JP2008252809A - Radio base station, centralized control station, and mobile station - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication system in which a processing load on a centralized control station can be reduced and a radio system can be changed without disconnecting a mobile station under communication. <P>SOLUTION: A radio base station performing radio communication with a mobile station whose radio system can be changed, includes: a radio communication means which is capable of changing the radio system; a change request receiving means which receives a radio system change request from the mobile station; and a radio system control means which determines whether the radio system can be changed in response to the change request. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio communication system including a plurality of radio base stations whose radio systems can be changed, which performs radio communication with a plurality of mobile stations whose radio systems can be changed.

  In recent years, wireless systems having various characteristics have been developed, and users can enjoy a comfortable communication environment by properly using them. However, it is difficult for a radio base station to support all the radio systems included in a mobile station used by a user, and it is included even when the radio system is implemented limited to several radio systems. When a wireless system other than the wireless system is developed, a new wireless base station must be installed. For this reason, the introduction cost of a new wireless communication system remains high and becomes a high barrier to the introduction of highly convenient services.

For example, in Patent Document 1, as a solution to the above-described problems, the installed radio base station mainly includes only an antenna unit, and the modem unit is implemented in a centralized control station that supervises the radio base station. Thus, the installation cost and operation cost of the wireless communication system are reduced. In the central control station, the digital signal processing unit is configured by a digital signal processor (DSP), and the wireless system is realized by software (hereinafter, this technology is referred to as software wireless technology). Therefore, even when a new wireless system is introduced, it can be dealt with only by rewriting software. In addition, since the simple wireless base station has only the antenna port, the hardware is not changed, and the operation cost can be reduced.
JP 2000-152300 A

  In the above-described technology, the radio communication system is simplified by dividing the radio communication system into the antenna unit and the other parts and assigning roles to the radio base station and the centralized control station. In addition, since the signal processing part related to the radio system is realized by using software radio technology in the centralized control station, it is easy to update the radio system.

  However, according to such function sharing, it is possible to simplify and reduce the cost of the radio base station. For example, when the number of radio base stations under the control of the central control station increases, the signal processing load on the central control station increases. It will increase. In addition, since electro-optic conversion and optical fiber transmission are added to the antenna end and the signal processing unit, it is necessary to perform signal processing in consideration of transmission delay, and further time constraints are added to real-time signal processing. It becomes. In addition, since the radio system is changed at the centralized control station in a lump, there is a problem that a mobile station that has been communicating with the radio system before the change cannot communicate thereafter.

  The present invention has been made in view of such a situation, and an object of the present invention is to reduce the processing load on the central control station and to change the radio system without disconnecting the mobile station in communication. Is to provide.

  In order to solve the above-described problems, the present invention provides a radio base station that performs radio communication with a mobile station that can change a radio system, and a radio communication unit that can change the radio system (for example, communication in this embodiment) Unit 21), a change request receiving means for receiving a radio system change request from the mobile station (for example, radio system change request receiving unit 24 in the present embodiment), and whether or not the radio system can be changed according to the change request. A wireless base station comprising a wireless system control means for determining (for example, a wireless system changing unit 22 in the present embodiment).

  The present invention is a radio base station that performs radio communication with a mobile station capable of changing a radio system, and a radio communication unit capable of changing the radio system (for example, the radio system change request receiving unit 54 in the present embodiment) A change request transfer means (for example, the wireless method change request receiving unit 54 and the wireless method change request transmitting unit 59 in the present embodiment) for transferring the wireless method change request received from the mobile station to the centralized control station; Change request receiving means for receiving a wireless system change request from a station (for example, wireless system change request receiving unit 54 in the present embodiment), and wireless system control means for determining whether or not to change the wireless system in response to the change request (For example, a radio system changing unit 52 in the present embodiment).

  The radio base station according to claim 1 or 2, wherein the radio system control means determines that the change is possible when there is no mobile station connected to the own station.

