JP2008054127A - Gateway device, data aggregating device, data aggregation system, data transmission method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently transmit data to a data aggregating device, by flexibly coping with data amount fluctuation that is difficult to predict, while preventing the data aggregating device from overloading, in a data aggregation system provided with a plurality of gateway devices and the data aggregating device having the plurality of gateway devices serve under. <P>SOLUTION: A gateway device transmits data from a queue buffer, on the basis of a transmission resource allocation table including time slot information showing timing for transmitting data to the data aggregating device and transmission data amount information at transmitting timing, determines the transmission resource requiring quantity, needed on the basis of a queue buffer state, transmits the transmission resource requiring quantity needed to the data aggregating device, and uses a transmission resource assignment table received from the data aggregating device, according to the transmission from the transmission resource, requiring the quantity needed as a new transmission resource assignment table. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sensor data aggregation system that aggregates sensor data transferred from a large number of sensors via a network.

  2. Description of the Related Art A sensor management system in which sensors such as door opening / closing detection sensors are installed at a base such as a building and an abnormality is monitored on the center side is widespread. Generally, a plurality of various sensors are installed in a base, and a gateway device that receives data sent from the sensors (referred to as sensor data) via a sensor reader and transmits it to the center side is installed. Is done. The center side is provided with a data aggregating device that aggregates sensor data from a plurality of gateway devices installed at each base via a network and performs processing (such as abnormality notification) based on the sensor data.

  In such a sensor management system, when the bases where the sensors are installed spread and the number of sensors becomes very large, a large amount of sensor data is sent to the data aggregating device, which causes an overload of the data aggregating device and network congestion Problems can arise.

  A technique for efficiently aggregating data transmitted from a large number of viewer terminals to the center of a broadcasting station in relation to aggregating data is described in Patent Document 1. In the technique of Patent Document 1, the center side estimates the next aggregation target terminal number from the trend of increase / decrease in the number of aggregation target terminals, determines the call probability value, and transmits it to each terminal. Whether to make a call is determined by comparing the call probability value with a random number.

  However, in the technique of Patent Document 1, since estimation of the number of terminals to be aggregated and determination of call probability values are all performed on the center side, this technique is applied to a sensor management system that is expected to use a huge number of sensors. Is applied, the load on the data aggregation device becomes excessive.

In addition to the periodic detection sensor that periodically sends sensor data, such as a temperature detection sensor, there is an event-driven detection sensor that sends sensor data when something happens. However, in event-driven detection sensors, there are fluctuations in the data amount that cannot be predicted due to a tendency to increase or decrease. Appropriate transmission control cannot be performed for such data for which it is difficult to predict the transmission timing, even if the technique of Patent Document 1 that performs estimation based on the increasing / decreasing tendency of the number of aggregation target terminals is applied.
JP 2003-283690 A

  The present invention has been made in view of the above points. In a data aggregation system including a plurality of gateway devices and a data aggregation device having the plurality of gateway devices under control, the data aggregation device is overloaded. It is an object of the present invention to provide a technique for flexibly dealing with fluctuations in the amount of data that is difficult to predict and efficiently transmitting data to a data aggregation device.

  The above-described problem is provided with a plurality of gateway devices that receive data transmitted from a plurality of data transmission devices, and further includes a data aggregation device that aggregates data of the data transmission devices transmitted from the plurality of gateway devices. The gateway device in the aggregation system, a queue buffer for temporarily storing data received from the data transmission device as a queue, and a time indicating a timing for transmitting the data stored in the queue buffer to the data aggregation device A transmission resource allocation table storing means for storing a transmission resource allocation table including slot information and transmission data amount information at transmission timing, and referring to the transmission resource allocation table stored in the transmission resource allocation table storage means, Ties shown in the transmission resource allocation table Based on slot information and transmission data amount information, data transmission means for transmitting data from the queue buffer to the data aggregating device, and monitoring the state of the queue buffer, and determining the transmission resource required amount based on the state, The transmission resource allocation table is transmitted to the data aggregation device, and the transmission resource allocation table received from the data aggregation device in response to the transmission resource requirement transmission is replaced with the existing transmission resource allocation table. This is solved by a gateway apparatus comprising transmission resource allocation table updating means for storing in resource allocation table storage means.

  In the gateway device, the transmission resource allocation table update means may update the transmission resource allocation table by periodically transmitting the transmission resource required amount to the data aggregation device.

  In addition, the transmission resource allocation table updating means may determine the number of times that data does not exist in the queue buffer at a transmission timing indicated by the time slot information within a predetermined period, and a predetermined time or more in the queue buffer. The transmission resource requirement amount may be determined from the data amount accumulated during the period.

  Further, the transmission resource allocation table updating means updates the transmission resource allocation table by transmitting the transmission resource required amount to the data aggregation device when the queue buffer is in a predetermined state. It may be. In this case, the predetermined state may be that the free capacity of the queue buffer is equal to or less than a predetermined amount.

  When the plurality of data transmission devices include a periodic data transmission device that periodically transmits data and an event-driven data transmission device that transmits data in response to occurrence of a specific event, the gateway The apparatus includes, as the queue buffer, a periodic data queue buffer for accumulating periodic data that is data transmitted from the periodic data transmitter, and an event-driven type that is data transmitted from the event-driven data transmitter An event-driven data queue buffer for storing data, and the transmission resource allocation table storage means stores a transmission resource allocation table for each of the periodic data queue buffer and the event-driven data queue buffer, Data transmission means refer to the transmission resource allocation table for each queue buffer. It performs data transmission, the transmission resource allocation table update unit updates the transmission resource allocation table for each of the queue buffer.

