JP2011135147A - Base station device and heterogeneous radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the operating cost of a base station device network by positively shifting the mode of a base station device to a power-saving mode corresponding to temporal or geographical traffic distribution. <P>SOLUTION: It is determined whether an index indicating the operation cost for an access amount from a terminal device exceeds a first threshold. When the index exceeds the first threshold as the result of the determination, the mode of the base station device is shifted to the power saving mode by a condition that simultaneously satisfies the items where a neighboring base station device present around a self-station, when the self-station is shifted to the power-saving mode, can reflect the cell range of the neighboring base station device to the cell range of own station; and an access amount does not exceed the allowable limit of the neighboring base station device, when a terminal device accessing own station changes the access destination to the neighboring base station device. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is applied to a heterogeneous wireless communication system that performs wireless communication using a plurality of types of wireless communication methods at the same time, and in particular, an active mode that performs communication with a terminal device and a power saving mode that does not perform communication with the terminal device It relates to the technology to switch between.

  Conventionally, techniques for integrating different wireless systems such as a wireless LAN and a mobile phone have been proposed. For example, Patent Document 1 discloses a technique for integrating different types of radio systems having different cell sizes such as a pico cell, a micro cell, and a macro cell using a cognitive base station device and a cognitive terminal device. The cognitive base station device and the cognitive terminal device each include a switch, a plurality of wireless modules, and a wireless environment recognition unit. The wireless environment recognition unit recognizes the wireless environment and links to the switch based on the recognition result. Instructs the wireless module to which the frame is distributed. The link frame is transmitted / received via the designated wireless module.

JP 2008-85759 A

  In mobile radio communications, third generation systems such as W-CDMA (Wideband Code Division Multiple Access) and CDMA2000 (Code Division Multiple Access 2000), HSDPA (High Speed Downlink Packet Access), HRPD (High Rate Packet Data) and the like 3.9 generation systems such as 3.5 generation systems, WiMAX (Worldwide Interoperability for Microwave Access), LTE (Long Term Evolution), etc. appear one after another, and they are actively used.

  In the past development from the first generation to the second generation and from the second generation to the third generation, the use of the old generation system is stopped and the so-called “winding” is performed to completely move to the new generation. It was. However, the generations after the third generation are not necessarily intended to be “rolling up”, but have an aspect of introducing new applications such as high-speed data communication. As the new generation system is put into practical use, the frequency bands used are increasing to 800 MHz, 1.5 GHz, 1.7 GHz, 2 GHz, and 2.5 GHz.

  As a result, the number of base station devices increases. For example, the power consumption of the base station apparatus varies depending on the coverage. For example, there are products of about 300 to 500 W in the third generation system, about 200 to 300 W in the 3.9 generation system, and about 10 W in the outdoor wireless LAN. is doing. In the future, there is a concern that the total amount of power consumption of the base station apparatus will increase further.

  The present invention has been made in view of such circumstances, and by actively shifting the base station apparatus to the power saving mode according to the temporal or geographical traffic distribution, the base station apparatus network It is an object of the present invention to provide a base station apparatus and a heterogeneous wireless communication system that can realize a reduction in operating costs.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, the base station apparatus of the present invention is applied to a heterogeneous radio communication system that performs radio communication using a plurality of types of radio communication systems at the same time, and performs communication between the active mode for communicating with the terminal apparatus and the terminal apparatus. A base station apparatus that switches between a power saving mode and a terminal apparatus that determines whether or not an index indicating an operation cost with respect to an access amount from a terminal apparatus exceeds a first threshold, and as a result of the determination, the index is the first If the threshold value of the local station is exceeded, the neighboring base station device existing in the vicinity of the local station when the local station shifts to the power saving mode can extend the cell range of the neighboring base station device to the cell range of the local station. And that the access amount does not exceed the allowable limit of the neighboring base station device when the terminal device accessing the own station changes the access destination to the neighboring base station device, Subject to be satisfied at the same time, characterized in that it shifts to the power saving mode.

