JP4863320B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a radio communication system, and more particularly to transmission switching control in a radio communication that employs a hot standby system in which priority of an operation system is set and has a function of switching back to an active system.

  In a wireless communication device in the microwave band, a hot standby method is widely adopted in which two transmitters are prepared as active and standby, and one transmitter is normally operated and switched to the other transmitter when a failure occurs.

  FIG. 5 is a block diagram showing a wireless communication apparatus using this type of conventional hot standby system. In FIG. 5, the signal input from the input terminal 1 is modulated by the modulation unit 2 and amplified by the transmission unit 3. Similarly, the signal input from the input terminal 4 is modulated by the modulator 5 and amplified by the transmitter 6.

  The switching control unit 7 detects an abnormality in each unit based on the alarm information 2a, 5a and 3a, 6a detected by the modulation units 2 and 5 and the transmission units 3 and 6, and both the modulation unit and the transmission unit operate normally. The selected system is selected and the switching control information 7a is output. Based on the switching control information 7a output from the switching control unit 7, the transmission switching unit 8 selects one of the output signals that are operating normally in the transmission unit 3 or the transmission unit 6 and selects the transmission antenna 9 And the signal transmitted from the transmission antenna 9 is received by the reception antenna 10.

  The output signal of the reception antenna 10 is branched into two by the distribution unit 11, one of which is amplified by the reception unit 12, demodulated by the demodulation unit 13, and output from the output terminal 14. The other is amplified by the receiver 15, demodulated by the demodulator 16, and output from the output terminal 17.

  Normally, the switching control unit 7 selects a normally operating system based on the input alarm information, and then maintains the previous state even if the system that detected the abnormality returns to normal, and is selected. Although the transmission unit is not switched, the user can arbitrarily select one of the transmission units 3 and 6 as a system with high priority.

  For example, when the transmission unit 3 is set as a high priority system, the transmission unit 6 is selected when either the alarm information 2a from the modulation unit 2 or the alarm information 3a from the transmission unit 3 is detected. After that, when the alarm information 2a, 3a disappears and the transmission unit 3 returns to normal, it has a so-called switch-back function for switching to the transmission unit 3 having a higher priority.

  However, in the conventional wireless communication device described above, when the device selected as a high priority system is in an unstable state that repeats an abnormal state and a normal state, it is unnecessary by repeating the activation / recovery of alarm information. Therefore, there is a problem that a state similar to the occurrence of a line failure occurs because of continuous switching.

  To deal with such problems, the time is stored when the active system becomes faulty and switches from the active system to the standby system, and the active system is in the recovery state and the switch-back control from the standby system to the active system is performed. After execution, when the active system becomes faulty again and switches from the active system to the standby system, the switching occurrence time interval between them is obtained, compared with the preset switching time interval, and switched within this time interval There is a known system in which when the occurrence of this occurs, after switching control to the standby system is performed, control is performed to suppress subsequent switching back.

  However, with this technology, once the switching occurrence time interval falls within the switching time interval, the operation is fixed to the standby system. Therefore, the failure is not repeatedly activated and restored, but switched at a truly short interval. However, there is a problem in that switching is not performed even when it is necessary. Further, since the switchback condition is only the status of the active system, switching is not performed when it is desired to switch to the active system after detecting an abnormality in the standby system. Furthermore, once fixed to the standby system, there is a problem that the automatic failback mode cannot be resumed unless the automatic failback mode is reset.

    JP-A-5-37424

  The problem to be solved is that the switching control becomes rigid with the suppression of unnecessary switching back of the transmission system.

  The main feature of the present invention is to control the switch-back according to the switching monitoring time and the number of switching stops arbitrarily set by the user in order to make the transmission system switching control flexible.

  The wireless communication system according to the present invention avoids unnecessary transmission and standby transmission switching in the hot standby system to prevent deterioration of the line quality, and performs switching back by the switching monitoring time and the number of switching stops set by the user. By controlling, there is an advantage that switching control can be made flexible.

It is a block diagram which shows one Example of the radio | wireless communication apparatus of this invention. It is a block diagram which shows the detail of a switching control part, a control value holding | maintenance part, and a switching monitoring part. It is a figure which displays the determination conditions of transmission system switching. It is a flowchart of a transmission system switching process. It is a block diagram of the conventional radio | wireless communication apparatus.

