quartz/content/notes/06-challenges-for-ubicomp-and-intro-to-sensors.md

title	tags
06-challenges-for-ubicomp-and-intro-to-sensors	lecture info305

Challenges

• What’s difficult about Ubiquitous Computing?
  • Requires understanding of sensors and new sensing technologies
    • Noisy inputs
    • Sensor fusion
• Wireless communication channels
• Power consumption
• Context is only a proxy for human intent
  • Unpredictable ussage context in particular for mobile devices
• Require novel user interfaces, limited/different I/O capabilities
  • Lack of standardization in interface patterns
• Privacy & Security

Wireless Communication Channels

• 
• Unpredictable availability and throughout
• Many physical issues:
• Refraction
• Absorption
• Antenna Geometry
• Power Limits
• Wireless spectrum is highly contested
• Many sources of interference
• Limited bandwith available
• Often complext SW/HW stacks

Power Consumption

• Biggest energy consumers
  • Display (backlight)
  • Wireless modules
  • GPS receiver, cameras
  • Sensors (touch, accelerometer, IMU)
• Limited power supply
  • Tradeoff: capacity vs. size/weight/portability
  • Energy consumption becomes important
• Two solutions:
  • Increase energy in relation to size/weight
    • Requires chemistry & physics knowledge
  • Decrease energy consumption
    • Requires CS/IS/EE knowledge
• 

Privacy and Security

• Context awareness requires huge amounts of private & personal data (see current generation mobile devices)
  • Emails, contacts
  • Sensor data, movement profiles
  • PIN/TAN codes
  • Photos
• Many people want to access data
  • Google, Facebook, Microsoft (> ads)
  • NSA, GCHQ, BND, Five Eyes (> crime prevention)
  • Hackers (> extorsion, stealing your money)
• Problem 1: No pervasive encryption
• Problem 2: Voluntary use of cloud services, interconnected services

Sensors

need to capture context information to build context aware systems

smartphone sensors

• Smartphones house highly integrated sensors for sensing the environment:
• Proximity Sensors (e.g. NFC, Cameras)
• Location sensors (e.g. Cell,. AGPS, WiFi, GSM, Cameras)
• Orientation Sensors (e.g. Magnetometer, Accelerometer, Gyroscope, Camera)
• 3D sensors (LiDAR, Cameras)
• Microphone
• Lux-meter
• Future smartphones likely to add more:
• Kinect (e.g., Primesense Capri, Motorola Tango)
• RTK GPS
• Health sensors (glucose sensor, heart rate monitor,..)

head mounted displays

• Head-mounted displays (e.g. Hololens, Snap Spectacles) house highly integrated sensors for sensing the environment:
• Location sensors (e.g. 2 x cameras and depth camera)
• Orientation Sensors (e.g. Magnetometer, Accelerometer, Gyroscope, Camera)
• Microphone
• Lux-meter
• Eye tracking cameras