Android is a Linux-based operating system for mobile devices such as smartphones and tablet computers. It is developed by the Open Handset Alliance led by Google.
Google purchased the initial developer of the software, Android Inc., in 2005. The unveiling of the Android distribution in 2007 was announced with the founding of the Open Handset Alliance, a consortium of 86 hardware, software, and telecommunication companies devoted to advancing open standards for mobile devices. Google releases the Android code as open-source, under the Apache License. TheAndroid Open Source Project (AOSP) is tasked with the maintenance and further development of Android.
Android was listed as the best-selling smartphone platform worldwide
Android, Inc. was founded in Palo Alto, California, United States in October, 2003 by Andy Rubin (co-founder ofDanger), Rich Miner (co-founder of Wildfire Communications, Inc.), Nick Sears (once VP at T-Mobile),and Chris White (headed design and interface development at WebTV)
Acquisition by Google
Google acquired Android Inc. on August 17, 2005, making Android Inc. a wholly owned subsidiary of Google Inc. Key employees of Android Inc., including Andy Rubin, Rich Miner and Chris White, stayed at the company after the acquisition. Not much was known about Android Inc. at the time of the acquisition, but many assumed that Google was planning to enter the mobile phone market with this move.
Open Handset Alliance
On November 5, 2007, the Open Handset Alliance, a consortium (A consortium is an association of two or more individuals, companies, organizations or governments (or any combination of these entities) with the objective of participating in a common activity or pooling their resources for achieving a common goal.) of several companies which include Broadcom Corporation, Google, HTC, Intel, LG, Marvell Technology Group, Motorola, Nvidia, Qualcomm, Samsung Electronics, Sprint Nextel, T-Mobile and Texas Instruments unveiled itself. The goal of the Open Handset Alliance is to develop open standards for mobile devices. On the same day, the Open Handset Alliance also unveiled their first product, Android, a mobile device platform built on the Linux kernel version 2.6
Linux Kernel :--
(The Linux kernel is the operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software.) version 2.6.
(in computing, the kernel is the main component of most computer operating systems; it is a bridge betweenapplications and the actual data processing done at the hardware level.)
On December 9, 2008, 14 new members joined, including ARM Holdings, Atheros Communications, Asustek Computer Inc, Garmin Ltd, Huawei Technologies,PacketVideo, Softbank, Sony Ericsson, Toshiba Corp, and Vodafone Group Plc
Android Open Source Project
The Android Open Source Project (AOSP) is led by Google, and is tasked with the maintenance and development of Android. According to the project "The goal of the Android Open Source Project is to create a successful real-world product that improves the mobile experience for end users." AOSP also maintains the Android Compatibility Program, defining an "Android compatible" device "as one that can run any application written by third-party developers using the AndroidSDK and NDK", to prevent incompatible Android implementations. The compatibility program is also optional and free of charge, with the Compatibility Test Suite also free and open-source.
Android consists of a kernel based on the Linux kernel, with middleware, libraries and APIs written in C and application software running on an application framework which includes Java-compatible libraries based on Apache Harmony. Android uses the Dalvik virtual machine with just-in-time compilation to run Dalvik dex-code (Dalvik Executable), which is usually translated from Java bytecode.
The main hardware platform for Android is the ARM architecture. There is support for x86 from the Android x86project, and Google TV uses a special x86 version of Android.
The platform is adaptable to larger, VGA, 2D graphics library, 3D graphics library based on OpenGL ES 2.0 specifications, and traditional smartphone layouts.
SQLite, a lightweight relational database, is used for data storage purposes.
Android supports connectivity technologies including GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE,NFC and WiMAX.
SMS and MMS are available forms of messaging, including threaded text messaging and now Android Cloud To Device Messaging (C2DM) is also a part of Android Push Messaging service.
Multiple language support
Android supports multiple languages.
While most Android applications are written in Java, there is no Java Virtual Machine in the platform and Java byte code is not executed. Java classes are compiled into Dalvik executables and run on Dalvik, a specialized virtual machine designed specifically for Android and optimized for battery-powered mobile devices with limited memory and CPU. J2ME support can be provided via third-party applications.
