WO2014136401A1

WO2014136401A1 - Dynamically controlling sensors

Info

Publication number: WO2014136401A1
Application number: PCT/JP2014/000996
Authority: WO
Inventors: Sivabalan ARUMUGAM; Anand Raghawa Prasad
Original assignee: Nec Corporation
Priority date: 2013-03-04
Filing date: 2014-02-26
Publication date: 2014-09-12

Abstract

A sensor system includes a plurality of sensors (100) and a higher layer device of the sensor. The sensor (100) includes a receiving part (101) that receives a control signal having at least one control command. The control signal is sent from the higher layer device. The sensor further includes a sensing part (103) that senses sensor data with at least one configuration parameter dynamically set by the control command included in the control signal. The control signal may include at least one of a frequency control command and an accuracy control command.

Description

[Title established by the ISA under Rule 37.2] DYNAMICALLY CONTROLLING SENSORS

This invention is related to a sensor, a sensor system, a method of controlling at least one of a plurality of sensors included in a sensor system, an interface used for a sensor system and a method of controlling a sensor system including a plurality of sensors and a higher layer device controlling the plurality of the sensors, more specifically, to a sensor, a sensor system, a method of controlling at least one of a plurality of sensors included in a sensor system, an interface used for a sensor system and a method of controlling a sensor system used for collecting, for example, temperature data or humidity data in an environment.

During the last two decade, there has been a momentous growth in Sensor Networks that makes it potentially suitable for use in environment monitoring and process control application. Data collection and management are the two critical processes in the sensor network applications.

Fig. 1 shows the sensor network architecture which consists of sensor (wired as well as wireless), gateway (wireless as well as wired), network server and the application unit in the Related Art. As shown in Fig. 1, a sensor network system 1000 includes a plurality of sensors 1100, a gateway 1200, a network infrastructure 1210, a network service provider 1220, and an application 1300. The application 1300 or the network service provider 1220 collects sensor data from the plurality of the sensors 1100 through the gateway 1200 and the network infrastructure 1210. Most of the Related Arts manage the data at the gateway level.

NPL 1: Energy-Efficient Data Management For Sensor Networks: A Work-In-Progress Report Alan Demers, Johannes Gehrke, Rajmohan Rajaraman, Niki Trigoni, and Yong Yao,Department of Computer Science, Cornell University, Ithaca, NY 14853
(http://www.cs.ox.ac.uk/sensors/publications/Demers_UpstateNYWorkshop2003.pdf)
NPL 2: Energy Efficient Data Management for Wireless Sensor Networks with Data Sink Failure, Hyunyoung Lee, Andreas Klappenecker, Kyungsook Lee, Lan Lin in Proceedings of the Workshop on Resource Provisioning and Management in Sensor Networks, Nov. 2005
(http://faculty.cse.tamu.edu/hlee/Research/RPMSN05.pdf)
NPL 3: Efficient Data Collection with Sampling in WSNs: Making Use of Matrix Completion Techniques Jie Cheng,Hongbo Jiang,Xiaoqiang Ma,Lanchao Liu, Lijun Qian, Chen Tian, and Wenyu Liu, Huazhong University of Science and Technology, Wuhan 430074 China, IEEE Globecom 2010 proceedings
NPL 4: DATA GATHERING ALGORITHMS FOR WIRELESS SENSOR NETWORKS: A SURVEY K.Ramanan and E.Baburaj, Sun college of Engineering and Technology, Nagercoil. International Journal of Ad hoc, Sensor and Ubiquitous Computing (IJASUC) Vol.1, No.4, December 2010
NPL 5: Abughalieh, Nashat Le Borgne, Yann-Ael Steenhaut, Kris Nowe, Lifetime optimization for wireless sensor networks with correlated data gathering, Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks (WiOpt), 2010 Proceedings of the 8th International Symposium on Issue Date : May 31 2010-June 4 2010 On page(s): 266 272.
NPL 6: Ayman Mohammd Brisha Classifying Sensors Depending on their IDs to Reduce Power Consumption in Wireless Sensor Networks 2010, International Journal of Online Engineering ,Vol: 6 Issue: 2 Pages/record No.: 41-45.
NPL 7: Ayon Chakraborty ; Kaushik Chakraborty ; Swarup Kumar Mitra ; Mrinal K. Naskar , An energy efficient scheme for data gathering in wireless sensor networks using particle swarm optimization 2009,Journal of Applied Computer Science and Mathematics ,Vol: 3 Issue: 6 Pages/record No.: 9-13.
NPL 8: B.Amutha ; M. Ponnavaikko ; N.Karthick ; M.Saravanan, Localization Algorithm Using Varying Speed Mobile Sink for Wireless Sensor Networks 2010 International Journal of Ad Hoc, Sensor and Ubiquitous Computing, Issn: 09762205, EIssn: 09761764, Volume: 1, Issue: 3, pages/rec.No: 130-149.
NPL 9: Chiu-Kuo Liang Jian-Da Lin Chih-Shiuan Li ,Steiner Points Routing Protocol for Wireless Sensor Networks, in Future Information Technology (FutureTech), 2010 5th International Conference on IssueMay2010 On page(s): 1 5,Busan.
NPL 10: M. Demirbas, A. Arora, and V. Mittal. FLOC: A fast local clustering service for wireless sensor networks. Workshop on Dependability Issues in Wireless Ad Hoc Networks and Sensor Networks (DIWANS/DSN), 2004.
NPL 11: Yi-hua Zhu , Wan-deng Wu, Jian Pan , Yi- ping Tang, "An energy-efficient data gathering algorithm to prolong lifetime of wireless sensor networks", Original Research Article, Computer Communications, Volume 33, Issue 5, 15March2010,Pages639-647.
NPL 12: Hoang, D.C. Yadav, P. Kumar, R. Panda, S.K, "A Robust Harmony Search Algorithm Based Clustering Protocol for Wireless Sensor Networks", Communications Workshops (ICC), 2010 IEEE International Conference on ,Issue Date : 23-27 May 2010 On page(s): 1 - 5.
NPL 13: Ying Liang, "An energy-efficient clustering algorithm for data gathering and aggregation in sensor networks" , Industrial Electronics and Applications, 2009. ICIEA 2009. 4th IEEE Conference on 25-27, May2009, 3935-3939.
NPL 14: Lingyun Yuan Yunlong Zhu Tianwei Xu, "A Multi-Layered Energy-Efficient and Delay-Reduced Chain-Based Data Gathering Protocol for Wireless Sensor Network", : Mechtronic and Embedded Systems and Applications, 2008. MESA 2008. IEEE/ASME International Conference on Issue Date : 12-15 Oct. 2008 On page(s): 13 - 18.
NPL 15: Narang, Sunil K Shen, Godwin Ortega, Antonio, Unidirectional graph-based wavelet transforms for efficient data gathering in sensor networks, Acoustics Speech and Signal Processing (ICASSP), 2010 IEEE International Conference on Issue Date: 14-19March2010 On page(s): 2902 - 2905.
NPL 16: Wang, Zheng Liu, Yunsheng, "Data gathering routing algorithm based on energy level in wireless sensor networks", Future Computer and Communication (ICFCC), 2010 2nd International Conference on IssueDate 21-24May2010 Volume : 2 ,On page(s): V2-160 - V2-164.
NPL 17: Junbin Liang Jianxin Wang Jianer Chen," A Delay-Constrained and Maximum Lifetime Data Gathering Algorithm for Wireless Sensor Networks", Mobile Ad-hoc and Sensor Networks, 2009. MSN '09. 5th International Conference on Issue Date : 14 16 Dec. 2009 On page(s): 148 - 155.
NPL 18: Soyoung Hwang Gwang-Ja Jin Changsub Shin Bongsoo Kim," Energy-Aware Data Gathering in Wireless Sensor Networks",Consumer Communications and Networking Conference, 2009. CCNC 2009. 6th IEEE Issue Date : 10-13Jan.2009 On page(s): 1 - 4.
NPL 19: Yang, Jing Zetao Li Yi Lin Wei Zhao, "A novel energy-efficient data gathering algorithm for wireless sensor networks", Intelligent Control and Automation (WCICA), 2010 8th World Congress on IssueDate: 7-9July2010 On page(s): 7016 - 7020.

