Project Report

Project ReportAndroid Operating System & Applications

Submitted to:Submitted by:Mrs. Rajandeep KaurNavjot Singh (41 ME-14)Deepak Kumar (43-ME-14)Mandeep Mahi (44-ME-14)Rahul Sadana (45-ME-14)

ACKNOWLEDGMENT

The satisfaction that accompanies that the successful completion of any task would be incomplete without the mention of people whose ceaseless cooperation made it possible, whose constant guidance and encouragement crown all efforts with success.We are grateful to our project guide Mrs. Rajandeep Kaur for the guidance, inspiration and constructive suggestions that helpful us in the preparation of this project.We also thank our colleagues who have helped in successful completion of the project.

INDEXINTRODUCTION4HISTORY5Open Handset Alliance6Licensing6Version History7FEATURES12HARDWARE RUNNING ANDROID15SOFTWARE DEVELOPMENT15Software Development Kit15Android Market17App Inventor for Android17Android Developer Challenge18Google Applications18Third Party Applications18Mobile Gaming19Native Code19Community-Based Firmware20SECURITY ISSUES21MARKETING22Logos22Typeface22Market Share22DETAILED DESCRIPTION OF THE TOPIC24Operation24Architecture25Developing Applications28LINUX COMPATIBILITY39CLAIMED INFRINGEMENT OF COPYRIGHTS AND PATENTS40CONCLUSION AND FUTURE SCOPE41QUESTIONNAIRE42BIBLIOGRAPHY43

INTRODUCTIONAndroid is an open-source software stack for mobile devices that includes an operating system, middleware and key applications. Google Inc. purchased the initial developer of the software, Android Inc., in 2005. Android's mobile operating system 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 release. The Android Open Source Project (AOSP) is tasked with the maintenance and further development of Android.Canalys reported that in Q4 2010 the Android operating system was the world's best-selling smartphone platform, dethroning Nokia's Symbian from the 10-year top position. Jumping from 23.5 percent, Android now represents 31.2 percent of the U.S smartphone market. According to Gartner, Symbian is still slightly ahead on sales if some legacy non-Nokia Symbian smartphones are included in the Q4 2010 figures.Android has a large community of developers writing application programs ("apps") that extend the functionality of the devices. There are currently over 150,000 apps available for Android. Android Market is the online app store run by Google, though apps can also be downloaded from third-party sites. Developers write primarily in the Java language, controlling the device via Google-developed Java libraries.The unveiling of the Android distribution on 5 November 2007 was announced with the founding of the Open Handset Alliance, a consortium of 80 hardware, software, and telecom companies devoted to advancing open standards for mobile devices. Google released most of the Android code under the Apache License, a free software and open source license.The Android open-source software stack consists of Java applications running on a Java-based, object-oriented application framework on top of Java core libraries running on a Dalvik virtual machine featuring JIT compilation. Libraries written in C include the surface manager, OpenCore media framework, SQLite relational database management system, OpenGL ES 2.0 3D graphics API, WebKit layout engine, SGL graphics engine, SSL, and Bionic libc. The Android operating system consists of 12million lines of code including 3million lines of XML, 2.8million lines of C, 2.1million lines of Java, and 1.75million lines of C++.

HISTORYAndroid Inc. founded in 2003Android, Inc. was founded in Palo Alto, California, United States in October, 2003 by Andy Rubin, Rich Miner, et al. to develop, in Rubin's words "...smarter mobile devices that are more aware of its owner's location and preferences." Key employees involved in the founding of Android Inc. include Andy Rubin, also the co-founder of Danger Inc., Andy McFadden, who worked with Rubin at WebTV, and Chris White, who led the design and interface of WebTV. Other crucial employees includes Richard Miner, a co-founder of Wildfire Communications, Inc. and former vice-president of Technology and innovation at Orange, and all those of whom brought considerable wireless industry experience to the company. Despite the obvious past accomplishments of the founders and early employees, Android Inc. operated secretively, admitting only that it was working on software for mobile phones.Android Inc. acquired by GoogleGoogle acquired Android Inc. in August, 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 so many assumed that Google was planning to enter the mobile phone market with this move.Development acceleratesAt Google, the team led by Rubin developed a mobile device platform powered by the Linux kernel. Google marketed the platform to handset makers and carriers on the premise of providing a flexible, upgradable system. Google had lined up a series of hardware component and software partners and signaled to carriers that it was open to various degrees of cooperation on their part.Speculation about Google's intention to enter the mobile communications market continued to build through December 2006. Reports from the BBC and The Wall Street Journal noted that Google wanted its search and applications on mobile phones and it was working hard to deliver that. Print and online media outlets soon reported rumors that Google was developing a Google-branded handset. Some speculated that as Google was defining technical specifications, it was showing prototypes to cell phone manufacturers and network operators.In September 2007, InformationWeek covered an Evalueserve study reporting that Google had filed several patent applications in the area of mobile telephony.Open Handset AllianceMain article: Open Handset Alliance"Today's announcement is more ambitious than any single 'Google Phone' that the press has been speculating about over the past few weeks. Our vision is that the powerful platform we're unveiling will power thousands of different phone models." Eric Schmidt, former Google Chairman/CEO

