JP5897320B2 - Wireless communication system - Google Patents

Description

  The present invention relates to traffic control in an autonomous distributed wireless network.

  In recent years, autonomous distributed wireless networks, which are a type of wireless network, have been put into practical use. An autonomous decentralized wireless network refers to a wireless network that does not require an access point or a base station and is automatically constructed between nodes using a relay function of a wireless node (hereinafter referred to as a node). This corresponds to an ad hoc mode based on (Local Area Network). Each node in the autonomous distributed wireless network can perform direct wireless communication with an adjacent node and indirect wireless communication with a node farther than that (wireless communication via relay by another node).

An autonomous decentralized wireless network can form a wireless network without using access points and base stations used in the centralized control method, so it is possible to easily change the scale of the network by adding (or deleting) nodes. is there. Further, even when some nodes are down, the surrounding nodes automatically change the route, so that flexible operation against a failure is possible compared to the centralized control method.
On the other hand, since nodes are in an equal relationship in an autonomous distributed wireless network, QoS (Quality of Service) for guaranteeing service quality of various communications (voice communication, video communication, mail communication, etc.) ) Becomes more complicated, and the use efficiency of the radio line is lower than the centralized control method.

  In particular, when a CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) method is used as a wireless access method, each node calculates a random time called a random backoff after detecting a carrier stop of the wireless line, and the backoff time The data transmission timing is obtained after elapse. For this reason, depending on the calculation result of the back-off time at each node, communication data may collide with each other, which may require further waiting time, resulting in inefficient QoS control. .

FIG. 12 shows an example of communication by the conventional CSMA / CA method.
In the figure, after data transmission from the node A to the node B is completed, an ACK (Acknowledgement) signal is transmitted from the node B to the node A after the SIFS (Short Interface Space) time elapses, and then the DIFS ( The emergency data is transmitted from the node C after the elapse of the Distributed Interframe Space) time and the random backoff time.
As described above, in the conventional CSMA / CA method, even if the emergency data is transmitted from the node C while the data is being transmitted from the node A to the node B, the node C obtains an opportunity to use the radio line. Until it is completed (until a predetermined time elapses after the communication between the node A and the node B ends), the transmission of emergency data is awaited.

Various inventions have been proposed so far for handling emergency data in network communication.
For example, in Patent Document 1, in a token bus type local network system in which a plurality of data transmission devices are connected to a transmission path on a path to transmit a frame, an event of performing emergency communication from a plurality of data transmission devices occurs, When frames are still being transmitted on the transmission path, each frame is forcibly transmitted, causing a collision with a frame that is already being transmitted, interrupting the transmission, and interrupting emergency communications other than high priority emergency communications Thus, there has been disclosed an invention that enables an emergency communication to be executed at an early stage without waiting for reception of a token frame even when a plurality of emergency communications occur.

JP-A-3-55933

  An object of the present invention is to propose a technique capable of efficiently transmitting emergency data in a wireless communication system formed by a plurality of communication devices that perform wireless communication directly or indirectly with each other.

  The present invention has an emergency mode for restricting data that can be transmitted by a communication device in the wireless communication system to predetermined data in a wireless communication system formed by a plurality of communication devices that directly or indirectly wirelessly communicate with each other. Thus, the range in which the emergency mode is applied can be switched to the range in which the entire wireless communication system or the data transmission source communication device performs direct wireless communication.

As described above, in the present invention, the range to which the emergency mode is applied can be switched. Therefore, in the entire wireless communication system, emergency data that can be transmitted in the emergency mode (highly urgent data) and other normal data (emergency data) Data with low urgency compared to the above can be transmitted efficiently.
Here, as a typical example of a wireless communication system formed by a plurality of communication devices that directly or indirectly wirelessly communicate with each other, a wireless communication system using an autonomous distributed wireless network (also referred to as an ad hoc network) can be given. .

Here, as an example of the configuration, the data that can be transmitted in the emergency mode may be limited to a packet to which a multicast address or a broadcast address is added. Thus, by making it possible to limit data that can be transmitted in the emergency mode to packets that need to be widely transmitted, highly urgent information can be efficiently transmitted to the network.
In addition, when the range to which the emergency mode is applied is the entire wireless communication system, it is more effective to limit the data that can be transmitted in the emergency mode to a packet to which a multicast address or a broadcast address is added. .
Furthermore, when a packet to which an address other than a multicast address or a broadcast address is added is transmitted in the emergency mode, it may be configured to notify that transmission is not possible. You can encourage them to re-send.