The drawbacks of the sensor network implementation in the Related Arts are as follows. Firstly, the sensor network implementation in the Related Art has preconfigured sensor nodes which collect and send the data continuously in predefined interval from the field. Due to network characteristics there is a limitation in the transmission bandwidth which leads to network congestion and also data loss.

Consider a temperature monitoring system, if a sensor sends data periodically every one second, the amount of data would be around 2.5 million Tera byte/month. This number increases exponentially, as the number of the sensor grows for the enterprise level network.

Secondly, the sensor nodes in the Related Art do not have built-in intelligence, which behave the same way irrespective of the working environment. That is, sensor nodes have pre-configured sampling rate such as the number of sample per second and predefined accuracy such as the number of bits per sample.

Consider an example where sensors are deployed to monitor the temperature of boilers in the industry environment. These temperature sensors are preconfigured with fixed sampling rate and fixed resolution. In this application the 2 minutes sampling interval with the accuracy of 8 bits per sample, which means the sensor would sense data and send to access network gateway periodically at every 2 minutes interval with the accuracy of 8 bits per sample. If there occurs some emergency situation, due to some issue in the boiler output which in-turn exponentially raises the boiler temperature, the difference in the actual sample value between two successive samples is very high.

However, if the sensor system prepares for such an issue, the number of the sampling rate and the accuracy of the samples are set large, and the amount of data increases too much. Redundant data flow in the network, which introduces more traffic as well as congestion in the network. On the other hand, if the number of the sampling rate and the accuracy of the samples are set small, the application 1300 cannot collect the necessary data used for, for example, monitoring the environment.

Further, there are various ways to collect and manage data discussed in the literature such as Energy-efficient Routing Algorithm to Prolong Lifetime [NPL 11], Harmony Search Algorithm (HSA) [NPL 12], Novel clustering algorithm OCABTR [NPL 13], Multi-Layer Energy-Efficient And Delay-Reducing Chain-Based Data Gathering Protocol [NPL 14], Steiner Points Grid Routing [NPL 15], Data Gathering Algorithm Based on Energy Level( DGEL) [NPL 16], Energy-efficient and Delay-aware Data Gathering Protocol [NPL 17], Energy-Efficient Data Gathering Protocol (EEDGP) [NPL 18], and Energy-efficient data gathering algorithm(EDGA) [NPL 19]. However, there exists still heavy data traffic below the gateway level where there is lack of available bandwidth in case of wireless sensor network. Currently no mechanism exists that can introduce dynamic behavior in the sensor data collection.

Therefore there is need of data management below the gateway so as to maximize the bandwidth utilization as well as the energy efficiency, which increases the life time of the sensor nodes.

The present invention have been made to solve the problem like this, and an object thereof is to provide a sensor, a sensor system and a method of controlling a sensor system that can dynamically tune a configuration parameter of sensor data.

In one embodiment, there is provided a sensor which is used for a sensor system including a plurality of sensors and a higher layer device of the sensor, including: a receiving part that receives a control signal having at least one control command, the control signal being sent from the higher layer device, and a sensing part that senses sensor data with at least one configuration parameter dynamically set by the control command.

In another embodiment, there is provided a sensor system including: a plurality of sensors that senses sensor data with at least one configuration parameter, and a higher layer device that sends a control signal having at least one control command. More than one of the plurality of the sensors senses data with at least one configuration parameter dynamically set by the control command included in the control signal.

In another embodiment, there is provided a method of controlling more than one of a plurality of sensors included in a sensor system, including: a receiving step that receives a control signal having at least one control command, the control signal being sent by a higher layer device of the sensor, and a sensing step that senses sensor data with at least one configuration parameter dynamically set by the control command included in the control signal.

In another embodiment, there is provided an interface used for a sensor system including a plurality of sensors and a higher layer device of the sensor, including at least one of: a frequency command that dynamically sets a frequency of sensor data sensed by more than one of the plurality of the sensors, and an accuracy control command that dynamically sets an accuracy of sensor data sensed by more than one of the plurality of the sensors.