On the November 5, 2007 the Open Handset Alliance, a group 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.On December 9, 2008, 14 new members joined, including ARM Holdings, Atheros Communications, Asustek Computer Inc, Garmin Ltd, PacketVideo, Softbank, Sony Ericsson, Toshiba Corp, and Vodafone Group Plc.LicensingWith the exception of brief update periods, Android has been available under a free software/open source license since 21 October 2008. Google published the entire source code (including network and telephony stacks) under an Apache License. Google also keeps the reviewed issues list publicly open for anyone to see and comment.Even though the software is open-source, device manufacturers can not use Google's Android trademark unless Google certifies that the device complies with their Compatibility Definition Document (CDD). Devices must also meet this definition to be eligible to license Google's closed-source applications, including Android Market.In September 2010, Skyhook Wireless filed a lawsuit against Google in which they alleged that Google had used the compatibility document to block Skyhook's mobile positioning service (XPS) from Motorola's Android mobile devices. In December 2010 a judge denied Skyhook's motion for preliminary injunction, saying that Google had not closed off the possibility of accepting a revised version of Skyhook's XPS service, and that Motorola had terminated their contract with Skyhook because Skyhook wanted to disable Google's location data collection functions on Motorola's devices, which would have violated Motorola's obligations to Google and its carriers.Version HistoryAndroid has seen a number of updates since its original release. These updates to the base operating system typically focus on fixing bugs as well as adding new features. Generally each new version of the Android operating system is developed under a code name based on a dessert item.The most recent released versions of Android are:Android 1.0 Launched on the HTC Dream/T-Mobile G1 in 2008 The primary new feature launched with Android 1.0 was the notification toolbar, which users could access by pulling down the menu to preview all notifications. Google Sync was also introduced in this version, which synced Google account calendar and contact information from the users phone. The multiple Home screen format was also introduced, which has basically remained in every version of Android to follow this release. Widgets were also added, which gave users easy access to information with a single tap of the finger.

Android 1.1 Launched in 2009 The second release was Android 1.1, which was primarily designed for refinements in Android 1.0. The main purpose of the release was to fix a number of bugs that were present in Android 1.0, with a few minor features and adjustments added. Aside from these updates, most of the other functions remained the same.Android 1.5 (Cupcake) Launched in April of 2009

This operating system initiated the following versions of Android named after a sweet confection.In this release, the camera was introduced with the capability to upload videos to Google Picasa and video sites, such as YouTube. Additionally, this version of the Android operating system contained the first copy and paste function in the web browser.

Android 1.6 (Donut) Launched in September of 2009

This version of the Android introduced new support for higher resolution screen displays.The design of the operating system was simplified and included an updated Google search function. This allowed users to easily search the device for apps, contacts, and Internet data. It was in the Android 1.6 operating system that the Gesture Builder development application was also added.Android 2.0/2.1 (clair) Launched in October of 2009

The release of Android 2.0/2.1 introduced improved typing functionality on the Motorola Droid with auto-correction. This was accomplished by offering a significant improvement in the keyboard functionality.Support for HTML5 was also first introduced in 2.1 along with additional camera functions, a new interface for the browser, and Bluetooth capability.Android 2.2 (FroYo) Launched in May of 2010

The release of this version of the Android marked the inception of the Nexus smartphones, starting off with HTC Nexus One.Additional features were added to the camera functionality. Other capabilities included tethering via USB, new mobile hotspot functionality, support for Adobe Flash, and the ability to use Android Market, which is now Google Play, to automatically update apps. The User Interface was also upgraded to increase device performance.

Android 2.3 (Gingerbread) Launched in December of 2010

The Android 2.3 operating system was launched on the second Nexus smartphone which was produced by Samsung, Samsung Nexus S.It was at this point that a few primary features were introduced such as support for Near Field Communications (NFC), improvements in the User Interface which enhanced device performance, Internet calling capability, and an enhanced keyboard for faster typing input. 2.3 also provided for enhanced screen resolution, as well as support for a front facing camera.

Android 3.0 (Honeycomb) Launched in February of 2011

This version of the Android operating system marked the first operating system designed for a tablet. It was this operating system that first introduced on-screen buttons for tap functionality. The apps were also redesigned for better viewing on a larger screen, along with the first web browser with multiple tab capability.Multitasking was also improved, which made it no longer necessary to switch apps. Instead, users could simply bring apps currently open to the front of the screen with a single tap of a button.In the final update of 3.0, support for Google Wallet was added in addition to a multi-core processor, which increased performance and device efficiency.

Android 4.0 (Ice Cream Sandwich) Launched in October 2011

Android 4.0 was released with significant improvements in the interface; the main one being the removal of hardware buttons, replaced with onscreen buttons to continue what Android 3.0 started. The Android music player was also replaced with a new Google Music app.Other new features introduced in this version of Android included management for apps running in the background, swipe to dismiss notifications, Android Beam which is a secure platform for sharing content, the new Roboto typeface, WiFi Direct, and the capability to rearrange folders.

Android 4.1, 4.2, 4.3 (Jelly Bean) Launched in June 2012, November 2012, July 2013

This version of the Android operating system offered a brand new interface, which provided smoother and faster performance. Google Voice search was also improved in this version with enhanced Accessibility options and support for Braille input.The Android Beam sharing feature underwent an upgrade to include the option to easily transfer videos and photos. Additionally, Google Now was introduced along with actionable notification improvements to the Notification Center. Jelly Bean also offered new security enhancements such, as Smart App updates and App encryption.

Android 4.4 (Kit Kat) Launched in October 2013

One of the most important updates to Android 4.4 Kit Kat is streamlined performance, named Project Svelte. Svelte is Googles attempt to lower the system requirements as opposed to increasing them. Typically, when users go from an older version of an OS to a newer one, the system requirements usually increase.Instead, the newest version of Android runs smoother, faster, more efficient, and more responsively on devices with as little as one half GB of RAM.Also, with the new release of 4.4 is the introduction of new APIs, in an effort to help developers make great apps that will run smoother and more responsively on more devices, especially on the older devices with lower specs.There is also a new built-in setting called Process Stats. In past versions of Android, users could see exactly how much storage each app was using on their device. Process Stats is an app that functions in a similar fashion by allowing users to see how much RAM the individual applications are using, which gives users an accurate read on whether or not they will be needing more RAM.