Further, as one configuration example, data that can be transmitted in the emergency mode may be configured to be limited to packets to which a specific transmission destination address is added. Thus, by making it possible to limit the transmission destination to a specific partner, highly urgent information can be efficiently transmitted to a partner who needs it.
Further, when a packet to which an address other than a specific destination address is added is transmitted in the emergency mode, it may be configured to notify that transmission is not possible. You can encourage them to re-send.

  According to the present invention, emergency data can be efficiently transmitted in a wireless communication system formed by a plurality of communication devices that perform wireless communication directly or indirectly with each other.

It is a figure which shows the example of a node structure in the autonomous distributed radio | wireless network which concerns on one Embodiment of this invention. It is a figure which shows a mode that only the emergency access category was permitted transmission in the node structure of this example. It is a figure which shows the example of the block configuration of the node which forms the autonomous distributed wireless network of this example. It is a figure which shows the example of the message which flows between blocks in the data transmission origin node of this example. It is a figure which shows the example of the message which flows between blocks in the data receiving node of this example. It is a figure which shows the example of the transmission flow in the emergency mode process part of this example. It is a figure which shows the example of the reception flow in the emergency mode process part of this example. It is a figure which shows the example of the information produced | generated or added in the emergency mode process part of this example. It is a figure which shows the example of the communication restriction | limiting by the control frame in this example. It is a figure which shows the example of collision generation using the error signal in this example. It is a figure which shows the example of control of the back-off time in this example. It is a figure which shows the example of the communication by the conventional CSMA / CA system.

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an example of a node configuration in a wireless communication system of an autonomous distributed wireless network (appropriately abbreviated as wireless network) according to an embodiment of the present invention.
In the wireless communication system of FIG. 1, a wireless network is formed by five nodes A, B, C, D, and E. Each node is composed of a communication device having a function of performing wireless communication and its relay, and by establishing and maintaining a wireless link with each adjacent node, each node can communicate with each other via the wireless link. Wireless communication is possible. For example, the node A can perform direct wireless communication with the adjacent nodes B and C and indirectly perform wireless communication with the non-adjacent node D via (relay) the node B or the node C depending on the situation. Yes.

In an autonomous distributed wireless network, an indirect wireless communication path via another node is autonomous by exchanging control messages such as an OLSR (Optimized Link State Routing) protocol Hello message or a TC (Topology Control) message. Built in. That is, by periodically exchanging control messages between nodes, the node configuration of the wireless network is grasped, and a communication path according to the current node configuration is set. For this reason, even when a change in node configuration (new participation or withdrawal of a node) occurs, the communication path can be autonomously changed according to the changed node configuration.
For example, in a case where the node A is configured to perform wireless communication with the node D via the node B, when the node B leaves the wireless network due to the stop or movement of the node B, the node A is adjacent to the other The route setting is switched so as to perform wireless communication with the node D via the node C.

The information flowing between the radio links is classified into one of a plurality of access categories such as voice and video by using a method called EDCA (Enhanced Distributed Channel Access), and the transmission order is controlled. In EDCA, different priority is assigned to each access category, and an access category having a higher priority has a shorter waiting time until a data transmission right is obtained than an access category having a lower priority.
Further, as shown in FIG. 1, the information flowing between the radio links can be divided into emergency data that is information with a high degree of urgency, or normal data that is information with a lower degree of urgency than the emergency data. Here, since emergency data is required to be transmitted quickly, a device for preferentially transmitting emergency data is required.

  Here, in this example, data belonging to a predetermined access category (hereinafter referred to as an emergency access category) is handled as emergency data. For example, when voice data such as emergency broadcast voice is used as emergency data, a voice access category may be used as the emergency access category. Which access category is set as the emergency access category may be set in advance, or may be designated at any time by the user when transmitting emergency data.

