Download android os

Seminar Report
On
ANDROID OS
Submitted in Partial Fulfillment of the Requirement for the
Award of the Degree
BACHELOR OF COMPUTER APPLICATIONS
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CONTENTS
1. Introduction
2. Architecture
2.1 Android Runtime
2.2 Linux Kernal
2.3 Libraries
2.4 Application Framework
2.5application Layer
3. Birth Of Android
4. Features
5. Advantages
6. Disadvantages
7. Applications
8. Uses
9. Conclusion And Future Scope
10. Referrences
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INTRODUCTION
Android is a software stack for mobile devices that
includes an operating system, middleware and key applications.
Android is a software platform and operating system for mobile
devices based on the Linux operating system and developed by
Google and the Open Handset Alliance. It allows developers to write
managed code in a Java-like language that utilizes Google-developed
Java libraries, but does not support programs developed in native
code. The unveiling of the Android platform on 5 Novembe r 2007
was announced with t h e f o u n d i n g o f t h e o p e n H a n d s e t
A l l i a n c e , a c o n s o r t i u m o f 3 4 hardware, software and telecom
companies devoted to advancing open standards for m o b i l e
devices. When released in 2008, most of the Android
p l a t f o r m w i l l b e m a d e available under the Apache free-software
and open-source license.
Android is a Linux-based operating system for mobile devices such as
smart phones and tablet computers. Android has a large community of
developers writing applications ("apps") that extend the functionality of the
devices. Developers write primarily in a customized version of Java. Apps can
be downloaded from third-party sites or through online stores such as Android
Market, the app store run by Google. As of October 2011 there were more than
400,000 apps available for Android, and the estimated number of applications
downloaded from the Android Market as of December 2011 exceeded 10
billion.
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The Open Handset Alliance, a consortium of several companies
which include Google, H T C , i n t e l , M o t o r o l a , Q u a l c o m m ,
T - M o b i l e , S p r i n t N e x t e l a n d NVIDIA, was unveiled with
t h e g o a l t o d e v e l o p o p e n s t a n d a r d s f o r m o b i l e d e v i c e s . Along
with the formation of the Open Handset Alliance, the OHA also unveiled their
first product, Android, an open source mobile device platform based
on the Linux operating system.
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ARCHITECTURE
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2.1 ANDROID RUNTIME
At the same level there is Android Runtime, where the
main component Dalvik Virtual Machine is located. It was designed
specifically for Android r u n n i n g i n l i m i t e d e n v i r o n m e n t , w h e r e
the limited battery, CPU, memory and data storage are the
main issues. Android gives an integrated tool “dx”, which
converts generated byte code from .jar to .dex file, after this
b y t e c o d e b e c o m e s m u c h m o r e efficient to run on the small
processors.
2.2 LINUX KERNAL
Android relies on Linux version 2.6 for core system
s e r v i c e s s u c h a s security, memory management, process
management, network stack, and driver model. The kernel also acts
as an abstraction layer between the hardware and the rest of the
software stack. It helps to manage security, memory management,
process management, network stack and other important issues. Therefore,
the user should bring L i n u x i n h i s m o b i l e d e v i c e a s t h e m a i n
o p e r a t i n g s y s t e m a n d i n s t a l l a l l t h e d r i v e r s required in order to
run it.
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2.3 LIBRARIES
In the next level there are a set of native libraries written
in C/C++,w h i c h a r e r e s p o n s i b l e f o r s t a b l e p e r f o r m a n c e o f
various components. Moreover, it is possible to use 2D and
3D graphics in the same application in Android. The media
framework was provided by Packet Video, one of the members of OHA. It
gives libraries f o r a p l a y b a c k a n d r e c o r d i n g s u p p o r t f o r a l l t h e
m a j o r m e d i a a n d s t a t i c i m a g e f i l e s . Free Type libraries are used
to render all the bitmap and vector fonts. For data storage, Android
uses SQLite. As mentioned before, it is extra light rational management
system, w h i c h l o c a t e s a s i n g l e f i l e f o r a l l o p e r a t i o n s r e l a t e d t o
d a t a b a s e . W e b K i t , t h e s a m e browser used by Apples’Safari, was
modified by Android inorder to fit better in a small size screen.
2.4 APPLICATION FRAMEWORK
After that, there is Application Framework, written in Java
language. It is a tool kit that all applications use, ones which come
with mobile device like Contacts or SMS box, or applications
written by Google and any Android developer. It has several
components. The Activity Manager manages the life circle of the applications
and provides a c o m m o n n a v i g a t i o n b a c k s t a c k f o r
a p p l i c a t i o n s , w h i c h a r e r u n n i n g i n d i f f e r e n t processes.
