Based on the context of ubiquitous wireless sensor network (WSN), design of a wireless sensor network and a low power water level monitoring station for urban environment are proposed in this paper. A ubiquitous WSNs based on a high performance and low power consumption Texas Instrument CC1110 module is presented and investigated.
Electronics and Automation ON THE DESIGN OF LOW POWER CONSUMPTION WATER LEVEL MONITORING STATION FOR URBAN ENVIRONMENT BASED ON WIRELESS SENSOR NETWORK Nguyen Tuan Duc1*, Le Quoc Cuong2 Abstract: Based on the context of ubiquitous wireless sensor network (WSN), design of a wireless sensor network and a low power water level monitoring station for urban environment are proposed in this paper A ubiquitous WSNs based on a high performance and low power consumption Texas Instrument CC1110 module is presented and investigated Through this ubiquitous WSNs, water level measured from many monitoring stations are sent to the base station via a GPRS/3G gateway and then are forwarded to a data center In order to ensure a longterm operation with a limited solar power supply in environment, a low power consumption design of a water level monitoring station is also proposed The power consumption of the proposed station is estimated and solar power supply calculation for this station is also investigated With an advantage of low power consumption station and ubiquitous wireless monitoring network, the system can be applied widely in urban environment in developing countries like Vietnam Keywords: Wireless sensor network, Low power consumption network, Energy efficiency, Water level monitoring INTRODUCTION Following the research of United Nations Development Programe (UNDP), Vietnam is a one countries which are heavy influenced by climate change and the rise of sea level For the record, every 1m of sea level rising will impact on 5% land resource, 11% population and 7% agriculture and 10% GDP decreasing [1] There are more and more evidences prove that climate change is increasing the intensity and density of environment catastrophe in Vietnam Climate change also impact on water resource such as water current, flood, and increasing evaporation, it will lead to the influence on social life and food production activities Moreover, the salt intrusion and erosion because of sea level rise which are threats to the economy and social life of the population In many big cities, owing to climate change, the tide situation of river systems as well as flooded situation by heavy rain are more and more serious The reason is that drainage system is overloaded and jammed, it will lead to the economic and society damage Especially, the flooded situation affects directly on citizen and companies activities In order to react with climate change effects and limit the harmful effects of flooded situation in big cities, the demand is to build a system which can monitor the water level on around a city in order to track the river-canal level, tide and flooded situation, then based on that data, suitable reactions will be made [2][3] In recent years, wireless sensor network (WSN) technology has been deployed into environment system as a new way to monitor and improve the relationship between human and environment WSN system can help increase agricultural products and interact with nature There are many researches for WSN in environmental monitoring applications in couple years, by using sensor to observe the gradual change of environment in real-time [4] Climatic sensor is spread on a specific area in order to measure the climatic data and network system can send these data to people for processing [5][6] A combining network is considered as an ubiquitous wireless sensor network that can allow wireless sensor devices to connect to control center at anytime and from anywhere 48 N T Duc, L.Q.Cuong, "On the design of low power consumption ” Research by different wireless technologies Since wireless sensor network can cover a specific area, the combine of GPRS/3G cellular network technology with WSN which can help reduce the total cost for a network system [7] Hence, based on this combination, a water level monitoring system can be deployed all around a city This paper proposes a water level monitoring system for urban environment based on WSN This system will be designed based on characteristics of WSN which follow the goal of low cost and low power consumption For practical deployment as a automatic monitoring system, this system must be low power consumption and can survive without battery recharging during a long period Energy consumption of this system is evaluated in order to prove the possibility of this system and to compare with current systems; then proposes an optimum solution for a water level monitoring station In current market, a high cost up to 60000 USD for a monitoring station and a collecting data system will limit the deployment in a huge number of stations in developing countries A low cost for water level monitoring station by using low cost devices and without maintaining cost would bring an opportunity to apply this system in large-scale areas for developing countries like Vietnam [8] [9] This paper is organized as follows Section shows the design of overall water level monitoring system based on a ubiquitous WSN In Section 3, wireless sensor network hardware is selected and water level monitoring station hardware design is proposed In