In another embodiment, there is provided a method of controlling a sensor system including a plurality of sensors and a higher layer device of the sensor, including: first collecting step that collects sensor data from the plurality of sensors, first finding step that finds there is something wrong in a sensor's surroundings, changing step that changes a control command included in a control signal in order to set a new configuration parameter of at least one sensor, and that sends the control signal to the at least one sensor, second collecting step that collects sensor data from the at least one sensor with the new configuration parameter been set by the control signal sent by the higher layer device, and second finding step that finds a situation backs to a normal state, and that sends a control signal to the at least one sensor to reset the configuration parameters.

A sensor, a sensor system and a method of controlling a sensor system of the present invention can dynamically tune a configuration parameter of sensor data.

These and other features and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and the claims, the singular form of "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

The above and other objects, advantages and features of the present invention will be more apparent from the following description of certain preferred embodiments taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a schematic view showing a sensor system in the Related Art. Fig. 2 is a schematic view showing a sensor system of an exemplary embodiment of the present invention. Fig. 3 is a schematic block diagram showing a sensor 100 of an exemplary embodiment of the present invention. Fig. 4 is a schematic diagram showing an IDMI control signal 410 of an exemplary embodiment of the present invention. Fig. 5 is a schematic view showing one example of the device using IDMI of an exemplary embodiment of the present invention. Fig. 6 is a schematic view showing another example of the device using IDMI of an exemplary embodiment of the present invention. Fig. 7 is a schematic view showing an application classification of the sensor system of an exemplary embodiment of the present invention. Fig. 8 is a schematic view showing an example of an IDMI control signal format for dynamic configuration of a field level sensor using an IDMI interface of an exemplary embodiment of the present invention. Fig. 9A is a schematic view showing example of the IDMI control signal format of an exemplary embodiment of the present invention. Fig. 9B is a schematic view showing example of the IDMI control signal format of an exemplary embodiment of the present invention. Fig. 9C is a schematic view showing example of the IDMI control signal format of an exemplary embodiment of the present invention. Fig. 10 is a flow chart showing a method for controlling the sensor system of an exemplary embodiment of the present invention. Fig. 11 is a schematic view showing an IoT Reference Architecture with lightweight requirements. Fig. 12 is a schematic view showing a modified gateway with dynamic data management interface of an another exemplary embodiment of the present invention.

For purposes of the description hereinafter, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom", "lateral", "longitudinal", and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to exemplary embodiments disclosed herein are not to be considered as limiting.

As described above, the Related Art in the industrial monitoring application deploys with fixed data rate sensors with pre-set configuration parameters in continuous transmitting mode. Therefore, the inventors of the present invention have proposed a new interface (hereinafter referred to as Intelligent Data Management Interface: IDMI)) which allows to dynamically manage the essential device configuration parameters (i.e., sampling rate and resolution) and also manage the effective channel utilization below the gateway level. This interface enables to effectively manage the way in which the data is collected from field through sensors and transmit only the necessary data to the higher layer, which will maximize the utilization of the available network bandwidth.

Fig. 2 is a schematic view showing a sensor system of an exemplary embodiment of the present invention. As shown in Fig. 2, a sensor system 10 of the exemplary embodiment of the present invention includes a plurality of sensors 100 that sense sensor data with at least one configuration parameter, and an application 300 that sends a control signal having at least one control command as a higher layer device. At least one sensor 100 or all of the sensors 100 sense the sensor data with at least one configuration parameter dynamically set by a control command included in an IDMI (Intelligent Data Management Interface) control signal.

The sensor system 10 further includes a gateway 200, a network infrastructure 210 and a network service provider 220. The sensor system 10 has an IDMI 400 in order to dynamically manage the essential configuration parameters such as a sampling rate and a resolution of the sensors 100. By this, the redundant data traffic can be reduced and the energy utilization of the entire network from the sensors 100 up to the network can be increased.

Firstly, the sensors 100 are explained hereinafter. Fig. 3 is a schematic block diagram showing the sensor 100 of the exemplary embodiment of the present invention. As shown in Fig. 3, the sensor 100 includes a receiving part 101, a channel control part 102, a sensing part 103 and a protection part 104.

The receiving part 101 receives the IDMI control signal having at least one control command. The sensing part 103 senses sensor data with at least one configuration parameter dynamically set by the control command included in the IDMI control signal.

Fig. 4 is a schematic diagram showing an IDMI control signal 410 of the exemplary embodiment of the present invention. As shown in Fig. 4, the IDMI control signal 410 includes a frequency control command 411, an accuracy control command 412, a channel utilization command 413 and a protection command 414. Note that, though it is assumed that the IDMI control signal 410 of the exemplary embodiment of the present invention includes four kinds of commands, the IDMI control signal 410 may not include all of those four commands. For example, the IDMI control signal 410 may only include at least one of those four commands. By the commands included in the IDMI control signal 410, one or more configuration parameters of the sensor 100 of the sensor system 10 are dynamically changed and the sensor 100 can collect the necessary sensor data even when the environment is suddenly changed.

The frequency control command 411 controls a frequency of the sensor data sensed by the sensor 100. The accuracy control command 412 controls an accuracy of the sensor data. The channel utilization command 413 tunes a channel bandwidth in full duplex and half duplex. The protection command 414 shields the sensor system from redundant junk data and/or a malicious packet. The control commands included in the IDMI control signal are set in the higher layer device such as the gateway 200, the network infrastructure 210 and the application 300 so that the configuration parameters of the sensor data are dynamically changed depending on, for example, any one of an environmental change, the rest of the energy, and a type of an application.

Return to the Fig. 3, the sensor 100 further includes the channel control part 102 that tunes a channel bandwidth based on the channel utilization command 413. Further, the sensor 100 includes the protection part 104 that protects the sensor system from received data. That is, the protection part 104 shields the system from at least one of redundant junk data and a malicious packet based on the protection command 414.

The sensing part 103 senses the sensor data with at least one frequency which is dynamically set by the frequency control command 411 and an accuracy which is dynamically set by the accuracy control command 412.

