JP2008113063A - Communication base station device, and convergence avoiding method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein communication exceeding line capacity is required since many users telephone for emergency communication and securing safety simultaneously in a disaster, such as an earthquake, and hence a state that is called convergence disabling communication occurs and especially the convergence can occur easily in the communication of a circuit switching system, such as speech communication. <P>SOLUTION: A base station monitors the occurrence of quake continuously by an acceleration sensor. When a large quake is monitored, the base station performs convergence avoidance communication control autonomously without waiting for control from an upper communication network. Control is made so that the radius of a zone becomes large autonomously, and control for giving multiperson small-capacity communication priority over small number of person large-capacity communication control. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a communication base station apparatus and a congestion avoiding method for avoiding congestion of the communication base station apparatus.

  In wireless communication such as PHS (Personal Handy-phone System), signal processing called modulation is performed on voice and data exchanged between a base station and a plurality of users connected to the base station, and the signal is communicated. Communication is performed by converting to a frequency band.

  In recent years, there is a communication method called an adaptive modulation method in which communication is performed by appropriately changing a modulation method in accordance with a communication environment in order to increase a data rate during communication. This adaptive modulation method is a modulation method capable of sending data at a higher speed or data transmission at a lower speed according to the level of the interference wave for the signal to be communicated or the level of the signal transmitted from the other party. Communication is performed while changing to a modulation method. There are modulation schemes such as BPSK, QPSK, 16QAM, and 64QAM in ascending order according to the data rate (transfer rate). These modulation schemes are also called modulation classes, and BPSKQPSK is generally called a low class and 16QAM or 64QAM is called a high class.

  Here, the relationship between these modulation schemes and the communicable area of the base station will be described. In this case, a higher signal level (radio wave intensity) is required because the higher the modulation method, the greater the influence of interference waves and signal level changes. If the intensity of a signal (radio wave) transmitted from a base station such as PHS is constant, the faster the modulation method, the closer the communication to the base station.

  In FIG. 2, the communicable area 1 centered on the base station 1 is indicated by a circle. This figure is a bird's-eye view, and the communicable area is represented by an ellipse.

  In the communicable area 1, a portion where the BER (Bit Error Rate) indicating the reliability of data communication is a specified value BER1 or more is indicated by hatching. A radius of a circle in which the ratio of the shaded area to the communicable area 1 is a certain value P1 is defined as a zone radius R. Here, when QPSK is used as the modulation scheme, the zone radius at which P1 = 10% is R0, and the zone radius at which P1 = 10% in each modulation scheme is expressed as a ratio to R0, 0.65R0 at 16QAM. , 64QAM is 0.49R0. This is shown in FIG. Note that P1 is called a deterioration rate.

  As shown in FIG. 3, it can be seen that the zone radius R can be increased as the modulation class becomes lower. Accordingly, in one base station, the zone radius becomes larger as the modulation class is lower than the higher modulation class, and more users can be accommodated.

  By the way, in the event of a disaster such as an earthquake, many users call all at once to ensure urgent contact and safety, so communication exceeding the line capacity is required, and as a result, a state called communication congestion that prevents communication is generated. . In this case, data communication such as e-mail falls into a situation where it is difficult to communicate due to the influence of congestion.

Patent Document 1 listed below is a mobile phone having an Internet connection function and an e-mail transmission / reception function, and includes one or more types of means for detecting an abnormal situation or an emergency situation, and information on the detected abnormal situation or emergency situation. A technology related to a mobile phone that receives and transmits a message is disclosed. Further, in Patent Document 2 below, the base station transmits a communication restriction message for selectively prohibiting transmission via a broadcast channel to the mobile station, so that the mobile station prohibits transmission and “location registration”. A technique for transitioning to a regulation standby mode without performing the process is disclosed.
JP 2005-311995 A By the way, the PHS base station apparatus is small and light because of its small output, and is often installed outdoors such as a utility pole or the rooftop of a building. For this reason, it is more susceptible to external influences such as wind and earthquakes compared to devices installed indoors, and the failure rate is high.

  For this reason, some conventional base station apparatuses include a maintenance diagnosis unit in the base station apparatus. When the maintenance diagnosis unit monitors the internal state of the base station apparatus and detects the occurrence of a failure, it attempts to recover autonomously. The maintenance diagnosis unit also has a function of notifying the base station management device, which is a higher-level device, of information related to the occurrence or recovery of a failure.

  As described above, in the event of a disaster such as an earthquake, a state in which communication called congestion occurs is impossible because many users call all at once for emergency communication and ensuring safety. In particular, when a base station that communicates with a modulation method with a high modulation class is adjacent to a base station that communicates with a low-class modulation method, communication is performed with a low-class modulation method with a large zone radius. The user concentrates on the base station. As a result, the number of communication channels that can be allocated in packet communication, which is data communication for transmitting e-mail and the like, is reduced, so that many transmission waits occur and the overall throughput is significantly reduced.