  FIG. 1 is a block diagram showing an embodiment of a wireless communication apparatus of the present invention, wherein 1 to 17 are the same as FIG. The transmission side of this wireless communication apparatus includes a modulation unit 2 and a transmission unit 3 as one transmission system, a modulation unit 5 and a transmission unit 6 as the other transmission system, and switching control for switching between these two transmission systems. The transmission unit 9 includes a transmission unit 9, a transmission switching unit 8, a control value holding unit 18, a switching monitoring unit 19, a fixed-cycle timer 20, and a transmission antenna 9. The two transmission systems are treated as a working system with a high priority and a standby system with a low priority. The receiving side is not different from that shown in FIG. 5, and includes a receiving antenna 10, a distributing unit 11, receiving units 12 and 15, and demodulating units 13 and 16.

  The modulation unit 2 modulates a signal input from the input terminal 1, and the transmission unit 3 amplifies the output signal of the modulation unit 2. The other modulation unit 5 modulates the signal input from the input terminal 4, and the transmission unit 6 amplifies the output signal of the modulation unit 5.

  The switching control unit 7 detects the abnormality of the corresponding unit based on the alarm information 2a and 5a output from the modulation units 2 and 5 and the alarm information 3a and 6a output from the transmission units 3 and 6, and the modulation unit and the transmission unit Both of them select a system that is operating normally, and output switching control information 7a and switching information 7b unless switching stop information 19a is input. The switching control unit 7 can recognize the currently operating system from the alarm information 2a, 5a and the alarm information 3a, 6a.

  Based on the switching control information 7a output from the switching control unit 7, the transmission switching unit 8 selects one of the output signals of the transmitting unit 3 or the transmitting unit 6 that is operating normally and selects the transmitting antenna 9 And the signal transmitted from the transmission antenna 9 is received by the reception antenna 10.

  The output signal of the receiving antenna 10 is branched into two by the distributing unit 11, the receiving unit 12 amplifies the signal received via the receiving antenna 10, and the demodulating unit 13 demodulates the output signal of the receiving unit 12. And output from the output terminal 14. Similarly, the other receiving unit 15 amplifies the signal received via the receiving antenna 10, and the demodulating unit 16 demodulates the output signal of the receiving unit 15 and outputs it from the output terminal 17.

  In the control value holding unit 18, a switching monitoring time 182a that is a time frame for switching back and a switching stop count 181a that becomes a threshold for stopping switching back can be arbitrarily set by the user. Since switching of the transmission system causes a line failure while avoiding a failure of the transmission system, the switching monitoring time 182a and the number of times of switching stop 181a should be appropriately set according to the trade-off. That is, the switching monitoring time 182a and the switching stop count 181a are determined by the environment and user needs of the wireless communication system, and are set in the control value holding unit 18.

  The switching monitoring unit 19 counts the number of transmission system switchbacks based on the switching information 7 b from the switching control unit 7. When switching back to the active system having a high priority occurs during the switching monitoring time 182a, the switching stop information 19a is output to fix the transmission system to the standby system having a low priority. It should be noted that if the occurrence of switchback in the switching monitoring time 182a is less than the switching stop count 181a, there is no fixing to the standby system, and the switching count starts counting again after the switching monitoring time 182a elapses. This measure allows the user to avoid the occurrence of a line failure due to unnecessary switchback, and to prevent the system from being fixed to the standby system, thereby enabling a flexible system operation.

  The fixed cycle timer 20 outputs the activation signal 20a to the switching control unit 7 and the switching monitoring unit 19 at a fixed cycle, and operates them at a fixed cycle.

  FIG. 2 is a block diagram showing details of the switching control unit 7, the control value holding unit 18, and the switching monitoring unit 19. Referring to FIG. 2, the switching control unit 7 outputs an OR circuit 71 that outputs active alarm information 71a when any of the alarm information 2a or 3a is input, and a standby system when any of the alarm information 5a or 6a is input. The OR circuit 72 that outputs the alarm information 72a, the switching determination unit 73 that outputs the switching information 7b by the alarm information 71a and 72a in response to the activation signal 20a, and the switching information 7b unless the switching stop information 19a is input. It is configured by a switching stop unit 74 that outputs control information 7a. The switching information 7b includes information designating maintenance of the current state, switching to the working system, switching to the standby system, or switching back to the working system. Switching back to the active system is different from switching to the active system in the determination conditions (shown in FIG. 3).

