JP2013121116A - Private wireless telephone system having power saving function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for suppressing power consumption in wireless base stations and a private wireless telephone system.SOLUTION: A private wireless telephone system has wireless base stations which perform wireless transmission and reception with wireless terminals. The private wireless telephone system manages communication states between the wireless terminals and the wireless base stations, instructs the communicating wireless terminals to shift the wireless base stations to be connected, and optimizes a communication environment of the wireless terminals and the wireless base stations to create a wireless base station which is not used for communication. Then, the system performs power saving by stopping wireless transmission and reception of the wireless base station which is not used for communication.

Description

  The present invention relates to a power saving technique of a private wireless telephone system that accommodates a plurality of wireless terminals, and more particularly to a private wireless telephone system in which a plurality of PHS (Personal Handy-phone System) wireless base stations that cover the same cell area exist. It relates to power saving technology.

  In a conventional wireless telephone system, a technique for reducing power consumption mainly on the wireless terminal side is well known. For example, as a technique for reducing the power consumption on the wireless terminal side, there is a technique for reducing the power consumption by extending the transmission interval from the wireless terminal and reducing the number of times of power use for wireless transmission.

  On the other hand, as a technique for reducing power consumption on the radio base station side, there is a technique as described in Patent Document 1. In Patent Literature 1, a wireless base station acquires a transition of a wireless terminal out of service, or a transition of a wireless terminal to another wireless base station by each means, so that the wireless terminal is in a cell area configured by the wireless base station. A technique for reducing power consumption by stopping transmission / reception of a radio base station when it is determined that it does not exist is disclosed.

JP 2010-268230 A

  However, when a plurality of wireless base stations are connected to a private branch exchange as in a private wireless telephone system, there is a case where it is not possible to efficiently save power if this technique is applied.

  Specifically, a local PHS system in which a PHS terminal is applied as a local radio telephone terminal for a company is well known. In this local PHS system, a radio base station having a maximum of three communication slots is used. When two or more units are connected and one communication slot of each radio base station is in use, each radio base station performs radio transmission / reception of the radio base station even though there are surplus communication slots. There is a problem that it cannot be stopped.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to integrate communication slots to be used in one radio base station when there are a plurality of radio base stations in the same cell area, Another object of the present invention is to provide a technology for a private wireless telephone system that stops power transmission and reception by stopping wireless transmission / reception of the other wireless base station and efficiently saves power.

  In order to solve the above problems, the present invention provides a private wireless telephone system comprising a plurality of wireless terminals, a plurality of wireless base stations that accommodate the plurality of wireless terminals, and a private branch exchange that accommodates the plurality of wireless base stations. The private branch exchange includes a call monitoring means for monitoring the number of calls relayed by each of the radio base stations, and a radio for specifying a radio base station whose number of calls being relayed is less than K (K <N). A base station specifying means, a wireless terminal specifying means for specifying a wireless terminal making a call through the specified wireless base station, and a wireless terminal making a call through a predetermined wireless base other than the wireless base A wireless base station having handover means for executing handover to the wireless base station and wireless base station power supply stopping means for stopping power supply to a predetermined wireless base station, wherein the number of relayed calls is less than K Have a call through A wireless terminal is identified, a handover is performed to a wireless base station other than the wireless base station that relays the wireless terminal and the number of relayed calls is K or more, and the call of the identified wireless terminal is relayed When the power supply to the wireless base station that has been stopped is stopped, and each of the plurality of wireless terminals is instructed to execute a handover from the private branch exchange, any one of the plurality of wireless base stations designated by the private branch exchange It is characterized in that a handover to is performed.

  According to the present invention, a wireless base station that is not used for communication performs optimization of the wireless terminal and the wireless base station by instructing the wireless base station to which the wireless terminal in communication belongs to the local wireless telephone system. Can efficiently stop radio transmission / reception of the radio base station to save power.

  Moreover, if the wireless terminal side is a terminal based on RCR STD-28 (Radio Industry Association Standard), no special control or device is required.

FIG. 1 is a diagram showing an overall configuration of a local radio telephone system using a local PHS terminal according to an embodiment of the present invention. FIG. 2 is a schematic functional block diagram of the radio base station shown in FIG. FIG. 3 is a schematic functional block diagram of the PBX shown in FIG. FIG. 4 is a schematic diagram of a base station-specific communication terminal control table according to an embodiment of the present invention. FIG. 5 is a sequence diagram for explaining operations of “until transmission / reception is stopped at the radio base station” and “until transmission / reception is resumed at the radio base station” according to an embodiment of the present invention. FIG. 6 is a flowchart for explaining the operation of the radio base station. FIG. 7 is a flowchart for explaining the operation of the PBX.

  Embodiments of the present invention will be described below.

  FIG. 1 is a diagram showing an overall configuration of a local radio telephone system using a local PHS terminal according to an embodiment of the present invention.

