04-04-2012, 04:00 PM
Android operating system
vidya sem.zip (Size: 490.88 KB / Downloads: 60)
INTRODUCTION
Android is a software stack for mobile devices that includes an operating system, middleware and key applications. Android is a software platform and operating system for mobile devices based on the Linux operating system and developed by Google and the Open Handset Alliance.
1.1. THE BIRTH OF ANDROID
1.1.1. Google Acquires Android Inc.
In July 2005, Google acquired Android Inc., a small startup company based in Palo Alto, CA. Android's co-founders who went to work at Google included Andy Rubin (co-founder of Danger), Rich Miner (co-founder of Wildfire Communications, Inc), Nick Sears (once VP at T-Mobile), and Chris White (one of the first engineers at WebTV).
1.1.2. Open Handset Alliance Founded
On 5 November 2007, the Open Handset Alliance, a consortium of several companies which include Google, HTC, Intel, Motorola, Qualcomm, T-Mobile, Sprint Nextel and NVIDIA, was unveiled with the goal to develop open standards for mobile devices.
1.1.3. Android was released on May 2008
Google has unveiled at least three prototypes for Android, at the Mobile World Congress on February 12, 2008. One prototype at the ARM booth displayed several basic Google applications.
1.2. FEATURES
1.2.1. Application Framework
It is used to write applications for Android. Unlike other embedded mobile environments, Android applications are all equal, for instance, an applications which come with the phone are no different than those that any developer writes.The framework is supported by numerous open source libraries such as openssl, SQLite and libc.
1.2.2. Dalvik Virtual Machine
It is extremely low-memory based virtual machine, which was designed especially for Android to run on embedded systems and work well in low power situations.
1.2.3. Integrated Browser
Google made a right choice on choosing WebKit as open source web browser. They added a two pass layout and frame flattening. Two pass layout loads a page without waiting for blocking elements.
1.2.4. Optimized Graphics
As Android has 2D graphics library and 3D graphics based on OpenGL ES 1.0, possibly we will see great applications like Google Earth and spectacular games like Second Life
1.2.5. SQLite
Extremely small (~500kb) relational database management system, which is integrated in Android.
1.2.7. Data Storage
SQLite is used for structured data storage .SQLite is a powerful and lightweight relational database engine available to all applications.
1.2.8. Connectivity
1.2.9. Messaging
1.2.10. Web Browser
1.2.11. Java Virtual Machine
1.2.12. Media Support
Additional Hardware Support
1.2.14. Development Environment
CHAPTER 2
DETAILED DESCRIPTION OF THE TOPIC
2.1 OPERATION
2.1.1 Android Runtime
Android includes a set of core libraries that provides most of the functionality available in the core libraries of the Java programming language.
2.1.2 Linux Kernel
Android relies on Linux version 2.6 for core system services such as security, memory management, process management, network stack.
2.2 ARCHITECTURE
2.2.1 Linux Kernel
Android Architecture is based on Linux 2.6 kernel. It helps to manage security, memory management, process management, network stack and other important issues.
2.2.2 Libraries
In the next level there are a set of native libraries written in C/C++, which are responsible for stable performance of various components
2.2.3 Android Runtime
At the same level there is Android Runtime, where the main component Dalvik Virtual Machine is located. It has a core library written in Java programming language.
2.2.4 Application Framework
After that, there is Application Framework, written in Java language. It is a toolkit that all applications use, ones which come with mobile device like Contacts or SMS box, or applications written by Google and any Android developer.
2.2.5 Application Layer
At the top of Android Architecture we have all the applications, which are used by the final user. By installing different applications, the user can turn his mobile phone into the unique, optimized and smart mobile phone
CONCLUSION
Android is a mobile operating system initially developed by Android Inc. Android was bought by Google in 2005. Android is based upon a modified version of the Linux kernel. Google and other members of the Open Handset Alliance collaborated on Android's development and released it on may 2008.