Section 4, the power consumption estimation of the monitoring station is investigated to prove the energy efficiency In order to show the possibility of this design, experiments and results are presented in Section Finally, a conclusion is given in Section OVERALL SYSTEM DESIGN In order to deploy a monitoring network which can cover all a city, this paper proposes a network system based on the operation procedures: a) A monitoring network cover whole the city and track the water level of river-canal and the flooded level on the street when tide or heavy rain happens in many area in the city b) A monitoring parameter of water level and flooded situations will be sent automatically to data center in real time Based on 3G/GPRS and wireless sensor network This combine network is called ubiquitous wireless sensor network and it has many advantages when compared with only cellular network or wired network c) Data of water level will be stored at data center and people can access easily based on Web interface and Internet connection The overall structure of water level monitoring system is shown in Fig This network is divided into many cluster by combining GPRS/3G and WSN Each cluster has one Data Station and many water level stations After getting data of water level, the station will send these data to Data Station by a wireless node The role of Data Station is that received message from water level station and then processing, storing and transmitting these data to Database Center The advantages of this design is low cost because there is no need to integrate GPRS/3G modem for all stations which have a high cost for cellular network Moreover, this system not depend on mobile service Journal of Military Science and Technology, Special Issue, No.48A, - 2017 49 Electronics and Automation Figure Overall design for water level monitoring system HARDWARE DESIGN A Energy efficiency wireless sensor network Goals of this task is investigating a wireless hardware with low cost, low power consumption and reliable transmission in urban environment, this section focuses on study of a suitable wireless hardware for the Water level monitoring network A comparison of some modern transceivers on market is shown on Table I, then a suitable transceiver will be chosen based on these criteria above Following Table I, CC1110 device has the advantage of integrated MCU, it will lead to saving cost for a wireless module: a) CC1110 has a higher reliable transmission than MRF24J40MD At 1.2 kbps data rate, CC1110 has a receive sensitivity -110 dBm with Packet error rate is 10−2 while ZigBee device MRF24J40MD has Bit error rate is 10−3 at the same receive sensitivity Beside, MRF24J40MD integrates with a power amplifier, so that energy consumption will be much higher than CC1110 at transmission mode b) In the case of transmission distance, CC1110 has longer transmission than the other (the range up to 1.2 Km in free space and line of sight), it can also transmit signal 50 N T Duc, L.Q.Cuong, "On the design of low power consumption ” Research as far as 550m in urban environment Besides, MRF24J40MD is a latest product of ZigBee which has 350 m in urban environment and equipped by a power amplifier c) However, transmission range of MRF24J40 is not good as CC1110, since it works on 2.4 GHz frequency band This is a frequency band with highly noise and there are many working applications on this frequency band Signal on 2.4 GHz band is lost too much when it is transmitted in many obstacles environment, the reflectivity and refraction are not good as 800-900 MHz Especially, 2.4 GHz is absorbed too much by water In general, for water level monitoring application, 2.4 GHz frequency band is not suitable Table I Hardware comparison of WSN nodes Beside some practical testing range for CC1110, it is easy to see that CC1110 wireless device is an appropriate wireless module for a water level monitoring station [10] Fig illustrates for CC1110 mini development kit Journal of Military Science and Technology, Special Issue, No.48A, - 2017 51 Electronics and Automation Figure CC1110 mini development kit B Water level monitoring station Fig shows the structure of hardware design water level station There are four blocks: Sensors, Data logger, Gateway and Power supply Since the node platforms is design with solar cell, a large capacity battery and reliable DC-DC converting circuit have been well considered for the power supply module Figure Block diagram of Data station a) Water level sensor: This paper proposes a method which uses pressure sensor for water level measurement The principle of this method is use one sensor to measure the pressure of water Level of the liquid will be determined based on the pressure at the sensor position For automatic monitoring station design, water level sensor should be high quality for a long term operation in environment The pressure sensor like Heron pressure sensor is a suitable solution for this design which is illustrated in Fig This sensor is adaptable for this water level monitoring application, with a good noise avoidance function and can sustainable operate in lengths down to 600m under the water This sensor need 12V power supply and give an industry standard output 4-20 mA signal 52 N T Duc, L.Q.Cuong, "On the design of low power consumption ” Research Figure Pressure sensor for water level measurement In data processing part of monitoring station, an