  As shown in the figure, a local radio telephone system according to the present embodiment includes a plurality of local PHS terminals 1-m (in this embodiment, m = 1, 2, 3, 4) and a plurality of radio base stations 2. -N (n = 1, 2 in this embodiment) and a PBX 3 that connects a plurality of wireless base stations and a network 4 such as a public network.

  The local PHS terminal 1-m has a radio control function based on RCR STD-28 (Radio Industry Association Standard), a function for performing call control, and a man-machine interface function as a telephone.

  The radio base station 2-n is connected to the PBX 3 and has three independent slots for communication, and each slot uses three local PHSs simultaneously in one radio base station 2-n. Wireless communication can be set up with the terminal 1-m. Note that the radio base station 2-n has a function along the RCR STD-28 responsible for radio communication control with the radio PHS terminal 1-m. In addition, the installation locations of the radio base station 2-1 and the radio base station 2-2 in the present embodiment are installed at extremely close positions, and the communication range between the radio base station 2-1 and the radio base station 2-2. Are the same.

  The PBX 3 has a circuit switching function with the network 4 such as a public network, and manages a plurality of wireless PHS terminals 1-m and a plurality of wireless base stations 2-n for outgoing and incoming call control.

  FIG. 2 is a schematic functional block diagram of the radio base station shown in FIG.

  The configuration in FIG. 2 is an example, and any configuration is applicable as long as it functions as the radio base station 2-n.

  The radio base station 2-n shown in FIG. 2 includes an antenna unit 20, a radio transmission unit 21, a radio reception unit 22, a PBX command control unit 23, a PBX interface unit 24, a clock unit 25, and a power control unit. 26 and a control unit 27.

  The antenna unit 20 serves as an interface with the local PHS terminal 1-m, receives a transmission message from the wireless transmission unit 21, and transmits it to the local PHS terminal 1-m. In addition, the antenna unit 20 sends a reception message from the local PHS terminal 1 -m to the wireless reception unit 22.

  The wireless transmission unit 21 transmits a message from the antenna unit 20 to the local PHS terminal 1-m using the carrier designated by the control unit 27 in accordance with an instruction from the control unit 27.

  The radio reception unit 22 receives a message transmitted from the local PHS terminal 1-m from the antenna unit 20 using the carrier specified by the control unit 27 in accordance with an instruction from the control unit 27, and sends the received message to the control unit 27. hand over.

  The PBX command control unit 23 generates a command to be transmitted to the PBX 3 in response to an instruction from the control unit 27, transmits the command to the PBX interface unit 24, and the PBX command control unit 23 passes through the PBX interface unit 24. When the message from the PBX 3 is received, the message is sent to the control unit 27.

  The PBX interface unit 24 sends a message from the PBX command control unit 23 to the PBX 3, sends the message received from the PBX 3 to the PBX command control unit 23, and the PBX interface unit 24 sends the synchronization data to the clock unit 25. And sending to the power supply control unit 26 an instruction to stop wireless transmission / reception from the PBX 3 and an instruction to stop wireless transmission / reception.

  The clock unit 25 includes a crystal oscillator and an electronic circuit that corrects the oscillation. The clock unit 25 supplies a clock to the wireless transmission unit 21 and the wireless reception unit 22 to form a wireless transmission / reception timing. In addition, the clock unit 25 operates continuously even when wireless transmission / reception is stopped in order to maintain the accuracy of the clock, and corrects the clock deviation based on the synchronization data from the PBX. As a result, the radio base station 2-n can perform the radio transmission / reception timing again without searching for the radio transmission / reception timing.

  The power supply control unit 26 receives an instruction to stop radio transmission / reception or resume radio transmission / reception from the PBX 3 from the PBX interface unit 24. When the radio transmission / reception is stopped, the radio control unit 21, the radio reception unit 22, the PBX command control unit 23, The power supply to the control unit 27 is stopped. On the other hand, when resuming wireless transmission / reception, the power supply control unit 26 resumes power supply to the wireless control unit 21, the wireless reception unit 22, the PBX command control unit 23, and the control unit 27 to enable wireless transmission / reception.

  The control unit 27 comprehensively controls each unit 21 to 24 of the own radio base station 2-n.

  First, the control unit 27 receives a message from the PBX 3 from the PBX command control unit 23, and the control unit 27 analyzes the message. Further, the control unit 27 receives a message from the local PHS terminal 1-m from the wireless reception unit 22, and the control unit 27 analyzes the message.

  And the control part 27 sends a message to the PBX command control part 23, when transmitting a message to PBX3 from the analysis of the received message. On the other hand, when the control unit 27 sends a message to the local PHS terminal 1-m based on the analysis of the received message, the control unit 27 sends the message to the wireless transmission unit 21.