  Note that all data belonging to the emergency access category may be handled as emergency data, or may be handled as emergency data by satisfying other requirements. Other requirements related to the emergency data include, for example, requirements related to the destination address. Specifically, when the data belongs to the emergency access category and the transmission destination address is multicast or broadcast, or when the data is a specific address set in advance as a transmission destination of emergency data, the data Is treated as emergency data. Moreover, you may make it receive from the user the explicit designation | designated that it is emergency data.

FIG. 2 shows a state where transmission is permitted only in the emergency access category in the node configuration of this example.
In the figure, node C broadcasts a control frame specifying an emergency access category to adjacent nodes (nodes A, B, D, and E) prior to transmission of emergency data. Each adjacent node that has received this control frame permits communication only for data in the emergency access category specified by the control frame. As a result, data in other access categories is discarded at the transmission source node and the relay node. As a result, as shown in FIG. 2, a wireless network in which only emergency access category data flows on the wireless link can be constructed, and the node C can quickly transmit emergency data.
In this example, the state in which data transmission is restricted to data in the emergency access category only, that is, the state in which normal data transmission is prohibited is referred to as the emergency mode, and the state in which normal data transmission is permitted is referred to as the normal mode. That's it.
In this example, when it is determined that the data scheduled to be transmitted is emergency data, the emergency mode is automatically switched. However, the emergency mode is set in response to the user's designation to switch to the emergency mode. You may make it switch to.

  Here, the control frame may be notified only to the adjacent node of the transmission source node, or may be relayed to the entire network via the adjacent node, and can be switched at the transmission source node (emergency data transmission source node). is there. In other words, the range to which the emergency mode is applied is limited to only the adjacent node of the transmission source node (a range in which the transmission source node can perform direct wireless communication), or the entire network of the wireless communication system (the transmission source node is directly or indirectly wireless). The range within which communication can be performed) can be selected (specified) at the source node. In the application range of the emergency mode (the range in which the control frame is transmitted), data transmission is permitted only for the emergency access category, and data transmission for other access categories is prohibited.

  For this reason, for example, emergency data that a person (user) who wants to transmit emergency data needs to transmit to at least the adjacent nodes quickly or needs to be transmitted quickly to the entire network Depending on the situation, it is possible to operate the communication device that is the emergency data transmission source node and input the designation of the application range of the emergency mode. The emergency mode coverage is set. In this way, by appropriately setting the application range of the emergency mode according to the situation, it is possible to suppress the unauthorized transmission of normal data while realizing the rapid transmission of emergency data. Emergency data and normal data can be transmitted efficiently.

FIG. 3 shows an example of a block configuration of nodes forming the autonomous distributed wireless network of this example.
In this example, the network processing unit 1 is arranged in the network layer, the QoS control unit 2, the emergency mode processing unit 3, the timer 4, the error signal generation unit 5, and the CSMA / CA unit 6 are arranged in the data link control layer. The radio signal processing unit 7 is arranged in the layer.

  In addition, an application unit is arranged above the network layer. In the application unit, an operation input unit (not shown) receives input of application data (normal data and emergency data) to be transmitted to another node and information such as a transmission destination from the user of the own node. The application unit outputs application data received from another node in the wireless network in a mode corresponding to the data format by an output unit (not shown). For example, audio access category data is output as audio, and video access category data is output as video.

The network processing unit 1 exchanges data between the application unit and the QoS control unit 2.
The QoS control unit 2 classifies the application data transferred from the network processing unit 1 into access categories.
When the data from the QoS control unit 2 (transmission data to another node) belongs to the emergency access category, the emergency mode processing unit 3 transmits a control frame using this as a trigger, and then transmits emergency data. . When the data from the CSMA / CA unit 6 (received data from another node) is a control frame (or emergency data with a backoff time coefficient added), the timer unit 4 (or CSMA / CA unit 6). To control. Details of the control will be described later.
The timer unit 4 manages the duration of the emergency mode (a wireless network that allows data transmission only in the emergency access category).
The error signal generation unit 5 causes a reception error on the receiving node side by causing a data collision on the wireless line.
The CSMA / CA unit 6 performs CSMA / CA processing. As CSMA / CA processing, adjustment of back-off time (data transmission waiting time) is performed.
The wireless signal processing unit 7 transmits and receives wireless signals.

