JP2012124707A - Fault detection method, radio terminal, and base station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the deterioration of service quality by detecting the silent fault of a base station.SOLUTION: A fault detection method of one embodiment includes: a step for allowing a radio terminal 100 corresponding to multiple radio access systems to transmit failure notification information indicating that connection to a base station 200A is failed to a base station 200B, which is included in a radio access network 10B with a radio access system different from that of a radio access network 10A, after connection to the base station 200A included in the radio access network 10A is failed; a step for allowing the base station 200B to transmit alarm information to a monitoring device 300B when receiving the failure notification information from the radio terminal 100; and a step for allowing the monitoring device 300B to detect the silent fault of the base station 200A on the basis of the alarm information from the base station 200B.

Description

  The present invention relates to a failure detection method, a wireless terminal, and a base station for detecting a failure in a network.

  In network operation, it is important to quickly detect and quickly repair failures of each device that constitutes the network in order to maintain good service quality. Monitoring devices for detecting failures are included in the network. It is common to be provided. The monitoring device determines whether or not a failure has occurred by measuring the communication performance of each device in the network (for example, packet loss or transfer delay during data transfer).

  In recent years, “silent failure”, which is a failure in which the performance of a network is deteriorated without being detected by such a monitoring device, has been regarded as a problem. When a silent failure occurs, the quality of service experienced by a user using the network is low even when no error is reported from the monitoring device to the network operator.

  A method for automatically detecting silent failures is when the monitoring device collects performance data, which is a statistical value of network device communication performance, and the results of comparing the performance data with past performance data are inconsistent A method for estimating that a silent failure has occurred has been proposed (see, for example, Patent Document 1).

JP 2010-86160 A

  However, in the method of comparing the collected performance data with the past performance data, the pattern of the collected performance data varies, so the results compared with the past performance data often do not match, and silent failure detection There was a problem that it was difficult to improve accuracy.

  In addition, in the case where a wireless terminal cannot be connected to the base station due to a failure in a base station included in the network, the base station and the monitoring device recognize that the wireless terminal has failed to connect to the base station. Cannot be reflected in the performance data. Accordingly, there is a problem that such a silent failure of the base station is difficult to detect on the network side.

  Therefore, an object of the present invention is to provide a failure detection method, a wireless terminal, and a base station that can prevent a deterioration in service quality by making it possible to detect a silent failure of a base station.

  In order to solve the above-described problems, the present invention has the following features. First, the failure detection method according to the present invention is characterized in that a wireless terminal (wireless terminal 100) corresponding to a plurality of wireless access schemes (RAT: Radio Access Technology) is included in the first network (wireless access network 10A). After failing to connect to the first base station (base station 200A), the second base station (base station) included in the second network (radio access network 10B) having a radio access scheme different from that of the first network A step of transmitting failure notification information indicating failure in connection to the first base station to the station 200B), and when the second base station receives failure notification information from the wireless terminal, Transmitting alarm information to a predetermined network device (monitoring device 300A, monitoring device 300B, base station 200A, or monitoring device 350) The predetermined network device detects, based on alarm information from the second base station, a specific failure that is a failure of the first base station and is difficult to detect in the first network; The gist is to include.

  According to such a feature, the specific failure (silent failure) of the first base station included in the first network is caused by the second network included in the second network having a radio access scheme different from that of the first network. Can be detected via a base station. Therefore, according to the above feature, it is possible to avoid degradation of service quality by making it possible to detect a silent failure of a base station.

  Another feature of the failure detection method according to the present invention is that in the failure detection method according to the above feature, the predetermined network device is a monitoring device (monitoring device 300B) included in the second network. And

  Another feature of the failure detection method according to the present invention is that in the failure detection method according to the above feature, the predetermined network device is a monitoring device (monitoring device 300A) included in the first network. And

  Another feature of the failure detection method according to the present invention is that, in the failure detection method according to the feature described above, the predetermined network device is the first base station.

  Another feature of the failure detection method according to the present invention is the failure detection method according to the above feature, wherein the predetermined network device is a monitoring device included in the first network and a monitoring included in the second network. The gist is that each of the devices is a higher-level monitoring device (monitoring device 350).

  Another feature of the failure detection method according to the present invention is the failure detection method according to the above feature, wherein the wireless terminal is connected to the first base station based on broadcast information received from the first base station. As a result, the failure notification information is transmitted to the second base station after the connection to the first base station fails.

  Another feature of the failure detection method according to the present invention is the failure detection method according to the above feature, wherein the wireless terminal uses the identification information of the first network and / or the identification information of the first base station as the failure. The second base station transmits the alarm information including the identification information included in the failure notification information from the wireless terminal.

  Another feature of the failure detection method according to the present invention is the failure detection method according to the above feature, wherein the wireless terminal includes information indicating a type of connection failure to the first base station in the failure notification information. And the type of connection failure includes random access failure or wireless link disconnection.