  FIG. 3 is a schematic functional block diagram of the PBX shown in FIG.

  The configuration in FIG. 3 is an example, and any configuration can be applied as long as it functions as the PBX 3. The PBX 3 illustrated in FIG. 3 includes a call control unit 31, a base station interface unit 32-n (n = 1, 2 in the present embodiment), and a storage unit 33. In this example, a base station interface unit 32-n that matches the number of radio base stations 2-n is provided.

  The call control unit 31 controls communication calls of a plurality of local PHS terminals 1-m, and communicates with the local PHS terminals 1-m and messages via the base station interface 32-n corresponding to the radio base station 2-n. , The call control unit 31 stores the communication relationship between the local PHS terminal 1-m and the radio base station 2-n in the base station-specific communication terminal control table 331, and the call control unit 31 It is possible to receive a command for instructing movement of the radio base station 2-n from the control unit 34 to the local PHS terminal 1-m.

  The base station interface unit 32-n is an interface block that transmits and receives messages to and from the radio base station 2-n. The base station interface unit 32-n includes an interface unit 321 and a base station power supply control unit 322.

  The interface unit 321 performs message transmission / reception with the call control unit 31 and the radio base station 2-n, and transmits synchronization data with the clock unit 25 of the radio base station 2-n.

  The base station power supply control unit 322 is responsible for transmitting an instruction to stop transmission / reception or resume transmission / reception to the radio base station 2-n according to an instruction from the control unit 34, and transmits a transmission / reception stop or transmission / reception restart to the interface unit 321 To the radio base station 2-n.

  Further, the base station interface unit 32-n has a one-to-one relationship with the radio base station 2-n.

  The storage unit 33 is a part that stores management information for a plurality of radio base stations 2-n. The storage unit 33 includes a base station-specific communication terminal control table 331.

  The base station-specific communication terminal control table 331 includes a local PHS terminal 1-m that establishes a communication call to the radio base station 2-n, a radio transmission / reception state of the radio base station 2-n, a radio base station It is a table which memorize | stores the movement destination candidate of the local PHS terminal 1-m in communication between 2-n. FIG. 4 is a schematic diagram of a base station-specific communication terminal control table according to an embodiment of the present invention.

  As shown in the figure, the base station-specific communication terminal control table 331 includes a base station number field 3311, a communicating terminal ID field 3312, an activation state field 3313, and a communicable terminal number field 3314. Information for each radio base station 2-n.

  The base station number field 3311 is a field for storing the numbers of a plurality of radio base stations 2-n that actually exist in the local radio telephone system.

  The in-communication terminal ID field 3312 is a field for storing the number of the local PHS terminal 1-m that has established a communication call using the radio base station 2-n in the base station number field 3311. In this example, since the radio base station 2-n has three independent slots for communication, the number of three local PHS terminals 1-m for each record 3315 is displayed in the communicating terminal ID field 3312. Can be stored.

  The activation state field 3313 is a field for storing the activation state for each radio base station 2-n. The activation state field 3313 indicates that the parameter is “stopped” when wireless transmission / reception is stopped in the corresponding wireless base station 2-n, and the parameter is “active” when wireless transmission / reception is started. Thus, the activation state field 3313 is stored for each radio base station 2-n.

  The number of communicable terminals field 3314 is a field for storing the number of local PHS terminals that can communicate with each radio base station 2-n. The communicable terminal number field 3314 stores a value together with the update of the communicating terminal ID field 3312 in the corresponding radio base station 2-n, but one radio base station 2-n can communicate with up to three. Therefore, if the number of communication local PHS terminals 1-m in the communication terminal ID field 3312 increases, the value of the number of communicable terminals field 3314 is decremented, and the number of communication local PHS terminals 1-m in the communication terminal ID field 3312 decreases. For example, the value of the communicable terminal number field 3314 is incremented and stored for each radio base station 2-n.

  The control unit 34 comprehensively controls each unit 31 to 33 of the PBX 3. Then, using the management information stored in the storage unit 33, the movement instruction of the radio base station 2-n used for communication to the local PHS terminal 1-m and the radio transmission / reception to the radio base station 2-n The stop instruction and the wireless base station 2-n resumption instruction are controlled to be sent to the call control unit 31.

  FIG. 5 is a diagram illustrating an operation sequence until transmission / reception is stopped in a radio base station according to an embodiment of the present invention.

  First, four of the local PHS terminals 1-1 to 1-4 communicate with each other by two of the radio base stations 2-1, 2-2. The local PHS terminals 1-1, 1-2, and 1-3 are communicating with the wireless base station 2-1 using three independent slots, and the local PHS terminals 1-4 are connected to the wireless base station. Communication is being performed using the station 2-2 (S100).