The upcoming version of Android is:Android 5.0 "Lollipop"is a version of theAndroidmobile operating systemdeveloped byGoogle. Unveiled on June 25, 2014, the operating system will be first made available in November 2014 for selected devices that run distributions of Android that are serviced by Google, includingNexusandGoogle Play editiondevices.

FEATURES1. 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. It is also supported by the Android core libraries. From the point of security, the framework is based on UNIX file system permissions that assure applications have only those abilities that mobile phone owner gave them at install time. 2. Dalvik Virtual MachineIt 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 is also tuned to the CPU attributes. The Dalvik VM creates a special file format (.DEX) that is created through build time post processing. Conversion between Java classes and .DEX format is done by included dx tool.

3. Integrated BrowserGoogle 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, such as external CSS or external JavaScript and after a while renders again with all resources downloaded to the device. Frame flattening converts founded frames into single one and loads into the browser. These features increase speed and usability browsing the internet via mobile phone. 4. Optimized GraphicsAs 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, which come on Linux version. At this moment, the shooting legendary 3D game Doom was presented using Android on the mobile phone. 5. SQLiteExtremely small (~500kb) relational database management system, which is integrated in Android. It is based on function calls and single file, where all definitions, tables and data are stored. This simple design is more than suitable for a platform such as Android. 6. Handset Layouts The platform is adaptable to both larger, VGA, 2D graphics library, 3D graphics library based on OpenGL ES 1.0 specifications, traditional smart phone layouts. An underlying 2D graphics engine is also included. Surface Manager manages access to the display subsystem and seamlessly composites 2D and 3D graphic layers from multiple applications7. Data Storage SQLite is used for structured data storage .SQLite is a powerful and lightweight relational database engine available to all applications.8. Connectivity Android supports a wide variety of connectivity technologies including GSM, CDMA, Bluetooth, EDGE, EVDO, 3G and Wi-Fi.9. Messaging SMS, MMS, and XMPP are available forms of messaging including threaded text messaging.10. Web Browser The web browser available in Android is based on the open-source WebKit application framework. It includes LibWebCore which is a modern web browser engine which powers both the Android browser and an embeddable web view.11. Java Virtual Machine Software written in Java can be compiled into Dalvik bytecodes and executed in the Dalvik virtual machine, which is a specialized VM implementation designed for mobile device use, although not technically a standard Java Virtual Machine. 12. Media Support Android will support advanced audio/video/still media formats such as MPEG-4, H.264, MP3, and AAC, AMR, JPEG, PNG, GIF. 13. Additional Hardware Support Android is fully capable of utilizing video/still cameras, touchscreens, GPS, compasses, accelerometers, and accelerated 3D graphics. 14. Development Environment Includes a device emulator, tools for debugging, memory and performance profiling, a plugin for the Eclipse IDE. There are a number of hardware dependent features, for instance, a huge media and connections support, GPS, improved support for Camera and simply GSM telephony. A great work was done for the developers to start work with Android using device emulator, tools for debugging and plugin for Eclipse IDE.HARDWARE RUNNING ANDROIDThe Android OS can be used as an operating system for cellphones, netbooks and tablets, including the Dell Streak, Samsung Galaxy Tab, TV and other devices. The first commercially available phone to run the Android operating system was the HTC Dream, released on 22 October 2008. In early 2010 Google collaborated with HTC to launch its flagship Android device, the Nexus One. This was followed later in 2010 with the Samsung-made Nexus S.iOS and Android 2.2.1 Froyo may be setup to dual boot on a jailbroken iPhone or iPod Touch with the help of iBoot and iDroid.SOFTWARE DEVELOPMENTThe early feedback on developing applications for the Android platform was mixed. Issues cited include bugs, lack of documentation, inadequate QA infrastructure, and no public issue-tracking system. (Google announced an issue tracker on 18 January 2008.) In December 2007, MergeLab mobile startup founder Adam MacBeth stated, "Functionality is not there, is poorly documented or just doesn't work... It's clearly not ready for prime time." Despite this, Android-targeted applications began to appear the week after the platform was announced. The first publicly available application was the Snake game. The Android Dev Phone is a SIM-unlocked and hardware-unlocked device that is designed for advanced developers. While developers can use regular consumer devices purchased at retail to test and use their applications, some developers may choose not to use a retail device, preferring an unlocked or no-contract device.Software Development KitThe Android software development kit (SDK) includes a comprehensive set of development tools. These include a debugger, libraries, a handset emulator (based on QEMU), documentation, sample code, and tutorials. Currently supported development platforms include computers running Linux (any modern desktop Linux distribution), Mac OS X 10.4.9 or later, Windows XP or later. The officially supported integrated development environment (IDE) is Eclipse (currently 3.4, 3.5 or 3.6) using the Android Development Tools (ADT) Plugin, though developers may use any text editor to edit Java and XML files then use command line tools (Java Development Kit and Apache Ant are required) to create, build and debug Android applications as well as control attached Android devices (e.g., triggering a reboot, installing software package(s) remotely).A preview release of the Android SDK was released on 12 November 2007. On 15 July 2008, the Android Developer Challenge Team accidentally sent an email to all entrants in the Android Developer Challenge announcing that a new release of the SDK was available in a "private" download area. The email was intended for winners of the first round of the Android Developer Challenge. The revelation that Google was supplying new SDK releases to some developers and not others (and keeping this arrangement private) led to widely reported frustration within the Android developer community at the time.On 18 August 2008 the Android 0.9 SDK beta was released. This release provided an updated and extended API, improved development tools and an updated design for the home screen. Detailed instructions for upgrading are available to those already working with an earlier release. On 23 September 2008 the Android 1.0 SDK (Release 1) was released. According to the release notes, it included "mainly bug fixes, although some smaller features were added." It also included several API changes from the 0.9 version. Multiple versions have been released since.Enhancements to Android's SDK go hand in hand with the overall Android platform development. The SDK also supports older versions of the Android platform in case developers wish to target their applications at older devices. Development tools are downloadable components, so after one has downloaded the latest version and platform, older platforms and tools can also be downloaded for compatibility testing.Android applications are packaged in .apk format and stored under /data/app folder on the Android OS (the folder is accessible to root user only for security reasons). APK package contains .dex files (compiled byte code files called Dalvik executable), resource files, etc.