  Further, the present invention includes a plurality of gateway devices that receive data transmitted from a plurality of data transmission devices, and further includes a data aggregation device that aggregates data of the data transmission devices transmitted from the plurality of gateway devices. The data aggregation device in a data aggregation system, wherein a time indicating a timing at which the gateway device receives a transmission resource requirement from the gateway device and transmits the data to the data aggregation device based on the transmission resource requirement Transmission resource allocation table generating means for generating a transmission resource allocation table including slot information and transmission data amount information at transmission timing, and transmitting the transmission resource allocation table to the gateway device that has transmitted the required transmission resource amount Characterized by comprising means It may be configured as an aggregate device.

  The transmission resource allocation table can be managed to include time slot information and transmission data amount information allocated for the gateway device to transmit the transmission resource required amount. Note that the time slot information assigned by the gateway device to transmit the transmission resource requirement amount includes information on a first time slot used by the gateway device to periodically transmit the transmission resource requirement amount, and Including information on a second time slot used to transmit a required amount of transmission resources when the gateway device detects a predetermined state, and the time interval of the second time slot is the first time slot It may be smaller than the time interval.

  The data aggregating apparatus has an entire transmission resource allocation table including transmission data amount information allocated for each time slot for all subordinate gateway apparatuses, and the transmission resource allocation table creating means includes the entire transmission It may be determined whether or not transmission resources can be assigned to a specific gateway device with reference to a resource assignment table.

  According to the present invention, since the gateway device autonomously calculates a necessary resource amount, the data aggregation device can be prevented from being overloaded. Further, the gateway device can appropriately transmit a necessary resource amount to the data aggregation device, and the data aggregation device performs resource allocation accordingly, so that it is possible to flexibly cope with a data amount fluctuation that is difficult to predict.

  Embodiments of the present invention will be described below with reference to the drawings. First, the basic configuration and processing contents will be described, and then the apparatus configuration and processing contents will be described in detail.

(Basic configuration and processing contents)
A system configuration in this embodiment is shown in FIG. As shown in FIG. 1, this system includes a data aggregation device 1 and a plurality of gateway devices 3, which are connected by a network 2. A plurality of sensors exist under each gateway device 3, sensor data is transmitted from each sensor to the sensor reader wirelessly, and sensor data is transmitted from the sensor reader to the gateway device 3. A wireless sensor network is configured by the gateway device 3 and the sensors under the gateway device 3. The network 2 is, for example, a satellite communication network, an IP network, a wireless access network, or the like.

  In the present embodiment, the data aggregating apparatus 1 creates a schedule table by receiving from the gateway apparatus 3 the amount of resources that the gateway apparatus 3 needs to transmit sensor data and allocating the resources to time slots. , It is transmitted to the gateway device 3.

  The gateway device 3 includes a queue buffer (hereinafter simply referred to as a queue) that temporarily accumulates sensor data transmitted from the sensor, and the assigned time slot described in the schedule table received from the data aggregation device 1 At the timing, the sensor data accumulated in the queue is transmitted to the data aggregation device 1. Information on the amount of data transmitted at this timing is also described in the schedule table. In addition, the necessary resource amount determined by the queue usage status is appropriately transmitted to the data aggregation device 1.

  The above resources are called time resources, and the minimum time resource allocated to the gateway device 3 is called a unit time resource. Further, the schedule table is created with a predetermined period as one unit, and this period is called a schedule unit period.

  The time per unit time resource (= time slot time), the maximum transmission bandwidth, and the length of the schedule unit period (number of time slots) are common to all gateway devices under the data aggregation device 1. Also, it is assumed that the data aggregation device 1 and all gateway devices 3 are synchronized in time.

  With reference to FIG. 2, an example in which sensor data is transmitted according to the allocated time resource will be described. FIG. 2 shows an example in which the time length of the unit time resource, that is, the time length of one time slot is 2.5 seconds, the maximum transmission bandwidth is 50 bytes, and the schedule unit period is 1 minute. Since the time length of the unit time resource is 2.5 seconds, there are 24 time slots in the schedule unit period (1 minute).

  In the example of FIG. 2, one unit time resource is allocated to each of the 3 and 19 time slots, and two unit time resources are allocated to the 11 time slots. That is, sensor data of a maximum of 50 bytes can be transmitted in each of the 3 and 19 time slots, and sensor data of a maximum of 100 bytes can be transmitted in the 11 time slots.

  The gateway device 3 refers to the schedule table, and transmits the sensor data stored in the queue to the data aggregation device 1 when the time slot is assigned the time resource. For example, when the time of 11 time slots is reached, sensor data from the sensor data accumulated in the queue up to the maximum number of transmittable bytes (100 bytes) is acquired, and the sensor data is transferred to the data aggregating apparatus 1. Since the schedule unit period is 1 minute, the sensor data accumulated in the queue is transferred every minute according to the assignment shown in FIG.

