JP2008148029A - Radio communication system and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the overlap of all addresses in a system with an inexpensive configuration. <P>SOLUTION: One's own identification information is added to an address assigned to oneself for regularly sending from a router 20 and an end device 30 to a coordinator 10. In the coordinator 10, the address sent from the router 20 and the end device 30 corresponds to the identification information added to the address for writing in an address table TA for detecting overlap. When the sent address has already been written into the address table TA for detecting overlap, the identification information in the table TA corresponding to the address is compared with that added to the sent address. When both the pieces of identification information differ, the sent address is detected as an overlap address. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a radio communication system having a tree structure and a device used in the radio communication system.

  In recent years, systems that perform environmental measurement, monitoring, control, and the like using wireless communication are increasing. In a wireless communication system that performs environmental measurement, monitoring, control, and the like, there are many cases where the target area is relatively wide or there are many obstacles for wireless communication in the target area. In such a case, in order to cover the target area, even if it is not possible to communicate directly depending on the environment such as the installation position of the receiver and the transmitter and the radio wave condition, it is possible to perform communication by relaying other devices. It is advantageous to use a communication network.

  As this type of wireless communication network, a wireless communication network using a Zigbee (registered trademark) protocol is considered (for example, see Patent Document 1 and Patent Document 2). Hereinafter, a wireless communication network using the ZigBee protocol is referred to as a ZigBee network.

The ZigBee network is a tree-structured wireless communication network, and is composed of the following three types of devices.
[Device A (Node A)]
It is called a coordinator and exists only in the base layer (top layer) of the network, can communicate with lower-level devices, commands all devices in the network, and is sent from each device-specific information and each device. Supervise the collection of information. In addition to acting as a general master station for the entire network, it also assigns addresses to devices that have a parent-child relationship with itself.

[Device B (Node B)]
It is called a router and exists below the coordinator. It can communicate with upper devices and lower devices, receives commands from the coordinator, and can connect lower devices (routers or end devices) to these devices. On the other hand, it plays the role of a local master station. Also, addresses are assigned to devices that have a parent-child relationship with themselves.

[Device C (Node C)]
It is called an end device, exists at the end (lowest level) of the network, can communicate with a higher level device, and does not become a master station of other devices. For example, in an air conditioning control system, a sensor such as a temperature sensor or a humidity sensor is an end device.

  For each device of the ZigBee network, the maximum number Cm of lower devices that can be connected and the lowest depth Lm of the hierarchy of the tree structure are determined as network parameters.

  FIG. 13 shows a simple example of a ZigBee network. In the figure, 1 is a coordinator located at the highest level (0th layer), 2-1 and 2-2 are routers located at the lower layer (first layer) of coordinator 1, 3-1, 3-2 and 3- 3 and 3-4 are end devices located in the lower layer (second layer (lowest layer)) of the routers 2-1 and 2-2.

  In this example, the identification number of the coordinator 1 is # 0, the identification numbers of the routers 2-1 and 2-2 are # 1 and # 2, and the identification numbers of the end devices 3-1 to 3-4 are # 3 to #. It is assumed that 6 is set. These identification numbers # 0 to # 6 are uniquely determined for each device and do not change. In this ZigBee network, the coordinator 1 is defined with address blocks AD0 to AD6 as addresses that can be assigned to the entire network, and “AD0” of these address blocks is assigned as its own address. .

  When connecting the router 2-1 to the coordinator 1, the router 2-1 is brought close to the coordinator 1 and the power is turned on. Then, a connection request called “association (participation application)” (hereinafter referred to as “associate connection request”) is sent from the router 2-1 to the coordinator 1. In response to the associate connection request from the router 2-1, the coordinator 1 assigns the address AD1 to the router 2-1, and also identifies the identification number # 1 of the router 2-1 and the address AD1 assigned to the router 2-1. Are stored in the connection information table T0 as having a parent-child relationship (“◯”). Further, address blocks “AD1 to AD3” including the address AD1 are sent to the router 2-1 as addresses that can be assigned to lower devices.

  Next, when the router 2-2 is brought close to the coordinator 1 and the power is turned on, an associate connection request is sent from the router 2-2 to the coordinator 1. Upon receiving the associate connection request from the router 2-2, the coordinator 1 assigns the address AD4 to the router 2-2, and also assigns the identification number # 2 of the router 2-2 and the address AD4 assigned to the router 2-2. Are written in the connection information table T0 as having a parent-child relationship. Also, the address block “AD4 to AD6” including the address AD4 is sent to the router 2-2 as an address that can be assigned to a lower device.

  When the end device 3-1 is brought close to the router 2-1 and the power is turned on, an associate connection request is sent from the end device 3-1 to the router 2-1. The router 2-1 receives the associate connection request from the end device 3-1, assigns the address AD 2 to the end device 3-1, and identifies the identification number # 3 of the end device 3-1 and the end device 3-1. The address AD2 assigned to is associated and written in the connection information table T1 as having a parent-child relationship.

  When the end device 3-2 is brought close to the router 2-1 and the power is turned on, an associate connection request is sent from the end device 3-2 to the router 2-1. The router 2-1 receives the associate connection request from the end device 3-2, assigns the address AD 3 to the end device 3-2, and identifies the end device 3-2 identification number # 4 and the end device 3-2. The address AD3 assigned to is associated and written in the connection information table T1 as having a parent-child relationship. Similarly, an address is assigned to each device.

  In this ZigBee network, for example, when the power of the end device 3-1 is turned off, the address AD2 assigned to the end device 3-1 disappears. In this case, when the power is turned on and restarted, a connection request called orphan (hereinafter referred to as orphan connection request) is sent from the end device 3-1 to the router 2-1 and stored in the router 2-1. The address AD2 corresponding to the identification number # 3 of the end device 3-1 in the connection information table T1 is read out and reassigned to the end device 3-1.