  A conventional base station apparatus does not have a function of performing control for avoiding congestion on its own in response to the occurrence of such congestion, and cannot autonomously perform fine congestion avoidance control. The base station apparatus performs congestion avoidance control in accordance with instructions and commands related to congestion avoidance control from the base station management apparatus that is the host apparatus. In addition, when some kind of communication failure occurs and an abnormality occurs in the connection with the higher-level communication network, the congestion avoidance control instruction cannot be received and it is not possible to shift to the congestion avoidance control.

  The present invention has been made in view of the above-described conventional problems, and in particular, environmental information in which the base station apparatus collected by the base station apparatus itself at the time of a disaster that causes the base station apparatus to shake, such as an earthquake or a typhoon, It is an object of the present invention to provide a base station apparatus and a congestion avoidance method for the base station apparatus that can perform congestion avoidance control suitable for the base station apparatus based on information related to shaking.

  In order to achieve the above object, a communication base station apparatus according to the present invention communicates with a wireless communication terminal by appropriately using a plurality of modulation schemes, and environment information acquisition means for acquiring environment information of the communication base station apparatus; And a congestion avoiding means for avoiding communication congestion related to the communication base station apparatus, and a congestion avoiding control means for controlling the congestion avoiding means in accordance with the acquired environment information.

  In one aspect of the present invention, the congestion avoiding means changes the modulation method according to the acquired environment information.

  In one aspect of the present invention, the congestion avoiding means changes the modulation method so as to expand a callable range when the acquired environment information exceeds a predetermined value.

  In one aspect of the present invention, the environment information acquisition unit is a vibration sensor that detects vibration information.

  Furthermore, in one aspect of the present invention, the vibration information includes a seismic intensity at the time of occurrence of the earthquake.

  Further, the present invention is a communication congestion avoidance method in a communication base station apparatus that communicates with a wireless communication terminal by appropriately using a plurality of modulation schemes, and includes the step of acquiring environment information of the communication base station; The method includes a step of avoiding congestion of communication related to a base station, and a congestion avoidance control step of controlling a step of avoiding the congestion according to the acquired environment information.

  According to the base station apparatus and the congestion avoidance method of the base station apparatus according to the present invention, based on the environmental information collected by the base station apparatus itself, in particular, information on shaking, congestion avoidance communication control suitable for the base station apparatus is performed. Can do. Further, it is possible to predictively perform congestion avoidance control before congestion starts. Furthermore, even if the instruction from the upper management device regarding congestion avoidance control does not come due to some kind of communication failure, etc., if the base station device observes shaking, it can autonomously perform congestion avoidance communication control and secure the number of lines. It is possible to facilitate emergency contact and safety confirmation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram of the base station apparatus 1. The base station apparatus 1 includes an external interface unit 11, a signal processing unit 12, a modem unit 13, a radio unit 14, an avoidance control unit 16, an acceleration calculation unit 17, and an acceleration sensor 18.

  A control unit (not shown) includes an operation management unit, a radio control unit, and a line control unit, and includes a CPU, a memory, and the like, and performs control related to the operation of the base station apparatus 1 as a whole.

  The wireless communication unit 14 includes an antenna 15, is connected to the transmission rate switching unit 13, and is connected to the external interface unit 11 via the signal processing unit 12. The radio unit 14 receives a signal from each communication device 2 received by the antenna 15 and converts the signal into a signal that can be processed by the modem unit 13 and the signal processing unit 12. The modulation / demodulation unit 13 determines the modulation method according to the signal received by the radio unit 14 and demodulates it, and sends the signal extracted for each user to the signal processing unit 12. The signal processing unit 12 demodulates the reception signal demodulated by the modulation / demodulation unit, extracts the packet, and outputs the packet to the external interface unit 11. In addition, a plurality of packets input from the external interface unit 11 are modulated and sent to the modem unit 13. The modem 13 modulates the signal to be transmitted by switching the modulation method in units of frames according to a control unit (not shown). In addition, the transmission signal is modulated by a modulation scheme corresponding to the handling level of avoidance communication control from the avoidance control unit 16 described later. The modulated signal is sent to the radio unit 14. The radio unit 14 transmits the signal received from the modem unit 13 to each communication device 2 via the antenna 15.

  The external interface unit 11 is connected to a communication network via an ISDN (Integrated Service Digital Network) line, Ethernet (registered trademark) or the like, and connects the base station apparatus 1 and the communication network to each other. The interface unit 11 outputs a packet input from the communication network to the signal processing unit 13 in accordance with an instruction from the control unit. In addition, a plurality of packets input from the signal processing unit 12 are output to the communication network.

