JP2013207599A - Mobile communication system, base station and communication control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile communication system, a base station and a communication control method, capable of providing high-speed data communication and a minimum communication service to a multiplicity of user terminals.SOLUTION: A base station 100 controls to perform continuous radio communication with a mobile station 10, when the number of mobile stations 10 to be connected is a first threshold or larger, or when the number of connection requests is a second threshold or larger, so as to accept a connection request from the mobile station 10 in a manner to perform radio communication with the maximum number of mobile stations connectable from the own station. When the number of mobile stations 10 to be connected is smaller than the first threshold or the number of connection requests is smaller than the second threshold, the base station 100 controls to perform radio communication with the mobile station 10 at predetermined time intervals, and controls to hand over the mobile station 10 to another base station that continuously performs radio communication when suspending transmission output.

Description

  The present invention relates to a mobile communication system, a base station, and a communication control method that provide a radio communication service to a mobile station.

  In the mobile communication system, the area coverage is improved by providing services at a plurality of base stations. In addition, in order to reduce areas where communication cannot be established, service areas of a plurality of base stations are overlapped. However, due to the influence of radio signals transmitted from a plurality of base stations, there may be cases where interference occurs with each other and the call quality deteriorates. Therefore, interference is prevented by controlling the transmission output of the radio signal transmitted by each base station or limiting the direction in which the radio signal is transmitted (for example, Patent Document 1).

JP 2004-207840 A

  However, in an area where base stations are crowded, the influence of other base stations cannot be sufficiently reduced, and each base station is operated with interference. For this reason, problems such as a decrease in line connection rate and inability to perform high-speed communication occur. Especially when traffic increases suddenly, all neighboring base stations can accommodate many users, so the output cannot be limited, and a base station that employs an adaptive array cannot fully exercise its control. It has become.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a high-speed data communication to a user terminal or to provide a minimum number of communication services even when traffic rapidly increases. It is an object to provide a mobile communication system, a base station, and a communication control method that can be provided to other user terminals.

  In order to achieve the above object, the present invention is a mobile communication system comprising a plurality of base stations, wherein the base station is connected to the own station or the number of connection requests from the mobile station. If the number of mobile stations connected to the mobile station is less than the first threshold or the number of connection requests from the mobile station is less than the second threshold, wireless communication between the mobile station and the mobile station When the number of mobile stations connected to the local station is controlled to be performed at frame intervals and the number of connection requests from the mobile station is equal to or greater than the second threshold, the radio between the local station and the mobile station Control is performed so that communication is performed every frame.

  When the number of mobile stations connected to the base station is equal to or greater than the first threshold, or the number of connection requests from the mobile station is equal to or greater than the second threshold, the base station is the maximum number of mobile stations that can be connected to the base station. It is preferable to accept a connection request from a mobile station so as to communicate wirelessly.

  The base station performs wireless communication with the mobile station every frame when the number of mobile stations connected to the base station is less than a first threshold value or when the number of connection requests from the mobile station is less than a second threshold value. It is preferable to control to be handed over to the base station.

  The present invention is also a base station in a mobile communication system, wherein the number of mobile stations connected to the own station or the number of connection requests from the mobile station is acquired, and the number of mobile stations connected to the own station is the first. Mobile station connected to the mobile station by controlling to perform wireless communication between the mobile station and the mobile station at a predetermined frame interval when the number of connection requests from the mobile station is less than the second threshold. When the number is equal to or greater than the first threshold value or the number of connection requests from the mobile station is equal to or greater than the second threshold value, control is performed such that wireless communication between the mobile station and the mobile station is performed in each frame.

  The present invention is also a communication control method for a base station in a mobile communication system, the step of acquiring the number of mobile stations connected to the own station or the number of connection requests from the mobile station, and the connection to the own station Controlling to perform wireless communication between the mobile station and the mobile station at a predetermined frame interval when the number of mobile stations is less than the first threshold or when the number of connection requests from the mobile station is less than the second threshold; When the number of mobile stations connected to the local station is equal to or greater than the first threshold value or the number of connection requests from the mobile station is equal to or greater than the second threshold value, wireless communication between the local station and the mobile station is performed in each frame. And a step of controlling.

  According to the present invention, since the influence of interference can be reduced, a high-speed data communication can be provided to a user terminal (mobile station), or a minimum communication service can be provided to a large number of user terminals (mobile stations) even when traffic rapidly increases. ) Can be provided.

It is a schematic block diagram of the radio | wireless communications system containing the base station which concerns on embodiment of this invention. It is a figure explaining the operation control of the base station which performs radio | wireless communication in a predetermined time interval, and the base station which performs radio | wireless communication continuously. It is a flowchart explaining operation | movement of the base station which performs radio | wireless communication by a predetermined time interval. It is a flowchart explaining the operation | movement of a transmission stop process. It is a flowchart explaining operation | movement when the base station which performs radio | wireless communication continuously performs call connection aggregation processing.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a radio communication system including a base station according to an embodiment of the present invention. The wireless communication system shown in FIG. 1 includes mobile stations 10-1 to 10-n (hereinafter referred to as mobile stations 10) and base stations 100 as user terminals. Note that although external devices such as a network and a server are connected to the base station 100, description of these external devices is omitted.