The sensor system 10 can simultaneously coordinate both the data acquisition and data management functions with the IDMI control signal 410. That is, as the sensor system 10 can dynamically tune the sampling rate and resolution of the sensor data, the sensor system 10 can effectively collect and manage the sensor data in the field level. Those configuration parameters are changed based on the user inputs as well as the nature of the application in runtime. That is, the sensor system 10 can transmit only the necessary and accurate data to a controller so as to make a quick decision.

Furthermore, the available channel bandwidth can effectively utilize by dynamically changing the channel mode as Full duplex and half duplex. Therefore, the sensor system 10 can increase energy utilization of the entire network (i.e., from sensor up to the network level), increase the life time of the sensor node, and also maximize the channel utilization when there is a need for optimizing the channel bandwidth utilization.

Fig. 5 and Fig. 6 are schematic views showing examples of the device using IDMI (hereinafter referred to as an IDMI device). The IDMI device is a higher layer device of the sensors 100 and controls the sensor configuration parameters by using the IDMI control signal 410. In the exemplary embodiment of the present invention, the gateway 200 and the application 300 may be used as the IDMI device having the IDMI. When the IDMI is realized in the Gateway 200 it provides the benefits of optimum bandwidth utilizations.

As shown in Fig. 5, one example of the IDMI devices such as the application 300 includes an adaptive data sampler 301, a run time ADC (Analog to Digital Converter) tuner 302, a channel configuration manager 303 and a protection system for higher layer 304.

The adaptive data sampler 301 is used to dynamically change the frequency of the sensor data. The accuracy of the sensor data can be dynamically varied by the run time ADC tuner 302. The channel configuration manager 303 is used for maximizing the channel utilization such as simplex for monitoring and duplex for controlling operations. The protection system for higher layer 304 is defined to shield the sensor system from redundant junk data and malicious packet.

As shown in Fig. 6, another IDMI device such as a personal computer which sends the IDMI control signal 410 to at least one of the plurality of the sensor 100. The personal computer 310 includes an input part 311, a command setting part 312, an environment change monitor 313 and a transmit-receive unit 314. The input part 311 is input data to change the commands included in the IDMI control signal 410 from a user. The command setting part 312 sets the commands included in the IDMI control signal 410 by using the data input from the user. The environment change monitor 313 monitors change in the environment of the sensors 100 by using the sensor data.

If the sensor data value between two points of successive time drastically changes, the environment change monitor 313 decides the sudden change of the environment is happened and, for example, sends a control signal to the command setting part 312 in order to change the sampling rate or the accuracy of the sensor data. The transmit-receive unit 314 sends the IDMI control signal 410 to the sensors 100 through the network infrastructure 210 and the gateway 200, and receives the sensor data from the sensors 100.

Fig. 7 is a schematic view showing an application classification of the sensor system of an exemplary embodiment of the present invention. In Fig. 7, a horizontal axis shows the number of bits of the sensor data, and a vertical axis shows a sampling frequency of the sensor data in the sensor system. As shown in Fig. 7, a sensor application can be classified into four groups (Monitor A0, Reliable A1, Monitor and control A2, Critical A3) based on the data accuracy requirements and the sampling frequency requirements.

That is, when the sensor system 10 does not need sensor data with very high accuracy and with very high sampling frequency, the sensor system 10 can adapt the sensor data in the Monitor A0 area. On the contrary, when the sensor system 10 needs sensor data with high accuracy and high sampling frequency, the sensor system 10 can adapt the sensor data in the Critical A3 area. Further, when the sensor system 10 needs sensor data with only high sampling frequency or with only high accuracy, the sensor system 10 can adapt the sensor data in the Monitor and control A2 area and in the Reliable A1 area respectively.

In an example of monitoring application, a plurality of sensor nodes are deployed to collect data over a period of time to look for trends and seasonal behaviour of particular locations. Typical environment parameters being monitored such as temperature, light intensity and humidity do not change quickly and do not have strict latency requirement. This will fall under the application of Monitor.

In contrast, when these sensor nodes are deployed in a process automation industry to monitor the temperature of a boiler or to monitor the pressure inside a chamber, then the data should be transmitted from the sensor nodes more periodically with less latency. This comes under the application of monitor and control.

When there is an occurrence of abnormal situation, then there is a need for an interface to act according to the situation. The Intelligent Data Management interface (IDMI) used for the sensor system of the exemplary embodiment of the present invention is provided between the field sensors 100 and the gateway 200, or between the field sensors 100 and application 300. In such a case, the user or the system needs sampling data more frequently. Therefore, for example, the user inputs a new IDMI control signal 410 to change a sampling frequency into higher one. Further, once the situation is under control or fault is rectified, then the user can trigger the system to set back the configuration parameters of the sensors 100 to the normal way to obtain data. This will help to avoid adverse effects caused by a sudden increase of temperature.

According to the sensor system 10 of the exemplary embodiment, as the sensors 100 of the sensor system 10 can be controlled by the IDMI control signal 410, the sensors 100 can collect the sensor data with higher frequency. That is, the sensor system 10 can adapt to sudden change in the sensors' environment and the sensors 100 can be used more efficiently, which can increase the life time of the sensors 100.

The details of the individual block of the IDMI device shown in Fig. 5 and the IDMI control signal format to have the communication between the IDMI device and the sensor nodes are explained below. Fig. 8 is a schematic view showing an example of the IDMI control signal format for dynamic configuration of the field level sensor using the IDMI interface of an exemplary embodiment of the present invention. As shown in Fig. 8, the IDMI control signal 410 includes one bit for the channel utilization command 413, two bits for the accuracy control command 412 and five bits for the frequency control command 411.

The IDMI control signal 410 sets the configuration parameter of the sensor 100 and also changes the channel transmission mode. On receiving these commands, the sensor 100 should configure themselves to act for the following scenario. Energy of the sensor 100 is definitely affected when there is a sudden change in its configuration parameters and the way of containing data in critical scenarios. Though this change is a short-term one, the sensor 100 should not deplete its energy resource drastically, which also need to be taken into consideration.