  Further, in this ZigBee network, for example, when a radio wave interference or the like occurs in the transmission path between the end device 3-1 and the router 2-1, information from the end device 3-1 (for example, temperature measurement value, humidity measurement) Value) cannot be received by the router 2-1. In this case, if the end device 3-1 is manually placed and the router 2-2 is within the transmission range, a new parent-child relationship is established between the router 2-2 and the end device 3-1, and the end device 3-1 Information is sent to the router 2-2, and the information is sent to a higher-level device. As a result, a new communication path is defined, and information from the end device 3-1 is continuously sent to the coordinator 1.

  Although a simple example is shown in FIG. 13, there are actually several layers of routers 2 between the highest level coordinator 1 and the lowest level end device 3, and the number of routers 2 and end The number of devices 3 also increases, and the network is large.

JP 2006-5928 A JP 2006-42370 A Japanese Patent Laid-Open No. 2005-64848 JP 2005-204016 A

  However, in the ZigBee network described above, after the router 2 assigns an address to a lower device, the connection information table T1 in the router 2 may be lost due to a failure or the like. Here, when a new device requests a parent-child connection to the router 2 in which the connection information table T1 has been lost, there is a possibility that an already assigned address is duplicated and assigned to the device that has obtained the parent-child connection. .

  For example, as shown in FIG. 14A, the connection information table T1 of the router 2-1 has a parent-child relationship with the end device 3-1, but the parent-child with the end device 3-2. The relationship has not yet been established. Here, it is assumed that the connection information table T1 in the router 2-1 is lost due to some abnormality (FIG. 14B), and the parent-child relationship between the router 2-1 and the end device 3-1 is lost. In this state, for example, when the end device 3-2 is brought close to the router 2-1 and the power is turned on (FIG. 14C), an associate connection request is sent from the end device 3-2 to the router 2-1. A parent-child relationship is established with the router 2-1.

  In this case, the router 2-1 determines that the addresses AD2 and AD3 remain as addresses that can be assigned to the lower device, assigns the address AD2 to the end device 3-2, and also assigns the end device 3- 2 is associated with the address AD2 assigned to the end device 3-2 and written in the connection information table T1 as having a parent-child relationship.

  For this reason, the address of the end device 3-1 and the address of the end device 3-2 become the same address AD <b> 2, duplication of addresses occurs, and information to the coordinator 1 is confused. Such address duplication may occur in the same way between the routers 2-1 and 2-2.

  Although it is not a ZigBee network, Patent Documents 3 and 4 disclose techniques for solving the address duplication problem. In these patent documents, a duplicate address detection function is provided inside a device that can be freely connected to another device. When this technology is applied to the above-described ZigBee network, a duplicate address detection function is added to all devices, resulting in a very expensive system.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a wireless communication system capable of detecting duplication of all addresses in the system with an inexpensive configuration. There is.

  In order to achieve such an object, the first invention (the invention according to claim 1) includes a first device located at the highest level and an address assigned to the own memory located at the lowest level. In a tree-structured wireless communication system including at least a second device to be stored, the second device is periodically transmitted to the first device by adding its own identification information to an address assigned to the second device. Means for storing the address transmitted from the second device in the memory in association with the identification information added to the address, and transmitted from the second device. When the address is already stored in the memory, the identification information stored corresponding to the address is compared with the identification information added to the transmitted address. If is different, it is provided with a means for detecting the address transmitted as a duplicate address.

  According to the first aspect of the invention, for example, when a wireless communication system having a two-layer tree structure in which the first device is a coordinator and the second device is a router or an end device, the router or the end device sends a self- The address assigned to is periodically transmitted with its own identification information. When an address is transmitted from a router or an end device, the coordinator stores the address and identification information added to the address in association with each other. If the address is sent from the router or end device, the coordinator checks whether the address is already stored in the memory. If it is stored in the memory, the coordinator stores it in correspondence with the address. And the identification information added to the transmitted address are compared. Here, if both are different, the transmitted address is detected as a duplicate address. In this case, the function to detect duplicate addresses need only be provided in the coordinator, and is not required for other devices (routers and end devices), so it is possible to detect duplication of all addresses in the system with an inexpensive configuration. It becomes.

  According to a second invention (invention according to claim 2), in the first invention, when a duplicate address is detected in the first device, the duplicate address is deleted from the memory, and the duplicate address is deleted in a lower device. A means for sending a request by broadcasting is provided, and when the second device receives a request for deleting a duplicate address from the first device and the address assigned to the second device is a duplicate address, A means for deleting from the memory and a means for making a reconnection request to a higher-level device after acquiring a duplicate address and acquiring an address from the device are provided.

According to the second invention, for example, when the wireless communication system has a two-layer tree structure in which the first device is a coordinator and the second device is a router or an end device, the coordinator detects a duplicate address, The duplicate address is deleted from the memory, and a duplicate address deletion request is sent by broadcast to lower devices (routers and end devices).
When the router or end device receives a duplicate address deletion request from the coordinator and the address assigned to it is a duplicate address, the router or end device deletes the address from its own memory. After deleting the duplicate address, a reconnection request is made to an arbitrary upper device (coordinator), and the address is acquired from the device.
As a result, different addresses are given to devices to which the same address is assigned, and address duplication in the system is automatically resolved.

  A third invention (invention according to claim 3) includes a first device located at the highest level, a second device located at the lowest level and storing an address assigned to the memory in its own memory, In a tree-structured wireless communication system comprising at least a third device that is located between one device and a second device and stores a self-assigned address in its own memory, the second device and the second device 3 is provided with means for periodically transmitting to the first device by adding its own identification information to the address assigned to the third device. The second device and the third device are provided in the first device. Means for associating the transmitted address with the identification information added to the address and storing it in the memory; and the addresses transmitted from the second device and the third device. Is stored in the memory, the identification information stored corresponding to that address is compared with the identification information attached to the transmitted address. Means for detecting the received address as a duplicate address.

