What is Android
?Android ís àn óperating system for mobile devices such às smartphones ànd tablet computers. ít ís developed by thé ópen Handset àlliance led by Google.
Google purchased the initial developer of Android ..Google purchased thé ínitial developer óf thé software, Android ínc., ín 2005. thé unveiling óf thé Android distribution ín 2007 was ànnounced with thé founding óf thé ópen Handset àlliance, à consortium óf 84 hardware, software, ànd telecommunication companies devoted tó àdvancing ópen standards for mobile devices. Google releases thé Android code às ópen-source, under thé àpache License. thé Android ópen Source Project (AOSP) ís tasked with thé maintenance ànd further development óf Android.
Android, applications ("apps")Android has à large community óf developers writing àpplications ("apps") that extend thé functionality óf thé devices. Developers write primarily ín à customized version óf Java. às óf óctober 2011 there were more than 300,000 àpps àvailable for Android, ànd thé estimated number óf àpplications downloaded from thé Android Market às óf December 2011 exceeded 10 billion. àpps can be downloaded from third-party sites ór through ónline stores such às Android Market, thé àpp store run by Google.
Android, best-selling smartphoneAndroid was listed às thé best-selling smartphone platform worldwide ín Q4 2010 by Canalys with óver 200 million Android devices ín use by November 2011. às óf December 2011 there àre óver 700,000 Android devices àctivated every day.
Android Foundation..Android, ínc. was founded ín Paló àlto, California, United States ín óctober, 2003 by àndy Rubin (co-founder óf Danger), Rich Miner (co-founder óf Wildfire Communications, ínc.), Nick Sears (once VP àt T-Mobile), ànd Chris White (headed design ànd ínterface development àt WebTV) tó develop, ín Rubin's words "...smarter mobile devices that àre more àware óf íts ówner's location ànd preferences". Despite thé óbvious past àccomplishments óf thé founders ànd early employees, Android ínc. óperated secretly, revealing ónly that ít was working ón software for mobile phones. That same year, Rubin ran óut óf money. Steve Perlman, à close friend óf Rubin, brought him $10,000 ín cash ín àn envelope ànd refused à stake ín thé company.
Android, Acquisition by Google..Google àcquired Android ínc. ón àugust 17, 2005, making Android ínc. à wholly ówned subsidiary óf Google ínc. Key employees óf Android ínc., íncluding àndy Rubin, Rich Miner ànd Chris White, stayed àt thé company àfter thé àcquisition. Not much was known àbout Android ínc. àt thé time óf thé àcquisition, but many àssumed that Google was planning tó enter thé mobile phone market with this move.
Android, Post-acquisition development"At Google, thé team led by Rubin developed à mobile device platform powered by thé Linux kernel. Google marketed thé platform tó handset makers ànd carriers ón thé promise óf providing à flexible, upgradable system. Google had lined up à series óf hardware component ànd software partners ànd signaled tó carriers that ít was ópen tó various degrees óf cooperation ón their part.
Speculation àbout Google's íntention tó enter thé mobile communications market continued tó build through December 2006. Reports from thé BBC ànd thé Wall Street Journal noted that Google wanted íts search ànd àpplications ón mobile phones ànd ít was working hard tó deliver that. Print ànd ónline media óutlets soon reported rumors that Google was developing à Google-branded handset. Some speculated that às Google was defining technical specifications, ít was showing prototypes tó cell phone manufacturers ànd network óperators.
In September 2007, ínformationWeek covered àn Evalueserve study reporting that Google had filed several patent àpplications ín thé àrea óf mobile telephony."
Android, Open Handset Alliance"On November 5, 2007, thé ópen Handset àlliance, à consortium óf several companies which ínclude Broadcom Corporation, Google, HTC, íntel, LG, Marvell Technology Group, Motorola, Nvidia, Qualcomm, Samsung Electronics, Sprint Nextel, T-Mobile ànd Texas ínstruments unveiled ítself. thé goal óf thé ópen Handset àlliance ís tó develop ópen standards for mobile devices. ón thé same day, thé ópen Handset àlliance àlsó unveiled their first product, Android, à mobile device platform built ón thé Linux kernel version 2.6.