FIG. 4 shows an example of messages flowing between blocks in the data transmission source node of this example.
The network processing unit 1 packetizes application data (normal data or emergency data) input from an upper layer application unit and outputs the packetized data to the QoS control unit 2.
The QoS control unit 2 stores a packet of application data input from the network processing unit 1 in a frame and outputs it to the emergency mode processing unit 3. In addition, information on the access category of application data is also output.
The emergency mode processing unit 3 outputs the application data frame (data frame) input from the QoS control unit 2 to the CSMA / CA unit 6. Further, when the application data is emergency data (in the case of belonging to the emergency access category), if the mode at that time is the normal mode, the mode is switched to the emergency mode, and the emergency access category and the duration of the emergency mode are further switched. A control frame (control frame) including the above information is output to the CSMA / CA unit 6. When outputting emergency data, a backoff time coefficient for adjusting the backoff time on the receiving node side may be added (for example, stored in a data frame of emergency data) and transmitted.
The error signal generation unit 5 outputs an error signal to the CSMA / CA unit 6 before frame transmission based on the transmission timing information of the control frame (or data frame of emergency data) notified from the emergency mode processing unit 3.
The CSMA / CA unit 6 outputs the frame (data frame or control frame) input from the emergency mode processing unit 3 or the error signal input from the error signal generation unit 5 to the radio signal processing unit 7.
The radio signal processing unit 7 converts the frame (data frame or control frame) or error signal input from the CSMA / CA unit 6 into a radio signal and sends it to the radio line.

FIG. 5 shows an example of messages flowing between blocks in the data receiving node of this example.
The radio signal processing unit 7 restores a frame (data frame or control frame) or an error signal from the radio signal received from the radio line and outputs it to the CSMA / CA unit 6.
The CSMA / CA unit 6 outputs the frame (data frame or control frame) input from the radio signal processing unit 7 to the emergency mode processing unit 3. When an error signal is input from the wireless signal processing unit 7 during communication with another node, it is determined that a reception error has occurred in communication with the other node, and communication is interrupted. The interruption time (waiting time until communication restarts) is adjusted by a back-off time coefficient from the emergency mode processing unit 3 or the like.
The emergency mode processing unit 3 outputs the data frame input from the CSMA / CA unit 6 to the QoS control unit 2. Further, when a control frame is input from the CSMA / CA unit 6, switching to the emergency mode is performed based on the control frame. Further, when a backoff time coefficient or the like is added to the emergency data received in the emergency mode (for example, stored in the data frame of the emergency data), this additional information is output to the CSMA / CA unit 6.
The QoS control unit 2 extracts a packet of application data (normal data or emergency data) from the data frame input from the emergency mode processing unit 3 and outputs the packet to the network processing unit 1.
The network processing unit 1 restores the application data from the packet of application data input from the QoS control unit 2 and outputs it to the upper layer application unit.

In FIG. 6, the example of the transmission flow in the emergency mode process part 4 of this example is shown.
It is determined whether or not the access category of the application data to be transmitted is an emergency access category (step S1). If the access category is not an emergency access category, the data is discarded (step S8).
If the access category of the application data to be transmitted is the emergency access category, the timer unit 4 is confirmed (step S2).
As a result of checking the timer unit 4, if the duration of the emergency mode has timed out, carrier sense is performed (step S3), and if a carrier is detected on the wireless line, an error signal generating unit 5 is detected. Is instructed to transmit an error signal (step S7). After that, the duration of the emergency mode is set for the timer unit 4 (step S4), and the control frame specifying the emergency access category and the duration of the emergency mode set in the timer unit 4 is transmitted (step 5). Then, emergency data is transmitted (step S6).
As a result of checking the timer unit 4, if the duration of the emergency mode is being counted, since the own node or another node has already transmitted the control frame, the emergency data can be transmitted without transmitting the control frame again. It performs (step S6).