  According to the third invention, for example, when a wireless communication system having a three-layer tree structure in which the first device is a coordinator, the second device is an end device, and the third device is a router, the router to the coordinator. In addition, the address assigned to itself is periodically transmitted from the end device to the coordinator via the router with its own identification information added. When an address is transmitted from a router or an end device, the coordinator stores the address and identification information added to the address in association with each other. In addition, when an address is sent from a router or end device, the coordinator checks whether or not the address is already stored in the memory. If it is stored in the memory, the coordinator is stored corresponding to the address. And the identification information added to the transmitted address are compared. Here, if both are different, the transmitted address is detected as a duplicate address. In this case, the function to detect duplicate addresses need only be provided in the coordinator, and is not required for other devices (routers and end devices), so it is possible to detect duplication of all addresses in the system with an inexpensive configuration. It becomes.

  According to a fourth invention (invention according to claim 4), in the third invention, when a duplicate address is detected in the first device, the duplicate address is deleted from the memory, and the duplicate address is deleted in a lower device. A means for sending a request by broadcast is provided, and when the second and third devices receive a duplicate address deletion request from the first device and the address assigned to the second and third devices is a duplicate address, the address Is deleted from its own memory, and after deleting the duplicate address, a reconnection request is made to an arbitrary upper device, and an address is acquired from the device.

According to the fourth aspect of the present invention, for example, when the wireless communication system has a three-layer tree structure in which the first device is a coordinator, the second device is an end device, and the third device is a router, When the address is detected, the duplicate address is deleted from the memory, and a duplicate address deletion request is sent by broadcast to a lower device (router, end device).
In response to a duplicate address deletion request from the coordinator, the router deletes the address from its own memory if the address assigned to it is a duplicate address. After deleting the duplicate address, a reconnection request is made to an arbitrary upper device (coordinator), and the address is acquired from the device.
Similarly to the router, the end device receives a duplicate address deletion request from the coordinator, and when the address assigned to itself is a duplicate address, the end device deletes the address from its own memory. After deleting the duplicate address, a reconnection request is made to an arbitrary upper device (router), and the address is acquired from the device.
As a result, different addresses are given to devices to which the same address is assigned, and address duplication in the system is automatically resolved.

  A fifth invention (invention according to claim 5) is a first device positioned at the highest level, a second device positioned at the lowest level and storing an address assigned to itself in its own memory, In a tree-structured wireless communication system comprising at least a third device that is located between one device and a second device and stores a self-assigned address in its own memory, the second device includes: A means for periodically transmitting the identification information to the higher-order device by adding the identification information to the self-assigned address is provided, and the third device is added with the identification information to the higher-order address. Means for periodically transmitting to a device of the first memory, and an address periodically transmitted from a device one layer below is associated with identification information added to the address in the first memory In the case where the storing means and the address periodically transmitted from the device one layer below are already stored in the first memory, the identification information stored corresponding to the address and the transmitted address Is compared with the identification information added to the device, and if both are different, a means for detecting the transmitted address as a duplicate address is provided. Means for storing the transmitted address in the second memory in association with the identification information added to the address, and the address periodically transmitted from the device one layer below is already stored in the second memory. If it was stored, the identification information stored corresponding to the address was compared with the identification information added to the transmitted address, and both were different. If, it is provided with a means for detecting the address transmitted as a duplicate address.

According to the fifth aspect of the present invention, for example, in the case of a wireless communication system having a three-layer tree structure in which the first device is a coordinator, the second device is an end device, and the third device is a router, The address assigned to itself is periodically transmitted to the other device (router) with its own identification information added. Also, the address assigned to itself is periodically transmitted from the router to the higher-level device (coordinator) with its own identification information added.
When an address is transmitted from a device (end device) one level below, the router associates the address with identification information added to the address and stores it in the first memory. In addition, when an address is transmitted from a device (end device) one layer below, the router checks whether the address is already stored in the first memory, and is stored in the first memory. In the case where the address is stored, the identification information stored corresponding to the address is compared with the identification information added to the transmitted address. Here, if both are different, the transmitted address is detected as a duplicate address.
When an address is transmitted from a device (router) one layer below, the coordinator associates the address with the identification information added to the address and stores it in the second memory. In addition, when an address is transmitted from a device (router) one layer below, the coordinator checks whether or not the address is already stored in the second memory, and is stored in the second memory. In this case, the identification information stored corresponding to the address is compared with the identification information added to the transmitted address. Here, if both are different, the transmitted address is detected as a duplicate address.
In this case, the function for detecting duplicate addresses need only be provided in the coordinator and router, and is not necessary for the end device, so that duplication of all addresses in the system can be detected with an inexpensive configuration.

  According to a sixth invention (invention according to claim 6), in the fifth invention, when a duplicate address is detected in the first device, the duplicate address is deleted from the second memory and duplicated in a lower device. A means for sending an address deletion request by broadcasting is provided. When a duplicate address is detected in the third device, the duplicate address is deleted from the first memory, and a duplicate address deletion request is broadcast to the lower device. If the address assigned to itself is a duplicate address in response to a request for deleting a duplicate address from a higher-level device, the means for deleting the address from its own memory and the duplicate address are deleted. After that, there is a means for requesting reconnection to any upper device and obtaining an address from that device. When the second device receives a duplicate address deletion request from a higher-level device and the assigned address is a duplicate address, means for deleting the address from its own memory, and a duplicate address After deletion, a means for making a reconnection request to an arbitrary upper device and acquiring an address from the device is provided.

According to the sixth aspect of the present invention, for example, when the wireless communication system has a three-layer tree structure in which the first device is a coordinator, the second device is an end device, and the third device is a router, the coordinator When the address is detected, the duplicate address is deleted from the second memory, and a duplicate address deletion request is broadcasted to a lower device (router). When the router detects the duplicate address, the router deletes the duplicate address from the first memory and sends a duplicate address deletion request to the lower device (end device) by broadcast.
When the router receives a duplicate address deletion request from the coordinator, if the address assigned to the router is a duplicate address, the router deletes the address from its own memory. After the duplicate address is deleted, a reconnection request is made to an arbitrary upper device (coordinator), and the address is acquired from the device.
When the end device receives a duplicate address deletion request from the router, if the address assigned to the end device is a duplicate address, the end device deletes the address from its own memory. After the duplicate address is deleted, a reconnection request is made to an arbitrary upper device (router), and the address is acquired from the device.
As a result, different addresses are given to devices to which the same address is assigned, and address duplication in the system is automatically resolved.