  The present invention further includes a connection change request means for transmitting a connection change request to another radio base station to the mobile station connected to the own station and obtaining a reply as to whether or not to change the connection from the mobile station, The wireless system control means represents that the connection change request means (for example, the connection change request unit 26 and the connection change request unit 56 in the present embodiment) performs connection change from all of the mobile stations connected to the own station. The wireless base station according to claim 1, further comprising determining that the change is possible when the connection change notification is obtained.

  The present invention further comprises storage means for storing wireless system history information, and the wireless system control means changes the wireless system based on the history information when there is no mobile station connected to the local station. The wireless base station according to any one of claims 1 to 4, further characterized.

  The present invention is a centralized control station that controls a plurality of radio base stations whose radio system can be changed, and that receives a radio system change request from a mobile station (for example, the communication unit 31 in this embodiment). ), In response to the change request, a radio base station determination unit (for example, the radio base station determination unit 32 in the present embodiment) that determines a radio base station that can be changed to the radio system requested to be changed, and a determination result A centralized control station comprising change request means (for example, a radio system change request transmission unit 33 in the present embodiment) that transmits a radio system change request to a radio base station.

  The present invention further comprises list receiving means for acquiring a list of wireless base stations connectable to the mobile station via the base station, and the wireless base station determining means is a wireless base station that can be changed to a wireless system based on the list. The central control station according to claim 6, further comprising:

  The present invention is a mobile station capable of changing a radio system for communicating with a radio base station, and a change request transmitting means for transmitting a radio system change request to the radio base station (for example, a radio system change in this embodiment) Request transmission unit 14, wireless system change request transmission unit 44) and wireless system control means for changing the wireless system requested to be changed after transmitting the change request (for example, wireless system change unit 15 in the present embodiment, wireless And a system change unit 45).

  The present invention provides a list generating means for generating a list of radio base stations connectable to the own station (for example, the accessible station list generating unit 46 in the present embodiment), and a list transmitting means for transmitting the list to the base station ( For example, the mobile station according to claim 8, further comprising a communication unit 41) in the present embodiment.

  The present invention provides a change request receiving means (for example, the communication unit 41 in the present embodiment) that receives a connection change request from a first radio base station that is connected to the own station, and a connectable second radio base station A wireless communication means (for example, the communication unit 41 in the present embodiment) that transmits a connection change notification to the first wireless base station and changes the connection destination to the second wireless base station. The mobile station according to claim 8, further comprising a mobile station.

  As described above, according to the present invention, each radio base station performs control related to the change of the radio system, and when changing the radio system, the radio base station detects the presence of a mobile station connected to itself. Detecting and changing the wireless system based on the detection result, the load is not concentrated on the central control station, and communication is disconnected even when there is a mobile station in communication The radio system can be changed without any change.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a conceptual diagram of a wireless communication system according to the present embodiment. The wireless communication system according to the first embodiment includes a mobile station 10 and a wireless base station 20. In the radio communication system according to the second embodiment, the central control station 30 in addition to the mobile station 40 having the same configuration as the mobile station 10 and the radio base station 50 having the same configuration as the radio base station 20. It has.

The mobile station 10 can be connected to the network via the radio base station 20. The radio base station 20 has a function of providing radio access to the mobile station 10 and changing the radio system to be provided in response to a request from the mobile station 10. Therefore, each radio base station may introduce a required radio system as appropriate, and it is not necessary to introduce a large number of radio systems in advance. In addition, even when a request for a new wireless system occurs in the future, it is sufficient to introduce the wireless system each time, and the system itself can be operated for a long time.
The centralized control station 30 according to the second embodiment has a function of processing a radio system change request from the mobile station 40 received via the radio base station 50 and instructing the subordinate radio base station 50 to change the radio system. .

  Examples of the wireless system include a wireless LAN system and a mobile communication system. Examples of the wireless LAN system include IEEE (Institute of Electrical and Electronic Engineers) standards “IEEE802.11j”, “IEEE802.11b”, “IEEE802.11g”, and the like. Examples of the mobile communication system include a radio access method called “Mobile WiMAX” compliant with “IEEE802.16e”, a CDMA method called “CDMA2000 lxEV-DO”, and the like. In “CDMA2000 lxEV-DO”, EV means Evolution and DO means Data only.

