Wireless communication system, wireless communication method, and wireless communication device

Abstract

The present invention relates to a wireless communication system suitable for stably securing transmission capacity in a multiplex transmission system using a plurality of channels, and the purpose of the present invention is to secure a desired transmission capacity even if some channels become unusable. A wireless communication device and a communication partner device establish communication by multiplexing a plurality of channels, and each have a function of responding to a change in the modulation scheme used for wireless communication. The wireless communication device detects the occurrence of an unusable state for each of the plurality of channels. When the unusable state is detected, the current modulation scheme (64QAM) is changed to another modulation scheme (256QAM) that yields greater transmission capacity to secure the desired transmission capacity on the available channels.

Description

[Technical Field]

[0001] The present disclosure relates to a wireless communication system, a wireless communication method, and a wireless communication device, and more particularly to a wireless communication system, a wireless communication method, and a wireless communication device that are suitable for stably ensuring transmission capacity in a multiplex transmission system using multiple channels. [Background technology]

[0002] The following Patent Document 1 discloses a technology related to a virtual concatenation transmission system. More specifically, Patent Document 1 discloses a technology for constructing a highly flexible and efficient virtual concatenation group (VCG) by mixing multiple types of paths with different transmission speeds on a time division multiplexing line that performs synchronous transfer, such as an SDH (Synchronous Digital Hierarchy) / SONET (Synchronous Optical NETwork) network. [Prior art documents] [Patent documents]

[0003] Japanese Patent Application Publication No. 2007-13390 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a device that realizes large-capacity transmission by multiplexing multiple wireless channels as disclosed in Patent Document 1, if some channels become unusable due to radio interference or a malfunction, operation continues on the remaining channels, which results in a situation where operation has to continue on a bandwidth that is smaller than the bandwidth actually required.

[0005] If the necessary bandwidth cannot be secured, packet loss will occur in the excess bandwidth. If packet loss occurs, the quality of the services accommodated on the line cannot be secured, resulting in problems such as dropped calls in telephone services and distorted video in video services.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and has as its first object to provide a wireless communication system that can ensure a desired transmission capacity by multiplexing multiple wireless channels, and can stably ensure the desired transmission capacity even if some channels become unusable.

[0007] A second object of the present disclosure is to provide a wireless communication method that ensures a desired transmission capacity by multiplexing multiple wireless channels, and that stably ensures the desired transmission capacity even if some channels become unusable.

[0008] A third object of the present disclosure is to provide a wireless communication device that can ensure a desired transmission capacity by multiplexing multiple wireless channels, and can stably ensure the desired transmission capacity even if some channels become unusable. [Means for solving the problem]

[0009] In order to achieve the above object, a first aspect is a wireless communication system including a wireless communication device and a communication partner device that establish communication by multiplexing a plurality of channels, the wireless communication device and the communication partner device each have a function to accommodate a change in the modulation method used for wireless communication, The wireless communication device detecting an occurrence of an unavailable state for each of the plurality of channels; a method change process for changing the currently used modulation method to another modulation method that produces a larger transmission capacity when the unusable state is detected; and notifying the communication partner device of the change; It is desirable that the communication partner device be configured to change the modulation method to the other modulation method upon receiving the notification.

[0010] A second aspect is a wireless communication method using a wireless communication device and a communication partner device that establish communication by multiplexing a plurality of channels, the wireless communication device and the communication partner device each have a function to accommodate a change in the modulation method used for wireless communication, detecting an occurrence of an unavailable state for each of the plurality of channels; a method changing step of changing the currently used modulation method to another modulation method that produces a larger transmission capacity when the unusable state is detected; Sharing the changes between the wireless communication device and the peer device; It is desirable to include:

[0011] A third aspect is a wireless communication device that establishes communication with a communication partner device by multiplexing a plurality of channels, detecting an occurrence of an unavailable state for each of the plurality of channels; a method change process for changing the currently used modulation method to another modulation method that produces a larger transmission capacity when the unusable state is detected; a process of notifying the communication partner device of the change; Preferably, the system is configured to execute the following: [Effects of the Invention]