  Another feature of the failure detection method according to the present invention is the failure detection method according to the above feature, wherein the predetermined network device obtains a plurality of alarm information corresponding to a plurality of wireless terminals within a predetermined time range. In this case, it is determined that the specific failure has occurred in the first base station.

  Another feature of the failure detection method according to the present invention is the failure detection method according to the above feature, wherein the communication area range of the first base station and the communication area range of the second base station overlap at least partially. The gist is to do.

  Another feature of the failure detection method according to the present invention is that in the failure detection method according to the above feature, after the specific failure is detected, the first base station is connected to the first base station. The gist is to stop the transmission of the broadcast information used.

  Another feature of the failure detection method according to the present invention is that, in the failure detection method according to the above feature, after the specific failure is detected, the first base station establishes a connection to the first base station. The gist is that the connection restriction information for restriction is included in the broadcast information used for connection to the first base station and transmitted.

  Another feature of the failure detection method according to the present invention is that, in the failure detection method according to the above feature, after the specific failure is detected, the second base station expands a communication area range of the own station. The gist is to do.

  The wireless terminal according to the present invention is characterized by a plurality of wireless communication units (wireless communication units 110A and 110B) provided for each of a plurality of wireless access methods, and a control unit (control unit 140) that controls the plurality of wireless communication units. ), And the controller is wireless with the first network after failing to connect to the first base station (base station 200A) included in the first network (radio access network 10A). Failure notification information indicating failure in connection to the first base station is transmitted to a second base station (base station 200B) included in a second network (radio access network 10B) having a different access method. Thus, the gist is to control the plurality of wireless communication units.

  A feature of the base station according to the present invention is a base station (base station 200B) included in a second network (radio access network 10B) having a radio access scheme different from that of the first network (radio access network 10A). A wireless communication unit (wireless communication unit 210) that performs wireless communication, a network communication unit (network communication unit 220) that performs network communication, and a control unit (control unit 240) that controls the wireless communication unit and the network communication unit And the control unit fails to connect to a first base station (base station 200A) included in the first network from a wireless terminal (wireless terminal 100) that supports a plurality of wireless access methods. When the wireless communication unit receives the failure notification information indicating that it has been performed, the predetermined network device (the monitoring device 300A, the monitoring device 300B, and summarized in that to control the network communication unit to transmit the base station 200A, or the alarm information to the monitoring apparatus 350).

  According to the present invention, it is possible to provide a failure detection method, a wireless terminal, and a base station that can prevent a degradation in service quality by enabling detection of a silent failure of a base station.

1 is a schematic configuration diagram of a mobile communication system according to a first embodiment. It is a block diagram which shows the structure of the radio | wireless terminal which concerns on 1st Embodiment-4th Embodiment. It is a block diagram which shows the structure of the base station which concerns on 1st Embodiment-4th Embodiment. It is a block diagram which shows the structure of the monitoring apparatus which concerns on 1st Embodiment-4th Embodiment. It is a sequence diagram which shows operation | movement of the mobile communication system which concerns on 1st Embodiment. It is a schematic block diagram of the mobile communication system which concerns on 2nd Embodiment. It is a sequence diagram which shows operation | movement of the mobile communication system which concerns on 2nd Embodiment. It is a schematic block diagram of the mobile communication system which concerns on 3rd Embodiment. It is a sequence diagram which shows operation | movement of the mobile communication system which concerns on 3rd Embodiment. It is a schematic block diagram of the mobile communication system which concerns on 4th Embodiment. It is a sequence diagram which shows operation | movement of the mobile communication system which concerns on 4th Embodiment.

  The first to fourth embodiments of the present invention and other embodiments will be described with reference to the drawings. In the drawings in the following embodiments, the same or similar parts are denoted by the same or similar reference numerals.

(0) Outline of Embodiment In the failure detection methods according to the first to fourth embodiments, a radio terminal 100 corresponding to a plurality of radio access schemes (RAT: Radio Access Technology) is connected to the radio access network 10A (first Base station 200A included in radio access network 10B (second network) having a radio access scheme different from that of radio access network 10A. A step of transmitting failure notification information indicating that the connection to the wireless communication device has failed; a step of transmitting alarm information to a predetermined network device when the base station 200B receives the failure notification information from the wireless terminal 100; Of the base station 20 based on the alarm information from the base station 200B. And detecting the detection difficult particular disorder (i.e., silent failure) in a wireless access network 10A a failure A, a.

  The predetermined network device is a monitoring device 300B included in the wireless access network 10B in the first embodiment, a monitoring device 300A included in the wireless access network 10A in the second embodiment, and a base station in the third embodiment. 200A. In the fourth embodiment, the monitoring device 350 is a host device of the monitoring device 300A and the monitoring device 300B.