Android supports the following audio/video/still media formats: WebM, H.263, H.264 (in 3GP or MP4 container), MPEG-4 SP, AMR, AMR-WB (in 3GP container), AAC, HE-AAC (in MP4 or 3GP container), MP3, MIDI, Ogg Vorbis, FLAC, WAV, JPEG, PNG, GIF, BMP.
Streaming media support
RTP/RTSP streaming (3GPP PSS, ISMA), HTML progressive download (HTML5 <video> tag). Adobe Flash Streaming (RTMP) and HTTP Dynamic Streaming are supported by the Flash plugin. Apple HTTP Live Streaming is supported by RealPlayer for Android, and by the operating system in Android 3.0 (Honeycomb).
Additional hardware support
Android can use video/still cameras, touchscreens, GPS, accelerometers, gyroscopes, barometers, magnetometers, dedicated gaming controls, proximity andpressure sensors, thermometers, accelerated 2D bit blits (with hardware orientation, scaling, pixel format conversion) and accelerated 3D graphics.
Android has native support for multi-touch which was initially made available in handsets such as the HTC Hero. The feature was originally disabled at the kernel level (possibly to avoid infringing Apple's patents on touch-screen technology at the time). Google has since released an update for the Nexus One and theMotorola Droid which enables multi-touch natively.
Supports A2DP, AVRCP, sending files (OPP), accessing the phone book (PBAP), voice dialing and sending contacts between phones. Keyboard, mouse and joystick (HID) support is available in Android 3.1+, and in earlier versions through manufacturer customizations and third-party applications.
Android supports tethering, which allows a phone to be used as a wireless/wired Wi-Fi hotspot. Before Android 2.2 this was supported by third-party applications or manufacturer customizations.
FEATURES OF ANDROID OS:--
It is used to write applications for Android.
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.
It has an Web Kit as open source web browser.
It has a great Graphical Interface. ETC
• Integrated (web kit) browser
• 2D and 3D graphics APIs with HW
• Video and audio codecs
• Bluetooth, EDGE, 3G, and WiFi
• Camera, GPS, compass, and accelerometer
HARDWARE FEAUTURES SUPPORTED
Cellular networking : GSM, EDGE, 3G (hardware dependent)
LAN : Bluetooth, and Wi-Fi (hardware dependent)
Graphics Hardware Acceleration
Camera, GPS and Compass (hardware dependent)
Touch screen and accelerometer for motion sensing
Integrated browser based on the open source Web Kit engine
SQLite for relational data storage
Media support for common audio, video, and still image formats
(MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, GIF)
Dalvik Virtual Machine optimized for mobile devices
While Android is designed primarily for smartphones and tablets, the open and customizable nature of the operating system allows it to be used on other electronics, including laptops and netbooks, smartbooks, andebook readers. Further, Google intends to bring Android to televisions with Google TV, and the OS has seen applications on wristwatches,headphones, car CD and DVD players, smart glasses, refrigerators, vehicle satnav systems, home automation systems, cameras, games consoles, mirrors, digital cameras, portable media players andlandlines.
The first commercially available phone to run Android was the HTC Dream, released on 22 October 2008. In early 2010 Google collaborated with HTC to launch its flagship Android device, theNexus One. This was followed later in 2010 with the Samsung-made Nexus S and in 2011 with the Galaxy Nexus.
iOS and Android 2.3.3 'Gingerbread' may be set up to dual boot on a jailbroken iPhone or iPod Touch with the help ofOpeniBoot and iDroid.
In December 2011 it was announced the Pentagon has officially approved Android for use by its personnel
Applications are usually developed in the Java language using the Android Software Development Kit, but other development tools are available, including a Native Development Kit for applications or extensions in C or C++, Google App Inventor, a visual environment for novice programmers and various cross platform mobile web applications frameworks.
Android Software Development (SDK)
Android software development is the process by which new applications are created for the Android operating system. Applications are usually developed in the Java programming language using the Android Software Development Kit, but other development tools are available.