  Further, the gateway device 3 sends the number of time resource requests, which is a necessary amount of time resources, to the data aggregating device 1 at predetermined time intervals or when the queue is in a predetermined state (low free space in the queue). The data aggregation device 1 assigns time resources, creates a new schedule table, and the gateway device 3 receives the schedule table, and stores the received schedule table in place of the existing schedule table. The schedule table is updated by storing the data in and the sensor data is transferred according to the schedule table.

  In the present embodiment, the number of time resource requests sent at predetermined intervals is called a normal time resource request number, and the allocation of time resources based on this is called normal time resource allocation. Further, the number of time resource requests transmitted when the queue free capacity is reduced is called the emergency time resource request number, and the time resource allocation based on this is called emergency time resource allocation. Details on how to determine the amount of time resources required and the creation of the schedule table will be described in detail later.

As described above, the sensor includes a periodic detection sensor that transmits sensor data in a predetermined cycle and an event-driven detection sensor that transmits sensor data only when a specific event occurs. is there. Since the time characteristics of data transmission in both sensors are different, the gateway device 3 of the present embodiment has a queue (periodic detection) that accumulates sensor data (referred to as periodic detection sensor data) received from a sensor of periodic detection. A sensor data queue) and a queue for storing sensor data (referred to as event-driven detection sensor data) received from an event-driven detection sensor (referred to as an event-driven detection sensor data queue). In addition, time resource allocation and data transmission control based on a schedule table are individually performed for each queue.
An outline of the operation of the system when sensor data is transferred using two queues will be described with reference to FIG.

  In the present embodiment, the gateway device 3 has a correspondence table as shown in FIG. 4 in which the ID of each sensor is associated with the type of data to be transmitted. The gateway device 3 refers to the correspondence table based on the sensor ID included in the sensor data, thereby identifying the type of sensor data received from the sensor, and accumulates the sensor data in a queue corresponding to the sensor data.

  Then, the gateway device 3 transfers the sensor data from the periodic detection sensor data queue to the data aggregation device 1 according to the time resource allocation for the periodic detection sensor data, and according to the time resource allocation for the event-driven detection sensor data. Then, the sensor data is transferred from the event-driven detection sensor data queue to the data aggregation device 1. Further, the gateway device 3 transmits the number of time resource requests for each of the periodic detection sensor data and the event-driven detection sensor data to the data aggregation device 1, and the data aggregation device 1 assigns the time resource to each. Then, the schedule table including the respective allocation results is transmitted to the gateway device 3.

(Detailed equipment configuration)
Hereinafter, the apparatus configuration in the present embodiment will be described in detail.

  FIG. 5 shows a functional block diagram of the gateway device 3. As illustrated in FIG. 5, the gateway device 3 includes a sensor data receiving unit 31, a sensor data queuing unit 32, a sensor data queue 35 including an event-driven detection sensor data queue 33 and a periodic detection sensor data queue 34, a sensor Data queue monitoring unit 36, normal time resource request count calculation unit 37, emergency time resource request count calculation unit 38, schedule table reference unit 39, sensor data transfer unit 40, management data transfer unit 41, individual schedule table / emergency allocation time resource A table receiving unit 42, an individual schedule table, and a schedule table storage unit 43 for storing an emergency data allocation time resource table are provided. The operation is as follows.

  The sensor data receiving unit 31 receives sensor data from a subordinate wireless sensor network. Then, the sensor data queuing unit 32 refers to the correspondence table shown in FIG. 4 stored in the storage device, determines the sensor data type of the received sensor data, and stores the sensor data in the queue corresponding to the sensor data type. Accumulate.

  Then, the schedule table reference unit 39 refers to the individual schedule table and the urgent data allocation time resource table and issues an instruction to the sensor data transfer unit 40 according to the allocation time resource information described in the table. In accordance with the instruction, the sensor data is read from the queue and transferred to the data aggregating apparatus 1. As will be described later, the individual schedule table includes time resource information for sending the number of time resource requests (referred to as management data), and the schedule table reference unit 39 refers to this information. The management data transfer unit 41 is instructed, and the management data transfer unit 41 transfers the number of time resource requests calculated by the normal time resource request number calculation unit 37 and the emergency time resource request number calculation unit 38 according to this instruction. .

  In addition, the sensor data queue monitoring unit 36 monitors each of the periodic detection sensor data queue and the event-driven detection sensor data queue, and the monitoring result is calculated as a normal time resource request number calculation unit 37 and an emergency time resource request number calculation. Pass to part 38. As shown in FIG. 5, the data passed to the normal time resource request count calculation unit 37 is the number of unused time slots and the number of timeout data bytes, and the data passed to the emergency time resource request count calculation unit 38 is , Buffer usage rate, etc. The normal time resource request number calculation unit 37 and the emergency time resource request number calculation unit 38 each calculate the number of time resource requests using this data.

  Each processing function unit of the gateway device 3 can be realized by mounting a program for executing processing described in the present embodiment on a computer including a storage device such as a CPU, a memory, and a hard disk. The queue can be realized by using a memory, and the schedule table storage unit 43 can be realized by a memory or a hard disk.

  Next, a functional block diagram of the data aggregation device 1 is shown in FIG. As shown in FIG. 6, the data aggregation device 1 includes a sensor data receiving unit 11, a sensor data storage unit 12, a management data receiving unit 13, a requested time resource allocation availability determination unit 14, an emergency allocation time resource table generation unit 15, an individual The schedule table generating unit 16, the individual schedule table transmitting unit 17, and the emergency allocation time resource table transmitting unit 18 are included. The operation is as follows.

