Quality monitoring system, quality monitoring apparatus, and quality monitoring method in wireless communication network

A mobile terminal includes a measuring unit that measures at least the moving speed of the self terminal and communication quality of wireless communication, and a communication unit that transmits terminal information including moving speed information and communication quality information. A quality monitoring apparatus (90) includes a terminal information collection unit (901) that collects the terminal information from at least one mobile terminal, and a terminal information classification unit (903) and a quality analyzing unit (904) that monitor communication quality in a predetermined target area for each moving speed range of the mobile terminal based on the collected terminal information.

This application is the National Phase of PCT/JP2009/064851, filed Aug. 26, 2009, which is based upon and claims the benefit of priority from Japanese patent application No. 2008-291841, filed on Nov. 14, 2008, the disclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present invention relates to a quality monitoring system in a wireless communication network and, more particularly, to a quality monitoring system, a quality monitoring apparatus, and a quality monitoring method in a wireless communication network, which can monitor communication quality for each moving speed range of a mobile terminal.

BACKGROUND ART

In a wireless communication network, generally, a call processing log is stored in a network-side communication apparatus, and quality monitoring is performed based on a communication quality index value calculated from the log.

As an example, the wireless base station control apparatus of a mobile communication network based on the specifications of 3GPP (3rd Generation Partnership Program) measures and records the attempt and failure counts of radio access bearer establishment, handover, and the like for each wireless cell as a call processing log to be transmitted/received to/from a mobile terminal on the control plane, as defined in reference “3GPP TS 32.403, “Telecommunication management; Performance management (PM); Performance measurements—UMTS and combined UMTS/GSM (Release 7)”, 2005” (to be referred to as reference 1 hereinafter). The wireless base station control apparatus obtains KPI (Key Performance Indicator) values such as a radio access bearer establishment failure rate and a handover failure rate, which are defined in reference “3GPP TS 32.410, “Telecommunication management; Key Performance Indicators (KPI) for UMTS and GSM (Release 8)”, 2008” (to be referred to as reference 2 hereinafter), from the measured values and uses them for quality monitoring.

Another technique is also known, which causes not the network-side communication apparatus but a mobile terminal to measure quality information and causes a server to collect the quality information by transmission on the user plane and monitor communication quality.

For example, a system disclosed in Japanese Patent Laid-Open No. 2008-109571 statistically processes network quality information collected from mobile terminals for each unit area, calculates quality statistics in each unit area, and uses them for quality monitoring.

There is also known a technique of causing a mobile terminal to control communication quality. For example, a mobile communication system disclosed in Japanese Patent Laid-Open No. 2008-092421 causes a mobile terminal to detect the moving speed of its own and determine a communication data format for wireless communication with a wireless base station based on the detected moving speed.

DISCLOSURE OF INVENTION

Problems to be Solved by the Invention

In general, when designing wireless areas by, for example, setting wireless base station installation points and adjusting their antenna tilt angles, communication quality can sometimes be improved by optimizing the wireless areas in consideration of user's moving characteristic therein. For example, a cellular mobile communication network maintains communication by handover when a user moves through wireless cells. The overlap areas between the wireless cells where handover is executed are designed based on the moving speed distributions of users who move near those areas. On, for example, a national road where many users move at high speed, it is necessary to ensure extra overlap areas between the wireless cells not to cause handover delay.

However, the quality monitoring systems disclosed in reference 1, reference 2, and Japanese Patent Laid-Open No. 2008-109571 cannot confirm the relationship between the user's moving speed and the communication quality. For this reason, it is impossible to determine whether wireless area design is appropriately done according to the user's moving characteristic. That is, none of the techniques disclosed in reference 1, reference 2, and Japanese Patent Laid-Open No. 2008-109571 takes the speed of a mobile terminal into consideration when calculating quality statistics. Hence, when communication quality has degraded, whether the degradation in the communication quality has occurred due to the user's moving characteristic cannot be determined.

