AnDroID OS

Android (operating system)

From Wikipedia, the free encyclopedia

Android

Android 4.4.2 home screen
Company / developer	Google Open Handset Alliance
Written in	C (core), C++, Java (UI)[1]
OS family	Unix-like
Working state	Current
Source model	Open source[2] and in most devices with proprietary components[3]
Initial release	September 23, 2008[4]
Latest release	4.4.2 KitKat / December 9, 2013; 4 months ago[5]
Marketing target	Smartphones Tablet computers
Available in	Multi-lingual (46 languages)
Package manager	Google Play, APK
Supported platforms	32-bit ARM, MIPS,[6] x86[7]
Kernel type	Monolithic (modified Linux kernel)
Userland	Bionic libc,[8] mksh shell,[9] native core utilities with a few from NetBSD[10]
Default user interface	Graphical (Multi-touch)
License	Apache License 2.0 Modified Linux kernel under GNU GPL v2[11]
Official website	www.android.com

Android is an operating system based on the Linux kernel, and designed primarily for touchscreen mobile devices such as smartphones and tablet computers. Initially developed by Android, Inc., which Google backed financially and later bought in 2005,^[12] Android was unveiled in 2007 along with the founding of the Open Handset Alliance—​a consortium of hardware, software, and telecommunication companies devoted to advancing open standards for mobile devices.^[13] The first publicly available smartphone running Android, the HTC Dream, was released on October 22, 2008.^[14]
The user interface of Android is based on direct manipulation, using touch inputs that loosely correspond to real-world actions, like swiping, tapping, pinching, and reverse pinching to manipulate on-screen objects. Internal hardware—​such as accelerometers, gyroscopes, and proximity sensors— ​is used by some applications to respond to additional user actions, for example adjusting the screen from portrait to landscape depending on how the device is oriented. Android allows users to customize their home screens with shortcuts to applications and widgets, which allow users to display live content, such as emails and weather information, directly on the home screen. Applications can further send notifications to the user to inform them of relevant information, such as new emails and text messages. Despite being primarily designed for phones and tablets, it also has been used in televisions, games consoles, digital cameras, and other electronics.
Android is the most popular mobile OS and as of 2013, its devices also sell more than Windows, iOS and Mac OS devices combined.^[15][16][17] In the third quarter of 2013, Android's share of the global smartphone shipment market was 81.3%, the highest ever.^[18] As of July 2013 the Google Play store has had over 1 million Android apps published, and over 50 billion apps downloaded.^[19] A developer survey conducted in April–May 2013 found that Android is used by 71% of mobile developers.^[20] The operating system's success has made it a target for patent litigation as part of the so-called "smartphone wars" between technology companies.^[21][22] As of September 2013, one billion Android devices have been activated.^[23]
Android's source code is released by Google under open source licenses, although most Android devices ultimately ship with a combination of open source and proprietary software.^[3] Android is popular with technology companies which require a ready-made, low-cost and customizable operating system for high-tech devices.^[24] Android's open nature has encouraged a large community of developers and enthusiasts to use the open-source code as a foundation for community-driven projects, which add new features for advanced users^[25] or bring Android to devices which were officially released running other operating systems.