  In the following first to fourth embodiments, the radio access network 10A is configured based on LTE (Long Term Evolution) whose specifications are defined by 3GPP (Third Generation Partnership Project), and the radio access network 10B is Although an example configured based on a radio access scheme different from LTE will be described, the radio access network 10A may be configured based on a radio access scheme other than LTE.

(1) First Embodiment Hereinafter, (1.1) Outline of mobile communication system, (1.2) Detailed configuration of mobile communication system, (1.3) Operation of mobile communication system, 1.4) Description will be given in the order of the effects of the first embodiment.

(1.1) Overview of Mobile Communication System FIG. 1 is a schematic configuration diagram of a mobile communication system according to the first embodiment.

  As shown in FIG. 1, the mobile communication system according to the first embodiment includes a radio access network 10A, a radio access network 10B, and a plurality of radio terminals 100 # 1 to 100 # N. In the following description, the radio terminals 100 # 1 to 100 # N are simply referred to as the radio terminals 100 when they are not particularly distinguished.

  The radio access network 10A is configured based on LTE and is referred to as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network).

  The radio access network 10A includes a base station 200A configured to perform radio communication with the radio terminal 100, and a monitoring device 300A configured to detect a failure in the radio access network 10A. The base station 200A forms one or a plurality of cells covering a predetermined communication area range, and broadcast information (broadcast information) used for connection to the base station 200A is broadcast within the communication area range.

  The radio access network 10B is configured based on a radio access scheme different from LTE. For example, the radio access network 10B is configured based on a radio access scheme of a generation older than LTE (specifically, GSM, W-CDMA, CDMA2000, etc.). In the following description, as an example, it is assumed that the radio access network 10B is configured based on CDMA2000 1x EV-DO (hereinafter referred to as EV-DO).

  In the next generation wireless access scheme such as LTE, since the service area is limited at the beginning of the service due to the fact that base stations are sequentially added, the radio access network 10A and the radio access network 10B must coexist. Is assumed.

  The radio access network 10B includes a base station 200B configured to perform radio communication with the radio terminal 100, and a monitoring device 300B configured to detect a failure in the radio access network 10B. The base station 200B forms one or a plurality of cells that cover a predetermined communication area range, and broadcast information (broadcast information) used for connection to the base station 200B is broadcast within the communication area range. Here, it is assumed that the communication area range of base station 200B at least partially overlaps with the communication area range of base station 200A.

  In the mobile communication system according to the first embodiment, the monitoring device 300A and the monitoring device 300B are configured to be able to communicate with each other, and the monitoring device 300A and the monitoring device 300B perform fault detection in cooperation with each other.

  Each of the plurality of wireless terminals 100 is a wireless communication device possessed by the user, and is also referred to as user equipment. Each of the plurality of radio terminals 100 is configured to correspond to a plurality of radio access schemes, specifically, both LTE and EV-DO radio access schemes, and is based on broadcast information from the base station 200A. Connection to the station 200A can be attempted, and connection to the base station 200B can be attempted based on broadcast information from the base station 200B.

  In the mobile communication system configured as described above, as a result of a failure in the radio communication function of the base station 200A, the radio terminal 100 can receive broadcast information from the base station 200A, but has failed to connect to the base station 200A. Assuming that “Connection to base station 200A” includes a process for starting communication (referred to as random access) and a process for maintaining communication. Random access is a handover from a standby state (referred to as an idle state) to a communication state (referred to as a connected state or an active state) or during handover from another base station to the base station 200A. Is a process of attempting to connect to the base station 200A. In the random access procedure, even if the wireless terminal 100 repeatedly transmits a predetermined signal sequence (referred to as a random access preamble) until the maximum number of transmissions is reached, the base station cannot detect the signal sequence, and the base station May not be able to obtain a response to the wireless terminal 100. When such transmission processing of the wireless terminal 100 is executed twice, for example, the wireless terminal 100 considers that connection to the base station has failed.

  Such a connection failure is a failure that cannot be recognized by the base station 200A and the monitoring apparatus 300A included in the radio access network 10A, that is, a silent failure of the base station 200A. In the first embodiment, a mode will be described in which the monitoring device 300A and the monitoring device 300B cooperate with each other to detect a silent failure of the base station 200A.

(1.2) Detailed Configuration of Mobile Communication System Next, regarding the configuration of the mobile communication system according to the first embodiment, (1.2.1) Configuration of radio terminal, (1.2.2) Configuration of base station (1.2.3) The configuration of the monitoring device will be described in this order.

(1.2.1) Configuration of Wireless Terminal FIG. 2 is a block diagram showing the configuration of the wireless terminal 100. As shown in FIG. 2, the wireless terminal 100 includes a plurality of wireless communication units 110A and 110B, a user interface unit 120, a storage unit 130, a control unit 140, and a battery 150 provided for each of a plurality of wireless access methods. Including.