The Package Manager keeps track of the applications, which are
installed in the device. The Windows Manager is Java programming
language abstraction on the top of lower level services that are provided by the
Surface Manager.
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The Telephony Manager contains of a set of API
necessary for calling a p p l i c a t i o n s . C o n t e n t P r o v i d e r s w a s
built for Android to share a data with other
a p p l i c a t i o n s , for instance, the contacts of people in the address book can
be used in other applications too. The Resource Manager is used to store
localized strings, bitmaps, lay out file descriptions and other external parts of
the application. The View System generates a set of buttons and lists used in
UI. Other components like Notification manager is used to customized is play
alerts and other functions.
2.5 APPLICATION LAYER
At the top of Android Architecture we have all the
applications, which are used by the final user. By installing different
applications, the user can turn his mobile phone into the unique,
optimized and smart mobile phone. All applications are written using
the Java programming language.
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BIRTH OF ANDROID
Google Acquires Android Inc.
In July 2005, Google acquired Android Inc., a small startup
company based in Palo Alto, CA. Android's co-founders who went to work at
Google included Andy Rubin (co-founder of Danger), Rich Miner (co-founder
of Wildfire Communications, Inc), Nick Sears (once VP at T-Mobile), and
Chris White (one of the first engineers at WebTV). At the time, little was
known about the functions of Android Inc. other than they made software for
mobilephones.
At Google, the team, led by Rubin, developed a Linux-based mobile
device OS which they marketed to handset makers and carriers on the premise
of providing a flexible, upgradeable system. It was reported that Google had
already lined up a series of hardware component and software partners and
signaled to carriers that it was open to various degrees of cooperation on their
part.
Open Handset Alliance Founded
On 5 November 2007, the Open Handset Alliance, a consortium
of several companies which include Google, HTC, Intel, Motorola,
Qualcomm, T-Mobile, Sprint Nextel and NVIDIA, was unveiled with the goal
to develop open standards for mobile devices. Along with the formation of the
Open Handset Alliance, the OHA also unveiled their first product, Android, an
open source mobile device platform based on the Linux operating system.
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Hardware
Google has unveiled at least three prototypes for Android, at the
Mobile World Congress on February 12, 2008. One prototype at the ARM
booth displayed several basic Googleapplications. A 'd-pad' control zooming
of items in the dock with a relatively quick response.
A prototype at the Google IO conference on May 28, 2008 had a
528 MHz Qualcomm processor and a Synaptics capacitive touch screen, and
used the UMTS cellular standard. It had 128 MB of RAM and 256 MB of
flash, showing that Android's memory requirements are reasonable. The demo
was carried out using a 3.6 Mbit/s HSDPA connection.
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FEATURES
 Storage - SQLite, a lightweight relational database, is used for data
storage purposes.
 Connectivity- Android supports connectivity technologies including
GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE,
NFC and WiMAX.
 Messaging- SMS and MMS are available forms of messaging,
including threaded text messaging and now Android Cloud To Device
Messaging (C2DM) is also a part of Android Push Messaging service.
 Multiple language support- Android supports multiple languages.
 Web browser- The web browser available in Android is based on
the open-source WebKit layout engine, coupled with Chrome's V8
JavaScript engine. The browser scores 100/100 on the Acid3 test on
Android 4.0.
 Java support- While most Android applications are written in Java,
there is no Java Virtual Machine in the platform and Java byte code is
not executed. Java classes are compiled into Dalvik executables and
run on Dalvik, a specialized virtual machine designed specifically for
Android and optimized for battery-powered mobile devices with
limited memory and CPU. J2ME support can be provided via thirdparty applications.
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 Media support- Android supports the following audio/video/still
media formats: WebM, H.263, H.264 (in 3GP or MP4 container),
MPEG-4 SP, AMR, AMR-WB (in 3GP container), AAC, HE-AAC (in
MP4 or 3GP container), MP3, MIDI, Ogg Vorbis, FLAC, WAV,
JPEG, PNG, GIF, BMP.
 Bluetooth- Supports A2DP, AVRCP, sending files (OPP), accessing
the phone book (PBAP), voice dialing and sending contacts between
phones. Keyboard, mouse and joystick (HID) support is available in
Android 3.1+, and in earlier versions through manufacturer
customizations and third-party applications.