[0012] According to the first to third aspects, the transmission capacity secured by multiplexing a plurality of wireless channels can be stably secured even under circumstances where some channels become unusable. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram illustrating a characteristic operation of the wireless communication system according to the first embodiment of the present disclosure. [Figure 2] 1 is a block diagram illustrating a configuration of a wireless communication device used in a wireless communication system according to a first embodiment of the present disclosure. [Figure 3] 3 is a flowchart illustrating the flow of main processes executed in the wireless communication device shown in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0014] Embodiment 1 [Features of the first embodiment] FIG. 1 is a diagram illustrating features of a wireless communication system according to a first embodiment of the present disclosure. The upper area, separated by horizontal dashed lines, shows an image of multiple wireless channels that are expected to be used under normal circumstances. Hereinafter, these channels will be referred to as "working channels." Meanwhile, the lower area in FIG. 1 shows an image of backup channels that are not used under normal circumstances.

[0015] The image on the left side of Fig. 1 shows the basic state used in the wireless communication system of this embodiment. In the basic state, as shown in the figure, seven working channels and one backup channel are prepared. "64QAM (Quadrature Amplitude Modulation)" is used as the modulation method for the wireless signals, and each channel is given a transmission capacity of 150 Mbps. A transmission capacity of 1 Gbps is required for the wireless communication system of this embodiment, and this transmission capacity can be ensured by operating seven working channels.

[0016] The two crosses in the image on the top left of Figure 1 indicate that the corresponding channel has become unusable. This can occur, for example, due to a malfunction of the equipment transmitting the radio signal or interference in the frequency band used by those channels. In this case, if the five currently operating channels remain operational, the available transmission capacity will be 750Mbps, which does not meet the 1Gbps requirement.

[0017] The image in the center of Figure 1 shows the second state used in the wireless communication system of this embodiment to meet the 1 Gbps requirement under these circumstances. In this state, as shown in the figure, the modulation method is changed from "64QAM" to "256QAM." As a result, the transmission capacity of each of the five operational channels is increased to 200 Mbps, and the transmission capacity of the entire system meets the 1 Gbps requirement.

[0018] When a wireless communication system is operated with settings that maximize performance, performance may decrease in environments such as inclement weather, resulting in frequent changes in transmission capacity. Since it is desirable to minimize changes in the transmission capacity provided by the same communication service, it is desirable to ensure a certain degree of margin relative to the maximum setting allowed by the hardware. In this embodiment, such a marginal setting is used in the basic state. Therefore, in the second state, the modulation method can be changed to "256QAM," which can achieve higher performance, and the 1 Gbps requirement can be met even in an environment where two channels are unavailable.

[0019] In the second state shown in the center of Figure 1, if one more channel becomes unavailable, the number of active channels that can be operated will be reduced to four, and the 1 Gbps requirement will again not be met. The image on the right side of Figure 1 shows the third state that the wireless communication system of this embodiment adopts under such circumstances.

[0020] In the third state, a spare channel is used in addition to the four operational working channels. In the basic state, the spare channel is also assumed to be used at 150 Mbps, but in the third state, 256QAM is used as the modulation method, so its transmission capacity is 200 Mbps. As a result, the four working channels and one spare channel can meet the 1 Gbps requirement.

[0021] As explained above, the wireless communication system of this embodiment normally ensures a large transmission capacity by multiplexing a plurality of working channels. If some of the working channels become unusable, the system first changes the modulation method to ensure the desired transmission capacity using the operable working channels. If the desired capacity cannot be ensured using only the working channels, the system uses backup channels to ensure further capacity. As a result, this system can stably ensure the desired transmission capacity even if some channels become unusable.

[0022] [Configuration of the First Embodiment] 2 is a block diagram illustrating the configuration of a wireless communication device 10 used in the wireless communication system of this embodiment. The wireless communication device 10 has the function of transmitting large amounts of data simultaneously using multiple wireless channels. The configuration described below can be configured using electronic circuits made of dedicated hardware. Alternatively, the dedicated hardware may be combined with a memory storing a program and a processing unit, and some of the processing may be performed by having the processing unit execute the program.

