KR20020064814A - Apparatus and method for call simulating in cellular mobile telecommunication system - Google Patents

Abstract

PURPOSE: A call simulation apparatus and method for a cellular mobile communication system is provided to test outgoing and incoming calls of a base station system and test an interface matching between the base station system and an MSC(Mobile Switching System). CONSTITUTION: A trunk matching board(73) connects to a BSC(Base Station Controller)(30) through a trunk. A main control board(71) connects to the BSC(30) through the trunk matching board(73), and is operated as a virtual base station for simulating the origination and termination operation of a virtual call and providing the virtual call to a cellular mobile communication system.

Description

Apparatus and method for call simulation of cellular mobile communication system {APPARATUS AND METHOD FOR CALL SIMULATING IN CELLULAR MOBILE TELECOMMUNICATION SYSTEM}

The present invention relates to a cellular mobile communication system, and more particularly, to an apparatus and method for performing call simulation in a base station system.

FIG. 1 is a block diagram of a conventional cellular base station system. Referring to FIG. 1, a base transceiver subsystem (BTS) 20 includes a radio unit 21, a digital unit 23, and a main processor 25. The base station controllers (BSCs) 30 are configured to connect and communicate with a wireless channel with the mobile communication terminal 10 in each cell. The base station controllers (TSCs) 30 perform voice compression and handoff control. and Selector Bank (31) and Call Control Processor (CCP) 33 to control the base station 20, the Mobile Switching Center (MSC) 40 is a home location register (50) The subscriber information is obtained from the subscriber station and the mobile subscriber is connected to another subscriber system. Base station 20 and base station controller 30 are managed and maintained by base station management system 60.

The mobile communication system configured as described above includes a simulation device for checking whether or not normal service can be provided. 2 shows a block diagram of a simulation apparatus according to the prior art, the base station controller 30 includes a base station controller simulator 35 interworking with the call control processor 33, and the mobile switching center 40 is a main control. And a mobile switching center simulator (43) in conjunction with a Central Control Subsystem (CCS) 41. The base station controller simulator 35 may be implemented as a separate processor or a software block loaded and operated in the TSB 31 as shown in the figure. The base station controller simulator 35 may communicate with the mobile switching center simulator 43 and various processors through the call control processor 33. Exchange Inter-Processor Communication (IPC) messages.

3 is a message flow diagram illustrating a simulation operation according to the prior art.

Referring to FIG. 3, when the base station controller simulator 35 generates an origination message and transmits it to the call control processor 33, the call control processor 33 performs a known originating call connection procedure between the base station controller and the mobile switching center. The following messages are exchanged with the mobile switching center simulator 43 to establish a connection and send an origination acknowledgment message to the base station controller simulator 35. Then, the base station controller simulator 35 sets up an outgoing call by exchanging messages according to a known originating call connection procedure between the base station and the base station controller with the call control processor 33.

When performing the handoff test, when the base station controller simulator 35 sends a handoff request message to the call control processor 33, the call control processor 33 sends a request to the base station controller simulator 35 instead of requesting channel allocation to the base station. Requires channel assignment.

As such, since the base station controller simulator 35 is designed to include the functions of the base station, the base station controller simulator 35 can perform only a call setup function simulation by a simple control signal excluding traffic. Therefore, it was not possible to measure the amount of load actually generated by the call connection at the base station or the base station controller and to test the traffic packet processing function.

In addition, to test the performance of the call control processor, a mobile switching center simulator capable of performing mobile switching station routing and paging requirements for outgoing signals is required. Therefore, a mobile switching center simulator that can be adapted to the structure of the base station controller simulator and the mobile switching center is developed. There was a problem that had to be.

Accordingly, an object of the present invention, which was devised to solve the problems of the prior art operating as described above, is to provide an apparatus and method for call simulation of a cellular mobile communication system.

Another object of the present invention is to provide a call simulation apparatus and method capable of performing a test for originating and incoming calls of a base station system and a test for interface matching between a base station system and a mobile switching center.

Embodiments of the present invention devised to achieve the object described above are linked to a cellular mobile communication system including at least one base station controller controlling a base station and a mobile switching center connecting the base station controller to another subscriber system. In the call simulation device,

A relay line matching board connected to the base station controller through a relay line;

And a main control board connected to the base station controller through the relay line matching board and operating as a virtual base station to simulate the origination and incoming operation of the virtual call to apply the virtual call to the cellular mobile communication system.

Another embodiment of the present invention provides a call simulation method of a cellular mobile communication system including at least one base station controller for controlling a base station and a mobile switching station for connecting the base station controller to another subscriber system.

