OS Android

Android (operating system)

AndroidAndroid is a is a LinuxLinux-based -based operating system operating system designed primarily for designed primarily for touchscreen mobile devices such as smartphones and tablet computers.touchscreen mobile devices such as smartphones and tablet computers. Initially developed by Initially developed by AndroidAndroid, Inc., whom , Inc., whom GoogleGoogle financially backed financially backed and later purchased and later purchased in 2005, in 2005, Android Android was unveiled was unveiled in 2007 in 2007 along with along with the founding of the the 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. The The firstfirst AndroidAndroid-powered phone -powered phone was sold was sold in October 2008.in October 2008.

OHA (Open Handset Alliance)

A business alliance consisting of 47 companies to A business alliance consisting of 47 companies to develop open standards for mobile devicesdevelop open standards for mobile devices

AndroidAndroid is open source and is open source and GoogleGoogle releases the code under the releases 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 by allows 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 writing has 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 the written primarily in a customized version of the Java programming Java programming language.language. In In October 2012October 2012, there were approximately , there were approximately 700,000 apps 700,000 apps available for available for AndroidAndroid, and the estimated number of applications, and the estimated number of applications downloaded from downloaded from Google PlayGoogle Play, , Android'sAndroid's primary app store, was primary app store, was 25 billion.25 billion.

Android (operating system)

These factors have allowed These factors have allowed AndroidAndroid to become the world's most to become the world's most widely used smartphone platform and the software of choice widely 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, lightweight lightweight operating system operating system for high tech devices withoutfor high tech devices without developing one from scratch. As a result, despite being primarily developing one from scratch. As a result, despite being primarily designed for phones and tablets, it has seen additional applications designed for phones and tablets, it has seen additional applications on on televisionstelevisions, , games consoles games consoles and and otherother electronics. electronics. Android'sAndroid's open nature open nature

Android (operating system)

officially released running otherofficially released running otherfor advanced users or bring for advanced users or bring AndroidAndroid to to

for community-driven projects, which add new for community-driven projects, which add new featuresfeatures

enthusiasts to use the open source code as aenthusiasts to use the open source code as ahas further encouraged a large community of developers has further encouraged a large community of developers and and

devices which weredevices which were

operating systems.operating systems.

Android (operating system)

Android had a Android had a worldwide smartphone worldwide smartphone market share of market share of 75% 75% during the during the third quarter third quarter of 2012of 2012, with , with 500 500 million devices million devices activated in total and activated in total and 1.3 million activations 1.3 million activations per day. per day. However, the However, the operating system's operating system's success has made it a success has made it a target for patent target for patent litigation as part of the litigation as part of the so-called so-called "smartphone "smartphone wars" wars" between between technology companies.technology companies.

HistoryHistory

Android, Inc. Android, Inc. was founded in was founded in Palo Alto, Palo Alto, CaliforniaCalifornia in October 2003 in October 2003 by by Andy Rubin Andy Rubin (co-founder of Danger),(co-founder of Danger), Rich Miner Rich 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 Chris and Chris White White (headed design and interface (headed design and interface development at development at WebTVWebTV)) to develop, in to develop, in Rubin'sRubin's words "...smarter mobile devices that words "...smarter mobile devices that are more aware of its owner's location and are more aware of its owner's location and preferences. "Despite the obvious past preferences. "Despite the obvious past accomplishments of the founders and early accomplishments of the founders and early employees, Android Inc. operated secretly, employees, Android Inc. operated secretly, revealing only that it was working on software revealing 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 of friend of RubinRubin, brought him , brought him $10,000 $10,000 in cash in cash in an envelope and refused a stake in the in an envelope and refused a stake in the company.company.