[0023] The wireless communication device 10 includes an interface unit 12. The interface unit is connected to an opposing device (not shown). The wireless communication device 10 can transmit and receive information to and from the opposing device via a wired transmission path connected to the interface unit 12. The interface unit 12 includes a package switching unit 14, an interface board (current) 16, and an interface board (backup) 18.

[0024] The interface board (working) 16 has an interface for the working channels built in. For example, if seven working channels are prepared as shown in Figure 1, a corresponding interface is prepared for each of them.

[0025] The interface board (standby) 18 has an interface for the standby channel built in. As with the working channels, the interface board (standby) 18 is provided with interfaces in the same number as the number of standby channels. If there is only one standby channel as shown in Figure 1, the interface board (standby) 18 has one interface built in.

[0026] The PKG switching unit 14 is an element that switches between a working package and a backup package. Specifically, when some working channels become unusable, the PKG switching unit 14 appropriately switches the states of the interface board (working) 16 and the interface board (backup) 18 so that the working channels are replaced with backup channels.

[0027] The interface unit 12 is connected to a modulation / demodulation unit 20. The modulation / demodulation unit 20 includes a package switching unit 22, a modem (working) 24, and a modem (backup) 26. The package switching unit 22 switches between the modem (working) 24 and the modem (backup) 26 in conjunction with the package switching unit 14 of the interface unit 12. The modem (working) 24 modulates and demodulates signals transmitted using the working channel. On the other hand, the modem (backup) 26 modulates and demodulates signals transmitted using the backup channel.

[0028] The signal processed by the MODEM (working) 24 or the MODEM (backup) 26 is provided to an RF (Radio Frequency) unit 30. The RF unit 30 includes a package switching unit 32, a transceiver (working) 34, and a transceiver (backup) 36. The package switching unit 32 switches between the transceiver (working) 34 and the transceiver (backup) 36 in conjunction with the two package switching units 14 and 22. The transceiver (working) 34 and the transceiver (backup) 36 are both connected to antennas for transmitting and receiving radio signals. The transceiver (working) 34 performs processing necessary for transmitting and receiving radio signals on a working channel via an antenna. Meanwhile, the transceiver (backup) 36 performs similar processing for transmitting and receiving radio signals on a backup channel via an antenna.

[0029] The wireless communication device 10 of this embodiment further includes a monitoring control unit 40. The monitoring control unit 40 includes a monitoring unit 42. The monitoring unit 42 monitors the status of each of the interface unit 12, the modulation / demodulation unit 20, and the RF unit 30. If any of the multiple active channels becomes unusable due to a failure or interference, the monitoring unit 42 detects that status. If the monitoring unit 42 detects a failure or deterioration in communication quality, it provides that information to the control unit 44.

[0030] The control unit 44 includes a protection channel control unit 46 and a modulation format control unit 48. When the modulation format control unit 48 receives information from the monitoring unit 42 that a specific working channel is unavailable, it performs processing to change the modulation format to one that can provide higher performance than the current modulation format. If it is possible to change the modulation format, the modulation format control unit 48 issues a change request command to the MODEM (working) 24. As a result, for example, the format is changed from 64QAM to 256QAM, and the transmission capacity of each operable working channel is increased.

[0031] When the number of unavailable working channels is large and the desired transmission capacity cannot be secured by changing the modulation method, the spare channel control unit 46 sends a command to use the spare channels to the package switching units 14, 22, and 32. As a result, the third state described above in which the spare channels are used is realized, and the transmission capacity of the wireless communication device 10 is improved.

[0032] [Processing flow in the first embodiment] The flow of processing executed by the wireless communication device 10 of this embodiment will be described in more detail below with reference to Fig. 3. Fig. 3 is a flowchart for explaining the flow of main processing executed by the wireless communication device 10.

[0033] When any of the multiplexed working channels becomes unusable due to a failure or the like (step 100), the monitoring and control unit 40 detects the failure or quality degradation (step 102). In this case, the monitoring and control unit 40 first determines whether the modulation method can be increased from the current operating value (step 104).