  The sensor data receiving unit 11 stores the sensor data received from the gateway device 3 in the sensor data storage unit 12. The sensor data stored in the sensor data storage unit 12 is used for processing for abnormality notification or the like, but since this processing itself can be realized using conventional technology, a functional unit that performs this processing is not shown. Absent.

  In addition, the management data receiving unit 13 receives the number of normal time resource requests or the number of emergency time resource requests from the gateway device 3, and sends this to the request time resource allocation determination unit 14. The requested time resource allocation determination unit 14 allocates time resources to time slots from the number of normal time resource requests or the number of emergency time resource requests, and determines whether this allocation is possible in the entire time resources. If possible, the allocation result information is sent to the urgent allocation time resource table generation unit 15 or the individual schedule table generation unit 16, and these are sent to the emergency allocation time resource table transmission unit 18 and the individual schedule table transmission unit 17, respectively. Requesting transmission, the emergency allocation time resource 18 table notification unit and the individual schedule table transmission unit 17 transmit the tables to the gateway device 3 respectively.

  Each processing function unit of the data aggregating apparatus 1 can also be realized by mounting a program for executing processing described in the present embodiment on a computer including a storage device such as a CPU, a memory, and a hard disk.

(About time resource allocation)
In the present embodiment, as time resource allocation in the data aggregation device 1, normal time resource allocation, emergency time resource allocation, and time resource allocation for management data are performed. Hereinafter, these will be described in detail.

  First, the difference between the roles of normal time resource allocation and emergency time resource allocation will be described with reference to FIG.

  As shown in FIG. 7A, the data amount of the sensor data may suddenly increase while changing relatively slowly along the time axis.

  As shown in FIG. 7B, the normal time resource allocation is performed for the purpose of following data that changes relatively slowly along the time axis. For example, in the case of periodic detection sensor data, small fluctuations as shown in FIG. 7B occur due to an increase or decrease in the number of target sensor nodes connected to each gateway device, and in event-driven detection sensor data, It is assumed that it occurs due to the increase or decrease in the number of sensor nodes and the occurrence of local events.

  On the other hand, the emergency time resource allocation temporarily allocates time resources as shown in FIG. 7 (c) for the purpose of following a sudden change in data amount as shown in FIG. 7 (a). is there. As shown in FIG. 7 (a), for example, in the event-driven detection sensor data, a large-scale event occurs in which many sensors perform sensing detection. Etc.).

  Next, management data time resource allocation in each of normal time resource allocation and emergency time resource allocation will be described.

  The normal time resource allocation is performed for each sensor data type according to a predetermined cycle (referred to as a rescheduling cycle). For example, for a schedule unit period of 1 minute, the rescheduling cycle interval is 5 minutes. In this case, every time the sensor data allocation time resource table (see FIG. 2) is referenced five times, the sensor data allocation time resource table is updated to a new sensor data allocation time resource table.

  Therefore, the management data time resource used for normal time resource allocation is allocated every rescheduling cycle interval (every 5 minutes in the previous example). Each gateway device 3 notifies the data aggregation device 1 of the number of time resource requests at the time resource allocation timing, and the data aggregation device 1 reallocates the time resources.

  When allocating management data time resources normally used for allocating time resources, each gateway device is used in order to avoid the reassignment processing for the plurality of gateway devices overlapping at a specific time slot time between the plurality of gateway devices. The allocation of time resources for management data in is appropriately distributed.

  For example, when the gateway device 3 is initially connected, the first management data time resource is assigned by specifying a random time slot number, and the subsequent management data time resource assignment is in accordance with the set re-schedule cycle interval. I will do it. Thereby, for example, it is possible to avoid a situation in which many gateway devices simultaneously transmit the number of normal time slot requests to the data aggregation device 1 at the same time slot number every time. Furthermore, a management data allocation time resource management table for each gateway device as shown in FIG. 8 may be provided in the data aggregation device 1, and management data time resources may be allocated based on the table. In this table, a time slot number assigned for management data transmission in association with each gateway device is recorded. In this embodiment, since the reassignment is performed every time the schedule unit period elapses five times, the time when the time slot is first assigned to manage the assignment within the schedule unit period repeated five times. Is also recorded.

  On the other hand, emergency time resource allocation is not performed periodically as in normal time resource allocation, but is performed so as to follow suddenly changed sensor data.

  Therefore, the management data time resource allocation cycle interval used for urgent time resource allocation is set based on the system allowable time required to follow a sudden change in the sensor data amount.

  For example, if it is desired to complete the time resource assignment for the data within 20 seconds in response to a sudden change in the sensor data amount, the time resource assignment period for the management data used for the emergency time resource assignment The interval is set to 20 seconds (allocation of 3 time resources per minute of the schedule unit period).

  As described above, a total of five time resources are allocated to each gateway device 3, two as normal time resources for sensor data, one as emergency time resources, and two for management data. Of these, the individual schedule table is a combination of the management data allocation time resource table indicating the management data time resource allocation and the sensor data allocation time resource table indicating the sensor data normal time resource allocation. There is an emergency allocation time resource table showing allocation of emergency time resources. An example of the individual schedule table is shown in FIG. 9, and an example of the emergency allocation time resource table is shown in FIG.