Android MarketAndroid 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 December 2010[update] there were about 200,000 games, applications and widgets available on the Android Market, with an estimated 2.5 billion total downloads.Only devices that comply with Google's compatibility requirements are allowed to preinstall Google's closed-source Android Market app and access the Market. The Market filters the list of applications presented by the Market app to those that are compatible with the user's device, and developers may restrict their applications to particular carriers or countries for business reasons.Google announced the Android Market on 28 August 2008, and it was available to users on 22 October 2008. Support for paid applications was available from 13 February 2009 for US and UK developers, with additional support from 29 countries on 30 September 2010. In February 2011, the Android Market was made fully accessible on the web, allowing users to browse and pick up applications using their PCs, send them to their mobile phone and make comments on them. All this functionality was previously accessible only from mobile phone devices.Users can install apps directly using APK files, or from alternative app markets. Unlike Apple, Google allows independent app stores to operate for Android.App Inventor for AndroidOn 12 July 2010 Google announced the availability of App Inventor for Android, a Web-based visual development environment for novice programmers, based on MIT's Open Blocks Java library and providing access to Android devices' GPS, accelerometer and orientation data, phone functions, text messaging, speech-to-text conversion, contact data, persistent storage, and Web services, initially including Amazon and Twitter. "We could only have done this because Androids architecture is so open," said the project director, MIT's Hal Abelson. Under development for over a year, the block-editing tool has been taught to non-majors in computer science at Harvard, MIT, Wellesley, and the University of San Francisco, where Professor David Wolber developed an introductory computer science course and tutorial book for non-computer science students based on App Inventor for Android.Android Developer ChallengeThe Android Developer Challenge was a competition for the most innovative application for Android. Google offered prizes totaling 10 million US dollars, distributed between ADC I and ADC II. ADC I accepted submissions from 2 January to 14 April 2008. The 50 most promising entries, announced on 12 May 2008, each received a $25,000 award to fund further development. It ended in early September with the announcement of ten teams that received $275,000 each, and ten teams that received $100,000 each. ADC II was announced on 27 May 2009. The first round of the ADC II closed on 6 October 2009. The first-round winners of ADC II comprising the top 200 applications were announced on 5 November 2009. Voting for the second round also opened on the same day and ended on November 25. Google announced the top winners of ADC II on November 30, with SweetDreams, What the Doodle!? and WaveSecure being nominated the overall winners of the challenge.Google ApplicationsGoogle has also participated in the Android Market by offering several applications for its services. These applications include Google Voice for the Google Voice service, Sky Map for watching stars, Finance for their finance service, Maps Editor for their MyMaps service, Places Directory for their Local Search, Google Goggles that searches by image, Gesture Search for using finger-written letters and numbers to search the contents of the phone, Google Translate, Google Shopper, Listen for podcasts and My Tracks, a jogging application.In August 2010, Google launched "Voice Actions for Android," which allows users to search, write messages, and initiate calls by voice.Third Party ApplicationsWith the growing number of Android handsets, there has also been an increased interest by third party developers to port their applications to the Android operating system.As of December 2010, the Android Marketplace had over 200,000 applications, with over 1 billion downloads. This is up from 70,000 in July 2010.Obstacles to development include the fact that Android does not use established Java standards, i.e. Java SE and ME. This prevents compatibility among Java applications written for those platforms and those for the Android platform. Android only reuses the Java language syntax, but does not provide the full-class libraries and APIs bundled with Java SE or ME. However, there are multiple tools in the market from companies such as Myriad Group and UpOnTek that provide J2ME to Android conversion services.Developers have reported that it is difficult to maintain applications on multiple versions of Android, owing to compatibility issues between versions 1.5 and 1.6, especially the different resolution ratios in use among various Android phones. Such problems were pointedly brought into focus as they were encountered during the ADC2 contest. Further, the rapid growth in the number of Android-based phone models with differing hardware capabilities also makes it difficult to develop applications that work on all Android-based phones. As of August 2010, 83% of Android phones run the 2.x versions, and 17% still run the 1.5 and 1.6 versions.Mobile GamingAndroid had a huge showing at the 2011 Mobile World Congress in regards to smartphone gaming, with many well established game developers showcasing Android games. The trend in mobile gaming on smartphone devices is predicted to shrink the game specialist device market, affecting devices such as the upcoming Next Generation Portable.Native CodeLibraries written in C and other languages can be compiled to ARM native code and installed using the Android Native Development Kit. Native classes can be called from Java code running under the Dalvik VM using the System.loadLibrary call, which is part of the standard Android Java classes.Complete applications can be compiled and installed using traditional development tools. The ADB debugger gives a root shell under the Android Emulator which allows native ARM code to be uploaded and executed. ARM code can be compiled using GCC on a standard PC. Running native code is complicated by the fact that Android uses a non-standard C library (libc, known as Bionic). The underlying graphics device is available as a framebuffer at /dev/graphics/fb0. The graphics library that Android uses to arbitrate and control access to this device is called the Skia Graphics Library (SGL), and it has been released under an open source license. Skia has backends for both win32 and UNIX, allowing the development of cross-platform applications, and it is the graphics engine underlying the Google Chrome web browser.Community-Based FirmwareThere is a community of open-source enthusiasts that build and share Android-based firmware with a number of customizations and additional features, such as FLAC lossless audio support and the ability to store downloaded applications on the microSD card. This usually involves rooting the device. Rooting allows users root access to the operating system, enabling full control of the phone. In order to use custom firmwares the device's bootloader must be unlocked. Rooting alone does not allow the flashing of custom firmware. Modified firmwares allow users of older phones to use applications available only on newer releases.Those firmware packages are updated frequently, incorporate elements of Android functionality that haven't yet been officially released within a carrier-sanctioned firmware, and tend to have fewer limitations. CyanogenMod and VillainROM are two examples of such firmware.On 24 September 2009, Google issued a cease and desist letter to the modder Cyanogen, citing issues with the re-distribution of Google's closed-source applications within the custom firmware. Even though most of Android OS is open source, phones come packaged with closed-source Google applications for functionality such as the application store and GPS navigation. Google has asserted that these applications can only be provided through approved distribution channels by licensed distributors. Cyanogen has complied with Google's wishes and is continuing to distribute this mod without the proprietary software. He has provided a method to back up licensed Google applications during the mod's install process and restore them when it is complete.