 Video calling- Android does not support native video calling, but
some handsets have a customized version of the operating system that
supports it, either via the UMTS network (like the Samsung Galaxy S)
or over IP. Video calling through Google Talk is available in Android
2.3.4 and later. Gingerbread allows Nexus S to place Internet calls with
a SIP account. This allows for enhanced VoIP dialing to other SIP
accounts and even phone numbers. Skype 2.1 offers video calling in
Android 2.3, including front camera support.
 Multitasking- Multitasking of applications is available.
 Multi-touch- Android has native support for multi-touch which was
initially made available in handsets such as the HTC Hero. The feature
was originally disabled at the kernel level (possibly to avoid infringing
Apple's patents on touch-screen technology at the time). Google has
since released an update for the Nexus One and the Motorola Droid
which enables multi-touch natively.
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ADVANTAGES
Open
- Android allows you to access core mobile device functionality
through standard API calls.
All applications are equal
- Android does not differentiate between
the phone's basic and third-party applications -- even the dialer or
home screen can be replaced.
Breaking down boundaries
- Combine information from the web
with data on the phone -- such as contacts or geographic location -- to
create new user experiences.
Fast and easy development
- The SDK contains what you need to
build and run Android applications, including a true device emulator
and advanced debugging tools.
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DISADVANTAGES
Security - Making source code available to everyone inevitably invites the
attention of black hat hackers.
Open Source
- A disadvantage of open-source development is
that anyonecanscrutinizethesourcecodetofindvulnerabilitiesandwriteexploits.
Login
- Platform doesn't run on an encrypted file system and has a
vulnerablelog-in.
Incompetence
- Google’s dependence on hardware and carrier
partners puts the final product out of their control.
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APPLICATIONS
Applications are usually developed in the Java language using
the Android Software Development Kit, but other development tools are
available, including a Native Development Kit for applications or extensions
in C or C++, Google App Inventor, a visual environment for novice
programmers and various cross platform mobile web applications frameworks
.
Android Market
The Android Market on a phone
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Android Market is the online software store developed by
Google for Android devices. An application program ("app") called "Market"
is preinstalled on most Android devices and allows users to browse and
download apps published by third-party developers, hosted on Android
Market.
As of October 2011 there were more than 300,000 apps
available for Android, and the estimated number of applications downloaded
from the Android Market as of December 2011 exceeded 10 billion. The
operating system itself is installed on 130 million total devices.
Only devices that comply with Google's compatibility
requirements are allowed to preinstall Google's closed-source Android Market
app and access the Market. The Market filters the list of applications presented
by the Market app to those that are compatible with the user's device, and
developers may restrict their applications to particular carriers or countries for
business reasons.
Google has participated in the Android Market by offering
several applications themselves, including Google Voice (for the Google
Voice service), Sky Map (for watching stars), Finance (for their finance
service), Maps Editor (for their MyMaps service), Places Directory (for their
Local Search), Google Goggles that searches by image, Gesture Search (for
using finger-written letters and numbers to search the contents of the phone),
Google Translate, Google Shopper, Listen for podcasts and My Tracks, a
jogging application. In August 2010, Google launched "Voice Actions for
Android", which allows users to search, write messages, and initiate calls by
voice.
Alternatively, users can install apps directly onto the device if
they have the application's APK file or from third party app stores such as the
Amazon Appstore.
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Application security
An example of app permissions in Android Market.
Android applications run in a sandbox, an isolated area of the
operating system that does not have access to the rest of the system's
resources, unless access permissions are granted by the user when the
application is installed. Before installing an application, Android Market
displays all required permissions. A game may need to enable vibration, for
example, but should not need to read messages or access the phonebook. After
reviewing these permissions, the user can decide whether to install the
application.
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Some Android malware incidents have been reported
involving rogue applications on Android Market. In August 2010, Kaspersky
Lab reported detection of the first malicious program for Android, named
Trojan-SMS. Android OS Fake Player a, an SMS trojan which had already
infected a number of devices. In some cases applications which contained
Trojans were hidden in pirated versions of legitimate apps. Google has
responded by removing malicious apps from the Android Market, and
remotely disabling them on infected devices. Several security firms have
released antivirus software for Android devices, in particular, AVG
Technologies, Avast!, F-Secure, Kaspersky, McAfee and Symantec.
Privacy
Android smartphones have the ability to report the location of
Wi-Fi access points, encountered as phone users move around, to build vast
databases containing the physical locations of hundreds of millions of such
access points. These databases form electronic maps to locate smartphones,
allowing them to run apps like Foursquare, Latitude, Places, and to deliver
location-based ads.
Third party monitoring software such as TaintDroid, an
academic research-funded project, can, in some cases, detect when personal
information is being sent from applications to remote servers.
