KR100561664B1 - How to Measure Call Quality in BCMC System - Google Patents

Abstract

In this paper, we propose a call quality measurement method considering the actual loss and interference between base station and wireless terminal in WCDMA system.

The method of measuring call quality may include receiving pilot channel information and broadcast channel information from a wireless terminal, extracting radio environment factors including base station transmission power, path loss, and uplink interference amount from pilot channel information and broadcast channel information; Determining that a signal processing failure occurs due to an instantaneous failure of the base station signal amplifier between the base station and the wireless terminal when the fluctuation range of the base station transmit power is greater than or equal to the first reference value, and the amount of uplink interference is greater than the second reference value or the fluctuation range of the uplink interference is reduced. Determining that signal processing defect has occurred between base station and wireless terminal by external repeater or noise in case of more than 3 reference value and signal processing failure between base station and wireless terminal by communication shadow area when path loss fluctuation is more than 4th reference value. Including determining that Thus, according to such a call quality measuring apparatus, it is possible to accurately determine the cause of signal processing failure by measuring the call quality of the wireless section in consideration of factors directly affecting the call quality.

WCDMA, Call Quality

Description

How to measure call quality in BCDM system {Method for Diagnosis of Call Quality in WCDMA System}

1 is a view for explaining an application example of the call quality measurement apparatus according to the present invention;

2 is a detailed configuration diagram of the call quality measurement apparatus shown in FIG.

3 is a flowchart illustrating a path loss measuring method between a base station and a wireless terminal in a call quality measuring apparatus according to the present invention;

4 is a flowchart for explaining a method of determining a cause of signal processing failure according to the present invention;

5A to 5C are exemplary diagrams of graphs showing call quality measurement results according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: wireless terminal 20: base station

30: wireless communication system 40: GPS antenna

50: wireless network management system 500: cell database

402: GPS receiver 404: radio environment factor analysis unit

406: call quality determination unit 408: display unit

410: control unit

The present invention relates to an apparatus and method for measuring performance of a wireless communication network, and more particularly, to an apparatus and method for measuring call quality in consideration of actual loss and interference between a base station and a wireless terminal in a WCDMA system.

The wireless communication system subdivides the area providing the wireless communication service into cell units and installs a base station in charge of wireless communication service for each subdivided cell. Means to provide a system. In such a wireless communication system, it is necessary to measure a call quality between a base station and a wireless terminal in order to maintain a desirable quality of service, thereby optimizing a call environment of a wireless communication network.

Conventionally, in order to measure the call quality between the base station and the wireless terminal, the wireless network has been optimized by analyzing the call quality only through signal processing and signal measurement transmitted and received by the terminal. Signal characteristics transmitted and received by the terminal include wireless terminal reception power (Rx Power), ratio of pilot channel signals (Ec / Io) among the signals received by the wireless terminal, wireless terminal transmission power (Tx Power), and terminal transmission sensitivity adjustment value (Tx). adjust).

However, the factors directly affecting the call quality in the WCDMA system are not limited thereto. On the downlink side, pathloss of radio waves according to distance, topography, buildings, etc. between the base station and the wireless terminal is included. In the case of receiving interference of the base station should be further considered.

However, in the conventional wireless communication system and call quality measuring apparatus, since these factors are not taken into consideration, there is a limit to efficiently optimizing the wireless network. have.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and in consideration of the radio environment factor added in the WCDMA system, the call quality measurement apparatus in the WCDMA system capable of optimizing the wireless communication system by measuring the call quality between the base station and the wireless terminal. And technical methods to provide the method.

The present invention for achieving the above-described technical problem is connected between a wireless terminal and a wireless communication system, a method of measuring the call quality between the base station of the cell in which the wireless terminal and the wireless terminal, pilot channel information and broadcasting from the wireless terminal Receiving channel information; Extracting radio environment factors including base station transmission power, path loss, and uplink interference amount from the pilot channel information and the broadcast channel information; Determining that a signal processing failure occurs due to an instantaneous failure of a base station signal amplifier between the base station and the wireless terminal when the variation range of the base station transmission power is equal to or greater than a first reference value; Determining that signal processing failure occurs between the base station and the wireless terminal due to an external repeater or noise inflow when the amount of uplink interference is greater than or equal to a second reference value or the variation of uplink interference is greater than or equal to a third reference value; And determining that a signal processing failure occurs between the base station and the wireless terminal by a communication shadow area when the path loss fluctuation range is greater than or equal to a fourth reference value.