  At this time, the base station-specific communication terminal control table 331 in the storage unit 33 of the PBX 3 indicates that the communication terminal ID 3312 field in the record 3315 of the wireless base station 2-1 is “1-1”, “1-2”, “1”. -3 ”is stored,“ 0 ”is stored in the communicable terminal number field 3314, the communicating terminal ID 3312 field in the record 3315 of the radio base station 2-2 stores“ 1-4 ”, “2” is stored in the number of communicable terminals field 3314, and the activation state field 3313 is both “active”.

  Next, it is assumed that the local PHS terminal 1-1 has disconnected wireless communication with the wireless base station 2-1 (S101). Then, the local PHS terminal 1-1 transmits a call release message from the radio base station 2-1 to the PBX 3 (S102).

  At this time, the control unit 34 of the PBX 3 receives the call release message of the local PHS terminal 1-1 from the radio base station 2-1, and records 3315 of the radio base station 2-1 in the communication terminal control table 331 for each base station. , The local PHS terminal 1-1 is deleted from the communicating terminal ID 3312 field, and the value “1” obtained by incrementing the number of communicable terminals 3314 is stored (S103).

  Then, the control unit 34 is a wireless base station 2-1 and 2-2 that can accommodate terminals, and a communicating terminal ID 3312 in the record 3315 of the wireless base stations 2-1 and 2-2 in the communication terminal control table 331 for each base station In the field, the number of communicating local PHS terminals 1-m is counted, and the number of communication is the same as the number of communicable terminals 3314 in the record 3315 of the other radio base station 2-2, 2-1. It is determined whether only one radio base station 2-n can be activated). In this embodiment, two local PHS terminals 1-2 and 1-3 communicating with the radio base station 2-1 and two communicable terminals 3314 of the radio base station 2-2 are equal in number. The number of communicable terminals 3314 of the wireless base station 2-1 is the same as one in the local PHS terminal 1-4 communicating with the base station 2-2. From this, the control unit 34 determines that the local PHS terminal 1-4 communicating with the wireless base station 2-2 with a small number of communication in the communicating terminal ID 3312 field is transferred to the wireless base station 2-1 (S104). ), And the local PHS terminal that communicates with the radio base station 2-2 can be eliminated.

  Next, the control unit 34 of the PBX 3 sends a TCH switching instruction message to the radio base station 2-2 in order to instruct the local PHS terminal 1-4 to shift the communication to the radio base station 2-1. (S105). The control unit 34 of the PBX 3 creates and transmits a TCH switching instruction message based on the RCR STD-28 specification (designates the radio base station to which to move <in this embodiment, instructs the radio base station 2-1>). To do.

  The control unit 27 of the radio base station 2-2 transmits the received TCH switching instruction message to the terminal 1-4 (S106).

  The control unit 27 of the radio base station 2-1 synchronizes with the local PHS terminal 1-4 by wireless connection (S 107), and when the synchronization is completed, transmits a synchronization completion message to the PBX 3 as a synchronization completion message (S 108). It is assumed that communication with the local PHS terminal 1-4 is in progress (S109).

  As a result, the control unit 34 of the PBX 3 deletes the local PHS terminal 1-4 from the communicating terminal ID 3312 field in the record 3315 of the wireless base station 2-2 of the base station-specific communication terminal control table 331, and the number of communicable terminals 3314 Is stored, and a radio release message is sent to the radio base station 2-2 that has performed communication (S110), and the radio base station 2-2 that has received the radio release message receives the local PHS. A communication slot used for communication with the terminal 1-4 is made empty. When the local PHS terminal 1-4 and the wireless base station 2-1 detect that the local PHS terminal 1-4 and the wireless base station 2-1 are communicating, the control unit 34 of the PBX 3 communicates with the terminal 3331 in communication in the record 3315 of the wireless base station 2-1 in the communication terminal control table 331 by base station. A local PHS terminal 1-4 is added to the field, and a value “0” obtained by decrementing the number of communicable terminals 3314 is stored (S111).

  Then, the control unit 34 of the PBX 3 has no wireless PHS terminal 1-m in communication from the communicating terminal ID field 3312 of the record 3315 of the wireless base station 2-2 in the base station-specific communication terminal control table 331. The activation state field 3313 of the record 3315 of the base station 2-2 is updated to “stopped”, and a transmission / reception stop message is sent to the radio base station 2-2 (S112).

  As a result, the power supply control unit 26 of the radio base station 2-2 stops power supply to the radio transmission unit 21, the radio reception unit 22, the PBX command control unit 23, and the control unit 27 (S113). Thereby, the power of the radio base station 2-2 can be saved.

  Next, it is a figure which shows the operation | movement sequence until transmission / reception is restarted in the radio base station of one Example of this invention.

  First, when the local PHS terminal 1-1 performs wireless connection, the wireless connection to the active wireless base station 2-1 is attempted (S201). However, the control unit 27 of the radio base station 2-1 notifies the PBX 3 of the call setting upon receiving a radio connection from the local PHS terminal 1-1 (S202).

