JP2012010305A - Adjacent cell processing device and adjacent cell processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adjacent cell processing device and an adjacent cell processing method capable of improving an efficiency of an operation in a radio communication system by generating proper adjacent cell information.SOLUTION: An adjacent cell processing device comprises a movement information acquisition part 11 for acquiring movement information which indicates a movement operation history of a radio terminal device 202 based on information from at least one of the radio terminal device 202 and a radio base station device 101, and an adjacent cell information generation part 12 for generating adjacent cell information which indicates one or more radio base station devices 101 located around a target radio base station device of the plural radio base station devices 101 other than the target radio base station device 101 based on the movement information acquired by the movement information acquisition part 11.

Description

  The present invention relates to an adjacent cell processing apparatus and an adjacent cell processing method, and more particularly to an adjacent cell processing apparatus and an adjacent cell processing method in a communication system capable of communicating with a plurality of radio base station apparatuses by a mobile terminal performing a moving operation. .

  Conventionally, in a mobile communication system, a communication service is provided by a radio base station apparatus (hereinafter also referred to as a macro base station) that forms an area in which a cell having a radius of several hundred meters to several tens of kilometers, that is, a radio terminal apparatus can communicate. It was.

  In recent years, due to a dramatic increase in the number of subscribers of mobile communication services and an increase in the amount of communication traffic due to data communication, subscribers and communication traffic are distributed by forming smaller radius cells, and a certain level of communication It is desirable to provide speed to users in a stable manner. In addition, in order to deal with dead zones associated with the increase in the number of buildings, it is desired to install radio base station devices on the corporate floor and in ordinary households.

  Together with these demands, the processing capability of various devices used in the radio base station apparatus has been dramatically improved, and the miniaturization of the radio base station apparatus has progressed. Collecting.

  Since the radius of the femto cell (Femto Cell) formed by this small base station (hereinafter also referred to as a femto base station) is as small as about 10 meters, the femto base station is the macro cell (Macro Cell) formed by the macro base station. It can be used in places such as homes and underground malls that are outside the service area and where it is difficult to install macro base stations.

  In addition, since many femto base stations are installed in a specific area, it is difficult to connect the femto base stations directly to the core network. For this reason, it is conceivable that a large number of femto base stations installed in a specific area are once connected to a gateway device such as a HeNB-GW, and the femto base station and the core network are connected via the HeNB-GW.

  In such a configuration, when an operator or a purchaser of a femto base station performs setting of each femto base station when installing the femto base station, considerable work and cost are required. Further, every time a femto base station is newly installed and the number of femto base stations is increased, not only newly installed femto base stations but also existing surrounding femto base stations must be reset.

  As a configuration for solving such problems, for example, Patent Document 1 discloses the following technique. That is, the new cell measures the signal strength of various different channels used by the existing cell. The new cell creates a list of candidate channels corresponding to channels with high signal strength and transmits this list to the mobile switching center of the cellular system. The mobile switching center determines which candidate channel corresponds to the beacon used in the existing cell and transmits configuration information about each of these existing cells to the new cell. Thus, the new cell automatically receives configuration information regarding neighboring cells. If the mobile switching center determines that the identified neighbor (adjacent cell) has not reached the maximum value N, then the mobile switching center will add additional candidate channels (ie, more (Candidate channel with low signal strength) is requested to be transmitted.

JP-A-11-333131

  The purchaser of the femto base station can uniquely determine the installation location of the femto base station. For this reason, in a radio communication system in which a femto base station is installed, the femto base station is likely to move and the power is turned on / off. Therefore, appropriate neighboring cell information in the radio base station apparatus in which the femto base station exists in the vicinity. It becomes difficult to generate.

  For example, the wireless terminal device measures the received power from the femto base station registered in the neighboring cell information autonomously or in accordance with an instruction from the femto base station using the neighboring cell information, and uses the measurement result. Report to femto base station. In this case, if a femto base station that is not suitable as a handover destination is registered in the neighboring cell information, the wireless terminal device performs a useless measurement operation, and a useless handover occurs.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an adjacent cell processing apparatus capable of increasing the efficiency of operation in a wireless communication system by generating appropriate adjacent cell information. And providing a neighbor cell processing method.

  (1) In order to solve the above-described problem, an adjacent cell processing apparatus according to an aspect of the present invention is an adjacent cell processing in a communication system in which a wireless terminal apparatus can communicate with a plurality of wireless base station apparatuses by performing a moving operation. A movement information acquisition unit for acquiring movement information indicating a movement operation history of the radio terminal apparatus based on information from at least one of the radio terminal apparatus and the radio base station apparatus, and the movement information Based on the movement information acquired by the acquisition unit, among a plurality of the radio base station devices other than the target radio base station device, one or a plurality of the radios arranged around the target radio base station device A neighboring cell information generating unit for generating neighboring cell information indicating a base station device, and the neighboring cell information generated by the neighboring cell information generating unit as the target And a neighboring cell information transmitting unit for transmitting the line base station or said target radio base station apparatus to communicable wireless terminal devices.

  With such a configuration, it is possible to automatically optimize neighboring cell information regardless of movement of the radio base station apparatus and power on / off, so that operation of the radio communication system can be performed without human intervention. Efficiency can be improved. In addition, since the neighboring cell information is automatically optimized, a special installation process for the radio base station apparatus is not required, so that the work time and cost for installing the radio base station apparatus can be reduced. Can do.

  Therefore, by generating appropriate neighboring cell information, it is possible to improve the efficiency of the operation in the radio communication system.

  (2) Preferably, the neighboring cell information generation unit ranks a plurality of the radio base station devices other than the target radio base station device based on the movement information acquired by the movement information acquisition unit. Next, neighboring cell information based on the ranking result is generated.

  With such a configuration, it is possible to generate detailed neighboring cell information and further improve the efficiency of the operation in the radio communication system. For example, the radio base station apparatus can increase the success rate of the movement operation by preferentially selecting a higher-level radio base station apparatus as a movement destination in the ranking result.

  (3) More preferably, the adjacent cell information generation unit indicates adjacent cells indicating N (N is an integer of 1 or more) of the radio base station devices from the top among the plurality of ranked radio base station devices. Generate information.

  With such a configuration, for example, when there is a limit to the number of radio base station apparatuses that can be included in the neighboring cell information notified to the radio terminal apparatus, the top N radio base station apparatuses can be included in the neighboring cell information. Thus, it is possible to notify the appropriate wireless cell apparatus of adjacent cell information.

  (4) More preferably, the neighboring cell information generation unit generates neighboring cell information further indicating the ranking of the ranked radio base station devices.

  With such a configuration, it is possible to generate more detailed neighboring cell information and further improve the efficiency of the operation in the radio communication system. For example, the radio terminal apparatus can perform an efficient measurement operation by determining the measurement order and narrowing down the radio base station apparatuses to be measured according to the rank of the radio base station apparatus in the neighboring cell information.

  (5) Preferably, the neighboring cell information generation unit includes a movement destination candidate of a radio terminal device communicating with the target radio base station device among the plurality of radio base station devices other than the target radio base station device. Neighboring cell information indicating one or a plurality of the radio base station apparatuses is generated.

  With this configuration, it is possible to optimize the movement operation within the cell of the installed radio base station apparatus. In addition, by optimizing neighboring cell information, the number of neighboring cells that are candidates for the destination of the wireless terminal device in communication can be reduced, so that it is possible to prevent unnecessary movement operations from occurring. .

  (6) Preferably, the neighboring cell information generation unit includes one or a plurality of the radio base stations to be measured by the radio terminal device among the plurality of radio base station devices other than the target radio base station device. Neighbor cell information indicating the device is generated.

  In this way, by optimizing the neighboring cell information, the number of neighboring cells to be measured by the wireless terminal device can be reduced, thereby preventing the wireless terminal device from performing a useless measurement operation. be able to.

  (7) Preferably, the neighboring cell information generation unit transmits a radio signal for which the radio terminal apparatus measures a reception level among the plurality of radio base station apparatuses other than the target radio base station apparatus. To generate neighboring cell information indicating one or a plurality of the radio base station apparatuses.

  In this way, by optimizing the neighboring cell information, the number of neighboring cells for which the wireless terminal device performs reception level measurement can be reduced, so that the wireless terminal device performs useless measurement operation. Can be prevented.

  (8) More preferably, the neighboring cell information generation unit receives the wireless terminal device that is not communicating with the target wireless base station device among the plurality of wireless base station devices other than the target wireless base station device. Neighbor cell information indicating one or a plurality of radio base station apparatuses that transmit a radio signal whose level is to be measured is generated.

  With such a configuration, the number of neighboring cells that are the targets of periodic power measurement indicated by broadcast information from the radio base station apparatus can be reduced, so that the radio terminal apparatus performs a useless measurement operation. Can be prevented. In particular, since the power consumption of the idle wireless terminal device can be reduced, a remarkable effect can be obtained.

  (9) More preferably, the adjacent cell information generation unit is configured to transmit a radio signal transmitted from the radio base station apparatus other than the target radio base station apparatus by a radio terminal apparatus communicating with the target radio base station apparatus. Based on the result of measuring the reception level at a plurality of frequencies, the initial information of the neighboring cell information is generated.

  With such a configuration, it is possible to construct appropriate neighboring cell information at an early stage, and it is possible to realize an efficient operation in the radio communication system at an early stage.

  (10) More preferably, in the adjacent cell processing device, the target wireless base station device can register the wireless terminal device, and the registered wireless terminal device and the unregistered wireless terminal device can be registered. When operating in a hybrid mode in which communication is permitted to both wireless terminal devices, the wireless base station device other than the target wireless base station device is transmitted to the wireless terminal device that is not registered. A power measurement instruction unit for instructing to measure the reception level of the wireless signal at the plurality of frequencies.

  With such a configuration, it is possible to prevent the power consumption of the wireless terminal device owned by the registered user from being consumed, so that an appropriate communication service can be provided.

  (11) More preferably, in the adjacent cell processing device, the target wireless base station device can further register the wireless terminal device, and the registered wireless terminal device and the unregistered wireless terminal device can be registered. When operating in a hybrid mode in which communication is permitted to both radio terminal apparatuses, the radio base station apparatus other than the target radio base station apparatus is transmitted to the registered radio terminal apparatus. A power measurement instruction unit is provided for instructing to measure the reception level of the radio signal at the plurality of frequencies.

  With such a configuration, it is possible to prevent the power consumption of the wireless terminal device owned by a non-registered user who often does not have an environment capable of immediately charging the wireless terminal device, so that an appropriate communication service is provided. Can be provided.

  (12) Preferably, the neighboring cell information generation unit allows the target radio base station apparatus to register the radio terminal apparatus, and the registered radio terminal apparatus and the unregistered radio terminal. When operating in a hybrid mode in which communication is permitted to both devices, the result of weighting and weighting the movement information of the registered wireless terminal device and the movement information of the unregistered wireless terminal device Based on the above, the neighboring cell information is generated.

  With this configuration, it is possible to generate appropriate neighboring cell information according to the registered wireless terminal device and the unregistered wireless terminal device.

  (13) Preferably, the movement information acquisition unit acquires movement information indicating a movement operation history of the wireless terminal device during a certain period from the present to the past.

  With such a configuration, for example, it is possible to prevent the rank of a radio base station apparatus that has been powered off from being kept high forever.

  (14) Preferably, at least one of the plurality of radio base station apparatuses in the communication system is a femto base station.

  As described above, by generating appropriate neighboring cell information in a wireless communication system in which movement of the wireless base station device and power on / off frequently occur, the effect of improving the operation efficiency in the wireless communication system is more remarkable. You can get to.

  (15) Preferably, the movement information acquisition unit moves indicating the number of movements of the radio terminal device between the target radio base station device and each of the plurality of radio base station devices other than the target radio base station device. Get information.

  Thus, appropriate neighboring cell information can be generated by including which radio base station device to include in the neighboring cell information and using the number of movements as a criterion for ranking the radio base station device.

  (16) More preferably, the movement information acquisition unit includes the number of movements of the radio terminal apparatus from the target radio base station apparatus to a plurality of radio base station apparatuses other than the target radio base station apparatus, and the target radio base Movement information indicating the number of movements of the wireless terminal device from the plurality of wireless base station devices other than the station device to the target wireless base station device is acquired.

  Thus, based on the number of bidirectional movements between the two radio base station devices, it is determined to delete the radio base station device from the neighboring cell information, and by ranking the radio base station devices, More optimal neighbor cell information can be generated.

  (17) More preferably, the neighboring cell information generation unit is configured to transmit the radio in which the number of movements indicated by the movement information is a predetermined value or less from a plurality of the radio base station apparatuses other than the target radio base station apparatus. The neighboring cell information excluding at least the base station apparatus is generated.

  With such a configuration, it is possible to appropriately delete a radio base station apparatus with a small track record actually selected as a destination from the neighboring cell information.

  (18) More preferably, the neighboring cell information generation unit ranks a plurality of the radio base station devices other than the target radio base station device based on the movement information acquired by the movement information acquisition unit. Then, in the ranking, the rank of the radio base station apparatus with the large number of movements indicated by the movement information is raised over the rank of the radio base station apparatus with the small number of movements.

  With such a configuration, it is possible to appropriately rank the radio base station apparatuses according to the actual results of successful mobile operation.

  (19) More preferably, the movement information acquisition unit is the latest certain number of radio terminals between the target radio base station apparatus and each of the plurality of radio base station apparatuses other than the target radio base station apparatus. The movement information indicating the movement operation history of the apparatus is acquired.

  With such a configuration, for example, it is possible to prevent the rank of a radio base station apparatus that has been powered off from being kept high forever.

  (20) Preferably, the movement information acquisition unit is a success rate of the movement operation of the radio terminal device between the target radio base station device and each of the plurality of radio base station devices other than the target radio base station device. The movement information indicating is acquired.

  Thus, appropriate neighboring cell information can be generated by using which mobile base station device to include in the neighboring cell information and using the mobile operation success rate as a criterion for ranking the wireless base station device. Here, the movement operation success rate is obtained by the number of movement completion notifications / the number of movement requests.

  (21) More preferably, the movement information acquisition unit is configured such that the success rate of the movement operation of the radio terminal apparatus from the target radio base station apparatus to the plurality of radio base station apparatuses other than the target radio base station apparatus, and the above Movement information indicating the success rate of the movement operation of the wireless terminal device from the plurality of wireless base station devices other than the target wireless base station device to the target wireless base station device is acquired.

  Thus, based on the success rate of the two-way moving operation between the two radio base station apparatuses, it is determined to delete the radio base station apparatus from the neighboring cell information, and the radio base station apparatuses are ranked. Thus, more optimal neighboring cell information can be generated.

  (22) More preferably, the neighboring cell information generation unit determines that the success rate of the moving operation indicated by the movement information is a predetermined value or less from a plurality of the radio base station apparatuses other than the target radio base station apparatus. The neighboring cell information excluding at least the radio base station apparatus is generated.

  With such a configuration, it is possible to appropriately delete a radio base station apparatus with a small track record of successful mobile operation from neighboring cell information.

