to the configuration information in the G-RNC (Global RNC) and the PVC setting data according to the handover path need to be changed to establish the connection.

On the other hand, when using the SVC connection control method (4c) in G-RNC (Global RNC), the process is somewhat complicated because the AAL2 connection control and its own signal protocol function must be added, and the handover execution time is long. Connection with other RNC products is not easy. Therefore, when establishing a soft handover path between radio network controllers (RNC), the radio network controller (RNC) uses an SVC connection control scheme, and in G-RNC (Global RNC), a soft handover service is provided by PVC connection control. Is suitable. PVC connection control method in G-RNC (Global RNC) uses ATM switch, so it performs high-speed information transfer using ATM layer cell routing of pre-established connection during handover. The convenience of operation management due to the multiplexed AAL2 connection function can be used as it is, and additional service control by adding additional connection control function and signaling processing overhead in SVC connection method can be provided to provide fast handover. To ensure. In addition, since only the virtual channel switching function provided by all ATM switching systems is easily implemented using pre-developed software without any hardware change, development costs are low and services can be easily provided in the shortest time.

5 is a diagram illustrating a protocol stack configuration between an RNC and a G-RNC according to the present invention. A protocol stack relating to soft handover processing between a radio network controller (RNC) and a radio network controller (RNC) in a G-RNC (Global RNC) is illustrated. And layer-specific performance functions to exchange signal information through a logical Iur interface between RNCs. Here, the Iur access protocol consists of a radio network layer and a transport layer, the radio network layer consists of a radio network control plane and a radio user plane, and the transport layer defines a procedure for physical connection between radio network controllers (RNC). do.

Focusing on a function for processing a protocol related to handover between radio network controllers (RNCs), an access control processor (ACP) in the radio network controllers (RNCs) performs radio resource management with a terminal. Radio Resource Control layer 51, a Radio Network Subsystem Application (RNSAP) 52 terminated at both ends of the Iur interface by a Radio Network Controller (RNC) to a radio network layer protocol for carrying signal information on the Iur interface. ), A connection link control application protocol (ALCAP) processor 53 for setting and releasing a user plane transport bearer as a signal protocol for controlling AAL2 connection of an Iur connection, and a message transmitter (MTP) used as a signal bearer of the AAL2 signaling protocol. : Message Transfer Part) -3b / STP (Signaling Transport Converter) 54, which is a matching protocol between Simple Control Transmission Protocol (SCTP).

No.7 signaling processing on the Iur interface is embedded in the access path processor (ARP), and the IPC API (Application) defined for inter-processor communication in the radio network controller (RNC) in the access control processor (ACP) when transmitting RNSAP or ALCAP messages. When using the Programming Interface, it transfers to the access path processor (ARP) through the ATM switch, and it is transmitted to the other party's Radio Network Controller (RNC) through the No.7 signaling protocol stack. Follow. SCCP 55, which is a signal bearer that is responsible for connection mode and connectionless mode transmission of signaling messages between RNCs, is divided into MTP-3b based and IP based. MTP-3b base is a signal bearer based on No.7 signal link, MTP-3b (56), Service Specific Convergency Function (SSCF) -NNI (57), Signaling Service Connection Oriented Protocol (SSCOP) (58), AAL5 (59), ATM (60) and the like. The IP base is a signal bearer for transmitting signaling messages in the IP base network, and is composed of an M3UA (MTP-3b User Adaptation) 61, an SCTP 62, a UDP / IP 63, an AAL5, and an ATM. Since G-RNC (Global RNC) uses only ATM layer functions, no separate protocol processing is required.

FIG. 6 is a flowchart illustrating a soft handover path control method between an RNC and a G-RNC according to the present invention, and shows a soft handover between a radio network controller (RNC) and a G-RNC (Global RNC) using a path extension method. Indicates a route processing procedure. For convenience of description, descriptions will be made mainly on radio network controllers (S-RNC, D-RNC) and G-RNC (Global RNC).

