JP2016076872A - Call-out analysis device, call-out analysis method, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contribute to the determination of a failure cause of call-out for a base station device to call out a terminal device in a radio communication system.SOLUTION: A call-out analysis device 1 analyzes call-out from a base station device to call out a terminal device in a radio communication system. The call-out analysis device comprises: an input unit 11 for inputting a control signal exchanged by a base station control device that controls the base station device; and a call-out failure cause determination unit 16 for determining a failure cause of the call-out on the basis of a control signal to call out the terminal device and a control signal of a call-out response from the terminal device, and a time-out time of each call out estimated by a time-out time estimation unit 15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a call analysis device, a call analysis method, and a computer program.

  Conventionally, in a wireless communication network using a network function of “Evolved Packet Core: EPC” (see Non-Patent Document 1), an MME (Mobility Management Entity) receives an incoming message (Downlink Data) from an S-GW (Serving Gateway). In response to the Notification Acknowledgment, a call message (Paging) for calling a UE (User Equipment) is transmitted to the eNB (eNodeB). If the MME does not receive a response message (Initial UE Message) for notifying a response from the UE to the call message from the eNB and determines that the call has failed, the MME sends an incoming call failure message (Downlink Data Notification Failure Indication) to the S-GW. Send. As a conventional analysis method for call failure, the call success rate and failure rate are calculated.

3GPP TS23.401 (V12.0.0), “General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access”

  The success / failure status of a call is important information for the communication carrier in order to improve the quality of the communication service. For this reason, it is preferable to know the cause of the call failure in addition to the call success rate and failure rate.

  The present invention has been made in view of such circumstances, and provides a call analysis device, a call analysis method, and a computer program that can contribute to determination of the cause of failure of a call for calling a terminal device from a base station device in a wireless communication system. The issue is to provide.

(1) One aspect of the present invention is a call analysis device that analyzes a call for calling a terminal device from a base station device in a wireless communication system, and a control signal exchanged by a base station control device that controls the base station device An input unit for inputting, a call time measuring unit for measuring a call time in the case of an incoming call failure based on a control signal for notifying an incoming call and a control signal for notifying an incoming call failure among the input control signals, The number of calls for calling the terminal device based on the control signal for calling the terminal device among the input control signals, the control signal for the call response from the terminal device, and the call time measured by the call time measuring unit A number-of-calls estimation unit for estimating an upper limit value of the control signal, a control signal for calling the terminal device among the input control signals, and a call response from the terminal device On the basis of the control signal, the call time measured by the call time measurement unit, and the upper limit value of the call number estimated by the call number estimation unit, A time-out time estimation unit that estimates a certain time-out time for each call for calling the terminal device, a control signal for calling the terminal device among the input control signals, and a control signal for a call response from the terminal device, A call analysis apparatus comprising: a call failure cause determination unit that determines a cause of failure of the call based on a timeout time of each call that is estimated by the timeout time estimation unit.
(2) One aspect of the present invention is a call analysis device that analyzes a call for calling a terminal device from a base station device in a wireless communication system, and a control signal exchanged by a base station control device that controls the base station device And an input unit for inputting a timeout time that is an upper limit value of a waiting time until the terminal device is called and that calls each terminal device, and the input control signal among the input control signals. A call failure cause determination unit for determining a cause of failure of the call based on a control signal for calling a terminal device, a control signal for a call response from the terminal device, and a time-out time of each input call A call analysis device provided.
(3) According to one aspect of the present invention, in the call analysis device according to any one of (1) and (2), the call failure cause determination unit is configured to determine a previous failed call among events in which the call is successful. A call analysis device that determines that the cause of the failure is a movement of the terminal device for a successful call event outside the call area.
(4) According to one aspect of the present invention, in the call analysis device according to any one of (1) to (3), the call failure cause determination unit includes a previous failed call among events in which the call is successful. A call analysis device that determines that the cause of the failure is a factor of the base station device for a successful call event in the same call area.
(5) According to one aspect of the present invention, in the call analysis device according to any one of (1) to (4), the call failure cause determination unit does not respond to a call even after waiting for the total time-out time of each call. A call analysis device that determines that the cause of the failure with no response is out of range of the terminal device.

(6) One aspect of the present invention is a call analysis method for analyzing a call for calling a terminal device from a base station apparatus in a wireless communication system, and the call analysis apparatus controls the base station apparatus. An input step of inputting a control signal to be exchanged, and a call in the case of an incoming call failure based on a control signal for notifying an incoming call and a control signal for notifying an incoming call failure, of the input control signal. A call time measuring step for measuring time; a control signal for calling the terminal device among the inputted control signals; a control signal for a call response from the terminal device; and the call time measuring step. A number-of-calls estimation step for estimating an upper limit value of the number of calls for calling the terminal device based on the measured call time; A control signal for calling the terminal device and a control signal for a call response from the terminal device, a call time measured by the call time measurement step, and a call frequency estimation step. Based on the estimated upper limit value of the number of calls, a time-out time estimation step for estimating a time-out time, which is an upper limit value of a waiting time until the terminal device is called, for each call of calling the terminal device, and the call Based on the control signal for calling the terminal device among the input control signals, the control signal for the call response from the terminal device, and the time-out time of each call estimated by the time-out time estimation step. And a call failure cause determination step for determining a cause of failure of the call. It is.
(7) One aspect of the present invention is a call analysis method for analyzing a call for calling a terminal device from a base station device in a wireless communication system, and the call analysis device controls the base station device. An input step for inputting a control signal to be exchanged and a timeout time that is an upper limit of a waiting time until the terminal device is called, and a timeout time of each call that calls the terminal device, and the call analysis device The failure cause of the call based on the control signal for calling the terminal device among the input control signals, the control signal for the call response from the terminal device, and the time-out time of each input call A call failure cause determination step for determining the call failure.