  (23) More preferably, the neighboring cell information generation unit ranks a plurality of the radio base station devices other than the target radio base station device based on the movement information acquired by the movement information acquisition unit. Then, in the ranking, the rank of the radio base station apparatus having a high success rate of the moving operation indicated by the movement information is raised higher than that of the radio base station apparatus having a low success rate of the moving operation.

  With such a configuration, it is possible to appropriately rank the radio base station apparatuses according to the results of actual selection as a destination.

  (24) Preferably, the movement information acquisition unit is configured to apply the target for the first radio base station device and the second radio base station device among the plurality of radio base station devices other than the target radio base station device. When the wireless terminal device moves between the wireless base station device and the second wireless base station device via the first wireless base station device, the wireless terminal device moves to the first wireless base station device. The movement information indicating the staying time until moving to the target radio base station apparatus or the second radio base station apparatus is acquired.

  As described above, which radio base station device is included in the neighboring cell information, and a radio terminal in the radio base station device through which the radio terminal device passes during the moving operation, as a criterion for ranking the radio base station device in the neighboring cell information By using the stay time of the device, it is possible to generate appropriate neighboring cell information.

  (25) More preferably, the neighboring cell information generation unit is configured to make the stay time indicated by the movement information equal to or less than a predetermined value from among the plurality of radio base station apparatuses other than the target radio base station apparatus. The neighboring cell information excluding at least one radio base station apparatus is generated.

  With such a configuration, it is possible to appropriately delete, from the neighboring cell information, a radio base station apparatus that the radio terminal apparatus does not need to go through in the moving operation.

  (26) More preferably, the neighboring cell information generation unit ranks a plurality of the radio base station devices other than the target radio base station device based on the movement information acquired by the movement information acquisition unit. Then, in the ranking, the rank of the radio base station apparatus having the long stay time indicated by the movement information is raised as compared with the radio base station apparatus having the short stay time.

  With such a configuration, it is possible to appropriately rank the radio base station apparatuses according to the necessity of passing through the radio terminal apparatus in the moving operation.

  (27) More preferably, the movement information acquisition unit includes a first radio base station apparatus and a plurality of remaining second radio base stations among the plurality of radio base station apparatuses other than the target radio base station apparatus. When the wireless terminal device moves between the target wireless base station device and each of the plurality of second wireless base station devices via the first wireless base station device, the wireless terminal device Movement information indicating each stay time from moving to the first radio base station apparatus to moving to the target radio base station apparatus and the plurality of second radio base station apparatuses is acquired.

  With such a configuration, when a part of the radio base station apparatuses in the radio communication system is set as the movement destination or the movement source, the first radio base station apparatus required as a path of the movement operation is erroneously determined from the neighboring cell information. It is possible to prevent deletion and accidental lowering in neighboring cell information.

  (28) More preferably, the neighboring cell information generation unit performs the movement information for all of the plurality of second radio base station devices from among the plurality of radio base station devices other than the target radio base station device. The neighboring cell information excluding at least the first radio base station apparatus in which the stay time indicated by is equal to or less than a predetermined value is generated.

  With such a configuration, when a part of the radio base station apparatuses in the radio communication system is set as the movement destination or the movement source, the first radio base station apparatus required as a path of the movement operation is erroneously determined from the neighboring cell information. It can be prevented from being deleted.

  (29) More preferably, the movement information acquisition unit further acquires movement information indicating whether or not a radio terminal apparatus communicating with the target radio base station apparatus can communicate with the second radio base station apparatus. .

  Thus, in addition to the information of the movement operation history, more optimal neighboring cell information can be generated by a configuration in which information of other contents is acquired as movement information.

  (30) More preferably, the neighboring cell information generation unit is configured such that the stay time indicated by the movement information is a predetermined value or less from a plurality of the radio base station devices other than the target radio base station device, and the The adjacent cell information excluding at least the first radio base station device when the radio terminal device communicating with the target radio base station device can communicate with the second radio base station device is generated.

  With such a configuration, it is possible to prevent a cell that is not actually adjacent from being recognized as if it is adjacent, and an out-of-service state from occurring.

  (31) Preferably, the adjacent cell processing device is included in one or a plurality of the radio base station devices.

  With such a configuration, for example, there is no need to optimize neighboring cell information of each radio base station device in the gateway device or the host device, and the processing load in the radio communication system is distributed, and the radio base station device and the gateway device or the host device. The amount of communication with the apparatus can be reduced.

  (32) In order to solve the above-mentioned problem, an adjacent cell processing method according to an aspect of the present invention is an adjacent cell processing in a communication system in which a wireless terminal device can communicate with a plurality of wireless base station devices by performing a moving operation. A method of acquiring movement information indicating a movement operation history of the wireless terminal device based on information from at least one of the wireless terminal device and the wireless base station device, and based on the acquired movement information And generating neighboring cell information indicating one or a plurality of the radio base station devices arranged around the target radio base station device among the plurality of radio base station devices other than the target radio base station device. And a step of transmitting the generated neighboring cell information to the target radio base station apparatus or a radio terminal apparatus capable of communicating with the target radio base station apparatus. Including the door.

  With such a configuration, it is possible to automatically optimize neighboring cell information regardless of movement of the radio base station apparatus and power on / off, so that operation of the radio communication system can be performed without human intervention. Efficiency can be improved. In addition, since the neighboring cell information is automatically optimized, a special installation process for the radio base station apparatus is not required, so that the work time and cost for installing the radio base station apparatus can be reduced. Can do.

  Therefore, by generating appropriate neighboring cell information, it is possible to improve the efficiency of the operation in the radio communication system.

  According to the present invention, it is possible to improve the efficiency of operation in a wireless communication system by generating appropriate neighboring cell information.

It is a figure which shows the structure of the radio | wireless communications system which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the femto base station which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the signal processing part which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the installation place of a femto base station, and femtocell arrangement | positioning. It is a figure which shows the other example of the method of producing | generating initial adjacent cell information. It is a figure which shows an example of the sequence from the communication start between the radio | wireless terminal apparatus and femto base station to the completion of a handover in the radio | wireless communications system which concerns on the 1st Embodiment of this invention. FIG. 7 is a diagram illustrating an example of a sequence in which a femto base station acquires handover information in the wireless communication system according to the first embodiment of the present invention. FIG. 5 is a diagram illustrating an example of a route along which a wireless terminal device moves at the installation location illustrated in FIG. 4. It is a figure which shows an example of the sequence which the femto base station which concerns on the 1st Embodiment of this invention acquires handover information, and the acquired handover information. In the radio | wireless communications system which concerns on the 1st Embodiment of this invention, a femto base station is a figure which shows an example of the method of notifying adjacent cell information to a radio | wireless terminal apparatus. In the radio | wireless communications system which concerns on the 1st Embodiment of this invention, a femto base station is a figure which shows an example of the method of notifying adjacent cell information to a radio | wireless terminal apparatus. In the radio | wireless communications system which concerns on the 1st Embodiment of this invention, a femto base station is a figure which shows an example of the method of notifying adjacent cell information to a radio | wireless terminal apparatus. It is a figure which shows the structure of the gateway apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the data processing part in the gateway apparatus which concerns on the 2nd Embodiment of this invention. FIG. 11 is a diagram illustrating an example of a handover operation in the radio communication system according to the second embodiment of the present invention and an operation in which the gateway device acquires handover information. It is a figure which shows an example of the sequence which the gateway apparatus which concerns on the 2nd Embodiment of this invention acquires handover information, and the acquired handover information. It is a figure which shows an example of the operation | movement in a radio | wireless communications system which concerns on the 3rd Embodiment of this invention, and the operation | movement in which a gateway apparatus acquires handover information. It is a figure which shows an example of the hand-over information which the gateway apparatus concerning the 3rd Embodiment of this invention acquired. It is a figure which shows an example of the cell arrangement | positioning in the radio | wireless communications system which concerns on the 3rd Embodiment of this invention. It is a figure which shows generation | occurrence | production of the unintended out-of-service state in the cell arrangement | positioning shown in FIG. It is a flowchart which shows the operation | movement procedure at the time of the gateway apparatus which concerns on the 3rd Embodiment of this invention optimizing neighboring cell information. It is a figure which shows the relationship between the radio | wireless terminal apparatus which can be connected with the access mode of the femto base station which concerns on the 4th Embodiment of this invention. It is a figure which shows the example of arrangement | positioning of the radio base station apparatus in the radio | wireless communications system which concerns on the 4th Embodiment of this invention. It is a figure which shows the structure of the signal processing part in the radio base station apparatus which concerns on the 4th Embodiment of this invention. In the radio | wireless communications system which concerns on the 4th Embodiment of this invention, a radio base station apparatus is a figure which shows an example of the sequence which produces | generates adjacent cell information. In the radio | wireless communications system which concerns on the 4th Embodiment of this invention, it is a figure which shows an example of the sequence with which a radio base station apparatus acquires handover information. It is a figure which shows the operation | movement which the radio base station apparatus which concerns on the 4th Embodiment of this invention updates neighboring cell information. It is a figure which shows the other example of the operation | movement which the radio base station apparatus which concerns on the 4th Embodiment of this invention updates neighboring cell information. It is a figure which shows an example of the hand-over information which the gateway apparatus concerning the 5th Embodiment of this invention acquired. It is a figure which shows an example of the adjacent cell information which the gateway apparatus which concerns on the 5th Embodiment of this invention produces | generates.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<First Embodiment>
[Configuration and basic operation]
FIG. 1 is a diagram showing a configuration of a wireless communication system according to the first embodiment of the present invention.

  Referring to FIG. 1, a wireless communication system 301 is a mobile communication system that complies with, for example, LTE (Long Term Evolution) standardized by 3GPP (Third Generation Partnership Project), and includes a macro base station 201, a femto base station ( Wireless base station apparatus) 101A, 101B, 101C, 101D, gateway apparatus 203, and host apparatus 205.

  Hereinafter, each of the femto base stations 101A, 101B, 101C, and 101D may be referred to as a femto base station 101. Further, in FIG. 1, one macro base station and four femto base stations are representatively shown, but a small number or even more macro base stations and femto base stations may be provided.

  In the radio communication system according to the first embodiment of the present invention, the femto base stations 101A, 101B, 101C, and 101D each operate as an adjacent cell processing apparatus. That is, each of the femto base stations 101A, 101B, 101C, and 101D optimizes adjacent cell information by itself.

  The macro base station 201 forms a macro cell MC having a radius of several kilometers, for example. In addition, the femto base stations 101A, 101B, 101C, and 101D form femtocells FCA, FCB, FCC, and FCD having a radius of several tens of meters, for example.

  The macro base station 201 can communicate with the wireless terminal device 202 by transmitting and receiving wireless signals to and from the wireless terminal device 202 existing in the macro cell MC.

  The femto base stations 101A, 101B, 101C, and 101D are installed in places where the wireless terminal device 202 is difficult to receive wireless signals from the macro base station 201, such as in homes and underground malls, and in femtocells FCA, FCB, FCC, and FCD, respectively. The wireless terminal device 202 can communicate with the wireless terminal device 202 by transmitting and receiving wireless signals to and from the wireless terminal device 202 existing in the network.

  The gateway device 203 performs relay processing of various communication data transmitted between the femto base stations 101A, 101B, 101C, and 101D and the host device 205 in the core network 204.

FIG. 2 is a diagram illustrating the configuration of the femto base station according to the first embodiment of the present invention.
Referring to FIG. 2, femto base station 101 includes antenna 91, circulator 92, wireless reception unit 93, wireless transmission unit 94, and signal processing unit 95. The signal processing unit 95 includes a reception signal processing unit 96 and a transmission signal processing unit 97. The signal processing unit 95 is realized by a CPU (Central Processing Unit) or a DSP (Digital Signal Processor).

  The circulator 92 outputs the radio signal from the radio terminal device 202 received by the antenna 91 to the radio reception unit 93 and outputs the radio signal received from the radio transmission unit 94 to the antenna 91.

  The radio reception unit 93 converts the radio signal received from the circulator 92 into a baseband signal or IF (Intermediate Frequency) signal, converts the frequency-converted signal into a digital signal, and outputs the digital signal to the reception signal processing unit 96.

  The received signal processing unit 96 performs signal processing such as despreading in the CDMA (Code Division Multiple Access) method on the digital signal received from the wireless receiving unit 93, and part or all of the digital signal after this signal processing is performed. The data is converted into a predetermined frame format and transmitted to the gateway device 203.

  The transmission signal processing unit 97 performs IFFT (Inverse Fast Fourier Transform) in an OFDM (Orthogonal Frequency Division Multiplex) method on communication data obtained by converting communication data received from the gateway device 203 into a predetermined frame format or communication data generated by itself. The digital signal after the signal processing is output to the wireless transmission unit 94.

  The radio transmission unit 94 converts the digital signal received from the transmission signal processing unit 97 into an analog signal, converts the frequency of the converted analog signal into a radio signal, and outputs the radio signal to the circulator 92.

FIG. 3 is a diagram illustrating a configuration of the signal processing unit according to the first embodiment of the present invention.
With reference to FIG. 3, received signal processing section 96 includes a handover information acquisition section 11 and a neighboring cell information generation section 12. The transmission signal processing unit 97 includes an adjacent cell information transmission unit 13.

  The handover information acquisition unit 11 acquires handover information indicating a handover operation history of the wireless terminal device 202 based on information from at least one of the other femto base station 101 and the wireless terminal device 202.

  Based on the handover information acquired by the handover information acquisition unit 11, the adjacent cell information generation unit 12 is a wireless communication system other than a femto base station (hereinafter also referred to as a target femto base station) to which adjacent cell information is provided. Among the plurality of femto base stations 101 in 301, neighboring cell information indicating one or more femto base stations 101 installed around the target femto base station is generated.

  For example, the neighboring cell information generation unit 12 generates neighboring cell information indicating one or more femto base stations 101 that are candidates for a handover destination of the wireless terminal device 202 that communicates with the target femto base station. In the femto base station according to the first embodiment of the present invention, the target femto base station is its own femto base station 101.

  The neighboring cell information transmission unit 13 is a wireless terminal device 202 that can communicate the neighboring cell information generated by the neighboring cell information generation unit 12 with its own femto base station 101, that is, a femto cell formed by its own femto base station 101. To the wireless terminal device 202 existing in

[Generate initial neighbor cell information]
FIG. 4 is a diagram illustrating an example of an installation location of femto base stations and an arrangement of femto cells.
Referring to FIG. 4, femto base stations 101A, 101B, 101C, and 101D are installed in, for example, an underground mall, and are formed so that a part of each of femtocells FCA, FCB, FCC, and FCD overlap each other. The underground shopping area is partitioned by a plurality of structures WA, so that a plurality of passages PA are formed.

  For example, when each femto base station 101 is installed and activated, the femto base station 101 searches for its own surrounding femto base station 101 and generates initial neighboring cell information indicating the searched femto base station. In FIG. 4, the femto base station 101C generates initial neighboring cell information indicating the searched femto base stations 101A, 101B, and 101D. In the wireless communication system 301, the generation method and collection method of the non-optimized neighboring cell information in the initial stage are arbitrary.