Wireless network controllers (S-RNC, D-RNC) and G-RNC (Global RNC) both use only VC switching, and use VPI 5-bit (Bit) and VCI (Virtual Channel Identifier) 12-bit. Cells transmitted / received from the radio network controller (RNC) to the ATM matching unit (AIM) of the ATM switch perform cell header conversion functions for the AAL2 / AAL5 in the link matching unit (LIM) -N, but G-RNC (Global RNC) My link matcher (LIM) -N does not require AAL2 / AAL5 conversion. Connection identifier management pre-negotiates the range of available VPI / VCI between all neighboring radio network controllers (RNC) that each RNC can communicate with when the network is established, and the VPI / VCI available within the range when mobile call is requested. Allocates dynamically. In addition, the link matching unit (LIM) -N in the G-RNC (Global RNC) is responsible only for the connection function between the radio network controller (RNC) and the G-RNC (Global RNC), so the received cell is transferred as it is, and the G-RNC The ATM switch in (Global RNC) uses the network configuration and the opposite wireless network through the routing path established according to the connection identifier allocation plan assigned to use the same VPI / VCI between S-RNC and D-RNC. The controller (RNC) transmits a cell to the AIM port to which the controller (RNC) belongs while maintaining the same VPI / VCI of the input cell at the time of output.

First, in the link matching unit (LIM) -N resource management processing unit in the wireless network controller (including S-RNC, D-RNC, and G-RNC), the available VPI / VCI range for each radio network controller (RNC) accessible to the link matching unit (LIM) -N resource management processing unit. When the handover occurs between the RNCs, a connection is dynamically established by selecting an available connection identifier among VPIs / VCIs belonging to the RNCs according to the ALCAP processing procedure (601). Thereafter, the radio network controller (RNC) sets the No.7 signaling message path for transmitting the RNSAP and ALCAP messages according to the negotiated VPI / VCI, and the operation management message path to the remote operation and maintenance system (R-OMS). (602).

Then, G-RNC (Global RNC) is the IPC message path between the switch control processor (SCP) and all ATM matching units (ACP), the switch control processor (SCP), which must be set in advance to perform the connection control function of the ATM switch. The load path between the OMP and the operation and maintenance processor (OMP), the IPC message path between the switch control processor (SCP) and the access path processor (ARP), and the load path between the access path processor (ARP) and the operation and maintenance processor (OMP) As in the radio network controller (RNC), it is set to an initially determined default value in the ATM matching unit (AIM) and is ready for processing a connection control request from an application (603).

In addition, the link matching unit (LIM) -N in the G-RNC (Global RNC) does not need the AAL2 / AAL5 conversion function and performs only the connection function between the radio network controller (RNC) and the G-RNC (Global RNC). The header conversion is not performed and the default mode for bypassing the cell is set to bypass (604). In other words, G-RNC (Global RNC) does not need the link matching unit (LIM) -N function to perform AAL2 / AAL5 conversion function, but the unique UTOPIA between the radio access system (RAS) and the ATM matching unit (AIM) : Because it is connected by Universal Test Operation Physical Interface for ATM (Bus) bus, link between ATM matching unit (AIM) of G-RNC (Global RNC) and radio network controller (RNC) cannot be connected with universal STM1 interface. It is not economical because it is connected through N. In the future, it is desirable that the general purpose ATM link connection be easily changed or replaced with a commercial ATM switch that provides a general purpose interface. ATM connection for all VPI / VCI that can transmit / receive user traffic during handover, No.7 signaling message delivery path such as ALCAP and RNSAP, and operation management message delivery path to remote operation and maintenance system (R-OMS) G-RNC (Global) by setting both the path for transmitting and receiving control messages between the operation and maintenance processor (OMP) for diagnosis and status management of the link matching unit (LIM) -N and the self loopback test path at the initial operation of the system. RNC) completes the connection establishment function (605).

Therefore, G-RNC (Global RNC) is a soft handover traffic of the user between the radio network controller (RNC), No.7 signal message for handling the handover, all radio network controller (RNC) configured in the radio access network (RAN) And a remote operation management message through a remote operation and maintenance system (R-OMS) and a control message between processors inside the G-RNC system are enabled (606).