  As described above, when the index indicating the operation cost with respect to the access amount from the terminal device exceeds the first threshold, when the local station shifts to the power saving mode, neighboring base station devices existing around the local station It is possible to extend the cell range of the neighboring base station device to the cell range of the own station, and the access amount when the terminal device accessing the own station changes the access destination to the neighboring base station device but it does not exceed the permissible limit of the neighboring base station apparatus, the condition that satisfies the same time, shifts to the power saving mode. As a result, the base station device that covers the coverage area is left in the active mode, and the base station device of the local station is shifted to the power saving mode. Only the station device can remain active. As a result, a reduction in operation cost can be realized.

  (2) In addition, the base station apparatus of the present invention stores an area map indicating the maximum coverage of the own station and neighboring base station apparatuses, and performance information including the maximum transmission power, antenna gain, and antenna height of the own station and neighboring base station apparatuses. The index is calculated with reference to the area map or the database.

  As described above, since an area map indicating the maximum coverage of the own station and the neighboring base station apparatus and a database for storing performance information including the maximum transmission power, the antenna gain, and the antenna height of the own station and the neighboring base station apparatus are provided, an optimum index is provided. Can be calculated.

  (3) Further, the base station apparatus of the present invention transmits a power saving mode transition notification indicating transition to the power saving mode to a neighboring base station apparatus.

  Thus, since the power saving mode transition notification indicating the transition to the power saving mode is transmitted to the neighboring base station apparatus, the neighboring base station apparatus grasps that the own station shifts to the power saving mode. be able to. As a result, the neighboring base station device does not perform a special process when it already covers its own coverage, and can perform a process to increase the transmission output when it does not cover its own coverage. it can. Thereby, even if the local station shifts to the power saving mode, the operation of the system can be continued.

  (4) Further, the base station apparatus of the present invention is applied to a heterogeneous radio communication system that performs radio communication using a plurality of types of radio communication schemes at the same time. A base station device that switches between a power saving mode in which communication is not performed, and an area map indicating the maximum coverage of the base station and neighboring base station devices existing around the local station and the maximum transmission power of the base station and the neighboring base station device, A database for storing performance information including antenna gain and antenna height; and determining whether or not an access amount from a terminal device exceeds a second threshold value. As a result of the determination, the access amount is less than or equal to the second threshold value. If it exceeds, the neighboring base station device that has shifted to the power saving mode is moved to the neighboring cell station's cell range when the neighboring base station device has shifted to the active mode. And the amount of access exceeds the allowable limit of the neighboring base station device when the terminal device accessing the own station changes the access destination to the neighboring base station device. In other words, an active mode shift request for transmitting a request to shift to the active mode is transmitted to the neighboring base station apparatus that has shifted to the power saving mode on the condition that both of the above conditions are satisfied at the same time.

  As described above, when the access amount exceeds the second threshold value, the neighboring base station device in the cell range of the own station when the neighboring base station device that has shifted to the power saving mode is shifted to the active mode. And the amount of access exceeds the allowable limit of the neighboring base station device when the terminal device accessing the own station changes the access destination to the neighboring base station device. The active mode shift request for requesting to shift to the active mode is transmitted to the neighboring base station apparatus that has shifted to the power saving mode on the condition that both of the above are satisfied at the same time. As a result, when access concentrates on the own station and a decrease in throughput is expected, the neighboring base station apparatus in the power saving mode can be set to the active mode, so that access can be distributed. As a result, it is possible to improve the throughput and reduce the operation cost in the entire system.

  (5) Further, the base station apparatus of the present invention is characterized in that the transmission output is reduced after transmitting the active mode shift request.

  Thus, since the transmission output is reduced after transmitting the active mode transition request, the operation cost can be reduced.

  (6) Also, the base station apparatus of the present invention is applied to a heterogeneous radio communication system that performs radio communication using a plurality of types of radio communication schemes at the same time. A base station apparatus for switching to a power saving mode in which communication is not performed, and during the transition to the power saving mode, the active mode transition request is issued from the base station apparatus described in (4) or (5) above. When received, the mode is shifted to the active mode.

  In this way, when an active mode transition request is received from another neighboring base station device, the mode is shifted to the active mode. Therefore, when access is concentrated in other neighboring base station devices and a decrease in throughput is expected, power saving is achieved. The local station in the mode can be set to the active mode. As a result, access can be distributed, and throughput can be improved and operation costs can be reduced throughout the system.

