Android-01 Introduction to Mobile Operating System

What is Mobile OS?

• A Mobile Operating System (Mobile OS) is an operating system designed specifically for mobile devices such as smartphones, tablets, smartwatches, and other handheld devices.
• It controls the overall functioning of the device and acts as an interface between hardware and applications.
• Without a Mobile OS, a smartphone cannot operate or run applications.

What Mobile OS Does

• A Mobile Operating System manages device hardware and software resources.
• It allows users to install and run applications.
• It manages memory, processor, storage, and connectivity features.
• Examples of Mobile Operating Systems include Android and iOS.

Features of Mobile OS

• Touch Screen Support
  • Mobile OS supports touch gestures like tap, swipe, and scroll for easy interaction
  • It provides a simple and user-friendly interface for smooth navigation
• Multitasking Support
  • It allows multiple applications to run at the same time efficiently
  • Users can switch between apps without interrupting their work
• Connectivity Support
  • It supports Wi-Fi, Bluetooth, mobile networks, and internet services
  • Enables communication, data transfer, and online activities
• Application Management
  • It allows users to install, update, and remove applications easily
  • Supports app stores like Play Store and App Store
• Resource Management
  • It manages RAM, CPU, battery, and storage efficiently
  • Helps improve performance and reduce power consumption

Constraints of a Mobile Operating System

• Limited Battery Power
  • Mobile devices depend on battery which drains quickly during continuous usage
  • Heavy applications, games, and background processes consume more power
• Limited RAM
  • Mobile devices have less memory compared to computers which affects performance
  • Running many applications at once can slow down the system
• Limited Storage Space
  • Storage capacity is limited and gets filled by apps, photos, and videos
  • Users often need to delete unnecessary data to maintain free space
• Small Screen Size
  • Mobile devices have small screens which limit the display of information
  • Not suitable for complex tasks like detailed editing or multitasking
• Limited Processing Power
  • Mobile processors are less powerful than desktop processors
  • Heavy tasks and applications can reduce speed and performance

Requirements of a Mobile OS

• Touch Screen Support

  • Mobile OS supports touch gestures like tap, swipe, and scroll for easy interaction
  • It provides a simple and user-friendly interface for smooth navigation

• Multitasking Support

  • It allows multiple applications to run at the same time efficiently
  • Users can switch between apps without interrupting their work

• Connectivity Support

  • It supports Wi-Fi, Bluetooth, mobile networks, and internet services
  • Enables communication, data transfer, and online activities

• Application Management

  • It allows users to install, update, and remove applications easily
  • Supports app stores like Play Store and App Store

• Resource Management

  • It manages RAM, CPU, battery, and storage efficiently
  • Helps improve performance and reduce power consumption

Types of Mobile OS

• Android

  • Android is a Linux-based mobile operating system developed by Google.
  • It is open-source and highly customizable.
  • It is widely used in smartphones and tablets from various manufacturers such as Samsung, Vivo, Oppo, etc.
  • Android supports a large number of applications through the Google Play Store.
  • It is currently the most widely used mobile operating system in the world.

• iOS

  • iOS is a mobile operating system developed by Apple Inc.
  • It is used exclusively in Apple devices such as iPhone and iPad.
  • It is a closed-source operating system.
  • iOS is known for its strong security, smooth performance, and optimized user experience.
  • Applications are downloaded through the Apple App Store.

• BlackBerry OS

  • BlackBerry OS was developed by BlackBerry Ltd.
  • It was mainly used in BlackBerry smartphones.
  • It was popular for its high-level security and business features.
  • It was widely used by corporate and government organizations.
  • It is now discontinued and no longer in active use.

• Windows Phone

  • Windows Phone was developed by Microsoft.
  • It was used in devices such as Nokia Lumia.
  • It featured a tile-based user interface.
  • It offered integration with Microsoft services.
  • It is now discontinued due to low market share.

• Symbian OS

  • Symbian OS was developed mainly by Nokia.
  • It was one of the earliest smartphone operating systems.
  • It was widely used in early Nokia smartphones.
  • It supported basic smartphone features and applications.
  • It is now obsolete and replaced by modern operating systems.