On the other hand, the system disclosed in Japanese Patent Laid-Open No. 2008-092421 considers the variation in the communication quality caused by the movement of a mobile terminal. The system disclosed in Japanese Patent Laid-Open No. 2008-092421 however assumes to define the correspondence between communication quality and the moving speed of a mobile terminal in advance and use the predefined relationship. More specifically, the system disclosed in Japanese Patent Laid-Open No. 2008-092421 causes the mobile terminal to store in advance the relationship between the communication data format and the moving speed of the mobile terminal and determine the communication data format based on the measured moving speed of its own. For this reason, the system disclosed in Japanese Patent Laid-Open No. 2008-092421 cannot monitor the correspondence between the communication quality and the moving speed of the mobile terminal for each wireless area, and therefore cannot determine whether wireless area design of, for example, the overlap areas between the wireless cells is appropriately done in consideration of the user's moving characteristic in the wireless areas.

The present invention has been made in consideration of the above-described problems, and has as its exemplary object to allow a quality monitoring system in a wireless communication network to monitor the correspondence between communication quality and the moving speed of a mobile terminal for each area.

Means of Solution to the Problems

A quality monitoring system in a wireless communication network according to an exemplary aspect of the invention includes at least one mobile terminal, and a quality monitoring apparatus, the mobile terminal including measuring means for measuring at least a moving speed of a self terminal and communication quality of wireless communication, and communication means for transmitting terminal information including moving speed information and communication quality information, and the quality monitoring apparatus including terminal information collection means for collecting the terminal information from the at least one mobile terminal, and analyzing means for monitoring communication quality in a predetermined target area for each moving speed range of the mobile terminal based on the collected terminal information.

A quality monitoring apparatus in a wireless communication network according to an exemplary aspect of the invention includes terminal information collection means for collecting, from at least one mobile terminal, terminal information including at least moving speed information and communication quality information, and analyzing means for monitoring communication quality in a predetermined target area for each moving speed range of the mobile terminal based on the collected terminal information.

A quality monitoring method in a wireless communication network according to an exemplary aspect of the invention includes the measuring procedure of causing at least one mobile terminal to measure at least a moving speed of a self terminal and communication quality of wireless communication, the transmission procedure of causing the mobile terminal to transmit terminal information including moving speed information and communication quality information, the terminal information collection procedure of causing a quality monitoring apparatus. to collect the terminal information from the at least one mobile terminal, and the analyzing procedure of causing the quality monitoring apparatus to monitor communication quality in a predetermined target area for each moving speed range of the mobile terminal based on the collected terminal information.

Effects of the Invention

According to the present invention, terminal information is classified by the moving speed range, and quality statistics specific to each moving speed range are obtained. This enables to grasp the relationship between the communication quality and the moving speed of the mobile terminal. It is therefore possible to determine, when communication quality has degraded, whether the degradation in the communication quality has occurred due to the user's moving characteristic in that area. In addition, the correspondence between the communication quality and the moving speed of the mobile terminal changes depending on whether the wireless area design of the overlap areas between wireless cells and the like is appropriately done. In the present invention, the correspondence between the communication quality and the moving speed of the mobile terminal can be analyzed based on the terminal information collected from the mobile terminal. According to the present invention, it is consequently possible to determine whether wireless area design is appropriately done according to the user's moving characteristic in the area.

BEST MODE FOR CARRYING OUT THE INVENTION

The first exemplary embodiment to practice the present invention will be described in detail with reference to the accompanying drawings.FIG. 1is a block diagram showing the arrangement of a mobile communication network according to the first exemplary embodiment of the present invention. A mobile terminal1has a wireless communication function, and includes a measuring unit2configured to measure at least the moving speed of the self terminal and the communication quality of wireless communication, and a communication unit3configured to transmit terminal information including moving speed information and communication quality information.

The measuring unit2measures the moving speed of the self terminal. The moving speed can be measured by a general speed sensor and acceleration sensor. It is also possible to measure the position of the self terminal using, for example, a GPS (Global Positioning System) and obtain the moving speed of the self terminal by time derivative of the position.

