The document provides an overview of the Android operating system. It discusses Android's history as a project started by Android Inc. and acquired by Google in 2005. It describes Android's architecture based on a Linux kernel, use of the Dalvik virtual machine for apps written in Java, and open source development model. The document also covers key Android features, the app lifecycle, and development tools like the Android SDK.

1. androidOPERATING SYSTEM
A Training Report on:
Raj Kumar Goel Institute of Technology, Ghaziabad
Department of Computer Science and Engineering
- Created & Presented By
Dharmdutt Gupta

2. INDEX
 INTRODUCTION
 HISTORY OF ANDROID
 FEATURES OF ANDROID OS
 ANDROID ARCHITECTURE
 EXECUTION ENVIRONMENT AND DALVIK VIRTUAL MACHINE
 LIFE CYCLE OF ANDROID APPLICATION
 DEVELOPMENT TOOL
 CONCLUSION
 REFERENCES

3. INTRODUCTION
 A SOFTWARE PLATEFORM AND OPERATING SYSTEM FOR MOBILE DEVICES,
 FULL PHONE SOFTWARE STACK INCLUDING APPLICATIONS,
 BASED ON LINUX OPERATING SYSTEM,
 DEVELOPED BY GOOGLE AND OPEN HANDSET ALLIANCES,
 100% PURE JAVA CODE,
 AN OPEN PLATEFORM FOR DEVELOPERS, USERS AND INDUSTRY.

4. HISTORY OF ANDROID
 IN JULY, 2005, GOOGLE ACQUIRED ANDROID INC., A SMALL STARTUP COMPANY,
 STARTED AS A MOBILE SOFTWARE DEVELOPMENT COMPANY ,
 DEVELOPED A LINUX-BASED MOBILE DEVICE OS,
 ON 5TH NOVEMBER 2007, THE OPEN HANDSET ALLIANCES FOUNDED, A
CONSORTIUM OF SEVERAL COMPANIES
 FIRST RELEASED IN 2008

5. FEATURES OF ANDRIOD OS
 APPLICATION FRAMEWORK ENABLING REUSE AND REPLACEMENT OF
COMPONENET,
 DALVIK VIRTUAL MACHINE OPTIMIZED FOR MOBILE DEVICES,
 INTEGRATED BROWSER BASED ON THE OPEN SOURCE WEB KIT ENGINE,
 OPTIMIZED GRAPHICS- 2D AND 3D,
 SQLITE FOR STRUCTURED DATA STORAGE,
 MEDIA SUPPORT
 GSM TELEPHONY, BLUETOOTH, EDGE, WI-FI 3G AND 4G,
 CAMERA, GPS, COMPASS, ACCELEROMETER, GYROSCOPE ETC.,
 RICH DEVELOPMENT ENVIRONMENT.

6. ANDROID ARCHITECTURE

7. EXECUTION ENVIRONMENT AND DALVIK
VIRTUAL MACHINE
JAVA SOURCE
DOCUMENTS
COMPILE JAVA
SOURCES
USING
“JAVAC”
JAVA “CLASS”
DOCUMENTS
OUTPUT FROM
COMPILATION
PROCESS
TRANSLATE JAVA
COMPILED CLASS
FILES INTO “DEX”
FILES
EXECUTE UNDER
THE DALVIK
VIRTUAL MACHINE
CONTINUE....

8. DALVIK VIRTUAL MACHINE
 INTERPRETER OPTIMIZED FOR USE ON LOW POWERED, LOW MEMORY DEVICES
LIKE PHONES
 DOES NOT MAKE USE OF JUST IN TIME (JIT) COMPILATION TO IMPROVE THE
PERFORMANCE OF AN APPLICATION AT RUNTIME
 NOT A JAVA VIRTUAL MACHINE IT USES ITS OWN BYTECODE FORMAT CALLED
“DEX”
 ALLOWS BATTERY POWER TO BE BETTER-CONSERVED AT ALL DIFFERENT STAGES
OF EXECUTION OF AN APPLICATION
 SINCE DALVIK USES THE JAVA PROGRAMMING LANGUAGE BUT NOT THE JAVA
EXECUTION ENVIRONMENT (JVM), GOOGLE IS FREE TO DEVELOP ANDROID
WITHOUT THE NEED TO LICENSE OR OBTAIN CERTIFICATION FROM SUN
MICROSYSTEMS INC

9. LIFE CYCLE OF ANDROID APPLICATION
ACTIVITY
STARTS
onCreate()
onStart()
onResume() onPause()
onStop()
ACTIVITY IS
RUNNING
onDestroy()
ACTIVITY IS
SHUTDOWN
onRestart()
PROCESS IS
KILLED
ANOTHER
ACTIVITY
COMES
INFRONT OF
THE ACTIVITY
THE ACTIVITY
COMES TO THE
FOREGROUND
THE
ACTIVITY IS
NO LONGER
VISIBLE
USER
NAVIGATES
BACK TO
ACTIVITY
OTHER
APPLICATION
NEED MEMORY
THE ACTIVITY
COMES TO THE
FOREGROUND

10. DEVELOPMENT TOOLS
 ANDROID SDK INCLUDES A VARIETY OF CUSTOM TOOLS THAT HELP DEVELOP
MOBILE APPLICATIONS ON THE ANDROID PLATFORM
 ANDROID EMULATOR,
 ANDROID DEVELOPMENT TOOLS PLUGIN FOR THE ECLIPSE IDE
 DALVIK DEBUG MONITOR SERVICE (DDMS)
 ANDROID DEBUG BRIDGE (ADB),
 ANDROID ASSET PACKAGING TOOL (AAPT),
 SQLITE3,
 TRACE VIEW,
 ACTIVITY CREATOR ETC.

11. CONCLUSION
 ANDROID IS OPEN TO ALL: INDUSTRY, DEVELOPERS AND USERS,
 PARTICIPATING IN MANY OF THE SUCCESSFUL OPEN SOURCE PROJECTS,
 AIMS TO BE AS EASY TO BUILD FOR AS THE WEB,
 GOOGLE ANDROID IS STEPPING INTO THE NEXT LEVEL OF MOBILE INTERNET.
ANDROID IS A TRULY OPEN, FREE DEVELOPMENT PLATFORM BASED ON LINUX
AND OPEN SOURCE. HANDSET MAKERS CAN USE AND CUSTOMIZE THE PLATFORM
WITHOUT PAYING A ROYALTY.
A COMPONENT-BASED ARCHITECTURE INSPIRED BY INTERNET MASH-UPS.
PARTS OF ONE APPLICATION CAN BE USED IN ANOTHER IN WAYS NOT ORIGINALLY
ENVISIONED BY THE DEVELOPER. CAN EVEN REPLACE BUILT-IN COMPONENTS
WITH OWN IMPROVED VERSIONS. THIS WILL UNLEASH A NEW ROUND OF
CREATIVITY IN THE MOBILE SPACE.

12. REFERENCES
 WHITE PAPER FOR “A SPECTRUM WHITE PAPER: THOUGHTS ON GOOGLE
ANDROID” FROM SPECTRUM DATA TECHNOLOGY. http://www.spectrumdt.com
 http://code.google.com/android/ - GOOGLE ANDROID OFFICIAL WEBPAGE
 http://www.openhandsetalliance.com/ - OPEN HANDSET ALLIANCE WEBPAGE
 http://en.wikipedia.org/wiki/Android_(mobile_phone_platform) –WIKIPEDIA
INFORMATION
 http://googleblog.blogspot.com/ - OFFICIAL GOOGLE BLOG