[0034] If the modulation method is not at the upper limit, it can be determined that the modulation method can be changed. In this case, the monitoring control unit 40 next calculates the C / N value, which is the intensity ratio between the carrier wave and noise contained in the wireless signal received from the antenna (step 106).

[0035] For example, in order to change the modulation method to a faster (wider band) one, such as changing the modulation method from 64QAM to 256QAM, it is necessary to ensure a C / N ratio sufficient for obtaining sufficient communication quality with the changed modulation method. For this reason, the monitoring control unit 40 determines whether the current C / N ratio satisfies the required C / N ratio required for the changed modulation method (step 1 08 ).

[0036] If it is determined that the current C / N does not satisfy the required C / N, the monitoring control unit 40 then performs processing to improve the C / N value (step 110). Specifically, for example, the monitoring control unit 40 performs processing such as requesting the communication partner device, which is the source of the wireless signal, to increase its transmission power via the wireless transmission path. If the transmitting device increases the transmission power of the wireless signal in response to the request, the C / N is improved, and a situation can be created in which the required C / N is satisfied.

[0037] If it is determined in step 108 that the required C / N ratio is satisfied, and after issuing a request to improve the C / N ratio to satisfy the required C / N ratio in step 110, the monitoring control unit 40 executes modulation method switching control (step 112). Specifically, it requests the modem unit 20 to switch the modulation method.

[0038] In response to this, the modem unit 20 changes the modulation method so as to increase the transmission capacity. For example, the method is changed from 64QAM to 256QAM. Information regarding the change in modulation method is also notified to the other communication device that has established wireless communication with the wireless communication device 10 (step 114). In this way, if the C / N value can satisfy the required C / N, the wireless communication device 10 of this embodiment changes the modulation method to a faster (wider band) one, thereby improving the transmission speed per channel and compensating for the insufficient bandwidth due to the failure.

[0039] If a channel failure occurs (step 100) and the modulation method cannot be changed to a faster (wider) one (step 104), the wireless communication device 10 issues an instruction to switch the failed working channel to a backup channel (step 116). This instruction is provided to the interface unit 12, the modem unit 20, and the RF unit 30. As a result, the settings of the package switching units 14, 22, and 32 are switched, and information about this switching is notified to the other communication device in the wireless communication (steps 118, 120, and 122). As a result, a state in which the insufficient bandwidth is compensated for by the backup channel is realized. Note that, since using a backup channel requires equipment for the backup channel, in this embodiment, changing the modulation method is prioritized from the viewpoint of cost, and the backup channel is used as a second-best option.

[0040] As described above, according to the wireless communication system of this embodiment, when a failure or the like occurs in some of the multiple currently used channels, it is possible to appropriately adopt measures such as changing the modulation method, changing the modulation method after improving the C / N ratio, and using a backup channel. As a result, according to this system, it is possible to appropriately maintain the transmission bandwidth when a failure occurs in a multiplexed channel, and to stably guarantee the quality of communication services.

[0041] [Modification of the first embodiment] In the first embodiment described above, the wireless communication device 10 is connected to the opposing device, which is the source of information, via a wired transmission path, but the present disclosure is not limited to this. The wireless communication device 10 may also establish communication with the opposing device via a wireless transmission path multiplexed with multiple channels. In this case, the above-described methods for dealing with failures and the like may also be applied to the wireless transmission path between the opposing device and the wireless communication device 10.

[0042] In addition, in the above-described first embodiment, a backup channel is provided in the wireless transmission path, but the present disclosure is not limited to this. A failure or the like may be dealt with by simply changing the modulation method without providing a backup channel.

[0043] Furthermore, in the above-described first embodiment, the C / N ratio is improved before changing the modulation scheme, but improving the C / N ratio is not essential. It is also possible to not execute the process of improving the C / N ratio, and to change the modulation scheme only when the current C / N ratio satisfies the required C / N ratio, and to use a spare channel at that point in time when the required C / N ratio is not satisfied.