The measuring unit2also measures the communication quality of wireless communication. The items of communication quality include a communication type such as voice communication, packet communication, or streaming communication, a call processing type such as radio access bearer establishment/release or handover, a call processing success/failure type, a packet transfer throughput, and a packet transfer delay.

The communication unit3transmits, to a quality monitoring apparatus4, terminal information including the information of the moving speed and the information of the communication quality measured by the measuring unit2. A wireless base station (not shown) for relaying communication, a mobile communication core network (not shown), and the like may exist between the mobile terminal1and the quality monitoring apparatus4, as a matter of course. When transmitting the terminal information, the communication unit3may add terminal identification information to identify the self terminal to the terminal information.

The quality monitoring apparatus4includes a terminal information collection unit5configured to collect the terminal information transmitted from the mobile terminal1, and an analyzing unit6configured to monitor communication quality in a predetermined target area for each moving speed range of the mobile terminal based on the collected terminal information. Note thatFIG. 1illustrates only one mobile terminal1for the descriptive convenience. In fact, the system can target a plurality of mobile terminals1that are present in the area.

The quality monitoring operation of the mobile communication network according to the first exemplary embodiment will be described next with reference to the flowchart ofFIG. 2.

The measuring unit2of the mobile terminal1measures the moving speed of the self terminal and the communication quality of wireless communication (step S1).

The communication unit3of the mobile terminal1transmits terminal information including the moving speed information and the communication quality information to the quality monitoring apparatus4(step S2).

The terminal information collection unit5of the quality monitoring apparatus4collects the terminal information transmitted from the mobile terminal1(step S3).

The analyzing unit6of the quality monitoring apparatus4acquires the terminal information of each mobile terminal that exists in a predetermined target area from the10; terminal information collected by the terminal information collection unit5, classifies the pieces of acquired terminal information by the moving speed range, and obtains quality statistics specific to each moving speed range (step S4). The moving speed ranges mean divided moving speed ranges of, for example, 0 km/h (inclusive) to 5 km/h (exclusive), 5 km/h (inclusive) to 20 km/h (exclusive), 20 km/h (inclusive) to 60 km/h (exclusive), 60 km/h (inclusive) to 100 km/h (exclusive), and 100 km/h or more. The predetermined target area can be a wireless cell that is the communication service providing range of a wireless base station, a specific prefecture or municipality, a specific rectangular area, or the like.

Finally, the analyzing unit6outputs the quality analysis result via an output device such as a display and ends the quality analysis processing (step S5).

As described above, in the first exemplary embodiment of the present invention, terminal information is classified by the moving speed of a mobile terminal, and quality statistics specific to each moving speed range are obtained. This allows to grasp the relationship between the communication quality and the moving speed of the mobile terminal. It is therefore possible to determine, when communication quality has degraded, whether the degradation in the communication quality has occurred due to the user's moving characteristic in that area.

Additionally, in the first exemplary embodiment of the present invention, the correspondence between the communication quality and the moving speed of the mobile terminal is assumed to change depending on the wireless area. It is therefore possible to analyze the correspondence between the communication quality and the moving speed of the mobile terminal for each wireless area based on the terminal information collected from the mobile terminal. That is, the first exemplary embodiment of the present invention makes it possible to monitor the correspondence between the communication quality and the moving speed of the mobile terminal for each area considering that the correspondence between the communication quality and the moving speed of the mobile terminal changes depending on whether the wireless area design of the overlap areas between wireless cells and the like is appropriately done.

On the other hand, the system disclosed in Japanese Patent Laid-Open No. 2008-092421 does not analyze moving speed specific quality statistics for each area. That is, the system disclosed in Japanese Patent Laid-Open No. 2008-092421 assumes to fix the correspondence between communication quality and the moving speed of a mobile terminal independently of the area and use the predefined correspondence. For this reason, the system disclosed in Japanese Patent Laid-Open No. 2008-092421 cannot monitor the correspondence between the communication quality and the moving speed of the mobile terminal for each wireless area, and therefore cannot determine whether wireless area design is appropriately done according to the user's moving characteristic in the areas.