  FIG. 11 shows a time-series image of time resource allocation. 11A to 11E indicate a schedule unit period. In normal time resource allocation, the number of time resource requests is sent from the gateway apparatus 3 every time this period is repeated five times, and the data aggregation apparatus. In 1, new time resource allocation is performed.

  As shown in FIG. 11C, at time T1, allocation of five time resources for the periodic detection sensor data and two time resources for the event-driven detection sensor data are requested, and accordingly, FIG. a) and time resources are allocated as shown in FIG. At time T2, five time resources are requested for the periodic detection sensor data and two time resources are assigned for the event-driven detection sensor data, and time resource assignment is performed accordingly.

  Further, FIG. 11D shows a management data time resource for urgent time resource allocation. As shown in this figure, an event requiring an urgent time resource occurs between T3 and T4. At time T4, five emergency time resource allocation requests are made. Accordingly, as shown in FIG. 11 (e), five emergency time resources are allocated. Further, at time T5, three emergency time resource allocation requests are made, and emergency time resources according to the request are allocated. As shown in FIG. 11 (e), the emergency time resource is effective only in the schedule unit period to which it is assigned.

  Each time resource is basically used only for transferring the corresponding data type. However, for example, when the periodic detection sensor data to be transmitted is not queued at the allocation time resource timing for periodic detection sensor data, or when the management data time resource is used for urgent time resource allocation. When the request for the emergency time resource is not required at the timing, the sensor data or the management data other than the original transmission purpose may be transferred using the time resource. Next, processing in each time resource allocation in normal time and emergency will be described in detail.

(Individual schedule table creation and distribution processing)
First, an individual schedule table creation and distribution process in normal time is shown in FIG. 12 (step 1) queue usage status monitoring, (step 2) time resource request count calculation, (step 3) individual schedule table creation and distribution procedure It explains along.

<S1: Queue usage status monitoring>
The gateway device 3 monitors the use status of the queue for each of the periodic detection sensor data queue and the event-driven detection sensor data queue. Specifically, the number of unused time resources and the number of timeout data bytes in the queue from the previous rescheduling timing to the current rescheduling timing are counted.

  The number of unused time resources is the number of times that the timing is not used for data transmission because there is no data to be transmitted to the queue at the time resource allocation timing shown in the schedule table. The number of timeout data bytes is the total number of bytes of sensor data queued in the queue for a predetermined time (for example, a schedule unit period).

  If the number of unused time resources is large, it indicates that the current number of allocated time resources is excessive, which reduces the number of new time resource allocation requests. If the number of time-out data bytes is large, the number of currently allocated time resources In order to show that is not enough, it becomes a factor to increase the number of requests.

<S2: Time resource request count calculation>
The gateway device 3 calculates the number of time resource requests from the above two parameters at the rescheduling timing (= management data time resource allocation timing for normal time resource allocation), and transfers it to the data aggregation device 1.

  For example, when the rescheduling cycle interval is 5 minutes, the schedule unit period is 1 minute, and the maximum number of transmission bytes per time resource is 50 bytes, the time resource request count is calculated based on the previous time resource request count. Then, it is calculated by the following formula.

Time resource request count = previous allocation request count
+ (Number of timeout data bytes / 50)
-(Time resource unused number / 5)
Here, the second term of the above formula is that the number of time resources per schedule unit period required to transmit time-out data is calculated by dividing the number of time-out data bytes by the number of transmission bytes per unit time resource. This term is a term to be calculated, and this term is a term to increase the number of time resource requests. The third term is a term in which the number of unused time resources per schedule unit period is calculated by dividing the number of unused time resources by the number of schedule unit periods per rescheduling cycle interval. This is a term that reduces the number of requests.

  An example of the time resource request count calculation is shown in FIG. In the example shown in FIG. 13, the maximum transmission bandwidth per unit time resource is 50 bytes, the schedule unit period is 1 minute (24 slots per schedule unit period), and the rescheduling cycle interval is 5 minutes. In this example, the amount of time-out data is 200 bytes and the number of unused time resources is 0.

  As shown in FIG. 13, when the number of time resource requests at the previous time (at time T1) is 5, from the above formula, 5+ (200/50) − (0/5) = 9, and the next time (at T2 The number of time resource requests at the time) is 9. Then, through the following individual schedule table creation and distribution, time resources after T2 are allocated, and sensor data is transferred according to the time resources.

<S3: Individual schedule creation and distribution>
The data aggregating apparatus 1 creates a temporary individual schedule table based on the number of time resource requests received from the gateway apparatus 3. Time resource allocation for creating a provisional individual schedule table is performed at equal intervals within a schedule unit period in order to maximize a transmission opportunity for generation of sensor data that is difficult to predict. This allocation includes the management data time resource allocation described above.

  For example, when the unit time resource time is 2.5 seconds and the schedule unit period is 1 minute, the schedule unit period is divided into 24 time slots. At this time, when 3 is received as the number of time resource requests, 8 hours Allocation is performed for each slot. At this time, the initial position for time resource allocation is determined randomly in order to avoid duplication and bias of allocated time resources in a specific time slot number between a plurality of gateway devices.

