Exam 1 Flashcards
Mobile Market Share
Worldwide:
Android ~ 70%
iOS ~ 29%
USA:
Android ~38%
iOS ~ 61%
Low-Band spectrum
under 3 GHz
Usage of 99.7%
provides most range
High-Band spectrum
above 24 GHz
yards not miles
larger capacity + ultra fast speeds
Mid-Band spectrum
3-24 GHz
blend of low + high characteristics
GSM
Global System for Mobile Communications
CDMA
Code Division Multiple Access
FCC (Spectrums)
Spectrum is finite
FCC oversees spectrum allocation
raises money for U.S treasury, auctions with bids for frequencies
NFC (Near Field Communication)
Range of few cms
Sends encrypted data
UWB (Ultra Wide Band)
“pulse radio”
Short range, high bandwidth / data rates
30-600 feet, 700+ Mbps
centimeter level accuracy
Time of Flight // Angle of Arrival
Camera
Used to detect motion
Facial recognition
Augmented Reality
Microphone
Sound detection
Fingerprint Sensor
Biometric authentication
Heart Rate Sensor
LED emits light towards the skin,
sensor looks for the light waves
reflected by it. Heartbeat measured by counting the changes in light intensity between the minute pulsations of the blood vessels.
Motion Sensors
Measure acceleration forces and rotational forces along three axes
Environmental Sensors
Measure various environmental parameters of the surrounding area of the device
Position Sensors
Measure physical position of a device.
Accelerometer
Axis-based motion sensing. Senses the changes in
the orientation of smartphones with respect
to x, y, and z-axis
Gives orientation as to the way a device is held
Measures movement(acceleration)
Uses:
○ Switches apps from portrait to landscape
○ Can tell if phone is facing up or down
○ Shows your speed in a driving app
○ Motion & shake detection
○ Track Steps for Fitness apps
Gyroscope
measures angular rotation across 3 axes
Detects how much the phone is titled or rotated
Provides directional orientation details -> Up/down and left/right
Usages:
○ Pokemon go
○ Google Sky Map
precision for 360 photo spheres images
Tilt steering in racing games
Ambient Light Sensor
detects the light around your environment
can adjust screen brightness
Barometer Sensor
measures air pressure
○ detects weather changes
○ Detects distance from sea level or your altitude
○ Increases accuracy in fitness apps, like step tracking
Ambient Temperature Sensor
measures air temperatures of immediate
surrounding
- Not in all phones
Ambient Humidity Sensor
Measure humidity of an environment
Monitors dewpoint
- Not in all phones
Geiger Counter
Measures radiation level in area
- rare
Proximity Sensor
usually located near the top speaker
combines an infrared LED & light detector to know how close the phone is to an object
- Know when your phone is closer to your face to turn off
the screen - The sensor emits a light beam (invisible to the
human eye), which bounces back to the device
Magnetometer
measures changes in Earth’s magnetic fields
thus detects which way is North
○ in Maps, uses this to work out which way up the map
should be
○ works with standalone compass apps
○ Detects metals…metal detector apps
- Primary purpose is working with accelerometer and
GPS unit to figure out where you are in the world &
where you’re pointing
GPS Sensor
A GPS chip in our phones ping multiple satellites in space to figure out a device’s location
○ based upon angles of intersection
Doesn’t use the phone’s data
Interference from indoors or heavy cloud cover can
cause locations to not be locked in
Does drain the battery
Distance to cell towers can also be used to approximate
where the device is (Assisted GPS)
Used for navigation, geo-fencing, gaming, augmented
reality & more
Geofencing
Location-based service to trigger a pre-programmed action when a device enters or exists a virtual boundary set up around a geographical location (geofence)
Virtual boundary can simply be a radius (10 miles or 30 feet) from
a specific location
Used to monitor and automate business process
Geostationary Earth Orbit (GEO)
Orbit: 22,300 miles from Earth
Num of Satellites: 8
Orbit in fixed position above Earth’s equator
Middle Earth Orbit (MEO)
Orbit: 6,000 + miles from Earth
Num of Satellites: Usually 10 - 12. varies
Satellites move with respect to a point on Earth
Low Earth Orbit (LEO)
Orbit: 400 - 700 miles from Earth
Num of Satellites: Many (40 - 80 some cases for global coverage
Satellites rapidly move with respect to a point on Earth. Also must be tracked by recievers
Native Apps
Application specifically written and installed on a
platform/Operating System
Native App cannot be installed on other platforms. iOS != Android
Cross-Platform Development Frameworks
Building a single codebase that can support and run on multiple platforms
For Example:
code used to develop an app for a specific OS, like Android, becomes reusable for iOS
Framework Options: React Native, Flutter, Xamarin, Ionic
Cons: Slower than Native Apps
Mobile Web Apps
Mobile Web Apps are website applications designed & optimized to specifically render better in the browser on mobile devices
- Made to fit the smaller screen size
- Provide easier to use navigational elements
- No home screen icon
- Can save a link to the site, to ”bookmark” and
create an icon to launch the app in a mobile
browser
Responsive Design Approach
The web page is loads and is stretched & contracted based upon:
- the size of the screen
- as the user increases/decreases the size of their browser
- Same display code for both desktop & mobile views
- One experience for all platforms
- One code base for team to maintain\
- Leverages technologies like:
HTML
CSS
JavaScript
Hybrid Apps
Combination of a native app and web app
- Developed as a web app in a native container
- A native app that uses a ‘web view’ control to receive
HTML/CSS/JS of a mobile web app - Essentially, a responsive design web app that is wrapped
and packaged like a Native app - Is distributed through App Repositories to be downloaded & have a home screen icon
- Device sensors and components can be used to access native device APIs for device components
- Framework: Apache Cordova
Native App Pros
Best user experience (smoother, faster, richer UX)
Can utilize all device sensors, components
Direct access to native APIs for quick data
processing & faster app load times
Robust offline capabilities
Can do push notifications
Can place app into the App Repository
Visual footprint on device screen
Native App Cons
Can’t port from one platform to the next
No Code Reusability
Double the time/cost to support multiple platforms
Maintaining team with multiple skillsets
Fragmentation: have to support of many different
versions of one platform
Difficult to learn & build
App Repository drawbacks
Revenue Sharing through Commissions
Never truly under your control; subject to approvals
○ App Repository removal if not updating regularly
Will always need the vendor to distribute the app
Mobile Web App Pros
Easy to create/maintain app
install once, accessed by all platforms
Tools readily available
Can get current location of device
Can provide offline features
Can be viewed on any mobile web browser
Mobile Web App Cons
Have to refresh webpage to get updated location
Device sensors/components unavailable
Like desktops, have to support multiple browsers
Offer limited user experience compared to native apps
Desktop content reformatted for mobile view
Page loads slower due to network latency
Can’t do push notifications
Hybrid App Pros
Visual shortcut on device screen
Can do push notifications
Don’t need a web browser like mobile web apps
Have access to device capabilities & APIs
Single codebases
Hybrid App Cons
Much slower than Native apps, but could be slightly
faster than Mobile Web apps
Have to face cons associated with both Native and
Mobile Web apps
Still not optimal rich user experience like Native
App Repository Comissions
App Repos take 30% of Digital Goods (15% if app
store sales are less than $1 million/year), including:
- App purchases
- In-App Purchases:
- gems, coins, books, music, video
- Subscriptions (Netflix, Spotify)
- Subscription falls to 15% after 1 year
- In- App Advertisements
They don’t take 30% of ‘real world goods’
- Physical goods or services
- Shipped products like from Amazon (shirts, hats, etc.)
- Uber/Lyft rides
- Tickets to events or movies