Comparison between Android and iOS

Feature	Android	iOS
Developer	Developed by Google	Developed by Apple Inc.
Source Type	Open-source operating system	Closed-source operating system
Device Support	Used by many manufacturers like Samsung, Oppo, Vivo	Used only in Apple devices such as iPhone and iPad
Customization	Highly customizable with themes, widgets, launchers	Limited customization options
App Store	Google Play Store	Apple App Store
Security	Good security but more open to third-party apps	Very high security with strict app policies
User Interface	Varies depending on manufacturer	Uniform and consistent interface
Software Updates	Updates depend on device manufacturer	Updates provided directly by Apple
Market Share	High global market share	High but lower than Android

History and versions of the Android OS

History of Android Operating System

• Android was founded by Andy Rubin in 2003 and was initially developed for digital cameras
• Google acquired Android in 2005 and shifted its focus from cameras to smartphones
• The name "Android" comes from Andy Rubin’s nickname
• The first Android smartphone was launched in 2008 (HTC Dream)
• Android is developed by Google along with the Open Handset Alliance (OHA)

Android Versions

• Android started with version 1.0 in 2008 and has evolved continuously with new features and improvements
• Early versions like Android 1.0 and 1.1 did not have dessert names
• From Android Cupcake to Android Pie, versions were named alphabetically based on desserts
• From Android 10 onwards, public dessert names were removed but internal codenames still exist
• Each new version focuses on better performance, improved security, enhanced UI, and support for new devices

Evolution of Android Versions

• Android 1.0 - 1.1 (2008-2009): Introduced basic smartphone functionality, Android Market, Gmail, Google Maps, browser, and camera support.
• Android 1.5 Cupcake - 2.3 Gingerbread (2009-2010): Added on-screen keyboard, widget support, improved browser performance, better UI, and NFC support.
• Android 3.0 - 3.2 Honeycomb (2011): Specifically designed for tablets with improved large-screen interface and system bar.
• Android 4.0 Ice Cream Sandwich - 4.4 KitKat (2011-2013): Unified phone and tablet platforms, improved multitasking, refined UI, and enhanced performance.
• Android 5.0 Lollipop - 7.0 Nougat (2014-2016): Introduced Material Design, ART runtime, split-screen multitasking, better notifications, and battery optimization.
• Android 8.0 Oreo - 9.0 Pie (2017-2018): Focused on background process limits, notification channels, AI-based features, and improved system performance.
• Android 10 - 13 (2019-2022): Removed public dessert names, introduced dark mode, gesture navigation, advanced privacy controls, and foldable device support.
• Android 14 - 16 (2023-2025): Focused on enhanced security, customization, AI integration, performance improvements, and better large-screen and foldable support.

Android Architecture

Introduction

• Android Architecture is a layered software stack that manages mobile device hardware and provides a platform for applications
• Each layer performs a specific function and all layers work together to run Android applications efficiently and smoothly

Explanation of Layers

1. Linux Kernel

• It is the base and lowest layer of Android Architecture
• It manages memory, power management, process management, and device drivers
• It acts as a bridge between hardware and software components and ensures proper communication

2. Native Libraries

• This layer contains important system libraries written in C and C++
• These libraries provide support for database, graphics, and multimedia features
• Examples include WebKit for browser support, SQLite for database, OpenGL for graphics, Media libraries for audio and video, and FreeType for font support

3. Android Runtime

• Android Runtime includes core libraries and Dalvik Virtual Machine (DVM)
• It is optimized for mobile devices and uses less memory than JVM
• It is responsible for executing Android applications and managing their performance

4. Application Framework

• It provides APIs and system services used for application development
• It manages components such as activities, resources, and content providers
• It includes Activity Manager, Window Manager, Resource Manager, and other services

5. Applications

• It is the topmost layer of Android Architecture
• It includes built-in applications and user-installed applications
• These applications use the Android framework to perform different tasks

Conclusion

• Android Architecture consists of multiple layers from Linux Kernel to Applications
• Each layer has a specific role and supports the upper layer
• This layered structure ensures better performance, flexibility, and smooth functioning of Android applications

Android Activity Lifecycle

Introduction

• In Android, an Activity represents a single screen with a user interface.
• The Activity Lifecycle refers to the different states an activity goes through from its creation to its destruction.
• Android manages these states using predefined lifecycle methods.
• Understanding the Activity Lifecycle helps developers manage resources properly and build efficient applications.