(1) Run time ADC tuner 302:
ADC is a process of converting analog signals to digital signals. The accuracy of the conversion depends on the resolution of the ADC. In the exemplary embodiment of the present invention, the resolution can be adaptive and it is based on the type of application. For example, if an application needs high accurate data, then 32 bit resolution ADC is needed. On the other hand, if an application needs less accurate data, then 8 bit resolution ADC is enough. The number of bits to be transmitted depends on the resolution.

Number of bits transmitted = log (resolution) to base 2
Tuning the resolution causes tuning of bits transmitted, which hence indirectly change the bandwidth utilization. Fig. 9A, Fig. 9B and Fig. 9C are a schematic view showing examples of the IDMI control signal format of the exemplary embodiment of the present invention. Fig. 9A shows the control signal format for this operation, where the digits B0 and B1 are used for selecting four different resolutions. For example, in this format, "00" corresponds to "4 bits", "01" corresponds to "8 bits", "10" corresponds to "16 bits", and "11" corresponds to "32 bits".

(2) Adaptive data sampler 301:
Sampling is a process of converting analog signals to digital signals. Adaptive data sampler 301 changes the frequency of sample. For example, if nature of the process is changing rapidly with respect to time, then the sampling rate at which data to be sampled should be high enough to capture the changes. If nature of the process does not change, then the sampling rate should be low. This adaptation will be done with the adaptive data sampler 301 by sending the IDMI control signal. The signal format is shown in Fig. 9B, where the bits F0 to F4 is used for selecting 32 different sampling frequencies.

(3) Channel configuration manager 303:
The function of the channel configuration manager 303 is to optimally utilize the channel bandwidth based on the nature of the application. As shown in Fig. 9C, it reserves one bit in the control signal format, which can tune the channel either in full duplex (by setting CH bit as '1') or in half duplex (by setting CH bit as '0'). If the sensor nodes are deployed for controlling the application, then CH bit '1' is selected. If the sensor nodes are deployed for monitoring the application, then CH bit '0' is selected. These functions are mainly used in a wired sensor network, which enables the effective utilization of the channel bandwidth.

(4) Protection system for higher layer 304:
The protection system for higher layer 304 decides whether the IDMI device receives the sensor data of one or several specific sensors 100 or not, for example, to shield the system from redundant junk data or a malicious packet.

Note that, the IDMI control signal 410 of the exemplary embodiment of the present invention includes four kinds of commands, but commands included in the IDMI control signal 410 are not limited to those four kinds of commands. For example, if the sensor 100 has one or more functions such as a sensing function and a monitoring function, a new command can be included in the IDMI control signal 410 and the function of the sensor 100 can be changed depending on the situation by the new command included in the IDMI control signal 410.

For example, in a normal state, a sensor A senses data of a temperature of the environment, and in an abnormal situation, for example, if the IDMI device finds that there is something wrong with a behavior of a sensor B which is adjacent to the sensor A, then the IDMI device sends the IDMI control signal 410 including the new command to the sensor A to change the sensing function into the monitoring function. Then the IDMI device can get the information about the sensor B from the monitoring result of the sensor A. If the IDMI device finds the sensor B has a real problem, the IDMI device can isolate the sensor B from the sensor network.

Fig. 10 is a flow chart showing a method for controlling the sensor system of an exemplary embodiment of the present invention. As shown in Fig. 10, assume that the application 300 sets a control commands for a normal operation (Step 1), and then collects the sensor data, for example, temperature data of a boiler room from the sensors 100 placed in the boiler room (Step 2). The application 300 compares a current data with the previous data, and if the difference between them becomes larger than a threshold, the application 300 decides there is something wrong in the boiler room (Step 3: Yes). In this case, for example, the application 300 triggers an alarm or displays a warning on a screen of the application 300 to notify a user that something happened in the boiler room. If the user notices this alarm, the user inputs a new control signal having a new command to the application 300 and the application 300 sends the new control signal to change the configuration parameter of the sensor so as to be able to monitor the temperature more frequently and with larger resolution (Step 4).

As the sensors 100 can sense the sensor data with the higher frequency and the larger resolution than the normal state, the application 300 can collect the sensor data with higher accuracy than the normal state (Step 5). Thus the application 300 can get the necessary sensor data so as to be able to monitor the boiler room in such an emergency situation. Note that, the application 300 may automatically generate a new control signal by itself based on the result of the comparison between current data and the previous data.

After that, if the application 300 continues monitoring the sensor data, and finds the sensor data become a normal data or finds the difference between a current data and the previous data becomes equal to or smaller than the threshold, the application 300 decides the situation is back to a normal state (Step 6: Yes). In this case, the application 300 displays the signal in the screen to notify the user of it. When the user knows the situation becomes stable or the boiler temperature returns to a normal value by the signal, the user inputs a new control signal to change a frequency and a resolution into an initial value (Step 1). Note that, as described above, the application 300 may automatically generate a new control signal by itself based on the result of the comparison of the sensor data. As the sensors 100 sense the sensor data with a normal frequency and resolution, the application 300 can collect the necessary sensor data of the sensors 100 to monitor the boiler room without receiving redundant sensor data.

Note that when the difference between the current data and the previous data is equal to or less than the threshold when the application 300 collects the sensor data in the Step 2 and compares the current data with the previous data, the application 300 returns to the process in the Step 2 (Step 3: No). Further, when the difference between the current data and the previous data is greater than the threshold after the application 300 collects the sensor data in the Step 5, the application 300 returns to the process in the Step 4 (Step 6: No).

According to the exemplary embodiment of the present invention, the sensors of the sensor system can be effectively managed so that the sensor data is collected from field and only the necessary data is transmitted to the higher layer, which will maximize the utilization of the available network bandwidth. That is, by applying the new interface, IDMI, the sensor system can reduce the redundant data traffic and increase energy utilization of the entire network (i.e., from sensor up to the network level). Further, the sensor system of the exemplary embodiment of the present invention can increase the life time of the sensor node and maximizes the channel utilization when there is a need for optimizing the channel bandwidth utilization.