(8) One aspect of the present invention is a computer program for performing processing for analyzing a call for calling a terminal device from a base station device in a wireless communication system, and for controlling the base station device A call time for measuring a call time in the case of an incoming call failure based on an input function for inputting a control signal to be exchanged, a control signal for notifying an incoming call and a control signal for notifying an incoming call failure among the input control signals The terminal based on a measurement function, a control signal for calling the terminal device among the input control signals, a control signal for a call response from the terminal device, and a call time measured by the call time measurement function A call number estimation function for estimating an upper limit value of the number of calls for calling a device, and a control for calling the terminal device among the input control signals And the call response control signal from the terminal device, the call time measured by the call time measurement function, and the upper limit value of the number of calls estimated by the call number estimation function, A time-out time estimation function for estimating a time-out time, which is an upper limit value of a waiting time until calling, for each call to call the terminal device, a control signal for calling the terminal device among the input control signals, and the terminal device A call failure cause determination function for determining a cause of failure of the call based on a control signal of a call response from the call time and a timeout time of each call round estimated by the timeout time estimation function. It is a computer program.
(9) One aspect of the present invention is a computer program for performing processing for analyzing a call for calling a terminal device from a base station device in a wireless communication system, and for controlling the base station device An input function for inputting a control signal to be exchanged and a timeout time that is an upper limit of a waiting time until the terminal device is called and calling the terminal device, and the input function A call failure cause for determining a cause of failure of the call based on a control signal for calling the terminal device among control signals, a control signal for a call response from the terminal device, and a time-out time of each input call A computer program for causing a computer to implement a determination function.

  Advantageous Effects of Invention According to the present invention, it is possible to contribute to determining the cause of failure of a call for calling a terminal device from a base station device in a wireless communication system.

It is a block diagram which shows the structure of the call analysis apparatus 1 which concerns on one Embodiment of this invention. 1 is a schematic configuration diagram of a wireless communication network according to an embodiment of the present invention. It is a sequence chart which shows the procedure of the calling of UE_33 which concerns on one Embodiment of this invention. It is a figure which shows each example of an incoming call acceptance message and an incoming call failure message. It is a figure which shows each example of the response message of a call message and a call response. It is a conceptual diagram for demonstrating the call frequency estimation method which concerns on one Embodiment of this invention. It is a flowchart which shows an example of the call frequency estimation process which concerns on one Embodiment of this invention. It is a conceptual diagram for demonstrating the timeout time estimation method which concerns on one Embodiment of this invention. It is a flowchart which shows an example of the timeout time estimation process which concerns on one Embodiment of this invention. It is an example of a state transition diagram in the call failure cause determination processing according to an embodiment of the present invention. It is a flowchart which shows an example of the call failure cause determination process which concerns on one Embodiment of this invention. It is a flowchart which shows an example of the call failure cause determination process which concerns on one Embodiment of this invention. It is a figure which shows the example of the extraction result of the call event which concerns on one Embodiment of this invention. It is a figure showing an example of a series of input events concerning one embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a wireless communication network using an EPC network function will be described as an example. As a wireless communication network using the network function of EPC, for example, a wireless communication system (LTE system) called LTE (Long Term Evolution) is known. A voice call service realized by the LTE system is called VoLTE (Voice over LTE).

  FIG. 1 is a block diagram showing a configuration of a call analysis device 1 according to an embodiment of the present invention. In FIG. 1, the call analysis device 1 includes an input unit 11, an output unit 12, a call time measurement unit 13, a call count estimation unit 14, a timeout time estimation unit 15, and a call failure cause determination unit 16. These units are configured to exchange data.

  FIG. 2 is a schematic configuration diagram of a wireless communication network according to the present embodiment. In FIG. 2, MME_30 is connected to S-GW_31 and eNB_32. eNB_32 performs radio communication with UE_33. eNB_32 is a base station apparatus. MME_30 is a base station controller. UE_33 is a terminal device. The call analysis device 1 receives a control signal exchanged via the S1-MME interface and a control signal exchanged via the S11 interface. The S1-MME interface is an interface between eNB_32 and MME_30. The S11 interface is an interface between MME_30 and S-GW_31.

FIG. 3 is a sequence chart showing a procedure for calling UE_33 according to the present embodiment.
(Step S1) When there is an incoming call to UE_33, S-GW_31 transmits an incoming call acceptance message (Downlink Data Notification Acknowledgement), which is a control signal for notifying the incoming call, to MME_30.

(Step S2) When the MME_30 receives an incoming call acceptance message for notifying the incoming call to the UE_33 from the S-GW_31, the MME_30 transmits a paging message (Paging) that is a control signal for calling the UE_33 to the eNB_32.

(Step S3) When the eNB_32 receives a call message for calling the UE_33 from the MME_30, the eNB_32 wirelessly transmits a control signal for calling the UE_33.

(Steps S4 and S5) When the eNB_32 wirelessly receives a response signal to the control signal for calling the UE_33 transmitted by radio, the eNB_32 transmits a response message (Initial UE Message) that is a control signal for the call response from the UE_33 to the MME_30.