FIG. 7 shows an example of a reception flow in the emergency mode processing unit 4 of this example.
The frame type of the received frame is determined (step S21), and if it is a control frame, the duration of the emergency mode specified in the control frame is set in the timer unit 4 (step S28), and the control frame Is set to the emergency access category specified in step S29 (step S29) to switch to the emergency mode. Further, based on the destination of the control frame or the setting contents thereof, the control frame is further relayed to the adjacent node as necessary (step S30).
When the received frame is a data frame (normal data frame or emergency data frame), the timer unit 4 is checked (step S22).
As a result of checking the timer unit 4, if the duration time of the emergency mode is up, normal data reception processing is performed (step S27).
On the other hand, as a result of checking the timer unit 4, if the duration of the emergency mode is being counted, the frame type is confirmed again (step S23), and if it is a normal data frame, the data is discarded ( In step S26), in the case of an emergency data frame, normal data reception processing is performed (step S27). If a backoff time coefficient or the like is stored in the emergency data frame, the information may be used to adjust the backoff time of the own node (step S24).

FIG. 8 shows an example of information generated or added by the emergency mode processing unit 4 of this example. Note that the setting contents illustrated in FIG. 8 are held (stored) in the memory of each node (communication device).
As shown in FIG. 8A, as the control frame, for example, a control frame including information on access category, packet destination type, and duration corresponding to emergency data is used. In FIG. 8A, “Category 1 (Voice)” is set as the access category, “Multicast” is set as the packet destination type, and “10 seconds” is set as the duration. , “Allow multicast Voice communication for 10 seconds”. If a control frame in which such information is set is used, data that can be transmitted in the emergency mode can be limited to packets that need to be widely transmitted. The same effect can be obtained by using a broadcast packet instead of the multicast packet.

Here, depending on whether the application range of the emergency mode is only the adjacent node or the entire network, whether to limit the data that can be transmitted in the emergency mode to only multicast (or broadcast) packets is changed. It may be. In particular, when the application range of the emergency mode is the entire network, highly urgent information is efficiently transmitted to the network by limiting the data that can be transmitted in the emergency mode to only multicast (or broadcast) packets. be able to.
In this case, by providing a notification unit for notifying that transmission is not possible when a packet to which an address other than a multicast (or broadcast) packet is added is transmitted, the user (the sender of the packet) ) Can be urged to retransmit with an appropriate address. The notification that transmission is not possible can be performed by various methods, for example, a method for displaying a message indicating that transmission is not possible, a method for outputting a sound indicating that transmission is not possible, etc. Is mentioned.

Further, instead of a configuration in which data that can be transmitted in the emergency mode is limited to only multicast (or broadcast) packets, data that can be transmitted in the emergency mode is limited to only packets to which a specific destination address is added. May be. Thereby, highly urgent information can be efficiently transmitted to an organization or a person who is required to take an emergency response such as a fire department.
In this case, by providing a notification unit for notifying that transmission is not possible when a packet to which an address other than a specific destination address is added is about to be transmitted, the user (the sender of the packet) is provided. You can encourage re-sending with the right address. The notification that transmission is not possible can be performed by various methods, for example, a method for displaying a message indicating that transmission is not possible, a method for outputting a sound indicating that transmission is not possible, etc. Is mentioned.

In addition to the control frame, information may be added to the emergency data itself to interfere with the operation of the receiving node.
As shown in FIG. 8B, as information added to the emergency data, for example, information on a back-off time coefficient and a duration for increasing or decreasing the back-off time is used. In FIG. 8B, “2” is set as the back-off time coefficient and “20 seconds” is set as the duration, and these setting contents are “double the back-off time for 20 seconds”. "Means. If the emergency data to which such information is added is used, the subsequent emergency data can be preferentially transmitted by the transmission source node.

FIG. 9 shows an example of communication restriction by the control frame in this example.
The node C that intends to transmit emergency data performs carrier sense and confirms that there is no carrier on the radio line, and then specifies the emergency access category corresponding to the emergency data and the duration of the emergency mode. Send. As a result, only the emergency access category is communicable during the duration of the emergency mode, so that the node C can promptly transmit emergency data.

FIG. 10 shows an example of collision occurrence using an error signal in this example.
When the carrier C detects that the carrier C is detected as a result of performing carrier sense, the node C that intends to transmit emergency data transmits an error signal prior to transmission of the control frame. The error signal is preferably a signal having a pilot signal portion other than a predetermined pattern, as long as a radio error of one symbol or more is generated. In this example, an error signal is transmitted during data transmission from the node A to the node B. As a result, a radio error occurs in the node B, so the node B does not make an ACK response. For this reason, the node C can transmit the control frame at the timing when the ACK response by the node B is implemented. Therefore, it is possible to reliably transmit the control frame after transmitting the error signal. Note that the data transmission from the node A to the node B interrupted by the transmission of the error signal is resumed along with the return to the normal mode due to the elapse of the continuation time of the emergency mode, and the data being transmitted is retransmitted.