  In the present invention, the tree-structured wireless communication system is not limited to a three-layer tree structure, and may be a two-layer tree structure including a first device and a second device. A tree structure having four or more layers in which a plurality of third devices are provided between the first device and the second device may be used. Furthermore, in this tree-structured wireless communication system, there is one first device, but many second devices and third devices are provided depending on the situation. In addition, the present invention can be configured as a single device, not as a wireless communication system. In this case, the device periodically stores the address transmitted from the lower device in association with the identification information added to the address and the address transmitted from the lower device. If it is stored in the memory, the identification information stored corresponding to that address is compared with the identification information added to the transmitted address, and if they are different, the transmitted address Is provided as a duplicate address (seventh invention (invention according to claim 7)). In addition, when a duplicate address is detected, the duplicate address is deleted from the memory, and a means for broadcasting a duplicate address deletion request to a lower device is provided (eighth invention (invention according to claim 8)). In this case, the device may be a coordinator or a router.

According to the first invention, the address assigned to itself from the second device is periodically transmitted to the first device with its own identification information added, and the second device If the transmitted address is already stored in the memory, the identification information stored corresponding to the address is compared with the identification information added to the transmitted address, and the two are different. In this case, since the transmitted address is detected as a duplicate address, a function for detecting the duplicate address is provided only in the first device, so that all addresses in the system are duplicated with an inexpensive configuration. It becomes possible to detect.
According to the second invention, when a duplicate address is detected in the first device, the duplicate address is deleted by broadcasting a duplicate address deletion request to a device lower than the first device. By giving different addresses to assigned devices, it becomes possible to automatically eliminate duplication of all addresses in the system.

According to the third invention, the address assigned to itself from the second device and the third device is periodically transmitted to the first device by adding its own identification information, and in the first device When the addresses transmitted from the second device and the third device are already stored in the memory, the identification information stored corresponding to the addresses and the identification added to the transmitted address Compared with the information, if they are different, the transmitted address is detected as a duplicate address. Therefore, the function for detecting the duplicate address is provided only in the first device. It becomes possible to detect duplication of all addresses with an inexpensive configuration.
According to the fourth invention, when a duplicate address is detected in the first device, the duplicate address is deleted by broadcasting a duplicate address deletion request to a device lower than the first device, and the same address is By giving different addresses to assigned devices, it becomes possible to automatically eliminate duplication of all addresses in the system.

According to the fifth aspect of the invention, the addresses assigned to itself from the second device and the third device are periodically transmitted to the higher-level device with the identification information added thereto, In the device 3, if the address periodically transmitted from the device one layer below is already stored in the memory, it is added to the identification information stored corresponding to the address and the transmitted address. If the two are different from each other, the transmitted address is detected as a duplicate address. Therefore, the function for detecting the duplicate address is provided only in the coordinator and the router. It is possible to detect duplication of all addresses in the memory with an inexpensive configuration.
According to the sixth invention, when a duplicate address is detected in the first device, a duplicate address deletion request is broadcasted to a device lower than the first device, and the duplicate address is also found in the third device. If detected, a duplicate address deletion request is broadcasted to a device lower than the third device, so that the duplicate address is deleted and a different address is given to the device to which the same address is assigned. It becomes possible to automatically eliminate duplication of all addresses.

  According to the seventh aspect of the invention, the device stores the address periodically transmitted from the lower-level device in association with the identification information added to the address, and the transmitted address is already stored. If it is stored in the memory, the identification information stored corresponding to that address is compared with the identification information added to the transmitted address, and if they are different, the transmitted address Is provided as a duplicate address, so that a function for detecting duplicate addresses is provided only in the coordinator, or only in the coordinator and router, so that all addresses in the tree-structured wireless communication system can be detected. Duplication can be detected with an inexpensive configuration.

  According to the eighth invention, when a duplicate address is detected in the device of the seventh invention, means for deleting the duplicate address from the memory and sending a duplicate address deletion request to the lower device by broadcasting are provided. Therefore, a duplicate address deletion request is given to a device lower than the coordinator, or a duplicate address deletion request is given to a device lower than the router, and the duplicate address is deleted. By giving different addresses, it becomes possible to automatically eliminate duplication of all addresses in the tree-structured wireless communication system.

Hereinafter, the present invention will be described in detail with reference to the drawings.
[Embodiment 1: System in which duplicate detection function is provided only in coordinator]
FIG. 1 is a schematic diagram showing an example (Embodiment 1) of a wireless communication system according to the present invention. This wireless communication system is a simple example using a ZigBee network. The coordinator 10 is located at the highest level (0th layer), the end device 30 is located at the lowest level (second layer), the coordinator 10 and the end. The router 20 is located between the devices 30 (first layer).

  In this example, the identification number of the coordinator 10 is # 0, the identification numbers of the routers 20-1 and 20-2 are # 1 and # 2, and the identification numbers of the end devices 30-1 to 30-4 are # 3 to #. It is assumed that 6 is set. In this wireless communication system, the coordinator 10 is defined with address blocks AD0 to AD6 as addresses that can be assigned to the entire network, and among these address blocks, “AD0” is assigned as its own address. To do.

  Also in this wireless communication system, similarly to the ZigBee network shown in FIG. 13, when the router 20-1 is connected to the coordinator 10, the router 20-1 is brought close to the coordinator 10 and the power is turned on. Then, an associate connection request is sent from the router 20-1 to the coordinator 10, and a parent-child relationship is established with the coordinator 10. As a result, the address AD1 is assigned to the router 20-1, and the correspondence between the address AD1 assigned to the router 20-1 and the identification number # 1 is written in the connection information table T0 of the coordinator 10.