  Further, the base station apparatus 1 includes a maintenance diagnosis unit (all not shown) including a failure monitoring unit (tilt notification unit), an antenna diagnosis unit, a line diagnosis unit, and a tilt diagnosis unit. The maintenance diagnosis unit monitors the operating state of each functional block of the base station device 1 and attempts to recover autonomously when it detects the occurrence of a failure. Further, as necessary, the base station management device that is a host device or an online center including the base station management device is notified of information related to the occurrence or recovery of a failure. The failure monitoring unit is connected to the antenna diagnosis unit, the line diagnosis unit, and the inclination diagnosis unit, monitors the diagnosis result input from each diagnosis unit, and notifies the base station management device etc. of information related to the failure etc. as necessary. To do. The antenna diagnosis unit is connected to the failure monitoring unit, and is also connected to the signal processing unit 12, the multiplexing number switching unit 13, and the radio unit 14. And while diagnosing the state of the signal processing part 12, the transmission rate switching part 13, the radio | wireless part 14, and the antenna 15, a diagnostic result is output to a failure monitoring part. The line diagnosis unit is connected to the failure monitoring unit and to the external interface unit 11. Then, the state of the line connected to the base station apparatus 1 is diagnosed, and the diagnosis result is output to the failure monitoring unit. In addition, the maintenance diagnosis unit notifies the information on the gravitational acceleration vector acquired by the acceleration sensor 18 and calculated by the acceleration calculation unit 17, which will be described later, to the base station management device that is the host device or an online center including the base station management device. To do.

  The acceleration sensor 18 is a vibration sensor that detects vibration information. The acceleration calculation unit 17 calculates a gravitational acceleration vector applied to the base station apparatus 1 measured by the acceleration sensor 18 and acquires a correspondence with the time axis of the calculated gravitational acceleration vector. That is, a change in the time direction of the gravitational acceleration vector is acquired. Further, the acquired data on the change in the time direction of the gravitational acceleration vector is stored in a storage unit (not shown). The acceleration sensor 18 is fixed to the base station apparatus 1 and measures the acceleration applied to the base station apparatus 1. The acceleration sensor 18 is a sensor that measures the magnitude of acceleration applied to the attached object. Specifically, the acceleration sensor 18 measures the magnitude and direction of the gravitational acceleration (gravity acceleration vector) and uses the acceleration sensor 18 as a reference. The x, y, and z direction components of the gravitational acceleration vector in the coordinate system are acquired. In the present embodiment, each component of the gravitational acceleration vector measured by the acceleration sensor 18 is used as an acceleration applied to the base station apparatus 1. Here, when the base station apparatus shakes due to an earthquake or the like, the acceleration acquired by the acceleration calculating unit 17 may be an average value of values measured by the acceleration sensor 18 at a predetermined sampling period. By so doing, variations in measurement values related to the gravitational acceleration vector by the acceleration sensor 18 are reduced, and the measurement accuracy is improved.

  The avoidance control unit 16 performs control related to congestion avoidance based on the gravitational acceleration vector calculated by the acceleration calculation unit 17. FIG. 4 shows the handling level of avoidance communication control performed by the operation of the avoidance control unit 16. Information on the gravitational acceleration vector acquired by the acceleration sensor 18 and calculated by the acceleration calculation unit 17 is organized into the following two pieces of information. The first is seismic intensity information (a), and the second is shaking time (b).

a. Seismic intensity: Indicates the maximum acceleration of shaking. A flag is set when the seismic intensity is exceeded.

b. Shake time: Indicates the time during which the acceleration equal to or higher than the predetermined acceleration has been detected. A flag is set when a predetermined shaking time is exceeded. The predetermined acceleration at the time of acquiring the shaking time information may be different from the predetermined seismic intensity when the flag is set in the seismic intensity information (a).

In FIG. 4, a black circle indicates that a flag is set.

  Further, a control unit (not shown) performs a self-diagnosis process of an emergency power source provided in the base station based on the gravitational acceleration vector. The self-diagnosis result is stored in a storage unit (not shown) and can be referred to by the avoidance control unit 16. The avoidance control unit 16 is optimal for the base station based on the relationship between the information seismic intensity of the gravitational acceleration vector calculated by the acceleration calculation unit 17, the shaking time, and the self-diagnosis result performed by the control unit not shown in FIG. Congestion avoidance communication control is performed. In this case, by changing the modulation class to a lower one, the zone radius of the next base station is expanded to accommodate users who were able to communicate only with the adjacent base station. Secure communication lines in case of disasters such as earthquakes by carrying out capacity priority control.