If a mobile communication service request is generated from the UE through the S-RNC (Serving RNC) before the handover is performed, the UE, the radio transceiver system (RTS), the S-RNC (Serving RNC), The CN / GPRS interwork with each other, establishes a general connection between mobile subscribers or between a mobile subscriber and a general subscriber (607), and enables cell transmission through a connection in a S-RNC (Serving RNC) (608).

In step 609, a request for measurement of a radio channel as a soft handover processing procedure that occurs as a mobile subscriber moves to another radio network controller (RNC) during a call, the terminal UE is adjacent to a base station (i.e., a radio transceiver system (RTS)). Receiving the magnitude of the pilot signal transmitted from the receiver), determining the pilot signal of each neighboring base station, and classifying and managing the pilot signal into the active pilot group and the candidate pilot group, and the radio network controller (RNC) reports the time or period of measurement information. Send a measurement control message to control the terminal (UE).

In the information transmission step 610 of the radio channel, when the measurement result is reported, the terminal UE reports information related to the measured value of the received signal strength in the connected sector to the radio network controller (RNC).

In addition, in step 611 of determining and determining the type of handover, the call control processor of the control station (that is, the radio network controller (RNC)) that has received the status of the radio channel may consider a new radio resource that is previously connected. The wireless link must be set up. That is, the handover decision determines when the UE (UE) will handover based on the information collected during the measurement period and where the base station can receive the best service, and these criteria are determined by various network managers. Controlled by parameters, the condition that handover occurs due to the movement of the terminal consists of the electric field strength of the received signal, the bit error rate, the distance between the UE and the base station, the service radius of the base station, and the traffic load adjustment on the network. do. The handover is divided into softer handover, sector handover, soft handover between adjacent base stations, and hard period of exchange. In the present invention, the soft handover between RNCs is used. This is a case where handover between RNCs is determined.

Soft handovers caused by movement to a radio transceiver system (RTS) of another radio network controller (RNC) connected to the Iur interface result in a branch addition and addition of a new radio transceiver system (RTS). Function is required Since the connection between the radio network controllers (RNC) is made through G-RNC (Global RNC), the radio network controller (RNC) establishes a connection dynamically according to the handover occurrence, and the information in advance in the G-RNC (Global RNC) Since the path to be forwarded is set, no additional connection establishment process is required when a handover occurs.

The soft handover connection branch addition function is performed when the terminal UE enters a radio transceiver system (RTS) in a new radio network controller (RNC), and a new radio transceiver system (RTS) received from the terminal UE. Is required to add a new radio transceiver system (RTS) between the radio network controllers (RNCs) based on the reported information, when the information is transmitted to the radio network controllers (RNCs). This is the procedure for establishing a new connection.

In S-RNC (Serving RNC), it adds a connection branch connected to G-RNC (Global RNC) (612), and since the new wireless transceiver system (RTS) is controlled by D-RNC (Drift RNC), RNSAP of Iur interface Requests for connection establishment included in the range of connection identifiers available for handover between a neighboring radio network controller (RNC) previously negotiated by an ALCAP to a Drift RNC (D-RNC) (613). On the other hand, in the D-RNC (Drift RNC) that receives the new connection establishment request by the signaling protocol, the connection negotiated by the signaling protocol between the wireless transceiver system (RTS) and the serving RNC (S-RNC) to which the mobile subscriber is connected is connected. The connection between the G-RNC (Global RNC) is established using the identifier (614), and the D-RNC (Drift RNC) notifies the completion of the handover connection branch setting to the Serving RNC (S-RNC) (615).

Accordingly, the D-RNC (Drift RNC) and the G-RNC (Global RNC) connection 616, which is the call path with the new base station to which the subscriber has moved, and the call path with the previous base station are simultaneously connected, and the S-RNC (Serving RNC) is connected. In step 617, the selector in the traffic control unit exchanges data stably using both radio channels connected to the UE and selects and transmits a cell having excellent quality of service (617).

In the meantime, the soft handover connection branch deletion function is a function of releasing the existing wireless transceiver system (RTS) by the user completely entering the new wireless transceiver system (RTS), and receiving the reported information of the existing wireless transceiver system (RTS). The network controller (RNC) determines the disconnection with the existing wireless transceiver system (RTS) and performs the release procedure (618).