Google play ,Android Market
Google Play, formerly Android Market, is the online software store developed by Google for Android devices. An application program ("app") called "Market" is preinstalled on most Android devices and allows users to browse and download apps published by third-party developers, hosted on Android Market. As of October 2011 there were more than 300,000 apps available for Android, and the estimated number of applications downloaded from the Android Market as of December 2011 exceeded 10 billion. The operating system itself is installed on 130 million total devices
Android applications run in a sandbox, an isolated area of the operating system that does not have access to the rest of the system's resources, unless access permissions are granted by the user when the application is installed. Before installing an application, Play Store displays all required permissions. A game may need to enable vibration, for example, but should not need to read messages or access the phonebook. After reviewing these permissions, the user can decide whether to install the application.
Android Smartphone’s have the ability to report the location of Wi-Fi access points, encountered as phone users move around, to build databases containing the physical locations of hundreds of millions of such access points. These databases form electronic maps to locate Smartphone’s, allowing them to run apps like Foursquare, Latitude, Places, and to deliver location-based ads.
Third party monitoring software such as TaintDroid, an academic research-funded project, can, in some cases, detect when personal information is being sent from applications to remote servers.
In March 2012 it was revealed that Android Apps can copy photos without explicit user permission, Google responded they "originally designed the Android photos file system similar to those of other computing platforms like Windows and Mac OS. [...] we're taking another look at this and considering adding a permission for apps to access images. We've always had policies in place to remove any apps on Android Market that improperly access your data
The Android logo was designed along with the Droid font family made by Ascender Corporation.
Android Green is the color of the Android Robot that represents the Android operating system. The print color is PMS 376C and the RGB color value in hexadecimal is #A4C639, as specified by the Android Brand Guidelines. The custom typeface of Android is called Norad (cf. NORAD). It is only used in the text logo.
• Android is a software platform and operating system for mobile devices based on the Linux operating system.
• It is developed by Google and the Open Handset Alliance.
• It allows developers to write managed code in a Java-like language that utilizes Google-developed Java libraries, but does not support programs developed in native code.
• An open platform for developers, users & industry.
• Android is open source/free software
Android allows you to access core mobile device functionality through standard API calls.
2) All applications are equal:-
Android does not differentiate between the phone's basic and third-party applications -- even the dialer or home screen can be replaced.
3) Breaking down boundaries:-
Combine information from the web with data on the phone -- such as contacts or geographic location -- to create new user experiences.
4) Fast and easy development:-
The SDK contains what you need to build and run Android applications, including a true device emulator and advanced debugging tools.
Making source code available to everyone inevitably invites the attention of black hat hackers.
2) Open Source:-
A disadvantage of open-source development is that anyone can scrutinize the source code to find vulnerabilities and write exploits.
Platform doesn't run on an encrypted file system and has a vulnerable log-in.
The dependence on hardware and carrier partners puts the final product out of their control.
WHAT MAKES ANDROID SPECIAL
OPEN SOURCE –DEVELOPER CAN CUSTOMIZE THE PLATFORM
BUILT IN COMPONENTS CAN BE IMPROVED
BUILT IN SERVICES LIKE GPS,SQL,DATABASE,BROWSER AND MAPS
MANAGEMENT OF PROCESS LIFE CYCLE
HIGH QUALITY GRAPHICS AND SOUND
PORTABILITY ACROSS CURRENT AND FUTURE HARDWARE
Truly open, free development platform
Component-based architecture and Reusable, replaceable modules
Multi-layer isolation of programs
High quality graphics and sound and Portability across hardware
Java programs executed by Davlik virtual machine and Support by multiple large organizations
The Android SDK includes a variety of custom tools that help you develop mobile applications on the Android platform.Three of the most significant tools are:
1. Android Emulator -A virtual mobile device that runs on our computer -use to design, debug, and test our applications in an actual Android run-time environment
1. Android Development Tools Plugin -for the Eclipse IDE - adds powerful extensions to the Eclipse integrated environment
1. Dalvik Debug Monitor Service (DDMS) -Integrated with Dalvik -this tool let us manage processes on an emulator and assists in debugging
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