Next, another exemplary embodiment of the present invention will be explained. Fig. 11 is a schematic view showing an IoT (Internet of Things) Reference Architecture with lightweight requirements. As shown in Fig. 11, the Lightweight Restful architecture includes Web services such as applications 350, a Lightweight authentication such as a service platform 360 and a secured communication channel such as IoT core network 260. The service platform is connected to a lightweight device management such as a gateway 250, and a Lightweight communication across devices such as sensors/devices 150 are connected to the gateway 250 through a Lightweight authentication and secured communication such as I1. The IoT core network 260 is connected to the service platform 360 through I2, and the service platform 360 is connected to the applications 350 through I3.

This exemplary embodiment aims to define the detailed I1 interface functionalities of Light weight IoT Reference Architecture. This exemplary embodiment also provides a method to efficiently handle the IoT device management and IoT Gateway Management by introducing some intelligence at the Gateway level.

The exemplary embodiment focuses on defining the I1b capabilities and functionalities. As the existing Light weight IoT baseline architecture specifies the I1b should have the following capabilities, such as Device specific management functions such as sensor sampling configuration, security settings, device registration, device health check, firmware upgrade etc will be done through this IDMI interface. The exemplary embodiment of the present invention provides the dynamic interface functionalities which can be a part of I1b be capabilities.

As described in Fig. 7, IoT applications can be classified into four groups (Monitor, Reliable, Monitor and control, Critical) based on the data accuracy requirements and the sampling frequency requirements. In an example of a monitoring application, the sensor nodes are deployed in the field to collect data over a period of time to look for trends and seasonal behaviour of particular locations. Typical environment parameters being monitored, such as temperature, light intensity, and humidity which does not change quickly and these do not have strict latency requirement. In this case, the sensor nodes should use configuration parameters in Monitor A0 area.

In contrary when these sensor nodes are deployed in a process automation industry, to monitor the temperature of a boiler or to monitor for a pressure inside a chamber, then the data from the sensor nodes should be more periodic with less latency to transmission. In this case, the sensor nodes should use configuration parameters in the monitor and control kind A2 area. When there is an occurrence of abnormal situation, then there is the need for an interface to act according to the situation.

Most of the method of Related Art manages the data at the gateway level. As described above, still there is heavy data traffic below the gateway level where there is lack of available bandwidth in case of wireless sensor network. Therefore there is need of dynamic data management below the gateway so as to maximize the bandwidth utilization as well as the energy efficiency (i.e., increasing the life time of the sensor) of the sensor nodes.

According to the exemplary embodiment, the new dynamic data management interface (IDMI) in between the field sensor and the gateway allows dynamically managing the essential device configuration parameters (i.e., sampling rate and resolution) and also managing the effective channel utilization below the gateway level. These interface functionalities will be added to the I1b capabilities discussed in the IoT baseline architecture documents.

Fig. 12 is a schematic view showing a modified gateway with dynamic data management interface of the exemplary embodiment of the present invention. As shown in Fig. 12, the configuration parameters in the sensor nodes 150 will be dynamically handled and changed by the new interface IDMI having the additional functionality of a runtime ADC tuner 261, a channel configuration manager 262, an adaptive date sampler 263, and a protection system for higher layer 264. The configuration parameters of the sensor nodes 150 of the exemplary embodiment will be completely controlled by the control signal generated by the gateway 250 as well as from the application. The control Signal will be generated in three ways.
1) Trigger from the Application
2) Trigger by the user
3) Trigger generated by the IDMI functionality

A control signal handler 251 in the gateway 250 and a control signal handler 151 in the sensor nodes 150 handle a control signal which includes control commands to set the configuration parameters of the sensor nodes 150.

The benefits of the new functional capabilities in the I1b interface of the exemplary embodiment are as follows.
1) To reduce a redundant data traffic and to increase an energy utilization of the entire network (i.e., from sensor up to the network level)
2) To increase a life time of the sensor node
3) To maximize the channel utilization where there is a need for optimizing the channel bandwidth utilization.

Further, the scope of the claims is not limited by the exemplary embodiments described above.

Furthermore, it is noted that, Applicants' intent is to encompass equivalents of all claim elements, even if amended later during prosecution.

For example, in the above exemplary embodiment, an arbitrary processing can be achieved by executing a program by CPU (Central Processing Unit). The program can be stored and provided to a computer using any type of non-transitory computer readable media. Non-transitory computer readable media include any type of tangible storage media. Examples of non-transitory computer readable media include magnetic storage media (such as floppy disks, magnetic tapes, hard disk drives, etc.), optical magnetic storage media (e.g. magneto-optical disks), CD-ROM (compact disc read only memory), CD-R (compact disc recordable), CD-R/W (compact disc rewritable), and semiconductor memories (such as mask ROM, PROM (programmable ROM), EPROM (erasable PROM), flash ROM, RAM (random access memory), etc.). The program may be provided to a computer using any type of transitory computer readable media. Examples of transitory computer readable media include electric signals, optical signals, and electromagnetic waves. Transitory computer readable media can provide the program to a computer via a wired communication line (e.g. electric wires, and optical fibers) or a wireless communication line.