  Then, in the control unit 34 of the PBX 3, the communicable number field 3314 of the base station-specific communication terminal control table 331 of the storage unit 33 is “0” (at this time, the local PHS terminals 1-2, 1-3, 1-4 are By determining that the wireless base station 2-1 cannot communicate (S203), a connection rejection message is sent to the wireless base station 2-1 (S204), and a connection rejection is transmitted to the local PHS terminal. (S205).

  At this time, the control unit 34 of the PBX 3 searches for a nearby radio base station whose activation state 3313 is “stopped” in the base station-specific communication terminal control table 331 (S206), and the radio of the base station-specific communication terminal control table 331 Since the start state field 3313 of the record 3315 of the base station 2-2 is “stopped”, the start state field 3313 of the record 3315 of the radio base station 2-2 of the base station communication terminal control table 331 is set to “start”. The message is updated to “medium”, and a transmission / reception restart message is transmitted to the radio base station 2-2 (S207).

  Thereby, the power supply control unit 26 of the radio base station 2-2 resumes power supply to the radio transmission unit 21, the radio reception unit 22, the PBX command control unit 23, and the control unit 27 (S208). The transmission unit 21 starts wireless transmission at the transmission timing from the clock unit 25, and the wireless reception unit 22 starts wireless reception at the reception timing from the clock unit 25.

  Next, the local PHS terminal 1-1 establishes a wireless connection with the wireless base station 2-2 that has started wireless transmission (S209), and sends a call setting message to the PBX 3 via the wireless base station 2-2 ( S210).

  Then, the control unit 34 of the PBX 3 sets the local PHS terminal 1 to the local PHS terminal 1 in the communication terminal ID field 3312 of the record 3315 of the radio base station 2-2 in the local terminal communication terminal control table 331. -1 is stored, the value "2" decremented from the communicable number field 3314 is stored (S211), and the fact that the call has been secured is transmitted to the radio base station 2-2 by a call setting acceptance message (S212) Then, communication with the local PHS terminal 1-1 can be performed (S213).

  FIG. 6 is a flowchart for explaining the operation of the radio base station 2-n.

  First, the radio base station 2-n receives a message from the PBX 3 and the local PHS terminal 1-m (S300), and determines whether the transmission source is the PBX or the local PHS terminal 1-m (S301).

  When the wireless base station 2-n is a message from the PBX 3 (YES in S301), the power supply control unit 26 determines whether the state of the power supply control unit 26 is wireless transmission / reception stopped (S302), and stops wireless transmission / reception. If it is medium (YES in S302), it is determined whether the received message is a transmission / reception restart message (S303).

  Here, when the received message is not a transmission / reception restart message (NO in S303), the power supply control unit 26 returns to message reception (S300), and when the received message is a transmission / reception restart message (YES in S303), the wireless transmission unit 21 Then, the power supply of the wireless reception unit 22, the PBX command control unit 23, and the control unit 27 is resumed (S304), the state of the power supply control unit 26 is set to the wireless transmission / reception activated state, and wireless transmission / reception is resumed. Return to message reception (S300).

  Further, when the state of the power supply control unit 26 is in a state where wireless transmission / reception is stopped (NO in S302), the radio base station 2-n analyzes another received message by the control unit 27 (S310).

  When the control unit 27 receives a call setting acceptance message (indicating that setting of a call with the local PHS terminal 1-m is permitted by the PBX 3) ("call setting acceptance" in S310), the radio base station 2- The state of the control unit 27 of n is changed to the communication state (S311), and the process returns to message reception (S300).

  When the control unit 27 receives a TCH switching instruction (based on RCR / STD-28> instruction to move the radio base station 2-n that communicates with the local PHS terminal 1-m) (in S310) "TCH switching instruction"), the received TCH switching instruction message is transmitted to the local PHS terminal via the radio transmission unit 21 and the antenna unit 20 (S312), and the state of the radio base station 2-n is TCH switched. Transition to the inside (S313) and return to message reception (S300).

  In addition, when the control unit 27 receives a wireless release message (indicating that the call release with the private PHS terminal 1-m is permitted by the PBX 3) ("wireless release" in S310), the designated private PHS terminal The communication slot used for communication with 1-m is made empty (S314), and the process returns to message reception (S300).

  If the message received by the wireless base station 2-n is a transmission / reception stop message (“transmission / reception stop” in S310), the wireless transmission unit 21, the wireless reception unit 22, the PBX command control unit 23, and the control unit 27, the power supply is stopped (S315), and the process returns to message reception (S300).

  Next, when the radio base station 2-n is a received message from the local PHS terminal and not a received message from the PBX 3 (NO in S301), the control unit 27 analyzes the received message (S320).