Hereinafter, as a first embodiment, a wireless communication system based on a distributed control method in which the wireless base station 20 autonomously determines a change of a wireless method will be described, and later, from a centralized control station 30 as a second embodiment. A wireless communication system based on a centralized control method in which the wireless base station 50 changes the wireless method according to the instruction will be described.
In addition, when the wireless method is changed in the description of the present embodiment, the wireless method before the change is referred to as an old wireless method, and the wireless method after the change is referred to as a new wireless method.

<First Embodiment: Distributed Control Method>
As a first embodiment, a wireless communication system using a distributed control system according to the present invention will be described.
FIG. 2 is a block diagram showing the configuration of the mobile station 10 according to the present embodiment.
The mobile station 10 is a wireless terminal such as a mobile phone terminal, and includes a communication unit 11, a radio wave detection unit 12, a connection unit 13, a wireless method change request transmission unit 14, and a wireless method change unit 15. .

The communication unit 11 is, for example, a functional unit that performs radio communication with the radio base station 20, and in this embodiment, the radio scheme can be changed by software radio technology. However, it is not always necessary to use the software radio technology, and if the radio system can be changed, the radio system may be changed by, for example, providing a plurality of types of radio circuits and switching the use.
The radio wave detection unit 12 is a functional unit that detects radio waves. For example, when changing the radio system, the radio wave detection unit 12 detects radio waves of a new radio system.
The connection unit 13 makes a connection request to the radio base station 20 by the new radio system.

The radio system change request transmission unit 14 transmits a radio system change request for requesting provision of a new radio system service to the radio base station 20. The radio system changing unit 15 changes the radio system of the communication unit 11.
FIG. 3 is a block diagram showing the configuration of the radio base station 20 according to the present embodiment.
The radio base station 20 performs radio communication with the mobile station 10, a communication unit 21, a radio system change unit 22, a radio system change availability determination unit 23, a radio system change request reception unit 24, and a mobile station detection unit 25. And a connection change request unit 26, a radio system change history storage unit 27, and a time division radio system change unit 28.

  The communication unit 21 is, for example, a functional unit that performs wireless communication with the mobile station 10. In this embodiment, the wireless method can be changed by software wireless technology. However, the embodiment is not limited thereto, and a plurality of wireless communication schemes may be provided. The radio system changing unit 22 changes the radio system of the communication unit 11. The radio system change availability determination unit 23 is a functional unit that determines whether or not to change the radio system provided by the radio base station 20. The radio system change request receiving unit 24 receives a radio system change request transmitted from the mobile station 10. The mobile station detection unit 25 is a functional unit that detects a mobile station connected to itself.

  Then, the connection change request unit 26 transmits a connection destination change request to the mobile station 10 connected thereto. The radio system change history storage unit 27 stores, for example, the number of times a radio system change request has been received from the mobile station 10 and history information on the change of the radio system. Based on the information stored in the radio system change history storage unit 27, the time division radio system change unit 28 stores the radio system change history when there is no terminal connected to the radio base station 20 and is in a standby state. Based on the history information stored in the unit 27, the wireless system is autonomously switched to wait for a connection from the mobile station 10.

  Next, an operation example of the wireless communication system using the distributed control system according to the present embodiment will be described. In the distributed control, the radio base station 20 that has received the radio scheme change request from the mobile station 10 performs autonomous radio scheme change processing. For this reason, the cost of separately laying a centralized control station or the like is unnecessary, and it is possible to quickly respond to a request for changing the radio system.

  FIG. 4 shows a processing flowchart of the mobile station 10 during distributed control. In this flowchart, the process from the time when a request for another radio system is generated in the mobile station 10 (step S101) until the connection request is made to the radio base station 20 by the actually requested radio system (step S102). Show. In the figure, the process given the star is a process performed by the requested wireless system, and the mark is a process performed by the current wireless system.