  The wireless communication unit 110A is configured based on LTE and configured to perform wireless communication with 200A included in the wireless access network 10A. The wireless communication unit 110B is configured based on EV-DO and configured to perform wireless communication with 200B included in the wireless access network 10B. Specifically, each of the wireless communication units 110A and 110B is configured using a radio frequency (RF) circuit, a baseband (BB) circuit, or the like, and transmits and receives a radio signal via an antenna and modulates a transmission signal. -Encode and demodulate / decode received signal.

  The user interface unit 120 is a display, a button, or the like that functions as an interface with the user. The storage unit 130 is configured using, for example, a memory, and stores various types of information used for controlling the wireless terminal 100 and the like. The control unit 140 is configured using, for example, a CPU, and controls various functions provided in the wireless terminal 100, specifically, the wireless communication units 110A and 110B and the user interface unit 120. The battery 150 stores power supplied to each block of the wireless terminal 100.

  In wireless terminal 100 configured as described above, control unit 140 controls wireless communication unit 110A to attempt connection to base station 200A based on broadcast information received by wireless communication unit 110A from base station 200A. In addition, when the connection to the base station 200A fails, the control unit 140 controls the wireless communication unit 110B to attempt connection to the base station 200B based on the notification information received by the wireless communication unit 110B from the base station 200B. . Then, when the connection to the base station 200B is successful, the control unit 140 controls the wireless communication unit 110B to transmit failure notification information indicating that the connection to the base station 200A has failed to the base station 200B.

(1.2.2) Configuration of Base Station FIG. 3 is a block diagram showing the configuration of the base station 200B. Since the block configuration of the base station 200A is the same as that of the base station 200B, only the block configuration of the base station 200B will be described here.

  As illustrated in FIG. 3, the base station 200B includes a wireless communication unit 210, a network communication unit 220, a storage unit 230, and a control unit 240.

  The wireless communication unit 210 is configured based on EV-DO and configured to perform wireless communication with the wireless terminal 100. Specifically, the radio communication unit 210 is configured using a radio frequency (RF) circuit, a baseband (BB) circuit, and the like, and transmits and receives radio signals via an antenna, and also modulates and encodes transmission signals. Demodulate and decode the received signal.

  The network communication unit 220 is configured to perform communication via the backhaul network (hereinafter referred to as network communication). The storage unit 230 is configured using, for example, a memory, and stores various types of information used for controlling the base station 200B. The control unit 240 is configured using, for example, a CPU, and controls various functions provided in the base station 200B, specifically, the wireless communication unit 210 and the network communication unit 220.

  In the base station 200B configured as described above, when the wireless communication unit 210 receives failure notification information indicating that the connection to the base station 200A has failed from the wireless terminal 100, the control unit 240 transmits information to a predetermined network device. The network communication unit 220 is controlled to transmit the alarm information. As described above, in the first embodiment, the predetermined network device is the monitoring device 300B.

(1.2.3) Configuration of Monitoring Device FIG. 4 is a block diagram showing the configuration of the monitoring device 300B. Since the block configuration of the monitoring device 300A is the same as that of the monitoring device 300B, only the block configuration of the monitoring device 300B will be described here.

  As illustrated in FIG. 4, the monitoring device 300 </ b> B includes a network communication unit 310, a user interface unit 320, a storage unit 330, and a control unit 340.

  The network communication unit 310 is configured to perform communication (network communication) via a backhaul network. The user interface unit 320 is a display, a keyboard, or the like that functions as an interface with the user, and is used by an operator. The storage unit 330 is configured using a memory, for example, and stores various types of information used for controlling the monitoring device 300B. The control unit 340 is configured using, for example, a CPU, and controls various functions provided in the monitoring device 300B, specifically, the network communication unit 310 and the user interface unit 320.

  In the monitoring apparatus 300B configured as described above, the network communication unit 310 receives alarm information from the base station 200B. The control unit 340 determines that a silent failure has occurred in the base station 200A when the network communication unit 310 receives a plurality of pieces of alarm information corresponding to the plurality of wireless terminals 100 within a predetermined time range. When detecting the silent failure of the base station 200A, the control unit 340 controls the network communication unit 310 so as to transmit failure notification information to that effect to the monitoring device 300A.

(1.3) Operation of Mobile Communication System Next, the operation of the mobile communication system according to the first embodiment will be described. FIG. 5 is a sequence diagram showing operations of the mobile communication system according to the first embodiment.

  As shown in FIG. 5, in step S101, a failure occurs in the wireless communication function of the base station 200A as a silent failure of the base station 200A.

  In step S102, each of the plurality of wireless terminals 100 tries to connect to the base station 200A based on the broadcast information received from the base station 200A. Specifically, each of the plurality of radio terminals 100 repeatedly transmits a random access preamble until a random access preamble response is obtained. Here, a random access preamble response is not obtained until the maximum number of transmissions is reached, and each of the plurality of wireless terminals 100 is considered to have failed to connect to the base station 200A.