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SECURITY ISSUES
Android mobile phone platform is going to be more secure
than Apple, iPhone or any other device in the long run. There are several
solutions nowadays to protect Google phone from various attacks. One of them
is security vendor McAfee, a member of Linux Mobile (LiMo) Foundation.
This foundation joins particular companies to develop an open mobile-device
software platform. Many of the companies listed in the LiMo Foundation have
also become members of the Open Handset Alliance (OHA).
As a result, Linux secure coding practice should successfully be
built into the Android development process. However, open platform has its
own disadvantages, such as source code vulnerability for black-hat hackers. In
parallel with great opportunities for mobile application developers, there is an
expectation for exploitation and harm. Stealthy Trojans hidden in animated
images, particular viruses passed from friend to friend, used for spying and
identity theft, all these threats will be active for a long run.
Another solution for such attacks is SMobile Systems mobile
package. SecurityShield “an integrated application that includes anti-virus,
anti-spam, firewall and other mobile protection is up and ready to run on the
Android operating system. Currently, the main problem is availability for
viruses to pose as an application and do things like dial phone numbers, send
text messages or multi-media messages or make connections to the Internet
during normal device use. It is possible for somebody to use the GPS feature to
track a personâ„¢s location without their knowledge. Hence SMobile Systems
is ready to notify and block these secure alerts. But the truth is that it is not
possible to secure your mobile device or personal computer completely, as it
connects to the internet. And neither the Android phone nor other devices will
prove to be the exception.
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USES
Galaxy Nexus, the latest "Google phone"
I'm Watch, a wristwatch with phone functionality, running a custom version of
Android.
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Google TV Home Screen
While Google has their own line of Android smartphones, the
Google Nexus series, the open and customizable nature of the Android
operating system allows it to be used on most electronics, including but not
limited to: smartphones, fixed phones, laptops, netbooks, smartbooks, tablet
computers, E-book readers, TVs (Google TV), wristwatches, headphones, Car
CD and DVD players, digital cameras, Portable media players and other
devices.
The main hardware platform for Android is the ARM
architecture. There is support for x86 from the Android x86 project, and
Google TV uses a special x86 version of Android.
The first commercially available phone to run Android was the
HTC Dream, released on 22 October 2008. In early 2010 Google collaborated
with HTC to launch its flagship Android device, the Nexus One. This was
followed later in 2010 with the Samsung-made Nexus S and in 2011 with the
Galaxy Nexus.
iOS and Android 2.3.3 'Gingerbread' may be set up to dual boot
on a jailbroken iPhone or iPod Touch with the help of OpeniBoot and iDroid.
The NOVO7, manufactured by the Chinese company Ainol
Electronics, was the world's first Android 4.0 Ice Cream Sandwich tablet.
In December 2011 it was announced the Pentagon has officiall
approved Android for use by its personnel.
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CONCLUSION AND FUTURE SCOPE
Android has been criticized for not being all open-source
software despite what was announced by Google. Parts of the SDK are
proprietary and closed source, and some believe this is so that Google can
control the platform. Software installed by end -users m u s t b e
written in Java, and will not have access to lower level
d e v i c e A P I s . T h i s provides end-users with less control over their
phone's functionality than other free and open source phone platforms,
such as OpenMoko.
With all upcoming applications and mobile services Google
Android is s t e p p i n g i n t o t h e n e x t l e v e l o f M o b i l e I n t e r n e t .
A n d r o i d p a r t i c i p a t e s i n m a n y o f t h e successful open source
projects. That is, architect the solution for participation and the
developers will not only come but will play well together. This is
notable contrast with Apple and other companies, where such
architecture of participation is clearly belated. The first Android based
official devices may well be launched sometime in the early half of 2009.
Obviously, that's an age away when it comes to handset design, and
Android may well find itself competing against the forthcoming
Nokia touch screen phones and may be even the iPhone.
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REFERRENCES
1.http://www.android.comAndroidOfficialWebpage
2.http://code.google.com/android/-OfficialAndroidGoogleCodeWebpage
3.http://www.openhandsetalliance.com/-OpenHandsetAllianceWebpage
4.http://www.androidwiki.com–AndroidWiki
5.http://googleblog.blogspot.com/-OfficialGoogleBlog
6.http://en.wikipedia.org/wiki/Android_(mo...–WikipediaInformation
7.http://en.wikipedia.org/wiki/SQLite
8.http://en.wikipedia.org/wiki/WebKit
9.http://en.wikipedia.org/wiki/Eclipse_(software)
10.http://www.itworld.com/google-android-dr-080213
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