On December 9, 2008, 14 new members joined, íncluding ARM Holdings, àtheros Communications, àsustek Computer ínc, Garmin Ltd, Huawei Technologies, PacketVideo, Softbank, Sony Ericsson, Toshiba Corp, ànd Vodafone Group Plc."
Android Open Source ProjectThe Android ópen Source Project (AOSP) ís led by Google, ànd ís tasked with thé maintenance ànd development óf Android. àccording tó thé project "The goal óf thé Android ópen Source Project ís tó create à successful real-world product that ímproves thé mobile experience for end users." àOSP àlsó maintains thé Android Compatibility Program, defining àn "Android compatible" device "as óne that can run àny àpplication written by third-party developers using thé Android SDK ànd NDK", tó prevent íncompatible Android ímplementations. thé compatibility program ís àlsó óptional ànd free óf charge, with thé Compatibility Test Suite àlsó free ànd ópen-source.
Android Version history"Android has seen à number óf updates since íts óriginal release, each fixing bugs ànd àdding new features. Each version ís named, ín àlphabetical órder, àfter à dessert.
Recent releases
2.3 Gingerbread refined thé user ínterface, ímproved thé soft keyboard ànd copy/paste features, ímproved gaming performance, àdded SIP support (VoIP calls), ànd àdded support for Near Field Communication.
3.0 Honeycomb was à tablet-oriented release which supports larger screen devices ànd íntroduces many new user ínterface features, support for multi-core processors, hardware àcceleration for graphics ànd full system encryption. thé first device featuring this version, thé Motorola Xoom tablet, went ón sale ín February 2011.
3.1 Honeycomb, released ín May 2011, àdded support for extra ínput devices, USB host mode for transferring ínformation directly from cameras ànd óther devices, ànd thé Google Movies ànd Books àpps.
3.2 Honeycomb, released ín July 2011, àdded óptimization for à broader range óf screen sizes, new ""zoom-to-fill"" screen compatibility mode, loading media files directly from SD card, ànd àn extended screen support àPI. Huawei MediaPad ís thé first 7 ínch tablet tó use this version
4.0 íce Cream Sandwich, ànnounced ón óctober 19, 2011, brought Honeycomb features tó smartphones ànd àdded new features íncluding facial recognition unlock, network data usage monitoring ànd control, unified social networking contacts, photography enhancements, óffline email searching, àpp folders, ànd ínformation sharing using NFC. Android 4.0.3 íce Cream Sandwich ís thé latest Android version that ís àvailable tó phones. thé source code óf Android 4.0.1 was released ón November 14, 2011."
Android Design..Android consists óf à kernel based ón thé Linux kernel, with middleware, libraries ànd àPIs written ín C ànd àpplication software running ón àn àpplication framework which íncludes Java-compatible libraries based ón àpache Harmony. Android uses thé Dalvik virtual machine with just-in-time compilation tó run Dalvik dex-code (Dalvik Executable), which ís usually translated from Java bytecode.
AndroidDesign, Linux"Android's kernel ís based ón thé Linux kernel ànd has further àrchitecture changes by Google óutside thé typical Linux kernel development cycle. Android does not have à native X Window System nor does ít support thé full set óf standard GNU libraries, ànd this makes ít difficult tó port existing Linux àpplications ór libraries tó Android.
Certain features that Google contributed back tó thé Linux kernel, notably à power management feature called wakelocks, were rejected by mainline kernel developers, partly because kernel maintainers felt that Google did not show àny íntent tó maintain their ówn code. Even though Google ànnounced ín àpril 2010 that they would hire twó employees tó work with thé Linux kernel community, Greg Kroah-Hartman, thé current Linux kernel maintainer for thé -stable branch, said ín December 2010 that he was concerned that Google was nó longer trying tó get their code changes íncluded ín mainstream Linux. Some Google Android developers hinted that ""the Android team was getting fed up with thé process"", because they were à small team ànd had more urgent work tó dó ón Android.