Further, the whole or part of the exemplary embodiments disclosed above can be described as, but not limited to, the following supplementary notes.
(Supplementary note 1)
A sensor which is used for a sensor system including a plurality of sensors and a higher layer device of the sensor, comprising:
a receiving part that receives a control signal having at least one control command, the control signal being sent from the higher layer device, and
a sensing part that senses sensor data with at least one configuration parameter dynamically set by the control command.
(Supplementary note 2)
The sensor according to Supplementary note 1, wherein the control signal incudes at least one of a frequency control command and an accuracy control command, and the sensing part sense the sensor data with at least one of a frequency being dynamically set by the frequency control command and an accuracy being dynamically set by the accuracy control command.
(Supplementary note 3)
The sensor according to Supplementary note 2, further comprising:
a channel control part that optimizes an utilization of a channel bandwidth, wherein
the control signal further includes a channel utilization command, and the channel control part tunes a channel bandwidth based on the channel utilization command.
(Supplementary note 4)
The sensor according to Supplementary note 3, wherein the channel control part tunes a channel bandwidth in any one of full duplex and half duplex based on the channel utilization command.
(Supplementary note 5)
The sensor according to any one of Supplementary notes 1-4, further comprising:
a protection part that protects a system of the sensor from received data, wherein
the control signal includes a protection command and the protection part shields the system from at least one of redundant junk data and a malicious packet based on the protection command.
(Supplementary note 6)
The sensor according to any one of Supplementary notes 1-5, wherein the control command included in the control signal is set in the higher layer device so that the configuration parameters of the sensor data are dynamically changed depending on at least any one of an environmental change, a rest of an energy resource, and a type of an application.
(Supplementary note 7)
A sensor system comprising:
a plurality of sensors that senses sensor data with at least one configuration parameter, and
a higher layer device that sends a control signal having at least one control command,
wherein at least one sensor senses data with at least one configuration parameter dynamically set by the control command included in the control signal.
(Supplementary note 8)
The sensor system according to Supplementary note 7, wherein the control signal includes at least one of a frequency control command and an accuracy control command, and the at least one of the plurality of the sensors senses data with at least one of a frequency being dynamically set by the frequency control command and an accuracy being dynamically set by the accuracy control command.
(Supplementary note 9)
The sensor system according to Supplementary note 8, wherein the control signal further includes a channel utilization command and the at least one of the plurality of the sensors optimizes a channel bandwidth based on the channel utilization command.
(Supplementary note 10)
The sensor system according to Supplementary note 9, wherein more than one of the plurality of the sensors tunes a channel bandwidth in any one of full duplex and half duplex based on the channel utilization command.
(Supplementary note 11)
The sensor system according to any one of Supplementary notes 7-10, wherein
the control signal includes a protection command and the at least one of the plurality of the sensors shields a system of the sensor from at least one of redundant junk data and a malicious packet based on the protection command.
(Supplementary note 12)
The sensor system according to any one of Supplementary notes 7-11, wherein the control command included in the control signal is set in the higher layer device so that the configuration parameters of the sensor data are dynamically changed depending on at least any one of an environmental change, a rest of an energy resource, and a type of an application.
(Supplementary note 13)
The sensor system according to any one of Supplementary notes 7-12, wherein the higher layer device is a computer being entered data into by a user to set the control command included in the control signal.
(Supplementary note 14)
The sensor system according to any one of Supplementary notes 7-13, wherein the higher layer device is a gateway inputting and outputting the sensor data from the sensor.
(Supplementary note 15)
A method of controlling at least one of a plurality of sensors included in a sensor system, comprising:
a receiving step that receives a control signal having at least one control command, the control signal being sent by a higher layer device of the sensor, and
a sensing step that senses sensor data with at least one configuration parameter dynamically set by the control command included in the control signal.
(Supplementary note 16)
The method of controlling the at least one of the plurality of the sensors of the sensor system according to Supplementary note 15, wherein the control signal includes at least one of a frequency control command and an accuracy control command, and the sensing step sense the sensor data with at least one of a frequency being dynamically set by the frequency control command and an accuracy being dynamically set by the accuracy control command.
(Supplementary note 17)
The method of controlling the at least one of the plurality of the sensors of the sensor system according to Supplementary note 16, further comprising:
a channel control step that optimizes an utilization of a channel bandwidth, wherein
the control signal further includes a channel utilization command, and the channel control step tunes a channel bandwidth based on the channel utilization command included in the control signal.
(Supplementary note 18)
The method of controlling the at least one of the plurality of the sensors of the sensor system according to Supplementary note 17, wherein the channel control step tunes a channel bandwidth in any one of full duplex and half duplex based on the channel utilization command in the control signal.
(Supplementary note 19)
The method of controlling the at least one of the plurality of the sensors of the sensor system according to any one of Supplementary notes 15-18, further comprising:
a protection step that protects a system of the sensor from received data, wherein
the control signal includes a protection command and the protection step shields the system from at least one of redundant junk data and a malicious packet based on the protection command.
(Supplementary note 20)
The method of controlling the at least one of the plurality of the sensors of the sensor system according to any one of Supplementary notes 15-19, wherein the control command included in the control signal is set in the higher layer device so that the configuration parameters of the sensor data are dynamically changed depending on at least any one of an environmental change, a rest of an energy resource, and a type of an application.
(Supplementary note 21)
An interface used for a sensor system including a plurality of sensors and a higher layer device of the sensor, comprising at least one of:
a frequency command that dynamically sets a frequency of sensor data sensed by at least one of the plurality of the sensors, and
an accuracy control command that dynamically sets an accuracy of sensor data sensed by the at least one of the plurality of the sensors.
(Supplementary note 22)
A method of controlling a sensor system including a plurality of sensors and a higher layer device of the sensor, comprising :
first collecting step that collects sensor data from the plurality of sensors;
first finding step that finds there is something wrong in a sensor's surroundings;
changing step that changes a control command included in a control signal in order to set a new configuration parameter of at least one sensor, and that sends the control signal to the at least one sensor;
second collecting step that collects sensor data from the at least one sensor with the new configuration parameter been set by the control signal sent by the higher layer device;
second finding step that finds a situation backs to a normal state, and that sends a control signal to the at least one sensor to reset the configuration parameters.

This application is based upon and claims the benefit of priority from Japanese patent application No.2013-042332, filed on March 4, 2013, the disclosure of which is incorporated herein in its entirely by reference.

10 SENSOR SYSTEM
100 SENSOR
101 RECEIVING PART
102 CHANNEL CONTROL PART
103 SENSING PART
104 PROTECTION PART
150 SENSOR/DEVICES
151 CONTROL SIGNAL HANDLER
200 GATEWAY
210 NETWORK INFRASTRUCTURE
220 NETWORK SERVICE PROVIDER
250 GATEWAY
251 CONTROL SIGNAL HANDLER
260 IOT CORE NETWORK
261 RUNTIME ADC TUNER
262 CHANNEL CONFIGURATION MANAGER
263 ADAPTIVE DATE SAMPLER
264 PROTECTION SYSTEM FOR HIGHER LAYER
300 APPLICATION (IDMI DEVICE)
301 ADAPTIVE DATA SAMPLER
302 RUN TIME ADC TUNER
303 CHANNEL CONFIGURATION MANAGER
304 PROTECTION SYSTEM FOR HIGHER LAYER
310 PERSONAL COMPUTER (IDMI DEVICE)
311 INPUT PART
312 COMMAND SETTING PART
313 ENVIRONMENT CHANGE MONITOR
314 TRANSMIT-RECEIVE UNIT
350 APPLICATIONS
360 SERVICE PLATFORM
400 IDMI
410 IDMI CONTROL SIGNAL
411 FREQUENCY CONTROL COMMAND
412 ACCURACY CONTROL COMMAND
413 CHANNEL UTILIZATION COMMAND
414 PROTECTION COMMAND
1000 SENSOR NETWORK
1100 SENSORS
1200 GATEWAY
1210 NETWORK INFRASTRUCTURE
1220 NETWORK SERVICE PROVIDER
1300 APPLICATION