FIG. 5 is a diagram illustrating another example of a method for generating initial neighboring cell information.
Referring to FIG. 5, femto base stations 101A, 101B, 101C, and 101D may acquire neighboring cell information from gateway apparatus 203 to which each femto base station 101 is connected in common. For example, the gateway device 203 notifies each femto base station 101 of adjacent cell information obtained by removing the target femto base station from the connected subordinate femto base stations 101A, 101B, 101C, and 101D.

[Collect handover information]
FIG. 6 is a diagram illustrating an example of a sequence from the start of communication to the completion of handover between the wireless terminal device and the femto base station in the wireless communication system according to the first embodiment of the present invention.

  Referring to FIG. 6, first, various control processes at the previous stage for transmitting / receiving communication data such as link setting of a radio control signal, that is, IP (Internet Protocol) packet, are performed between radio terminal apparatus 202 and femto base station 101A. (Step S1).

  Next, NAS (Non-Access Stratum) layer security processing, that is, transmission / reception of information necessary for communication encryption is performed between the wireless terminal device 202 and the femto base station 101A (step S2). For example, in LTE, the wireless terminal device 202 exchanges the information with the host device 205 in the core network 204, and the femto base station 101A plays a role of relaying the information.

  Next, a wireless data link is set between the wireless terminal device 202 and the femto base station 101A. For example, in the femto base station 101A, resource allocation processing for transmitting and receiving communication data such as IP packets is performed, and thereafter, communication data is transmitted and received between the wireless terminal device 202 and the femto base station 101A. Further, the femto base station 101A transmits a measurement start request for causing the wireless terminal device 202 to measure the reception level of the wireless signal transmitted from the other femto base station 101 (step S3). For example, in LTE, the measurement start request is included in the wireless data link setting request notified from the femto base station 101A to the wireless terminal device 202.

  Next, the wireless terminal device 202 receives the measurement start request from the femto base station 101A, and measures the reception level of the wireless signal transmitted from the femto base station 101 indicated by the neighboring cell information held by itself (Step). S4).

  Next, the wireless terminal device 202 transmits a measurement result notification indicating the measurement result of the reception level to the femto base station 101A (step S5).

  Next, based on the measurement result notification received from the wireless terminal device 202, the femto base station 101A determines whether or not the wireless terminal device 202 should be handed over. The station 101B is determined as a handover destination (step S6).

  Here, in the radio communication system according to the embodiment of the present invention, handover means that the femto base station 101 that is a communication partner of the radio terminal apparatus 202 during a call or data communication is switched.

  Next, the femto base station 101A transmits a handover request to the femto base station 101B (step S7).

  Next, the femto base station 101B receives the handover request from the femto base station 101A, and transmits a handover response to the handover request to the femto base station 101A (step S8).

  Next, when the handover response received from the femto base station 101B indicates that the handover is possible, the femto base station 101A transmits a handover instruction to the wireless terminal device 202 (step S9).

  Next, the link setting of the radio control signal is performed between the radio terminal device 202 and the femto base station 101B (step S10). At this time, the wireless control signal link and the wireless data link are canceled between the wireless terminal device 202 and the femto base station 101A.

  Next, NAS layer security processing is performed between the wireless terminal device 202 and the femto base station 101B (step S11).

  Next, a wireless data link is set between the wireless terminal device 202 and the femto base station 101B, and thereafter, communication data such as IP packets is transmitted and received between the wireless terminal device 202 and the femto base station 101B (step S12). .

  Next, the femto base station 101B transmits a handover completion notification to the femto base station 101A (step S13).

  Next, the femto base station 101A receives handover completion notification from the femto base station 101B, thereby acquiring handover information, that is, updating the number of handovers held by itself (step S14). Then, the femto base station 101A optimizes neighboring cell information as necessary.

  Next, the femto base station 101A releases the resources allocated to the wireless terminal device 202 when the call or data communication by the wireless terminal device 202 is completed (step S15).

  FIG. 7 is a diagram illustrating an example of a sequence in which the femto base station acquires handover information in the wireless communication system according to the first embodiment of the present invention.

  Referring to FIG. 7, first, handover occurs in wireless terminal apparatus 202A with femto base station 101A as the handover destination or handover source (step S21).

  Next, the femto base station 101A reflects and updates the contents of the handover operation that has occurred in the wireless terminal device 202A in the handover information (step S22).

  Next, handover is performed in the wireless terminal device 202B with the femto base station 101A as the handover destination or handover source (step S23).

  Next, the femto base station 101A reflects and updates the contents of the handover operation that has occurred in the wireless terminal device 202B in the handover information (step S24).

  Next, handover occurs with the femto base station 101A as the handover destination or handover source in the wireless terminal device 202C (step S25).

  Next, the femto base station 101A reflects and updates the contents of the handover operation that has occurred in the wireless terminal device 202C in the handover information (step S26).

  Next, the femto base station 101A optimizes neighboring cell information based on the updated handover information (step S27).

  FIG. 8 is a diagram illustrating an example of a route along which the wireless terminal device moves at the installation location illustrated in FIG.

  Referring to FIG. 8, when wireless terminal apparatus 202 that exists in femtocell FCB and is communicating with femto base station 101B moves as indicated by each arrow in FIG. 8, wireless terminal apparatus 202 moves to femto base station 101B. To femto base station 101A, femto base station 101C, and femto base station 101D.

  That is, when the wireless terminal device 202 that exists in the femtocell FCB and is communicating with the femto base station 101B moves as indicated by the arrows in FIG. 8, the communication partner of the wireless terminal device 202 moves from the femto base station 101B to the femto cell. Switching to base station 101A, femto base station 101C, and femto base station 101D, respectively.

  FIG. 9 is a diagram illustrating an example of a sequence in which the femto base station according to the first embodiment of the present invention acquires handover information and the acquired handover information.

  Referring to FIG. 9, femto base station 101B acquires handover information according to the sequences shown in FIGS. That is, the femto base station 101B counts and holds the number of handovers for each femto base station that is the handover destination each time a handover occurs in each wireless terminal device 202 and the handover is completed (steps S51 and S53). The existing handover count table is updated (steps S52 and S54).

  Specifically, first, in the femto base station 101B, the handover from the femto base station 101B to the femto base station 101A occurs 19 times, and the handover from the femto base station 101B to the femto base station 101C occurs once. A handover number table indicating that 15 handovers from the base station 101B to the femto base station 101D have been obtained.

  Next, when a handover from the femto base station 101B to the femto base station 101A occurs in the wireless terminal device 202, the femto base station 101A transmits a handover completion notification to the femto base station 101B (step S51).

  Next, the femto base station 101B receives the handover completion notification from the femto base station 101A, and changes the number of handovers from the femto base station 101B to the femto base station 101A in the handover number table from 19 times to 20 times (step) S52).

  Next, when a handover from the femto base station 101B to the femto base station 101C occurs in the wireless terminal device 202, the femto base station 101C transmits a handover completion notification to the femto base station 101B (step S53).

  Next, the femto base station 101B receives the handover completion notification from the femto base station 101C, and changes the number of handovers from the femto base station 101B to the femto base station 101C from one to two in the handover number table (step) S54).

  The femto base station 101B optimizes neighboring cell information every time a handover completion notification is received or every predetermined period. For example, the handover information acquisition unit 11 in the femto base station 101B sets the number of times that the wireless terminal device 202 performs handover from the femto base station 101B to the femto base station 101A, the femto base station 101C, and the femto base station 101D, for example, from 6 hours to 1 Handover information is obtained by counting for a period of about days.

  In the example shown in FIG. 9, during a predetermined measurement period, handover from the femto base station 101B to the femto base station 101A occurs 20 times, and handover from the femto base station 101B to the femto base station 101C occurs twice. A handover number table indicating that 15 handovers from the base station 101B to the femto base station 101D have been obtained.

  As described above, the handover information acquisition unit 11 in the femto base station 101B is a wireless terminal device 202 between the target femto base station, that is, the femto base station 101B and each of the femto base stations 101A, 101C, and 101D other than the femto base station 101B. Handover information indicating the number of handovers, for example, the number of times the femto base stations 101A, 101C, and 101D become handover destinations is acquired.

[Optimization of neighboring cell information]
The neighboring cell information generation unit 12 in the femto base station 101B obtains neighboring cell information excluding at least the femto base station 101 in which the number of handovers indicated by the handover information is a predetermined value or less from the femto base stations 101A, 101C, and 101D. Generate.

  Specifically, the number of wireless terminal devices 202 that are handed over from the femto base station 101B to the femto base station 101C based on the above-mentioned handover frequency table is the number of wireless terminal devices 202 that are handed over from the femto base station 101B to the femto base stations 101A and 101D, respectively. It can be seen that it is extremely small compared to the number of. Therefore, the neighboring cell information generation unit 12 estimates that the femtocell FCC is a cell that does not exist on the actual path of the wireless terminal device 202 moving from the femtocell FCB, and sets the femto base station 101B as the target femto base. It is determined that the femto base station 101C may be deleted from the neighboring cell information as a station.

  As a specific determination method at this time, for example, the following can be considered. That is, the neighboring cell information generation unit 12 sets the femto base station 101 that is the handover destination whose number of handovers is 1 / N or less of 20 times that of the femto base station 101A with the largest number of handovers (N is a natural number of 2 or more). Delete from neighboring cell information. Alternatively, the neighboring cell information generation unit 12 may calculate the average average number of handovers, that is, 1 / N or less of the average value of the number of handovers to the femto base station 101A, the femto base station 101C, and the femto base station 101D (N is a natural number of 2 or more ) Is deleted from the neighboring cell information.

  Note that the handover information acquisition unit 11 may be configured to acquire handover information indicating a handover operation history of the wireless terminal device 202 during a certain period in the past from the present. That is, the neighboring cell information generation unit 12 may be configured to generate neighboring cell information based on a handover operation history in a certain period from the present to the past. For example, the neighboring cell information generation unit 12 may generate neighboring cell information based on a handover operation history in a period from the current time to one day ago. Also, the neighboring cell information generation unit 12 may generate neighboring cell information based on a history for a predetermined number of handovers. For example, the neighboring cell information generation unit 12 may generate neighboring cell information based on the latest 30 previous trials of handover attempts. With such a configuration, for example, it is possible to prevent the femto base station 101 whose power has been turned off from remaining in the neighboring cell information indefinitely.

[Notification of neighboring cell information]
As described above, the femto base station 101 optimizes neighboring cell information at a certain timing as the handover information is updated. The optimized neighboring cell information needs to be notified to the wireless terminal device 202. That is, the neighboring cell information transmission unit 13 in the femto base station 101 transmits the neighboring cell information generated by the neighboring cell information generation unit 12 to the wireless terminal device 202 that can communicate with the own femto base station 101 that is the target femto base station. Send. As the notification method, for example, the following three methods are conceivable.

  FIG. 10 is a diagram illustrating an example of a method in which the femto base station notifies the wireless terminal device of neighboring cell information in the wireless communication system according to the first embodiment of the present invention.

  Referring to FIG. 10, femto base station 101 </ b> A notifies wireless terminal apparatus 202 in an idle state, i.e., a state in which communication and data communication are not being performed, with neighboring cell information included in broadcast information. In this case, the femto base station 101A notifies the wireless terminal device 202 that the neighboring cell information has been updated using the notification information change notification.

  More specifically, when optimization of neighboring cell information occurs (step S27), the femto base station 101A broadcasts a broadcast information change notification to each wireless terminal device 202 existing in the femtocell FCA (step S28).

  Next, the femto base station 101A broadcasts broadcast information including updated neighbor cell information to each wireless terminal device 202 existing in the femtocell FCA. And the radio | wireless terminal apparatus 202 which received notification information change notification reads neighboring cell information from the alerting | reporting information transmitted from femto base station 101A, and updates the neighbor cell information which self hold | maintains to the read neighboring cell information. (Step S29).

  Next, the wireless terminal device 202 receives a measurement start request autonomously or from the femto base station 101A, and measures the reception level of the wireless signal transmitted from the femto base station 101 indicated by the updated neighboring cell information ( Step S30).

  FIG. 11 is a diagram illustrating an example of a method in which the femto base station notifies the wireless terminal device of neighboring cell information in the wireless communication system according to the first embodiment of the present invention.

  Referring to FIG. 11, for example, in LTE, radio terminal apparatus 202 that performs processing for establishing an RRC (Radio Resource Control) connection, that is, radio terminal apparatus 202 that performs processing for starting communication with femto base station 101A, The femto base station 101A notifies neighboring cell information when setting a wireless data link.

  More specifically, first, a radio control signal link is set between the radio terminal apparatus 202 and the femto base station 101A (step S31).

  Next, NAS layer security processing is performed between the wireless terminal device 202 and the femto base station 101A (step S32).

  Next, a wireless data link is set between the wireless terminal device 202 and the femto base station 101A, and thereafter communication data such as IP packets is transmitted and received between the wireless terminal device 202 and the femto base station 101A. Further, the femto base station 101A transmits to the wireless terminal device 202 a measurement start request for causing the wireless terminal device 202 to measure the reception level of the wireless signal transmitted from another femto base station (step S33). For example, in LTE, the measurement start request is included in the wireless data link setting request notified from the femto base station 101A to the wireless terminal device 202. The measurement start request includes neighboring cell information.

  Next, the wireless terminal device 202 receives the measurement start request from the femto base station 101A, updates the neighbor cell information held by itself to the newly notified neighbor cell information, and updates the updated neighbor cell information. The reception level of the radio signal transmitted from the indicated femto base station 101 is measured (step S34).

  FIG. 12 is a diagram illustrating an example of a method in which the femto base station notifies the wireless terminal device of neighboring cell information in the wireless communication system according to the first embodiment of the present invention.

  Referring to FIG. 12, femto base station 101 </ b> A notifies wireless terminal apparatus 202 in communication with itself of the update of neighboring cell information using a measurement change request.

  More specifically, when optimization of neighboring cell information occurs (step S27), the femto base station 101A includes the updated neighboring cell information in the measurement change request and transmits it to the wireless terminal device 202 (step S41).

  Next, the wireless terminal device 202 changes the neighboring cell information held by itself to the neighboring cell information included in the measurement change request received from the femto base station 101A, and the femto base station 101 indicated by the changed neighboring cell information. The reception level of the radio signal transmitted from is measured (step S42).

  By the way, the purchaser of the femto base station can uniquely determine the installation location of the femto base station. For this reason, in a radio communication system in which a femto base station is installed, the femto base station is likely to move and the power is turned on / off. Therefore, appropriate neighboring cell information in the radio base station apparatus in which the femto base station exists in the vicinity. It becomes difficult to generate.

  For example, the wireless terminal device measures the received power from the femto base station registered in the neighboring cell information autonomously or in accordance with an instruction from the femto base station using the neighboring cell information, and uses the measurement result. Report to femto base station. In this case, if a femto base station that is not suitable as a handover destination is registered in the neighboring cell information, the wireless terminal device performs a useless measurement operation, and a useless handover occurs.