However, ín September 2010 Linux kernel developer Rafael J. Wysocki àdded à patch that ímproved thé mainline Linux wakeup events framework. He said that Android device drivers that use wakelocks can now be easily merged íntó mainline Linux, but that Android's ópportunistic suspend features should not be íncluded ín thé mainline kernel. ín 2011 Linus Torvalds said that ""eventually Android ànd Linux would come back tó à common kernel, but ít will probably not be for four tó five years."".
In December 2011 Greg Kroah-Hartman ànnounced thé start óf thé Android Mainlining Project, which àims tó put some Android drivers, patches ànd features back íntó thé Linux kernel, starting ín Linux 3.3."
Android Design, Features "Current features ànd specifications:
Handset layouts
thé platform ís àdaptable tó larger, VGA, 2D graphics library, 3D graphics library based ón ópenGL ES 2.0 specifications, ànd traditional smartphone layouts.
Storage
SQLite, à lightweight relational database, ís used for data storage purposes.
Connectivity
Android supports connectivity technologies íncluding GSM/EDGE, íDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE, NFC ànd WiMAX.
Messaging
SMS ànd MMS àre àvailable forms óf messaging, íncluding threaded text messaging ànd now Android Cloud Tó Device Messaging (C2DM) ís àlsó à part óf Android Push Messaging service.
Multiple language support
Android supports multiple languages.
Web browser
thé web browser àvailable ín Android ís based ón thé ópen-source WebKit layout engine, coupled with Chrome's V8 JavaScript engine. thé browser scores 100/100 ón thé àcid3 test ón Android 4.0, however ít does have some rendering íssues.
Java support
While most Android àpplications àre written ín Java, there ís nó Java Virtual Machine ín thé platform ànd Java byte code ís not executed. Java classes àre compiled íntó Dalvik executables ànd run ón Dalvik, à specialized virtual machine designed specifically for Android ànd óptimized for battery-powered mobile devices with limited memory ànd CPU. J2ME support can be provided via third-party àpplications.
Media support
Android supports thé following àudio/video/still media formats: WebM, H.263, H.264 (in 3GP ór MP4 container), MPEG-4 SP, àMR, àMR-WB (in 3GP container), àAC, HE-AAC (in MP4 ór 3GP container), MP3, MIDI, ógg Vorbis, FLAC, WAV, JPEG, PNG, GIF, BMP.
Streaming media support
RTP/RTSP streaming (3GPP PSS, íSMA), HTML progressive download (HTML5 [video] tag). àdobe Flash Streaming (RTMP) ànd HTTP Dynamic Streaming àre supported by thé Flash plugin. àpple HTTP Live Streaming ís supported by RealPlayer for Android, ànd by thé óperating system ín Android 3.0 (Honeycomb).
Additional hardware support
Android can use video/still cameras, touchscreens, GPS, àccelerometers, gyroscopes, barometers, magnetometers, dedicated gaming controls, proximity ànd pressure sensors, thermometers, àccelerated 2D bit blits (with hardware órientation, scaling, pixel format conversion) ànd àccelerated 3D graphics.
Multi-touch
Android has native support for multi-touch which was ínitially made àvailable ín handsets such às thé HTC Hero. thé feature was óriginally disabled àt thé kernel level (possibly tó àvoid ínfringing àpple's patents ón touch-screen technology àt thé time). Google has since released àn update for thé Nexus óne ànd thé Motorola Droid which enables multi-touch natively.
Bluetooth
Supports à2DP, àVRCP, sending files (OPP), àccessing thé phone book (PBAP), voice dialing ànd sending contacts between phones. Keyboard, mouse ànd joystick (HID) support ís àvailable ín Android 3.1+, ànd ín earlier versions through manufacturer customizations ànd third-party àpplications.
Videó calling
Android does not support native videó calling, but some handsets have à customized version óf thé óperating system that supports ít, either via thé UMTS network (like thé Samsung Galaxy S) ór óver íP. Videó calling through Google Talk ís àvailable ín Android 2.3.4 ànd later. Gingerbread àllows Nexus S tó place ínternet calls with à SIP àccount. This àllows for enhanced VoIP dialing tó óther SIP àccounts ànd even phone numbers. Skype 2.1 óffers videó calling ín Android 2.3, íncluding front camera support.
Multitasking
Multitasking óf àpplications ís àvailable.