The second exemplary embodiment to practice the present invention will be described next in detail with reference to the accompanying drawings. In the second exemplary embodiment, the first exemplary embodiment will be described in more detail, and the first exemplary embodiment is applied to a cellular mobile communication network. However, the present invention is not limited to the cellular mobile communication network and is also applicable to other wireless communication networks such as a wireless LAN (Local Area Network) and a WiMAX (Worldwide. Interoperability for Microwave Access) network.

FIG. 3is a block diagram showing the arrangement of a mobile communication network according to the second exemplary embodiment of the present invention. A wireless cell10is the communication service providing range of a wireless base station20. A wireless cell11is the communication service providing range of a wireless base station21. A mobile terminal30existing in the wireless cell10communicates with the wireless base station20via a wireless link40. When the mobile terminal30moves from the wireless cell10to the wireless cell11during the communication, handover is executed in an overlap area50between the wireless cell10and the wireless cell11so that the mobile terminal30is connected to the wireless base station21via a wireless link41.

A wireless base station control apparatus60is connected to the subordinate wireless base stations20and21via wired links70and71, respectively, to transmit/receive communication traffic and control traffic to/from the wireless base stations20and21. The wireless base station control apparatus60is also connected to a mobile communication core network80via a wired link72to transmit/receive communication traffic and control traffic.

A quality monitoring apparatus90is connected to the mobile communication core network80via a wired link73to collect terminal information transmitted from the mobile terminal30and monitor communication quality. Note that the quality monitoring apparatus90may be connected to the wireless base station control apparatus60or an external network (not shown) to collect terminal information from the mobile terminal30via the wireless base station control apparatus60or the external network.

The arrangements of the mobile terminal30and the quality monitoring apparatus90according to the second exemplary embodiment will be described next. Note that the remaining constituent elements inFIG. 3are not directly relevant to the present invention, and a detailed description thereof will be omitted.

The arrangement of the mobile terminal30will be described with reference toFIG. 4. The mobile terminal30includes a positioning unit301configured to measure the position of the self terminal, a speed measuring unit302configured to measure the moving speed of the self terminal, a quality measuring unit303configured to measure the communication quality of wireless communication, a measurement information storage unit304configured to store the measurement information measured by the positioning unit301, the speed measuring unit302, and the quality measuring unit303, and a communication unit305configured to connect the terminal to a wireless base station via a wireless link. The positioning unit301, the speed measuring unit302, and the quality measuring unit303constitute a measuring means corresponding to the measuring unit2inFIG. 1.

The positioning unit301measures the position of the self terminal using a GPS, or obtains the position of the self terminal by calculation based on the positions of a plurality of wireless base stations and the time lag between radio waves arriving from those wireless base stations.

The speed measuring unit302measures the moving speed of the self terminal by a general speed sensor and acceleration sensor or time derivative of the position measured by the positioning unit301.

The quality measuring unit303measures communication quality. Items to be measured by the quality measuring unit303include a communication type such as voice communication, packet communication, or streaming communication, a call processing type such as radio access bearer establishment/release or handover, a success/failure type representing whether call processing such as radio access bearer establishment/release or handover has normally ended, a packet transfer throughput, and a packet transfer delay.

The measurement information storage unit304serves as a means for storing the pieces of measurement information obtained by the positioning unit301, the speed measuring unit302, and the quality measuring unit303in association with each other. More specifically, the measurement information storage unit304acquires the position and moving speed at the time of quality measurement by the quality measuring unit303from the positioning unit301and the speed measuring unit302, and stores the position and moving speed in association with quality information measured by the quality measuring unit303. Note that as the position and moving speed, the average values for N sec from the start of communication, the average values for N sec before the end of communication, the average values from the start to the end of communication, the average values for N sec immediately before or immediately after occurrence of a call processing event such as handover, or the like can be used. Normally, the average values of the position and moving speed measured by the positioning unit301and the speed measuring unit302for N sec before the end of communication are adopted as the values of the position and moving speed.