The base station 100 includes a wireless communication unit 110, a control unit 120, an IF (interface) unit 130, and a storage unit 140.
For example, the radio communication unit 120 performs adaptive array control using a plurality of antenna elements and transmits and receives radio signals to and from the plurality of mobile stations 10.
The IF unit 130 transmits / receives data to / from another base station via a network, a server, or the like.
The storage unit 140 includes a predetermined number of mobile stations 10 connected to the own station (first threshold), a predetermined number of connection requests from other mobile stations 10 (second threshold), and The maximum number of mobile stations 10 that can be connected to the own station is stored.

  The control unit 120 obtains the number of mobile stations 10 connected to the local station or the number of connection requests from the mobile station 10, and the number of mobile stations 10 connected to the local station is less than the first threshold value or moves When the number of connection requests from the station 10 is less than the second threshold, the mobile station 10 is controlled to perform wireless communication at a predetermined time interval (frame interval) and moves to connect to the own station. When the number of stations 10 is equal to or greater than the first threshold value or the connection request from the mobile station 10 is equal to or greater than the second threshold value, wireless communication between the mobile station 10 and the mobile station 10 is continued (in each frame). To control.

  In addition, when the number of mobile stations 10 connected to the own station is equal to or greater than the first threshold or the connection request from the mobile station 10 is equal to or greater than the second threshold, the control unit 120 A connection request from the mobile station 10 is accepted so as to wirelessly communicate with a number of mobile stations.

  In addition, the control unit 120, when the number of mobile stations 10 connected to the own station is less than the first threshold value or when the connection request from the mobile station 10 is less than the second threshold value, On the basis of the information related to the above, control is performed so as to be handed over to a base station that continues (per frame) wireless communication with the mobile station 10.

  FIG. 2 is a diagram for explaining operation control of a base station that performs wireless communication with the mobile station described above at a predetermined time interval (frame interval) and a base station that performs wireless communication with the mobile station continuously (every frame). It is.

When a base station that performs wireless communication at a predetermined time interval (frame interval) stops transmission output, it continuously performs wireless communication (every frame) to a mobile station connected to the base station. A handover process for switching to the neighboring base station is performed, and when all the mobile stations are switched to the neighboring base station, the operation is stopped.
In addition, a base station that performs wireless communication at a predetermined time interval (frame interval) (a base station that is stopped) switches operation in order by setting a time. In this operation switching, the host device (for example, the management server) acquires information on the operating state including the number of connections and the number of connection requests in each base station, and determines the order of switching the operation from the acquired information. Also good.

  Next, the operation of the base station that performs wireless communication at a predetermined time interval (frame interval) will be described based on the flowchart of FIG.

  The control unit 120 of the base station 100 starts an activation wait timer so as to perform wireless communication between the own station and the mobile station 10 at a predetermined time interval (for example, 2 to 10 minutes) (S101). Next, the control unit 120 determines whether or not a predetermined time interval has passed, that is, whether or not the timing for starting the own station has come (S102), and when it is not the startable timing (in the case of No in S102) ) Keeps the transmission output stopped (S103). At this time, the mobile station 10 may be notified of the connectable waiting time.

  If it is the startable timing (Yes in S102), the control unit 120 starts an operation time timer (S104). The set value of the operating time timer is, for example, 2 to 10 minutes. Next, the control unit 120 transmits a control signal (S105) and performs a start start process (S106).

  The control unit 120 determines whether or not there is a connection request from the mobile station 10 (S107). If there is a connection request (Yes in S107), the control unit 120 performs call connection processing (S108) and maintains the call. (S109). When there is no connection request (No in S107), the control unit 120 determines whether or not the operating time timer has expired (S110). If the time is up (Yes in S110), transmission stop processing is performed (S110).

  Next, the operation of the transmission stop process in S110 will be described based on the flowchart of FIG. The control unit 120 checks whether there is a mobile station 10 connected to the own station (S201). When there is no connected mobile station 10 (No in S201), the control unit 120 stops transmission output (S205). When there is a connected mobile station 10 (Yes in S201), the control unit 120 continues to the connected mobile station 10 to another base station that performs wireless communication (every frame). The handover request process is performed (S202), and the mobile station 10 is controlled to be handed over (S203). Next, the control unit 120 confirms whether or not the handover of all the connected mobile stations 10 has been completed (S204), and when the handover is completed (Yes in S204), the transmission output Is stopped (S205).

  Next, an operation when a base station that performs wireless communication continuously (in each frame) performs call connection aggregation processing will be described with reference to the flowchart of FIG. The control unit 120 confirms whether or not it is the operable timing (S301), and ends the process if it is not the operable timing (No in S301). When it is the operable timing (Yes in S301), the control unit 120 checks whether there is an empty wireless communication channel (S302), and when there is no empty channel (No in S302). , Return to S301. If there is an empty channel (Yes in S302), the control unit 120 checks whether there is a handover request from another base station (S303), and if there is no handover request (No in S303). ), The process returns to S301. If there is a handover request (Yes in S303), a handover process is performed to accommodate mobile stations of other base stations (S304).