  On the other hand, in the wireless communication system according to the first embodiment of the present invention, the handover information acquisition unit 11 uses the handover information indicating the handover operation history of the wireless terminal device 202 as information from the wireless terminal device 202, that is, Obtained based on the handover completion notification. Based on the handover information acquired by the handover information acquisition unit 11, the neighboring cell information generation unit 12 is 1 or 2 installed around the target femto base station among the plurality of femto base stations 101 other than the target femto base station. Neighbor cell information indicating a plurality of femto base stations 101 is generated.

  With such a configuration, the neighboring cell information can be automatically optimized regardless of the movement of the femto base station and the power on / off. Therefore, the operation of the wireless communication system 301 can be performed without human intervention. Efficiency can be improved. In addition, since the neighboring cell information is automatically optimized, a special installation process for the femto base station 101 is not necessary, so that the work time and cost for installing the femto base station 101 can be reduced. Can do.

  Further, when the femto base station is automatically set using the technique described in Patent Document 1, all of the neighboring femto base stations are treated as neighboring cells and registered in neighboring cell information, which is a candidate for a handover destination. For this reason, there is a possibility that a femto base station that is not originally suitable for a handover destination may be registered in the neighboring cell information, such as a femto base station existing on the other side of the wall with respect to the wireless terminal device.

  On the other hand, in the radio communication system according to the first embodiment of the present invention, the neighboring cell information generation unit 12 is based on the handover information acquired by the handover information acquisition unit 11 and other than the target femto base station. Among the plurality of femto base stations 101, neighboring cell information indicating one or more femto base stations 101 that are candidates for a handover destination of the wireless terminal device 202 communicating with the target femto base station is generated.

  With such a configuration, it is possible to optimize the handover operation in the femtocell of the installed femto base station 101. Further, by optimizing the neighboring cell information, the number of neighboring cells that are handover destination candidates for the wireless terminal device 202 in communication can be reduced, so that it is possible to prevent unnecessary handover from occurring. .

  Moreover, in the radio | wireless communications system which concerns on the 1st Embodiment of this invention, the adjacent cell information generation part 12 becomes a measuring object of the radio | wireless terminal apparatus 202 among several femto base stations 101 other than object femto base station. Neighboring cell information indicating one or more femto base stations 101 is generated.

  Thus, by optimizing the neighboring cell information, the number of neighboring cells to be measured by the wireless terminal device 202 can be reduced, so that the wireless terminal device 202 performs a useless measurement operation. Can be prevented.

  Moreover, in the radio | wireless communications system which concerns on the 1st Embodiment of this invention, the adjacent cell information production | generation part 12 measures the reception level by the radio | wireless terminal apparatus 202 among the some femto base stations 101 other than the object femto base station. Next, neighboring cell information indicating one or more femto base stations 101 that transmit a radio signal to be transmitted is generated.

  As described above, by optimizing the neighboring cell information, the number of neighboring cells for which the wireless terminal device 202 performs reception level measurement can be reduced, so that the wireless terminal device 202 performs a useless measurement operation. Can be prevented.

  Moreover, in the radio | wireless communications system which concerns on the 1st Embodiment of this invention, the adjacent cell information production | generation part 12 communicates with an idle state, ie, object femto base station, among several femto base stations 101 other than object femto base station. The wireless terminal device 202 that is not in the middle generates neighboring cell information indicating one or more femto base stations 101 that transmit a wireless signal whose reception level is to be measured.

  With such a configuration, it is possible to reduce the number of neighboring cells that are the targets of periodic power measurement instructed by broadcast information from the femto base station 101 and the like, so that the wireless terminal device 202 performs a wasteful measurement operation. Can be prevented. In particular, since the power consumption of the wireless terminal device 202 in the idle state can be reduced, a remarkable effect can be obtained.

  In the radio communication system according to the first embodiment of the present invention, the handover information acquisition unit 11 is a radio terminal between the target femto base station and each of the plurality of femto base stations 101 other than the target femto base station. Handover information indicating the number of handovers of the device 202 is acquired.

  Thus, appropriate neighboring cell information can be generated by using the number of handovers as a criterion for determining which femto base station is included in the neighboring cell information.

  Moreover, in the radio | wireless communications system which concerns on the 1st Embodiment of this invention, the adjacent cell information production | generation part 12 is a target femto base station and a target femto base from several femto base stations 101 other than the target femto base station. Neighbor cell information excluding at least the femto base station 101 in which the number of handovers of the wireless terminal device 202 between each of the plurality of femto base stations 101 other than the station is a predetermined value or less is generated.

  With such a configuration, it is possible to appropriately delete the femto base station 101 with a small track record actually selected as the handover destination from the neighboring cell information.

  Further, in the wireless communication system according to the first embodiment of the present invention, femto base station 101 alone optimizes neighboring cell information. That is, the neighboring cell processing apparatus according to the first embodiment of the present invention is included in the femto base station 101. With such a configuration, for example, it is not necessary to optimize the neighboring cell information of each femto base station 101 by the gateway device 203 or the higher-level device 205, the processing load in the wireless communication system 301 is distributed, and the femto base station 101 and the gateway The amount of communication with the device 203 or the host device 205 can be reduced.

  In the wireless communication system according to the first embodiment of the present invention, the femto base station 101 performs the handover from each other femto base station 101 to the other femto base station 101, that is, the number of times the other femto base station 101 is a handover destination. The number of times is acquired as the handover information, and the neighboring cell information is generated based on this information. However, the present invention is not limited to this. The femto base station 101 uses, as handover information, the number of times each other femto base station 101 becomes a handover source, that is, the number of handovers from each other femto base station 101 to itself, and the wireless terminal that has handed over this handover information to itself, for example The configuration may be such that neighboring cell information is generated based on information from the device 202.

  Further, in the wireless communication system according to the first embodiment of the present invention, the femto base station 101 that is the communication partner of the wireless terminal device 202 is configured to be switched by the femto base station 101 as a handover operation. However, the present invention is not limited to this. The configuration may be such that the femto base station 101 that is the communication partner of the wireless terminal device 202 is switched by the wireless terminal device 202.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Second Embodiment>
This embodiment relates to a wireless communication system in which a gateway device operates as an adjacent cell processing device instead of a femto base station as compared with the wireless communication system according to the first embodiment. The contents other than those described below are the same as those of the wireless communication system according to the first embodiment.

FIG. 13 is a diagram illustrating a configuration of a gateway device according to the second embodiment of the present invention.
Referring to FIG. 13, gateway device 203 includes base station side transmission / reception unit 81, data processing unit 82, and core network side transmission / reception unit 83.

  The base station side transmitting / receiving unit 81 transmits the communication data received from the data processing unit 82 to each femto base station 101, and outputs the communication data received from each femto base station 101 to the data processing unit 82.

  The data processing unit 82 performs various processes on the communication data received from the base station side transmission / reception unit 81, outputs the processed data to the core network side transmission / reception unit 83, and performs various processing on the communication data received from the core network side transmission / reception unit 83. Processing is performed and output to the base station side transceiver 81.

  The core network side transmission / reception unit 83 outputs the communication data received from the data processing unit 82 to the higher order device 205 in the core network 204, and outputs the communication data received from the higher order device 205 in the core network 204 to the data processing unit 82. To do.

  In the radio communication system according to the second embodiment of the present invention, the gateway device 203 monitors the entire femto base station under its control and optimizes neighboring cell information. For example, the gateway device 203 collects statistical information on the number of handovers between the femto base stations 101.

  FIG. 14 is a diagram showing a configuration of a data processing unit in the gateway device according to the second embodiment of the present invention.

  Referring to FIG. 14, data processing unit 82 includes a handover information acquisition unit 21, an adjacent cell information generation unit 22, and an adjacent cell information transmission unit 23.

  The handover information acquisition unit 21 acquires handover information indicating a handover operation history of the wireless terminal device 202 based on information from each femto base station 101.

  Based on the handover information acquired by the handover information acquisition unit 21, the neighboring cell information generation unit 22 is located around the target femto base station among the plurality of femto base stations 101 in the wireless communication system 301 other than the target femto base station. Neighbor cell information indicating one or more installed femto base stations 101 is generated.

  For example, the neighboring cell information generation unit 22 generates neighboring cell information indicating one or more femto base stations 101 that are candidates for a handover destination of the wireless terminal device 202 that communicates with the target femto base station.

  The neighboring cell information transmission unit 23 transmits the neighboring cell information generated by the neighboring cell information generation unit 22 to the target femto base station.

  FIG. 15 is a diagram illustrating an example of a handover operation in the wireless communication system according to the second embodiment of the present invention and an operation in which the gateway device acquires handover information.

  Referring to FIG. 15, gateway device 203 connects to each femto base station 101 having a certain femto base station 101 as a handover source based on information from each of femto base stations 101A, 101B, 101C, and 101D. A handover number table indicating the number of handovers or the number of handovers from other femto base stations 101 whose handover destination is a certain femto base station 101 is acquired as handover information.

  FIG. 16 is a diagram illustrating an example of a sequence in which the gateway device according to the second embodiment of the present invention acquires handover information and the acquired handover information.

  Referring to FIG. 16, when a handover occurs, gateway device 203 collects information indicating the handover operation from each femto base station 101.

  At this time, the information notified from the femto base station 101 is information that allows confirmation from which femto base station 101 to which femto base station 101 the handover has been performed. That is, this information includes identification information of the handover source femto base station and identification information of the handover destination femto base station. It is arbitrary whether the femto base station 101 at the handover source or the handover destination notifies the gateway device 203 of the information.

  Further, the gateway device 203 updates the handover number table based on the collected information, and updates the neighboring cell information based on the updated handover number table, and notifies each femto base station 101 of the updated neighboring cell information. The gateway device 203 separately generates neighboring cell information required by each femto base station 101 and notifies each femto base station 101 of the information. The femto base station 101 notifies the wireless terminal device 202 of the neighboring cell information received from the gateway device 203 by the same method as the femto base station according to the first embodiment of the present invention.

  More specifically, first, in the gateway device 203, handover occurs 19 times between the femto base station 101A and the femto base station 101B, and 12 handovers occur between the femto base station 101A and the femto base station 101C. A handover frequency table is obtained that indicates that handover has occurred 0 times between the station 101A and the femto base station 101D, and that 5 handovers have occurred between the femto base station 101B and the femto base station 101C.

  Next, when a handover from the femto base station 101B to the femto base station 101A occurs in the wireless terminal device 202, the femto base station 101A transmits information indicating the handover operation to the gateway device 203 (step S61).

  Next, the gateway device 203 changes the number of handovers between the femto base station 101A and the femto base station 101B in the handover number table from 19 times to 20 times based on the information received from the femto base station 101A (step S62). .

  Next, when a handover from the femto base station 101B to the femto base station 101C occurs in the wireless terminal device 202, the femto base station 101B transmits information indicating the handover operation to the gateway device 203 (step S63).

  Next, the gateway device 203 changes the number of handovers between the femto base station 101B and the femto base station 101C in the handover number table from 5 to 6 based on the information received from the femto base station 101B (step S64). .

  Next, when a handover from the femto base station 101C to the femto base station 101B occurs in the wireless terminal device 202, the femto base station 101C transmits information indicating the handover operation to the gateway device 203 (step S65).

  Next, the gateway device 203 changes the number of handovers between the femto base station 101B and the femto base station 101C in the handover number table from 6 times to 7 times based on the information received from the femto base station 101C (step S66). .

  In the example shown in FIG. 16, during a predetermined measurement period, 20 handovers occur between the femto base station 101A and the femto base station 101B, and 12 handovers occur between the femto base station 101A and the femto base station 101C. A handover number table is obtained that indicates that the handover has occurred 0 times between the base station 101A and the femto base station 101D and the handover has occurred 7 times between the femto base station 101B and the femto base station 101C.

  In this case, for example, the gateway device 203 deletes the femto base station 101D with a small number of handovers from the neighboring cell information in which the femto base station 101A is the target femto base station.

  Here, in the wireless communication system according to the first embodiment of the present invention, for example, a femto base is located in a place where there are many mobile users in one direction in the morning of the day and many mobile users in the opposite direction in the afternoon of the day. When a station is installed and the measurement period by the femto base station is in the morning, the femto base station may be erroneously deleted from neighboring cell information because the number of handovers is small.

  On the other hand, in the radio communication system according to the second embodiment of the present invention, the handover information acquisition unit 21 transmits a radio terminal device from the target femto base station to a plurality of femto base stations 101 other than the target femto base station. Handover information indicating the number of handovers 202 and the number of handovers of the wireless terminal device 202 from a plurality of femto base stations other than the target femto base station to the target femto base station is acquired. That is, since the configuration is such that the deletion of the femto base station 101 from the neighboring cell information is determined based on the number of bidirectional handovers between the two femto base stations 101, more optimal neighboring cell information can be generated. .

  Although the gateway device according to the second embodiment of the present invention is configured to be provided separately from the femto base station 101, the present invention is not limited to this. The gateway device 203 may be configured to be included in at least one of the femto base stations 101 in the wireless communication system 301. In this case, the femto base station 101 on which the gateway device 203 is mounted acquires handover information based on information from the wireless terminal device 202 and the other femto base stations 101 existing in the femto cell formed by itself. Then, the gateway device 203 notifies the generated neighboring cell information to the wireless terminal device 202 and other femto base stations 101 existing in the femto cell formed by itself.

  Since other configurations and operations are the same as those of the wireless communication system according to the first embodiment, detailed description thereof will not be repeated here.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Third Embodiment>
The present embodiment relates to a radio communication system in which the content of handover information is changed as compared with the radio communication system according to the second embodiment. The contents other than those described below are the same as those of the wireless communication system according to the second embodiment.

  FIG. 17 is a diagram illustrating an example of a handover operation in the radio communication system according to the third embodiment of the present invention and an operation in which the gateway device acquires handover information.

  With reference to FIG. 17, when the wireless terminal device 202 that exists in the femtocell FCA and is communicating with the femto base station 101A moves as indicated by the arrow R1 in FIG. 17, the wireless terminal device 202 moves to the femto base station 101A. From the femto base station 101C to the femto base station 101D. When the wireless terminal device 202 that exists in the femtocell FCB and is communicating with the femto base station 101B moves as indicated by an arrow R2 in FIG. 17, the wireless terminal device 202 moves from the femto base station 101B to the femto base station 101C. And then hand over from the femto base station 101C to the femto base station 101A. When the wireless terminal device 202 that exists in the femtocell FCB and is communicating with the femto base station 101B moves as indicated by an arrow R3 in FIG. 17, the wireless terminal device 202 moves from the femto base station 101B to the femto base station 101C. And then hand over from the femto base station 101C to the femto base station 101D.

  FIG. 18 is a diagram illustrating an example of handover information acquired by the gateway device according to the third embodiment of the present invention.

  Referring to FIG. 18, gateway device 203 acquires the following handover information. That is, when the radio terminal device 202 is handed over between the femto base station 101A and the femto base station 101D via the femto base station 101C, the femto base station 101A or the femto base station 101A or The time until handover to the femto base station 101D, that is, the average staying time in the femtocell FCC is 20 seconds.