  When the mobile station 10 starts the wireless system change request process, first, the radio wave detection unit 12 detects whether or not a new wireless system is provided in the vicinity (step S103). When the radio wave detection unit 12 detects a radio wave based on the new radio system (step S104), the connection unit 13 transmits a connection request to the radio base station 20 that provides the new radio system (step S102). On the other hand, when the radio wave detection unit 12 cannot detect radio waves by the new radio system (step S105), the radio system change request transmission unit 14 transmits a radio system change request to the radio base station 20 (step S105). S106).

  Here, when there are a plurality of communicable radio base stations 20, the radio system change request transmission unit 14 receives the radio base station 20 that transmits the radio system change request from each radio base station 20. You may select based on electric power. Further, the radio system change request transmission unit 14 stores, for example, identification information of the radio base station 20 that makes a radio system change request in advance, and the radio base station 20 may be a radio system change request destination. You may select based on resource information.

  After the wireless method change request transmission unit 14 transmits the wireless method change request, the wireless method change unit 15 changes the communication unit 11 to the new wireless method and enters a standby state (step S107). When the radio wave detection unit 12 detects a radio wave of a new radio system (step S108), a connection request is executed (step S102). In addition, when the time-out occurs after a predetermined time without being detected (step S109), the radio base station 20 that performs the radio system change request again is selected and the radio system change request is executed. (Step S106). Each unit included in the mobile station 10 repeats the processing from step S106 to step S107, for example, a predetermined number of times, and if the radio wave is not detected, the radio system changing unit 15 changes the communication unit 11 to the old radio system again. To do.

  Next, the operation of the radio base station 20 is shown. FIG. 5 shows a processing flow of the radio base station 20 until a radio system change request is received from the mobile station 10 (step S201) and the request is completed (step S202) or discarded (step S203). It is a flowchart. In the figure, the process given the star is a process performed by the requested wireless system, and the mark is a process performed by the current wireless system. The radio base station 20 to which no connected mobile station 10 exists statistically processes the history of the radio system provided so far, and periodically switches the radio system based on the result, from the mobile station 10 It is also possible to wait for a connection. Such a switching process will be described later.

  The radio system change request receiving unit 24 receives a radio system change request from the mobile station 10 (step S201). The radio system changing unit 22 stores in advance list information of radio systems that can be provided by the own device based on processing capability, and determines whether the requested radio system is a radio system that can be provided by the local station. Determination is made (step S204). If it cannot be provided due to insufficient processing capacity (step S205), the wireless system change unit 22 discards the wireless system change request (step S203). If there is no problem with the processing capability, the mobile station detection unit 25 checks the number of other mobile stations connected to the radio base station 20 (step S206).

  If no other mobile station 10 is connected (step S207), the radio system changing unit 22 changes the communication unit 21 to the new radio system and enters a standby state (step S208). If there is another mobile station 10 connected to the own station (step S210), for example, the connection change request unit 26 changes the connection to the other radio base station 20 with respect to the mobile station 10. A request is transmitted (step S211). When there is a mobile station that cannot be switched (step S213), the radio system change availability determination unit 23 discards the radio system change request (step S203). If the communication unit 21 receives a connection change notification indicating that switching is possible from all the mobile stations 10 (step S212), the wireless method changing unit 22 changes the communication unit 11 to the new wireless method and is in a standby state. (Step S208). When the communication unit 21 receives a connection request from the mobile station 10 (step S214), the connection with the mobile station 10 is established (step S202). When a predetermined time has passed without receiving a connection request (step S209), the wireless system change permission determination unit 23 discards the wireless system change request (step S203), and the wireless system change unit 22 Changes the communication unit 21 to the old radio system.

  Here, when the radio base station 20 has the capability of providing a plurality of radio systems, the same processing is performed, for example, providing the requested radio system while maintaining one of the radio systems. Etc. are possible.