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

1 is a view for explaining an application example of the call quality measurement apparatus according to the present invention.

As shown, the call quality measuring apparatus 40 of the present invention checks the position of the wireless terminal 10 using a GPS (Global Positioning System) antenna 400, and is connected to the wireless terminal 10 to connect the wireless terminal. The call quality is measured from the signals transmitted and received between the 10 and the base station 20. In addition, the call quality measuring device 40 is connected to the wireless network management system 50, the base station 20 receives the shape information of the base station to which the wireless terminal 10 belongs from the wireless network management system 50 And gains and losses occurring during signal transmission and reception between the wireless terminal 10 and the mobile terminal 10 can be accurately measured. The wireless network management system 50 is generally included in the wireless communication system 30.

On the other hand, the wireless terminal 10 may use the service provided by the wireless communication system 30 through the base station 20, the wireless network management system 50 is connected to the wireless communication system 30 is connected to the wireless communication system ( Receives shape information of each base station belonging to 30) and stores it in the cell database 500. The cell database 500 stores, for example, base station related information such as aerial gain according to an antenna pattern, feed line loss according to the type and length of a feed line, and the like.

The call quality measuring apparatus 40 extracts the actual path loss and the like by referring to the shape information associated with the base station from the cell database 500 as well as the signals transmitted and received between the wireless terminal 10 and the base station 20. In the system, it is possible to determine the coverage for each base station, that is, the area where transmission and reception are possible while maintaining good call quality.

FIG. 2 is a detailed configuration diagram of the call quality measuring apparatus shown in FIG. 1.

The call quality measuring apparatus 40 of the present invention includes a GPS receiver 402, a radio environment factor analyzing unit 404, a call quality determining unit 406, a display unit 408, and a controller 410.

The GPS receiver 402 receives location information (latitude and longitude information) of the measurement target wireless terminal 10 from a GPS satellite (not shown) through the GPS antenna 400.

The radio environment factor analysis unit 404 may include: Rx power, ratio of pilot channel signals (Ec / Io), transmission power (Tx Power), and terminal transmission sensitivity adjustment value (Tx) among signals received by the wireless terminal 10. In addition to basic radio environment factors such as adjust, it receives or measures CPICH Common Pilot Channel Received Signal Code Power (RSCP), Primary CPICH Tx POWER, Pathloss, Uplink Interference, etc. The cell database 500 of the network management system 50 requests the feeder loss value, the aerial gain value, and the like of the base station.

Here, the base station transmission power and uplink interference amount are values that the wireless terminal 10 receives from the wireless terminal 10 a system information message received from the base station. In addition, CPICH RSCP is measured directly at the wireless terminal 10.

The call quality determining unit 406 simultaneously identifies the environment and base station state of a wireless section, which is a communication path between the wireless terminal 10 and the base station 20, from the wireless environment factor received or measured by the wireless environment factor analyzer 404. In case that a signal processing failure occurs in the wireless terminal 10, the reason for the failure, for example, a weak base station transmission power, an excessive path loss, an excessive uplink interference, and the like can be diagnosed accurately. 30 can optimize the environment of the wireless section.

The display unit 408 displays radio environment factors such as base station transmission power, uplink interference, and path loss received or measured by the radio environment factor analyzer 404 in a graph so that the call quality measurer can determine the environment of the radio section to be measured. Make sure you understand the situation.

3 is a flowchart illustrating a method for measuring a path loss between a base station and a wireless terminal in the apparatus for measuring call quality according to the present invention.

The path loss of the wireless terminal 10 and the base station 20 in the wireless section of the WCDMA system is represented by [Equation 1].

Pathloss = base station transmit power (P-CPICH Tx Power)-CPICH RSCP

However, the path loss calculated in [Equation 1] is merely a calculated value, and is not an actual path loss in consideration of aerial gains such as feeder loss and antenna pattern according to feeder type and length. Therefore, the feeder loss value and the aerial gain value should be considered to extract the actual path loss.

That is, the radio environment factor analysis unit 404 of the call quality measuring device 40 first receives from the base station 20 to the wireless terminal 10 to extract the path loss, which is an element on the downlink, which affects the call quality. The received CPICH is received from the wireless terminal 10 (S101), and the base station transmission output is extracted therefrom (S102). Thereafter, the received signal code power CPICH SRCP of the wireless terminal 10 is extracted from the wireless terminal 10 (S103), and the shape of the base station 20 from the cell database 500 of the wireless network management system 50. Information, that is, the aerial gain value and the feeder loss value are received (S104).