  (7) The heterogeneous radio communication system of the present invention is a heterogeneous radio communication system that performs radio communication using a plurality of types of radio communication systems at the same time, and includes at least one terminal device and (1) to ( 3) and the base station apparatus according to any one of (4) to (6) above, each base station apparatus including its own station and its surroundings And an area map indicating the maximum coverage of neighboring base station apparatuses and performance information including maximum transmission power, antenna gain, and antenna height of the local station and neighboring base station apparatuses.

  As described above, the area map indicating the maximum coverage of the base station and neighboring base station devices existing around the base station and the performance information including the maximum transmission power, antenna gain, and antenna height of the base station and the neighboring base station device Since transmission / reception is performed, any one of the base station apparatuses can be shifted from the active mode to the power saving mode, or can be shifted from the power saving mode to the active mode. As a result, it is possible to reduce the operating cost of the base station apparatus network.

  According to the present invention, the operation cost can be reduced by the autonomous processing of the base station apparatus across multiple radio systems. That is, the base station apparatus that covers the coverage is left in the active mode, and the other base station apparatus is shifted to the power saving mode. Depending on the amount of access changes from the terminal device, leaving only the minimum necessary base station apparatus in the active state.

It is a figure which shows the structure of the radio | wireless communications system which concerns on this embodiment. It is a block diagram which shows schematic structure of the base station apparatus which concerns on this embodiment. It is a block diagram which shows schematic structure of the mobile station apparatus which concerns on this embodiment. It is a figure which shows the relationship of the radio | wireless connection of a base station apparatus and a mobile station apparatus. It is a figure which shows the concept of this invention. It is a flowchart which shows operation | movement of the base station apparatus in active mode. It is a figure which shows the sequence of the operation | movement shown in FIG. It is a flowchart which shows operation | movement of the base station apparatus in active mode. It is a figure which shows the sequence of the operation | movement of FIG. It is a flowchart which shows operation | movement of the base station apparatus in power saving mode.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration of a wireless communication system according to the present embodiment. FIG. 2 is a block diagram illustrating a schematic configuration of the base station apparatus according to the present embodiment, and FIG. 3 is a block diagram illustrating a schematic configuration of the mobile station apparatus (terminal apparatus) according to the present embodiment. In this specification, the base station apparatus can switch between an active mode in which communication with the terminal apparatus is performed and a power saving mode in which communication with the terminal apparatus is not performed.

  As shown in FIG. 1, the network of the radio communication system according to the present embodiment includes a macro cell by a macro cell radio module 14 a, a micro cell radio module 14 b, a pico cell radio module 14 c, a mobile station device 100, and a switch 13.

  As shown in FIG. 2, the base station apparatus 10 includes a core network side interface 11, a virtual MAC processing unit 12, a switch 13, a macro cell radio module 14a, a micro cell radio module 14b, a pico cell radio module 14c, a radio environment recognition. The unit 15 and the sensor 16 are included. In addition, although the base station apparatus 10 has the virtual MAC process part 12, it is not necessarily limited to this. The base station apparatus 10 controls the switch 13 so as to select an optimal wireless module based on information such as communication quality acquired by the wireless environment recognition unit 15.

  As shown in FIG. 3, the mobile station device 100 includes a user network side interface 101, a virtual MAC processing unit 102, a switch 103, a macro cell radio module 104a, a micro cell radio module 104b, a pico cell radio module 104c, a radio environment recognition. The unit 105 and the sensor 106 are included. The mobile station apparatus 100 has a virtual MAC processing section 102 is not limited thereto. The mobile station device 100 controls the switch 103 so as to select an optimal wireless module based on information such as communication quality acquired by the wireless environment recognition unit 105.

  Figure 4 is a diagram showing the relationship of the radio connection of the base station apparatus (FIG. 2) and the mobile station device (FIG. 3). The same type of wireless module is connected between the base station apparatus and the mobile station apparatus.

  In this specification, each of the macro cell radio module 14a, the micro cell radio module 14b, and the pico cell radio module 14c on the base station apparatus side is regarded as a single base station apparatus and can communicate with each other via the switch 13. .

