Android OS
- 2. Android (operating system) AndroidAndroid is ais a LinuxLinux-based-based operating systemoperating system designed primarily fordesigned primarily for touchscreen mobile devices such as smartphones and tablet computerstouchscreen mobile devices such as smartphones and tablet computers Initially developed byInitially developed by AndroidAndroid, Inc., whom, Inc., whom GoogleGoogle financially backedfinancially backed and later purchasedand later purchased in 2005,in 2005, AndroidAndroid was unveiledwas unveiled in 2007in 2007 along withalong with the founding of thethe founding of the Open Handset AllianceOpen Handset Alliance: a consortium of hardware,: a consortium of hardware, software, and telecommunication companies devoted to advancing opensoftware, and telecommunication companies devoted to advancing open standards for mobile devices.standards for mobile devices. TheThe firstfirst AndroidAndroid-powered phone-powered phone was soldwas sold in October 2008.in October 2008.
- 3. OHA (Open Handset Alliance) A business alliance consisting of 47 companies toA business alliance consisting of 47 companies to develop open standards for mobile devicesdevelop open standards for mobile devices
- 4. AndroidAndroid is open source andis open source and GoogleGoogle releases the code under thereleases the code under the Apache License. This open source code and permissive licensingApache License. This open source code and permissive licensing allows the software to be freely modified and distributed byallows the software to be freely modified and distributed by device manufacturers, wireless carriers and enthusiast developers.device manufacturers, wireless carriers and enthusiast developers. Additionally,Additionally, AndroidAndroid has a large community of developers writinghas a large community of developers writing applications ("apps") that extend the functionality of devices,applications ("apps") that extend the functionality of devices, written primarily in a customized version of thewritten primarily in a customized version of the Java programmingJava programming language.language. InIn October 2012October 2012, there were approximately, there were approximately 700,000 apps700,000 apps available foravailable for AndroidAndroid, and the estimated number of applications, and the estimated number of applications downloaded fromdownloaded from Google PlayGoogle Play,, Android'sAndroid's primary app store, wasprimary app store, was 25 billion.25 billion. Android (operating system)
- 5. These factors have allowedThese factors have allowed AndroidAndroid to become the world's mostto become the world's most widely used smartphone platform and the software of choicewidely used smartphone platform and the software of choice for technology companies who require a low-cost, customizable,for technology companies who require a low-cost, customizable, lightweightlightweight operating systemoperating system for high tech devices withoutfor high tech devices without developing one from scratch. As a result, despite being primarilydeveloping one from scratch. As a result, despite being primarily designed for phones and tablets, it has seen additional applicationsdesigned for phones and tablets, it has seen additional applications onon televisionstelevisions,, games consolesgames consoles andand otherother electronics.electronics. Android'sAndroid's open natureopen nature Android (operating system) officially released running otherofficially released running other for advanced users or bringfor advanced users or bring AndroidAndroid toto for community-driven projects, which add newfor community-driven projects, which add new featuresfeatures enthusiasts to use the open source code as aenthusiasts to use the open source code as a has further encouraged a large community of developershas further encouraged a large community of developers andand devices which weredevices which were operating systems.operating systems.
- 6. Android (operating system) Android had a worldwideAndroid had a worldwide smartphone market sharesmartphone market share ofof 75%75% during theduring the thirdthird quarter of 2012quarter of 2012, with, with 500500 million devicesmillion devices activated inactivated in total andtotal and 1.3 million1.3 million activations per day.activations per day. However, the operatingHowever, the operating system's success has madesystem's success has made it a target for patentit a target for patent litigation as part of thelitigation as part of the so-calledso-called "smartphone"smartphone wars"wars" between technologybetween technology companies.companies.