[0044] In the first embodiment described above, when a failure or the like of a working channel is detected, the C / N is calculated to determine whether or not the required C / N is ensured, but these processes are not essential. For example, the modulation method may be changed without calculating the C / N, on the premise that the required C / N can be satisfied.

[0045] Furthermore, in the first embodiment described above, after the process for improving the C / N is performed in step 110 shown in Fig. 3, the process for changing the modulation method is performed unconditionally in step 112. However, the present disclosure is not limited to this. For example, after performing step 110, the process of step 112 may be performed only if the required C / N is obtained, and if the required C / N is not obtained, the process may return to step 104 and change the policy to use the backup channel. [Explanation of symbols]

[0046] 10. Wireless communication devices 12 Interface section 20 Modulation and demodulation section 30 RF section 40 Monitoring and control section 42 Monitoring Department 44 Control Unit 46 Reserve channel control unit

Claims

1. A wireless communication system including a wireless communication device and a communication partner device that establishes communication by multiplexing a plurality of channels including a plurality of working channels that are expected to be used under normal circumstances, the wireless communication device and the communication partner device each have a function to accommodate a change in the modulation method used for wireless communication, The wireless communication device detecting an occurrence of an unavailable state for each of the plurality of working channels; a method change process for changing the modulation method currently used in the working channels to another modulation method that produces a larger transmission capacity while maintaining the bandwidth of each of the working channels when the unavailable state is detected; and notifying the communication partner device of the change; The wireless communication system is configured such that the communication partner device receives the notification and changes the modulation method to the other modulation method.

2. the plurality of channels includes, in addition to the plurality of working channels, at least one backup channel intended for backup use; The wireless communication device The use of the protection channel is not instructed while the current channel capacity, which is the sum of the transmission capacities of the available current channels, satisfies the desired transmission capacity by changing the modulation method; a process of determining whether it is possible to change the modulation scheme so as to achieve the current channel capacity that satisfies the desired transmission capacity; a process of instructing the use of the backup channel when the determination is negative; 10. The wireless communication system of claim 1, configured to execute:

3. The wireless communication device When the unusable state is detected, a C / N improvement process is performed to increase the C / N, which is the intensity ratio of a carrier wave to noise included in the wireless signal exchanged with the communication partner device; 3. The wireless communication system according to claim 1, wherein the method change process is executed after the C / N improvement process is executed.

4. The wireless communication device When the unusable state is detected, a process of calculating the current C / N achieved at that time; and determining whether the current C / N satisfies a required C / N required when using the other modulation method; 4. The wireless communication system according to claim 3, wherein the system is configured to execute the C / N improvement process when the current C / N does not satisfy the required C / N.

5. The wireless communication system according to claim 4, wherein the wireless communication device is configured to execute the method change process when a C / N that satisfies the required C / N is obtained as a result of the C / N improvement process.

6. The wireless communication device When the unusable state is detected, a process of calculating the current C / N achieved at that time; and determining whether the current C / N satisfies a required C / N required when using the other modulation method; 6. The wireless communication system according to claim 1, wherein the system change process is executed when the current C / N satisfies the required C / N.

7. A wireless communication method using a wireless communication device and a communication partner device to establish communication using multiple channels including multiple working channels that are expected to be used under normal circumstances, the wireless communication device and the communication partner device each have a function to accommodate a change in the modulation method used for wireless communication, detecting an occurrence of an unavailable state for each of the plurality of working channels; a method changing step of changing the modulation method currently used in the working channels to another modulation method that produces a larger transmission capacity while maintaining the bandwidth of each of the working channels when the unavailable state is detected; Sharing the changes between the wireless communication device and the peer device; A wireless communication method comprising:

8. A wireless communication device that establishes communication with a communication partner device by multiplexing a plurality of channels including a plurality of working channels that are expected to be used under normal circumstances, detecting an occurrence of an unavailable state for each of the plurality of working channels; a method change process for changing the modulation method currently used in the working channels to another modulation method that produces a larger transmission capacity while maintaining the bandwidth of each of the working channels when the unavailable state is detected; a process of notifying the communication partner device of the change; 10. A wireless communication device configured to:

Images