  The control value holding unit 18 includes a switching monitoring time holding unit 182 that holds the set switching monitoring time 182a and a switching stop number holding unit 181 that holds the set switching stop number 181a.

  In addition, the switching monitoring unit 19 responds to the activation signal 20a, counts the switching number 191a with the switching information 7b, and the switching number 191a occurs more than the switching stop number 181a in the switching monitoring time 182a. In this case, the switching stop information 19a is output, and when the switching monitoring time 182a is exceeded, the switching stop determination unit 192 outputs the counter clear information 192a to the switch-over count unit 191. The switching stop determination unit 192 has a built-in switching timer that counts the activation signal 20a, and determines that the switching monitoring time 182a has been exceeded by comparing the value of this switching timer with the switching monitoring time 182a.

  In the following description, it is assumed that the transmission unit 3 is set as a high priority system (active system). FIG. 3 displays transmission system switching determination conditions. If both the alarm information 71a and 72a are OFF and the active system and the standby system are normal, the current status is maintained if the current operation is the active system. However, if the current operation is a standby system, a switchback to the active system occurs. In this case, the standby system is switched to the active system even though it is normal, and the switchback counter 191 is incremented only at this time.

  On the other hand, if the alarm information 71a is OFF and the alarm information 72a is ON and the active system is normal and the standby system is abnormal, the current operation is maintained if the current operation is active. If it is a standby system, switching to the active system occurs. This is a simple switching case, and the number of times of reversion is unchanged. The same applies when the alarm information 71a is ON, the alarm information 72a is OFF, the active system is abnormal, and the standby system is normal.

  FIG. 4 is a flowchart of the transmission system switching process. Based on the transmission system switching determination condition displayed in FIG. 3, the switching determination unit 73 of the switching control unit 7 determines whether or not a switchback to the transmission unit 3 has occurred (step S1 in FIG. 4). When switchback occurs, it is specified by the switching information 7b, so the switchback count counting unit 191 of the switch monitoring unit 19 counts up by 1 (step S2 in FIG. 4). If the number of reversions is less than the number of switching stops 181a (No in step S3 in FIG. 4) and the value of the switching timer is within the switching monitoring time 182a (Yes in step S4 in FIG. 4), The value of the switching timer is incremented by 1 (step S5 in FIG. 4). In this case, failback is executed.

  However, when the switchback count 191a counted by the switchback count counter 191 is equal to or greater than the switching stop count 181a (Yes in step S3 in FIG. 4), the switching stop determination section 192 sends the switching stop information 74 to the switching stop section 74a. Is output to stop the fail-back, and is fixed to the transmission unit 6 as a standby system (step S6 in FIG. 4). Therefore, after that, even if the active modulation unit 2 and the transmission unit 3 return to normal, switching to the transmission unit 3 is not performed.

  When the value of the switching timer becomes equal to or longer than the switching monitoring time 182a (No in step S4 in FIG. 4), the switching-back count unit 191 is cleared to 0 together with the switching timer (step S7 in FIG. 4), and returns to the initial state.

  Note that the procedure shown in FIG. 4 can also be realized by a program executed by the CPU constituting the switching control unit 7 and the switching monitoring unit 19.

  As described above, in the case where switching back occurs more than the switching stop count 181a during the switching monitoring time 182a, unnecessary switching is prevented by fixing the transmission unit to a system with a low priority. At the same time, as a countermeasure when the transmission unit 3 can recover from an unstable state after being fixed to the transmission unit 6, no abnormality is detected in the modulation unit 2 and the transmission unit 3 once in a predetermined period. In this case, it also has a function of canceling the fixed mode of the transmission unit. Since the user can arbitrarily set the release time at this time, it is possible to improve the reliability of the line depending on the situation.

  In addition, the user may arbitrarily release the fixed mode manually. In the above description, the transmission unit 3 is the priority system, but it is needless to say that the transmission switching control according to the present invention can be executed even when the transmission unit 6 is the priority system.