Connecting a base station simulator to a mobile switching center via a base station controller, operating as a virtual base station, the base station simulator simulating originating and terminating operations of a virtual call or originating operation of a virtual call;

Inputting call simulation information into the base station simulator;

Making a virtual call by using the input call simulation information in the base station simulator and establishing a call origination path with the mobile switching center through the base station controller;

Establishing a call destination path with the mobile switching center through the base station controller in the base station simulator in response to a request of the mobile switching center.

Another embodiment of the present invention provides a call simulation method for a cellular mobile communication system including at least one base station, at least one base station controller controlling the base station, and a mobile switching center connecting the base station controller to another subscriber system. ,

Connecting a base station simulator to a mobile switching center via a base station controller, operating as a virtual base station, the base station simulator simulating originating and terminating operations of a virtual call or originating operation of a virtual call;

Inputting call simulation information into the base station simulator;

Establishing a call origination path with the mobile switching center through the base station controller by originating a virtual call using the input call simulation information in the base station simulator;

Establishing a call destination path with the mobile switching center at a receiving base station of the at least one base station in response to a request of the mobile switching center.

1 is a block diagram of a typical cellular base station system.

2 is a block diagram of a simulation apparatus according to the prior art.

3 is a message flow diagram showing a simulation operation according to the prior art.

4 is a block diagram of a simulation apparatus according to an embodiment of the present invention.

5 is a message flow diagram illustrating a call origination operation by a base station simulator in accordance with the present invention.

6 is a message flow diagram illustrating a call initiation operation to a base station simulator in accordance with the present invention.

7 is a message flow diagram illustrating a call initiation operation to another base station in accordance with the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. Like reference numerals are used to designate like elements even though they are shown in different drawings, and detailed descriptions of related well-known functions or configurations are not required to describe the present invention. If it is determined that it can be blurred, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

4 is a block diagram of a simulation apparatus according to an embodiment of the present invention. As illustrated, the base station simulator 70 is a relay line matching board 73 connected to the base station controller 30 through an E1 / T1 relay line. And a main control board 71 for performing a call simulation operation and controlled by a control computer 80 connected via an RS-232 serial cable. The base station simulator 70 generates a virtual call on behalf of the base station without a mobile communication terminal to generate a load on the base station controller 30 and the mobile switching center 40, thereby interface between the base station controller 30 and the mobile switching center 40. Allows you to check the A-interface function. Therefore, it can be matched to the base station controller 30 and the mobile switching center 40 manufactured by different manufacturers to measure its performance and reliability.

In response to the user command input through the user command window of the control computer 80, the base station simulator 70 is driven and the originating and incoming call operation of the virtual call by the test terminal is controlled and the statistical data is collected as a result. The control computer 80 also presets various conditions of the virtual call set in the base station simulator 70 (the unique number of the test terminal, the call setup period, etc.) in advance.

In another embodiment of the present invention, the base station simulator 70 is implemented as a simulation software block that is driven instead of a software block for call processing in the main processor 25 of the actual base station 30. That is, the main controller 25 downloads the simulation software block from the base station controller 30 instead of the software block for call processing of the base station when it is first powered on and starts up, and operates by the downloaded simulation software block. The base station thus operates as the base station simulator 70. Using this method, any base station already connected to a mobile communication system and having at least a relay line matching board and a main processor processor board can perform the test, and at the same time it is possible to perform the test on multiple base stations.

Base station simulator 70 may operate as a virtual base station in Digital Communications Service (DCS), Personal Communications Services (PCS), and Code Division Multiple Access (CDMA) V.III. The virtual call generated from the base station simulator 70 passes through the mobile communication network connecting the vocoder (ie, TSB) of the base station controller, the call control processor and the mobile switching center. In this process, a virtual traffic packet is transmitted. Performs an operation similar to when connecting a call.

The base station simulator 70 performs a main processor processor function of the base station and a channel element (CE) function of the digital unit to generate at least one virtual call through a relay line matching board to exchange traffic packets with the base station controller and the base station controller and Generate a load on the mobile switching center. Depending on the type of virtual call selected by the user, the call originated by the base station simulator 70 may be received by the mobile communication terminal tuned to another general base station or by the base station simulator 70.

The base station simulator 70 may set a call holding time according to call simulation information input in advance in processing the traffic packet on behalf of the traffic channel element. To test the Busy Hour Call Attempt (BHCA) performance of the base station controller, a large number of calls are continuously applied while the call is established and released. This is because the traffic packets for all calls cannot be processed if a large number of calls continue to be maintained.

In the following detailed description of the specific operation of the call simulation apparatus according to the present invention, it is assumed that the base station simulator is a base station operated by a call simulation software block.