The communication unit305serves as a means for connecting the terminal to a wireless base station via a wireless link to perform wireless communication. The communication unit305transmits, to the quality monitoring apparatus90, terminal information including the information stored in the measurement information storage unit304and a scrambling code received from the wireless base station. The terminal information transmission time can be set to a predetermined period, a time designated by the terminal user, the communication end time, the time immediately after handover, or a time designated by the quality monitoring apparatus90. When transmitting the terminal information, the communication unit305may add terminal identification information to identify the self terminal to the terminal information.

The arrangement of the quality monitoring apparatus90will be described next with reference toFIG. 5. The quality monitoring apparatus90includes a terminal information collection unit901configured to collect terminal information transmitted from the mobile terminal30, a terminal information storage unit902configured to store the collected terminal information, a terminal information classification unit903configured to classify the terminal information by the moving speed range of the mobile terminal30, a quality analyzing unit904configured to totalize the terminal information for each moving speed range and obtain quality statistics specific to each moving speed range, an input unit905configured to input a quality analysis instruction and conditions for quality analysis, and an output unit906configured to output the quality analysis result of the quality analyzing unit904. The terminal information storage unit902, the terminal information classification unit903, the quality analyzing unit904, the input unit905, and the output unit906constitute an analyzing means corresponding to the analyzing unit6inFIG. 1.

FIG. 6shows an example of terminal information stored in the terminal information storage unit902. In the example ofFIG. 6, the terminal information storage unit902stores, as terminal information, the date/time of terminal information measurement in the mobile terminal, position information, a scrambling code, a moving speed, a communication type (for example, streaming, packet, or voice), a call processing type (for example, radio access bearer establishment, radio access bearer release, or handover), and a call processing success/failure type.

As the position information, not only the latitude and longitude but also horizontal rectangular coordinates or an address may be used. In a mobile communication network complying with the 3GPP specifications, the scrambling code is broadcast in a wireless cell via a BCH (Broadcast Channel). When combined with a location area code or a routing area code, the scrambling code can be used as position information to uniquely identify the wireless cell where the mobile terminal30exists.

FIG. 7shows another example of terminal information stored in the terminal information storage unit902. In the example ofFIG. 7, the terminal information storage unit902stores, as terminal information, a packet throughput and a packet transfer delay upon packet communication in addition to the date/time of terminal information measurement in the mobile terminal, position information, a scrambling code, and a moving speed.

The operation of the quality monitoring apparatus90according to the second exemplary embodiment will be described next with reference to the flowchart ofFIG. 8.

The terminal information collection unit901of the quality monitoring apparatus90collects terminal information from the mobile terminal30existing in the mobile communication network (step S101). Note thatFIG. 3illustrates only one mobile terminal30for the descriptive convenience. In fact, the system can target a plurality of mobile terminals30that are present in the area. As described above, the terminal information transmission time can be set to a predetermined period, a time designated by the terminal user, the communication end time, the time immediately after handover, or a time designated by the quality monitoring apparatus90. This setting can be done by terminal information collection unit901for the mobile terminal30. The terminal information collection unit901may collect terminal information from only mobile terminals existing in a specific area (for example, a specific wireless cell, an area under a specific wireless base station control apparatus, a specific prefecture or municipality, or a specific rectangular area).

The terminal information storage unit902stores the terminal information collected by the terminal information collection unit901.

Next, the operator of the quality monitoring apparatus90inputs conditions for quality analysis (quality analysis conditions) via the input unit905(step S102). The quality analysis conditions include the moving speed range, the target area, and the target period. For example, as the moving speed range, a range of 0 km/h (inclusive) to 5 km/h (exclusive), 5 km/h (inclusive) to 20 km/h (exclusive), 20 km/h (inclusive) to 60 km/h (exclusive), 60 km/h (inclusive) to 100 km/h (exclusive), or 100 km/h or more is designated. As the target area, a specific wireless cell, an area under the specific wireless base station control apparatus60, a specific prefecture or municipality, or a specific rectangular area is designated. As the target period, the range of measurement date/time of terminal information to be analyzed is designated.