  FIG. 5 is a diagram showing the concept of the present invention. In FIG. 5, one macro cell base station device, three micro cell base station devices, and 13 pico cell base station devices coexist. Assuming that the macro cell base station device, the micro cell base station device, and the pico cell base station device have power consumption in the active mode of 500 W, 200 W, and 40 W, respectively, 1,620 W is consumed when all 17 stations are in the active mode. Assuming that the power consumption in the power saving mode is 0 W, when only two micro cell base station devices and seven pico cell base station devices in FIG. 5 are in the active mode, the sum of their power consumption is 680 W, It is 40% with respect to 1,620 W shown above. When the power consumption is regarded as the operation cost as it is, the operation cost is reduced by 60%. However, even with high power consumption, base station devices used by many terminal devices should remain in the active mode, and the access amount (traffic amount) needs to be considered. Therefore, in this paper, an index representing the operation cost per access amount from the terminal device is provided, and based on this, the base station device shifts between modes.

  FIG. 6 is a flowchart showing the operation of the base station apparatus in the active mode. This operation shows a procedure in which the base station device autonomously shifts to the power saving mode when the index representing the operation cost per access amount from the terminal device exceeds a certain value. In this embodiment, the base station apparatus has an area map indicating the maximum coverage of the own station and neighboring base station apparatuses, or a database that holds performance information such as maximum transmission power, antenna gain, and antenna height.

  When the base station apparatuses are connected to each other and the above-described information is updated, the base station apparatuses notify the neighboring base station apparatuses, and mutually update the area map and the database (step S1). The information held by both parties is as follows.

  “Area map” The neighboring base station apparatus list and the maximum coverage of each station including the own station are marked and held with coordinates.

“Database” The neighboring base station apparatus list and the following information of each station including the own station are held.
・ Maximum transmission power, antenna gain, antenna height, etc. ・ Indicator representing operation cost per access I = C ÷ A
Operation cost index I: A function having power consumption, coverage, capacity, and the like as parameters.
Access amount from terminal device A: Access traffic amount from terminal device

  Next, the index is compared with a threshold value (step S2). If the index I is higher than the threshold, indicating that the operating costs per amount of access that base station apparatus is expensive. On the contrary, when the index I is lower than the threshold value, it indicates that the cost is low. The state of the base station apparatus is controlled so that the index I becomes low.

  The operation cost C of the base station apparatus may be updated as appropriate when the power consumption or the like changes. A base station apparatus capable of realizing wide area coverage such as a macro cell may set C to a relatively lower value than a base station apparatus with narrow area coverage. As the access amount A from the terminal device, the user traffic amount transmitted per unit time may be used. The unit time may be appropriately changed according to the region / time. Alternatively, the change in the access amount A for each time may be acquired in advance and held and used as a database.

In this embodiment, the base station apparatus has an active mode and a power saving mode, and performs the following operations.
-In the power saving mode, sleep and stop (stop transmission / reception).
・ Transfer to active mode by external trigger and start transmission / reception.

  [Procedure 1] The base station apparatus monitors the index. As an example of the index, the above-mentioned “index I = operating cost C of base station apparatus ÷ access amount A from terminal apparatus” can be considered.

  [Procedure 2] When this index exceeds a threshold value, the base station apparatus shifts to a power saving mode.

  [Procedure 3] Communicates with neighboring base station apparatuses and collects information. It is determined whether or not the following conditions are satisfied (step S3). If the conditions are satisfied, the process shifts to the power saving mode. If not satisfied, the process returns to step 1.

  (A) When the own station shifts to the power saving mode, the neighboring base station apparatus can cover the coverage.

  (I) When the neighboring base station apparatus has already been covered, the neighboring base station apparatus does not perform special processing.

  (Ii) In cases other than (i), the neighboring base station apparatus (one or more) adjusts the transmission output.

  (B) Even if the traffic of the local station moves to the neighboring base station device, it does not exceed the allowable limit of the neighboring base station device.

  (I) the amount of access access amount + proximate base station apparatus of the own station <allowable amount of access proximate base station apparatus, to meet.