  In the emergency mode, data can be transmitted even if it is data other than the transmission source node of the control frame as long as the data belongs to the emergency access category. Here, in order for the control frame transmission source node to transmit emergency data preferentially over other nodes, the information (backoff time coefficient and the information shown in FIG. By adding (continuation time information) to the emergency data, the back-off time in the nodes other than the control frame transmission source node may be adjusted. Thereby, the transmission source node of the control frame can transmit emergency data with priority over other nodes.

  Further, as shown in the example of the control of the back-off time in FIG. 11, the transmission of the control frame can be omitted. That is, the node C that is to transmit emergency data transmits an error signal before transmitting the emergency data, so that the emergency data is reliably transmitted after the error signal is transmitted. By adding the coefficient and the duration information, the subsequent emergency data can be transmitted with priority over other nodes.

  As described above, according to the present invention, the emergency data transmission source node transmits the control frame designating the emergency access category corresponding to the emergency data to the other node before the emergency data is transmitted. Switch to emergency mode that restricts data transmission to categories only. As a result, data in an access category other than the emergency access category is discarded, and emergency data can be transmitted with priority.

  In addition, by enabling an emergency data transmission source node to select an adjacent node or the entire network as a control frame transmission destination, the application range of the emergency data can be switched to the adjacent node or the entire wireless network. Thus, by appropriately setting the application range of the emergency mode according to the situation, it is possible to suppress the unauthorized transmission of normal data while realizing the rapid transmission of emergency data, Emergency data and normal data can be transmitted efficiently.

  Also, the emergency mode is maintained at the emergency data transmission source node, and the emergency mode is continued only during the maintenance time by transmitting the control frame specifying the maintenance time. Thereby, it is possible to automatically return to the normal mode after the maintenance time has elapsed.

  In addition, by transmitting and generating an error signal before transmitting a control frame (or emergency data) at the emergency data transmission source node, a radio error is detected at another node already in communication. Thereby, communication of other nodes can be interrupted and a control frame (or emergency data) can be transmitted reliably.

  In addition, the emergency data transmission source node adds a back-off time coefficient (and its maintenance time) for increasing the back-off time to the emergency data for transmission. As a result, the back-off time is increased at the emergency data receiving node, so that the emergency data transmission source node can preferentially transmit the subsequent emergency data.

Further, in the present invention, the emergency data transmission destination address is taken into consideration when the emergency mode is applied.
That is, the data that can be transmitted in the emergency mode is limited to packets to which a multicast address or a broadcast address is added. As a result, data that can be transmitted in the emergency mode is limited to packets that need to be widely transmitted, so that highly urgent information can be efficiently transmitted to the network.
Here, when the application range of the emergency mode is the entire network, it is more effective if the data that can be transmitted in the emergency mode is limited to packets to which a multicast address or a broadcast address is added. Furthermore, when a packet to which an address other than a multicast address or broadcast address is added is transmitted in the emergency mode, it is configured to notify the sender that the transmission is impossible, so that an appropriate address can be sent to the sender. You can encourage them to retransmit.

Note that data that can be transmitted in the emergency mode is not limited to a packet to which a multicast address or a broadcast address is added, but may be limited to only a packet to which a specific destination address is added. Thereby, highly urgent information can be efficiently transmitted to an organization or a person such as a fire department that requires emergency response.
Here, when a packet to which an address other than a specific destination address is added is transmitted in the emergency mode, an appropriate address is transmitted to the sender by notifying that transmission is impossible. You can encourage them to re-send.