  Also, when the wireless terminal device 202 is handed over between the femto base station 101A and the femto base station 101B via the femto base station 101C, the femto base station 101A or the femto base station 101A or The time until handover to the femto base station 101B, that is, the average staying time in the femtocell FCC is 5 seconds.

  Further, when the radio terminal device 202 is handed over between the femto base station 101B and the femto base station 101D via the femto base station 101C, the femto base station 101B or the femto base station 101B or The time until handover to the femto base station 101D, that is, the average staying time in the femtocell FCC is 2 seconds.

  Using these pieces of information, gateway device 203 determines whether or not femto base station 101C should be deleted from the neighboring cell information of femto base stations 101A, 101B, and 101D. That is, for neighboring cell information with the femto base station 101A as the target femto base station, the stay time at the femto base station 101C in the handover between the femto base station 101A and the femto base station 101B is as short as 5 seconds. Since the stay time at the femto base station 101C in the handover between the base station 101A and the femto base station 101D is as long as 20 seconds, the femto base station 101C is not deleted.

  Further, the gateway device 203 sets the femto base station 101D as the target femto base station, and the remaining time in the femto base station 101C in the handover between the femto base station 101D and the femto base station 101B is 2 seconds. However, since the stay time at the femto base station 101C in the handover between the femto base station 101D and the femto base station 101A is as long as 20 seconds, the femto base station 101C is not deleted.

  On the other hand, for the neighboring cell information in which the femto base station 101B is the target femto base station, the gateway device 203 has a residence time of 5 seconds in the femto base station 101C in the handover between the femto base station 101B and the femto base station 101A. Since the stay time at the femto base station 101C in the handover between the femto base station 101B and the femto base station 101D is as short as 2 seconds, the femto base station 101C is deleted.

  As described above, in the wireless communication system according to the third embodiment of the present invention, the handover information acquisition unit 21 in the gateway device 203 uses the first femto base station among the plurality of femto base stations 101 other than the target femto base station. For the base station and the remaining plurality of second femto base stations, the wireless terminal device 202 performs handover between the target femto base station and each of the remaining plurality of second femto base stations via the first femto base station. Handover information indicating each stay time from when the wireless terminal device 202 is handed over to the first femto base station to when handing over to the target femto base station and the remaining plurality of second femto base stations. To do. For example, the handover information acquisition unit 21 acquires this handover information based on information from the first femto base station.

  In FIG. 17 and FIG. 18, the case where the target femto base station is the femto base station 101A, 101B, 101D and the first femto base station is the femto base station 101C is shown as an example.

  Thus, as a criterion for determining which femto base station to include in the neighboring cell information, by using the stay time of the wireless terminal device 202 in the femto base station through which the wireless terminal device 202 has passed at the time of handover, appropriate neighboring cell information Can be generated.

  Then, the neighboring cell information generation unit 22 sets the stay time indicated by the handover information for all of the second femto base stations out of the plurality of femto base stations other than the target femto base station to a predetermined value or less, as shown in FIG. Then, for example, neighboring cell information excluding at least the first femto base station that is 5 seconds or less is generated.

  With such a configuration, the femto base station 101 that the wireless terminal device 202 does not need to pass through in the handover operation can be appropriately deleted from the neighboring cell information.

  FIG. 19 is a diagram illustrating an example of cell arrangement in the wireless communication system according to the third embodiment of the present invention. FIG. 20 is a diagram showing the occurrence of an unintended out-of-service state in the cell arrangement shown in FIG.

  Referring to FIG. 19, when the wireless terminal device 202 moves from the femtocell FCB to the femtocell FCA via the femtocell FCC as indicated by an arrow, the wireless terminal device 202 moves from the femto base station 101B to the femto base station. Handover to 101A is performed via the femto base station 101C. In this case, since the distance between the femtocell FCA and the femtocell FCB is short, the staying time from when the wireless terminal apparatus 202 is handed over to the femto base station 101C until the handover to the femto base station 101A is shortened. Therefore, as described in FIGS. 17 and 18, the gateway device 203 deletes the femto base station 101 </ b> C from the neighboring cell information in which the femto base station 101 </ b> B is the target femto base station.

  However, in the cell arrangement shown in FIG. 19, since the femtocell FCB and the femtocell FCA are not actually adjacent to each other, as shown in FIG. 20, the wireless terminal device 202 moves from the femtocell FCB to the femto along the path indicated by the arrow. When moving to the cell FCA, the wireless terminal device 202 cannot directly perform handover from the femto base station 101B to the femto base station 101A, and the wireless terminal device 202 enters an out-of-service state.

  Therefore, the gateway device 203 according to the third embodiment of the present invention is present in the femtocell FCB, and whether or not the wireless terminal device 202 communicating with the femto base station 101B can communicate with the femto base station 101A. For example, whether or not the level of the radio signal received from the femto base station 101A is equal to or higher than a predetermined value is acquired as handover information.

  That is, the handover information acquisition unit 21 uses the handover information indicating whether or not the wireless terminal device 202 communicating with the target femto base station can communicate with the second femto base station as received power information from the wireless terminal device 202 or the like. Get based on.

  Thus, in addition to the information of the handover operation history, more optimal neighboring cell information can be generated by a configuration in which information of other contents is acquired as the handover information.

  FIG. 21 is a flowchart showing an operation procedure when the gateway device according to the third embodiment of the present invention optimizes neighboring cell information.

  Referring to FIG. 21, adjacent cell information generation unit 22 has a stay time indicated by the handover information for a second femto base station out of a plurality of femto base stations 101 other than the target femto base station equal to or less than a predetermined value. And the first femto base station 101 in the case where the wireless terminal device 202 communicating with the target femto base station can communicate with all the second femto base stations (YES in step S72). At least excluded neighbor cell information is generated (step S73).

  With such a configuration, it is possible to prevent a femto cell that is not actually adjacent to be recognized as if it is adjacent, and an out-of-service state from occurring.

  In the gateway device according to the third embodiment of the present invention, for example, when the femto base station 101B is the target femto base station, handover is performed for both of the second femto base stations, that is, the femto base stations 101A and 101D. Although the configuration is such that neighboring cell information is generated excluding at least the first femto base station, that is, the femto base station 101C, whose stay time indicated by the information is equal to or less than a predetermined value, the present invention is not limited to this.

  The handover information acquisition unit 21 acquires the stay time for some of the second femto base stations as handover information among all the second femto base stations, and the neighboring cell information generation unit 22 stores the handover information in the handover information. Based on this, it may be configured to determine whether to remove the first femto base station from the neighboring cell information.

  With such a configuration, it is possible to adjust the deletion condition of the first femto base station from the neighboring cell information according to the installation environment of each femto base station.

  However, as in the gateway apparatus according to the third embodiment of the present invention, handover information regarding all second femto base stations is acquired, and the neighboring cell information generation unit 22 performs the first based on the handover information. The first femto base station required as a handover path when a part of the femto base stations is set as a handover destination or a handover source is determined by determining whether or not to remove the femto base station from the adjacent cell information. Accidental deletion from neighboring cell information can be prevented.

  Similarly, the handover information acquisition unit 21 obtains handover information indicating whether or not the wireless terminal device 202 communicating with the target femto base station can communicate with the second femto base station for each second femto base station. The neighboring cell information generation unit 22 may determine whether to remove the first femto base station from the neighboring cell information based on the handover information.

  Also, the optimization of neighboring cell information according to the first embodiment or the second embodiment of the present invention and the optimization of neighboring cell information according to the third embodiment of the present invention may be combined. Good. That is, as a criterion for determining which femto base station to include in the neighboring cell information, the number of handovers of the wireless terminal device 202 and the stay time of the wireless terminal device 202 in the femto base station through which the wireless terminal device 202 has passed at the time of handover are combined It is also possible. Further, as a criterion for determining which femto base station to include in the neighboring cell information, information on whether or not the wireless terminal device 202 can communicate with the femto base station 101 serving as a handover destination candidate can be added to this combination. It is.

  Moreover, although the gateway apparatus according to the third embodiment of the present invention is configured to be provided separately from the femto base station 101, the present invention is not limited to this. The gateway device 203 may be configured to be included in at least one of the femto base stations 101 in the wireless communication system 301. In this case, the femto base station 101 on which the gateway device 203 is mounted acquires handover information based on information from the wireless terminal device 202 and the other femto base stations 101 existing in the femto cell formed by itself. Then, the gateway device 203 notifies the generated neighboring cell information to the wireless terminal device 202 and other femto base stations 101 existing in the femto cell formed by itself.

  Also, the macro base station can perform the same operation as that of the femto base station according to the first to third embodiments of the present invention.

  Since other configurations and operations are the same as those of the wireless communication system according to the second embodiment, detailed description thereof will not be repeated here.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Fourth embodiment>
The present embodiment relates to a radio communication system that ranks adjacent cell information as compared with the radio communication system according to the first embodiment. The contents other than those described below are the same as those of the wireless communication system according to the first embodiment.

  The radio base station apparatus notifies the radio terminal apparatus of information about the cell and the neighboring cell that it forms, that is, the frequency of the radio signal and the ID (identification) of the neighboring cell. The wireless terminal device detects and measures neighboring cells based on information notified from the wireless base station device. The wireless terminal device starts moving to the neighboring cell based on the measurement result. Here, “movement” of the wireless terminal device means not only handover but also through which cell the wireless terminal device in an idle state starts communication in the future, that is, when a call or data communication is started. This means selecting whether to perform communication.

  For example, when the wireless terminal device is communicating with the wireless base station device, the wireless base station device or the host device determines the destination of the wireless terminal device. Further, when the wireless terminal device is not communicating with the wireless base station device, the wireless terminal device determines the destination of the wireless terminal device.

  FIG. 22 is a diagram illustrating a relationship between the access mode of the femto base station according to the fourth embodiment of the present invention and a connectable wireless terminal apparatus.

  Referring to FIG. 22, the femto base station according to the fourth embodiment of the present invention has three access modes. That is, in the closed access mode, only registered wireless terminal apparatuses can be connected to the femto base station. In the open access mode, the wireless terminal devices that can be connected to the femto base station are all wireless terminal devices, which are the same as those of a normal macro base station. In the hybrid mode, all the wireless terminal devices that can be connected to the femto base station are all wireless terminal devices. However, in the hybrid mode, a member, that is, a registered wireless terminal device, may be favored in terms of allocation of a communication resource of the femto base station, charging, and the like, compared to a non-member, that is, a wireless terminal device that is not registered.

  That is, the femto base station according to the fourth embodiment of the present invention can operate in an open access mode in which communication is permitted to all wireless terminal devices 202 or can register the wireless terminal devices 202. Yes, it is possible to operate in a closed access mode that allows communication to the registered wireless terminal device 202, or the wireless terminal device 202 can be registered, and the registered wireless terminal device 202 and not registered It is possible to set whether to operate in a hybrid mode in which communication is permitted to both of the wireless terminal devices 202.

  In the cell in the closed access mode, 3GPP stipulates that the wireless terminal device 202 autonomously detects neighboring cells. In addition, in a macro cell in the open access mode, when a business operator systematically installs a radio base station device, the business operator also knows information related to surrounding macro cells, and during installation and maintenance of the radio base station device. It is set at the time.

  By the way, since the user can install the femto base station at an arbitrary place, it is difficult for the femto base station to grasp the current location. For this reason, it is difficult for the femto base station to obtain information on neighboring cells.

  As described above, the femto cell detection method and the movement method of the wireless terminal device in the cell in the closed access mode are defined by 3GPP. However, when the wireless terminal device moves from the macro cell or the femto cell to the macro cell or the femto cell in the open access mode, the wireless base station device of the movement source notifies the wireless terminal device of the information of the wireless base station device of the movement destination. There is a need to.

  Here, since the use location of the femto base station is uniquely determined by the user, the femto base station may move and the power may be turned on / off. As a result, the following two problems become problems. That is, since the femto base station cannot grasp the current location, it is difficult to acquire information on cells arranged in the vicinity by the OAM function (maintenance function). In addition, when a femto base station exists in the vicinity of the radio base station apparatus and the femto base station is powered off, the radio terminal apparatus cannot move to the femto base station. It becomes necessary to detect the on / off state of the power source.

  If the femto base station can identify the current location using GPS (Global Positioning System) or the like, it is possible that the femto base station makes an inquiry to the carrier network to acquire information on cells that are geographically close. However, it is difficult to specify an accurate position due to the problem of accuracy.

[Configuration and basic operation]
FIG. 23 is a diagram illustrating an arrangement example of the radio base station devices in the radio communication system according to the fourth embodiment of the present invention.

  Referring to FIG. 23, in radio communication system 301, radio base station apparatuses 501A, 501C, and 501D are femto base stations, and radio base station apparatus 501B is a macro base station. Consider a state in which a plurality of femto base stations exist in the macro cell MCB formed by the radio base station apparatus 501B.

  A part of each of femtocells FCA and FCC formed by radio base station apparatus 501A and radio base station apparatus 501C overlap each other. Further, a part of each of femtocells FCA and FCD formed by radio base station apparatus 501A and radio base station apparatus 501D overlap each other.

  In the radio communication system according to the fourth embodiment of the present invention, radio base station apparatuses 501A, 501B, 501C, and 501D each operate as an adjacent cell processing apparatus.

  Hereinafter, each of the radio base station apparatuses 501A, 501B, 501C, and 501D may be referred to as a radio base station apparatus 501.

  FIG. 24 is a diagram illustrating a configuration of a signal processing unit in the radio base station apparatus according to the fourth embodiment of the present invention.

  Referring to FIG. 24, signal processing unit 105 includes a reception signal processing unit 106 and a transmission signal processing unit 107. The received signal processing unit 106 includes a handover information acquisition unit 31 and an adjacent cell information generation unit 32. The transmission signal processing unit 107 includes an adjacent cell information transmission unit 33 and a power measurement instruction unit 34.

  The neighboring cell information generation unit 32 is a radio communication system other than a radio base station apparatus (hereinafter also referred to as a target base station) to which neighboring cell information is provided based on the handover information acquired by the handover information acquisition unit 31. Among the plurality of radio base station apparatuses 501 in 301, neighboring cell information indicating one or a plurality of radio base station apparatuses 501 installed around the target base station is generated. In the radio base station apparatus according to the fourth embodiment of the present invention, the target base station is its own radio base station apparatus 501.

  The neighboring cell information transmitting unit 33 is formed by the wireless terminal device 202 that can communicate the neighboring cell information generated by the neighboring cell information generating unit 32 with its own radio base station device 501, that is, its own radio base station device 501. It transmits to the radio | wireless terminal apparatus 202 which exists in a cell.

  The power measurement instruction unit 34 transmits to the wireless terminal device 202 a measurement start request for causing the wireless terminal device 202 to measure the reception level of the wireless signal transmitted from the other wireless base station device 501.

[Operation]
Next, an operation when the radio base station apparatus according to the fourth embodiment of the present invention generates neighboring cell information will be described.

  FIG. 25 is a diagram illustrating an example of a sequence in which the wireless base station device generates neighboring cell information, in the wireless communication system according to the fourth embodiment of the present invention.