Claims

A sensor which is used for a sensor system including a plurality of sensors and a higher layer device of the sensor, comprising:
a receiving means for receiving a control signal having at least one control command, the control signal being sent from the higher layer device, and
a sensing means for sensing sensor data with at least one configuration parameter dynamically set by the control command.
The sensor according to claim 1, wherein the control signal includes at least one of a frequency control command and an accuracy control command, and the sensing means sense the sensor data with at least one of a frequency being dynamically set by the frequency control command and an accuracy being dynamically set by the accuracy control command.
The sensor according to claim 2, further comprising:
a channel control means for optimizing an utilization of a channel bandwidth, wherein
the control signal further includes a channel utilization command, and the channel control means tunes a channel bandwidth based on the channel utilization command.
The sensor according to claim 3, wherein the channel control means tunes a channel bandwidth in any one of full duplex and half duplex based on the channel utilization command.
The sensor according to any one of claims 1-4, further comprising:
a protection means for protecting a system of the sensor from received data, wherein
the control signal includes a protection command and the protection means shields the system from at least one of redundant junk data and a malicious packet based on the protection command.
The sensor according to any one of claims 1-5, wherein the control command included in the control signal is set in the higher layer device so that the configuration parameters of the sensor data are dynamically changed depending on at least any one of an environmental change, a rest of an energy resource, and a type of an application.
A sensor system comprising:
a plurality of sensors that senses sensor data with at least one configuration parameter, and
a higher layer device that sends a control signal having at least one control command,
wherein at least one sensor senses data with at least one configuration parameter dynamically set by the control command included in the control signal.
The sensor system according to claim 7, wherein the control signal includes at least one of a frequency control command and an accuracy control command, and the at least one of the plurality of the sensors senses data with at least one of a frequency being dynamically set by the frequency control command and an accuracy being dynamically set by the accuracy control command.
The sensor system according to claim 8, wherein the control signal further includes a channel utilization command and the at least one of the plurality of the sensors optimizes a channel bandwidth based on the channel utilization command.
The sensor system according to claim 9, wherein more than one of the plurality of the sensors tunes a channel bandwidth in any one of full duplex and half duplex based on the channel utilization command.
The sensor system according to any one of claims 7-10, wherein
the control signal includes a protection command and the at least one of the plurality of the sensors shields a system of the sensor from at least one of redundant junk data and a malicious packet based on the protection command.
The sensor system according to any one of claims 7-11, wherein the control command included in the control signal is set in the higher layer device so that the configuration parameters of the sensor data are dynamically changed depending on at least any one of an environmental change, a rest of an energy resource, and a type of an application.
The sensor system according to any one of claims 7-12, wherein the higher layer device is a computer being entered data into by a user to set the control command included in the control signal.
The sensor system according to any one of claims 7-13, wherein the higher layer device is a gateway inputting and outputting the sensor data from the sensor.
A method of controlling at least one of a plurality of sensors included in a sensor system, comprising:
receiving a control signal having at least one control command, the control signal being sent by a higher layer device of the sensor, and
sensing sensor data with at least one configuration parameter dynamically set by the control command included in the control signal.
The method of controlling the at least one of the plurality of the sensors of the sensor system according to claim 15, wherein the control signal includes at least one of a frequency control command and an accuracy control command, and the sensing sensor data with at least one configuration parameter dynamically set by the control command included in the control signal sense the sensor data with at least one of a frequency being dynamically set by the frequency control command and an accuracy being dynamically set by the accuracy control command.
The method of controlling the at least one of the plurality of the sensors of the sensor system according to claim 16, further comprising:
optimizing an utilization of a channel bandwidth, wherein
the control signal further includes a channel utilization command, and the optimizing an utilization of a channel bandwidth tunes a channel bandwidth based on the channel utilization command included in the control signal.
The method of controlling the at least one of the plurality of the sensors of the sensor system according to claim 17, wherein the optimizing an utilization of a channel bandwidth tunes a channel bandwidth in any one of full duplex and half duplex based on the channel utilization command in the control signal.
The method of controlling the at least one of the plurality of the sensors of the sensor system according to any one of claims 15-18, further comprising:
protecting a system of the sensor from received data, wherein
the control signal includes a protection command and the protecting a system of the sensor from received data shields the system from at least one of redundant junk data and a malicious packet based on the protection command.
The method of controlling the at least one of the plurality of the sensors of the sensor system according to any one of claims 15-19, wherein the control command included in the control signal is set in the higher layer device so that the configuration parameters of the sensor data are dynamically changed depending on at least any one of an environmental change, a rest of an energy resource, and a type of an application.
An interface used for a sensor system including a plurality of sensors and a higher layer device of the sensor, comprising at least one of:
a frequency command that dynamically sets a frequency of sensor data sensed by at least one of the plurality of the sensors, and
an accuracy control command that dynamically sets an accuracy of sensor data sensed by the at least one of the plurality of the sensors.
A method of controlling a sensor system including a plurality of sensors and a higher layer device of the sensor, comprising :
collecting sensor data from the plurality of sensors;
finding there is something wrong in a sensor's surroundings;
changing a control command included in a control signal in order to set a new configuration parameter of at least one sensor, and that sends the control signal to the at least one sensor;
collecting sensor data from the at least one sensor with the new configuration parameter been set by the control signal sent by the higher layer device;
finding a situation backs to a normal state, and that sends a control signal to the at least one sensor to reset the configuration parameters.