The main processor of the base station on which the call simulation is to be performed operates as the base station simulator 70 by loading and installing the simulation software block from the base station controller. The control computer 80 may be configured as a personal computer (PC). The control computer 80 is connected to the base station simulator 70 under the control of a user and inputs information for call simulation to the base station simulator 70.

At this time, the control computer 80 first selects the type of the virtual call. The type of virtual call selects whether to call the virtual call to the base station simulator 70 or to another base station. Once the test type is selected, the call holding time is entered. It is not necessary to enter the call holding time because it is not necessary to send traffic if only the call access function by the control signal is to be tested. In addition, a call origination period of a call is input as information for sending a plurality of virtual calls. In addition, the number of virtual call originations or the total time to perform a test can be entered.

As described above, when the input of the call simulation information is completed, the control computer 80 may also use the unique information of at least one calling terminal or at least one called terminal, which will be used when the base station simulator 70 attempts to make or make a call. For example, enter a Mobile Identification Number (MIN) and an Electronic Serial Number (ESN). When the input is completed, the base station simulator 70 registers the input terminals to the home location register of the mobile switching center 40 under the control of the control computer 80. This is because the originating terminal and the terminating terminal must be normally authenticated at the mobile switching center 40 at the attempt of the call.

When all the pre-work as described above is completed, the base station simulator 70 starts the call simulation and proceeds with the incoming call and / or the outgoing call according to the input call simulation information. Messages generated during the call progress are continuously monitored in the message window of the control computer 80. The user can check the statistical data generated by the test through the message window.

Although the base station simulator 70 has been described as being controlled by the control computer 80, when the base station simulator 70 is implemented as a simulation software block installed in a base station that is actually operating, the user can access the base station through a debug port or remote access. By entering call simulation information and monitoring the output messages. In the case of a remote connection, the user can generate multiple virtual calls at multiple base stations at the same time.

As an example of the test performed by the base station simulator 70, a call test transmitted by the base station simulator 70 of the present invention and received by the base station simulator 70 will be described in detail as follows.

5 is a message flow diagram illustrating a call origination operation by a base station simulator in accordance with the present invention.

Referring to FIG. 5, the base station simulator generates an origination message and transmits it to the call control processor. At this time, the outgoing message includes unique information (telephone number or serial number) of the calling terminal and the called terminal stored in advance in the base station simulator. The calling terminal and the called terminal are pre-registered in the base station simulator.

The call control processor requests the authentication of the originating terminal by sending a Configuration Module Service Request message to the mobile switching center. If the terminal is not registered in the home location register, the mobile switching center rejects the authentication and the call fails. However, if the terminal is normally registered, the mobile switching center transmits a channel allocation request message to the call control processor, indicating that the calling terminal is authenticated. Accordingly, the call control processor responds with an origination acknowledgment message to the base station simulator.

The base station simulator generates a channel assignment message and delivers it to the call control processor. In the general call origination procedure, the base station receiving the originating acknowledgment message allocates a traffic channel to the originating terminal and delivers a channel assignment message including the address of the assigned traffic channel element to the base station controller. However, the channel assignment message generated by the base station simulator includes the address of the base station simulator instead of the address of the traffic channel element. This is because the base station simulator performs the function of the traffic channel element in the call originating simulation operation according to the present invention.

The call control processor determines the vocoder of the base station controller to be allocated to the calling terminal, that is, the processor and vocoder controlling the SVP (Selector and Vocoder Processor) and the messages according to the SVP and the known call origination procedure (Setup Cs Message, Call Config Req Cs , Call Config Cs). The SVP sends a Link Act message to the base station simulator instead of the traffic channel element and waits for an acknowledgment. The link activation message contains information on the type of traffic packet. The type of the traffic packet is 0 according to the most significant bit value of the frame type included in the link activation message, and traffic 1 is a traffic + control message. + control message) and if 2, it is set as control message only. The base station simulator transmits the link activation acknowledgment message to the SVP after a predetermined time, for example, 500 ms after receiving the link activation message. This link activation acknowledgment message is treated as a control signal.

After receiving the link activation acknowledgment message, the base station simulator functions as an originating terminal. That is, first, the base station simulator repeatedly transmits a terminal acquisition message to the SVP 10 times at a predetermined time, for example, 40 ms, for mobile acquisition. At this time, if the SVP does not normally receive the terminal acquisition message, a mobile acquisition acquisition (Mobile Not Acquisition Fail) will occur and the base station controller will check whether there is an error in the SVP.