Speculation about Speculation about Google'sGoogle's intention to enter the mobile communications intention to enter the mobile communications market continued to build through market continued to build through December 2006.December 2006. Reports from the Reports from the BBC BBC and and The Wall Street JournalThe Wall Street Journal noted that noted that GoogleGoogle wanted its search and wanted its search and applications on mobile phones and it was working hard to deliver that. Print applications on mobile phones and it was working hard to deliver that. Print and online media outlets soon reported rumors that and online media outlets soon reported rumors that Google Google was developing was developing a a GoogleGoogle-branded handset. Some speculated that as -branded handset. Some speculated that as GoogleGoogle was defining was defining technical specifications, it was showing prototypes to cell phone technical specifications, it was showing prototypes to cell phone manufacturers and network operators. manufacturers and network operators. In September 2007, In September 2007, InformationWeekInformationWeek covered an Evalueserve study reporting that Google had covered an Evalueserve study reporting that Google had filed several patent applications in the area of mobile telephony.filed several patent applications in the area of mobile telephony.On November 5, 2007,On November 5, 2007, the the Open Handset AllianceOpen Handset Alliance, a consortium of , a consortium of technology companies including Google, device manufacturers such as technology companies including Google, device manufacturers such as HTCHTC and and SamsungSamsung, wireless carriers such as , wireless carriers such as Sprint Nextel Sprint Nextel and and T-MobileT-Mobile, and , and chipset makers such as chipset makers such as Qualcomm Qualcomm and and Texas InstrumentsTexas Instruments, unveiled itself, , unveiled itself, with a goal to develop open standards for mobile devices. That day, with a goal to develop open standards for mobile devices. That day, Android Android was unveiled as its first product, a mobile device platform built on the Linux was unveiled as its first product, a mobile device platform built on the Linux kernel kernel version 2.6.version 2.6. The first commercially available phone to run The first commercially available phone to run AndroidAndroid was the was the HTC DreamHTC Dream, released , released on October 22, 2008.on October 22, 2008.

HistoryHistory

Since 2008, Since 2008, Android Android has seen numerous has seen numerous updates which have incrementally improved updates which have incrementally improved the operating system, adding new features the operating system, adding new features and fixing bugs in previous releases. Each and fixing bugs in previous releases. Each major release is named in alphabetical order major release is named in alphabetical order after a dessert or sugary treat; for example, after a dessert or sugary treat; for example, version 1.5 Cupcake version 1.5 Cupcake was followed by was followed by 1.6 1.6 DonutDonut. The latest release is . The latest release is 4.2 Jelly Bean4.2 Jelly Bean. . In In 2010, 2010, GoogleGoogle launched its launched its NexusNexus series of series of devices - a line of smartphones and tablets devices - a line of smartphones and tablets running the running the AndroidAndroid operating system, and operating system, and built by a manufacturer partner. built by a manufacturer partner. HTCHTC collaborated with collaborated with GoogleGoogle to release the first to release the first NexusNexus smartphone, smartphone, the the Nexus One. Nexus One. The The series has since been updated with newer series has since been updated with newer devices, such as the devices, such as the Galaxy Nexus Galaxy Nexus phone phone and and Nexus 7 Nexus 7 tablet, made by tablet, made by SamsungSamsung and and Asus Asus respectively. respectively. Google Google releases the releases the Nexus Nexus phones and tablets to act as their phones and tablets to act as their flagship flagship AndroidAndroid devices, demonstrating devices, demonstrating Android'sAndroid's latest software and hardware latest software and hardware features.features.