Next, an operation example in which the mobile station 10 and the radio base station 20 perform information communication and change the radio system will be described. FIG. 6 shows an operation example until the connection is established after the radio system is changed, taking the mobile station SS1, the radio base station BS1, and the radio base station BS2 according to the present embodiment as an example.
First, when a request for another radio system is generated in the mobile station SS1, the mobile station SS1 selects one from communicable radio base stations and transmits a radio system change request (step S100). In FIG. 6, the mobile station SS1 first transmits a radio system change request to the radio base station BS1 (step S101). After receiving this request, the radio base station BS1 determines whether or not the radio system can be changed through the availability of the capability to be provided or the negotiation with other connected mobile stations (step S211_1). In the example of FIG. 6, for example, the wireless system change request is discarded as it cannot be provided because there is a mobile station that cannot switch the connection destination, for example (step S203).

  After transmitting the radio system change request, the mobile station SS1 is in a standby state in the destination radio system (step S107), but there is no response from the requested radio base station BS1 due to a timeout (step S109). Is detected. Even if the requested radio base station switches the radio system, even if the mobile station SS1 cannot receive radio waves due to a change in cell size, it can be detected by this timeout process. Thereafter, the requesting radio base station is selected again (step S100_2), and a radio scheme provision request is transmitted (step S101_2).

  In the example of FIG. 6, it is assumed that the radio base station BS2 is selected as the next radio system change request destination. The radio base station BS2 accepts this request (step S211_2), enters a standby state with the requested radio system, and notifies the mobile station SS1 of the change of the communication system (step S208). Since the mobile station SS1 is already in the standby state, the radio wave detection unit 12 transmits a connection request immediately after detecting the radio wave (step S102) and establishes a connection (step S202).

<Standby for radio base station>
The radio base station 20 may be configured to provide a plurality of radio systems in a time division manner when there is no mobile station 10 that performs communication via itself. With reference to FIG. 13, an operation example of time division radio system change control will be described.
The radio base station 20 is an example in which the radio system used in the standby state is switched in a time division manner based on the provision history of the radio system so far. The time division radio system changing unit 28 stores the time when the radio system is changed, and measures the time from the start of provision of the old radio system to the introduction of the new radio system when changing the radio. .

  For example, it is assumed that the radio base station 20 has provided the radio scheme A at 60%, the radio scheme B at 30%, and the radio scheme C at a rate of 10% so far. The provision history here may be the actual time during which each wireless method has been provided, or the number of mobile stations 10 that have requested each wireless method so far. Using the provision history, the radio base station 20 determines a provision ratio of time to each radio system. In the example of FIG. 8, the unit time T is assigned 0.6T to the wireless system A, 0.3T to the wireless system B, and 0.1T to the wireless system C according to the provision ratio, and enters a standby state while switching between them. . When a connection request from the mobile station 10 is received, the wireless system at the time when the connection request is made is fixed. For example, in FIG. 8, since the connection request is received when waiting in the wireless system A, wireless access is provided by the wireless system A thereafter.

<Second Embodiment: Centralized Control Method>
As a second embodiment, a centralized control type wireless communication system according to the present invention will be described. In the centralized control, in addition to the mobile station 40 and the radio base station 50, a centralized control station 30 that controls the radio communication schemes of the plurality of radio base stations 50 is installed. The centralized control station 30 has a queue (radio system change request storage unit 34) that holds a radio system change request from the mobile station 40, and sequentially processes the radio system change requests in the queue. Therefore, it is possible to provide a wireless system that is consistent throughout the entire area while preventing a situation in which a plurality of wireless base stations 50 change the wireless system at one time.

FIG. 7 is a block diagram showing the configuration of the mobile station 40 according to the present embodiment.
The mobile station according to the present embodiment has the same configuration as that of the first embodiment, and the description of the same configuration and processing is omitted. Hereinafter, the configuration and processing unique to the second embodiment will be described.
The mobile station 40 according to the second embodiment has an accessible station list generation unit 46. The accessible station list generation unit 46 detects connectable radio base stations 50 and generates information that lists the identification information.

FIG. 8 is a block diagram showing a configuration of the radio base station 50 according to the present embodiment.
The radio base station 50 according to the present embodiment has the same configuration as that of the first embodiment, the description of the same configuration and processing is omitted, and the configuration and processing unique to the second embodiment will be described below. To do.
The radio base station 50 includes a radio system change request transmission unit 59. The radio system change request transmission unit 59 transfers the radio system change request received from the mobile station 40 to the central control station 30.

