2. OpenSignal @jamescrr
Coming to a lecture theatre near you
1. Mobile sensors beat Human sensors
2. Mobile sensors are getting better.*
3. Mobile measures more than you think.
*humans aren’t.
OpenSignal & WeatherSignal sensor networks on 7m phones
3. OpenSignal @jamescrr
Man made Data
“Man is the measure of all things” - Protagoras
“In those days Caesar Augustus issued a decree
that a census should be taken of the entire
Roman world.” - NIV Bible
The Cheugugi rain gauge, Korea.
“that which no canvas sails could withstand” -
Force 12, the Beaufort Scale.
Chronicles. Annals. Diaries. Newspapers. Civil
records. Facebook. Twitter.
Da Vinci’s Schema delle Proporzioni
4. OpenSignal @jamescrr
Mobile Sensors & Repurposing
Fingerprint scanner
Heartrate
RGB Ambient Light
Relative humidity
Env. temperature
Barometer
NFC
Gyroscope
Accelerometer
Bluetooth radio
WiFi radio
FM radio
Cell radio
Front camera
Rear camera
GPS
Magnetic field
Light flux
Battery temp.
Microphone
Touch
S I S II S III S4 S5
Images from iFixit and forthcoming OpenSignal Sensor iIbrary
5. OpenSignal @jamescrr
Man vs Mobile
No artwork is enhanced by the addition of clipart.
It’s quite
warm.
It’s 26.2°C
Man is:
• Imprecise
• Low accuracy
• Limited range
• Magnetism?
• Not good at logging
6. OpenSignal @jamescrr
Mobile Sensors are getting better
New, Smarter, More Efficient
• New raw sensors (gas, sweat, heartrate)
• New virtual sensors offer context
awareness & more (pedometer, activity
recognition, significant motion)
• Efficiency of mobile sensing increasing
(co-processors/sensor batching)
7. OpenSignal @jamescrr
Outdoor temperature from phone batteries
All phones have
battery temperature
sensors
Lots of things influence
the battery
temperature
Including outdoor air
temp.
9. OpenSignal @jamescrr
Do People Like Obama?
• WiFi routers are
occasionally named
to express political
opinions
• We found 1140
WiFis referencing
Obama in May
2012
• Net +ve sentiment
• Other WiFi tricks:
net discovery.
10. OpenSignal @jamescrr
When do we get up?
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
0.0
0.2
0.4
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
−0.25
0.00
0.25
0.50
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour
Weekdays – 8 am Weekends – 10 am
We modeled US LTE speeds with linear regression, variables included signal
quality and factors for hour of day.
11. OpenSignal @jamescrr
How much do I use my phone?
Feb Mar AprJanDec
0
5
10
15
20
• Number of times
I turn on my
Galaxy S4
screen per hour.
• Darkest blue is
50.
• GS4 is not my
only phone.
12. OpenSignal @jamescrr
The World is now your Lab
Mobiles sensors:
• pre-existing
• maintenance free
• continually upgraded
piece of scientific apparatus, capturing
unparalleled detail on the environment &
human activities.
Challenges
• Capabilities of mobile exceed the
ambition of app developers
• No Higgs boson sensor yet
Your device can be a nut in a scientific apparatus larger than the LHC