(Step S6) When the MME_30 receives the response message of the call response from the UE_33 from the eNB_32, the MME_30 transmits a control signal notifying the success of the incoming call to the S-GW_31 as a response to the incoming call acceptance message. On the other hand, when MME_30 does not receive the call response response message from UE_33 from eNB_32 and determines that the call has failed, MME_30 receives an incoming call failure message (Downlink Data Notification) as a control signal for notifying the incoming call failure as a response to the incoming call acceptance message. Failure Indication) is sent to the S-GW.

  FIG. 4 is a diagram illustrating examples of an incoming call acceptance message and an incoming call failure message. The incoming call acceptance message is transmitted from S-GW_31 to MME_30 through the S11 interface. The incoming call failure message is transmitted from the MME_30 to the S-GW_31 via the S11 interface. “Message Type” indicates the type of message, “177” indicates an incoming call acceptance message, and “70” indicates an incoming call failure message. “TE ID” is a message identifier (ID). “Time” indicates time and is expressed in epoch seconds.

  FIG. 5 is a diagram illustrating examples of a call message and a response message of a call response. The paging message is transmitted from the MME_30 to the eNB_32 through the S1-MME interface. The response message of the call response is transmitted from the eNB_32 to the MME_30 through the S1-MME interface. “Message Type” indicates a message type, “10” indicates a call message, and “12” indicates a response message of the call response. “Time” indicates time and is expressed in epoch seconds. “UE ID” is the ID of UE_33, and “eNB ID” is the ID of eNB_32.

  Next, the operation of the call analysis device 1 according to this embodiment will be described.

[Input section]
The paging time measurement unit 13 analyzes a call that calls the UE_33 from the eNB_32 in the wireless communication system illustrated in FIG. The input unit 11 inputs a control signal exchanged by the MME_30 that controls the eNB_32. The input unit 11 inputs a control signal exchanged through the S11 interface and a control signal exchanged through the S1-MME interface. The input unit 11 inputs the control signals in order from the earliest in time sequence.

[Calling time measurement unit]
The call time measurement unit 13 measures the call time in the case of an incoming call failure based on the incoming call acceptance message and the incoming call failure message among the control signals input by the input unit 11. This measuring method will be described below.

  The call time measurement unit 13 combines an incoming call acceptance message and an incoming call failure message having the same “TE ID”. The ringing time measurement unit 13 calculates the elapsed time from the “Time” of the incoming call acceptance message to the “Time” of the incoming call failure message from each “Time” of the incoming call acceptance message and the incoming failure message of the same set. The call time measurement unit 13 obtains a call time in the case of an incoming call failure based on the calculated elapsed time of each set of an incoming call acceptance message and an incoming call failure message. For example, the call time measurement unit 13 obtains a frequency distribution for the calculated elapsed time of each set of the incoming call acceptance message and the incoming call failure message, and the elapsed time which is the mode value in the frequency distribution is a case where the incoming call fails. Call time.

[Number of calls estimation unit]
The number-of-calls estimation unit 14 determines the number of calls to call the UE_33 based on the call message and the response message of the call response among the control signals input from the input unit 11 and the call time measured by the call time measurement unit 13. Estimate the upper limit. FIG. 6 is a conceptual diagram for explaining the call frequency estimation method according to the present embodiment. When the MME_30 does not receive the response message of the call response from the call target UE_33 from the eNB_32, the MME_30 repeatedly transmits the call message for calling the call target UE_33 to the eNB_32 until the upper limit value N of the number of calls for calling the UE_33. In the present embodiment, the response message of the call response from the call target UE_33 is provided on the condition that the elapsed time from the first call message for calling the call target UE_33 exceeds the call time measured by the call time measuring unit 13. The upper limit value N of the number of calls for calling UE_33 is estimated based on the number of transmissions of no call message. For example, the frequency distribution of the number of transmissions is obtained, and the number of transmissions that is the mode value in the frequency distribution is set as the upper limit value N of the number of calls.

FIG. 7 is a flowchart illustrating an example of a call count estimation process according to the present embodiment.
(Step S101) The call count estimation unit 14 reads an event. This event is a control signal input by the input unit 11.

(Step S102) The number-of-calls estimation unit 14 inputs “Time” at which the event is received into the variable NT. This “Time” is “Time” of the control signal of the event read in step S101.

(Step S103) The call count estimation unit 14 determines whether the “Message Type” of the event read in Step S101 is “12”. If “Message Type” is “12”, the process proceeds to step S104. If not, the process proceeds to step S108.

(Step S104) Since the event is “Message Type = 12”, it is a “call response message”. The number-of-calls estimation unit 14 determines whether there is an event associated with the “UE ID” of the event “call response message”. As a result, if there is a corresponding event, the process proceeds to step S105. If not, the process proceeds to step S106.

(Step S105) The call count estimation unit 14 initializes the value of the event counter c associated with “UE ID” of the event “call response message” to 0. Thereafter, the process proceeds to step S107.

(Step S106) The number-of-calls estimation unit 14 creates an event associated with the “UE ID” of the event “response message for call response”. The created event includes a counter c of the event. Thereafter, the process proceeds to step S105.

(Step S107) The call count estimation unit 14 determines whether all the events have been read. This event is intended for all control signals input by the input unit 11. If all the events are read as a result of this determination, the process proceeds to step S111. If not, the process returns to step S101.

(Step S108) The number-of-calls estimation unit 14 determines whether the “Message Type” of the event read in Step S101 is “10”. If “Message Type” is “10”, the process proceeds to step S109. If not, the process proceeds to step S107.

