GreenDays@Sophia 2017
Evaluation of Energy-efficient Data Collection in Mobile Crowdsensing Systems with CrowdSenSim Simulator Andrea Capponi
University of Luxembourg
Claudio Fiandrino
Imdea Networks Institute
Giuseppe Cacciatore Dzmitry Kliazovich Pascal Bouvry
University of Trento ExaMotive University of Luxembourg June 27, 2017
Smart Cities: Introduction I
50% of worldwide population lives in cities
I
Cities account for I
80% of worldwide gas consumption
I
75% of global energy consumption
I
60% of residential water use
N. B. Grimm, S. H. Faeth, N. E. Golubiewski, C. L. Redman, J. Wu, X. Bai, and J. M. Briggs, “Global change and the ecology of cities,” in Science, vol. 319, no. 5864, 2008, pp. 756–760.
Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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IoT for Smart Cities Improve citizens’ quality of life with innovative and sustainable solutions for public services: I
Smart parking
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Waste management
I
Public lighting
I
IoT candidate building block for Smart Cities solutions
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Sensing as a Service (S2 aaS) for IoT Sensors
Consumers
Cloud Providers
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Mobile Crowdsensing I
Appealing paradigm for sensing and collecting data I
Monitoring phenomena in smart cities
I
Sensing as a Service (S2 aaS) business model
I
Sensors commonly available in mobile and IoT devices
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Mobile Crowdsensing I
Appealing paradigm for sensing and collecting data I
Monitoring phenomena in smart cities
I
Sensing as a Service (S2 aaS) business model
I
Sensors commonly available in mobile and IoT devices
Figure: Diffusion of mobile devices Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Mobile Crowdsensing I
Appealing paradigm for sensing and collecting data I
Monitoring phenomena in smart cities
I
Sensing as a Service (S2 aaS) business model
I
Sensors commonly available in mobile and IoT devices
Figure: Diffusion of mobile devices Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Sensing Paradigms
I
Two sensing paradigms:
Participatory
Opportunistic
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Active user engagement
I
Minimal user involvement
I
Sensing and reporting user-driven
I
Sensing and reporting application- or device-driven
I
Centralized, direct task assignment
I
Distributed, no direct task assignment
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Outline
Framework for Data Collection in Opportunistic Sensing Systems
User Recruitment
Smart Lighting
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Outline
Framework for Data Collection in Opportunistic Sensing Systems
User Recruitment
Smart Lighting
Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Mobile Crowdsensing Scenario Environmental Context Cs
S2 aaS Cloud Collector
Crowd iFi W
ta Da
Data Collection Utility dsa
E LT
Threshold δ
Accelerometer
IoT Devices Gyroscope
Microphone
Dual Camera
Temperature
Smartphone Sensing Potential sps
Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Mobile Crowdsensing Scenario Environmental Context Cs
S2 aaS Cloud Collector
Crowd iFi W
ta Da
Data Collection Utility dsa
E LT
Threshold δ
Accelerometer
IoT Devices Gyroscope
Microphone
Dual Camera
Temperature
Smartphone Sensing Potential sps
Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Proposed Opportunistic Framework
Sensing Decision Policy Cs · [γ · sps + (1 − γ) · dsa ] > δ
Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Proposed Opportunistic Framework
Data Collection Utility
Threshold
Sensing Decision Policy Cs · [γ · sps + (1 − γ) · dsa ] > δ
Environmental Context
Smartphone Sensing Potential
Balancing Coefficient
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Proposed Opportunistic Framework
I
Data Collection Utility dsa I I
I
Defines utility for the cloud collector Based on number of samples already received
Smartphone Sensing Potential, sps I
Function of locally spent energy Es for sensing and reporting Es = Esc + Esr
I
Environmental Context Cs I
I
Binary value which depends on the context awareness
Threshold δ I
Depends on the level of battery of the devices (B) and the amount of reported data that devices have already contributed (D)
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CrowdSenSim I
Custom simulator for crowdsensing activities I I
Access and download: http://crowdsensim.gforge.uni.lu Contact:
[email protected]
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CrowdSenSim: Features and Architecture I
Large scale (time-space)
I
Realistic urban environments City Layout
List of Events
CrowdSensing Inputs
User Mobility
S IMULATOR
Results
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Evaluation Settings
I
3 sensors: accelerometer, temperature, pressure
I
Users: 20 000
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Walking speed: U [1 − 1.5] m/s
I
Walking period: U [10 − 20] min
I
Simulation period: 8 AM - 2 PM
I
Digipoint to provide street-level maps
I
City centers of Luxembourg, Madrid and Trento
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Performance Evaluation
Traces