  With reference to FIG. 25, when the radio base station apparatus 501 does not have neighboring cell information, such as when the radio base station apparatus 501 is activated, the radio terminal apparatus 202 first establishes RRC with the radio base station apparatus 501. When the connection is established, the radio base station apparatus 501 instructs the radio terminal apparatus 202 to search for all frequencies. Here, the all frequency search means that the reception level of the radio signal from each radio base station apparatus 501 is measured for all types of transmission frequencies set in the radio communication system.

  Then, the radio base station apparatus 501 generates neighboring cell information based on the measurement result report from the radio terminal apparatus 202 and stores it in a storage unit (not shown).

  More specifically, first, the radio base station device 501A sets another radio base station device to be measured by the radio terminal device 202 (step S101).

  Next, the radio base station apparatus 501A transmits to the radio terminal apparatus 202 a measurement start request for causing the radio terminal apparatus 202 to measure the reception level of the radio signal transmitted from the other set radio base station apparatus. This measurement start request includes information on the radio base station apparatus to be measured (step S102).

  Next, radio terminal apparatus 202 receives the measurement start request from radio base station apparatus 501A, and measures the reception level of the radio signal transmitted from the radio base station apparatus indicated by the received measurement start request (step S103). .

  Next, the wireless terminal device 202 transmits a measurement result notification indicating the reception level measurement result to the wireless base station device 501A (step S104).

  Next, the radio base station apparatus 501A generates initial neighboring cell information based on the measurement result notification received from the radio terminal apparatus 202 (step S105).

  Note that the radio base station apparatus 501A may instruct the radio terminal apparatus 202 that first establishes the RRC connection not only at the time of activation but to search for all frequencies for every fixed period.

  In addition, when the radio base station apparatus 501A is a femto base station and operates in the hybrid mode, the radio base station apparatus 501A, when the non-member radio terminal apparatus 202 establishes an RRC connection, for example, The terminal device 202 is instructed to search all frequencies.

  That is, when the target base station operates in the hybrid mode, the power measurement instruction unit 34 transmits a radio signal transmitted from the radio base station apparatus 501 other than the target base station to the radio terminal apparatus 202 that is not registered. It is instructed to measure the reception level at all frequencies.

  With such a configuration, it is possible to prevent the power consumption of the wireless terminal device 202 owned by the registered user from being consumed, so that an appropriate communication service can be provided.

  Alternatively, when the target base station operates in the hybrid mode, the power measurement instruction unit 34 transmits a radio signal transmitted from the radio base station apparatus 501 other than the target base station to the registered radio terminal apparatus 202. The configuration may be such that the reception level is measured at all frequencies.

  With such a configuration, it is possible to prevent the power consumption of the wireless terminal device 202 owned by a non-registered user who often does not have an environment capable of charging the wireless terminal device 202 immediately. Communication services can be provided.

  Next, a method for updating neighboring cell information generated by the sequence shown in FIG. 25 will be described.

  The radio base station apparatus 501 ranks the list of radio base station apparatuses indicated by initial neighboring cell information stored in a storage unit (not shown) using an index. That is, the adjacent cell information generation unit 32 generates adjacent cell information in which a plurality of radio base station apparatuses 501 other than the target base station are ranked based on the handover information acquired by the handover information acquisition unit 31.

  For example, in the handover operation of the wireless terminal device 202, when the wireless base station device 501 transmits a handover request to the higher-level device 205, a handover destination wireless base station device included in the request is stored in a storage unit (not shown). Save to.

  Also, the radio base station apparatus 501 recognizes the success of the handover by the handover completion notification from the higher-level apparatus 205, and stores this information in a storage unit (not shown). As a result, the number of handovers or the handover success rate can be set as one of the indexes for ranking.

  Here, the handover success rate is obtained by the number of handover completion notifications / the number of handover requests.

  FIG. 26 is a diagram illustrating an example of a sequence in which the wireless base station device acquires handover information in the wireless communication system according to the fourth embodiment of the present invention.

  Referring to FIG. 26, first, radio base station apparatus 501A sets another radio base station apparatus 501 to be measured by radio terminal apparatus 202 (step S81).

  Next, the radio base station apparatus 501A transmits to the radio terminal apparatus 202 a measurement start request for causing the radio terminal apparatus 202 to measure the reception level of the radio signal transmitted from the other set radio base station apparatus 501. This measurement start request includes information on the radio base station apparatus 501 to be measured. For example, the neighboring cell information generated by the sequence shown in FIG. 25 is included, and the transmission frequency of each radio base station apparatus 501 is included (step S82).

  Next, radio terminal apparatus 202 receives the measurement start request from radio base station apparatus 501A, and measures the reception level of the radio signal transmitted from radio base station apparatus 501 indicated by the received measurement start request (step S83). ).

  Next, the wireless terminal device 202 transmits a measurement result notification indicating the measurement result of the reception level to the wireless base station device 501A. For example, the wireless terminal device 202 periodically measures the reception level, and when the communication state with the wireless base station device 501A deteriorates, and with other wireless base station devices 501 other than the wireless base station device 501A When the communication state is improved, a measurement result notification is transmitted to the radio base station apparatus 501A (step S84).

  Next, based on the measurement result notification received from the radio terminal apparatus 202, the radio base station apparatus 501A determines whether or not the radio terminal apparatus 202 should be handed over. For example, radio base station apparatus 501B is determined as a handover destination with reference to the information, and a handover request indicating radio base station apparatus 501B is transmitted to host apparatus 205 (step S85).

  Then, the radio base station apparatus 501A acquires handover destination information, that is, recognizes a handover attempt of the radio terminal apparatus 202 to the radio base station apparatus 501B, and updates the handover information based on this information (step S86). .

  Next, the host device 205 receives the handover request from the radio base station device 501A, and transmits the handover request to the radio base station device 501B (step S87).

  Next, the radio base station device 501B receives the handover request from the higher-level device 205, and transmits a handover response to the handover request to the higher-level device 205 (step S88).

  Next, the host device 205 receives a handover response from the radio base station device 501B, and transmits a handover instruction to the radio base station device 501A (step S89).

  Next, the radio base station apparatus 501A receives the handover instruction from the higher-level apparatus 205 and transmits an RRC connection re-establishment instruction to the radio terminal apparatus 202 (step S90).

  Next, the radio base station device 501A transmits a status notification indicating its own communication status and the like to the higher-level device 205 (step S91).

  Next, the host device 205 receives the status notification from the radio base station device 501A, and transmits a status notification indicating the communication contents and the like with the radio terminal device 202 to the radio base station device 501B (step S92).

  When the RRC connection is established between the wireless terminal device 202 and the wireless base station device 501B, the wireless terminal device 202 transmits an RRC connection establishment notification to the wireless base station device 501B (step S93).

  Next, the radio base station apparatus 501B receives the RRC connection establishment notification from the radio terminal apparatus 202, and transmits a handover completion notice to the higher-level apparatus 205 (step S94).

  Next, the host apparatus 205 receives the handover completion notification from the radio base station apparatus 501B and transmits a terminal information release instruction to the radio base station apparatus 501A (step S95).

  Next, the radio base station device 501A receives a terminal information release instruction from the higher-level device 205, releases information related to the wireless terminal device 202, and transmits a terminal information release completion notification to the higher-level device 205 (step S96).

  Then, the radio base station apparatus 501A acquires handover result information, that is, recognizes the success of the handover of the radio terminal apparatus 202 to the radio base station apparatus 501B, and updates the handover information based on this information (step S97). .

  Next, an operation in which the radio base station apparatus according to the fourth embodiment of the present invention updates neighboring cell information will be described.

  Referring to FIG. 23 again, in the wireless communication system 301, when the wireless terminal device 202 communicating with the wireless base station device 501A moves away from the wireless base station device 501A, the wireless base station device 501B, 501C and 501D are conceivable.

  Here, a specific example of an update method in the case where there are three measurement target radio base station apparatuses, that is, three movement destination candidates, which are notified to the radio terminal apparatus 202 by the radio base station apparatus 501A will be described.

  FIG. 27 is a diagram illustrating an operation in which the radio base station device according to the fourth embodiment of the present invention updates neighboring cell information.

  Referring to FIG. 27, first, in radio base station apparatus 501A, handover is attempted 12 times in a certain period. That is, in the radio base station apparatus 501A, the handover from the radio base station apparatus 501A to the radio base station apparatus 501B is attempted five times and succeeded five times, and the handover from the radio base station apparatus 501A to the radio base station apparatus 501C is six. The handover information indicating that the handover from the radio base station apparatus 501A to the radio base station apparatus 501D has been attempted once and succeeded 0 times, that is, the handover history table is obtained.

  In this handover history table, the success rate of handover from the radio base station device 501A to the radio base station device 501B is 1.00, and the success rate of handover from the radio base station device 501A to the radio base station device 501C is It is 0.33, and it is also shown that the success rate of handover from the radio base station apparatus 501A to the radio base station apparatus 501D is zero.

  Further, in the radio base station apparatus 501A, adjacent cell information is obtained in which the radio base station apparatus 501B is ranked first, the radio base station apparatus 501C is ranked second, and the radio base station apparatus 501D is ranked third ( FIG. 27 (1)).

  In this state, it is assumed that handover of the wireless terminal device 202 existing in the femtocell FCA formed by the wireless base station device 501A to the wireless base station device 501D is attempted.

  When radio base station apparatus 501A transmits a handover request to radio base station apparatus 501D, the number of handover attempts to radio base station apparatus 501D in the handover history table of radio base station apparatus 501A is updated to 2 (FIG. 27). (2)).

  Then, when receiving the handover completion notification from the radio base station apparatus 501D, the radio base station apparatus 501A changes the number of successful handovers to the radio base station apparatus 501D to 1 in the handover history table, calculates the handover success rate to 0 Change to .50.

  Accordingly, when the handover success rate is used as an index for ranking, the radio base station device 501D is higher than the radio base station device 501C in the neighboring cell information. That is, the radio base station apparatus 501A is updated to neighboring cell information in which the radio base station apparatus 501B is first, the radio base station apparatus 501D is second, and the radio base station apparatus 501C is third (FIG. 27). (3)).

  On the other hand, when the handover success number is used as an index for ranking, there is no change in the rank of the radio base station apparatus in the neighboring cell information.

  Then, when the adjacent cell information is updated, for example, the wireless base station device 501A notifies the updated wireless cell device 202 of the updated adjacent cell information. Here, the radio base station apparatus 501A, for example, notifies the radio terminal apparatus 202 of N cells (N is an integer of 1 or more) from the top among the ranked radio base station apparatuses as neighboring cell information.

  Specifically, when the number of wireless base station devices that can be registered in the neighboring cell information notified to the wireless terminal device 202 is limited to two, and the handover success rate is used as an index for ranking, the wireless base station device 501A notifies each radio terminal device 202 of neighboring cell information indicating that the radio base station device 501B is first and the radio base station device 501D is second. In addition, when the number of successful wireless base station devices that can be registered in the neighboring cell information notified to the wireless terminal device 202 is limited to two and the number of successful handovers is used as an index for ranking, the wireless base station device 501A It notifies each wireless terminal device 202 of neighboring cell information indicating that the wireless base station device 501B is ranked first and the wireless base station device 501C is ranked second.

  FIG. 28 is a diagram illustrating another example of operation in which the radio base station device according to the fourth embodiment of the present invention updates neighboring cell information.

  Referring to FIG. 28, first, in radio base station apparatus 501A, a handover history table and neighboring cell information having the same contents as in (3) of FIG. 27 are obtained ((1) of FIG. 28).

  In this state, it is assumed that handover of the wireless terminal device 202 existing in the femtocell FCA formed by the wireless base station device 501A to the wireless base station device 501C is attempted.

  That is, when radio base station apparatus 501A transmits a handover request to radio base station apparatus 501C, the number of handover attempts to radio base station apparatus 501C in the handover history table of radio base station apparatus 501A is updated to 7 (FIG. 28 (2)).

  After that, when the handover fails and the radio base station apparatus 501A receives a handover failure notification from the radio base station apparatus 501C, the number of successful handovers to the radio base station apparatus 501C remains 2 in the handover history table, and the handover succeeds. The rate is calculated and changed to 0.29. At this time, there is no change in the rank in the neighboring cell information both when the handover success rate is used as an index for ranking and when the number of handover success is used as an index for ranking ((3) in FIG. 28).

  In addition, when the radio base station apparatus 501A can recognize the handover source, neighboring cell information may be generated using not only the handover destination information but also the handover source information.

  Also, when the radio base station apparatus 501 finds a new base station, the radio base station apparatus 501 moves the new base station to the adjacent cell for a certain period or until the number of handover attempts to the new base station reaches a predetermined value. The neighbor cell information may be notified to the wireless terminal device 202 in addition to the information. In this case, the radio base station apparatus 501 may temporarily increase the number of base stations listed in the neighboring cell information while leaving the radio base station apparatus already listed in the neighboring cell information as it is.

  Further, the handover information acquisition unit 31 may be configured to acquire handover information indicating a handover operation history of the wireless terminal device 202 during a certain period in the past from the present. That is, the radio base station apparatus 501 may generate neighboring cell information based on a handover operation history in a certain period from the present to the past.

  For example, the radio base station apparatus 501 may generate neighboring cell information based on a handover operation history in a period from the current time to one day ago. Also, the radio base station apparatus 501 may generate neighboring cell information based on a history for a predetermined number of handovers. For example, the radio base station apparatus 501 may generate neighboring cell information based on the latest 30 previous trials of handover attempts.

  With such a configuration, for example, it is possible to prevent the rank of the radio base station apparatus 501 that has been powered off from being kept high forever.

  Further, the handover information acquisition unit 31 acquires handover information indicating the handover operation history of the radio terminal apparatus 202 for the latest certain number of times between the target base station and each of a plurality of radio base station apparatuses other than the target base station. It may be configured to. That is, the radio base station apparatus 501 may generate neighboring cell information based on the handover operation history for a certain number of times in the past from the present.

  As a specific example, in the radio base station apparatus 501A, handover information indicating the latest 30 handover operation histories of the radio terminal apparatus 202 is obtained, and the number of successful handovers from the radio base station apparatus 501A to the radio base station apparatus 501B. Is 15, the number of successful handovers from the radio base station apparatus 501A to the radio base station apparatus 501C is 5, and the number of successful handovers from the radio base station apparatus 501A to the radio base station apparatus 501C is 10. In this case, the radio base station apparatus 501A generates neighboring cell information in which the radio base station apparatus 501B is first, the radio base station apparatus 501D is second, and the radio base station apparatus 501C is third.

  Similarly to the wireless communication system according to the first to third embodiments of the present invention, the wireless base station device 501 is based on the handover operation history for a certain number of times in the past from the present, except for the target base station. The configuration may be such that neighboring cell information is generated by excluding at least radio base station apparatus 501 having a successful handover number equal to or less than a predetermined value from among a plurality of radio base station apparatuses 501.

  With such a configuration, for example, it is possible to prevent the rank of the radio base station apparatus 501 that has been powered off from being kept high forever.