(Step S109) Since the event is “Message Type = 10”, it is a “call message”. The number-of-calls estimation unit 14 determines whether there is an event associated with the “UE ID” of the event “call message”. As a result, if there is a corresponding event, the process proceeds to step S110. If not, the process proceeds to step S107.

(Step S110) The call count estimation unit 14 adds 1 to the value of the event counter c associated with the “UE ID” of the event “call message”. Then, the call count estimation unit 14 inputs the value of the variable NT as the value of the event occurrence time T associated with the “UE ID” of the event “call message”.

(Step S111) The number-of-calls estimation unit 14 estimates an upper limit value N of the number of calls. In this estimation, first, the call count estimation unit 14 calculates a time NT_a obtained by subtracting the call time measured by the call time measurement unit 13 from the value of the variable NT. Next, the number-of-calls estimation unit 14 extracts all the values of the counter c of events whose occurrence time T is smaller than the time NT_a among events associated with “UE ID”. That the value of the occurrence time T is smaller than the time NT_a is that the occurrence time T is earlier in time than the time NT_a. Therefore, all the extraction target events are events in which the elapsed time from the first time of the call message for calling the call target UE_33 exceeds the call time measured by the call time measurement unit 13. Next, the call count estimation unit 14 estimates the upper limit value N of the call count based on the extracted value of the counter c. For example, a frequency distribution of the values of the extracted counter c is obtained, and the value of the counter c which is the most frequent value in the frequency distribution is set as the upper limit value N of the number of calls.

  In the call number estimation process of FIG. 7 described above, an incoming failure event is extracted by paying attention to the fact that the call message after the call response response message is the first call message in the same “UE ID”. If the call message is transmitted and fails, the call message transmission is repeated up to the upper limit value N of the number of calls. If the call message is transmitted successfully, a call response message is received. From this, for each “UE ID”, that is, for each UE_33, the upper limit value N of the number of calls is estimated from, for example, a statistical value of the number of transmissions based on the number of transmissions of the call message that does not receive the response message of the call response.

[Timeout time estimation section]
The time-out time estimation unit 15 is estimated by the call number estimation unit 14 and the call message measured by the call time measurement unit 13 among the control messages input from the input unit 11 and the response message of the call response. Based on the upper limit value N of the number of calls, a time-out period that is an upper limit value of the waiting time until the UE_33 is called is estimated for each call of calling the UE_33.

  FIG. 8 is a conceptual diagram for explaining a timeout time estimation method according to the present embodiment. In the example of FIG. 8, the upper limit value N of the number of calls is 3 times. When the MME_30 does not receive the response message of the call response from the call target UE_33 from the eNB_32 even after the timeout time T_1 has elapsed since the first call message for calling the call target UE_33 is transmitted to the eNB_32, the MME_30 again A second call message for calling the call target UE_33 is transmitted to the eNB_32. Then, when the MME_30 does not receive a response message of the call response from the call target UE_33 from the eNB_32 even after the timeout time T_2 has elapsed since the second call message is transmitted to the eNB_32, A third call message for calling UE_33 is transmitted to eNB_32. Then, when the MME_30 does not receive the call response response message from the call target UE_33 from the eNB_32 even after the timeout time T_3 has elapsed since the transmission of the third call message to the eNB_32, the MME_30 returns to the S-GW_31. An incoming call failure message for the corresponding incoming call acceptance message is transmitted.

  In the present embodiment, the time-out time is estimated for each call by obtaining the time interval of the call message for each call. However, the call time measuring unit 13 measures the timeout time (timeout time T_3 in the example of FIG. 8) after transmitting the call message of the upper limit value of the number of calls (third call message in the example of FIG. 8). The sum of all time-out times (time-out times T_1 and T_2 in the example of FIG. 8) related to the call messages before the upper limit value of the number of calls (the first and second call messages in the example of FIG. 8) Calculate as the remaining time minus time.

FIG. 9 is a flowchart illustrating an example of the timeout time estimation process according to the present embodiment.
(Step S201) The timeout time estimation unit 15 reads an event. This event is a control signal input by the input unit 11.

(Step S202) The timeout time estimation unit 15 inputs “Time” at which the event is received in the variable NT. This “Time” is “Time” of the control signal of the event read in step S201.

(Step S203) The timeout time estimation unit 15 determines whether the “Message Type” of the event read in Step S201 is “12”. If “Message Type” is “12”, the process proceeds to step S204. If not, the process proceeds to step S208.

(Step S204) Since the event is “Message Type = 12”, it is a “call response message”. The timeout time estimation unit 15 determines whether there is an event associated with the “UE ID” of the event “call response message”. As a result, if there is a corresponding event, the process proceeds to step S205. If not, the process proceeds to step S206.

(Step S205) The timeout time estimation unit 15 initializes the value of the number of retransmissions n of the event associated with the “UE ID” of the event “call response message” to 0, and sets the timer Tn of the number of retransmissions n to the number of retransmissions. It is initialized to the timer T0 of “n = 0”. Thereafter, the process proceeds to step S207.

(Step S206) The timeout time estimation unit 15 creates an event associated with the “UE ID” of the event “response message of call response”. The created event includes a retransmission count n of the event and a timer Tn for the retransmission count n. Thereafter, the process proceeds to step S205.

(Step S207) The timeout time estimation unit 15 determines whether all the events have been read. This event is intended for all control signals input by the input unit 11. If all the events are read as a result of this determination, the process proceeds to step S213. If not, the process returns to step S201.