FIG. 9 is a block diagram showing a configuration of the centralized control station 30 according to the present embodiment.
The centralized control station 30 controls the radio systems of the plurality of radio base stations 50 via the network, and communicates 31, a radio base station determination unit 32, a radio system change request transmission unit 33, and a radio system change request storage. Part 34.
The communication unit 31 receives a radio system change request transmitted from the mobile station 40 via the radio base station 50. The radio base station determination unit 32 refers to a correspondence table in which the radio base station 50 and the radio schemes that can be provided are associated with each other in response to the radio scheme change request, and provides the radio scheme. The identification information of the radio base station 50 is detected. The radio system change request transmission unit 33 transmits a radio system change command to the radio base station 50 corresponding to the identification information detected by the radio base station determination unit 32. The wireless system change request storage unit 34 stores received wireless system change requests as a queue.

FIG. 10 shows a process flowchart of the mobile station 40 during the centralized control. This flowchart shows a flow from the time when the mobile station 40 makes a request for another radio system (step S301) to the time when the mobile station transmits a radio wave detection report to the centralized control station 30 (step S302). Yes.
The radio wave detection unit 42 of the mobile station 40 that has generated a request for the new radio system first searches for whether the new radio system is provided in the vicinity (step S303). When the radio wave detection unit 42 can detect the new radio system (step S304), the connection unit 43 makes a connection request to the radio base station 50 that provides the radio system (step S302). On the other hand, when it cannot detect (step S305), the radio system change request transmission unit 44 transmits a radio system change request to the central control station 30 via the radio base station 50 (step S306).

  In the case of centralized control, the accessible station list generation unit 46 creates a list of identification information of radio base stations that can receive radio waves in the old radio system (hereinafter referred to as accessible station list), and requests a radio system change request. Send at the same time. After the radio system change request transmission unit 44 transmits the radio system change request and the accessible station list to the centralized control station 30, the radio system change unit 45 changes the communication unit 41 to the new radio system, and the mobile station 40 enters a standby state. Enter (step S307). When the radio wave detection unit 42 detects a radio wave of a new radio system (step S308), the connection unit 43 performs connection processing and notifies the central control station 30 that the radio wave has been detected (step S302). If the time-out occurs due to no detection (step S309), the wireless system change request and the accessible station list are transmitted again (step S306).

  The radio base station 50 plays a role of relaying a radio system change request from the mobile station 40 to the central control station 30 during centralized control. Further, when a wireless system change request is received from the centralized control station 30, the wireless system changing process is executed according to the flowchart shown in FIG. In the centralized control, the central control station 30 is notified of the fact that the wireless system change request is discarded (S203 in FIG. 5).

  A processing flowchart of the central control station 30 is shown in FIG. This flowchart shows a flow from the time when the central control station 30 receives a radio system change request from the mobile station 40 (step S401) to the completion of processing of all radio system change requests in the queue (step S402). ing.

  When the communication unit 31 of the centralized control station 30 receives the radio system change request and the accessible station list, the radio base station determination unit 32 selects the radio base station 50 from the accessible station list and transmits the radio system change request. (Step S403). Here, the selection of the radio base station that is the radio system change request destination by the radio base station determination unit 32 may be based on the radio wave reception power at the requesting mobile station of each radio base station, or based on other resource information Also good. The central control station enters a standby state after transmitting the wireless system change request (step S404).

  After that, when the communication unit 31 receives the notification of discarding the wireless system change request or when a predetermined time has elapsed (step S405), the wireless base station determination unit 32 again performs wireless communication from the accessible station list. One base station is selected and a radio system change request is issued (step S403). When receiving the radio wave detection report from the mobile station 40 (step S406), the radio base station determination unit 32 completes the processing of the radio system change request and deletes the corresponding radio system change request from the queue. Here, the radio system change request to be deleted is not necessarily the first radio system change request in the queue. The queue for the wireless system change request is confirmed with reference to the wireless system change request storage unit 34 (step S407). If there is a radio system change request to be processed (step S408), a radio base station that should actually provide the radio system is selected from the accessible station list received simultaneously with the request, and a radio system change request is issued. Transmit (step S403). When there is no request already in the queue (step S409), the radio base station determination unit 32 completes the radio system change request processing (step S402).