HistoryHistory

InterfaceAndroid'sAndroid's user interface is based on direct manipulation, using touch inputs that user interface is based on direct manipulation, using touch inputs that loosely correspond to real-world actions, like swiping, tapping, pinching and reverse loosely correspond to real-world actions, like swiping, tapping, pinching and reverse pinching to manipulate pinching to manipulate on-screen objects. on-screen objects. The response to user input is designed to The response to user input is designed to be immediate and provides a fluid touch interface, often using the vibration be immediate and provides a fluid touch interface, often using the vibration capabilities of the device to provide haptic feedback to the user. capabilities of the device to provide haptic feedback to the user. Internal hardware Internal hardware such as such as accelerometers, gyroscopesaccelerometers, gyroscopes and proximity and proximity sensorssensors are used by some are used by some applications to respond to additional user actions, for example adjusting the screen applications to respond to additional user actions, for example adjusting the screen from portrait to landscape depending on how the device is oriented, or allowing the from portrait to landscape depending on how the device is oriented, or allowing the user to steer a vehicle in a user to steer a vehicle in a racing game racing game by rotating the device, simulating control by rotating the device, simulating control of a steering wheel.of a steering wheel.Android Android devices boot to the devices boot to the homescreen, homescreen, the primary navigation and information the primary navigation and information point on the device, which is similar to the desktop found point on the device, which is similar to the desktop found on PCs. on PCs. AndroidAndroid homescreens are typically made up of app icons and widgets; app icons launch the homescreens are typically made up of app icons and widgets; app icons launch the associated app, whereas widgets display live, auto-updating content such as the associated app, whereas widgets display live, auto-updating content such as the weather forecast, the user's email inbox, or a news ticker directly on the weather forecast, the user's email inbox, or a news ticker directly on the homescreen.homescreen. A A homescreenhomescreen may be made up of several pages that the user can may be made up of several pages that the user can swipe back and forth between, though swipe back and forth between, though Android's Android's homescreen interface is heavily homescreen interface is heavily customisable, allowing the user to adjust the look and feel of the device to their customisable, allowing the user to adjust the look and feel of the device to their tastes. Third party apps available on tastes. Third party apps available on Google Play Google Play and other app stores can and other app stores can extensively re-theme the extensively re-theme the homescreen,homescreen, and even mimic the look of other and even mimic the look of other operating operating systemssystems, such as , such as Windows Phone. Windows Phone. Most manufacturers, and some wireless carriers, Most manufacturers, and some wireless carriers, customise the look and feel of their customise the look and feel of their Android Android devices to differentiate themselves from devices to differentiate themselves from the competition.the competition.

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 Present along the top of the screen is a status bar, showing information about the status bar, showing information about the device and its connectivity. This device and its connectivity. This status bar status bar can be "pulled" down to reveal a can be "pulled" down to reveal a notification notification screenscreen where apps display where apps display important information or updates, such as important information or updates, such as a newly received email or a newly received email or SMS textSMS text, in a , in a way that doesn't immediately interrupt or way that doesn't immediately interrupt or inconvenience the user.inconvenience the user. In early versions In early versions of of AndroidAndroid these notifications could be these notifications could be tapped to open the relevant app, but tapped to open the relevant app, but recent updates have provided enhanced recent updates have provided enhanced functionality, such as the ability to call a functionality, such as the ability to call a number back directly from the missed call number back directly from the missed call notification without having to open the notification without having to open the dialer app first. Notifications are persistent dialer app first. Notifications are persistent until read or dismissed by the user.until read or dismissed by the user.

ApplicationsAndroidAndroid has a growing selection of third party has a growing selection of third party applications, which can be acquired by users applications, which can be acquired by users either through an app store such as either through an app store such as Google Play Google Play or the or the AmazonAmazon Appstore, Appstore, or by downloading and or by downloading and installing the application's installing the application's APK file APK file from a third-from a third-party site.party site. The The Play StorePlay Store application allows users application allows users to browse, download and update apps published to browse, download and update apps published by by GoogleGoogle and third-party developers, and is pre- and third-party developers, and is pre-installed on devices that comply with installed on devices that comply with Google'sGoogle's compatibility requirements. The app filters the compatibility requirements. The app filters the list of available applications to those that are list of available applications to those that are compatible with the user's device, and developers compatible with the user's device, and developers may restrict their applications to particular may restrict their applications to particular carriers or countries for business reasons.carriers or countries for business reasons.

Purchases of unwanted applications can be Purchases of unwanted applications can be refunded within refunded within 15 minutes15 minutes of the time of of the time of download, and some carriers offer direct carrier download, and some carriers offer direct carrier billing for billing for Google Play Google Play application purchases, application purchases, where the cost of the application is added to the where the cost of the application is added to the user's monthly bill. As user's monthly bill. As of September 2012of September 2012, there , there were more than were more than 675,000 apps 675,000 apps available for available for Android, Android, and the estimated number of and the estimated number of applications downloaded from the applications downloaded from the Play Store Play Store was was 25 billion.25 billion.