(Step S208) The timeout time estimation unit 15 determines whether the “Message Type” of the event read in Step S201 is “10”. If “Message Type” is “10”, the process proceeds to step S209. If not, the process proceeds to step S207.

(Step S209) Since the event is “Message Type = 10”, it is a “call message”. The timeout time estimation unit 15 determines whether there is an event associated with the “UE ID” of the event “call message”. As a result, if there is a corresponding event, the process proceeds to step S210. If not, the process proceeds to step S207.

(Step S210) The timeout time estimation unit 15 determines whether the value of n of the timer Tn is zero. If the result of this determination is 0, the process proceeds to step S211. If not, the process proceeds to step S212.

(Step S211) The timeout time estimation unit 15 inputs the value of the variable NT into the variable t associated with the “UE ID” of the event “call message”. Then, the timeout time estimation unit 15 adds 1 to the value of n of the timer Tn. Thereafter, the process proceeds to step S207.

(Step S212) The timeout time estimation unit 15 sets a difference obtained by subtracting the value of the variable t associated with the “UE ID” of the event “call message” from the value of the variable NT as the value of the timer Tn. Then, the timeout time estimation unit 15 inputs the value of the variable NT to the variable t associated with the “UE ID” of the event “call message”. Then, the timeout time estimation unit 15 adds 1 to the value of n of the timer Tn. Thereafter, the process proceeds to step S207.

(Step S213) The timeout time estimation unit 15 estimates the timeout time of each call. In this estimation, first, the timeout time estimation unit 15 calculates a time NT_a obtained by subtracting the call time measured by the call time measurement unit 13 from the value of the variable NT. Next, the timeout time estimation unit 15 extracts all the values of the timer Tn of the events having a value of the variable t smaller than the time NT_a among the events associated with “UE ID”. Next, the timeout time estimation unit 15 estimates the timeout time of the nth call based on the value of the timer Tn for each timer Tn. However, n is from 1 to N-1. N is an upper limit value of the number of calls estimated by the number-of-calls estimation unit 14. For example, a frequency distribution of the extracted timer Tn values is obtained, and the value of the timer Tn which is the most frequent value in the frequency distribution is set as the timeout time of the nth call. Next, the timeout time estimation unit 15 estimates the timeout time of the Nth call that is the upper limit value of the number of calls. In this estimation, the remaining time obtained by subtracting the total time of the timeout time from the first call time to the “N−1” th call time from the call time measured by the call time measurement unit 13 is used as the Nth call. Times out.

  In the timeout time estimation process of FIG. 9 described above, an incoming failure event is extracted by paying attention to the fact that the call message after the call response message is the first call message in the same “UE ID”. If the call message is transmitted and fails, the call message transmission is repeated up to the upper limit value N of the number of calls. If the call message is transmitted successfully, a call response message is received. Therefore, for each “UE ID”, that is, for each UE_33, based on the transmission interval from the call message that does not receive the response message of the call response to the next call message, for example, from the statistics of the transmission interval, Estimate the timeout time.

  According to the above-described embodiment, it is possible to estimate the timeout time of each call that calls UE_33.

[Call failure cause determination section]
The call failure cause determination unit 16 determines the UE_33 based on the call message and the response message of the call response among the control signals input by the input unit 11, and the time-out time of each call estimated by the time-out time estimation unit 15. Determine the cause of the call failure. In the present embodiment, the cause of the call failure is determined from three failure causes: (1) UE_33 movement, (2) eNB_32 factor, and (3) UE_33 out of service area.

(1) Call failure due to movement of UE_33 can be identified as a successful call event outside the call area of the previous failed call among the successful call events. This is because, for example, the UE_33 has been called by using the call area where the UE_33 was in the most recent past as the first call area, but the call failed to the call area around the first call area. This is a case where UE_33 is successfully called. In this case, the UE_33 moving from the first call area to the call area around the first call area is considered to be the cause of the failure of the call to the first call area.

(2) The failure of the call due to the eNB_32 factor can be identified as a successful call event in the same call area as the previous unsuccessful call among the successful call events. This is the case, for example, when a UE_33 call is made to the first call area but fails, and then the UE_33 call to the same first call area is successful. In this case, although UE_33 was located in the first call area, it is considered that the call to the first call area has failed due to factors such as congestion of eNB_32 in the first call area.

(3) Call failure due to out of service area of the UE_33 can be identified as an event in which there is no response to the call even after waiting for the total time of the timeout time of each call. It is considered that this is because the call target UE_33 is not located within the call area of each eNB_32 handled by the MME_30.

  FIG. 10 is an example of a state transition diagram in the call failure cause determination processing according to the present embodiment. In the example of FIG. 10, the upper limit value N of the number of calls is 3 times. In FIG. 10, “Stage1” is a state in which the MME_30 transmits the first call message for calling the call target UE_33. “Stage2” is a state in which the MME_30 transmits a second call message for calling the call target UE_33. “Stage3” is a state in which the MME_30 transmits a third call message for calling the call target UE_33. “Failed” is a state where the call has failed.

  11 and 12 are flowcharts showing an example of a call failure cause determination process according to the present embodiment. In the examples of FIGS. 11 and 12, the upper limit value N of the number of calls is 3 times, and the state transition diagram illustrated in FIG. 10 is used.