  As described above, in the wireless communication system according to the present invention, the number of connected mobile stations and the base station with a large number of connection requests are preferentially operated, and the number of connected mobile stations in other neighboring base stations. In addition, the base station with a small number of connection requests is operated intermittently to reduce interference during a sudden increase in traffic. A station with a large number of connected mobile stations performs processing to increase the number of connected mobile stations to the limit of the limited capacity, and a base station with a small number of connected mobile stations performs handover processing to a base station with a large number of connected mobile stations nearby. Control to promote.

  However, if the balance of operation time varies greatly, such as when only a specific base station is in operation at all times and the stop time of other neighboring base stations increases, the connection rate in areas with less operation time will decrease, so a certain amount of time will be required. The base stations that are determined and operated are switched in order to prevent a decrease in the connection rate in the entire area.

  Therefore, before the predetermined time elapses, control is performed to perform a handover process for switching a mobile station connected to the local station to another neighboring base station and to switch the mobile station connected to the local station to another base station. When all mobile stations are switched to other base stations, the operation is stopped. The user of the mobile station estimates the timing when the line can be connected and makes a call to improve the success rate of the connection. At this time, the mobile station may be provided with a service such as sending a message to the effect that connection will be possible.

  In the event of a special event such as an earthquake disaster, the user terminal (mobile station) sends a message to the effect that automatic disconnection will be performed after a certain period of time immediately after connection, limiting the possible line continuation time to a few minutes. The service is provided so that it can be used by many users by preventing the line from being occupied for a long time by disconnecting it after a certain time. The possible line continuation time is set to about 3 minutes, for example.

  At this time, the base station near the user terminal to be connected should immediately connect if the local station is in an active state, and can be connected in 3 minutes if the local station is in a stopped state. Is notified to the user terminal, and the user tries to connect after 3 minutes to ensure the connection. This makes it possible to eliminate the user's anxiety that the user does not know when to connect. For the notification to the user terminal, a method of “out of service area” notification by stopping the control channel (CCH) of the neighboring base station and a method of notification of the connectable waiting time “remaining 3 minutes” are used.

According to the present invention, since the influence of interference can be reduced, it is possible to provide high-speed data communication to user terminals, or to provide a minimum communication service to many user terminals even when traffic rapidly increases. .
Further, according to the present invention, even when a base station is damaged, the service can be supplemented by neighboring base stations.

DESCRIPTION OF SYMBOLS 10 Mobile station 100 Base station 110 Wireless communication part 120 Control part 130 IF (interface) part 140 Storage part

Claims (5)

A mobile communication system comprising a plurality of base stations,
The base station
Get the number of mobile stations connected to your station or the number of connection requests from your mobile station.
When the number of mobile stations connected to the own station is less than the first threshold or the number of connection requests from the mobile station is less than the second threshold, wireless communication between the own station and the mobile station is performed at a predetermined frame interval. Control and
When the number of mobile stations connected to the local station is equal to or greater than the first threshold or the number of connection requests from the mobile station is equal to or greater than the second threshold, control is performed so that wireless communication between the local station and the mobile station is performed every frame. A mobile communication system characterized by that.   When the number of mobile stations connected to the base station is equal to or greater than the first threshold, or the number of connection requests from the mobile station is equal to or greater than the second threshold, the base station is the maximum number of mobile stations that can be connected to the base station. The mobile communication system according to claim 1, wherein a connection request from a mobile station is received so as to wirelessly communicate with the mobile communication system.   The base station performs wireless communication with the mobile station every frame when the number of mobile stations connected to the base station is less than a first threshold value or when the number of connection requests from the mobile station is less than a second threshold value. The mobile communication system according to claim 1, wherein the mobile communication system is controlled to be handed over to a base station. A base station in a mobile communication system,
Get the number of mobile stations connected to your station or the number of connection requests from your mobile station.
When the number of mobile stations connected to the own station is less than the first threshold or the number of connection requests from the mobile station is less than the second threshold, wireless communication between the own station and the mobile station is performed at a predetermined frame interval. Control and
When the number of mobile stations connected to the local station is equal to or greater than the first threshold or the number of connection requests from the mobile station is equal to or greater than the second threshold, control is performed so that wireless communication between the local station and the mobile station is performed every frame. A base station characterized by that. A base station communication control method in a mobile communication system, comprising:
Acquiring the number of mobile stations connected to the own station or the number of connection requests from the mobile station;
When the number of mobile stations connected to the own station is less than the first threshold or the number of connection requests from the mobile station is less than the second threshold, wireless communication between the own station and the mobile station is performed at a predetermined frame interval. The step of controlling
When the number of mobile stations connected to the local station is equal to or greater than the first threshold or the number of connection requests from the mobile station is equal to or greater than the second threshold, control is performed so that wireless communication between the local station and the mobile station is performed every frame. And steps to
The communication control method characterized by including.

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