Applications

Applications Applications are developed in the are developed in the Java Java language language using the using the AndroidAndroid software software development kit development kit (SDK). (SDK). The The SDKSDK includes a includes a comprehensive set of development tools,comprehensive set of development tools,

including a debugger, software libraries, a including a debugger, software libraries, a handset emulator based on handset emulator based on QEMU,QEMU, documentation, sample code, and tutorials. documentation, sample code, and tutorials. The officially supported integrated The officially supported integrated development environment development environment (IDE) (IDE) is is EclipseEclipse using the using the Android Android Development Tools Development Tools (ADT) (ADT) plugin. Other development tools are plugin. Other development tools are available, including a Native available, including a Native Development Development Kit Kit for applications or extensions in for applications or extensions in C or C+C or C++, +, Google App InventorGoogle App Inventor, a visual , a visual environment for novice programmers, and environment for novice programmers, and various cross platform mobile web various cross platform mobile web applications frameworks.applications frameworks.In order to work around limitations on In order to work around limitations on reaching reaching Google Google services due to Internet services due to Internet censorship in the censorship in the People's Republic of ChinaPeople's Republic of China, , Android Android devices sold in the devices sold in the PRCPRC are are generally customized to use state approved generally customized to use state approved services instead.services instead.

AndroidAndroid

• A S/W stack for mobile devices A S/W stack for mobile devices developed and managed by OHAdeveloped and 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

DevelopmentDevelopment

Android Software Stack

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

All All applicationsapplications are are writtenwritten using the using the Java language.Java language.

Android S/W Stack – App Framework

Enabling and simplifying the reuse of Enabling and simplifying the reuse of componentscomponentsDevelopers have full access to the same Developers have full access to the same

framework APIs used by the core framework APIs used by the core applications.applications.

Users are allowed to replace Users are allowed to replace components.components.

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

Android S/W Stack - Android S/W Stack - RuntimeRuntime

Core LibrariesCore Libraries Providing most of the functionality Providing most of the functionality

available in the core libraries of the available in the core libraries of the Java languageJava language

APIsAPIsData StructuresData StructuresUtilitiesUtilitiesFile AccessFile AccessNetwork AccessNetwork AccessGraphicsGraphicsEtcEtc

Android S/W Stack – Linux Android 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 Memory and Process

ManagementManagement

Network StackNetwork Stack

Driver ModelDriver Model

SecuritySecurity Providing an abstraction layer between the H/W and the rest of Providing an abstraction layer between the H/W and the rest of the S/W stack the S/W stack

Memory managementMemory managementSince Since Android Android devices are usually battery-powered, devices are usually battery-powered, AndroidAndroid is designed to is designed to manage manage memorymemory (RAM) (RAM) to keep power consumption at a minimum, in to keep power consumption at a minimum, in contrast to desktop contrast to desktop operating systems operating systems which generally assume they are which generally assume they are connected to unlimited mains electricity. When an connected to unlimited mains electricity. When an AndroidAndroid app is no longer app is no longer in use, the system will automatically suspend it in in use, the system will automatically suspend it in memorymemory - while the - while the appapp is still technically "open," suspended is still technically "open," suspended appsapps consume no resources consume no resources (e.g. (e.g. battery power or processing power)battery power or processing power) and sit idly in the background and sit idly in the background until needed again. This has the dual benefit of increasing the general until needed again. This has the dual benefit of increasing the general responsiveness of responsiveness of AndroidAndroid devices, since apps don't need to be closed and devices, since apps don't need to be closed and reopened from scratch each time, but also ensuring background reopened from scratch each time, but also ensuring background appsapps don't don't waste power needlessly.waste power needlessly.AndroidAndroid manages the apps stored in memory automatically: when manages the apps stored in memory automatically: when memory memory is low, the system will begin killing is low, the system will begin killing apps apps and processes that have been and processes that have been inactive for a while, in reverse order since they were last used inactive for a while, in reverse order since they were last used (i.e. oldest (i.e. oldest first). first). This process is designed to be invisible to the user, such that users This process is designed to be invisible to the user, such that users do not need to manage do not need to manage memory memory or the killing of or the killing of appsapps themselves. themselves. However, confusion over However, confusion over AndroidAndroid memory management memory management has resulted in has resulted in third-party task killers becoming popular on the third-party task killers becoming popular on the Google Play storeGoogle Play store; these ; these third-party task killers are generally regarded as doing more harm than third-party task killers are generally regarded as doing more harm than good.good.

Usage share of Android versionsUsage share of Android versions

Any Questions ?Any Questions ?

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