  In step S103, since each of the plurality of radio terminals 100 has failed to connect to the base station 200A, the base station 200B is notified based on broadcast information from a base station 200B having a radio access method different from that of the base station 200A. Try to connect. No failure has occurred in the base station 200A, and each of the plurality of radio terminals 100 succeeds in connecting to the base station 200A.

  In step S104, each of the plurality of wireless terminals 100 transmits failure notification information indicating that the connection to the base station 200A has failed to the base station 200B. At that time, the radio terminal 100 identifies its own terminal identification information (hereinafter referred to as terminal identification information), identification information of the radio access network 10A (hereinafter referred to as network identification information), and / or identification information of the base station 200A ( Hereinafter referred to as base station identification information) and transmitted in failure notification information. The base station identification information can be obtained from broadcast information transmitted by the base station 200A. The base station 200B receives failure notification information from the plurality of wireless terminals 100.

  In step S105, the base station 200B transmits alarm information to the monitoring apparatus 300B. At that time, the base station 200B transmits the identification information included in the failure notification information included in the alarm information. Monitoring device 300B receives alarm information from base station 200B. When monitoring apparatus 300B receives the first alarm information in step S105 # 1, it starts a timer for measuring a predetermined time range.

  In step S106, the monitoring apparatus 300B counts alarm information from the base station 200B, and confirms whether the count value for the base station 200A is equal to or greater than a predetermined threshold value. Specifically, the monitoring apparatus 300B refers to the terminal identification information included in the alarm information, and does not count the second and subsequent alarm information corresponding to the same terminal. This is because it is necessary to confirm that a connection failure has occurred in many wireless terminals 100 because the cause of the connection failure may be a malfunction of the wireless terminal 100. In addition, the monitoring apparatus 300B refers to the network identification information and / or base station identification information included in the alarm information, and performs counting for the same base station. Furthermore, the monitoring device 300B refers to the timer and resets the count value when the predetermined time range expires.

  When the count value for base station 200A is equal to or greater than a predetermined threshold, monitoring device 300B determines that a silent failure has occurred in base station 200A.

  In step S107, the monitoring device 300B transmits failure notification information indicating that a silent failure has occurred in the base station 200A to the monitoring device 300A. At that time, the monitoring apparatus 300B transmits the base station identification information of the base station 200A included in the failure notification information. The monitoring device 300A receives the failure notification information.

  In step S108, failure handling processing is performed. As the failure handling process, first, the monitoring apparatus 300A instructs the base station 200A to perform autonomous recovery. As a result of the instruction, when the autonomous recovery cannot be performed, the base station 200A stops transmission of broadcast information used for connection to the base station 200A. Alternatively, the base station 200A transmits connection restriction information for restricting connection to the base station 200A included in broadcast information used for connection to the base station 200A. Thereby, it is possible to prevent the wireless terminal 100 from trying to connect to the base station 200A. Furthermore, monitoring device 300A or monitoring device 300B instructs base station 200B to expand the communication area range of base station 200B in order to supplement the communication area range of base station 200A. In this case, it is assumed that there is no other base station (hereinafter simply referred to as “another base station”) having the same radio access scheme as base station 200B in the communication area of base station 200A. That is, the condition is that the communication area range of the another base station does not overlap with the communication area range of the base station 200A. The base station 200B performs processing for expanding the communication area range of the own station. As processing for expanding the communication area range, processing such as increasing the transmission power of the base station 200B, changing the antenna tilt angle of the base station 200B, or increasing the transmission directivity in the direction of the base station 200A. Is possible. Note that if the another base station is within the communication area of the base station 200A, the radio terminal 100 connects to the other base station. In this case, the monitoring apparatus 300A or the monitoring apparatus 300B does not instruct the base station 200B for the base station 200B to supplement the communication area range of the base station 200A.

(1.4) Effects of First Embodiment As described above, according to the first embodiment, focusing on the property that communication area ranges of networks with different wireless access methods often overlap each other, wireless access A silent failure of the base station 200A included in the network 10A can be detected via the base station 200B included in the radio access network 10B.

  In the first embodiment, since the wireless terminal 100 transmits the identification information of the wireless access network 10A and / or the base station 200A in the failure notification information, it is possible to perform detailed failure analysis on the network side. , Can contribute to avoiding deterioration of service quality.

  Furthermore, in the first embodiment, the monitoring apparatus 300B determines that a silent failure has occurred in the base station 200A when a plurality of alarm information corresponding to the plurality of wireless terminals 100 is obtained within a predetermined time range. To do. Since it is assumed that the wireless terminal 100 is the cause of the connection failure to the base station 200A, the silent failure of the base station 200A is detected by obtaining a plurality of alarm information corresponding to the plurality of wireless terminals 100. By doing so, the detection accuracy of silent failure can be improved.