  These determinations may be made with reference to the aforementioned area map or database. By referring to the area map, a search is made for a combination of one or a plurality of base station apparatuses that can compensate for the coverage of the local station. Further access amount A in the database, with reference to the capacity, narrow down the possible combinations accommodate access of own station. For each combination of candidate base station apparatuses, the sum (ΣI) of the indices after the transition is obtained. The base station apparatus that supports the combination that minimizes the sum is selected. The index is regarded as an area that includes a plurality of base station devices, and the aim is not to increase the index I after the transition as an area. If the sum (ΣI) of the index values after the transition exceeds that before the transition, the transition is postponed. For quick transition, ΣI for each combination may be constantly updated.

  (C) When the neighboring base station apparatus is in the transition procedure in advance, the execution of the transition procedure of the own station is stopped and the procedure of the neighboring base station apparatus is executed.

  In addition, when the neighboring base station apparatus is in the procedure of shifting to the power saving mode, it may be provided that the power saving effect of the own station is higher than that of the neighboring base station apparatus. That is, satisfy the power saving effect of the local station> the power saving effect of the neighboring base station device.

  For this purpose, each base station apparatus notifies the neighboring base station apparatus via the network that the transition procedure is in progress at the start and end of the transition procedure. The neighboring base station apparatus list to be notified is held and updated in the database in the previous section. By receiving this notification, it is understood that the neighboring base station device is in the transition procedure.

  [Procedure 4] A handover (intra-system, Inter RAT) may be instructed to a terminal device under control (step S4). However, even if the procedure 4 is not explicitly performed, the terminal device can move to another base station device along a normal handover procedure.

  [Procedure 5] The base station apparatus notifies the neighboring base station apparatus to shift to the power saving mode via the “power saving mode shift notification” (step S5). This is notified with reference to the neighboring base station apparatus list in the database.

  [Procedure 6] The base station apparatus reduces the transmission output (step S6). Depending on the situation, the neighboring base station apparatus increases the transmission power.

  [Procedure 7] The base station apparatus shifts to a process in the power saving mode (see FIG. 10) (step S7).

  FIG. 7 is a diagram showing a sequence of the operations shown in FIG. In FIG. 7, the base station apparatus notifies the neighboring base station apparatus of the state of the own station periodically or irregularly via “base station apparatus state notification” (step S10). Information to be notified includes a wireless system identifier, base station apparatus ID, transmission output, antenna gain, coverage information, and traffic status (instantaneous value of throughput being processed and differential value (trend of change)). The own base station device and the neighboring base station device are allowed to belong to the same radio system or different radio systems. The base station (own station) updates the index (step S11), and compares the index with a threshold value (step S12). Meanwhile, the base station apparatus and the neighboring base station apparatus mutually notify the base station state (step S13).

  Next, when the index is not larger than the threshold value in step S12, the process proceeds to step S10. On the other hand, when the index is larger than the threshold value, it is determined whether or not to shift to the power saving mode as described above (step S14). When the transition is canceled, the process proceeds to step S10. When the transition is performed, a handover instruction may be issued to the terminal device (step S15). In accordance with a normal handover procedure, the terminal device moves to the neighboring base station device by starting an intra-system handover if the neighboring base station device is the same system as the own station, and if the neighboring base station device belongs to a different system, an InterRAT handover. Further, the base station (own station) issues a power saving mode transition notification (step S16), decreases the transmission output (step S17), and the base station (neighboring) increases the transmission output (step S18). Then, the base station (own station) shifts to the power saving mode (step S19), and performs processing in the power saving mode.

(Second Embodiment)
FIG. 8 is a flowchart showing the operation of the base station apparatus in the active mode. This operation is a procedure for shifting a base station apparatus (referred to as a support base station apparatus) in a neighboring power saving mode to an active mode when traffic is concentrated.

  [Procedure 1] The traffic amount of the own station (access amount from the terminal device) is monitored (step S30).

  [Procedure 2] It is determined whether or not the traffic volume has exceeded a threshold value (step S32).