  First, the call failure cause determination process of FIG. 11 will be described. When receiving the event type 10, the call failure cause determination unit 16 starts the call failure cause determination process of FIG. The reception of the event type 10 means that a call message (Message Type = 10) is input by the input unit 11. This input call message is hereinafter referred to as an input call message.

(Step S301) The call failure cause determination unit 16 inputs the reception time of the event type 10 to the variable T. The reception time of event type 10 is “Time” of the input call message.

(Step S302) The call failure cause determination unit 16 determines whether there is a call event associated with the “UE ID” of the input call message. As a result, if there is a corresponding call event, the process proceeds to step S307. If not, the process proceeds to step S303.

(Step S303) The call failure cause determination unit 16 creates a call event associated with the “UE ID” of the input call message.

(Step S304) The call failure cause determination unit 16 inputs the value of the variable T at the call event creation time T0 of the call event associated with the “UE ID” of the input call message.

(Step S305) The call failure cause determination unit 16 sets the state c of the call event associated with “UE ID” of the input call message to “Stage1”.

(Step S306) The call failure cause determination unit 16 records “eNB ID” of the input call message. At this time, the call reception count Bn of the “eNB ID” is initialized to 1. Thereafter, the process of FIG. 11 is terminated.

(Step S307) This is a case where there is a call event associated with “UE ID” of the input call message. The call failure cause determination unit 16 subtracts the value of the call event creation time T0 of the call event associated with the “UE ID” of the input call message from the value of the variable T. The call failure cause determination unit 16 determines whether the difference between the subtraction results is smaller than the timeout time total value timer_all. If it is determined that the result is smaller, the process proceeds to step S314. If not, the process proceeds to step S308. The total time-out value timer_all is the total time-out time of each call estimated by the time-out time estimation unit 15. In this example, the total time is the sum of the first time-out time timer1, the second time-out time timer2, and the third time-out time timer3.

(Step S308) This is a case where the difference obtained by subtracting the value of the call event creation time T0 from the value of the variable T is equal to or greater than the total timeout time timer_all. The call failure cause determination unit 16 sets the state c of the call event associated with “UE ID” of the input call message to “Failed”. The call failure cause determination unit 16 determines the call event as a call failure.

(Step S309) The call failure cause determination unit 16 records the determined call event as an extraction event. Then, the call failure cause determination unit 16 deletes the call event associated with the “UE ID” of the input call message.

(Step S310) The call failure cause determination unit 16 newly creates a call event associated with the “UE ID” of the input call message.

(Step S311) The call failure cause determination unit 16 inputs the value of the variable T at the call event creation time T0 of the call event associated with the “UE ID” of the input call message.

(Step S312) The call failure cause determination unit 16 sets the state c of the call event associated with “UE ID” of the input call message to “Stage1”.

(Step S313) The call failure cause determination unit 16 records “eNB ID” of the input call message. At this time, the call reception count Bn of the “eNB ID” is initialized to 1. Thereafter, the process of FIG. 11 is terminated.

(Step S314) This is a case where the difference obtained by subtracting the value of the call event creation time T0 from the value of the variable T is less than the total timeout time value timer_all. The call failure cause determination unit 16 adds 1 to the call reception count Bn for each “eNB ID” of the call event associated with the “UE ID” of the input call message.

(Step S315) The call failure cause determination unit 16 determines whether the state c of the call event associated with the “UE ID” of the input call message is “Stage1” and the call reception count Bn is two. If the result of this determination is true, the process proceeds to step S316. Otherwise, the process proceeds to step S317.

(Step S316) The call failure cause determination unit 16 sets the state c of the call event associated with “UE ID” of the input call message to “Stage2”.

(Step S317) The call failure cause determination unit 16 determines whether the state c of the call event associated with the “UE ID” of the input call message is “Stage2” and the number of call receptions Bn is three. If the result of this determination is true, the process proceeds to step S318. Otherwise, the process of FIG. 11 is terminated.

(Step S318) The call failure cause determination unit 16 sets the state c of the call event associated with “UE ID” of the input call message to “Stage3”.

  Next, the call failure cause determination process of FIG. 12 will be described. When the call failure cause determination unit 16 receives the event type 12, the call failure cause determination unit 16 starts the call failure cause determination process of FIG. The reception of the event type 12 means that a response message (Message Type = 12) of a call response is input by the input unit 11. This input response message of the call response is hereinafter referred to as an input response message.

(Step S401) The call failure cause determination unit 16 inputs the reception time of the event type 12 to the variable T. The reception time of the event type 12 is “Time” of the input response message.

(Step S402) The call failure cause determination unit 16 determines whether there is a call event associated with the “UE ID” of the input response message. As a result, if there is a corresponding call event, the process proceeds to step S403. Otherwise, the process in FIG. 12 is terminated.

(Step S403) The call failure cause determination unit 16 subtracts the value of the call event creation time T0 of the call event associated with the “UE ID” of the input response message from the value of the variable T. The call failure cause determination unit 16 determines whether the difference between the subtraction results is smaller than the timeout time total value timer_all. If the result of this determination is that it is smaller, the process proceeds to step S404. If not, the process proceeds to step S406. The total time-out value timer_all is the total time-out time of each call estimated by the time-out time estimation unit 15. In this example, the total time is the sum of the first time-out time timer1, the second time-out time timer2, and the third time-out time timer3.

(Step S404) The call failure cause determination unit 16 determines the current state c of the call event associated with the “UE ID” of the input response message.