1, 4 Input terminals 2, 5 Modulating unit 3, 6 Transmitting unit 7 Switching control unit 8 Transmission switching unit 9 Transmitting antenna 10 Receiving antenna 11 Distribution unit 12, 15 Receiving unit 13, 16 Demodulating unit 14, 17 Output terminal 18 Control value Holding unit 19 Switching monitoring unit 20 Periodic timers 71 and 72 OR circuit 73 Switching determination unit 74 Switching stop unit 181 Switching stop number holding unit 182 Switching monitoring time holding unit 191 Switching number counting unit 192 Switching stop determination unit

Claims (7)

In a wireless communication device adopting a hot standby method that uses the active system in preference to the standby system,
When an abnormality is detected in the active system or the standby system in operation, switching to the standby system or the active system in a normal state,
Wherein at if the current system during the operation in the standby system resumes using a normal state switchback occurs switched to the active system be the standby system are normal state,
A radio communication apparatus characterized in that when the switchback occurs more than a predetermined number of switching stops during a predetermined switchover monitoring time, the switchback is stopped and fixed to the standby system. In a wireless communication device adopting a hot standby method that uses the active system in preference to the standby system,
A switching control unit that selects a transmission system in which both the modulation unit and the transmission unit of each of the active system and the standby system are operating normally and outputs switching control information and switching information unless switching stop information is input; ,
A transmission switching unit that selects one of the normally operating output signals of the active or standby transmission units according to the switching control information;
A control value holding unit in which the switching monitoring time and the number of switching stops are arbitrarily set by the user;
When the active system is restored to a normal state during operation in the standby system, the number of times of switching back to the active system is counted by the switching information even if the standby system is in a normal state, and the switching monitoring time is obtained. A switching monitoring unit that outputs the switching stop information and fixes the transmission system to the standby system when the number of times of switching back occurs more than the number of switching stops;
A fixed cycle timer that outputs a start signal to the switching control unit and the switching monitoring unit at a fixed cycle and operates at a fixed cycle;
A wireless communication apparatus comprising: The switching control unit
An OR circuit that outputs alarm information input from any of the active modulator and transmitter;
An OR circuit that outputs alarm information input from either the standby modulation unit or the transmission unit;
A switching determination unit that outputs the switching information according to alarm information from the two OR circuits in response to the activation signal;
A switching stop unit that outputs the switching control information according to the switching information unless the switching stop information is input;
The wireless communication apparatus according to claim 2, further comprising: The switching monitoring unit
A reversion number counting unit that counts the number of reversions according to the switching information in response to the activation signal;
A switching stop determination unit that outputs the switching stop information when the number of times of reversion occurs more than the number of times of switching stop within the switching monitoring time, and clears the number of times of reversion counting when the switching monitoring time is exceeded. When,
The wireless communication apparatus according to claim 2, further comprising:   The switching stop determination unit includes a switching timer that counts the activation signal, and determines whether the switching monitoring time is exceeded by comparing a value of the switching timer with the switching monitoring time. Item 5. The wireless communication device according to Item 4. A transmission system switching control method in a wireless communication device adopting a hot standby method in which an active system is used in preference to a standby system,
The procedure for the user to arbitrarily set the switching monitoring time and switching stop count,
Based on the alarm information input from the active system, the alarm information input from the standby system, and information indicating whether the current operation is the active system or the standby system, the active system is operating normally in the standby system. A procedure for determining whether or not a switchover to the active system occurs even when the standby system is in a normal state when the state is restored ;
A procedure for incrementing the number of times of reversion when the reversion occurs, and
A procedure for stopping the switch-back when the switch-back count is greater than or equal to the switching stop count;
A procedure in which the switching timer is incremented by one when the number of switchbacks is less than the switching stop count and within the switching monitoring time;
A transmission system switching control method, comprising: a step of clearing the number of times of switching back and the switching timer when the switching monitoring time is exceeded. A transmission system switching control program executed in a wireless communication device adopting a hot standby method that uses the active system in preference to the standby system,
Based on the alarm information input from the active system, the alarm information input from the standby system, and information indicating whether the current operation is the active system or the standby system, the active system is operating normally in the standby system. Determining whether or not a switchover to the active system has occurred even if the standby system is in a normal state when returning to a state ; and
A step of incrementing the number of times of reversion when the reversion occurs, and
Stopping the failback when the failback count is equal to or greater than a predetermined number of switching stops;
A step of incrementing a switching timer by one when the number of times of switching back is less than the number of times of switching stop and within a predetermined switching monitoring time;
A transmission system switching control program comprising the step of clearing the switching count and the switching timer to zero when the switching monitoring time is exceeded.

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