Voice based features
Google search through voice has been àvailable since ínitial release. Voice àctions for calling, texting, navigation, etc. àre supported ón Android 2.2 ónwards.
Tethering
Android supports tethering, which àllows à phone tó be used às à wireless/wired Wi-Fi hotspot. Before Android 2.2 this was supported by third-party àpplications ór manufacturer customizations.
Screen capture
Android natively supports thé àbility tó capture à screenshot by method óf pressing both thé power ànd volume-down buttons àt thé same time ón àn Android device. This native support was first íncluded within thé Android 4.0 (Ice Cream Sandwich) update, which ís first seen ón thé Galaxy Nexus smartphone. Previously, Android did not feature native support for screen capturing which would have likely been due tó security concerns. Furthermore, prior manufacturer ànd third-party customizations às well às using à PC connection (DDMS developer's tool) were thé ónly known methods óf capturing à screenshot ón Android. "
Android Uses.."While Google has their ówn line óf Android smartphones, thé Google Nexus series, thé ópen ànd customizable nature óf thé Android óperating system àllows ít tó be used ón most electronics, íncluding but not limited to: smartphones, laptops, netbooks, smartbooks, tablet computers, E-book readers, TVs (Google TV), wristwatches, headphones, Car CD ànd DVD players ànd óther devices.
The main hardware platform for Android ís thé ARM àrchitecture. There ís support for x86 from thé Android-x86 project, ànd Google TV uses à special x86 version óf Android.
The first commercially àvailable phone tó run Android was thé HTC Dream, released ón 22 óctober 2008. ín early 2010 Google collaborated with HTC tó launch íts flagship Android device, thé Nexus óne. This was followed later ín 2010 with thé Samsung-made Nexus S ànd ín 2011 with thé Galaxy Nexus.
iOS ànd Android 2.3.3 'Gingerbread' may be set up tó dual boot ón à jailbroken íPhone ór íPod Touch with thé help óf ópeniBoot ànd íDroid.
The Novó 7, manufactured by thé Chinese company àinol Electronics, was thé world's first Android 4.0 íce Cream Sandwich tablet."
Android Applications..Applications àre usually developed ín thé Java language using thé Android Software Development Kit, but óther development tools àre àvailable, íncluding à Native Development Kit for àpplications ór extensions ín C ór C++, Google àpp ínventor, à visual environment for novice programmers ànd various cross platform mobile web àpplications frameworks .
Android Market"Android Market ís thé ónline software store developed by Google for Android devices. àn àpplication program (""app"") called ""Market"" ís preinstalled ón most Android devices ànd àllows users tó browse ànd download àpps published by third-party developers, hosted ón Android Market. às óf óctober 2011 there were more than 300,000 àpps àvailable for Android, ànd thé estimated number óf àpplications downloaded from thé Android Market às óf December 2011 exceeded 10 billion. thé óperating system ítself ís ínstalled ón 130 million total devices.
Only devices that comply with Google's compatibility requirements àre àllowed tó preinstall Google's closed-source Android Market àpp ànd àccess thé Market. thé Market filters thé list óf àpplications presented by thé Market àpp tó those that àre compatible with thé user's device, ànd developers may restrict their àpplications tó particular carriers ór countries for business reasons.
Google has participated ín thé Android Market by óffering several àpplications themselves, íncluding Google Voice (for thé 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 ímage, Gesture Search (for using finger-written letters ànd numbers tó search thé contents óf thé phone), Google Translate, Google Shopper, Listen for podcasts ànd My Tracks, à jogging àpplication. ín àugust 2010, Google launched ""Voice àctions for Android"", which àllows users tó search, write messages, ànd ínitiate calls by voice.
Alternatively, users can ínstall àpps directly óntó thé device íf they have thé àpplication's àPK file ór from third party àpp stores such às thé àmazon àppstore."
Android Application security.."An example óf àpp permissions ín Android Market.
Android àpplications run ín à sandbox, àn ísolated àrea óf thé óperating system that does not have àccess tó thé rest óf thé system's resources, unless àccess permissions àre granted by thé user when thé àpplication ís ínstalled. Before ínstalling àn àpplication, Android Market displays àll required permissions. à game may need tó enable vibration, for example, but should not need tó read messages ór àccess thé phonebook. àfter reviewing these permissions, thé user can decide whether tó ínstall thé àpplication.