In this case, the connection with the existing wireless transceiver system (RTS) is released between the terminal (UE) and the wireless transceiver system (RTS), and the wireless transceiver to terminate the wireless transceiver system (RTS) under the supervision of the radio network controller (RNC). A message containing information about the system (RTS) is transmitted to inform the completion of the soft handover. In the wireless transceiver system (RTS), the handover is completed by notifying the UE to the sector to be released (619). The path that was associated with the base station is released and the previously established CN / GPRS path of the Serving RNC (S-RNC) through the Global RNC (D-RNC) from the D-RNC (Drift RNC) to which the newly moved subscriber is connected. Soft handovered traffic between the radio network controllers (RNC) is transmitted through 620.

Subsequently, when the subscriber releases, the S-RNC (Serving RNC) recovers all the resources associated with the established connection (621) and notifies the Drift RNC (D-RNC) that the subscriber is released, which is set in the Drift RNC (D-RNC). It also disconnects and recovers all resources associated with it (622). According to the mobile call setup and release request, the S-RNC (Serving RNC) and D-RNC (Drift RNC) dynamically control the connection, while the G-RNC (Global RNC) maintains the connection established at the initial system. To provide.

According to the present invention as described above, when the RNC handover occurs, the RNC processes the RNSAP and ALCAP message through the No.7 signaling to dynamically establish the SVC connection, G-RNC in the PVC scheme of the VC switching function previously developed By setting the expected handover path between RNCs in advance, signal information and traffic data from the RNC are transferred to the other RNC as it is through the ATM layer without performing a signaling function when a handover occurs. Accordingly, in case of soft handover between RNCs connected to G-RNC, it provides high-speed soft handover function by reducing connection setup time by signaling in wired section, and reduces development cost by minimizing the development of additional functions. Serve in time.

In addition, when the RNC handover is performed using the G-RNC, the path extension method is applied, so even if the SNC connection establishment between the RNCs is started at the time when the handover is required, the cell transmission through the previously established path is continued, thereby simplifying the service. Continuity of is guaranteed.

In addition, by establishing a wide area RAN using G-RNC, it is possible to expand the scope of soft handover service, increase resource efficiency, improve simplified network configuration and management, and flexibly cope with RNC expansion or change. It is easy to build network and provides interconnection function between various RAN products supporting Iur interface through G-RNC.

In addition, although the present invention proposes a G-RNC that is operated by recycling previously developed RNC hardware and virtual channel switching software, it can be replaced with an ATM switching system that provides a universal link connection interface and a PVC function. It is obvious that the present invention can be applied to a RAN for providing a wider soft handover service in a communication network.

The method of the present invention as described above may be implemented as a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

According to the present invention as described above, in soft handover between RNCs, the RNC sets up the SVC connection and the G-RNC sets up the PVC connection in advance, thereby reducing the connection setup time by signaling in the RNC and G-RNC wired sections. It provides soft handover function and RAN using G-RNC to increase soft handover service capability and resource efficiency, and to simplify and simplify network configuration and management. It works.

Claims (8)