  In the above example, when the time resource allocation initial time slot position is determined to be 12, the unit time resource is allocated in the 4th, 12th, and 20th time slots. By assigning time resources from such random initial time slot positions, the number of assigned time resources for each time resource in the entire schedule can be made uniform.

  However, particularly in the time resource allocation for periodic sensor data, when the sensing timing within the schedule unit period can be predicted in advance, the allocation may be performed accordingly.

Subsequently, the data aggregating apparatus 1 determines whether or not the created provisional individual schedule table can actually be assigned. Specifically, the data aggregating apparatus 1 manages an overall schedule table in which individual schedule tables for all gateway apparatuses 3 are aggregated, and the newly created individual schedule table is reflected in the overall schedule table.
An example of the entire schedule table is shown in FIG. As shown in FIG. 14, the overall schedule table manages the number of time resources allocated to all gateway devices 3 in each time slot within the schedule unit period. For each allocation unit time resource in each time slot number, An ID that uniquely identifies the allocation target gateway device 3 is associated and managed. As a result, the time resource table assigned to each gateway device 3 can be extracted from the entire schedule table. In addition to the gateway device ID, information for identifying the use of the allocated time resource (for sensor data, management data, emergency data, etc.) may be added as necessary.

  As a result of reflecting the newly generated individual schedule table in the overall schedule table, check whether the number of allocated time resources in each time slot exceeds the maximum number of allocatable time resources determined from the maximum bandwidth in the access network. . If assignment is possible, the temporary individual schedule table is distributed to the gateway device as a new individual schedule table.

  If the allocation cannot be performed because the maximum number of time resources is exceeded, the gateway device 3 is notified that the allocation is impossible. Alternatively, a temporary schedule table may be created again by changing the initial value of assignment, and it may be determined whether assignment is possible.

(Creation of emergency allocation time resource table, distribution process)
Next, the emergency allocation time resource table creation and distribution processing in an emergency is shown in FIG. 15 (step 11) queue usage status monitoring, (step 12) time resource request count calculation, (step 13) emergency allocation time resource table It explains along the procedure of creation and distribution. FIG. 16 shows timing examples and allocation examples of (step 11) queue usage status monitoring, (step 12) time resource request count calculation, (step 13) emergency allocation time resource table creation, and distribution. .

<S11: Queue usage status monitoring>
The gateway device 3 monitors whether there is no data that needs to be transmitted urgently and detects the occurrence of each of the periodic detection sensor data queue and the event-driven detection sensor data queue. Specifically, it is monitored whether the buffer free capacity of the queue is not less than a predetermined threshold, for example, whether the buffer free capacity is less than 50% of the total, and if it is below, It is determined that data that needs to be transmitted has occurred.

<S12: Time resource request count calculation>
When the gateway device 3 determines that data that needs to be urgently transmitted (referred to as urgent data) has occurred in a certain queue, the gateway device 3 uses an emergency time resource that is the number of time resources necessary for transmission of the urgent data. After calculating the number of requests, the data aggregation device 1 is notified.

  As the number of emergency time resource requests, a value statically set by each gateway device 3 or a value dynamically calculated according to the free capacity of the buffer is used. For example, if 470 bytes of data are stacked in the corresponding queue and the batch data is sent urgently due to a decrease in the free space of the buffer, the maximum amount of transmission data per unit time resource is 50 bytes. If there is, 10 is transmitted to the data aggregation device 1 as the number of emergency time resource requests.

<S13: Emergency allocation time resource table creation and distribution>
The data aggregating apparatus 1 uses the time resource of the number of emergency time resource requests received from the gateway apparatus 3 as the emergency time resource for the gateway apparatus 3, and the latest time slot number (for example, three time slots ahead of the current time slot). ). For example, when 10 emergency time resources are allocated, 10 time resources are allocated in 3 time slots according to the status of the entire schedule table, or 5 times are allocated to 3 and 4 time slots. Allocation such as resource allocation is performed.
Also, as a result of referring to the entire schedule table, if there is no free time resource that can be allocated with the most recent time slot number, an emergency time resource is created after temporarily deleting part of the normal time resource. May be assigned.

  The data aggregation device 1 notifies the gateway device 3 of the emergency time resource allocated as described above. This emergency time resource allocation is temporary that can be used only once in the designated time resource time, and the allocated emergency time resource cannot be used within the next schedule unit period.

(Effects of the system described in this embodiment)
In the system of the present embodiment, each gateway device 3 periodically calculates the number of time resource requests according to the usage status of its own queue, so that it is flexible to fluctuations in the amount of sensor data generated in each gateway device 3. It is possible.

  In addition, since time resources are allocated for each data type, appropriate time resource allocation according to data characteristics can be performed. In addition, rescheduling based on the queue usage status is performed periodically, emergency data generation is monitored, and emergency time resources are allocated when emergency data occurs. It is possible to cope with both fluctuations and a sudden increase in the amount of sensor data within a short time.

  In addition, since each gateway device 3 autonomously calculates the number of time resource requests with the largest processing load, the load on the data aggregation device 1 is reduced.

  The present invention is not limited to the above-described embodiments, and various modifications and applications are possible within the scope of the claims. In this embodiment, an example is shown in which the present invention is applied to an aggregation system that aggregates sensor data transmitted from sensors. However, the present invention is not limited to sensor data aggregation, and is transmitted from a plurality of data transmission apparatuses. The present invention can be applied to any data as long as it is a system that aggregates the data to be collected via the gateway device.