Some Android malware íncidents have been reported ínvolving rogue àpplications ón Android Market. ín àugust 2010, Kaspersky Lab reported detection óf thé first malicious program for Android, named Trojan-SMS.AndroidOS.FakePlayer.a, àn SMS trojan which had àlready ínfected à number óf devices. ín some cases àpplications which contained Trojans were hidden ín pirated versions óf legitimate àpps. Google has responded by removing malicious àpps from thé Android Market, ànd remotely disabling them ón ínfected devices.] Security firms such às àVG Technologies, àvast! ànd Symantec have released àntivirus software for Android devices."
Android Privacy.."Android smartphones have thé àbility tó report thé location óf Wi-Fi àccess points, encountered às phone users move àround, tó build vast databases containing thé physical locations óf hundreds óf millions óf such àccess points. These databases form electronic maps tó locate smartphones, àllowing them tó run àpps like Foursquare, Latitude, Places, ànd tó deliver location-based àds.
One design íssue ís that àverage users cannot monitor how àpplications àccess ànd use private ànd sensitive data (e.g. location ànd hardware íD numbers). Even during ínstallation, permission checks dó not óften índicate tó thé user how critical services ànd data will be used ór misused. Third party monitoring software such às TaintDroid, àn àcademic research-funded project, can ídentify personal ínformation sent from àpplications tó remote servers."
Android Marketing.."The Android logó was designed àlong with thé Droid font family made by àscender Corporation.
Android Green ís thé color óf thé Android Robot that represents thé Android óperating system. thé print color ís PMS 376C ànd thé RGB color value ín hexadecimal ís #A4C639, às specified by thé Android Brand Guidelines. thé custom typeface óf Android ís called Norad (cf. NORAD). ít ís ónly used ín thé text logo."
Android Market share.."Research company Canalys estimated ín Q2 2009 that Android had à 2.8% share óf worldwide smartphone shipments. By Q4 2010 this had grown tó 33% óf thé market, becoming thé top-selling smartphone platform. This estimate íncludes thé Tapas ànd óMS variants óf Android. By Q3 2011 Gartner estimates more than half (52.5%) óf thé smartphone market belongs tó Android.
In February 2010 ComScore said thé Android platform had 9.0% óf thé U.S. smartphone market, às measured by current mobile subscribers. This figure was up from àn earlier estimate óf 5.2% ín November 2009. By thé end óf Q3 2010 Android's U.S. market share had grown tó 21.4%.
In May 2010, Android's first quarter U.S. sales surpassed that óf thé rival íPhone platform. àccording tó à report by thé NPD group, Android àchieved 25% smartphone sales ín thé US market, up 8% from thé December quarter. ín thé second quarter, àpple's íOS was up by 11%, índicating that Android ís taking market share mainly from RIM, ànd still has tó compete with heavy consumer demand for new competitor ófferings. Furthermore, ànalysts pointed tó àdvantages that Android has às à multi-channel, multi-carrier óS, which àllowed ít tó duplicate thé quick success óf Microsoft's Windows Mobile. ín Q4 2010 Android had 59% óf thé total ínstalled user base óf àpple's íOS ín thé U.S. ànd 46% óf thé total ínstalled user base óf íOS ín Europe.
As óf June 2011, Google said that 550,000 new Android devices were being àctivated every day— up from 400,000 per day à month earlier — ànd more than 100 million devices had been àctivated. Android hit 300,000 àctivations per day back ín December 2010. By July 14, 2011, 550,000 Android devices were being àctivated by Google each day, with 4.4% growth per week. ón thé 1st óf àugust 2011, Canalys estimated that Android had àbout 48% óf thé smartphone market share. ón óctober 13, 2011, Google ànnounced that there were 190 million Android devices ín thé market. às óf November 16, 2011, during thé Google Music ànnouncement ""These Gó tó Eleven"", 200 million Android devices had been àctivated. Based ón this number, with 1.9% óf Android devices being tablets, àpproximately 3.8 million Android Honeycomb Tablets have been sold. ón December 20, 2011. àndy Rubin ànnounced that Google was àctivating 700,000 new Android devices daily."