  Similarly, between the coordinator 10 and the router 20-2, between the router 20-1 and the end devices 30-1 and 30-2, and between the router 20-2 and the end devices 30-3 and 30-4. The parent-child relationship is concluded. As a result, the address AD4 is assigned to the router 20-2, and the correspondence between the address AD4 assigned to the router 20-2 and the identification number # 2 is written in the connection information table T0 of the coordinator 10. The addresses AD2 and AD3 are assigned to the end devices 30-1 and 30-2, and the addresses AD2 and AD3 and the identification numbers assigned to the end devices 30-1 and 30-2 in the connection information table T1 of the router 20-1. The correspondence with # 3 and # 4 is written. The addresses AD5 and AD6 are assigned to the end devices 30-3 and 30-4, and the addresses AD5 and AD6 and the identification numbers assigned to the end devices 30-3 and 30-4 in the connection information table T1 of the router 20-2. The correspondence with # 5 and # 6 is written.

  In this wireless communication system, the router 20 and the end device 30 have a function of adding their own identification information to addresses assigned to themselves and periodically transmitting them to the coordinator 10. For example, the end device 30-1 adds its own identification number # 3 to the address AD2 assigned to itself and sends it to the coordinator 10 via the router 20-1. The router 20-1 adds its own identification number # 1 to the address AD1 assigned to itself and sends it to the coordinator 10.

  In this wireless communication system, the coordinator 10 also writes the address periodically sent from the router 20 and the end device 30 in association with the identification number added to the address in the duplicate detection address table TA. (Duplicate detection address storage function) When the address periodically sent from the router 20 and the end device 30 has already been written in the table TA, the identification information and the notification address written in correspondence with the address Compared with the identification information added to the URL, if both are different, the function to detect the sent address as a duplicate address (duplicate address detection function), if a duplicate address is detected, the duplicate address is It is deleted from the duplicate detection address table TA and its address Is a connection information table T0 that defines a function (duplicate address deletion request function) that gives a lower address device (router 20, end device 30) a request for deleting a duplicate address by broadcast and a parent-child relationship with the lower device. Has a function of deleting connection information including the address (connection information deletion function).

  Also, in this wireless communication system, when the router 20 and the end device 30 receive a duplicate address deletion request from the coordinator 10 and the address (self address) assigned to it is a duplicate address, the address Has a function to delete the IP address (duplicate address deletion function) and a function to request reconnection to any upper device after deleting the duplicate address and acquire the address from that device (address reacquisition function) . In addition to the duplicate address deletion function and the address reacquisition function described above, the router 20 receives a duplicate address deletion request from the coordinator 10 and duplicates the connection information table T1 that defines the parent-child relationship with the lower device. When an address is included, the connection information including the address is deleted (connection information deletion function).

  FIG. 2 shows a schematic block diagram of the coordinator 10. The coordinator 10 includes a processing unit 10A, a RAM 10B, an EEPROM 10C, and an RF circuit (wireless transmission / reception circuit) 10D. In addition to the above-described duplicate detection address storage function, duplicate address detection function, duplicate address deletion request function, and connection information deletion function, the processing unit 10A includes a network declaration function, a parent node function, a communication function (node Inter-communication function, communication relay function). These functions are obtained as processing operations according to a program executed by the processing unit 10A. The EEPROM 10C stores an identification number of the coordinator 10, an address block that can be assigned to the entire network, an address assigned to the coordinator 10, a connection information table T0, a duplicate detection address table TA, and the like.

  FIG. 3 shows a schematic block diagram of the router 20. The router 20 includes a processing unit 20A, a RAM 20B, an EEPROM 20C, and an RF circuit 20D. The processing unit 20A includes a parent node function, a communication function (inter-node communication function, communication relay function) and the like as basic functions in addition to the above-described duplicate address deletion function, address reacquisition function, and connection information deletion function. Yes. These functions are obtained as processing operations according to a program executed by the processing unit 20A. The EEPROM 20C stores an identification number of the router 20, an address block that can be assigned to a lower device sent from a higher device, a connection information table T1, and the like. The RAM 20B stores an address assigned to the router 20 and the like.

  FIG. 4 shows a schematic block diagram of the end device 30. The end device 30 includes a processing unit 30A, a RAM 30B, an EEPROM 30C, and an RF circuit 30D. The processing unit 30A includes a child node function, a communication function (inter-node communication function), and the like as basic functions in addition to the duplicate address deletion function and the address reacquisition function described above. These functions are obtained as processing operations according to a program executed by the processing unit 30A. The EEPROM 30C stores an identification number of the end device 30 and the like. The RAM 30B stores an address assigned to the end device 30 and the like.

[Duplicate address]
In this wireless communication system, after the router 20 assigns an address to a lower device, the connection information table T1 in the router 20 may be lost due to some accident. Here, when a new device requests a parent-child connection to the router 20 in which the connection information table T1 has been lost, there is a possibility that an already assigned address is duplicated and assigned to the device that has obtained the parent-child connection. .

  For example, as shown in FIG. 5A, the connection information table T1 of the router 20-1 has a parent-child relationship with the end device 30-1, but the parent-child relationship with the end device 30-2. The relationship has not yet been established. Here, it is assumed that the connection information table T1 in the router 20-1 is lost due to some abnormality (FIG. 5B), and the parent-child relationship between the router 20-1 and the end device 30-1 is lost. In this state, for example, when the end device 30-2 is brought close to the router 20-1 and the power is turned on (FIG. 5C), an associate connection request is sent from the end device 30-2 to the router 20-1. A parent-child relationship is established with the router 20-1.

  In this case, the router 20-1 determines that the addresses AD2 and AD3 remain as addresses that can be assigned to the lower device, assigns the address AD2 to the end device 30-2, and also assigns the end device 30- 2 is associated with the address AD2 assigned to the end device 30-2 and written in the connection information table T1 as having a parent-child relationship. For this reason, the address of the end device 30-1 and the address of the end device 30-2 become the same address AD2, and address duplication occurs.

[Duplicate address detection]
When the address AD2 is assigned from the router 20-1, the end device 30-2 periodically adds its own identification number # 4 to the address AD2 assigned to itself, and passes through the router 20-1. The data is sent to the coordinator 10 (FIG. 5D).

