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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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The IoT is Growing at an Exciting Pace
Source: https://iot-analytics.com/state-of-the-iot-update-q1-q2-2018-number-of-iot-d evices-now-7b/
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Moore’s Law: IC transistor count doubles every 18-24 mo
Photo Credit: Intel
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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1 – Number of computers per person grows
Mainframe
[Bell et al. Computer,
1 per Enterprise
1972, ACM, 2008]
Workstation
1 per Engineer
Laptop
Mini Computer
1 per Company
1 per Professional
Smart Sensors
Ubiquitous
100 – 1000’s per person
Personal Computer
1 per Family
1 per person
Smartphone
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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log (people per computer)
2 – Computer volume shrinks by 100x every decade
Mainframe
1 per Enterprise
Workstation
1 per Engineer
Laptop
[Nakagawa08]
Mini Computer
1 per Company
1 per Professional
Smart Sensors
Ubiquitous
100 – 1000’s per person
Personal Computer
1 per Family
1 per person
Smartphone
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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100x smaller every decade
3 – Prices fall dramatically
Mainframe
Workstation
Number Crunching Data Storage
Laptop
productivity interactive
Mini Computer
streaming Smart information
Personal Computer
Sensors to/from the physical
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Smartphone world Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Bell’s Law:
A new computer class every decade
“Roughly every decade a new, lower priced computer class forms based on a new programming platform, network, and interface resulting in new usage and the establishment of a new industry.”
– Gordon Bell [1972,2008]
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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What is driving Bell’s Law?
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Different radio technologies
Source https://www.advantech.eu/resources/featured-article/de95b961-268f-4535-9943-ffa597b80671
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Higher Power
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Established Comms Interfaces
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Emerging Comms Interfaces
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Types of Processing Unit
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Types of Processing Unit (2)
Microprocessor vs FPGA
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Example of Microcontrollers
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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RF Transceiver Characteristics
VERY IMPORTANT FOR NETWORK PERFORMANCE EVALUATION!!!
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Transceiver Characteristics
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Transceiver States
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Power Consumption
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RADIO
SENSOR CPU TX RX IDLE
SLEEP
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
Power Consumption for Communication
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Power Consumption
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
More Accurate Formula
(E. Shih et al.,”Physical Layer Driven Protocols and Algorithm Design for Energy-Efficient Wireless Sensor Networks”, ACM MobiCom, Rome, July 2001)
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Power Consumption for Communications
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Start-up Power and Start-up Time
Energy vs Packet Size
Energy per
bit (pJ)
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Start-up Time and Sleep Mode
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Power Consumption in Computation
Wang/Chandrakarasan: Energy Efficient DSPs for Wireless Sensor Networks. IEEE Signal Proc. Magazine, July 2002.
The power consumption in data processing (Pp) is
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Power Consumption in Computation (2)
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Some Energy Consumption Figures
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Memory power consumption
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
Computation vs. Communication Energy Cost
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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A Simple Energy Model
A Simple Energy Model
ETx (k,D)
ETx (k,D) = ETx-elec (k) + ETx-amp (k,D) ETx (k,D) = Eelec * k + eamp * k * D2
ERx (k) = ERx-elec (k) ERx (k) = Eelec * k
D
k bit packet
Transmit Electronics
Tx Amplifier
Eelec * k
eamp* k* D2
Operation
Energy Dissipated
Transmitter Electronics ( ETx-elec) Receiver Electronics ( ERx-elec)
( ETx-elec = ERx-elec = Eelec )
50 nJ/bit
Transmit Amplifier {eamp}
100 pJ/bit/m2
ERx (k)
k bit packet
Receive Electronics
Eelec * k
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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ETx-elec (k)
ETx-amp (k,D)
Example Using the Simple Energy Model
What is the energy consumption if 1 Mbit of information is transferred from the source to the sink where the source and sink are separated by 100 meters and the broadcast radius of each node is 5 meters? Assume the neighbor nodes are overhearing each other’s broadcast
100 meters / 5 meters = 20 pairs of transmitting and receiving nodes (one node transmits and one node receives)
ETx (k,D) = Eelec * k + eamp * k * D2
ETx = 50 nJ/bit . 106 + 100 pJ/bit/m2 . 106 . 52 = = 0.5J + 0.0025 J = 0.0525 J
ERx (k,D) = Eelec * k ERx = 0.05 J
Epair = ETx + ERx = 0.1025J
ET = 20 . Epair = 20. 0.1025J = 2.050 J
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Comparison
Energy Startup per bit time
Idle current
Technology
Data Rate
Tx Current
Energy per bit
Idle Current
Startup time
Mote
76.8 Kbps
10 mA
430 nJ/bit
7 mA
Low
Bluetooth
1 Mbps
45 mA
149 nJ/bit
22 mA
Medium
802.11b
11 Mbps
300 mA
90 nJ/bit
160 mA
High
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Dr. Francesco Restuccia, EECE5155 Wireless Sensor Networks and the Internet of Things
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Bluetooth
Mote
IEEE 802.11
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