What is Activity Lifecycle

• The Activity Lifecycle is a sequence of callback methods that are triggered when an activity changes its state.
• These methods are called by the Android system depending on user interaction and system events.
• It ensures proper memory management and smooth switching between activities.

Lifecycle Methods

1. onCreate()

• It is called when the activity is created for the first time
• It is used to initialize components such as UI elements, variables, and resources required for the activity
• The layout of the activity is usually set using setContentView() in this method
• This method is executed only once during the entire lifecycle of the activity

2. onStart()

• It is called after the onCreate() method is executed in the activity lifecycle
• In this stage, the activity becomes visible on the screen to the user but is not yet ready for interaction
• It is mainly used to prepare the activity to move into the foreground and become fully active

3. onResume()

• It is called when the activity comes to the foreground and becomes fully active
• In this state, the user can interact with the activity and perform actions
• It is used to start operations like animations, sensors, or services that need to run while the activity is active

4. onPause()

• It is called when the activity is partially hidden because another activity comes in front of it
• In this state, the activity is still visible but not in focus and user interaction is paused
• It is used to pause ongoing tasks, save temporary data, and release limited resources

5. onStop()

• It is called when the activity is completely hidden from the user and no longer visible on the screen
• This happens when another activity fully covers it or the user navigates away from it
• It is used to release heavy resources such as camera, network connections, or background processes

6. onRestart()

• It is called when a stopped activity is about to start again and come back to the foreground
• It is triggered after onStop() and before onStart()
• It is used to reinitialize components or restore the state of the activity

7. onDestroy()

• It is called before the activity is destroyed and removed from memory
• It is used to perform final cleanup operations and release all remaining resources
• This method is the final stage of the activity lifecycle

Conclusion

• The Activity Lifecycle consists of multiple methods that manage the different states of an activity.
• Proper handling of lifecycle methods ensures better performance, efficient resource management, and a smooth user experience in Android applications.

Generalized Architecture of Mobile Operating System

Introduction

• Android Architecture is a layered software stack that manages mobile device hardware and software components.
• Each layer performs a specific function and works together to run Android applications efficiently and smoothly.

Explanation of Layers

1. Kernel Layer

• It is the core and lowest layer of Android Architecture.
• It is based on the Linux kernel and acts as a bridge between hardware and software.
• It manages memory, CPU scheduling, power management, process management, and device drivers.
• It also provides security and handles communication with hardware components. 2. Hardware Abstraction Layer (HAL)
• It acts as an interface between hardware components and the Android operating system.
• It hides the complexity of hardware details from the upper software layers.
• It allows Android to run on different hardware devices without making major changes in the system. 3. Middleware
• It provides common services and system libraries required by applications.
• It includes multimedia support, database services, networking, and security services.
• It helps applications communicate with hardware through standard system APIs. 4. Application Framework
• It provides APIs and system services used by developers to build Android applications.
• It manages activities, notifications, resources, and content providers.
• It includes important managers such as Activity Manager, Window Manager, and Resource Manager. 5. User Interface Layer
• It is the topmost layer of the Android Architecture.
• It handles display, screen layout, and user interaction through touch and gestures.
• It includes system applications and user-installed applications.

Conclusion

• Android Architecture follows a structured layered model from Kernel to User Interface.
• Each layer has a specific role, ensuring efficient performance, proper security, and smooth functioning of Android devices.

Explain the Building Blocks of Android Application.