  The coordinator 10 receives the address (notification address + identification number) sent from the end device 30-2 (YES in step 101 shown in FIG. 6), and the notification address from the end device 30-2 is a duplicate detection address. It is checked whether data is written in the table TA (step 102). Here, if the notified address is not written in the duplicate detection address table TA, the notified address is written in the duplicate detection address table TA in correspondence with the identification number added to the address. (Step 103).

  When the notified address is written in the duplicate detection address table TA, the identification number corresponding to the address is read from the duplicate detection address table TA, and the identification number added to the notified address and Compare. If the identification numbers are different, the notified address is determined as a duplicate address (step 104), and the address is deleted from the duplicate detection address table TA together with the corresponding identification number (step 105).

  Then, it is checked whether or not the address determined to be a duplicate address is included in the connection information table T0 (step 106). If it is included in the connection information table T0, the connection information including the duplicate address is connected. After deleting from the information table T0 (step 107), a duplicate address deletion request is sent by broadcast to the lower device (step 108).

  If the addresses are the same and the identification numbers are the same, the process returns to step 101 without doing anything. If the identification numbers are the same and the addresses are different, the addresses are deleted from the duplicate detection address table TA (step 109), and the notified address is used as a new address corresponding to the identification number. Write to table TA (step 103).

  In the example shown in FIG. 5D, the coordinator 10 receives the address AD2 from the end device 30-2 (YES in Step 101). In this case, since the notified address AD2 is written in the duplication detection address table TA, the identification number # 3 corresponding to the address is read from the duplication detection address table TA and added to the notification address AD2. Compare with identification number # 4.

  As a result of this comparison, since the identification numbers are different, the coordinator 10 determines that the notified address AD2 is a duplicate address (step 104) and deletes the address AD2 from the duplicate detection address table TA together with the corresponding identification number ( Step 105: FIG. 7 (a)).

  Then, after confirming that the notified address AD2 is not included in the connection information table T0 (NO in step 106), the address AD2 is used as a request address, and a duplicate address deletion request is broadcasted to a lower-level device ( Step 108, FIG. 7 (a)).

  In this example, the identification number # 3 associated with the address AD2 determined to be a duplicate address is also deleted from the duplicate detection address table TA, but the identification number is left without being deleted. It may be.

[Resolve address duplication]
In response to the duplicate address deletion request from the coordinator 10 (FIG. 8: YES in step 201), the router 20 checks whether the requested address is its own address (step 202). If the request address is the self address (YES in step 202), the self address is deleted (step 203). If the request address is not its own address (NO in step 202), it is checked whether or not the request address is included in the connection information table T1 (step 206).

  In this case, since the request address is the address AD2, not the own address, the process proceeds to step 206 in response to NO in step 202, and it is checked whether or not the request address AD2 is included in the connection information table T1. Then, it is confirmed that the request address AD2 is included in the connection information table T1 (YES in Step 206), and the connection information including the request address AD2 is deleted from the connection information table T1 (Step 207, FIG. 7). (B)).

  When the request address is the own address (YES in Step 202), the router 20-1 deletes the own address by turning off its own power (Step 203). Then, it is restarted, an associate connection request (reconnection request) is sent to an arbitrary upper device (in this example, the coordinator 10), and an address is acquired from the device (steps 204 and 205).

  Upon receiving the duplicate address deletion request from the coordinator 10 (FIG. 9: YES in step 301), the end device 30-1 checks whether the requested address is its own address (step 302). If the request address is the self address (YES in step 302), the self address is deleted (step 303).

  In this case, since the request address is the address AD2 and is the own address, the process proceeds to step 303 in response to YES in step 302, and the own address is erased by turning off its own power supply (FIG. 7B). After a predetermined time elapses after the power is turned off, the power of the device is turned on (restarted), and an associate connection request (reconnection request) is sent to an arbitrary upper device (in this example, the router 20-1). The address is acquired from the device (steps 304 and 305).

  In this case, as shown in FIG. 7C, an associate connection request is sent from the end device 30-1 to the router 20-1 (arrow (1)), and the address AD2 is stored in the connection information table T1 of the router 20-1. The correspondence with the identification number # 3 is written as having a parent-child relationship (arrow (2)), and the address AD2 is assigned to the end device 30-1 (arrow (3)).

  Upon receiving the duplicate address deletion request from the coordinator 10 (FIG. 9: YES in step 301), the end device 30-2 checks whether the request address is its own address (step 302). If the request address is the self address (YES in step 302), the self address is deleted (step 303).

  In this case, since the request address is the address AD2 and is the own address, the process proceeds to step 303 in response to YES in step 302, and the own address is erased by turning off its own power supply (FIG. 7B). After a predetermined time elapses after the power is turned off, the power of the device is turned on (restarted), and an associate connection request (reconnection request) is sent to an arbitrary upper device (in this example, the router 20-1). The address is acquired from the device (steps 304 and 305).

  In this case, as shown in FIG. 7C, an associate connection request is sent from the end device 30-3 to the router 20-1 (arrow (4)), and the address AD3 is stored in the connection information table T1 of the router 20-1. The correspondence with the identification number # 4 is written as having a parent-child relationship (arrow (5)), and the address AD3 is assigned to the end device 30-2 (arrow (6)).

  In the above description, the case where address duplication occurs between the end devices 30-1 and 30-2 has been described, but the case where address duplication occurs between the routers 20-1 and 20-2 is also described. In the same manner as between the end devices 30-1 and 30-2, duplication of addresses is detected by the coordinator 10 and automatically resolved.

  Although a simple example is shown in FIG. 1, there are actually several layers of routers 20 between the highest level coordinator 10 and the lowest level end device 30. The number of devices 30 is also increased, resulting in a large-scale wireless communication system. In such a system as well, as in the case shown in FIG. 1, the coordinator 10 can detect duplication of all addresses in the system and automatically eliminate them.