Next, an operation example in which the mobile station 40, the radio base station 50, and the central control station 30 perform information communication and change the radio system will be described. FIG. 12 is an operation example until the connection is established after the wireless system is changed.
In FIG. 12, two mobile stations (mobile station SS10 and mobile station SS20) are connected to radio base station BS100 and radio base station BS200, respectively. The radio base station BS100 and the radio base station BS200 are connected to a centralized control station (hereinafter referred to as CM) by wire, and are centrally controlled by the CM.

  First, a request for switching the radio system is generated in the mobile station SS10 (step S300_1), and transmitted to the CM via the radio base station BS10 (step S306_2, step S501) together with the accessible station list (step S505). After receiving the radio system change request and the accessible station list, the CM selects a radio base station whose radio system should be switched from the accessible station list (step S403_1), and transmits the radio system change request to the selected radio base station ( Step S404_1). Here, for selection of a radio base station as a radio system change request destination, radio wave reception power from each radio base station in the request source mobile station may be used, or resource information of each radio base station may be used. .

  In the example of FIG. 7, a radio system change request is first issued to the radio base station BS10. The radio base station BS10 that has received the command investigates whether or not the commanded radio system can be provided (step S502). Since the radio system requested this time cannot be provided, a message indicating that the radio system cannot be provided is sent to the CM. (Step S504).

The CM that has received the message that the radio system cannot be provided selects the radio base station BS20 as another radio base station (step S403_2) and issues a command (step S404_2). Since the radio base station BS20 that has received the command can switch to the radio system, the radio base station BS20 starts to provide radio access by switching the radio system (step S503). The mobile station SS10 detects these radio waves (step S308_1), makes a connection request to the radio base station BS20 (step S302_1), and the radio base station BS20 responds (step S310_1). Then, the mobile station SS10 transmits a radio system change completion notification to the CM via the radio base station BS20 (step S311_1, step S312_1),
Communication is established (step S313_1).

  Further, it is assumed that the mobile station SS20 has transmitted to the CM a request to change to the same wireless system as the mobile station SS10 (step S300_2, step S306_2, step S501_2, step S505_2). In the example of FIG. 12, when the CM receives a radio system change request from the mobile station SS20, the CM is processing a radio system change request from the mobile station BS10, so the radio system change request received from the mobile station SS20 is queued. It is stored in (wireless method change request storage unit 34) (step S410).

  In addition, since the mobile station SS20 has started waiting for the new scheme when the radio scheme change request is transmitted in step S300_2, when the radio base station BS20 starts providing the new scheme in step S503, The mobile station SS20 detects the new radio wave (step S308_2). Thereafter, similarly to the mobile station SS10, connection establishment with the radio base station BS20 is performed (step S302_2, step S310_2, step S310_2, step S311_2, step S312_2, step S313_2). Further, when the CM receives the wireless method request completion notification, the CM deletes the wireless method request from the queue (steps S411 and S411_2).

  In the above-described embodiment, a case where only one communication system can be provided for each of the mobile station and the radio base station is described. However, a plurality of communication systems may be provided at the same time. It is possible to construct an adaptive service area.

  The program for realizing the function of the processing unit in the present invention is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into the computer system and executed to change the wireless system. May be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a storage device such as a hard disk built in the computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