If the SVP normally receives the terminal acquisition message even once, the SVP transmits a BS Ack Order to the base station simulator. The base station simulator transmits a terminal acknowledgment (MS Ack Order) to the SVP four times at a predetermined time, for example, 100 ms. The format of the terminal Ack command generated by the base station simulator is shown in Table 1 below.

field Length (bits) Message Type ['00000111] 8 ACK_SEQ 3 MSG_SEQ 3 ACK_SEQ One VALID_ACK One ADDR_TYPE 3 ADDR_LEN 4 ADDRESS 8 × ADDR_LEN ORDER 6 ADDR_RECORD_LEN 3 order-specific fields (if used) 8 × ADD_RECORD_LEN RESERVED 2

When the SVP receiving the terminal acknowledgment responds to the base station simulator with a service option negotiation message, the base station simulator transmits a service option connect complete message to the SVP. The format of the service option access complete message generated by the base station simulator is shown in Table 2 below.

field Length (bits) Message Type ['00001110] 8 ACK_SEQ 3 MSG_SEQ 3 ACK_SEQ One ENCRYPTION 2 SERV_CON_SEQ 4 RESERVED 2

When the call origination path is established by the operation as shown in Fig. 5, the base station controller informs the mobile switching center and the mobile switching center requests paging for call initiation to the base station simulator. This is because the called terminal is located in the base station simulator.

6 is a message flow diagram illustrating a call termination operation to a base station simulator according to the present invention.

Referring to FIG. 6, when the mobile switching center transmits a paging request message to the base station simulator through the call control processor, the base station simulator responds to the call control processor with a paging response message and call control. The processor sends a channel assignment request message to the base station simulator.

The base station simulator then generates a channel assignment message and delivers it to the call control processor. For the same reason as described in the call origination procedure, the channel assignment message includes the address of the base station simulator instead of the address of the traffic channel element assigned to the called terminal. The call control processor, SVP and base station simulator then establish a call forwarding path by exchanging messages similar to those in the call origination procedure.

Once the originating and terminating routes are established, the call connects and traffic packets are exchanged. At this time, the base station simulator generates a virtual 20ms traffic packet and transmits it continuously to maintain a call state. If the traffic packet is not normally received by SVP, the call will be dropped (DROP). The base station simulator repeatedly transmits the virtual traffic packet by the number of transmissions of the traffic packet set according to the call holding time. Traffic packets are analyzed and processed by the SVP and forwarded by the mobile switching center to the call destination path, i.e. base station simulator.

As another example of the test performed by the base station simulator, a call test transmitted by the base station simulator of the present invention and received by another base station will be described below.

The virtual call generated from the base station simulator is delivered to the actual mobile communication terminal tuned to another base station. The call origination procedure is as shown in FIG. In FIG. 5, the originating terminal is registered in advance in the base station simulator, but the called terminal is not registered in the base station simulator.

7 is a message flow diagram illustrating a call termination operation to another base station according to the present invention.

Referring to FIG. 7, when a mobile switching center (MSC) requests paging from a call control processor (CCP) and a main control processor (BCP) of a base station to which a terminating terminal is tuned through an SVP, the base station main processor is paging to a mobile communication terminal. After receiving the request and receiving the response, the call control processor responds with a paging response message, and the call control processor transmits a channel assignment request message to the base station main processor. The base station main processor then assigns traffic channel elements and transmits information on the assigned traffic channel elements to the terminal to establish a traffic path with the terminal. The procedure by which call forwarding routes are then established is commonly known.

Once the outgoing and incoming paths are established and the call is connected, the base station simulator exchanges the virtual traffic packets with the base station controller vocoder, or SVP, to maintain and release the call for a predetermined call duration, with a minimum of 20 seconds. It is preferable to set as above. In addition, the call generation period is preferably set to 60 ms (ie, 60000 BHCA) or more in order to prevent overload as the 20 ms long virtual traffic packet is generated and processed in the base station simulator.

The call origination path and the call initiation path are established and there is a load on the system during and after the call is connected. The system load can be measured in three ways as shown below.

The first method is to measure the load of the call control processor in the base station controller. After a large number of calls are applied in the base station simulator, the processor load of the call control processor may be periodically checked according to a predetermined cycle. As one example, the load of the processor may be determined as a percentage of processor idle time during the reference time.

As described above, in order to test the performance of the base station controller call control processor, it is not necessary to generate and transmit a traffic packet in the base station simulator after the call is connected. This is because the call control processor processes only control signals, not traffic packets. Therefore, in this case, the call is attempted according to a preset transmission period, and the control signal processing capability, that is, the load of the call control processor is measured by repeating the operation of releasing the call immediately after the call is connected. Therefore, the transmission cycle is properly adjusted to generate an appropriate BHCA load. Also, the load state of the base station controller can be known through the user message window of the base station management system.