0-50 50-100 100-150 150-200 200-250 250-300 300-350 350-400 400-450 450-500 500-550 550-600 600-650 650-700 700-750 750-800 800-850 850-900
Uniform
Current drain (µAh)
(a) Sensing Cost
3 500 3 000 2 500 2 000 1 500 1 000 500 0
Uniform
Traces
0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50 50-55 55-60 60-65 65-70 70-75 75-80 80-85
3 500 3 000 2 500 2 000 1 500 1 000 500 0
Num. of Participants
Energy spent for sensing and communications
Num. of Participants
I
Energy (J)
(b) Communication Cost
I
Sensing and communication same distribution but different scales
I
Real-world traces are the results of a study on pedestrian mobility and are public available on Crawdad (ostermalm_dense_run2) 1 1 http://crawdad.org/kth/walkers/20140505
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Performance Evaluation
I
Normalized distribution of amount of collected data for the different cities over the time period 8:00 AM - 2:00 PM
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
(a) Luxembourg
1
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
(b) Trento
1
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
1
(c) Madrid
Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Outline
Framework for Data Collection in Opportunistic Sensing Systems
User Recruitment
Smart Lighting
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The DSE Recruitment Policy The recruitment problem
I
I
Select users able to fulfill the task with high accuracy
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Minimize costs of the organizer/users
I
Recruit a minimum number of users N
Three factors define user eligibility I I I
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Distance from sensing task Sociability Remaining battery charge
Acceptance: sociability and energy
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Cloud
High Computing Capacity High Latency Global View
O RGANIZER /C OLLECTOR: Global Analytics, Task Definition, Initiator User Recruitment Process
Fog
Proposed Fog Platform
C LOUDLET: Local Analytics, ID assignment, Computation of Recruitment Factor
Low Computing Capacity Low Latency Local View
I
Fog computes social factor
I
Extension: anonymity, privacy
M OBILE I O T D EVICES: Sensing Task
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Evaluation Settings
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10 000 participants
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6 cloudlets
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Walking speed: U [1 − 1.5] m/s
I
Walking period: U [10 − 30] min
I
Simulation period: 8 AM - 2 PM
I
Set of 25 tasks (40 minutes each)
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Distribution of Contacted vs Recruited Users I
DSE policy
Contacted
Recruited
Number of Users
150 125 100 75 50 25 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Task ID Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Distribution of Contacted vs Recruited Users I
Distance-only policy
Contacted
Recruited
Number of Users
150 125 100 75 50 25 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Task ID Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Outline
Framework for Data Collection in Opportunistic Sensing Systems
User Recruitment
Smart Lighting
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Current Street Lighting Implementations (I) Not environmental sustainable: I
19% of worldwide use of electrical energy
I
6% of total emissions of greenhouse gases
I
40% of the cities’ energy budget
European Energy Innovation Publisher, “LED Lighting Technologies”, in 2nd Annual LED Professional Symposium & Exhibition.
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Current Street Lighting Implementations (II)
Not energy efficient because of I
technology
I
control system
T YPE OF L AMPS
N OM . WATTAGE (W)
L AMP E FFICACY ( LM /W)
E NERGY ( K W H /1000 H )
AVERAGE LIFE ( H )
HPS-97241 HPS-93010296 MH-NaSc LED-GRN60 LED-GRN100
150.0 250.0 100.0 46.8 73.3
110.0 129.0 90.0 131.0 138.0
172.7 283.4 165.0 51.8 82.7
24 000 24 000 10 000 100 000 100 000
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New Heuristics for Street Lighting (I) The new proposed heuristics rely on occupancy 2 and each lamppost operates independently I
IoT-augmented lamps
I
Strategies: I
Delay-based (D EL)
I
Encounter-based (E NC)
I
Dimming (D IM)
R
2 F. Leccese, "Remote-Control System of High Efficiency and Intelligent Street Lighting Using a ZigBee Network of Devices and Sensors," in IEEE Transactions on Power Delivery, vol. 28, no. 1, pp. 21-28, Jan. 2013. Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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New Heuristics for Street Lighting (II) M ETHOD
D ESCRIPTION
Current (C UR)
Lampposts continuously active emitting maximum light intensity
LO
Delay-based (D EL)
Lampposts switched on when users pass nearby. If nobody is present within R, lampposts remain active for time window W and then are switched off.
HI
Encounter-based (E NC)
Lampposts switched upon the first encounter with at least one user and remain active the whole night.
ME
Dimming (D IM)
Lampposts operate at 60% light intensity in absence of users within R. Lampposts light up/dim the intensity in proportion to the number of nearby users.