It is a system configuration figure in an embodiment of the invention. It is a figure for demonstrating the example which transmits sensor data according to the allocation time resource. It is a figure for demonstrating the operation | movement outline | summary of the system in the case of performing sensor data transfer using two queues. It is a figure which shows the example of the correspondence table which matched ID of a sensor, and the data classification transmitted. 3 is a functional block diagram of a gateway device 3. FIG. 3 is a functional block diagram of the data aggregation device 1. FIG. It is a figure for demonstrating the role of normal time resource allocation and emergency time resource allocation. It is a figure which shows the allocation time resource management table for management data. It is a figure which shows an example of an individual schedule table | surface. It is a figure which shows an example of an emergency allocation time resource table | surface. It is a figure which shows the mode of allocation of a time resource by a time series image. It is a figure for demonstrating preparation of an individual schedule table, and a delivery process. It is a figure for demonstrating an example of time resource request number calculation. It is a figure which shows the example of a whole schedule table | surface. It is a figure for demonstrating preparation of an emergency allocation time resource table | surface, and a delivery process. It is a figure for demonstrating preparation of an emergency allocation time resource table | surface, and a delivery process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Data aggregation apparatus 2 Network 3 Gateway apparatus 11 Sensor data receiving part 12 Sensor data storage part 13 Management data receiving part 14 Request time resource allocation availability determination part 15 Emergency allocation time resource table generation part 16 Individual schedule table generation part 17 Individual schedule table Transmission unit 18 Emergency allocation time resource table transmission unit 31 Sensor data reception unit 32 Sensor data queuing unit 33 Event-driven detection sensor data queue 34 Periodic detection sensor data queue 35 Sensor data queue 36 Sensor data queue monitoring unit 37 Normal time resource Request number calculation unit 38 Urgent time resource request number calculation unit 39 Schedule table reference unit 40 Sensor data transfer unit 41 Management data transfer unit 42 Individual schedule table / emergency allocation time resource table reception Part 43 schedule table storage unit 43

Claims (14)