Introduction

• Android applications are built using different components known as building blocks
• These components define how an application works, interacts, and manages data
• Each component has a specific role in the application

Building Blocks of Android Application

1. Activity

• Activity represents a single screen with a user interface
• It is the main entry point for user interaction in an application
• Example: Login screen, Home screen
• Managed using Activity Lifecycle methods

2. View

• View is the basic building block of user interface components
• It represents UI elements such as TextView, Button, EditText, etc.
• Used to display information and handle user interaction

3. Intent

• Intent is a messaging object used to communicate between components
• It is used to start activities, services, or broadcast receivers
• It can also be used to pass data between components

4. Service

• Service is a component that runs in the background without user interface
• Used for long-running operations such as music playback or downloading data
• It continues running even when the app is not in use

5. Content Provider

• Content Provider is used to manage and share data between different applications
• It provides a standard interface to access structured data
• Example: Contacts, media files

6. Fragment

• Fragment is a reusable part of user interface inside an activity
• It helps in creating dynamic and flexible UI
• It works as a small part of a screen within an activity

7. AndroidManifest.xml

• It is a configuration file that contains information about the application
• It declares components, permissions, and app details
• It is required for every Android application

Conclusion

• Building blocks are essential components used to develop Android applications
• Each component has a specific function and works together with others
• Proper use of these components helps in creating efficient and well-structured applications

Features of Android Operating System

1. Open Source Platform

• Android is an open-source operating system which allows developers to modify and customize it
• It provides flexibility to manufacturers and developers to create customized applications and devices

2. User-Friendly Interface

• Android provides a simple and easy-to-use interface
• It supports touch gestures like tap, swipe, and scroll for better user experience

3. Multitasking

• Android allows multiple applications to run at the same time
• Users can switch between apps easily without closing them

4. Connectivity

• Android supports various connectivity options such as Wi-Fi, Bluetooth, GSM, CDMA, and mobile data
• It enables communication, internet access, and data transfer

5. Large Number of Applications

• Android provides access to a wide range of applications through the Play Store
• Users can download apps for entertainment, communication, productivity, and more

6. Multimedia Support

• Android supports audio, video, and image formats
• It allows users to watch videos, listen to music, and view images easily

7. Customization

• Android allows users to customize home screen, themes, widgets, and settings
• It provides high level of personalization

Advantages of Android Operating System

1. Wide Device Availability

• Android is used by many manufacturers like Samsung, Vivo, Oppo, etc.
• It is available in different price ranges from budget to premium devices

2. High Customization

• Users can customize almost every aspect of the device
• Developers can also build customized apps and ROMs

3. Large Developer Community

• Android has a large number of developers worldwide
• This results in continuous updates, support, and availability of apps

4. Integration with Google Services

• Android is well integrated with Google services like Gmail, Google Maps, YouTube, and Google Drive
• It improves productivity and user experience

5. Cost Effective

• Android devices are available at lower cost compared to other operating systems
• It makes smartphones accessible to a large number of users

6. Easy App Development

• Android provides powerful tools like Android Studio and SDK
• Developers can easily build, test, and deploy applications

Constraints of Smart Mobile OS

• Limited Battery Power

  • Mobile phones run on battery
  • Battery drains fast
  • Heavy apps and games consume more power

• Limited RAM (Memory)

  • Mobile devices have less RAM than computers
  • Too many apps make phone slow
  • Background apps are closed automatically

• Limited Storage Space

  • Mobile storage is limited
  • Apps, photos, videos fill memory quickly
  • User needs to delete data often

• Small Screen Size

  • Mobile screens are small
  • Limited space to display information
  • Not suitable for long work like desktop

• Limited Processing Power

  • Mobile processors are less powerful
  • Heavy tasks reduce performance
  • Apps must be optimized

Comparison of Mobile Operating Systems

Feature	Android	iOS	BlackBerry	Windows Mobile	Symbian
Developer	Google	Apple	BlackBerry	Microsoft	Nokia
Source Type	Open	Closed	Closed	Closed	Open
App Store	Play Store	App Store	BB World	Windows Store	Ovi Store
Security	Moderate	High	Very High	Moderate	Low
Customization	High	Low	Low	Low	Moderate
Market Share	High	High	Very Low	Negligible	Obsolete

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Questions

1. Define Mobile Operating System.
2. State the requirements of a Mobile Operating System.
3. List different types of Mobile Operating Systems.
4. Write short note on history of Android OS.
5. What is Activity Lifecycle?
6. Explain constraints of Smart Mobile Operating System.
7. Explain generalized architecture of Mobile OS.
8. Explain Android Architecture in brief.
9. Explain building blocks of Android Application.
10. Differentiate between Android OS and iOS.