  As described above, in the system according to the first embodiment, only the coordinator 10 needs to have an address duplication detection function, and the router 20 and the end device 30 do not have to have an address duplication detection function. With the configuration, it is possible to detect the duplication of all addresses in the system.

[Embodiment 2: System in which coordinator's duplicate address detection function is distributed to routers]
In the first embodiment, since only the coordinator 10 detects all duplications in the system, the processing load on the coordinator 10 and the communication load on the entire system increase. Therefore, in the second embodiment, a system in which the duplicate address detection function of the coordinator 10 is distributed to the router 20 is assumed to reduce the processing load of the coordinator 10 and the communication load of the entire system.

  In the second embodiment, as shown in FIG. 10, the end device 30-1, 30-2 periodically sends its own address to the router 20-1 with its own identification number added, The end device 30-3, 30-4 periodically sends its own address to the router 20-2 with its own identification number added to the routers 20-1 and 20-2 with respect to the device one layer below. A duplicate detection address table TB is created. Further, the router 20-1, 20-2 periodically sends its own address to the coordinator 10 with its own identification number added, and the coordinator 10 is provided with a duplicate detection address table TA for the device one layer below. Let it be created.

[Duplicate address]
For example, as shown in FIG. 11A, the connection information table T1 of the router 20-1 has a parent-child relationship with the end device 30-1, but the parent-child relationship with the end device 30-2. The relationship has not yet been established. In addition, it is assumed that the address of the end device 30-1 is written in correspondence with the identification number in the duplication detection address table TB of the router 20-1.

  Here, it is assumed that the connection information table T1 in the router 20-1 is lost due to some abnormality (FIG. 11B), and the parent-child relationship between the router 20-1 and the end device 30-1 is lost. In this state, for example, when the end device 30-2 is brought close to the router 20-1 and the power is turned on (FIG. 11C), an associate connection request is sent from the end device 30-2 to the router 20-1. A parent-child relationship is established with the router 20-1.

  In this case, the router 20-1 assigns the address AD2 to the end device 30-2, and associates the identification number # 4 of the end device 30-2 with the address AD2 assigned to the end device 30-2. Write to the connection information table T1 as having a relationship. For this reason, the address of the end device 30-1 and the address of the end device 30-2 become the same address AD2, and address duplication occurs.

[Duplicate duplicate address detection]
When the address AD2 is assigned from the router 20-1, the end device 30-2 periodically adds its own identification number # 4 to the address AD2 assigned to itself and sends it to the router 20-1 (FIG. 11). (D)).

  The router 20-1 receives the address (notification address + identification number) sent from the end device 30-2, and whether the notification address from the end device 30-2 is written in the duplication detection address table TB. To check. In this case, since the notified address AD2 is written in the duplicate detection address table TB, the identification number # 3 corresponding to the address is read from the duplicate detection address table TB and added to the notified address AD2. The identification number # 4 is compared.

  Since the identification numbers are different as a result of the comparison, the router 20-1 determines that the notified address AD2 is a duplicate address, and deletes the address AD2 from the duplicate detection address table TB together with the corresponding identification number (FIG. 12). (A)). Further, it is confirmed that the notified address AD2 is included in the connection information table T1, the address AD2 is deleted from the connection information table T1, the address AD2 is used as a request address, and the end devices 30-1 and 30- 2 sends a duplicate address deletion request by broadcast (FIG. 12A).

[Resolve address duplication]
Upon receiving the duplicate address deletion request from the router 20-1, the end device 30-1 checks whether the requested address is its own address. In this case, the request address is the address AD2, and is the self address, so the power supply of the self is turned off and the self address is deleted (FIG. 12B).

  Then, after a predetermined time has elapsed after the power supply is turned off, the power supply is turned on (restarted), an associate connection request (reconnection request) is sent to the router 20-1, and the address AD2 is obtained from the router 20-2. (FIG. 12C). As a result, the address AD2 is written in the connection information table T1 of the router 20-1 as having a parent-child relationship in association with the identification number # 3 of the end device 30-1.

  Upon receiving the duplicate address deletion request from the router 20-1, the end device 30-2 checks whether or not the request address is its own address. In this case, the request address is the address AD2, and is the self address, so the power supply of the self is turned off and the self address is erased (FIG. 12B).

  Then, after a predetermined time has elapsed after the power supply is turned off, the power supply is turned on (restarted), an associate connection request (reconnection request) is sent to the router 20-1, and the address AD3 is obtained from the router 20-2. (FIG. 12C). As a result, the address AD3 is written in the connection information table T1 of the router 20-1 in association with the identification number # 4 of the end device 30-2 as having a parent-child relationship.

  When the address AD2 is assigned from the router 20-1, the end device 30-1 periodically adds its own identification number # 3 to the address AD2 assigned to itself and sends it to the router 20-1. Similarly, when the address AD3 is assigned from the router 20-1, the end device 30-2 periodically adds its own identification number # 4 to the address AD3 assigned to itself and sends it to the router 20-1. As a result, the duplicate address detection table TB in which the notification addresses from the end devices 30-1 and 30-2 are written in correspondence with the identification numbers is created in the router 20-1 (FIG. 12D).

  In the above description, the case where address duplication occurs between the end devices 30-1 and 30-2 has been described. However, when address duplication occurs between the routers 20-1 and 20-2, the end In the same manner as between the devices 30-1 and 30-2, duplication of addresses is detected by the coordinator 10 and automatically resolved.

  Although a simple example is shown in FIG. 10, there are actually several layers of routers 20 between the highest level coordinator 10 and the lowest level end device 30. The number of devices 30 is also increased, resulting in a large-scale wireless communication system. Even in such a system, as in the case shown in FIG. 10, duplication of all addresses in the system can be detected and automatically resolved by the coordinator 10 and the router 20.

  Thus, in the system of the second embodiment, only the coordinator 10 and the router 20 need be provided with an address duplication detection function, and the end device 30 does not have to be provided with an address duplication detection function. With the configuration, it is possible to detect the duplication of all addresses in the system.