The gateway in a data aggregation system comprising a plurality of gateway devices for receiving data transmitted from a plurality of data transmission devices, and further comprising a data aggregation device for aggregating data of the data transmission devices transmitted from the plurality of gateway devices A device,
A queue buffer for temporarily storing data received from the data transmission device as a queue;
Transmission resource allocation table storage means for storing a transmission resource allocation table including time slot information indicating the timing for transmitting the data accumulated in the queue buffer to the data aggregation device and transmission data amount information at the transmission timing;
With reference to the transmission resource allocation table stored in the transmission resource allocation table storage means, based on the time slot information and the transmission data amount information indicated in the transmission resource allocation table, the queue buffer transfers the data aggregation device. Data transmission means for transmitting data;
The state of the queue buffer is monitored, a transmission resource requirement is determined based on the state, the transmission resource requirement is transmitted to the data aggregation device, and the data aggregation device is transmitted in response to the transmission resource requirement being transmitted. And a transmission resource allocation table updating unit that stores the transmission resource allocation table received from the transmission resource allocation table in the transmission resource allocation table storage unit instead of the existing transmission resource allocation table.   The gateway apparatus according to claim 1, wherein the transmission resource allocation table update unit updates the transmission resource allocation table by periodically transmitting the transmission resource required amount to the data aggregation apparatus.   The transmission resource allocation table updating means is configured to perform a count between a number of times that no data exists in the queue buffer at a transmission timing indicated by the time slot information within a predetermined period and a time that is predetermined in the queue buffer. The gateway apparatus according to claim 2, wherein the required transmission resource amount is determined from the accumulated data amount.   The transmission resource allocation table updating means updates the transmission resource allocation table by transmitting the required amount of transmission resources to the data aggregation device when the queue buffer is in a predetermined state. The gateway device according to claim 1 or 2.   The gateway device according to claim 4, wherein the predetermined state is that a free capacity of the queue buffer is equal to or less than a predetermined amount. The plurality of data transmission devices include a periodic data transmission device that periodically transmits data and an event-driven data transmission device that transmits data in response to occurrence of a specific event,
The gateway device includes, as the queue buffer, a periodic data queue buffer for accumulating periodic data that is data transmitted from the periodic data transmitting device, and an event that is data transmitted from the event-driven data transmitting device. An event-driven data queue buffer for storing drive-type data,
The transmission resource allocation table storage unit stores a transmission resource allocation table for each of the periodic data queue buffer and the event-driven data queue buffer, and the data transmission unit allocates a transmission resource to each queue buffer. The data transmission with reference to a table is performed, and the transmission resource allocation table update unit updates the transmission resource allocation table for each queue buffer. Gateway device. The data in a data aggregation system comprising a plurality of gateway devices for receiving data transmitted from a plurality of data transmission devices, and further comprising a data aggregation device for aggregating data of the data transmission devices transmitted from the plurality of gateway devices An aggregation device,
Receiving a transmission resource requirement from the gateway device, and based on the transmission resource requirement, time slot information indicating a timing at which the gateway device transmits the data to the data aggregation device, and transmission data amount information at a transmission timing; A transmission resource allocation table creating means for creating a transmission resource allocation table including
Means for transmitting the transmission resource allocation table to the gateway device that has transmitted the required amount of transmission resources.   8. The data aggregation device according to claim 7, wherein the transmission resource allocation table includes time slot information and transmission data amount information allocated for the gateway device to transmit the transmission resource required amount.   The time slot information assigned by the gateway device to transmit the transmission resource requirement amount includes information on a first time slot used by the gateway device to transmit the transmission resource requirement amount periodically, and the gateway Including information on the second time slot used to transmit the transmission resource requirement when the apparatus detects a predetermined state, and the time interval of the second time slot is the time interval of the first time slot The data aggregation device according to claim 8, wherein the data aggregation device is smaller.   The data aggregating apparatus has an overall transmission resource allocation table including transmission data amount information allocated for each time slot for all subordinate gateway apparatuses, and the transmission resource allocation table creating means includes the overall transmission resource allocation 10. The data aggregation device according to claim 7, wherein whether or not transmission resources can be assigned to the specific gateway device is determined with reference to a table. 11. A data aggregation system comprising a plurality of gateway devices for receiving data transmitted from a plurality of data transmission devices, and further comprising a data aggregation device for aggregating data of the data transmission devices transmitted from the plurality of gateway devices. ,
The gateway device is
A queue buffer for temporarily storing data received from the data transmission device as a queue;
Transmission resource allocation table storage means for storing a transmission resource allocation table including time slot information indicating the timing for transmitting the data accumulated in the queue buffer to the data aggregation device and transmission data amount information at the transmission timing;
With reference to the transmission resource allocation table stored in the transmission resource allocation table storage means, based on the time slot information and the transmission data amount information indicated in the transmission resource allocation table, the queue buffer transfers the data aggregation device. Data transmission means for transmitting data;
The state of the queue buffer is monitored, a transmission resource requirement is determined based on the state, the transmission resource requirement is transmitted to the data aggregation device, and the data aggregation device is transmitted in response to the transmission resource requirement being transmitted. A transmission resource allocation table that is received from the transmission resource allocation table update unit that stores the transmission resource allocation table in the transmission resource allocation table storage unit instead of the existing transmission resource allocation table,
The data aggregation device includes:
A transmission resource allocation table creating means for receiving a transmission resource requirement from the gateway device and creating the transmission resource allocation table based on the transmission resource requirement;
A data aggregation system comprising: means for transmitting the transmission resource allocation table to the gateway device that has transmitted the required amount of transmission resources. Executed by a data aggregation system comprising a plurality of gateway devices for receiving data transmitted from a plurality of data transmission devices, and further comprising a data aggregation device for aggregating data of the data transmission devices transmitted from the plurality of gateway devices. A data transmission method,
Time slot information and transmission timing indicating the timing at which the gateway device temporarily accumulates data received from the data transmission device as a queue in a queue buffer and transmits the data accumulated in the queue buffer to the data aggregation device Read the transmission resource allocation table from the transmission resource allocation table storage means for storing the transmission resource allocation table including the transmission data amount information at the time, and refer to the transmission resource allocation table to determine the time indicated in the transmission resource allocation table. Based on the slot information and transmission data amount information, the data is transmitted from the queue buffer to the data aggregation device,
The gateway device monitors the state of the queue buffer, determines a transmission resource requirement based on the state, and transmits the transmission resource requirement to the data aggregation device;
The data aggregation device receives a transmission resource requirement from the gateway device, creates a transmission resource allocation table based on the transmission resource requirement, and transmits the transmission resource requirement to the transmission resource allocation table. To the gateway device,
The gateway apparatus stores the transmission resource allocation table received from the data aggregating apparatus in the transmission resource allocation table storage means in place of the existing transmission resource allocation table. The gateway in a data aggregation system comprising a plurality of gateway devices for receiving data transmitted from a plurality of data transmission devices, and further comprising a data aggregation device for aggregating data of the data transmission devices transmitted from the plurality of gateway devices A gateway device comprising a queue buffer for temporarily storing data received from the data transmission device as a queue,
The transmission in the transmission resource allocation table storage means for storing a transmission resource allocation table including time slot information indicating the timing for transmitting the data accumulated in the queue buffer to the data aggregation device and transmission data amount information at the transmission timing Means to reference the resource allocation table,
Data transmission means for transmitting data from the queue buffer to the data aggregation device based on the time slot information and transmission data amount information indicated in the transmission resource allocation table;
The state of the queue buffer is monitored, a transmission resource requirement is determined based on the state, the transmission resource requirement is transmitted to the data aggregation device, and the data aggregation device is transmitted in response to the transmission resource requirement being transmitted. A transmission resource allocation table updating unit for storing the transmission resource allocation table received from the transmission resource allocation table storage unit instead of the existing transmission resource allocation table;
Program to function as. The data in a data aggregation system comprising a plurality of gateway devices for receiving data transmitted from a plurality of data transmission devices, and further comprising a data aggregation device for aggregating data of the data transmission devices transmitted from the plurality of gateway devices Aggregator
Receiving a transmission resource requirement from the gateway device, and based on the transmission resource requirement, time slot information indicating a timing at which the gateway device transmits the data to the data aggregation device, and transmission data amount information at a transmission timing; A transmission resource allocation table creating means for creating a transmission resource allocation table including
Means for transmitting the transmission resource allocation table to the gateway device that has transmitted the required amount of transmission resources;
Program to function as.

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