  In the first embodiment, after detecting a silent failure of the base station 200A, the base station 200A stops transmitting broadcast information used for connection to the base station 200A. Alternatively, after the silent failure is detected, the base station 200A transmits connection restriction information for restricting connection to the base station 200A in broadcast information used for connection to the base station 200A. As a result, the wireless terminal 100 does not attempt to connect to the base station 200A, and it is possible to avoid occurrence of useless processing, so that it is possible to avoid deterioration in service quality.

  In the first embodiment, after the silent failure is detected, the base station 200B performs a process of expanding the communication area range of the own station. Thereby, since the communication area range of the base station 200A can be complemented using the base station 200B, it is possible to avoid deterioration in service quality.

(2) Second Embodiment In the second embodiment, the predetermined network device is the monitoring device 300A. In the second embodiment, differences from the first embodiment will be described, and redundant description will be omitted. Hereinafter, (2.1) Outline of the mobile communication system and (2.2) Operation of the mobile communication system will be described in this order.

(2.1) Overview of Mobile Communication System FIG. 6 is a schematic configuration diagram of a mobile communication system according to the second embodiment.

  As shown in FIG. 6, in the mobile communication system according to the second embodiment, the monitoring device 300A and the base station 200B are configured to be able to communicate with each other, and the monitoring device 300A and the base station 200B cooperate with each other to detect a failure. I do. In contrast, the monitoring device 300A and the monitoring device 300B are not configured to communicate with each other.

  Other system configurations are the same as those in the first embodiment.

(2.2) Operation of Mobile Communication System FIG. 7 is a sequence diagram showing the operation of the mobile communication system according to the second embodiment.

  As shown in FIG. 7, the processes in steps S201 to S204 are the same as in the first embodiment.

  In step S205, the base station 200B transmits alarm information to the monitoring apparatus 300A. At that time, the base station 200B transmits the identification information included in the failure notification information included in the alarm information. Monitoring device 300A receives alarm information from base station 200B. When monitoring device 300A receives the first alarm information in step S205 # 1, it starts a timer for measuring a predetermined time range.

  In step S206, monitoring apparatus 300A counts alarm information from base station 200B, and checks whether the count value for base station 200A is equal to or greater than a predetermined threshold. Specifically, the monitoring apparatus 300A refers to the terminal identification information included in the alarm information, and does not count the second and subsequent alarm information corresponding to the same terminal. In addition, the monitoring apparatus 300A refers to the network identification information and / or base station identification information included in the alarm information, and performs counting for the same base station. Furthermore, the monitoring device 300A refers to the timer and resets the count value when the predetermined time range expires.

  When the count value for base station 200A is equal to or greater than a predetermined threshold, monitoring device 300A determines that a silent failure has occurred in base station 200A.

  In step S208, failure handling processing is performed. As the failure handling processing, processing similar to the processing described in the first embodiment can be applied.

(3) Third Embodiment In the third embodiment, the predetermined network device is the base station 200A. In the third embodiment, differences from the first embodiment will be described, and redundant description will be omitted. Hereinafter, (3.1) Outline of mobile communication system and (3.2) Operation of mobile communication system will be described in this order.

(3.1) Overview of Mobile Communication System FIG. 8 is a schematic configuration diagram of a mobile communication system according to the third embodiment.

  As shown in FIG. 8, in the mobile communication system according to the third embodiment, the base station 200A and the base station 200B are configured to communicate with each other, and the base station 200A and the base station 200B cooperate with each other to detect a failure. I do. In contrast, the monitoring device 300A and the monitoring device 300B are not configured to communicate with each other.

  Other system configurations are the same as those in the first embodiment.

(3.2) Operation of Mobile Communication System FIG. 9 is a sequence diagram showing the operation of the mobile communication system according to the third embodiment.

  As shown in FIG. 9, the processes in steps S301 to S304 are the same as in the first embodiment.

  In step S305, the base station 200B transmits alarm information to the base station 200A. At that time, the base station 200B transmits the identification information included in the failure notification information included in the alarm information. Base station 200A receives alarm information from base station 200B. When the base station 200A receives the first alarm information in step S305 # 1, the base station 200A starts a timer for measuring a predetermined time range.

  In step S306, the base station 200A transmits alarm information to the monitoring apparatus 300A. At that time, the base station 200A transmits the identification information included in the alarm information from the base station 200B in the alarm information to the monitoring device 300A. Monitoring device 300A receives alarm information from base station 200A. When monitoring apparatus 300A receives the first alarm information in step S306 # 1, it starts a timer for measuring a predetermined time range.

  In step S307, the base station 200A counts the alarm information from the base station 200B, and confirms whether the count value for the base station 200A is equal to or greater than a predetermined threshold value. Specifically, the base station 200A refers to the terminal identification information included in the alarm information and does not count the second and subsequent alarm information corresponding to the same terminal. Further, the base station 200A refers to the network identification information and / or the base station identification information included in the alarm information, and performs counting for the same base station. Furthermore, the base station 200A refers to the timer and resets the count value when the predetermined time range expires. When the count value for the base station 200A is equal to or greater than a predetermined threshold, the base station 200A determines that a silent failure has occurred in itself.