1 is a diagram illustrating a wireless communication system according to an embodiment of the present invention. 1 is a block diagram illustrating a mobile station according to a first embodiment of the present invention. 1 is a block diagram illustrating a radio base station according to a first embodiment of the present invention. 3 is a flowchart illustrating an operation example of the mobile station according to the first embodiment of the present invention. 3 is a flowchart illustrating an operation example of the mobile station according to the first embodiment of the present invention. It is a figure which shows the operation example of the radio system change by the 1st Embodiment of this invention. It is a block diagram which shows the mobile station by the 2nd Embodiment of this invention. It is a block diagram which shows the radio base station by the 2nd Embodiment of this invention. It is a block diagram which shows the centralized control station by the 2nd Embodiment of this invention. 7 is a flowchart illustrating an operation example of a mobile station according to the second embodiment of the present invention. It is a flowchart which shows the operation example of the centralized control station by the 2nd Embodiment of this invention. It is a figure which shows the operation example of the radio | wireless system change by the 2nd Embodiment of this invention. It is a figure which shows the operation example of the radio system change by the time division by the 1st Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Mobile station 11 Communication part 12 Radio wave detection part 13 Connection part 14 Radio system change request transmission part 15 Radio system change part 20 Radio base station 21 Communication part 22 Radio system change part 23 Radio system change availability determination part 24 Radio system change request reception Unit 25 mobile station detection unit 26 connection change request unit 27 radio system change history storage unit 28 time division radio system change unit 30 centralized control station 31 communication unit 32 radio base station determination unit 33 radio system change request transmission unit 34 radio system change request Storage unit 40 Mobile station 41 Communication unit 42 Radio wave detection unit 43 Connection unit 44 Radio system change request transmission unit 45 Radio system change unit 46 Accessible station list generation unit 50 Radio base station 51 Communication unit 52 Radio system change unit 53 Radio system change Permission determination unit 54 Wireless system change request receiving unit 55 Mobile station detection unit 56 Connection change request unit 57 Wireless system At further history storage unit 58 divided radio mode change unit 59 radio system change request transmission unit

Claims (10)

A wireless base station that performs wireless communication with a mobile station capable of changing a wireless method,
A wireless communication means capable of changing the wireless system;
Change request receiving means for receiving a wireless system change request from a mobile station;
In response to the change request, a wireless system control means for determining whether or not the wireless system can be changed,
A radio base station comprising: A wireless base station that performs wireless communication with a mobile station capable of changing a wireless method,
A wireless communication means capable of changing the wireless system;
Change request transfer means for transferring a wireless system change request received from a mobile station to a centralized control station;
Change request receiving means for receiving a wireless system change request from the centralized control station;
In response to the change request, a wireless system control means for determining whether or not the wireless system can be changed,
A radio base station comprising: The radio base station according to claim 1 or 2, wherein the radio system control means determines that the change is possible when there is no mobile station connected to the own station. A connection change request means for transmitting a connection change request to another radio base station to the mobile station connected to the own station and obtaining a reply as to whether or not to change the connection from the mobile station is further provided,
The wireless method control means determines that the change is possible when the connection change request means obtains a connection change notification indicating that the connection change is performed from all of the mobile stations connected to the own station. The radio base station according to claim 1 or 2. It further comprises storage means for storing wireless history information,
5. The radio system control means according to claim 1, further comprising: changing a radio system based on the history information when there is no mobile station connected to the local station. 6. Wireless base station. A centralized control station that controls a plurality of radio base stations whose radio system can be changed,
A communication unit that receives a wireless system change request from a mobile station;
In response to the change request, a radio base station determination unit that determines a radio base station that can be changed to the radio system requested to be changed,
Change request means for transmitting a wireless system change request to the wireless base station of the determination result;
A centralized control station comprising: A list receiving means for acquiring a list of wireless base stations connectable to the mobile station via the base station;
The central control station according to claim 6, wherein the radio base station determination unit determines a radio base station that can be changed to the radio system based on the list. A mobile station capable of changing a radio system for communicating with a radio base station,
Change request transmitting means for transmitting a wireless system change request to a wireless base station;
After transmitting the change request, a wireless system control means for changing the wireless system requested to be changed,
A mobile station comprising: List generating means for generating a list of wireless base stations connectable to the own station;
The mobile station according to claim 8, further comprising: a list transmission unit that transmits the list to a base station. Change request receiving means for receiving a connection change request from the first radio base station connected to the own station;
Wireless communication means for transmitting a connection change notification to the first radio base station and changing the connection destination to the second radio base station when a connectable second radio base station is detected; and The mobile station according to claim 8 or 9, wherein the mobile station is characterized.

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