  For example, if the seismic intensity is greater than a predetermined seismic intensity and the shaking time is longer than a predetermined value, the modulation method is set to QPSK or less regardless of the self-diagnosis result of the emergency power supply. That is, when it can be determined that the level of earthquake is severe, the zone radius is expanded using a low modulation class, and control is performed to increase the number of users who can communicate by securing as many lines as possible although the communication speed is not fast. When the seismic intensity is greater than the predetermined seismic intensity and the shaking time is shorter than the predetermined, the modulation class is 16QAM or less regardless of the self-diagnosis result of the emergency power source, and communication is ensured. Furthermore, when the seismic intensity is smaller than the predetermined seismic intensity, the self-diagnosis of the emergency power source is not performed, and if the shaking time is longer than the predetermined, it is set to 64QAM or less. When the seismic intensity and the shaking time are below a predetermined value, adaptive modulation is performed, and adaptive modulation is performed according to the situation.

  Further, the congestion avoidance communication control may be canceled after a predetermined time elapses according to the use status of the line or an instruction from the base station management apparatus that is the host apparatus.

Next, the congestion avoiding operation of the base station apparatus 1 will be described based on the flowchart of FIG.
First, a base station is installed and normal operation is performed (S10). When a shake such as an earthquake occurs, it is determined whether the gravitational acceleration vector applied to the base station calculated by the acceleration calculation unit 17 is equal to or greater than a specified value (S20). If it is not over the limit, return to normal operation. If it exceeds the limit, the avoidance control unit 16 starts congestion avoidance control (S30). At this time, flags are set according to seismic intensity and shaking time. Further, a self-diagnosis of the emergency power source of the base station is executed, and whether it is normal or the voltage is lowered is stored in the storage unit (S40). Subsequently, the countermeasure level of the avoidance communication control is determined using FIG. 4 (S50). Then, the multiplexing number is changed according to the determined handling level (S60). Subsequently, it is confirmed whether the change of the multiplexing number is completed (S70). If not completed, the process returns to S60. If completed, an operation to maintain congestion avoidance control is performed. (S80). Then, it is confirmed whether a predetermined congestion avoidance control time has elapsed. If it has elapsed, the normal operation mode is restored (S110). Even when the time has not elapsed, if there is an instruction from the upper management device to cancel the congestion avoidance control, the normal operation mode is similarly returned to the upset (S110). If there is no cancellation instruction, an operation for maintaining congestion avoidance control is performed.

  According to the base station apparatus and the congestion avoidance method of the base station apparatus described above, it is possible to perform congestion avoidance communication control suitable for the base station based on the shake information collected by the base station itself. Further, it is possible to predictively perform congestion avoidance control before congestion starts. Furthermore, even if an instruction regarding congestion avoidance control from the host management device does not come due to some kind of communication failure, etc., if the base station observes shaking, it can autonomously perform congestion avoidance communication control and secure the number of lines. be able to.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the time for maintaining the congestion avoidance control may be determined according to the handling level of avoidance communication control.

It is a functional block diagram of the base station apparatus which concerns on embodiment of this invention. It is the figure which showed the cell radius and zone radius of the base station. It is a figure showing the deterioration rate with respect to a zone radius. It is the figure which showed the coping level of avoidance communication control. It is a flowchart which shows the operation | movement concerning the congestion avoidance control of a base station apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Base station apparatus, 2 External communication apparatus, 11 External I / F part, 12 Signal processing part, 13 Modulation / demodulation part, 14 Radio | wireless part, 15 Antenna, 16 Avoidance control part, 17 Acceleration calculation part, 18 Acceleration sensor

Claims (6)

In a communication base station apparatus that communicates with a wireless communication terminal by appropriately using a plurality of modulation methods,
Environmental information acquisition means for acquiring environmental information of the communication base station device;
Congestion avoiding means for avoiding communication congestion associated with the communication base station device;
Congestion avoidance control means for controlling the congestion avoidance means according to the acquired environment information;
A communication base station apparatus comprising: The congestion avoiding means changes the modulation method according to the acquired environment information,
The communication base station apparatus according to claim 1. The congestion avoiding means, when the acquired environment information exceeds a predetermined value, changing the modulation method to expand the callable range;
The communication base station apparatus according to claim 1 or 2. The communication base station apparatus according to claim 1, wherein the environment information acquisition unit is a vibration sensor that detects vibration information. The communication base station apparatus according to claim 4, wherein the vibration information includes a seismic intensity at the time of occurrence of the earthquake. A communication congestion avoidance method in a communication base station apparatus that communicates with a wireless communication terminal by appropriately using a plurality of modulation methods,
Obtaining environmental information of the communication base station;
Avoiding communication congestion related to the communication base station;
A congestion avoidance control step for controlling the step of avoiding the congestion according to the acquired environment information;
Congestion avoidance method characterized by including.

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