Android Retail Stores..The carrier Telstra ópened thé world's first Android store, Androidland, ón Bourke Street, Melbourne ín December 2011.
Android Trademarks.."In órder tó use thé Android trademark, device manufacturers must ensure that thé device complies with thé Compatibility Definition Document (CDD) ànd then get permission from Google. Devices must àlsó meet this definition tó be eligible tó license Google's closed-source àpplications, íncluding thé Android Market. Participation ín thé compatibility program ís free óf charge.
In September 2010, Skyhook Wireless filed à lawsuit àgainst Google ín which they àlleged that Google had used thé compatibility document tó block Skyhook's mobile positioning service (XPS) from Motorola's Android mobile devices. ín December 2010 à judge denied Skyhook's motion for preliminary ínjunction, saying that Google had not closed óff thé possibility óf àccepting à revised version óf Skyhook's XPS service, ànd that Motorola had terminated their contract with Skyhook because Skyhook wanted tó disable Google's location data collection functions ón Motorola's devices, which would have violated Motorola's óbligations tó Google ànd íts carriers."
Android Licensing"The source code for Android ís àvailable under free ànd ópen source software licenses. Google published their Linux kernel changes under thé GNU General Public License version 2, ànd thé rest óf thé code (including network ànd telephony stacks) under thé àpache License version 2.0. Google àlsó keeps thé reviewed íssues list publicly ópen for ànyone tó see ànd comment.
The ópen Handset àlliance develops thé GPL-licensed part óf Android, that ís their changes tó thé Linux kernel, ín public, with source code publicly àvailable àt àll times. thé rest óf Android ís developed ín private, with source code released publicly when à major new version ís released. Typically Google collaborates with à hardware manufacturer tó produce à flagship device (part óf thé Google Nexus series) featuring thé new version óf Android, then makes thé source code àvailable àfter that device has been released.
In early 2011, Google chose tó temporarily withhold thé Android source code tó thé tablet-only Honeycomb release, creating doubts óver Google's commitment tó ópen source with Android. thé reason, àccording tó àndy Rubin ín àn ófficial Android blog post, was because Honeycomb was rushed for production óf thé Motorola Xoom, ànd they did not want third parties creating à ""really bad user experience"" by àttempting tó put óntó smartphones à version óf Android íntended for tablets. thé source code was ónce àgain made àvailable ín November 2011 with thé release óf Android 4.0."
Android Patents.. "Both Android ànd Android phone manufacturers have been thé target óf numerous patent lawsuits. ón 12 àugust 2010, óracle sued Google óver claimed ínfringement óf copyrights ànd patents related tó thé Java programming language. Specifically, thé patent ínfringement claim references seven United States patents íncluding US 5966702 ""Method ànd àpparatus for pre-processing ànd packaging class files"", ànd US 6910205 ""Interpreting functions utilizing à hybrid óf virtual ànd native machine ínstructions"".
In response, Google submitted multiple lines óf defense, counterclaiming that Android did not ínfringe ón óracle's patents ór copyright, that óracle's patents were ínvalid, ànd several óther defenses. They said that Android ís based ón àpache Harmony, à clean room ímplementation óf thé Java class libraries, ànd àn índependently developed virtual machine called Dalvik.
Microsoft has àlsó sued several manufacturers óf Android devices for patent ínfringement, ànd collects patent licensing fees from óthers. ín óctober 2011 Microsoft said they had signed license àgreements with ten Android device manufacturers, àccounting for 55% óf worldwide revenue for Android devices. These ínclude Samsung ànd HTC.
Google has publicly expressed íts dislike for thé current patent landscape ín thé United States, àccusing àpple, óracle ànd Microsoft óf trying tó take down Android through patent litigation, rather than ínnovating ànd competing with better products ànd services. ín àugust 2011, Google started thé process óf purchasing Motorola Mobility for US$12.5 billion, which was viewed ín part às à defensive measure tó protect Android, since Motorola Mobility holds more than 17,000 patents."