  [Procedure 3] A base station apparatus in a power saving mode that can support the concentration of traffic is searched for as a candidate base station apparatus (step S33). Based on the transmission power, coverage, traffic capacity, etc. of the candidate base station apparatus, the base station apparatus determines whether to change the transmission output of the own station and shift to the active mode. In the supporting base station apparatus, user traffic is transferred from adjacent stations surrounding the supporting base station apparatus. A base station apparatus having an allowable access amount exceeding the inflow access amount needs to be selected. In addition, since there are a plurality of candidate support base station apparatuses, it is necessary to narrow down.

  This is based on “allowable access amount for each base station device” and “maximum transmission power of base station device” as constraints, “access amount flowing from peripheral station to candidate station”, “transition from peripheral station to candidate station” For the combination of “coverage area”, it can be reduced to the problem of minimizing “sum of related base station apparatus index I (ΣI)”. After obtaining the solution for each candidate base station apparatus, the supporting base station apparatus is determined by selecting the candidate base station apparatus that minimizes ΣI. As a heuristic simple method, the following method may be used.

  [Procedure 3-1] On the premise that a cell boundary is set to ½ of the distance between the candidate station and its adjacent station, the coverage to be transferred from the adjacent station to the candidate station is determined. However, the upper limit of coverage to be transferred is defined by the maximum transmission power of the base station apparatus.

[Procedure 3-2] It is assumed that the access amount is uniformly distributed in the coverage. The access amount flowing into the candidate station from its adjacent station is obtained from the area ratio of the coverage to be transferred.
(Inflow access amount) = (Access amount of adjacent station) x (Transition area) ÷ (Adjacent station area before transition)
Here, the sum of the inflow access amounts is set to be equal to or less than the allowable access amount of the candidate base station apparatus.

  [Procedure 3-3] For each candidate base station apparatus, the sum of evaluation indices I of the candidate base station apparatus and the adjacent base station apparatus is obtained.

  [Procedure 3-4] Select a candidate base station apparatus in which the result of Procedure 3-3 takes the minimum value.

  Information used in these methods is notified in advance between base station apparatuses via a network and reflected in the database.

  Transmits the "active mode shift request" in the Step 4] The base station apparatus determined in step 3 (step S34).

  [Procedure 5] If it is determined in the procedure 3 that the transmission output of the own station has been changed, the transmission output is reduced accordingly (step S35).

  [Procedure 6] The neighboring base station apparatus increases the transmission output and completes the transition to the active mode.

  Note that the own base station device and the neighboring base station device are allowed to belong to the same radio system or different radio systems. In accordance with a normal handover procedure, the terminal device moves to the neighboring base station device by starting an intra-system handover if the neighboring base station device is the same system as the own station, and if the neighboring base station device belongs to a different system, an InterRAT handover.

  FIG. 9 is a diagram showing a sequence of the operation of FIG. The base station (own station) monitors the traffic (step S40) and determines whether the traffic volume exceeds the threshold (step S41). If the traffic volume does not exceed the threshold, the process proceeds to step S40. If the traffic volume exceeds the threshold, the neighboring base station apparatus in the power saving mode is determined from the neighboring base station apparatuses, and the own station Is determined to be changed (step S42). The base station (own station) makes an active mode transition request to the neighboring base station device (step S43). Then, the base station (own station) decreases the transmission output (step S44), and the neighboring base station apparatus increases the transmission output (step S45).

(Third embodiment)
FIG. 10 is a flowchart showing the operation of the base station apparatus in the power saving mode. This operation indicates a procedure in which the base station apparatus in the power saving mode shifts to the active mode in accordance with the active mode shift request from the neighboring base station apparatus shown in FIG.

  [Procedure 1] An “active mode transition request” is received from a neighboring active mode base station apparatus (step S50).

  [Procedure 2] The transmission output is increased to shift to the active mode (step S51).

  [Procedure 3] The processing shown in FIGS. 6 to 9 is started as processing in the active mode (step S52).

  The own base station device and the neighboring base station device are allowed to belong to the same radio system or different radio systems. In accordance with a normal handover procedure, the terminal device moves to the neighboring base station device by starting an intra-system handover if the neighboring base station device is the same system as the own station, and if the neighboring base station device belongs to a different system, an InterRAT handover.