- 7. HistoryHistory Android, Inc.Android, Inc. was founded inwas founded in Palo Alto,Palo Alto, CaliforniaCalifornia in October 2003in October 2003 byby Andy RubinAndy Rubin (co-founder of Danger),(co-founder of Danger), Rich MinerRich Miner (co-(co- founder of Wildfire Communications, Inc.),founder of Wildfire Communications, Inc.), Nick SearsNick Sears (once VP at T-Mobile),(once VP at T-Mobile), and Chrisand Chris WhiteWhite (headed design and interface(headed design and interface development atdevelopment at WebTVWebTV)) to develop, into develop, in Rubin'sRubin's words "...smarter mobile devices thatwords "...smarter mobile devices that are more aware of its owner's location andare more aware of its owner's location and preferences. "Despite the obvious pastpreferences. "Despite the obvious past accomplishments of the founders and earlyaccomplishments of the founders and early employees, Android Inc. operated secretly,employees, Android Inc. operated secretly, revealing only that it was working on softwarerevealing only that it was working on software for mobile phones.for mobile phones. That same year,That same year, RubinRubin ran out of money.ran out of money. Steve PerlmanSteve Perlman, a close, a close friend offriend of RubinRubin, brought him, brought him $10,000$10,000 in cashin cash in an envelope and refused a stake in thein an envelope and refused a stake in the company.company.
- 8. Speculation aboutSpeculation about Google'sGoogle's intention to enter the mobile communications marketintention to enter the mobile communications market continued to build throughcontinued to build through December 2006.December 2006. Reports from theReports from the BBCBBC andand The Wall StreetThe Wall Street JournalJournal noted thatnoted that GoogleGoogle wanted its search and applications on mobile phones and itwanted its search and applications on mobile phones and it was working hard to deliver that. Print and online media outlets soon reported rumorswas working hard to deliver that. Print and online media outlets soon reported rumors thatthat GoogleGoogle was developing awas developing a GoogleGoogle-branded handset. Some speculated that as-branded handset. Some speculated that as GoogleGoogle was defining technical specifications, it was showing prototypes to cell phonewas defining technical specifications, it was showing prototypes to cell phone manufacturers and network operators.manufacturers and network operators. In September 2007,In September 2007, InformationWeekInformationWeek coveredcovered an Evalueserve study reporting that Google had filed several patent applications in thean Evalueserve study reporting that Google had filed several patent applications in the area of mobile telephony.area of mobile telephony. On November 5, 2007,On November 5, 2007, thethe Open Handset AllianceOpen Handset Alliance, a consortium of technology, a consortium of technology companies including Google, device manufacturers such ascompanies including Google, device manufacturers such as HTCHTC andand SamsungSamsung, wireless, wireless carriers such ascarriers such as Sprint NextelSprint Nextel andand T-MobileT-Mobile, and chipset makers such as, and chipset makers such as QualcommQualcomm andand Texas InstrumentsTexas Instruments, unveiled itself, with a goal to develop open standards for, unveiled itself, with a goal to develop open standards for mobile devices. That day,mobile devices. That day, AndroidAndroid was unveiled as its first product, a mobile devicewas unveiled as its first product, a mobile device platform built on the Linux kernelplatform built on the Linux kernel version 2.6.version 2.6. The first commercially available phone toThe first commercially available phone to runrun AndroidAndroid was thewas the HTC DreamHTC Dream, released, released on October 22, 2008.on October 22, 2008. HistoryHistory