Next, the terminal information classification unit903acquires terminal information in the target area and target period from the terminal information storage unit902in accordance with the quality analysis conditions input from the input unit905, and classifies the acquired terminal information by the moving speed range based on the moving speed information included in the terminal information (step S103).

Next, the quality analyzing unit904receives the terminal information classified by the moving speed ramie from the terminal information classification unit903, and obtains quality statistics for the moving speed range from the terminal information (step S104).

Finally, the output unit906outputs the quality analysis result of the quality analyzing unit904via an output device such as a display and ends the quality analysis processing (step S105).

FIG. 9shows an example of quality analysis result output by the output unit906.FIG. 9illustrates a screen that displays the quality analysis result. A screen907displays a target area9071, a target period9072, and moving speed ranges9073input as the quality analysis conditions. The screen907also displays handover attempt counts9074classified by the moving speed range, and handover failure counts9075classified by the moving speed range. The screen907also displays handover failure rates9076which are calculated as quality statistics for the respective moving speed ranges by dividing the handover failure counts for the moving speed ranges by the handover attempt counts for the moving speed ranges. The screen907displays, on the lower side, a time series graph9077that calculates the handover failure rate in days during the target period for each moving speed range.

Note that in the example ofFIG. 9, the handover failure rate is used as an example of the quality statistics. However, the quality analyzing unit904can also calculate, as the quality statistics specific to each moving speed range, the radio access bearer establishment failure rate, the radio access bearer release failure rate, or the like by the same method as that for the handover failure rate. The quality analyzing unit904can also handle the packet transfer throughput or packet transfer delay as the quality statistics specific to each moving speed range. The packet transfer throughput and packet transfer delay are measured by the mobile terminal30. Hence, to use the packet transfer throughput or packet transfer delay as the quality statistics, pieces of terminal information collected from a plurality of mobile terminals are classified by the moving speed range, and the average value of the packet transfer throughput or packet transfer delay is obtained for each moving speed range.

In the second exemplary embodiment of the present invention, the effects described in the first exemplary embodiment can be obtained in the above-described way.

The third exemplary embodiment to practice the present invention will be described next in detail with reference to the accompanying drawings. The third exemplary embodiment is different from the second exemplary embodiment in that quality statistics specific to each moving speed range are obtained for each communication type. [Description of Arrangement]

A mobile communication network according to the third exemplary embodiment is the same as that of the second exemplary embodiment, and a description thereof will be made using the reference numerals inFIGS. 3 to 5.

The operation of a quality monitoring apparatus90according to the third exemplary embodiment will be described with reference to the flowchart ofFIG. 10. Note that the operations in steps S101to S103and5105are the same as in the second exemplary embodiment, and a detailed description thereof will not be repeated.

When obtaining quality statistics specific to each moving speed range, a quality analyzing unit904of the quality monitoring apparatus90according to this exemplary embodiment refers to the communication type information included in the terminal information and obtains the moving speed range specific quality statistics for each communication type (step S111). For example, since the communication types are voice, packet, streaming, and the like, the quality analyzing unit904obtains the moving speed range specific quality statistics for each communication type.

As described above, according to the third exemplary embodiment of the present invention, since the moving speed range specific quality statistics are obtained for each communication type, it is possible to monitor quality in accordance with the communication type that requires a different service level.

Note that at least some of the components of the mobile terminals1and30and the quality monitoring apparatuses4and90according to the first to third exemplary embodiments can be implemented by a computer including a CPU, a storage device, and an interface to the outside. The CPU executes processing as described in the first to third exemplary embodiments in accordance with programs stored in the storage device.

The present invention has been described above with reference to the exemplary embodiments. However, the present invention is not limited to the above-described exemplary embodiments. The form and details of the present invention can be implemented by appropriately combining the above-described exemplary embodiments. In addition, changes and modifications can also be made without departing from the spirit and scope of the present invention as defined by the claims.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a quality monitoring system in a wireless communication network.