SECURITY ISSUESIn March 2011, Google pulled 58 malicious apps from the Android Market, but not before the 58 apps were downloaded to around 260,000 devices. These apps were malicious applications in the Android Market which contained trojans hidden in pirated versions of legitimate apps. The malware (called DroidDream) exploited a bug which was present in versions of Android older than 2.2.2. Android device manufacturers and carriers work in tandem to distribute Android based updates and had not uniformly issued patches to their customers for the DroidDream exploit, leaving users vulnerable. Google said the exploit allowed the apps to gather device specific information, as well as personal information. Within days, Google remotely wiped the apps from infected users and rolled out an update that would negate the exploits that allowed the apps to view information. They also announced that they would be resolving the issue to ensure that events like this did not occur again. Security firms such as AVG and Symantec have released antivirus software for Android devices.In August 2010, an SMS Trojan called Trojan-SMS.AndroidOS.FakePlayer.a infected a number of mobile devices, according to security firm Kaspersky Lab. Disguised as a harmless media player application, the trojan, once installed sends out SMS text messages without the users knowledge or consent. According to Denis Maslennikov, Senior Malware Researcher at Kaspersky Lab, there's not an exact number of infected devices available at present, but the outbreak is currently regional. For now, only Russian Android users can actually lose money after installing the Trojan, but anyone can be infected. Android users were advised not to use the Android web browser until Google issues a security patch. The Android Security Team responded and developed a fix on February 5th and patched Open Source Android two days later.

MARKETINGLogosThe Android logo was designed 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.

Android logoTypefaceThe custom typeface of Android is called Norad, only used in the text logo.Market ShareResearch company Canalys estimated in Q2 2009 that Android had a 2.8% share of worldwide smartphone shipments. By Q4 2010 this had grown to 33% of the market, becoming the top-selling smartphone platform. This estimate includes the Tapas and OMS variants of Android.In February 2010 ComScore said the Android platform had 9.0% of the U.S. smartphone market, as measured by current mobile subscribers. This figure was up from an earlier estimate of 5.2% in November 2009. By the end of Q3 2010 Android's U.S. market share had grown to 21.4 percent.In May 2010, Android's first quarter U.S. sales surpassed that of the rival iPhone platform. According to a report by the NPD group, Android achieved 25% smartphone sales in the US market, up 8% from the December quarter. In the second quarter, Apple's iOS was up by 11%, indicating that Android is taking market share mainly from RIM, and still has to compete with heavy consumer demand for new competitor offerings. Furthermore, analysts pointed to advantages that Android has as a multi-channel, multi-carrier OS, which allowed it to duplicate the quick success of Microsoft's Windows Mobile.In early October 2010, Google added 20 countries to its list of approved submitters. By mid-October, purchasing apps will be available in a total of 32 countries. For a complete list of countries that are allowed to sell apps and those able to buy them see Android Market.As of December 2010[update] Google said over 300,000 Android phones were being activated daily, up from 100,000 per day in May 2010.In February 2011, during the 2011 Mobile World Congress, Eric Schmidt announced that Android has reached 350,000 activations per day.Usage shareData collected during two weeks ending on March 15, 2011

Data collected during two weeks ending on March 15, 2011

Platform API LevelDistribution

Android 3.0 (Honeycomb)110.2%

Android 2.3.3 (Gingerbread)101.0%

Android 2.3 (Gingerbread)90.7%

Android 2.2 (Froyo)861.3%

Android 2.1 (Eclair)729.0%

Android 1.6 (Donut)44.8%

Android 1.5 (Cupcake)33.0%

DETAILED DESCRIPTION OF THE TOPICOperation1. Android RuntimeAndroid includes a set of core libraries that provides most of the functionality available in the core libraries of the Java programming language.Every Android application runs in its own process, with its own instance of the Dalvik virtual machine. Dalvik has been written so that a device can run multiple VMs efficiently.The Dalvik VM executes files in the Dalvik Executable (.dex) format which is optimized for minimal memory footprint. The VM is register-based, and runs classes compiled by a Java language compiler that have been transformed into the .dex format by the included "dx" tool.The Dalvik VM relies on the Linux kernel for underlying functionality such as threading and low-level memory management.2. Linux KernelAndroid relies on Linux version 2.6 for core system services such as security, memory management, process management, network stack, and driver model. The kernel also acts as an abstraction layer between the hardware and the rest of the software stack.It helps to manage security, memory management, process management, network stack and other important issues. Therefore, the user should bring Linux in his mobile device as the main operating system and install all the drivers required in order to run it. Developers have full access to the same framework APIs used by the core applications. The application architecture is designed to simplify the reuse of components; any application can publish its capabilities and any other application may then make use of those capabilities (subject to security constraints enforced by the framework). This same mechanism allows components to be replaced by the user.Underlying all applications is a set of services and systems.

