A small overview about Android OS

1. OS Android
Romashko Artyom
Supervision:
Chernyakova E.A.

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

15. DevelopmentDevelopment

16. Android Software Stack

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 ?
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