In the soft handover path control method in a radio access network (RAN), In case of handover between Radio Network Controllers (RNCs), a Virtual Channel (SVC) dynamically switched by processing Radio Network Subsystem Application Unit (RNSAP) and Access Link Control Application Protocol (ALCAP) messages between common RNCs through common line signaling. A first step of establishing a connection; And The second step of transmitting signal information and traffic data from the RNC to other RNCs as they are through a preset permanent virtual channel (PVC) connection without performing a signaling function in a G-RNC (Global RNC). Soft handover path control method in a wireless access network comprising a. The method of claim 1, The G-RNC, Performs an asynchronous transfer mode (ATM) switching function that performs a role of an upper layer interconnecting up to 12 RNCs, the RNC uses the SVC connection control method when setting the soft handover path between the RNC, the G- The RNC sets four PVCs as traffic transmission paths to satisfy the handover traffic capacity between the RNCs, thereby reducing the connection establishment time by signaling between the RNC and the G-RNC wired interval. Soft Handover Path Control Method The method according to claim 1 or 2, The first step is, In case of handover between adjacent RNCs, the RNSAP and the access link control application (ALCAP) messages are processed through No. 7 signaling, thereby preconfiguring virtual path identifiers / virtualities in the G-RNC for each RNC. A method for controlling soft handover paths in a wireless access network, comprising establishing a virtually switched virtual channel (SVC) connection within a channel identifier (VPI / VCI) range. The method of claim 3, wherein The second step, Signaling and traffic data from the RNC are transferred to the other RNC as it is through the preset ATM path without performing signaling processing in the G-RNC, thereby reducing service delay time due to signaling processing during handover in the G-RNC. A soft handover path control method in a wireless access network, characterized in that for reducing. In the soft handover path control method in a radio access network (RAN), A first step of negotiating a connection identifier to be used between a radio network controller (RNC) and a global RNC (G-RNC) in the radio access network (RAN), and establishing a system-specific control message path to be initially set up; Setting a path to be used for soft handover between RNCs connected in the G-RNC and a control message path in the G-RNC; A third step of establishing a connection in a serving RNC (S-RNC) according to the call setup request of the mobile subscriber; A fourth step of adding a connection branch from the S-RNC to the G-RNC when the soft handover occurs between the RNCs according to a result of handover measurement and determination processing according to the subscriber's movement to another RNC; A fifth step of selecting and delivering a cell of good quality among traffic received from the S-RNC and the D-RNC for a predetermined period in a D-RNC according to a connection branch; According to the processing result according to the connection branch deletion determination, the S-RNC releases the path connected to the previous base station, and the S-RNC is transmitted through the G-RNC from the D-RNC to which the newly moved subscriber is connected. A sixth step of uninterrupted transmission of the handovered traffic between RNCs through a path to a previously established network (CN / GPRS) of; And A seventh step of recovering all wired and wireless resources allocated to the S-RNC and the D-RNC according to the call release of the mobile subscriber; Soft handover path control method in a wireless access network comprising a. The method of claim 5, When a handover occurs between the RNCs, a neighboring RNC may process a Radio Network Subsystem Application Unit (RNSAP) and an Access Link Control Application Protocol (ALCAP) message through common line signaling to establish a dynamically switched virtual channel (SVC) connection. In the G-RNC, a soft handover path in a wireless access network is transmitted to another RNC without signal signaling function through a predetermined permanent virtual channel (PVC) connection. Control method. The method according to claim 5 or 6, The G-RNC, Performs an asynchronous transfer mode (ATM) switching function that performs a role of an upper layer interconnecting up to 12 RNCs, the RNC uses the SVC connection control method when setting the soft handover path between the RNC, the G- The RNC sets four PVCs as traffic transmission paths to satisfy the handover traffic capacity between the RNCs, thereby reducing the connection establishment time by signaling between the RNC and the G-RNC wired interval. Soft Handover Path Control Method In a radio access network (RAN) with a processor, for soft handover path control, A first function of negotiating a connection identifier to be used between a radio network controller (RNC) and a global RNC (G-RNC) in the radio access network (RAN), and setting a system-specific control message path to be initially set up; A second function of setting a path to be used for soft handover between RNCs connected in the G-RNC and a control message path in the G-RNC; A third function of establishing a connection in a serving RNC (S-RNC) according to a call setup request of a mobile subscriber; A fourth function of adding a connection branch from the S-RNC to the G-RNC when a soft handover occurs between the RNCs according to a result of handover measurement and determination processing according to a subscriber's movement to another RNC; A fifth function of selecting and delivering a cell of good quality among traffic received from the S-RNC and the D-RNC for a predetermined period in a D-RNC (Drift RNC) according to the addition of a connection branch; According to the processing result according to the connection branch deletion determination, the S-RNC releases the path connected to the previous base station, and the S-RNC is transmitted through the G-RNC from the D-RNC to which the newly moved subscriber is connected. A sixth function for uninterrupted transmission of the handovered traffic between RNCs over a path to a previously established network (CN / GPRS) of; And A seventh function of recovering all wired and wireless resources allocated to the S-RNC and the D-RNC according to the call release of the mobile subscriber; A computer-readable recording medium having recorded thereon a program for realizing this.