(Step S405) The call failure cause determination unit 16 records the determined call event as an extraction event. Then, the call failure cause determination unit 16 deletes the call event associated with the “UE ID” of the input response message. Thereafter, the process of FIG. 12 is terminated.

(Step S406) This is a case where the difference obtained by subtracting the value of the call event creation time T0 from the value of the variable T is equal to or greater than the total timeout time timer_all. The call failure cause determination unit 16 sets the state c of the call event associated with “UE ID” of the input response message to “Failed”. The call failure cause determination unit 16 determines the call event as a call failure.

(Step S407) The call failure cause determination unit 16 records the determined call event as an extraction event. Then, the call failure cause determination unit 16 deletes the call event associated with the “UE ID” of the input response message. Thereafter, the process of FIG. 12 is terminated.

  FIG. 13 is a diagram showing an example of a call event extraction result according to the present embodiment. This extraction result is recorded as an extraction event by the above-described call failure cause determination processing of FIG. 11 and FIG. In FIG. 13, the response time is a value of “T−T0”. The state is the determined state c of the call event. “ENB ID” is the recorded “eNB ID”. In “Success outside the previous call area”, “True” indicates that the call was successful outside the previous call area, and “False” indicates that the call was successful in the same call area as the previous time. “True” of “success outside the previous call area” is an extraction event by event type 12, that is, an input response message, and “eNB ID” in which the extraction event is recorded and “UE ID” same as the extraction event. "ENB ID" recorded in the previous call event associated with "" is different. On the other hand, “False” of “success outside the previous call area” is an extraction event based on the event type 12, that is, an input response message, and the same “eNB ID” in which the extraction event is recorded as “ This is a case where the “eNB ID” recorded in the previous call event associated with “UE ID” is the same.

In the call event extraction result according to the present embodiment, the failure of the call due to movement of UE_33 is when the status is “Stage2” or “Stage3” and “Success outside the previous call area” is “True”. . Call failure due to eNB_32 factor is
This is a case where the state is “Stage2” or “Stage3” and “Success outside the previous call area” is “False”. The failure of the call due to the UE_33 being out of service is when the state is “Failed”. The output unit 12 outputs information indicating the cause of call failure.

  FIG. 14 is a diagram illustrating an example of a series of input events according to the present embodiment. In the example of the series of input events in FIG. 14, the upper limit value N of the number of calls is 3 times, and the timeout time of each call time is the same 3 seconds. In the series of input events of FIG. 14, there are two call events. One call event is a message group with “UE ID” of “aa: aa: aa: aa”, and the other call event is a message group with “UE ID” of “bb: bb: bb: bb” .

  For the message group with “UE ID” “aa: aa: aa: aa”, the first call message is sent at time “1398830753”, and the response message for the call response to the first call message is the timeout period (3 seconds ), The second call message is transmitted at time “1398830756”. Thereafter, at time “1398830757”, a response message for the call response to the second call message was received, and the terminal call was successful with the second call message. Therefore, the call failure cause determination unit 16 determines that this call event has succeeded by the second call message. Further, a response message for the call response is transmitted outside the first call area (“eNB ID” is “100000”) (“eNB ID” is “100001”). For this reason, the call failure cause determination unit 16 determines that the cause of the first failure of this call event is the movement of the UE_33. If a call response response message is transmitted from the same call area as the first call area (“eNB ID” is “100,000”), the call failure cause determination unit 16 determines the first call event of the call event. It determines with the cause of failure being a factor of eNB_32.

  For the message group with “UE ID” “bb: bb: bb: bb”, the first call message is sent at time “1398830754”, and the response message for the call response to the first call message is the timeout time (3 seconds) ), The second call message is transmitted at time “1398830757”. Thereafter, since the response message for the call response to the second call message is not received within the timeout time (3 seconds), the third call message is transmitted at time “1398830760”. Thereafter, since the response message for the call response to the third call message is not received within the timeout time (3 seconds), the call failure cause determination unit 16 determines that this call event has failed. In this case, since there is no response from the UE_33 even if the call message is transmitted three times, the call failure cause determination unit 16 fails the call event because the state of the UE_33 is out of service area where the call signal cannot be wirelessly received. Is determined.

  According to the above-described embodiment, there is an effect that it is possible to contribute to the determination of the cause of failure of the call for calling UE_33 from eNB_32 in the wireless communication system.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

  For example, the input unit 11 may input a timeout time for each call. The call failure cause determination unit 16 may use the timeout time of each call entered by the input unit 11. In this case, the call time measurement unit 13, the call count estimation unit 14, and the timeout time estimation unit 15 may not be provided.

  The input unit 11 may input a control signal exchanged via the S11 interface and a control signal exchanged via the S1-MME interface in real time online, or may be input offline in non-real time. Also good.

  In the above-described embodiment, the wireless communication network using the EPC network function has been described as an example, but the present invention can be similarly applied to other wireless communication networks.

Further, a computer program for realizing the function of the above-described call analysis device 1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into the computer system and executed. Good. Here, the “computer system” may include an OS and hardware such as peripheral devices.
“Computer-readable recording medium” refers to a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disk), and a built-in computer system. A storage device such as a hard disk.

Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1 ... Call analysis apparatus, 11 ... Input part, 12 ... Output part, 13 ... Call time measurement part, 14 ... Calling number estimation part, 15 ... Timeout time estimation part, 16 ... Call failure cause determination part, 30 ... MME (base) Station control device), 31 ... S-GW, 32 ... eNB (base station device), 33 ... UE (terminal device)

Claims (9)

A call analysis device that analyzes a call for calling a terminal device from a base station device in a wireless communication system,
An input unit for inputting a control signal exchanged by the base station controller that controls the base station device;
A call time measuring unit for measuring a call time in the case of an incoming call failure based on a control signal for notifying an incoming call and a control signal for notifying an incoming call failure among the input control signals;
A call for calling the terminal device based on a control signal for calling the terminal device among the input control signals, a control signal for a call response from the terminal device, and a call time measured by the call time measuring unit. A number-of-calls estimation unit that estimates an upper limit of the number of times
Of the input control signals, the control signal for calling the terminal device, the control signal for the call response from the terminal device, the call time measured by the call time measurement unit, and the call number estimation unit estimated Based on the upper limit value of the number of calls, a timeout time estimation unit that estimates a timeout time that is an upper limit value of the waiting time until the terminal device is called, for each call that calls the terminal device;
Based on the control signal for calling the terminal device among the input control signals, the control signal for the call response from the terminal device, and the timeout time of each call estimated by the timeout time estimation unit, the call A call failure cause determination unit that determines the cause of failure,
Call analysis device with A call analysis device that analyzes a call for calling a terminal device from a base station device in a wireless communication system,
A control signal exchanged by the base station controller that controls the base station device, a timeout time that is an upper limit value of a waiting time until the terminal device is called, and a timeout time of each call that calls the terminal device; An input unit for inputting
Based on the control signal for calling the terminal device among the input control signals, the control signal for the call response from the terminal device, and the time-out time of each input call, the cause of the call failure is determined. A call failure cause determination unit to perform,
Call analysis device with The call failure cause determination unit determines that the cause of the failure is the movement of the terminal device for a call event that is successful outside the call area of the previous failed call among the events in which the call is successful.
The call analysis device according to claim 1 or 2. The call failure cause determination unit determines that the cause of the failure is a factor of the base station apparatus for a call event that succeeded in the same call area as the previous failed call among the events that the call was successful. ,
The call analysis device according to any one of claims 1 to 3. The call failure cause determination unit determines that the cause of the failure is out of the service area of the terminal device for a failure event in which there is no response to the call even after waiting for the total timeout time of each call.
The call analysis device according to any one of claims 1 to 4. A call analysis method for analyzing a call for calling a terminal device from a base station device in a wireless communication system,
An input step in which a call analysis device inputs a control signal exchanged by a base station controller that controls the base station device;
A call time measuring step in which the call analysis device measures a call time in the case of an incoming call failure based on a control signal for notifying an incoming call and a control signal for notifying an incoming call failure among the input control signals;
Based on the control signal for calling the terminal device and the control signal for the call response from the terminal device among the input control signals, and the call time measured by the call time measurement step, the call analysis device, A call frequency estimation step for estimating an upper limit value of the call frequency for calling the terminal device;
The call analysis device includes a control signal for calling the terminal device, a control signal for a call response from the terminal device, a call time measured by the call time measurement step, and the number of calls. A time-out time estimating step for estimating a time-out time, which is an upper-limit value of a waiting time until the terminal device is called, based on an upper limit value of the number of calls estimated in the estimating step, for each time of calling the terminal device; ,
The call analysis device includes a control signal for calling the terminal device among the input control signals, a control signal for a call response from the terminal device, and a timeout time of each call estimated by the timeout time estimation step. Call failure cause determination step for determining a failure cause of the call based on
Call analysis method including: A call analysis method for analyzing a call for calling a terminal device from a base station device in a wireless communication system,
Each call cycle in which the call analysis device calls the terminal device with a control signal exchanged by the base station control device that controls the base station device and a timeout time that is an upper limit of a waiting time until the terminal device is called A time-out period, and an input step for inputting,
Based on the control signal for calling the terminal device and the control signal for the call response from the terminal device among the input control signals, and the time-out time of each input call, the call analysis device A call failure cause determination step for determining a call failure cause; and
Call analysis method including: A computer program for performing processing for analyzing a call for calling a terminal device from a base station device in a wireless communication system,
An input function for inputting a control signal exchanged by a base station controller that controls the base station device;
A call time measurement function for measuring a call time in the case of an incoming call failure based on a control signal for notifying an incoming call and a control signal for notifying an incoming call failure among the input control signals;
A call for calling the terminal device based on a control signal for calling the terminal device, a control signal for a call response from the terminal device, and a call time measured by the call time measurement function. A call frequency estimation function for estimating the upper limit of the frequency,
Of the input control signals, the control signal for calling the terminal device, the control signal for the call response from the terminal device, the call time measured by the call time measurement function, and the call frequency estimation function Based on the upper limit value of the number of calls, a timeout time estimation function that estimates a timeout time that is an upper limit value of the waiting time until the terminal device is called for each call that calls the terminal device;
Based on the control signal for calling the terminal device among the input control signals, the control signal for the call response from the terminal device, and the timeout time of each call estimated by the timeout time estimation function, the call Call failure cause determination function to determine the cause of failure,
A computer program for realizing a computer. A computer program for performing processing for analyzing a call for calling a terminal device from a base station device in a wireless communication system,
A control signal exchanged by the base station controller that controls the base station device, a timeout time that is an upper limit value of a waiting time until the terminal device is called, and a timeout time of each call that calls the terminal device; Input function to input
Based on the control signal for calling the terminal device among the input control signals, the control signal for the call response from the terminal device, and the time-out time of each input call, the cause of the call failure is determined. Call failure cause determination function,
A computer program for realizing a computer.

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