- 9. Since 2008,Since 2008, AndroidAndroid has seen numerous updateshas seen numerous updates which have incrementally improved the operatingwhich have incrementally improved the operating system, adding new features and fixing bugs insystem, adding new features and fixing bugs in previous releases. Each major release is named inprevious releases. Each major release is named in alphabetical order after a dessert or sugary treat;alphabetical order after a dessert or sugary treat; for example,for example, version 1.5 Cupcakeversion 1.5 Cupcake was followed bywas followed by 1.6 Donut1.6 Donut. The latest release is. The latest release is 4.2 Jelly Bean4.2 Jelly Bean.. InIn 2010,2010, GoogleGoogle launched itslaunched its NexusNexus series of devicesseries of devices - a line of smartphones and tablets running the- a line of smartphones and tablets running the AndroidAndroid operating system, and built by aoperating system, and built by a manufacturer partner.manufacturer partner. HTCHTC collaborated withcollaborated with GoogleGoogle to release the firstto release the first NexusNexus smartphone,smartphone, thethe Nexus One.Nexus One. The series has since been updated withThe series has since been updated with newer devices, such as thenewer devices, such as the Galaxy NexusGalaxy Nexus phone andphone and Nexus 7Nexus 7 tablet, made bytablet, made by SamsungSamsung andand AsusAsus respectively.respectively. GoogleGoogle releases thereleases the NexusNexus phones andphones and tablets to act as their flagshiptablets to act as their flagship AndroidAndroid devices,devices, demonstratingdemonstrating Android'sAndroid's latest software andlatest software and hardware features.hardware features. HistoryHistory
- 10. Interface Android'sAndroid's user interface is based on direct manipulation, using touch inputs that looselyuser interface is based on direct manipulation, using touch inputs that loosely correspond to real-world actions, like swiping, tapping, pinching and reverse pinching tocorrespond to real-world actions, like swiping, tapping, pinching and reverse pinching to manipulatemanipulate on-screen objects.on-screen objects. The response to user input is designed to be immediate andThe response to user input is designed to be immediate and provides a fluid touch interface, often using the vibration capabilities of the device toprovides a fluid touch interface, often using the vibration capabilities of the device to provide haptic feedback to the user.provide haptic feedback to the user. Internal hardwareInternal hardware such assuch as accelerometers,accelerometers, gyroscopesgyroscopes and proximityand proximity sensorssensors are used by some applications to respond to additionalare used by some applications to respond to additional user actions, for example adjusting the screen from portrait to landscape depending onuser actions, for example adjusting the screen from portrait to landscape depending on how the device is oriented, or allowing the user to steer a vehicle in ahow the device is oriented, or allowing the user to steer a vehicle in a racing gameracing game byby rotating the device, simulating control of a steering wheel.rotating the device, simulating control of a steering wheel. AndroidAndroid devices boot to thedevices boot to the homescreen,homescreen, the primary navigation and information point onthe primary navigation and information point on the device, which is similar to the desktop foundthe device, which is similar to the desktop found on PCs.on PCs. AndroidAndroid homescreens are typicallyhomescreens are typically made up of app icons and widgets; app icons launch the associated app, whereas widgetsmade up of app icons and widgets; app icons launch the associated app, whereas widgets display live, auto-updating content such as the weather forecast, the user's email inbox, ordisplay live, auto-updating content such as the weather forecast, the user's email inbox, or a news ticker directly on thea news ticker directly on the homescreen.homescreen. AA homescreenhomescreen may be made up of several pagesmay be made up of several pages that the user can swipe back and forth between, thoughthat the user can swipe back and forth between, though Android'sAndroid's homescreen interfacehomescreen interface is heavily customisable, allowing the user to adjust the look and feel of the device to theiris heavily customisable, allowing the user to adjust the look and feel of the device to their tastes. Third party apps available ontastes. Third party apps available on Google PlayGoogle Play and other app stores can extensively re-and other app stores can extensively re- theme thetheme the homescreen,homescreen, and even mimic the look of otherand even mimic the look of other operating systemsoperating systems, such as, such as Windows Phone.Windows Phone. Most manufacturers, and some wireless carriers, customise the look andMost manufacturers, and some wireless carriers, customise the look and feel of theirfeel of their AndroidAndroid devices to differentiate themselves from the competition.devices to differentiate themselves from the competition.