Architecture

The following diagram shows the major components of the Android operating system. Each section is described in more detail below.

Architecture Of Android

3. 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. Therefore, the user should bring Linux in his mobile device as the main operating system and install all the drivers required in order to run it. Android provides the support for the Qualcomm MSM7K chipset family. For instance, the current kernel tree supports Qualcomm MSM 7200A chipsets, but in the second half of 2008 we should see mobile devices with stable version Qualcomm MSM 7200, which includes major features:

WCDMA/HSUPA and EGPRS network support Bluetooth 1.2 and Wi-Fi support Digital audio support for mp3 and other formats Support for Linux and other third-party operating systems Java hardware acceleration and support for Java applications Qcamera up to 6.0 megapixels gpsOne solution for GPS and lots of other.

4. 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. For example, Surface Manager is responsible for composing different drawing surfaces on the mobile screen. It manages the access for different processes to compose 2D and 3D graphic layers.OpenGL ES and SGL make a core of graphic libraries and are used accordingly for 3D and 2D hardware acceleration. Moreover, it is possible to use 2D and 3D graphics in the same application in Android. The media framework was provided by PacketVideo, one of the members of OHA. It gives libraries for a playback and recording support for all the major media and static image files. FreeType libraries are used to render all the bitmap and vector fonts. For data storage, Android uses SQLite. As mentioned before, it is extra light rational management system, which locates a single file for all operations related to database. WebKit, the same browser used by Apples Safari, was modified by Android in order to fit better in a small size screens.

5. Android Runtime

At the same level there is Android Runtime, where the main component Dalvik Virtual Machine is located. It was designed specifically for Android running in limited environment, where the limited battery, CPU, memory and data storage are the main issues. Android gives an integrated tool dx, which converts generated byte code from .jar to .dex file, after this byte code becomes much more efficient to run on the small processors.

Conversion from .java to .dex file

As the result, it is possible to have multiple instances of Dalvik virtual machine running on the single device at the same time. The Core libraries are written in Java language and contains of the collection classes, the utilities, IO and other tools.

6. Application FrameworkAfter 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. It has several components.The Activity Manager manages the life circle of the applications and provides a common navigation back stack for applications, which are running in different processes. The Package Manager keeps track of the applications, which are installed in the device. The Windows Manager is Java programming language abstraction on the top of lower level services that are provided by the Surface Manager. The Telephony Manager contains of a set of API necessary for calling applications. Content Providers was built for Android to share a data with other applications, for instance, the contacts of people in the address book can be used in other applications too. The Resource Manager is used to store localized strings, bitmaps, layout file descriptions and other external partsof the application. The View System generates a set of buttons and lists used in UI. Other components like Notification manager is used to customize display alerts and other functions.

7. 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. All applications are written using the Java programming language.

Developing Applications

8. Application Building Blocks

We can think of an Android application as a collection of components, of various kinds. These components are for the most part quite loosely coupled, to the degree where you can accurately describe them as a federation of components rather than a single cohesive application.Generally, these components all run in the same system process. It's possible (and quite common) to create multiple threads within that process, and it's also possible to create completely separate child processes if you need to. Such cases are pretty uncommon though, because Android tries very hard to make processes transparent to your code.Google provides three versions of SDK for Windows, for Mac OSX and one for Linux.The developer can use Android plugin for Eclipse IDE or other IDEs such as intelliJ.First step for Android developer is to decompose the prospective application into the components, which are supported by the platform. The major building blocks are these: Activity Intent Receiver Service Content Provider

1. ActivityUser interface component, which corresponds to one screen at time. It means that for the simple application like Address Book, the developer should have one activity for displaying contacts, another activity component for displaying more detailed information of chosen name and etc.2. Intent ReceiverWakes up a predefined action through the external event. For example,for the application like Email Inbox, the developer should have intent receiver and register his code through XML to wake up an alarm notification, when the user receives email.3. ServiceA task, which is done in the background. It means that the user can start an application from the activity window and keep the service work, while browsing other applications. For instance, he can browse Google Maps application while holding a call or listening music while browsing other applications.4. Content ProviderA component, which allows sharing some of the data with other processes and applications. It is the best way to communicate the applications between each other.Android will ship with a set of core applications including an email client, SMS program, calendar, maps, browser, contacts, and others. All applications are written using the Java programming language.

9. AndroidManifest.xml

The AndroidManifest.xml file is the control file that tells the system what to do with all the top-level components (specifically activities, services, intent receivers, and content providers described below) you've created. For instance, this is the "glue" that actually specifies which Intents your Activities receive.

A developer should predefine and list all components, which he wants to use in the specific AndroidManifest.xml file. It is a required file for all the applications and is located in the root folder. It is possible to specify all global values for the package, all the components and its classes used, intent filters, which describe where and when the certain activity should start, permissions and instrumentation like security control and testing.

Here is an example of AndroidManifest.xml file: 1. 2. 4. 5. 6. 7. 8. 9. 10. 11. 12. The line 2 is a namespace declaration, which makes a standard Android attributes available for that application. In the line 4 there is a single element, where the developer specifies all application level components and its properties used by the package. Activity class in the line 5 represents the initial screen the user sees and it may have one or more elements to describe the actions that activity supports.