  As described above, according to the present embodiment, it is possible to realize a reduction in operation cost by the autonomous processing of the base station apparatus across multiple radio systems. That is, the base station apparatus that covers the coverage is left in the active mode, and the other base station apparatus is shifted to the power saving mode. Depending on the amount of access changes from the terminal device, leaving only the minimum necessary base station apparatus in the active state.

DESCRIPTION OF SYMBOLS 10 Base station apparatus 11 Core network side interface 12 Virtual MAC processing part 13 Switch 14a Macro cell radio module 14b Micro cell radio module 14c Pico cell radio module 15 Radio environment recognition part 16 Sensor 100 Mobile station apparatus 101 Core network side interface 102 Virtual MAC Processing unit 103 Switch 104a Macro cell radio module 104b Micro cell radio module 104c Pico cell radio module 105 Radio environment recognition unit 106 Sensor

Claims (7)

A base station apparatus that is applied to a heterogeneous wireless communication system that performs wireless communication using a plurality of types of wireless communication systems at the same time, and switches between an active mode that communicates with a terminal apparatus and a power saving mode that does not communicate with the terminal apparatus Because
It is determined whether an index indicating an operation cost with respect to an access amount from the terminal device exceeds a first threshold. If the index exceeds the first threshold as a result of the determination, the local station determines that the power saving mode is When the neighboring base station device existing in the vicinity of the own station when the mobile station has shifted to, it is possible to extend the cell range of the neighboring base station device to the cell range of the own station, and the terminal that has accessed the own station When the apparatus changes the access destination to the neighboring base station apparatus, the access amount does not exceed the allowable limit of the neighboring base station apparatus, and the apparatus shifts to the power saving mode on condition that the conditions satisfy simultaneously that Base station equipment.   An area map indicating the maximum coverage of the local station and neighboring base station apparatus and a database storing performance information including the maximum transmission power, antenna gain, and antenna height of the local station and the neighboring base station apparatus, and referring to the area map or the database The base station apparatus according to claim 1, wherein the index is calculated.   The base station apparatus according to claim 1 or 2, wherein a power saving mode transition notification indicating transition to the power saving mode is transmitted to a neighboring base station apparatus. A base station apparatus that is applied to a heterogeneous wireless communication system that performs wireless communication using a plurality of types of wireless communication systems at the same time, and switches between an active mode that communicates with a terminal apparatus and a power saving mode that does not communicate with the terminal apparatus Because
An area map indicating the maximum coverage of the base station and neighboring base station devices existing in the vicinity of the base station and a database storing performance information including the maximum transmission power, antenna gain, and antenna height of the base station and the neighboring base station device;
It is determined whether or not the access amount from the terminal device exceeds a second threshold, and if the access amount exceeds the second threshold as a result of the determination, the neighboring base station that has shifted to the power saving mode When the device is shifted to the active mode, it is possible to extend the cell range of the neighboring base station device to the cell range of the own station, and the terminal device accessing the own station makes the access destination the neighboring On the condition that the access amount does not exceed the permissible limit of the neighboring base station device when changing to the base station device, the neighboring base station device transitioning to the power saving mode on the condition that A base station apparatus which transmits an active mode transition request for requesting transition to an active mode.   After transmitting the active mode transition request, the base station apparatus according to claim 4, wherein reducing the transmission output. A base station apparatus that is applied to a heterogeneous wireless communication system that performs wireless communication using a plurality of types of wireless communication systems at the same time, and switches between an active mode that communicates with a terminal apparatus and a power saving mode that does not communicate with the terminal apparatus Because
6. The base station apparatus that shifts to the active mode when the active mode shift request is received from the base station apparatus according to claim 4 or 5 during the shift to the power saving mode. . A heterogeneous wireless communication system that performs wireless communication using a plurality of types of wireless communication methods simultaneously,
At least one terminal device;
A base station apparatus according to any one of claims 1 to 3,
And an area map indicating maximum coverage of the base station and neighboring base station devices existing around the base station, and the base station device according to any one of claims 4 to 6. A heterogeneous wireless communication system, wherein performance information including maximum transmission power, antenna gain, and antenna height of a local station and a neighboring base station apparatus is transmitted and received between each other.

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