Next, an actual path loss is extracted as shown in [Equation 2] using the values received or measured in step S101 to step S104 (S105).

Pathloss = Base Station P-CPICH Tx Power + Aerial Gain + Feedline Loss-CPICH RSCP

By extracting the actual path loss in consideration of the shape information of the base station as shown in [Equation 2], it is possible to determine the area that can be transmitted and received while maintaining a good call quality in the wireless communication system.

4 is a flowchart illustrating a call quality measuring method according to the present invention.

First, the radio environment factor analysis unit 404 receives CPICH information from the wireless terminal 10 (S201), and receives broadcast channel (BCH) information from the wireless terminal 10 (S202). Radio environment factors including base station transmit power, path loss as shown in Equation 2, and uplink interference amount are extracted.

Thereafter, the call quality determining unit 406 checks whether the transmission output fluctuation range of the base station among the extracted wireless environment factors is a first reference value, for example, 10 dB or more (S203). It is determined that the instantaneous failure of the amplifier (S204). If the transmission output fluctuation range of the base station is 10 dB or less, it is checked whether the amount of uplink interference is a second reference value, for example, -75 dBm or more, or whether the variation in uplink interference is a third reference value, for example, 10 dB or more (S205). If the amount of uplink interference is more than -75dBm or the fluctuation range of the uplink interference is more than 10dB, it is determined that the cause of signal processing failure is due to an external repeater or noise inflow (S206).

On the other hand, if the amount of uplink interference is not more than -75dBm or the variation of uplink interference is not more than 10dB, it is checked whether the pathloss fluctuation is the fourth reference value, for example, 10dB or more (S207), and the pathloss fluctuation is 10dB. In the case of abnormality, it is determined that a poor signal processing occurs due to the shaded area caused by the building (S208). In addition, if there is no problem in the base station transmission power, uplink interference and path loss, it is determined that the signal processing state is good (S209). Here, the first to fourth reference values are values that can be changed according to the characteristics of the wireless section and the characteristics of the wireless communication system.

5A to 5C are exemplary diagrams of a graph showing a call quality measurement result according to the present invention. FIG. 5A shows a change in base station transmission power measured by the call quality measuring device 40 according to the present invention. 5C shows the change in path loss. The call quality measurer can visually check the graph and grasp the situation of the wireless environment between the base station 20 and the wireless terminal 10 in detail.

As such, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not as restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

As described above, according to the present invention, the signal quality is measured by measuring the call quality of the wireless section in consideration of the propagation path loss between the base station and the terminal, the terrain, the building, and the amount of interference received from the base station, which are factors directly affecting the call quality. The cause of the poor processing can be pinpointed.

Claims (8)

delete delete delete delete A method of measuring call quality between a base station of a cell in which the wireless terminal exists and the wireless terminal connected between a wireless terminal and a wireless communication system, Receiving pilot channel information and broadcast channel information from the wireless terminal; Extracting radio environment factors including base station transmission power, path loss, and uplink interference amount from the pilot channel information and the broadcast channel information; Determining that a signal processing failure occurs due to an instantaneous failure of a base station signal amplifier between the base station and the wireless terminal when the variation range of the base station transmission power is equal to or greater than a first reference value; Determining that signal processing failure occurs between the base station and the wireless terminal due to an external repeater or noise inflow when the amount of uplink interference is greater than or equal to a second reference value or the variation of uplink interference is greater than or equal to a third reference value; And Determining that signal processing failure occurs between the base station and the wireless terminal due to a communication shadow area when the path loss fluctuation range is greater than or equal to a fourth reference value; Call quality measurement method in a WCDMA system comprising a. The method of claim 5, The method for measuring the path loss Receiving pilot channel information received from the measurement target base station to the wireless terminal from the wireless terminal; Extracting a base station transmit power from the pilot channel information; Extracting received signal code power of the wireless terminal from the measurement target wireless terminal; Receiving shape information of the base station from the wireless communication system; And Extracting a path loss by referring to the base station transmission power, the wireless terminal received signal code power, and base station shape information; Call quality measurement method in a WCDMA system comprising a. The method of claim 6, The path loss is A method of measuring call quality in a WCDMA system extracted by [P-CPICH Tx Power + Aerial Gain + Feeder Loss-CPICH RSCP]. The method of claim 5, The first reference value is 10 dB, the second reference value is -75 dBm, the third reference value is 10 dB, and the fourth reference value is 10 dB.

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