Analog to Digital Converter (ADC) is used to convert the electricity current 4-20 mA from sensor This signal is converted to voltage signal and then processed by the MCU This task is done by the Data logger and create the output from to 5V for water level calibration b) Data logger: Data logger is an electronic programmable instrument based on a power-full micro-controller AT-mega2560 that records environmental data from sensors In this design, our data logger can hold up data for several months by using a high capacity SD card module and is equipped with a 10-bit-resolution ADC and a wide variety of analog and digital input/output (I/O) ports to interface with numerous environment sensors such as water level and many different types of sensor To enable communication with other external devices, Data logger is equipped a range of peripheral ports such as RS-232, USB and Ethernet on the gateway module c) Gateway: Connecting to Data logger, the gateway block provide a standard set of on-board peripherals to interface with external communication modules With four UART ports on chip, AT-mega2560 is well suited to communicate with various communication modules For example, two UART work as RS-232 serial port to interface with GPRS modem and CC1110 wireless module, a FT232 port to interface with computer, and another COM port to interface with the Ethernet module Wireless sensor network CC1110 module operating in 868 MHz are always integrated in the gateway of monitoring station (shown as sub Ghz wireless on the Fig 3) d) Power Supply: Power management is essential for long-term operation To survive extreme weather conditions in long-term operation, we propose a solar supply power system with a battery that help the monitoring station work at least days without recharging Power supply design is investigated in next section POWER CONSUMPTION ESTIMATION AND POWER SUPPLY DESIGN In this section the power consumption estimation of the designed monitoring is calculated Then, the capacity of a back-up battery and solar panel power are also proposed based on the power consumption of station and the working days requirement In order to reduce the power consumption, the water level sensor, the data logger, MCUs, GPRS modem and CC1110 are kept Active or Idle depending on each working states The radio transceiver is a big energy consumer: keeping it on all the time may lead to a negative energy balance Consequently, duty cycling provides an effective way to achieve energy efficiency which is calculated by the ratio of Active time and Total time In this Journal of Military Science and Technology, Special Issue, No.48A, - 2017 53 Electronics and Automation setup, the wireless modem wakes up for 30 seconds every 15 minutes for data collection which is equivalent to a duty cycle of about 3.3% To calculate the duty circle of sensor and CC1110 transceiver Let assumes the sensor get data from environment every minutes and take 10 seconds for each time Beside, CC1110 transceiver transmits data every 15 minutes per time in two ways communication, transmit time is set minutes Duty circle of sensor take 3.3% and transceiver take 6.7% In this design, the duty cycle of active and Idle states of each component is presented on Table II Table II Data Station Power Consumption Estimation Table II illustrates also the power consumption (including average current and working voltage) of each component inside the monitoring station The total average power draw of this monitoring can be calculated as 207mW which is very efficient Using the power calculation in Table II, if a battery capacity of 4000mAh (12V voltage) is used, the theoretical time for the next charging is given by 4000(mAh)*12(V)/207(mW) = 231 hours (or 9.7 days) In practice, a lead-acid battery cannot be 100% discharged repeatedly Therefore, it is necessary to derate the battery by some amount, generally 25% In this case, 25% of 4000mAh is about 3000mAh So the practical time between recharging times is now given by 3000(mAh)*12(V)/207(mW) = 173 hours (or 7.2 days) Hence, the battery may support the system for more than days without recharging, that satisfy the design goal Cause efficient working hours per one day of a solar panel is hours average, the capacity of a solar panel should be at least times the average power consumption of the load in general By the above calculation in the Table II, the average power consumption is 207(mW), then a minimum power load of solar panel would be about 207mw*4= 828mW This is a reason why a 12V and 1W solar panel is selected for power supply design EXPERIMENT AND HARDWARE RESULT A CC1110 distance test Table III shows a practical range testing of CC1110 module in real case of a city environments Results of transmission distance test in Table II prove that CC1110 transmission range is very appropriate for the proposed water level monitoring station network where node-to-coordinator distance is typically less than 500m when sending 1000 packets with 1.2 kbps data rate on 868 MHz working frequency 54 N T Duc, L.Q.Cuong, "On the design of low power consumption ” Research Table III CC1110 testing range result table CC1110 allows a small size wireless module to be integrated in data-logger circuit of water level monitoring station Moreover, Texas Instrument network protocols (SimpliciTi ore wireless M-Bus) supports for CC1110 transceiver, so that we can deploy an efficient star routing