  Further, when operating in the hybrid mode, the radio base station apparatus 501 may count the number of handover attempts and the number of successful handovers by performing weighting according to the member / non-member. That is, when the target base station operates in the hybrid mode, the neighboring cell information generation unit 32 weights the handover information of the registered wireless terminal device 202 and the handover information of the unregistered wireless terminal device 202, and weights Based on the result, neighboring cell information is generated.

  With such a configuration, it is possible to generate appropriate neighboring cell information according to the registered wireless terminal device 202 and the unregistered wireless terminal device 202.

  As described above, in the wireless communication system according to the fourth embodiment of the present invention, the neighboring cell information generation unit 32 performs a plurality of operations other than the target base station based on the handover information acquired by the handover information acquisition unit 31. Are ranked, and neighboring cell information is generated based on the ranking result.

  With such a configuration, it is possible to generate detailed neighboring cell information and further improve the efficiency of the operation in the radio communication system, as compared with the neighboring cell processing apparatuses according to the first to third embodiments of the present invention. it can. For example, the radio base station apparatus 501 can increase the success rate of handover by preferentially selecting an upper radio base station apparatus as a handover destination in the ranking result.

  Moreover, in the radio | wireless communications system which concerns on the 4th Embodiment of this invention, the adjacent cell information production | generation part 32 is N pieces (N is an integer greater than or equal to 1) from the top among the several radio base station apparatuses 501 ranked. The neighboring cell information indicating the wireless base station device is generated.

  With such a configuration, for example, when there is a limit on the number of radio base station apparatuses that can be included in the neighboring cell information notified to the radio terminal apparatus 202, the top N radio base station apparatuses are included in the neighboring cell information. Thus, it is possible to notify the wireless terminal device 202 of appropriate neighboring cell information.

  Moreover, in the radio | wireless communications system which concerns on the 4th Embodiment of this invention, the neighbor cell information generation part 32 produces | generates the neighbor cell information which further shows the order | rank of the ranked radio base station apparatus 501. FIG.

  With such a configuration, it is possible to generate more detailed neighboring cell information and further improve the efficiency of the operation in the radio communication system. For example, the radio terminal apparatus 202 can perform an efficient measurement operation by determining the measurement order and narrowing down the radio base station apparatuses to be measured according to the rank of the radio base station apparatus in the neighboring cell information.

  Further, in the radio communication system according to the fourth embodiment of the present invention, the neighboring cell information generation unit 32 transmits the radio terminal apparatus 202 communicating with the target base station from the radio base station apparatus 501 other than the target base station. The initial information of the neighboring cell information is generated based on the result of measuring the reception level of the radio signal for all frequencies.

  With such a configuration, it is possible to construct appropriate neighboring cell information at an early stage, and it is possible to realize an efficient operation in the wireless communication system 301 at an early stage.

  In addition, at least one of the plurality of radio base station devices 501 in the radio communication system according to the fourth embodiment of the present invention is a femto base station.

  As described above, by generating appropriate neighboring cell information in a wireless communication system in which movement of the wireless base station device and power on / off frequently occur, the effect of improving the operation efficiency in the wireless communication system is more remarkable. Can get to.

  Further, in the radio communication system according to the fourth embodiment of the present invention, the handover information acquisition unit 31 is a radio terminal apparatus between the target base station and each of a plurality of radio base station apparatuses 501 other than the target base station. The handover information indicating the success rate of the handover of 202 is acquired.

  In this way, appropriate neighbor cell information can be generated by including which radio base station device is included in the neighbor cell information and using the handover success rate as a criterion for ranking the radio base station devices.

  Further, this handover success rate may be used in place of the number of handovers in the radio communication system according to the first to third embodiments of the present invention. That is, the neighboring cell information generation unit 32 excludes at least the radio base station apparatus 501 whose handover success rate indicated by the handover information is equal to or less than a predetermined value from a plurality of radio base station apparatuses 501 other than the target base station. Generate cell information.

  With such a configuration, it is possible to appropriately delete the radio base station apparatus 501 with a small record of actual successful handover from the neighboring cell information.

  Also, in the radio communication system according to the fourth embodiment of the present invention, the neighboring cell information generation unit 32 has a high handover success rate indicated by the handover information acquired by the handover information acquisition unit 31. The neighboring cell information is generated by raising the ranking of the wireless base station apparatus 501 with a lower handover success rate.

  With such a configuration, it is possible to appropriately rank the radio base station apparatus 501 in accordance with the record of actual selection as a handover destination.

  Also, in the radio communication system according to the fourth embodiment of the present invention, the neighboring cell information generation unit 32 has a large number of successful handovers indicated by the handover information acquired by the handover information acquisition unit 31. The neighboring cell information is generated by increasing the rank of the wireless base station apparatus 501 with a lower number of successful handovers.

  With such a configuration, it is possible to appropriately rank the radio base station apparatus 501 according to the actual success of the handover.

  Note that, in the radio communication system according to the fourth embodiment of the present invention, the neighboring cell information generation unit 32 generates neighboring cell information indicating the rank of each radio base station apparatus 501 as shown in FIG. 27, for example. Although there is, it is not limited to this. It is not essential to indicate the rank of each radio base station apparatus 501 in the neighboring cell information. For example, the neighboring cell information generation unit 32 has N (N is the highest) among the plurality of radio base station apparatuses 501 ranked. When generating neighboring cell information indicating a wireless base station device of an integer of 1 or more, it is considered unnecessary to indicate the rank of each wireless base station device 501 in the neighboring cell information.

  Further, in the radio base station apparatus according to the fourth embodiment of the present invention, the neighboring cell information generation unit 32 is configured so that the radio terminal apparatus 202 communicating with the target base station is from the radio base station apparatus 501 other than the target base station. Although the configuration is such that the initial information of the neighboring cell information is generated based on the result of measuring the reception level of the transmitted radio signal for all frequencies, the present invention is not limited to this. The configuration is not limited to measuring all types of transmission frequencies of the radio base station apparatus 501 in the radio communication system, and may be configured to measure a plurality of frequencies that are a part of them.

  Moreover, in the radio | wireless communications system which concerns on the 1st-4th embodiment of this invention, an adjacent cell information generation part is based on the hand-over information acquired by the hand-over information acquisition part, several radio | wireless other than a target base station. Although it was set as the structure which produces | generates the adjacent cell information which shows the 1 or several radio | wireless base station apparatus installed in the periphery of the object base station among base station apparatuses, it is not limited to this.

  The neighbor cell information generation unit includes, in addition to the handover information indicating the handover operation history of the radio terminal apparatus, measurement information indicating the measurement result of the radio signal transmitted from the radio base station apparatus, and the attribute indicating the attribute of the radio base station apparatus The configuration may be such that neighboring cell information is generated based on a combination of information. As the measurement information, for example, the reception level and the number of times or the detection rate at which the presence of the radio base station apparatus is detected can be considered. As attribute information, for example, information on whether the radio base station apparatus is a femto base station or a macro base station can be considered.

  Further, the radio base station apparatus according to the fourth embodiment of the present invention acquires the same handover information as the femto base station according to the first embodiment of the present invention, and the radio base station apparatus in the neighboring cell information May be configured to perform ranking.

  Similarly to the gateway device according to the second and third embodiments of the present invention, in the fourth embodiment of the present invention, instead of the radio base station device 501, the gateway device 203 or the host device 205 is The structure which operate | moves as an adjacent cell processing apparatus may be sufficient.

  Further, when the radio base station apparatus has a plurality of sectors, that is, when one cell is divided into a plurality of sectors, one sector can be treated as one radio base station apparatus in the neighboring cell information. The present invention may be applied to such a case.

  Since other configurations and operations are the same as those of the wireless communication system according to the first embodiment, detailed description thereof will not be repeated here.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Fifth embodiment>
The present embodiment relates to a radio communication system in which a gateway apparatus operates as an adjacent cell processing apparatus instead of a radio base station apparatus and the contents of handover information are changed as compared with the radio communication system according to the fourth embodiment . The contents other than those described below are the same as those of the wireless communication system according to the fourth embodiment.

  FIG. 29 is a diagram illustrating an example of handover information acquired by the gateway device according to the fifth embodiment of the present invention.

  Referring to FIG. 29, gateway device 203 acquires the following handover information. That is, when the wireless terminal device 202 is handed over between the wireless base station device 501A and the wireless base station device 501C via the wireless base station device 501B, the wireless terminal device 202 performs wireless communication after the handover to the wireless base station device 501B. The time until handover to the base station apparatus 501A or the radio base station apparatus 501C, that is, the average stay time in the cell formed by the radio base station apparatus 501B is 20 seconds.

  Further, when the wireless terminal device 202 is handed over between the wireless base station device 501A and the wireless base station device 501D via the wireless base station device 501B, the wireless terminal device 202 is wireless after the handover to the wireless base station device 501B. The time until handover to base station apparatus 501A or radio base station apparatus 501D, that is, the average stay time in the cell formed by radio base station apparatus 501B is 6 seconds.

  Further, when the wireless terminal device 202 is handed over between the wireless base station device 501A and the wireless base station device 501B via the wireless base station device 501C, the wireless terminal device 202 is wireless after the handover to the wireless base station device 501C. The time until handover to base station apparatus 501A or radio base station apparatus 501B, that is, the average stay time in the cell formed by radio base station apparatus 501C is 2 seconds.

  In addition, when the wireless terminal device 202 is handed over between the wireless base station device 501A and the wireless base station device 501D via the wireless base station device 501C, the wireless terminal device 202 is wireless after the handover to the wireless base station device 501C. The time until handover to base station apparatus 501A or radio base station apparatus 501D, that is, the average stay time in the cell formed by radio base station apparatus 501C is 20 seconds.

  Further, when the wireless terminal device 202 is handed over between the wireless base station device 501A and the wireless base station device 501B via the wireless base station device 501D, the wireless terminal device 202 is wirelessly handed over to the wireless base station device 501D. The time until handover to the base station apparatus 501A or the radio base station apparatus 501B, that is, the average stay time in the cell formed by the radio base station apparatus 501D is 8 seconds.

  Further, when the wireless terminal device 202 is handed over between the wireless base station device 501A and the wireless base station device 501C via the wireless base station device 501D, the wireless terminal device 202 wirelessly operates after the handover to the wireless base station device 501D. The time until the handover to the base station apparatus 501A or the radio base station apparatus 501C, that is, the average stay time in the cell FCD formed by the radio base station apparatus 501D is 4 seconds.

  FIG. 30 is a diagram illustrating an example of neighboring cell information generated by the gateway device according to the fifth embodiment of the present invention.

  Referring to FIG. 30, using handover information as shown in FIG. 29, gateway device 203 ranks radio base station devices 501B, 501C, and 501D. That is, in the handover via the radio base station apparatus 501B with the radio base station apparatus 501A as the start point or the end point, the average stay time at the radio base station apparatus 501B is (20 seconds + 6 seconds) / 2 = 13 seconds, In the handover via the radio base station apparatus 501C with the radio base station apparatus 501A as the start point or the end point, the average stay time at the radio base station apparatus 501C is (2 seconds + 20 seconds) / 2 = 11 seconds, In the handover via the radio base station apparatus 501D with the station apparatus 501A as the start point or the end point, the average stay time at the radio base station apparatus 501D is (8 seconds + 4 seconds) / 2 = 6 seconds. The gateway device 203 calculates each of these average times, places the radio base station device 501B with the longest average time in the first place, places the radio base station device 501C with the next longest average time in the second place, and has the highest average time. The short radio base station apparatus 501D is ranked third. Then, the gateway device 203 generates neighboring cell information indicating the upper two radio base station devices 501B and 501C excluding, for example, the lowest radio base station device 501D among the ranked radio base station devices.

  Thus, in the wireless communication system according to the fifth embodiment of the present invention, the handover information acquisition unit 31 in the gateway device 203 is the first wireless of the plurality of wireless base station devices 501 other than the target base station. For the base station device and the remaining plurality of second wireless base station devices, the wireless terminal device is connected between the target base station and each of the remaining plurality of second wireless base station devices via the first wireless base station device. Shows each stay time from when the wireless terminal device 202 is handed over to the first wireless base station device to when the wireless terminal device 202 is handed over to the target base station and the remaining plurality of second wireless base station devices. Get handover information. For example, the handover information acquisition unit 31 acquires this handover information based on information from the first radio base station apparatus.

  In FIG. 29 and FIG. 30, the case where the target base station is the radio base station apparatus 501A and the first radio base station apparatus is the radio base station apparatuses 501B, 501C, and 501D is shown as an example.

  As described above, by using the stay time of the radio terminal device 202 in the radio base station device through which the radio terminal device 202 has passed at the time of handover as an evaluation criterion for ranking the radio base station devices in the neighboring cell information, an appropriate neighboring cell is obtained. Information can be generated.

  Then, the neighboring cell information generation unit 32 ranks one or more radio base station devices arranged around the target base station among a plurality of radio base station devices other than the target base station, and all Neighboring cell information is generated in which the rank of the radio base station apparatus with the long average stay time indicated by the handover information corresponding to the radio base station apparatus of 2 is higher than that of the radio base station apparatus with the short average stay time.

  With such a configuration, it is possible to appropriately rank the radio base station apparatus 501 in accordance with the necessity of passing through the radio terminal apparatus 202 in the handover operation.

  Note that, in the gateway device according to the fifth embodiment of the present invention, similarly to the gateway device according to the third embodiment of the present invention, the handover information acquisition unit communicates with the target base station 202. May be configured to acquire handover information indicating whether communication with the second radio base station apparatus is possible based on received power information from the radio terminal apparatus 202 or the like.

  Thus, in addition to the information of the handover operation history, more optimal neighboring cell information can be generated by a configuration in which information of other contents is acquired as the handover information. That is, it is possible to prevent a cell that is not actually adjacent to be recognized as if it is adjacent, and an out-of-service state from occurring.

  In the gateway apparatus according to the fifth embodiment of the present invention, for example, when the radio base station apparatus 501A is the target base station, the stay time indicated by the handover information corresponding to all the second radio base station apparatuses is Although it is configured to generate neighboring cell information in which the rank of the radio base station apparatus having a long average is set higher than that of the radio base station apparatus having a short average stay time, the present invention is not limited to this.

  The handover information acquisition unit 31 acquires the stay time for some of the second radio base station devices as handover information among all the second radio base station devices, and the adjacent cell information generation unit 32 performs this handover. The configuration may be such that the first radio base station apparatus is ranked based on the information.

  With such a configuration, it is possible to adjust the criteria for ranking the radio base station apparatus 501 in the neighboring cell information according to the installation environment of each radio base station apparatus.

  However, like the gateway device according to the fifth embodiment of the present invention, the handover information regarding all the second radio base station devices is acquired, and the neighboring cell information generation unit 32 performs the operation based on the handover information. With the configuration in which one radio base station apparatus is ranked, the first radio base station apparatus required as a handover path when a certain part of the radio base station apparatuses is used as a handover destination or a handover source, It is possible to prevent the information from being inadvertently lowered.

  Similarly, the handover information acquisition unit 31 obtains handover information indicating whether or not the wireless terminal device 202 communicating with the target base station can communicate with the second wireless base station device in each second wireless base station device. The configuration may be such that a part of the information is acquired and the neighboring cell information generation unit 32 ranks the first radio base station apparatus based on the handover information.

