CHAPTER - 1

1.1 What is Android?

Android is a stack of software for mobile devices that arc an Operating System, Middleware and Key
Applications.

Android is a Linux-based operating system which is designed for touchscreen mobile devices like
smartphones and tablet computers.
It is an open source technology that allows the software to be freely modified and distributed by
device manufacturers, wireless carriers and developers.
Android was unveiled during 2007 along with the founding of the Open Handset Alliance.

1.2 What is "Open Handset Alliance"?

Open Handset Alliance (0HA) was formed in November 2007.The 0HA is the group that is in charge
of the Android smartphones operating system.
It was created by Google. The Open Handset Alliance (0HA) is a business alliance that consists of 47
companies for developing open standard platform for mobile devices.
The members of OHA include handset manufactures, chip makers, commercialization companies,
software companies, and mobile operators.

1
1.3 Android Ecosystem

If we want to learn about Android and develop Android applications, it is very important for us to
understand the entire ecosystem of Android and the stakeholders of this ecosystem.

The stakeholders are the consumers that own Android devices. But there are others as well:
• Google: It develops Android.
• OEMs (Original Equipment Manufacturers): They manufacture the hardware, and as well the
custom application components?
• Application Development Companies: They are the major contributors to the ecosystem and
employ Android developers, and also contract out the product development to services companies.
• Freelance Android developers: Developers have the skill-set to contribute to the ecosystem for
Android development, they are who create their own applications, and publish them on Google
playstore. Freelancers can also generate money by developing applications for product companies.

1.4 Why android???

1. Browser:

The Android browser is one of the best browsers on the mobile market. It generally
loads pages faster than Safari or any other browser, has flash support and simply does
everything a browser should do.

e.g., iPhone has safari browser.

2. Desktop:

The Android phone adds widgets to the desktop. The purpose for the widget

e.g.

The Facebook widget allows you to update your facebook desktop.

2
 3. Connectivity:
On one page/desktop you could be able to have four connecting device tool button.

+ Turn on/off Bluetooth + Turn on/off WiFi

These buttons let you switch on/off instantly which will help you to conserve battery
life.

4. Multi-Notification:
Android phones have multi-notification system. With android the app have access to the
notification system and call all report.
5. Endless Personalization:
The Android cell phone allows client to configuration their mobile to look
and behave exactly like they want.

6. Market: Android has an android market. The Android apps are free and work as well.

7. Google Integration: The Android has inbuilt google support. e.g., Google map, gmail etc.

8. Open Source: The code of android OS as well as the apps is available.

9. Open to Carrier: If you know java then you are open to android world.

10. Future: The future mobile phones are basically going to be smart phones.

Android Versions

3
1.7. Features of Android:

Android is a powerful operating system competing with Apple 4GS and supports great features. Few of
them are listed below −

Sr.No Feature & Description

1 Beautiful UI
Android OS basic screen provides a beautiful and intuitive user interface.

2 Connectivity
GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE, NFC and WiMAX.

3 Storage

4
 SQLite, a lightweight relational database, is used for data storage purposes.

4 Media support
H.263, H.264, MPEG-4 SP, AMR, AMR-WB, AAC, HE-AAC, AAC 5.1, MP3, MIDI, Ogg
Vorbis, WAV, JPEG, PNG, GIF, and BMP.

5 Messaging
SMS and MMS

6 Web browser
Based on the open-source WebKit layout engine, coupled with Chrome's V8 JavaScript
engine supporting HTML5 and CSS3.

7 Multi-touch
Android has native support for multi-touch which was initially made available in handsets
such as the HTC Hero.

8 Multi-tasking
User can jump from one task to another and same time various application can run
simultaneously.

9 Resizable widgets
Widgets are resizable, so users can expand them to show more content or shrink them to
save space.

10 Multi-Language
Supports single direction and bi-directional text.

11 GCM
Google Cloud Messaging (GCM) is a service that lets developers send short message
data to their users on Android devices, without needing a proprietary sync solution.

12 Wi-Fi Direct
A technology that lets apps discover and pair directly, over a high-bandwidth peer-to-
peer connection.

13 Android Beam
A popular NFC-based technology that lets users instantly share, just by touching two
NFC-enabled phones together.

1. Open Source 2. Storage 3. Media support 4. Streaming media support

Android architecture is a software stack of components to support a mobile device needs. Android
software stack contains a Linux Kernel, collection of c/c++ libraries which is exposed through an
application framework services, runtime and application.

Following are main components of android architecture those are

1. Applications

5
 2. Android Framework
3. Android Runtime
4. Platform Libraries
5. Linux Kernel

In these components Linux Kernel is the main component in android to provide its operating
system functions to mobile and Dalvik Virutal Machine (DVM) which is responsible for running a
mobile application.

Following is the pictorial representation of android architecture with different components.

Applications

6
The top layer of android architecture is Applications. The native and third party applications like
contacts, email, music, gallery, clock, games, etc. whatever we will built those will be installed on this
layer only.

The application layer runs within the Android run time using the classes and services made available
from the application framework.

Application Framework
The Application Framework provides the classes used to create an Android applications. It also
provides a generic abstraction for hardware access and manages the user interface and application
resources. It basically provides the services through which we can create the particular class and
make that class helpful for the Applications creation.

The application framework includes services like telephony service, location services, notification
manager, NFC service, view system, etc. which we can use for application development as per our
requirements.

Android Runtime
Android Runtime environment is an important part of Android rather than an internal part and it
contains a components like core libraries and the Dalvik virtual machine. The Android run time is
the engine that powers our applications along with the libraries and it forms the basis for the
application framework.

Dalvik Virtual Machine (DVM) is a register-based virtual machine like Java Virtual Machine (JVM). It
is specially designed and optimized for android to ensure that a device can run multiple instances
efficiently. It relies on the Linux kernel for threading and low-level memory management.

The core libraries in android runtime will enable us to implement an android applications using
standard JAVA programming language.

Platform Libraries
The Platform Libraries includes various C/C++ core libraries and Java based libraries such as SSL,
libc, Graphics, SQLite, Webkit, Media, Surface Manger, OpenGL etc. to provide a support for android
development.

Following are the summary details of some core android libraries available for android development.

 Media library for playing and recording an audio and video formats
 The Surface manager library to provide a display management
 SGL and OpenGL Graphics libraries for 2D and 3D graphics
 SQLite is for database support and FreeType for font support

7
  Web-Kit for web browser support and SSL for Internet security.

Linux Kernel
Linux Kernel is a bottom layer and heart of the android architecture. It manage all the drivers such as
display drivers, camera drivers, Bluetooth drivers, audio drivers, memory drivers, etc. which are mainly
required for the android device during the runtime.

The Linux Kernel will provides an abstraction layer between the device hardware and the remainder
of the stack. It is responsible for memory management, power management, device management,
resource access, etc.