10. Application Lifecycle

In Android, every application runs in its own process, which gives better performance in security, protected memory and other benefits. Therefore, Android is responsible to run and shut down correctly these processes when it is needed.

It is important that application developers understand how different application components (in particular Activity, Service, and BroadcastReceiver) impact the lifetime of the application's process. Not using these components correctly can result in the system killing the application's process while it is doing important work.

To determine which processes should be killed when low on memory, Android places each process into an "importance hierarchy" based on the components running in them and the state of those components. These process types are (in order of importance).1. A foreground process is one that is required for what the user is currently doing. Various application components can cause its containing process to be considered foreground in different ways. A process is considered to be in the foreground if any of the following conditions hold:i. It is running an Activity at the top of the screen that the user is interacting with (its onResume() method has been called).ii. It has a BroadcastReceiver that is currently running (its BroadcastReceiver.onReceive() method is executing).iii. It has a Service that is currently executing code in one of its callbacks (Service.onCreate(), Service.onStart(), or Service.onDestroy()).There will only ever be a few such processes in the system, and these will only be killed as a last resort if memory is so low that not even these processes can continue to run. Generally, at this point, the device has reached a memory paging state, so this action is required in order to keep the user interface responsive.2. A visible process is one holding an Activity that is visible to the user on-screen but not in the foreground (its onPause() method has been called). This may occur, for example, if the foreground Activity is displayed as a dialog that allows the previous Activity to be seen behind it. Such a process is considered extremely important and will not be killed unless doing so is required to keep all foreground processes running.3. A service process is one holding a Service that has been started with the startService() method. Though these processes are not directly visible to the user, they are generally doing things that the user cares about (such as background mp3 playback or background network data upload or download), so the system will always keep such processes running unless there is not enough memory to retain all foreground and visible process.4. A background process is one holding an Activity that is not currently visible to the user (its onStop() method has been called). These processes have no direct impact on the user experience. Provided they implement their Activity life-cycle correctly (see Activity for more details), the system can kill such processes at any time to reclaim memory for one of the three previous processes types. Usually there are many of these processes running, so they are kept in an LRU list to ensure the process that was most recently seen by the user is the last to be killed when running low on memory.5. An empty process is one that doesn't hold any active application components. The only reason to keep such a process around is as a cache to improve startup time the next time a component of its application needs to run. As such, the system will often kill these processes in order to balance overall system resources between these empty cached processes and the underlying kernel caches.

Flowchart Showing The Lifecycle Of An Activity

In the following example we will display a process flow from the Android System point of view to get a clear idea how the applications behave. Let assume the

Possible scenario: A user talks to his friend via mobile phone and he is asked to browse the internet (a talk is hold for a moment), find a picture of him in his Picasa Album, send it via Email back to his friend and resume a talk.In this situation, there are 4 different applications and 4 different processes running, but from the user point of view none of them are important, as Android manages CPU work and memory usage by itself. It means the user can travel through the applications forward and back without thinking about how much memory is left or which processes are run at the time.Firstly, as the user is talking to his friend, a specific Talk application is opened, which contains the activity manager. In the following stack we can see two processes running, the main system process and Talk application process. Moreover, before going to Web Browser application, the system saves a Talk state T in order to remember that process:

At this point, as a user holds a talk and opens a web browser, the system creates a new process and new web browser activity is launched in it. Again, the state of the last activity is saved (W):

After that, the user browses the internet, finds his picture in Picasa album and saves it to particular folder. He does not close a web browser, instead he opens a folder to find saved picture. The folder activity is launched in particular process:

At this point, the user finds his saved picture in the folder and he creates a request to open an Email application. The last state F is saved. Now assume that the mobile phone is out of the memory and there is no room to create a new process for Email application. Therefore, Android looks to kill a process. It can not destroy Folder process, as it was used previously and could be reused again, so it kills Web Browser process as it is not useful anymore and locates a new Email process instead:

The user opens Email application and sends a picture to his friend via email. Now he wants to go back to the Talk application and to resume a talk to his friend. Because of the previously saved states, this work is done fast and easily. In this example, Email application is popped out and the user sees a previous Folder application:

Next, the user goes back to Web Browser application. Unfortunately, web browser process was killed previously so the system has to kill another process (in our case it is Email application process, which is not used anymore) in order to locate Web Browser process and manage the stack memory:

and finally:

Now the user comes back to the Talk application and resumes his talk with his friend.Because of the saved states, going back procedure is fast and useful, because it remembers previous activities and its views.This example shows, that it does not matter how many applications and processes are active or how much available memory is left, Android it manages fast and without a user interaction.

11. Application FrameworkDevelopers have full access to the same framework APIs used by the core applications. The application architecture is designed to simplify the reuse of components; any application can publish its capabilities and any other application may then make use of those capabilities (subject to security constraints enforced by the framework). This same mechanism allows components to be replaced by the user.Underlying all applications is a set of services and systems, including: 1. A rich and extensible set of Views that can be used to build an application, including lists, grids, text boxes, buttons, and even an embeddable web browser 2. Content Providers that enable applications to access data from other applications (such as Contacts), or to share their own data 3. A Resource Manager, providing access to non-code resources such as localized strings, graphics, and layout files 4. A Notification Manager that enables all applications to display custom alerts in the status bar 5. An Activity Manager that manages the life cycle of applications and provides a common navigation backstack