  Moreover, you may combine the optimization of the neighbor cell information which concerns on the 4th Embodiment of this invention, and the optimization of the neighbor cell information which concerns on the 5th Embodiment of this invention. That is, as a criterion for ranking the radio base station devices in the neighboring cell information, the number of handovers or the handover success rate of the radio terminal device 202, and the radio terminal device 202 in the radio base station device through which the radio terminal device 202 has passed at the time of handover It is also possible to combine the stay time. Further, as a criterion for determining the ranking of the radio base station apparatuses in the neighboring cell information, information on whether the radio terminal apparatus 202 can communicate with the radio base station apparatus 501 serving as a handover destination candidate is added to this combination. Is possible.

  Also, in the gateway device according to the fifth embodiment of the present invention, as a criterion for ranking the radio base station devices in the neighboring cell information, the radio terminal device in the radio base station device through which the radio terminal device 202 has passed during handover Although the configuration uses 202 staying times, the present invention is not limited to this. The configuration may be such that the number of handovers or the handover success rate is used as a criterion for ranking radio base station apparatuses in neighboring cell information.

  For example, in the gateway device according to the fifth embodiment of the present invention, as in the gateway device according to the second embodiment of the present invention, the handover information acquisition unit 31 is configured to transmit information from the target base station to other than the target base station. The number of handovers or success rate of handover of the wireless terminal device 202 to a plurality of wireless base station devices 501 and the number of handovers or successful handovers of the wireless terminal device 202 from the plurality of wireless base station devices 501 other than the target base station to the target base station The configuration may be such that handover information indicating a rate is acquired. In this case, the neighboring cell information generation unit 32 ranks the radio base station apparatus 501 based on the number of bidirectional handovers or the handover success rate between the two radio base station apparatuses 501. With such a configuration, more optimal neighboring cell information can be generated.

  In this case, the gateway device according to the fifth embodiment of the present invention may be included in at least one of the radio base station devices 501 in the radio communication system 301. In this case, the radio base station apparatus 501 equipped with the gateway apparatus 203 acquires handover information based on information from the radio terminal apparatus 202 and other radio base station apparatuses 501 that exist in the cell that the gateway apparatus 203 forms. Then, the gateway device 203 notifies the generated neighboring cell information to the wireless terminal device 202 and other wireless base station devices 501 existing in the cell formed by the gateway device 203.

  Since other configurations and operations are the same as those of the wireless communication system according to the fourth embodiment, detailed description thereof will not be repeated here.

  In the first to fourth embodiments of the present invention, the neighboring cell information generation unit is configured to generate neighboring cell information based on the handover operation history of the wireless terminal device 202. However, the present invention is not limited to this. Not what you want. The inter-base station movement (inter-cell movement) operation performed by the radio terminal apparatus 202 in the idle state is not limited to the handover which is the inter-base station movement (inter-cell movement) operation performed by the radio terminal apparatus 202 communicating with the radio base station apparatus. The present invention is also applied to.

  In this case, the radio base station apparatus includes a movement information acquisition unit instead of the handover information acquisition unit, and the movement information acquisition unit displays the movement information indicating the movement operation history of the radio terminal apparatus 202 as information from the radio terminal apparatus 202. That is, it is acquired based on the movement completion notification. Then, the neighboring cell information generation unit is installed in the vicinity of the target femto base station among the plurality of femto base stations 101 other than the target femto base station based on the movement information acquired by the movement information acquisition unit. Neighbor cell information indicating a plurality of femto base stations 101 is generated. That is, in the first to fourth embodiments of the present invention, the present invention is also applied to configurations and operations in which “handover” is replaced with “movement”.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

11, 21 Handover information acquisition unit 12, 22 Adjacent cell information generation unit 13, 23 Adjacent cell information transmission unit 31 Handover information acquisition unit 32 Adjacent cell information generation unit 33 Adjacent cell information transmission unit 34 Power measurement instruction unit 81 Base station side transmission / reception Unit 82 data processing unit 83 core network side transmission / reception unit 91 antenna 92 circulator 93 wireless reception unit 94 wireless transmission unit 95 signal processing unit 96 reception signal processing unit 97 transmission signal processing unit 101, 101A, 101B, 101C, 101D femto base station ( Radio base station equipment)
DESCRIPTION OF SYMBOLS 105 Signal processing part 106 Reception signal processing part 201 Macro base station 202 Wireless terminal device 203 Gateway apparatus 301 Wireless communication system 501 501A, 501B, 501C, 501D Wireless base station apparatus FCA, FCB, FCC, FCD Femtocell MC Macrocell

Claims (32)

An adjacent cell processing apparatus in a communication system capable of communicating with a plurality of radio base station apparatuses by performing a mobile operation of a radio terminal apparatus,
A movement information acquisition unit for acquiring movement information indicating a movement operation history of the wireless terminal apparatus based on information from at least one of the wireless terminal apparatus and the wireless base station apparatus;
Based on the movement information acquired by the movement information acquisition unit, one or more arranged around the target radio base station apparatus among the plurality of radio base station apparatuses other than the target radio base station apparatus A neighboring cell information generating unit for generating neighboring cell information indicating the wireless base station device of
An adjacent cell information transmission unit for transmitting the adjacent cell information generated by the adjacent cell information generation unit to the target radio base station device or a radio terminal device communicable with the target radio base station device, Cell processing device.   The adjacent cell information generation unit ranks a plurality of radio base station devices other than the target radio base station device based on the movement information acquired by the movement information acquisition unit, and determines the ranking result. The neighboring cell processing apparatus according to claim 1, wherein the neighboring cell information is generated based on the neighboring cell information.   The neighboring cell information generation unit generates neighboring cell information indicating N radio base station devices (N is an integer of 1 or more) from the top among the plurality of ranked radio base station devices. 2. The adjacent cell processing apparatus according to 2.   The neighboring cell processing device according to claim 2 or 3, wherein the neighboring cell information generation unit generates neighboring cell information that further indicates the ranking of the ranked radio base station devices.   The neighboring cell information generation unit is one or more of the plurality of radio base station apparatuses other than the target radio base station apparatus that are candidates for a movement destination of a radio terminal apparatus communicating with the target radio base station apparatus The neighboring cell processing apparatus according to claim 1, wherein neighboring cell information indicating a radio base station apparatus is generated.   The neighboring cell information generating unit is neighboring cell information indicating one or a plurality of the radio base station devices to be measured by the radio terminal device among the plurality of radio base station devices other than the target radio base station device. The neighboring cell processing device according to claim 1, wherein   The adjacent cell information generation unit transmits one or more of the radio base station devices other than the target radio base station device, and the radio terminal device transmits a radio signal whose reception level is to be measured. The neighboring cell processing apparatus according to claim 1, wherein neighboring cell information indicating a radio base station apparatus is generated.   The neighboring cell information generation unit is a target whose reception level is measured by the wireless terminal device that is not communicating with the target wireless base station device among the plurality of wireless base station devices other than the target wireless base station device. The neighboring cell processing device according to claim 7, wherein neighboring cell information indicating one or a plurality of the radio base station devices that transmit radio signals is generated.   The adjacent cell information generation unit is configured such that a radio terminal device communicating with the target radio base station device sets reception levels of radio signals transmitted from the radio base station devices other than the target radio base station device at a plurality of frequencies. The neighboring cell processing apparatus according to claim 2, wherein initial information of the neighboring cell information is generated based on a measurement result. The adjacent cell processing device further includes:
The target radio base station apparatus can register the radio terminal apparatus, and operates in a hybrid mode in which communication is permitted to both the registered radio terminal apparatus and the unregistered radio terminal apparatus When the wireless terminal device is not registered, the reception level of the wireless signal transmitted from the wireless base station device other than the target wireless base station device is measured at the plurality of frequencies. The adjacent cell processing apparatus according to claim 9, further comprising a power measurement instruction unit for instructing. The adjacent cell processing device further includes:
The target radio base station apparatus can register the radio terminal apparatus, and operates in a hybrid mode in which communication is permitted to both the registered radio terminal apparatus and the unregistered radio terminal apparatus If so, instruct the registered radio terminal apparatus to measure the reception level of the radio signal transmitted from the radio base station apparatus other than the target radio base station apparatus at the plurality of frequencies The adjacent cell processing device according to claim 9, further comprising a power measurement instruction unit for performing the operation.   The neighboring cell information generation unit is capable of registering the wireless terminal device by the target wireless base station device, and for both the registered wireless terminal device and the unregistered wireless terminal device. When operating in a hybrid mode that permits communication, the neighboring cell is weighted based on the weighted result by weighting the movement information of the registered wireless terminal device and the movement information of the unregistered wireless terminal device. The neighboring cell processing device according to claim 1, which generates information.   The adjacent cell processing apparatus according to claim 1, wherein the movement information acquisition unit acquires movement information indicating a movement operation history of the wireless terminal apparatus during a certain period from the present to the past.   The adjacent cell processing apparatus according to claim 1, wherein at least one of the plurality of radio base station apparatuses in the communication system is a femto base station.   The movement information acquisition unit acquires movement information indicating the number of movements of a radio terminal apparatus between the target radio base station apparatus and each of the plurality of radio base station apparatuses other than the target radio base station apparatus. Item 15. The adjacent cell processing device according to any one of Items 1 to 14.   The movement information acquisition unit includes the number of movements of a radio terminal device from the target radio base station device to a plurality of radio base station devices other than the target radio base station device, and a plurality of the other than the target radio base station device. The adjacent cell processing apparatus according to claim 15, wherein movement information indicating the number of movements of the radio terminal apparatus from the radio base station apparatus to the target radio base station apparatus is acquired.   The neighboring cell information generation unit excludes at least the radio base station apparatus in which the number of movements indicated by the movement information is a predetermined value or less from among the plurality of radio base station apparatuses other than the target radio base station apparatus The neighboring cell processing apparatus according to claim 15 or 16, wherein the neighboring cell information is generated.   The adjacent cell information generation unit ranks a plurality of radio base station devices other than the target radio base station device based on the movement information acquired by the movement information acquisition unit, and in the ranking, The adjacent cell processing device according to any one of claims 15 to 17, wherein a rank of the radio base station device having a large number of movements indicated by the movement information is increased as compared to the radio base station device having a small number of movements. .   The movement information acquisition unit indicates the latest movement operation history of the radio terminal apparatus for a predetermined number of times between the target radio base station apparatus and each of the plurality of radio base station apparatuses other than the target radio base station apparatus. The adjacent cell processing apparatus according to any one of claims 15 to 18, which acquires movement information.   The movement information acquisition unit acquires movement information indicating a success rate of a movement operation of a radio terminal apparatus between the target radio base station apparatus and each of the plurality of radio base station apparatuses other than the target radio base station apparatus The adjacent cell processing apparatus according to claim 1, wherein   The movement information acquisition unit includes a success rate of a movement operation of a radio terminal device from the target radio base station device to a plurality of radio base station devices other than the target radio base station device, and other than the target radio base station device. The adjacent cell processing apparatus according to claim 20, wherein movement information indicating a success rate of a movement operation of a radio terminal apparatus from a plurality of radio base station apparatuses to the target radio base station apparatus is acquired.   The neighboring cell information generation unit is configured to select the radio base station apparatus in which a success rate of the moving operation indicated by the movement information is a predetermined value or less from a plurality of the radio base station apparatuses other than the target radio base station apparatus. The neighboring cell processing apparatus according to claim 20 or 21, wherein at least the neighboring cell information excluded is generated.   The adjacent cell information generation unit ranks a plurality of radio base station devices other than the target radio base station device based on the movement information acquired by the movement information acquisition unit, and in the ranking, The rank of the radio base station apparatus with a high success rate of the movement operation indicated by the movement information is raised higher than the radio base station apparatus with a low success rate of the movement operation. The adjacent cell processing apparatus as described.   The movement information acquisition unit, for the first radio base station device and the second radio base station device among the plurality of radio base station devices other than the target radio base station device, the target radio base station device and the When the wireless terminal device moves between the second wireless base station devices via the first wireless base station device, the target wireless base after the wireless terminal device moves to the first wireless base station device The adjacent cell processing apparatus according to any one of claims 1 to 23, wherein movement information indicating a staying time until moving to a station apparatus or the second radio base station apparatus is acquired.   The neighboring cell information generation unit is configured to select the first radio base station apparatus in which the stay time indicated by the movement information is a predetermined value or less from among the plurality of radio base station apparatuses other than the target radio base station apparatus. The neighboring cell processing device according to claim 24, wherein at least the neighboring cell information excluded is generated.   The adjacent cell information generation unit ranks a plurality of radio base station devices other than the target radio base station device based on the movement information acquired by the movement information acquisition unit, and in the ranking, The adjacent cell processing apparatus according to claim 24 or 25, wherein the rank of the radio base station apparatus having a long stay time indicated by the movement information is higher than that of the radio base station apparatus having a short stay time.   The movement information acquisition unit is configured to provide the target radio base for the first radio base station device and the remaining second radio base station devices among the plurality of radio base station devices other than the target radio base station device. When the wireless terminal device moves between the station device and each of the plurality of second wireless base station devices via the first wireless base station device, the wireless terminal device is the first wireless base station. 27. Any one of claims 24 to 26, wherein movement information indicating each staying time from moving to a device to moving to the target wireless base station device and the plurality of second wireless base station devices is acquired. The adjacent cell processing apparatus described in 1.   The neighboring cell information generation unit has a predetermined stay time indicated by the movement information for all of the plurality of second radio base station devices from among the plurality of radio base station devices other than the target radio base station device. The adjacent cell processing apparatus according to claim 27, wherein the adjacent cell information excluding at least the first radio base station apparatus that is equal to or less than a value is generated.   The movement information acquisition unit further acquires movement information indicating whether or not a radio terminal apparatus communicating with the target radio base station apparatus can communicate with the second radio base station apparatus. The adjacent cell processing apparatus according to any one of claims.   The neighboring cell information generation unit communicates with the target radio base station apparatus when the stay time indicated by the movement information is a predetermined value or less from among the plurality of radio base station apparatuses other than the target radio base station apparatus 30. The neighboring cell processing apparatus according to claim 29, wherein the neighboring cell processing apparatus generates the neighboring cell information excluding at least the first wireless base station apparatus when a wireless terminal apparatus capable of communicating with the second wireless base station apparatus is enabled. .   The adjacent cell processing apparatus according to any one of claims 1 to 30, wherein the adjacent cell processing apparatus is included in one or a plurality of the radio base station apparatuses. An adjacent cell processing method in a communication system capable of communicating with a plurality of radio base station apparatuses by performing a mobile operation of a radio terminal apparatus,
Acquiring movement information indicating a movement operation history of the wireless terminal device based on information from at least one of the wireless terminal device and the wireless base station device;
One or a plurality of the radio base station devices arranged around the target radio base station device among the plurality of radio base station devices other than the target radio base station device based on the acquired movement information Generating neighboring cell information indicating
Transmitting the generated neighboring cell information to the target radio base station apparatus or a radio terminal apparatus communicable with the target radio base station apparatus.

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