  In step S308, monitoring apparatus 300A counts alarm information from base station 200A, and checks whether the count value for base station 200A is equal to or greater than a predetermined threshold. Specifically, the monitoring apparatus 300A refers to the terminal identification information included in the alarm information, and does not count the second and subsequent alarm information corresponding to the same terminal. In addition, the monitoring apparatus 300A refers to the network identification information and / or base station identification information included in the alarm information, and performs counting for the same base station. Furthermore, the monitoring device 300A refers to the timer and resets the count value when the predetermined time range expires. When the count value for base station 200A is equal to or greater than a predetermined threshold, monitoring device 300A determines that a silent failure has occurred in base station 200A.

  In step S309, failure handling processing is performed. As the failure handling processing, processing similar to the processing described in the first embodiment can be applied.

  Note that in this sequence, an example in which both the base station 200A and the monitoring device 300A detect a silent failure has been described. However, one of the base station 200A and the monitoring device 300A may detect the silent failure, and the detection result May be notified to the other.

(4) Fourth Embodiment In the fourth embodiment, the predetermined network device is the upper monitoring device 350. In the fourth embodiment, differences from the first embodiment will be described, and redundant description will be omitted. Hereinafter, (4.1) Outline of mobile communication system and (4.2) Operation of mobile communication system will be described in this order.

(4.1) Overview of Mobile Communication System FIG. 10 is a schematic configuration diagram of a mobile communication system according to the fourth embodiment.

  As illustrated in FIG. 10, the mobile communication system according to the fourth embodiment further includes upper monitoring devices 350 of the monitoring device 300A and the monitoring device 300B. The monitoring device 350 is an independent monitoring device that does not belong to either the wireless access network 10A or the wireless access network 10B, and is configured to be able to communicate with each of the monitoring device 300A and the monitoring device 300B. In contrast, the monitoring device 300A and the monitoring device 300B are not configured to communicate with each other.

  Other system configurations are the same as those in the first embodiment.

(4.2) Operation of Mobile Communication System FIG. 11 is a sequence diagram showing the operation of the mobile communication system according to the fourth embodiment.

  As shown in FIG. 11, the processes in steps S401 to S404 are the same as in the first embodiment.

  In step S405, the base station 200B transmits alarm information to the monitoring apparatus 300B. At that time, the base station 200B transmits the identification information included in the failure notification information included in the alarm information. Monitoring device 300B receives alarm information from base station 200B.

  In step S406, the monitoring device 300B transmits alarm information to the monitoring device 350. At that time, the monitoring apparatus 300B transmits the identification information included in the alarm information from the base station 200B in the alarm information to the monitoring apparatus 350. The monitoring device 350 receives alarm information from the monitoring device 300B. When monitoring device 350 receives the first alarm information in step S406 # 1, it starts a timer for measuring a predetermined time range.

  In step S407, the monitoring device 350 counts alarm information from the monitoring device 300B, and confirms whether or not the count value for the base station 200A is equal to or greater than a predetermined threshold value. Specifically, the monitoring device 350 refers to the terminal identification information included in the alarm information and does not count the second and subsequent alarm information corresponding to the same terminal. Further, the monitoring device 350 refers to the network identification information and / or base station identification information included in the alarm information, and performs counting for the same base station. Furthermore, the monitoring device 350 refers to the timer and resets the count value when the predetermined time range expires.

  When the count value for the base station 200A is equal to or greater than a predetermined threshold, the monitoring device 350 determines that a silent failure has occurred in the base station 200A.

  In step S408, the monitoring device 350 transmits failure notification information indicating that a silent failure has occurred in the base station 200A to the monitoring device 300A. At that time, the monitoring device 350 transmits the base station identification information of the base station 200A included in the failure notification information. The monitoring device 300A receives the failure notification information.

  In step S409, failure handling processing is performed. As the failure handling processing, processing similar to the processing described in the first embodiment can be applied.

(5) Other Embodiments As described above, the present invention has been described according to each embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In each of the embodiments described above, the radio access network 10A is configured based on LTE and the radio access network 10B is configured based on EV-DO. However, the radio access network 10B is a radio access scheme other than cellular. For example, it may be configured based on wireless LAN (IEEE 802.11) or WiMAX (IEEE 802.16). Further, not only when the radio access network 10A is configured based on LTE, but the radio access network 10A is configured based on W-CDMA or CDMA2000, and the radio access network 10B is configured based on LTE. Good.