- 11. Interface A Samsung Galaxy Note II's homescreen, showing the status bar, a clock and weather widget, a Google search bar, and several app shortcuts. Present along the top of the screen is a statusPresent along the top of the screen is a status bar, showing information about the device andbar, showing information about the device and its connectivity. Thisits connectivity. This status barstatus bar can becan be "pulled" down to reveal a notification"pulled" down to reveal a notification screenscreen where apps display important information orwhere apps display important information or updates, such as a newly received email orupdates, such as a newly received email or SMS textSMS text, in a way that doesn't immediately, in a way that doesn't immediately interrupt or inconvenience the user.interrupt or inconvenience the user. In earlyIn early versions ofversions of AndroidAndroid these notifications couldthese notifications could be tapped to open the relevant app, butbe tapped to open the relevant app, but recent updates have provided enhancedrecent updates have provided enhanced functionality, such as the ability to call afunctionality, such as the ability to call a number back directly from the missed callnumber back directly from the missed call notification without having to open the dialernotification without having to open the dialer app first. Notifications are persistent untilapp first. Notifications are persistent until read or dismissed by the user.read or dismissed by the user.
- 12. Applications AndroidAndroid has a growing selection of third partyhas a growing selection of third party applications, which can be acquired by users eitherapplications, which can be acquired by users either through an app store such asthrough an app store such as Google PlayGoogle Play or theor the AmazonAmazon Appstore,Appstore, or by downloading and installing theor by downloading and installing the application'sapplication's APK fileAPK file from a third-party site.from a third-party site. TheThe PlayPlay StoreStore application allows users to browse, download andapplication allows users to browse, download and update apps published byupdate apps published by GoogleGoogle and third-partyand third-party developers, and is pre-installed on devices that complydevelopers, and is pre-installed on devices that comply withwith Google'sGoogle's compatibility requirements. The app filterscompatibility requirements. The app filters the list of available applications to those that arethe list of available applications to those that are compatible with the user's device, and developers maycompatible with the user's device, and developers may restrict their applications to particular carriers orrestrict their applications to particular carriers or countries for business reasons.countries for business reasons. Purchases of unwantedPurchases of unwanted applications can be refunded withinapplications can be refunded within 15 minutes15 minutes of theof the time of download, and some carriers offer direct carriertime of download, and some carriers offer direct carrier billing forbilling for Google PlayGoogle Play application purchases, where theapplication purchases, where the cost of the application is added to the user's monthlycost of the application is added to the user's monthly bill. Asbill. As of September 2012of September 2012, there were more than, there were more than 675,000 apps675,000 apps available foravailable for Android,Android, and the estimatedand the estimated number of applications downloaded from thenumber of applications downloaded from the Play StorePlay Store waswas 25 billion.25 billion.
- 13. Applications ApplicationsApplications are developed in theare developed in the Java languageJava language using theusing the AndroidAndroid software development kitsoftware development kit (SDK).(SDK). TheThe SDKSDK includes a comprehensive set ofincludes a comprehensive set of development tools,development tools, including a debugger,including a debugger, software libraries, a handset emulator based onsoftware libraries, a handset emulator based on QEMU,QEMU, documentation, sample code, anddocumentation, sample code, and tutorials. The officially supported integratedtutorials. The officially supported integrated development environmentdevelopment environment (IDE)(IDE) isis EclipseEclipse usingusing thethe AndroidAndroid Development ToolsDevelopment Tools (ADT)(ADT) plugin.plugin. Other development tools are available, includingOther development tools are available, including a Nativea Native Development KitDevelopment Kit for applications orfor applications or extensions inextensions in C or C++,C or C++, Google App InventorGoogle App Inventor, a, a visual environment for novice programmers, andvisual environment for novice programmers, and various cross platform mobile web applicationsvarious cross platform mobile web applications frameworks.frameworks. In order to work around limitations on reachingIn order to work around limitations on reaching GoogleGoogle services due to Internet censorship inservices due to Internet censorship in thethe People's Republic of ChinaPeople's Republic of China,, AndroidAndroid devicesdevices sold in thesold in the PRCPRC are generally customized to useare generally customized to use state approved services instead.state approved services instead.