The second method is to measure the vocoder's load. The TSB of the base station controller includes at least one Selector Interface Processor (SIP) and a plurality of SVPs, which are interfaced with the vocoder of the base station controller to control the status of the SVP controlling each vocoder. When generated, a substantial load is applied to the SIP because traffic packets are transmitted. The user can check the SIP load by executing a CLC (CPU Load Check) command through the debug port of the SIP.

The third method is to measure statistical data through the debug port of the base station main processor. By adjusting the generation cycle of the call according to the preset BHCA, the desired system load can be applied. Therefore, the optimal system load condition is derived by adjusting the call generation period. This is the same as the conventional load measurement method using the base station controller simulator.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible 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 defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention can measure the system load by exchanging similar traffic packets in a real wireless environment, and can transmit a call sent by a base station simulator to a mobile terminal tuned to another base station in normal operation for a predetermined time. Since the traffic can be automatically released after maintaining it, the effect similar to the site can be obtained. Thus, the present invention has the effect of early detection of problems that may occur in the field because it can measure the load of the system and ensure reliability even when interworking with other systems. In addition, the system load can be checked in advance by applying a virtual call to each base station without generating an actual call after the system is driven.

Claims (13)

A call simulation apparatus interoperating with a cellular mobile communication system including at least one base station controller for controlling a base station and a mobile switching center for connecting the base station controller to another subscriber system. A relay line matching board connected to the base station controller through a relay line; And a main control board connected to the base station controller through the relay line matching board and operating as a virtual base station to simulate the origination and incoming operation of the virtual call to apply the virtual call to the cellular mobile communication system. The call simulation apparatus according to claim 1, wherein the main control board generates a virtual traffic packet when the virtual call is established, and transmits the generated virtual traffic packet to the base station controller through the relay line matching board. 3. The call simulation apparatus according to claim 2, wherein the main control board analyzes and processes the virtual traffic packets received through the relay line matching board. A call simulation method of a cellular mobile communication system comprising at least one base station controller for controlling a base station and a mobile switching center connecting the base station controller to another subscriber system. Connecting a base station simulator to a mobile switching center via a base station controller, operating as a virtual base station, the base station simulator simulating originating and terminating operations of a virtual call or originating operation of a virtual call; Inputting call simulation information into the base station simulator; Making a virtual call by using the input call simulation information in the base station simulator and establishing a call origination path with the mobile switching center through the base station controller; And in response to a request from the mobile switching center, establishing a call destination path with the mobile switching center through the base station controller in the base station simulator. 5. The call simulation according to claim 4, further comprising the step of performing location registration of the calling terminal and the called terminal by using the unique number of the calling terminal and the called number of the called terminal in the base station simulator. Way. 6. The method of claim 4 or 5, further comprising: generating a virtual traffic packet in the base station simulator and transmitting it over the established call origination path; Receiving the virtual traffic packet through the established call destination path in the base station simulator. A call simulation method of a cellular mobile communication system including at least one base station, at least one base station controller controlling the base station, and a mobile switching station connecting the base station controller to another subscriber system. Connecting a base station simulator to a mobile switching center via a base station controller, operating as a virtual base station, the base station simulator simulating originating and terminating operations of a virtual call or originating operation of a virtual call; Inputting call simulation information into the base station simulator; Making a virtual call by using the input call simulation information in the base station simulator and establishing a call origination path with the mobile switching center through the base station controller; Establishing a call destination path with the mobile switching center at a destination base station of the at least one base station in response to a request of the mobile switching center. The call simulation method of claim 6, further comprising performing location registration of the calling terminal by using the unique number of the calling terminal in the base station simulator. 9. The method of claim 7 or 8, further comprising: generating a virtual traffic packet in the base station simulator and transmitting it over the established call origination path; Receiving the virtual traffic packet through the established call terminating path at the terminating base station. The call simulation method according to claim 4 or 7, wherein the call simulation information is a type of a virtual call, a calling cycle, a unique number of a calling terminal, and a unique number of a called terminal. 11. The method of claim 10, further comprising the step of establishing a call origination path periodically according to the originating period in the base station simulator and releasing the set call immediately after the virtual call is established. The call simulation method according to claim 6 or 9, wherein the call simulation information is a type of a virtual call, an originating period, a call holding time, a unique number of a calling terminal, and a unique number of a called terminal. 13. The method of claim 12, further comprising: in the base station simulator, establishing a call origination path periodically according to the originating period, establishing a virtual call, and releasing the set call after the call holding time elapses. Simulation method.