  Then, when the received message from the local PHS terminal is a wireless connection (“wireless connection” in S320), the control unit 27 confirms whether the state of the wireless base station 2-n is a TCH switching state (S321). ), In the TCH switching state (YES in S321), a synchronization completion message is transmitted from the control unit 27 to the PBX 3 via the PBX command control unit 23 and the PBX interface unit 24 (S322). If not in the middle state (NO in S321), a call setting message is transmitted from the control unit 27 to the PBX 3 via the PBX command control unit 23 and the PBX interface unit 24 (S323).

  Next, after transmitting a message to the PBX 3 (S322, S323), the control unit 27 assumes that the communication slot corresponding to the local PHS terminal 1-m to communicate with is in use (S324), and changes the state of the radio base station 2-n. The state transits to the communicating state (S325) and returns to message reception (S300).

  On the other hand, if the received message from the local PHS terminal is a wireless disconnection (“wireless disconnection” in S320), the control unit 27 sends a call release message via the PBX command control unit 23 and the PBX interface unit 24. Is transmitted to the PBX 3 (S326), the communication slot corresponding to the local PHS terminal 1-m to communicate is made empty (S327), the state of the radio base station 2-n is changed to the standby state (S328), and the message is received. Return to (S300).

  FIG. 7 is a flowchart for explaining the operation of the PBX.

  First, the control unit 34 of the PBX 3 receives a message from the radio base station 2-n (S400), and performs processing branching based on the received message from the radio base station 2-n (S401).

  Next, when the received message receives a call release from the local PHS terminal 1-m (“call release” in S401), the control unit 34 transmits the message from the radio base station 2 of the communication terminal control table 331 for each base station. The local PHS terminal 1-m that has released the call is deleted from the in-communication terminal ID field 3312 of the -n record 3315, and the base station-specific communication terminal control table 331 is updated with the incremented value in the communicable terminal number field 3314. (S411).

  Then, the control unit 34 determines the number of communicating terminals of the radio base station 2-n that disconnected the local PHS terminal 1-m that has transmitted the call release message from the communicating terminal ID field 3312 of the communication terminal control table 331 for each base station. Reference is made (S412).

  Next, the control unit 34 refers to the number of communicable terminals excluding the local PHS terminal 1-m in communication with the other radio base station 2-n from the communicable number field 3314 of the base station-specific communication terminal control table 331. (S413).

  Here, the control unit 34 compares the number of communication terminals of the disconnected radio base station 2-n with the number of communicable terminals of the other radio base station 2-n, and whether the number of communication terminals matches the number of communicable terminals. If it is different (NO in S414), the process returns to message reception (S300).

  Next, when the number of communication terminals and the number of communicable terminals match (YES in S414), the control unit 34 determines the number of communication terminals of another radio base station 2-n with the same number of communication terminals and the number of communicable terminals. Reference is made from the communicating terminal ID field 3312 of the communication terminal control table 331 for each base station (S415), and the other wireless bases in which the number of communication terminals, the number of communication terminals, and the number of communicable terminals of the disconnected wireless base station 2-n match. When the number of communication terminals of the station 2-n is compared (S416) and the number of communication terminals of the disconnected radio base station 2-n is smaller (YES in S416), the radio base station 2-n having a smaller number of communication terminals is selected. A TCH switching instruction message is created and transmitted via the call control unit 31 and the base station interface unit 32 (S417). Then, the control unit 34 waits for PBX 3 to receive a message (S400).

  On the other hand, if the local PHS terminal 1-m communicating with the disconnected radio base station 2-n is more common (NO in S416), the control unit 34 communicates with the other radio base station 2-n. A TCH switching instruction message is generated for the local PHS terminal 1-m so as to move to the disconnected radio base station, and the radio base station 2-n is transmitted via the call control unit 31 and the base station interface unit 32. (S418). Then, the control unit 34 waits for PBX 3 to receive a message (S400).

  FIG. 4 shows this series of flows as an example. When the call is released from the local PHS terminal 1-1 that is communicating with the radio base station 2-1, the control unit 34 disconnects the radio base station 2-1. Are communicating with the local PHS terminals 1-2 and 1-3, and the other wireless base station 2-2 has two communicable units. The number of communicable units becomes equal.

  The control unit 34 communicates with the other radio base station 2-2 by one of the local PHS terminals 1-4, and the local PHS with which the disconnected radio base station 2-1 is communicating. Since the number is less than the number of terminals 1-m, a TCH switching instruction is sent to the local PHS terminal 1-4 communicating with the other radio base station 2-2 so as to move to the radio base station 2-1. .

  Next, when receiving the call setup message of the received message (“call setup” in S401), the control unit 34 receives the number of communicable terminals in the base station-specific communication terminal control table 331 of the radio base station 2-n. It is determined whether 3314 is “0” (S421).