network for one Cluster in Fig The structure of SimpliciTI protocol is presented in Fig To extend the network coverage, this protocol also supports range extenders function Figure SimpliciTI protocol structure B An experiment monitoring station Fig shows some components of a real experiment monitoring station including: Data logger (and LCD screen), sensor ADC board, GPRS module and battery of power supply module This station has been tested for a long time in our Lab at International University of HCMC Journal of Military Science and Technology, Special Issue, No.48A, - 2017 55 Electronics and Automation Figure Experimental design of water level monitoring station CONCLUSION In this paper, the energy efficient system for water level monitoring in urban environment is proposed This system bases on ubiquitous WSNs and low power consumption water level monitoring station The power efficiency of wireless sensor network based on Texas instrument CC1110 hardware have been investigated and the power consumption of the monitoring station have been estimated to prove the energy efficiency of this system The low power consumption of the proposed monitoring station ensures that it can work for days with a 3000mAh 12V battery In the end, data of wireless transmission distance test of CC1110 wireless module and hardware implementation of the monitoring station have been shown ACKNOWLEDGEMENT: This research was supported by the Vietnam National Foundation for Science and Technology Development (No 102.01-2011.22) REFERENCES [1] UNDP, “United nations development programme.” [Online] Available: http://www.undp.org [2] J Beckheinrich, A Hirrle, S Schon, G Beyerle, M Semmling, and J Wickert, “Water level monitoring of the mekong delta using gnss reflectometry technique,” in 2014 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), pp 3798–3801, 2014 [3] J B Rosolem, D C Dini, R Strobel Penze, C Floridia, A A Leonardi, M Dias Loichate, and A Stano Durelli, “Fiber optic bending sensor for water level monitoring: Development and field test: A review,” Sensors Journal, IEEE, vol 13, no 11, pp 4113–4120, 2013 [4] B Chang and X Zhang, “Aquaculture monitoring system based on fuzzy-pid algorithm and intelligent sensor networks,” in 2013 IEEE Cross Strait QuadRegional Radio Science and Wireless Technology Conference (CSQRWC), 2013, pp 385–388 56 N T Duc, L.Q.Cuong, "On the design of low power consumption ” Research [5] Y Dasgupta and P Darshan, “Application of wireless sensor network in remote monitoring: Water-level sensing and temperature sensing, and their application in agriculture,” 2014 First International Conference on in Automation, Control, Energy and Systems (ACES), 2014, pp 1–3 [6] S Verma et al., “Wireless sensor network application for water quality monitoring in India,” in 2012 National Conference on Computing and Communication Systems (NCCCS), 2012, pp 1–5 [7] Q Wu, Y Liang, Y Sun, C Zhang, and P Liu, “Application of gprs technology in water quality monitoring system,” in IEEE World Automation Congress (WAC), 2010, pp 7–11 [8] A Al-Ali, I Zualkernan, and F Aloul, “A mobile gprs-sensors array for air pollution monitoring,” IEEE Sensors Journal, vol 10, no 10, pp 1666–1671, 2010 [9] A Ghobakhlou, S Zandi, and P Sallis, “Development of environmental monitoring system with wireless sensor networks,” International Congress on Modelling and Simulation (MODSIM2011), pp 1125-1131, 2011 [10].Texas Instruments, CC1110 datasheet, Texas Instruments [Online] Available: www.ti.com/general/docs/lit TÓM TẮT THIẾT KẾ TRẠM GIÁM SÁT MỰC NƯỚC TIÊU THỤ ĐIỆN NĂNG THẤP CHO MÔI TRƯỜNG ĐÔ THỊ DỰA TRÊN CÔNG NGHỆ MẠNG CẢM BIẾN KHƠNG DÂY Dựa cơng nghệ mạng cảm biến không dây thông suốt, thiết kế mạng cảm biến không dây thông suốt (WSN) trạm giám sát mực nước điện thấp cho môi trường đô thị đề xuất báo Mạng WSN dựa mô-đun không dây hiệu cao công suất thấp Texas Instrument CC1110 nghiên cứu Thông qua mạng WSN này, mực nước đo đạc từ trạm giám sát truyền trạm gốc chuyển tiếp trung tâm liệu thông qua thiết bị cửa ngõ GPRS/3G Để đảm bảo hoạt động liên tục với nguồn cấp lượng mặt trời có hạn, thiết kế tiết kiệm lượng trạm giám sát đề xuất Mức tiêu thụ lượng trạm ước lượng tính tốn nguồn cấp lượng mặt trời thực Với ưu tiêu thụ lượng thấp mạng cảm biến khơng dây thơng suốt, hệ thống ứng dụng rộng rãi môi trường đô thị quốc gia phát triển Việt Nam Từ khóa: Mạng cảm biến không dây, Giám sát môi trường, Trạm giám sát mực nước, Mạng tiêu thụ lượng thấp Received date, 13th June, 2016 Revised manuscript, 15th March 2017 Published on 26th April 2017 Author affiliations: International University, Vietnam National University Department of Information and Communications of HCM city, Vietnam *Corresponding author: ntduc@hcmiu.edu.vn Journal of Military Science and Technology, Special Issue, No.48A, - 2017 57 ... and low power consumption water level monitoring station The power efficiency of wireless sensor network based on Texas instrument CC1110 hardware have been investigated and the power consumption. .. 3, wireless sensor network hardware is selected and water level monitoring station hardware design is proposed In Section 4, the power consumption estimation of the monitoring station is investigated... panel power are also proposed based on the power consumption of station and the working days requirement In order to reduce the power consumption, the water level sensor, the data logger, MCUs, GPRS