12. Library

Android includes a set of C/C++ libraries used by various components of the Android system. These capabilities are exposed to developers through the Android application framework. Some of the core libraries are listed below: System C library - a BSD-derived implementation of the standard C system library (libc), tuned for embedded Linux-based devices Media Libraries - based on PacketVideo's OpenCORE; the libraries support playback and recording of many popular audio and video formats, as well as static image files, including MPEG4, H.264, MP3, AAC, AMR, JPG, and PNG Surface Manager - manages access to the display subsystem and seamlessly composites 2D and 3D graphic layers from multiple applications . LibWebCore - a modern web browser engine which powers both the Android browser and an embeddable web view SGL - the underlying 2D graphics engine 3D libraries - an implementation based on OpenGL ES 1.0 APIs; the libraries use either hardware 3D acceleration (where available) or the included, highly optimized 3D software rasterizer FreeType - bitmap and vector font rendering SQLite - a powerful and lightweight relational database engine available to all applications LINUX COMPATIBILITYAndroid's kernel was derived from Linux but has been tweaked by Google outside the main Linux kernel tree.[145] Android does not have a native X Window System nor does it support the full set of standard GNU libraries, and this makes it difficult to port existing GNU/Linux applications or libraries to Android. However, support for the X Window System is possible. Google no longer maintains the code they previously contributed to the Linux kernel as part of their Android effort, creating a separate version or fork of Linux. This was due to a disagreement about new features Google felt were necessary (some related to security of mobile applications). The code which is no longer maintained was deleted in January 2010 from the Linux codebase. Google announced in April 2010 that they will hire two employees to work with the Linux kernel community. However, as of January 2011, points of contention still exist between Google and the Linux kernel team: Google tried to push upstream some Android-specific power management code in 2009, which is still rejected today. Furthermore, Greg Kroah-Hartman, the current Linux kernel maintainer for the -stable branch, said in December 2010 that he was concerned that Google was no longer trying to get their code changes included in mainstream Linux. Some Google Android developers hinted that "the Android team was getting fed up with the process," because they were a small team and had more urgent work to do on Android.

CLAIMED INFRINGEMENT OF COPYRIGHTS AND PATENTSOn 12 August 2010, Oracle, owner of Java since it acquired Sun Microsystems in April 2009, sued Google over claimed infringement of copyrights and patents. The lawsuit claims that, "In developing Android, Google knowingly, directly and repeatedly infringed Oracle's Java-related intellectual property." Specifically the patent infringement claim references seven patents including United States Patent No. 5,966,702, entitled "Method And Apparatus For Preprocessing And Packaging Class Files," and United States Patent No. 6,910,205, entitled "Interpreting Functions Utilizing A Hybrid Of Virtual And Native Machine Instructions." It also references United States Patent No. RE38,104, ("the '104 patent") entitled Method And Apparatus For Resolving Data References In Generated Code authored by James Gosling, best known as the father of the Java programming language. In response Google submitted multiple lines of defense, saying that Android did not infringe on Oracle's patents or copyright, that Oracle's patents were invalid, and several other defenses. They said that Android is based on Apache Harmony, a clean room implementation of the Java class libraries, and an independently developed virtual machine called Dalvik. The Free Software Foundation has called this suit a "clear attack against someone's freedom to use, share, modify, and redistribute software." However, the FSF also criticized Google, saying that Google could have avoided the suit by building Android on top of IcedTea, whose GPL license provides some protection against patents, instead of implementing it independently under the Apache License. The FSF wrote "It's sad to see that Google apparently shunned those protections in order to make proprietary software development easier on Android." and remarked that Google had not taken any clear position or action against software patents.

CONCLUSION AND FUTURE SCOPEAndroid has been criticized for not being all open-source software despite what was announced by Google. Parts of the SDK are proprietary and closed source, and some believe this is so that Google can control the platform. Software installed by end-users must be written in Java, and will not have access to lower level device APIs. This provides end-users with less control over their phone's functionality than other free and open source phone platforms, such as OpenMoko. With all upcoming applications and mobile services Google Android is stepping into the next level of Mobile Internet. Android participates in many of the successful open source projects. That is, architect the solution for participation and the developers will not only come but will play well together. This is notable contrast with Apple and other companies, where such architecture of participation is clearly belated.The first Android based official devices has been launched sometime in the early half of 2009. Obviously, it's an age away when it comes to handset design, and Android may well find itself competing against the forthcoming Nokia touch screen phones and maybe even the iPhone handsets.

QUESTIONNAIRES.NOQUESTIONYESNO

1Do you use a smart phone?

2Are you aware of any services that improve the performance of Android phones?

3Are you satisfied with the performance of your device?

4Have you noticed that your Android device has slowed or experienced an increase in abnormal behavior since the time of purchase?

5If a company offered an inexpensive service that improved your Android device performance, would you consider contacting that company?

6Overall have you enjoyed your experience with your Android device?

7Do you think KitKat is seeing a higher early adaption rate than Ice cream, Sandwich and Jelly Bean?

8Do you think KitKat 4.4 is the improved version of Android behind Jelly Bean?

9Would you recommend your friends and relatives to use Android device instead of other mobile operating system?

10Would you continue to use Android devices and its improved features in coming years?

BIBLIOGRAPHY

http://www.android.com - Android Official Webpage http://code.google.com/android/ - Official Android Google Code Webpage http://www.openhandsetalliance.com/ - Open Handset Alliance Webpage http://www.androidwiki.com Android Wiki http://googleblog.blogspot.com/ - Official Google Blog http://en.wikipedia.org/wiki/Android_(mobile_phone_platform)Wikipedia Information http://en.wikipedia.org/wiki/SQLite http://en.wikipedia.org/wiki/WebKit http://en.wikipedia.org/wiki/Eclipse_(software) http://www.itworld.com/google-android-dr-080213