  Then, when the communicable terminal number field 3314 of the received base station-specific communication terminal control table 331 of the radio base station 2-n is “0” (YES in S421), the control unit 34 determines that the radio base station 2- A connection rejection message is sent to n (S422), and it is confirmed whether there is an adjacent radio base station 2-n (S423). If there is no adjacent radio base station 2-n (NO in S423), PBX3 is received as a message (S400) Wait.

  When there is an adjacent radio base station 2-n (YES in S423), the control unit 34 indicates that the activation state field 3313 of the base station-specific communication terminal control table 331 of the adjacent radio base station 2-n is “stopped”. If the activation status field 3313 is “active” (NO in S424), the PBX 3 waits for message reception (S400), and the activation status field 3313 is “stopped” (S424). YES), the control unit 34 creates a transmission / reception restart message to the adjacent radio base station 2-n, transmits it via the call control unit 31 and the base station interface unit 32 (S425), and receives the PBX 3 as a message. (S400) Wait.

  When this series of flows is shown as an example in FIG. 5 together with FIG. 4, when the control unit 34 of the PBX 3 receives a call setup message from the radio base station 2-1 (S202), the control unit 34 of the radio base station 2-1 Since the communicable terminal number field 3314 of the base station-specific communication terminal control table 331 is “0”, a connection rejection message is transmitted to the radio base station 2-1 (S204). Then, the control unit 34 refers to the adjacent radio base station 2-2 whose activation state is “stopped” from the base station-specific communication terminal control table 331, and transmits a transmission / reception restart message (S207).

  On the other hand, the control unit 34 receives the received message when the communicable terminal number field 3314 of the communication terminal control table 331 for each base station of the radio base station 2-n that has received the call setting message is not “0” (NO in S421). Receives a call setup acceptance message or a radio base station 2-n synchronization completion message (“call setup acceptance or synchronization completion notification” in S401), the ID of the local PHS terminal 1-m that has started communication is entered. The value is stored in the communicating terminal ID field 3312 of the record 3315 of the message transmission source radio base station 2-n of the base station-specific communication terminal control table 331 and the value decremented in the communicable number field 3314 is stored (S431).

  Then, in all the wireless base stations 2-n that are connected, the control unit 34 has one ID of the local PHS terminal 1-m in the communicating terminal ID field 3312 of the communication terminal control table 331 for each base station. The wireless base station 2-n that is not stored is searched (S432).

  Here, the control 34 waits for message reception (S400) when the corresponding base station is not found in the search (NO in S433).

  On the other hand, if there is a corresponding base station (YES in S433), since the wireless base station 2-n is not communicating with the local PHS terminal 1-m, a transmission / reception stop message is created and the call control unit 31 Then, the data is transmitted to the radio base station 2-n via the base station interface unit 32 (S434). Then, the control unit 34 waits for message reception (S400).

  The embodiment of the present invention has been described above.

  In the present embodiment, it is possible to save power by efficiently stopping radio transmission / reception in the radio base station 2-n in the local radio telephone system.

  That is, in the local radio telephone system, the PBX 3 determines the communication status between the radio base station 2-n and the local PHS terminal 1-m from the base station-specific communication terminal control table 331, and the number of local PHS terminals 1-m in communication. Is limited to the number of radio base stations 2-n that can be accommodated, and if the number of radio base stations 2-n can be accommodated, the local PHS terminal is connected via the radio base station 2-n in communication An instruction to move 1-m to the radio base station 2-n is given.

  In the local radio telephone system, the PBX 3 instructs the radio base station 2-n that is not used for communication to stop radio transmission and reception so that the power consumption of the radio base station 2-n can be saved.

  At this time, when the radio base station 2-n has the clock unit 25, the number of calls of the local PHS terminal 1-m increases, and when the radio transmission / reception of the stopped radio base station 2-n is resumed, A radio base station 2-n that generates radio transmission / reception timing from a clock and enables communication.

  The instruction to move the radio base station 2-n of the local PHS terminal 1-m specifies the number of communicating terminals of the radio base station 2-n from the base station-specific communication terminal control table 331, and the base station-specific communication terminal control. When the number of communicating terminals is smaller than the number of communicable terminals 3314 from the number of communicable terminals 3314 in the table 331, the local PHS currently communicating among the local PHS terminals 1-m belonging to the radio base station 2-n. The terminal 1-m is instructed to move the number of communicable terminals 3314 to another wireless base station 2-n that matches the number of communicating base stations of the wireless base station 2-n. When the number of possible terminals 3314 is larger than the number of communicable terminals 3314, the local PHS terminal 1 in communication among the local PHS terminals 1-m belonging to the other radio base station 2-n whose number of communicable terminals 3314 matches the number of terminals in communication Radio base for -m It is instructed to move to station 2-n. Thereby, the local PHS terminal 1-m to be moved is reduced, the time required for movement is shortened, and the radio base station 2-n that is not used for communication can be prepared quickly, thereby enhancing the power saving effect.