The present invention can also be understood as the following wireless communication apparatus.
That is, the wireless communication device according to the present invention is a node that forms an autonomous distributed wireless network, a QoS control unit that prioritizes normal data and emergency data according to an access category, and an emergency data access category ( An emergency mode processing unit for transmitting control information (control frame) including information of emergency access category) to an adjacent node (another wireless communication apparatus capable of direct wireless communication), and the adjacent node before transmitting emergency data A wireless network dedicated to emergency data is formed by sending control information to and notifying an emergency access category. Furthermore, the emergency mode processing unit includes the time information for maintaining the radio network dedicated to emergency data in the control information and notifies the adjacent node, so that the local node and the adjacent node can be identified after the designated time (maintenance time) has elapsed. , And returning to a normal state without designation of an access category that can be used for data transmission.
A wireless communication device according to the present invention is a node that forms a CSMA / CA autonomous distributed wireless network, a QoS control unit that determines the presence or absence of highly urgent emergency data and adjusts transmission timing; An error signal generation unit that generates an error signal that generates a radio error of one symbol or more in radio, and an additional information processing unit (emergency mode processing unit) that transmits emergency data with a random backoff coefficient and its maintenance time added thereto A backoff time changing unit (CSMA / CA unit) that changes the random backoff time of its own node based on the random backoff coefficient added to the received emergency data and the maintenance time thereof, and at the time of transmitting the emergency data Control while generating error signal and waiting for longer than SIFS time for neighboring node to send ACK signal response It is possible to transmit emergency data reliably by transmitting traffic frames (or emergency data) and temporarily suppressing traffic of neighboring nodes by a random backoff coefficient and maintenance time added to the emergency data. And

Here, the configuration of the system and apparatus according to the present invention is not necessarily limited to the configuration described above, and various configurations may be used. The present invention can also be provided as, for example, a method or method for executing the processing according to the present invention, a program for realizing such a method or method, or a recording medium for recording the program. It is also possible to provide various systems and devices.
The application field of the present invention is not necessarily limited to the above-described fields, and the present invention can be applied to various fields.
In addition, as various processes performed in the system and apparatus according to the present invention, for example, the processor executes a control program stored in a ROM (Read Only Memory) in hardware resources including a processor and a memory. A controlled configuration may be used, and for example, each functional unit for executing the processing may be configured as an independent hardware circuit.
The present invention can also be understood as a computer-readable recording medium such as a floppy (registered trademark) disk or a CD (Compact Disc) -ROM storing the control program, and the program (itself). The processing according to the present invention can be performed by inputting the program from the recording medium to the computer and causing the processor to execute the program.

  1: network processing unit, 2: QoS control unit, 3: emergency mode processing unit, 4: timer, 5: error signal generation unit, 6: CSMA / CA unit, 7: radio signal processing unit

Claims (6)

In a wireless communication system using an autonomous distributed wireless network formed by a plurality of communication devices that directly or indirectly wirelessly communicate with each other,
Each of the plurality of communication devices includes a network processing unit arranged in a network layer, a QoS control unit arranged in a data link control layer, an emergency mode processing unit, a timer, an error signal generation unit, a CSMA / CA unit, A wireless signal processing unit arranged in the physical layer,
In the communication device that is the data transmission source, the QoS control unit classifies the data to be transmitted into one of a plurality of access categories, and the emergency mode processing unit, when the data belongs to a predetermined access category, Transmitting a control frame instructing application of an emergency mode in which data that can be transmitted by a communication device in the wireless communication system is limited to predetermined data ;
Further, the communication device serving as the data transmission source accepts a designation as to whether or not the range in which the emergency mode is applied is limited to a range in which the communication device performs direct wireless communication by a user operation, and the communication device according to the designation Send control frames,
A wireless communication system. The wireless communication system according to claim 1, wherein
Data that can be sent in emergency mode can be limited to packets with a multicast address or broadcast address added.
A wireless communication system. The wireless communication system according to claim 2,
When the range in which the emergency mode is applied is not limited to the range in which the communication device that is the data transmission source performs direct wireless communication, the data that can be transmitted in the emergency mode is included in a packet to which a multicast address or a broadcast address is added. Restrict,
A wireless communication system. The wireless communication system according to claim 1, wherein
Data that can be sent in emergency mode can be limited to packets with a specific destination address.
A wireless communication system. The wireless communication system according to claim 2 or claim 3,
Notifying that transmission is not possible when a packet to which an address other than a multicast address or a broadcast address is added is transmitted in the emergency mode,
A wireless communication system. The wireless communication system according to claim 4, wherein
Notifying that transmission is not possible when a packet to which an address other than a specific destination address is added in the emergency mode is about to be transmitted,
A wireless communication system.

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