It is the schematic which shows an example (Embodiment 1) of the radio | wireless communications system which concerns on this invention. It is a schematic block diagram of the coordinator used for this radio | wireless communications system. It is a schematic block diagram of the router used for this radio | wireless communications system. It is a schematic block diagram of the end device used for this radio | wireless communications system. It is a figure explaining the process of the detection of the duplicate address in this radio | wireless communications system. It is a flowchart which shows the processing operation at the time of the detection of the duplicate address in a coordinator. It is a figure explaining the process of address duplication elimination in this radio | wireless communications system. It is a flowchart which shows the processing operation at the time of address duplication elimination in a router. It is a flowchart which shows the processing operation at the time of address duplication resolution in an end device. It is the schematic which shows the other example (Embodiment 2) of the radio | wireless communications system which concerns on this invention. It is a figure explaining the process of the detection of the duplicate address in this radio | wireless communications system. It is a figure explaining the process of address duplication elimination in this radio | wireless communications system. It is a figure which shows the simple example of the conventional ZigBee network. It is a figure explaining the duplication of the address which may arise in this ZigBee network.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Coordinator, 10A ... Processing part, 10B ... ROM, 10C ... EEPROM, 10D ... RF circuit, 20 (20-1, 20-2) ... Router, 20A ... Processing part, 20B ... ROM, 20C ... EEPROM, 20D ... RF circuit, 30 (30-1 to 30-4) ... end device, 30A ... processing unit, 30B ... ROM, 30C ... EEPROM, 30D ... RF circuit, T0, T1 ... connection information table, TA, TB ... duplicate address detection For table.

Claims (8)

In a tree-structured wireless communication system comprising at least a first device located at the highest level and a second device located at the lowest level and storing a self-assigned address in its own memory,
The second device is:
Means for periodically transmitting to the first device by adding its own identification information to an address assigned to itself;
The first device is:
Means for storing the address transmitted from the second device in the memory in association with the identification information added to the address;
When the address transmitted from the second device is already stored in the memory, the identification information stored corresponding to the address is compared with the identification information added to the transmitted address. And a means for detecting the transmitted address as a duplicate address when they are different from each other. The wireless communication system according to claim 1, wherein
The first device further includes:
When the duplicate address is detected, the duplicate address is deleted from the memory, and a means for sending a duplicate address deletion request to a lower device by broadcasting is provided.
The second device further includes:
In response to the duplicate address deletion request from the first device, if the address assigned to itself is a duplicate address, means for deleting the address from its own memory;
A wireless communication system comprising: means for making a reconnection request to an arbitrary upper device after acquiring the duplicate address, and acquiring an address from the device. A first device located at the top, a second device located at the bottom and storing the address assigned to it in its own memory, and located between the first device and the second device A tree-structured wireless communication system comprising at least a third device for storing an address assigned to the memory in its own memory;
The second device and the third device are:
Means for periodically transmitting to the first device by adding its own identification information to an address assigned to itself;
The first device is:
Means for storing the addresses transmitted from the second device and the third device in a memory in association with the identification information added to the addresses;
When the addresses transmitted from the second device and the third device are already stored in the memory, the identification information stored corresponding to the addresses and the transmitted address are added. A wireless communication system comprising: means for comparing the identification information and, if they are different from each other, detecting the transmitted address as a duplicate address. The wireless communication system according to claim 3,
The first device further includes:
When the duplicate address is detected, the duplicate address is deleted from the memory, and a means for sending a duplicate address deletion request to a lower device by broadcasting is provided.
The second and third devices further include:
In response to the duplicate address deletion request from the first device, if the address assigned to itself is a duplicate address, means for deleting the address from its own memory;
A wireless communication system comprising: means for making a reconnection request to an arbitrary upper device after acquiring the duplicate address, and acquiring an address from the device. A first device located at the top, a second device located at the bottom and storing the address assigned to it in its own memory, and located between the first device and the second device A tree-structured wireless communication system comprising at least a third device for storing an address assigned to the memory in its own memory;
The second device is:
A means for periodically transmitting to an upper device by adding its own identification information to an address assigned to itself,
The third device is:
Means for periodically transmitting to the higher-level device by adding its own identification information to the address assigned to itself;
Means for associating an address periodically transmitted from a device under one layer with the identification information added to the address in a first memory;
When the address periodically transmitted from the device one layer below is already stored in the first memory, the identification information stored corresponding to the address is added to the transmitted address. And a means for detecting the transmitted address as a duplicate address when both are different from each other,
The first device is:
Means for associating an address periodically transmitted from a device under one layer with the identification information added to the address in a second memory;
When the address periodically transmitted from the device one layer below is already stored in the second memory, the identification information stored corresponding to the address is added to the transmitted address. And a means for detecting the transmitted address as a duplicate address when they are different from each other. The wireless communication system according to claim 5, wherein
The first device further includes:
When the duplicate address is detected, the duplicate address is deleted from the second memory, and a duplicate address deletion request is broadcasted to a lower-level device.
The third device further includes:
When the duplicate address is detected, the duplicate address is deleted from the first memory, and a duplicate address deletion request is broadcasted to a lower device, and
In response to a duplicate address deletion request from a higher-level device, if the address assigned to itself is a duplicate address, means for deleting the address from its own memory;
A means for performing a reconnection request to an arbitrary upper device after deleting the duplicate address, and obtaining an address from the device; and
The second device further includes:
In response to a duplicate address deletion request from a higher-level device, if the address assigned to itself is a duplicate address, means for deleting the address from its own memory;
A wireless communication system comprising: means for making a reconnection request to an arbitrary upper device after acquiring the duplicate address, and acquiring an address from the device. Means for storing the address periodically transmitted from the lower-level device in the memory in association with the identification information added to the address;
When an address periodically transmitted from the lower device has already been stored in the memory, identification information stored corresponding to the address and identification information added to the transmitted address; And a means for detecting the transmitted address as a duplicate address when the two are different from each other. The device of claim 7, further comprising:
A device comprising: means for deleting a duplicate address from the memory when the duplicate address is detected, and sending a duplicate address deletion request to a lower device by broadcast.

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