HI
Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
E FFICACY
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Evaluation Settings
Luxembourg City center
I
Users: 20 000
I
Walking speed: U [1 − 1.5] m/s
I
Walking period: U [10 − 20] min
I
Simulation period: 9 PM - 7 AM
I
537 Lampposts
I
R: {10, 30, 50} m
0.3
PDF
I
0.2 0.1 0
9-10 10-11 11-12 12-1 1-2 PM
2-3
3-4
4-5
5-6
6-7
AM
Time Interval (hour)
Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Energy consumption (kW/day)
Energy Comparison of Heuristics C UR
E NC
D EL
D IM
1 000 800 600 400 200 0
10
30
50
Radius (m)
I
D IM significantly outperforms other heuristics
I
E NC already improves current systems
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Heatmap of Energy Consumption
I
Comparison ENC vs DEL3 170
170
160
160
150
150
140
140
130
130
120
120
110
110
100
100
90
90
80
80
70
70
60
60
50
50
3 https://developers.google.com/maps/documentation/javascript/examples/layerheatmap Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Conclusion CrowdSenSim I
Performance evaluation in large realistic urban environments I
MCS systems for S2 aaS applications in smart cities I I I
I
Framework for cost effective data collection Energy efficient user recruitment Energy efficient public street lighting
Custom simulator for crowdsensing activities I
Access and download: http://crowdsensim.gforge.uni.lu
I
Contact:
[email protected]
Future work I
HyDACQ: Hybryd Data ACQuisition paradigm
I
Smartphone cooperation for sensing and data relaying using D2D More advanced solutions: predicted users’ mobility, cluster control
I
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Publications 1. A. Capponi, C. Fiandrino, C. Franck, U. Sorger, D. Kliazovich, and P. Bouvry, "Assessing Performance of Internet of Things-Based Mobile Crowdsensing Systems for Sensing as a Service Applications in Smart Cities", in IEEE CLOUDCOM, Dec 2016, Luxembourg. 2. C. Fiandrino, A. Capponi, G. Cacciatore, D. Kliazovich, U. Sorger, P. Bouvry, B. Kantarci, F. Granelli and S. Giordano, "CrowdSenSim: a Simulation Platform for Mobile Crowdsensing in Realistic Urban Environments", in IEEE ACCESS, Feb 2017. 3. A. Capponi, C. Fiandrino, D. Kliazovich, P. Bouvry and S. Giordano, "Energy Efficient Data Collection in Opportunistic Mobile Crowdsensing Architectures for Smart Cities", in IEEE INFOCOM WKSHPS on Smart Cities and Urban Computing (SmartCity), May 2017, Atlanta, GA, USA. 4. A. Capponi, C. Fiandrino, D. Kliazovich, P. Bouvry and S. Giordano, "A Cost-Effective Distributed Framework for Data Collection in Cloud-based Mobile Crowd Sensing Architectures", in IEEE Transactions on Sustainable Computing, Mar 2017, 2 (1), pp. 3-16. ISSN: 2377-3782, DOI: 10.1109/TSUSC.2017.2666043. 5. C. Fiandrino, F. Anjomshoa, B. Kantarci, D. Kliazovich, P. Bouvry, J. Matthews, "Sociability-Driven Framework for Data Acquisition in Mobile Crowdsensing over Fog Computing Platforms for Smart Cities," in IEEE Transactions on Sustainable Computing, May 2017, doi: 10.1109/TSUSC.2017.2702060. 6. G. Cacciatore, C. Fiandrino, D. Kliazovich, P. Bouvry, and F. Granelli, "Cost Analysis of Smart Lighting Solutions for Smart Cities", in IEEE Intenational Conference on Communications (ICC), May 2017, Paris, France. Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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Thank You! Andrea Capponi
Data Collection Utility, dsa
I
Based on number of samples already received
I
Can be defined as the following sigmoid function: dsa =
I I
1 1+e
s −ϕ ρs
a
·(−N s |t +(1− ρ2s ))
ϕs and (1 − ρs /2) coefficients control position and the speed of the incline a N s |t is the average number of samples generated from sensor s in area a: a
a
N s |t = σ · Nsa |t + (1 − σ) · N s−1 |t I
I I
Nsa |t corresponds to the number of samples collected from sensor s in timeslot t in area a a N s−1 |t is its previous value σ is the exponential weighting coefficient
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Smartphone Sensing Potential, sps I
Function of locally spent energy Es for sensing and reporting
I
Can be defined as the following sigmoid function: sps =
I I
1 1+e
− θζss ·(−Es +(1− θ2s ))
1 − θs /2 and ζs control position of the center and speed of the incline Es is the energy spent attributed to sensing (Esc ) and reporting (Esr ): Es = Esc + Esr
I I I
Esr depends on the employed communication technology (LTE or WiFi) c Esc = E s · Us Utilization context Us is defined as: ( 0, if the sensor s is used by another application Us = 1, otherwise
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Threshold δ I
I
I
Depends on the Level of battery of the devices (B) and the Amount of reported data that devices have already contributed (D) Defined as: δ = f (δb , δd ) = (δb + δd )/2 Level of battery: δb = αλ·B I I
I
α can assume arbitrary real values between [0, 1] (α = 0.7) λ > 1 (λ = 10)
Amount of reported data: 1, if D ≥ Dmax δd = D log 1 + , otherwise Dmax X D= DsW + DsL s∈S
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Evaluation Settings I
I I
FXOS8700CQ 3-axis linear accelerometer from Freescale Semiconductor BMP280 from Bosch for temperature and pressure Energy cost related to communication Esr depends on WiFi Z τtx Esr = PtxW dt 0
PtxW
= ρid + ρtx · τtx + γxg · λg
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700
650
600
550
500
450
400
350
300
250
200
150
100
50
175 150 125 100 75 50 25 0
Density
Ostermalm Traces
Time Interval (sec) Andrea Capponi | GreenDays@Sophia 2017 | Evaluation of Energy-efficient Data Collection in MCS Systems with CrowdSenSim
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