- 14. AndroidAndroid • A S/W stack for mobile devices developedA S/W stack for mobile devices developed and managed by OHAand managed by OHA • A free S/W under Apache LicenseA free S/W under Apache License Operating System (Linux Kernel 2.6)Operating System (Linux Kernel 2.6) MiddlewareMiddleware Key ApplicationsKey Applications AndroidAndroid
- 17. Android S/W Stack -Android S/W Stack - ApplicationApplication Android provides a set of core applications:Android provides a set of core applications: Email ClientEmail Client SMS ProgramSMS Program CalendarCalendar MapsMaps BrowserBrowser ContactsContacts EtcEtc AllAll applicationsapplications areare writtenwritten using theusing the Java language.Java language.
- 18. Android S/W Stack – App Framework Enabling and simplifying the reuse ofEnabling and simplifying the reuse of componentscomponents Developers have full access to the sameDevelopers have full access to the same framework APIs used by the core applications.framework APIs used by the core applications. Users are allowed to replace components.Users are allowed to replace components.
- 19. Android S/W Stack -Android S/W Stack - LibrariesLibraries • Including a set of C/C++ libraries used by components of the Android system • Exposed to developers through the Android application framework
- 20. Android S/W Stack -Android S/W Stack - RuntimeRuntime Core LibrariesCore Libraries Providing most of the functionality available inProviding most of the functionality available in the core libraries of the Java languagethe core libraries of the Java language APIsAPIs Data StructuresData Structures UtilitiesUtilities File AccessFile Access Network AccessNetwork Access GraphicsGraphics EtcEtc
- 21. Android S/W Stack – LinuxAndroid S/W Stack – Linux KernelKernel Relying on Linux Kernel 2.6 for core system servicesRelying on Linux Kernel 2.6 for core system services Memory and Process ManagementMemory and Process Management Network StackNetwork Stack Driver ModelDriver Model SecuritySecurity Providing an abstraction layer between the H/W and the rest ofProviding an abstraction layer between the H/W and the rest of the S/W stackthe S/W stack
- 22. Memory managementMemory management SinceSince AndroidAndroid devices are usually battery-powered,devices are usually battery-powered, AndroidAndroid is designed tois designed to managemanage memorymemory (RAM)(RAM) to keep power consumption at a minimum, in contrast toto keep power consumption at a minimum, in contrast to desktopdesktop operating systemsoperating systems which generally assume they are connected towhich generally assume they are connected to unlimited mains electricity. When anunlimited mains electricity. When an AndroidAndroid app is no longer in use, the systemapp is no longer in use, the system will automatically suspend it inwill automatically suspend it in memorymemory - while the- while the appapp is still technically "open,"is still technically "open," suspendedsuspended appsapps consume no resourcesconsume no resources (e.g. battery power or processing power)(e.g. battery power or processing power) and sit idly in the background until needed again. This has the dual benefit ofand sit idly in the background until needed again. This has the dual benefit of increasing the general responsiveness ofincreasing the general responsiveness of AndroidAndroid devices, since apps don't needdevices, since apps don't need to be closed and reopened from scratch each time, but also ensuring backgroundto be closed and reopened from scratch each time, but also ensuring background appsapps don't waste power needlessly.don't waste power needlessly. AndroidAndroid manages the apps stored in memory automatically: whenmanages the apps stored in memory automatically: when memorymemory is low,is low, the system will begin killingthe system will begin killing appsapps and processes that have been inactive for aand processes that have been inactive for a while, in reverse order since they were last usedwhile, in reverse order since they were last used (i.e. oldest first).(i.e. oldest first). This processThis process is designed to be invisible to the user, such that users do not need to manageis designed to be invisible to the user, such that users do not need to manage memorymemory or the killing ofor the killing of appsapps themselves. However, confusion overthemselves. However, confusion over AndroidAndroid memory managementmemory management has resulted in third-party task killers becoming popular onhas resulted in third-party task killers becoming popular on thethe Google Play storeGoogle Play store; these third-party task killers are generally regarded as; these third-party task killers are generally regarded as doing more harm than good.doing more harm than good.
- 23. Usage share of Android versionsUsage share of Android versions
- 24. Any Questions ?Any Questions ? www.google.com :Pwww.google.com :P