  In each of the above-described embodiments, the random access failure has been described as an example of the connection failure to the base station 200A. However, the connection failure to the base station 200A is not limited to the random access failure, but the radio link disconnection (RLF) is also a connection failure. include. The disconnection of the radio link means that the radio link is disconnected due to deterioration of the radio state or the like once the radio link with the base station 200A is established. In this case, the radio terminal 100 preferably transmits information indicating the type of failure of connection to the base station 200A included in the failure notification information. That is, when the wireless terminal 100 fails to connect to the base station 200A, the wireless terminal 100 includes failure type information indicating whether the type is random access failure or wireless link disconnection in the failure notification information. Receiving the failure notification information, the base station 200B transmits the failure type information included in the failure notification information included in the alarm information. As a result, the alarm information receiving side can perform more detailed failure analysis, which can contribute to avoiding deterioration in service quality.

  In each embodiment described above, it has been described that the monitoring apparatus 300A monitors the base station 200A and the monitoring apparatus 300B monitors the base station 200B. However, the monitoring apparatus has a function of monitoring each of the base station 200A and the base station 200B. You may prepare. Thereby, base station 200A and base station 200B can be monitored with one monitoring apparatus.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

  10A, 10B ... wireless access network, 100 ... wireless terminal, 110A, 110B ... wireless communication unit, 120 ... user interface unit, 130 ... storage unit, 140 ... control unit, 150 ... battery, 200A, 200B ... base station, 210 ... Wireless communication unit 220 ... Network communication unit 230 ... Storage unit 240 ... Control unit 300A, 300B, 350 ... Monitoring device 310 ... Network communication unit 320 ... User interface unit 330 ... Storage unit 340 ... Control unit

Claims (15)

After a wireless terminal corresponding to a plurality of wireless access methods fails to connect to a first base station included in the first network, the wireless terminal is included in a second network having a different wireless access method from the first network. Transmitting failure notification information indicating failure in connection to the first base station to the second base station to be connected;
When the second base station receives failure notification information from the wireless terminal, transmitting alarm information to a predetermined network device;
The predetermined network device, based on alarm information from the second base station, detecting a specific failure that is a failure of the first base station and is difficult to detect in the first network;
Fault detection method including   The failure detection method according to claim 1, wherein the predetermined network device is a monitoring device included in the second network.   The failure detection method according to claim 1, wherein the predetermined network device is a monitoring device included in the first network.   The failure detection method according to claim 1, wherein the predetermined network device is the first base station.   The failure detection method according to claim 1, wherein the predetermined network device is a higher-level monitoring device of each of a monitoring device included in the first network and a monitoring device included in the second network.   As a result of trying to connect to the first base station based on the broadcast information received from the first base station, the wireless terminal fails to connect to the first base station, and then transmits the failure notification. The failure detection method according to claim 1, wherein information is transmitted to the second base station. The wireless terminal includes identification information of the first network and / or identification information of the first base station included in the failure notification information and transmits,
The failure detection method according to any one of claims 1 to 6, wherein the second base station transmits the identification information included in the failure notification information from the wireless terminal in the alarm information. The wireless terminal transmits information indicating the type of failure of connection to the first base station included in the failure notification information,
The failure detection method according to any one of claims 1 to 7, wherein the type of connection failure includes random access failure or radio link disconnection.   The predetermined network device determines that the specific failure has occurred in the first base station when a plurality of alarm information corresponding to a plurality of wireless terminals is obtained within a predetermined time range; The failure detection method according to any one of claims 1 to 8.   The failure detection method according to any one of claims 1 to 9, wherein at least a part of the communication area range of the first base station and the communication area range of the second base station overlap each other.   The said 1st base station stops transmission of the alerting | reporting information used for the connection to a said 1st base station after the said specific failure is detected, It is any one of Claims 1-10. The failure detection method according to claim 1.   After the specific failure is detected, the first base station broadcasts connection restriction information for restricting connection to the first base station used for connection to the first base station. The failure detection method according to claim 1, wherein the failure detection method is transmitted by being included in information.   The said 2nd base station is a process as described in any one of Claims 1-12 which performs the process which expands the communication area range of an own station after the said specific failure is detected. Fault detection method. A plurality of wireless communication units provided for each of a plurality of wireless access methods;
A control unit for controlling the plurality of wireless communication units;
With
After the controller fails to connect to the first base station included in the first network, the control unit sends the second base station included in the second network different in radio access method from the first network. On the other hand, a wireless terminal that controls the plurality of wireless communication units so as to transmit failure notification information indicating that the connection to the first base station has failed. A base station included in a second network having a different radio access method from the first network,
A wireless communication unit for performing wireless communication;
A network communication unit for performing network communication;
A control unit for controlling the wireless communication unit and the network communication unit;
With
When the wireless communication unit receives failure notification information indicating that the connection to the first base station included in the first network has failed from wireless terminals compatible with a plurality of wireless access methods. A base station that controls the network communication unit to transmit alarm information to a predetermined network device.

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