  The present invention is not limited to the above-described embodiment, and can be applied to various radio systems within the scope of the gist.

  For example, in the present embodiment, the local PHS system has been described as an example, but the present invention can be applied to various wireless systems. For example, in the overall configuration of the local wireless telephone system using the local PHS terminal 1-m shown in FIG. 1, the local PHS terminal 1-m is a wireless IP phone or a wireless IP terminal, and the wireless base station 2-n is an access pointer. It may be constructed.

  In the present embodiment, PBX 3 transmits a TCH switching instruction command to terminal 1 based on the function of RCR STD-28, and terminal 1 that has received the command changes the attribution destination according to the command. However, for example, it may be controlled not to transmit a TCH switching instruction command to the terminal 1 but to reduce or stop the transmission power of the beacon transmitted from the radio base station 2 instead. Since the terminal changes or performs handover from the radio wave intensity of the beacon transmitted from the wireless base station 2, there is an effect that even a wireless system that does not have a switching instruction function can save power. Further, when this method is used, there is no need for the base station-specific communication terminal control table of FIG. In the case of the present embodiment, the number of communicable terminals is monitored for each radio base station 2, and when there is a radio base station 2 that can be accommodated, a TCH switching instruction is given to the terminal 1 belonging to the radio base station 2 Send the command. Therefore, for example, when three wireless base stations 2 are connected to the PBX 3, there are two terminals that can communicate with one wireless base station, and there are terminals that can communicate with only one other wireless base station 2. Can not be integrated. On the other hand, according to this method, since the terminal automatically changes the belonging destination or performs handover, the terminal can be accommodated.

  In the present embodiment, in a local PHS system in which the number of local PHS terminals 1-m capable of communicating with one radio base station 2-n is as few as two, two radio base stations 2- The power consumption between the wireless base stations is reduced, but in the wireless base station such as an access pointer capable of communicating the number of wireless terminals of N with respect to one wireless base station, the wireless base stations are communicating with each other. Monitor the number of terminals, identify radio base stations that are less than K (K <N), identify radio base stations that are communicating with more than K radio terminals and the number of communicable radio terminals is not “0” By moving a wireless terminal in communication to a wireless base station capable of communication, power supply to the wireless base station that has performed communication can be stopped to save power.

  In the present embodiment, the radio base station 2 connected to the PBX 3 is limited to accommodating radio terminals in the same cell area, but the present application is not limited to this. For example, the PBX 3 may be arranged such that the cell areas of the plurality of radio base stations 2 are different and cover each other. In this case, the PBX 3 prepares a table of the field of the radio base station 2 to which the terminal 1 can belong and the field of the field of the radio base station to which the terminal 1 belongs, instead of the table of FIG. Then, the records for each terminal 1 are sorted in the order of the radio base station to which the terminal belongs, the record having only one radio base station to which the terminal belongs is selected, and the record belonging to the field of the radio base station 2 to which the record belongs can be selected. When a wireless base station other than the wireless base station exists, beacon transmission of the wireless base station is stopped. This can be realized even when the cell areas are different.

1 PHS terminal 2 Wireless base station 3 PBX (main unit)
4 public network 20 antenna unit 21 wireless transmission unit 22 wireless reception unit 23 PBX command control unit 24 PBX interface unit 25 clock unit 26 power supply control unit 27 control unit 31 call control unit 32 base station interface unit 33 storage unit 34 control unit 321 interface Unit 322 base station power supply control unit 331 base station-specific communication terminal control table

Claims (1)

In a private radiotelephone system comprising a plurality of radio terminals, a plurality of radio base stations accommodating the plurality of radio terminals, and a private branch exchange accommodating the plurality of radio base stations,
The private branch exchange includes: a call monitoring unit that monitors the number of calls relayed by each of the wireless base stations; and a wireless base station that identifies a wireless base station whose number of relayed calls is less than K (K <N) A wireless terminal specifying means for specifying a wireless terminal making a call via the specified wireless base station; and a wireless terminal other than the wireless base for making a wireless terminal making a call via a predetermined wireless base Via a radio base station having handover means for executing handover to a station and radio base station power supply stopping means for stopping power supply to a predetermined radio base station, wherein the number of calls being relayed is less than K A radio terminal that is talking is identified, a handover is performed to a radio base station other than the radio base station that relays the radio terminal and the number of calls that are relayed is K or more, and the identified radio terminal To the radio base station that was relaying the call Supplying a stop,
Each of the plurality of wireless terminals executes handover to one of the plurality of wireless base stations designated by the private branch exchange when instructed to perform handover from the private branch exchange. On-premises wireless telephone system.

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