History

Android, Inc. was founded in Palo Alto, California in October 2003 by Andy Rubin (co-founder of Danger),^[26] Rich Miner (co-founder of Wildfire Communications, Inc.),^[27] Nick Sears^[28] (once VP at T-Mobile), and Chris White (headed design and interface development at WebTV)^[12] to develop, in Rubin's words "smarter mobile devices that are more aware of its owner's location and preferences".^[12] The early intentions of the company were to develop an advanced operating system for digital cameras, when it was realised that the market for the devices was not large enough, and diverted their efforts to producing a smartphone operating system to rival those of Symbian and Windows Mobile.^[29] Despite the past accomplishments of the founders and early employees, Android Inc. operated secretly, revealing only that it was working on software for mobile phones.^[12] That same year, Rubin ran out of money. Steve Perlman, a close friend of Rubin, brought him $10,000 in cash in an envelope and refused a stake in the company.^[30]
Google acquired Android Inc. on August 17, 2005; key employees of Android Inc., including Rubin, Miner, and White, stayed at the company after the acquisition.^[12] Not much was known about Android Inc. at the time, but many assumed that Google was planning to enter the mobile phone market with this move.^[12] At Google, the team led by Rubin developed a mobile device platform powered by the Linux kernel. Google marketed the platform to handset makers and carriers on the promise of providing a flexible, upgradable system. Google had 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.^[31][32][33]
Speculation about Google's intention to enter the mobile communications market continued to build through December 2006.^[34] The unveiling of the iPhone, a touchscreen-based phone by Apple, on January 9, 2007 had a disruptive effect on the development of Android. At the time, a prototype device codenamed "Sooner" had a closer resemblance to a BlackBerry phone, with no touchscreen, and a physical, QWERTY keyboard. Work immediately began on re-engineering the OS and its prototypes to combine traits of their own designs with an overall experience designed to compete with the iPhone.^[35][36] In September 2007, InformationWeek covered an Evalueserve study reporting that Google had filed several patent applications in the area of mobile telephony.^[37][38]

Eric Schmidt, Andy Rubin and Hugo Barra at a press conference for the Google's Nexus 7 tablet.

On November 5, 2007, the Open Handset Alliance, a consortium of technology companies including Google, device manufacturers such as HTC, Sony and Samsung, wireless carriers such as Sprint Nextel and T-Mobile, and chipset makers such as Qualcomm and Texas Instruments, unveiled itself, with a goal to develop open standards for mobile devices.^[13] That day, Android was unveiled as its first product, a mobile device platform built on the Linux kernel version 2.6.25.^[13][39] The first commercially available smartphone running Android was the HTC Dream, released on October 22, 2008.^[14]
In 2010, Google launched its Nexus series of devices – a line of smartphones and tablets running Android operating system, and built by a manufacturing partner. HTC collaborated with Google to release the first Nexus smartphone,^[40] the Nexus One. The series has since been updated with newer devices, such as the Nexus 5 phone and Nexus 7 tablet, made by LG and Asus respectively. Google releases the Nexus phones and tablets to act as their flagship Android devices, demonstrating Android's latest software and hardware features. On March 13, 2013, it was announced by Larry Page in a blog post that Andy Rubin had moved from the Android division to take on new projects at Google.^[41] He was replaced by Sundar Pichai, who also continues his role as the head of Google's Chrome division,^[42] which develops Chrome OS.

How to Permanently Delete a Facebook Account

Steps

1. Save any data you need. Before you delete your account, save any photos and contact information you need from your account. You will lose access to all of this when you delete your account.
   • You can download a copy of all of your Facebook data through the Account Settings. Click on the Gear icon in the upper-right corner to access it. Click the link that says “Download a copy of your Facebook data”.
     
     
2. Clear your Facebook history. You can open the Activity Log to undo all of your previous actions on Facebook, such as liking posts and comments you’ve made. This will help ensure that as little data about you remains as possible after your account is deleted.
   • To access the Activity Log, click the Privacy button in the top-right corner. Select “Who can see my stuff?” Click the link for the Activity Log. Here you can choose which parts of your activity you would like to delete.
     
     
3. Visit the Delete Account page. This page cannot be accessed through Facebook unless you search for it. You can also follow this link. Click the “Delete my Account” button to start the account deletion process.^[1]
4. Enter your password and the CAPTCHA. Once you have entered these, press “Okay” to permanently delete your account. You will need to wait 14 days for the deletion to take effect.
   • You need to have access to your Facebook account in order to delete it this way. If you can’t remember your password, use Facebook’s password reset service before deleting your
5. Try a temporary deactivation instead of deleting your account.
   • Click the Settings icon and select Account Settings.
     
     
   • Open the Security section from the left menu.
     
     
   • Click the “Deactivate your account” link
     
     
   • Fill out the form for deactivating your account. You will still be able to be linked in posts and messaged, though you will not receive notifications about it.
     
     

Tips

• Download and back up any photos or other information you want to save before deleting your account. To find the "download" option go to "General Account Settings">"Download a copy". This will allow you to download a copy of your data directly from Facebook.

10 Fascinating Facts about :: INTEL ::::::

10 Fascinating Facts INTEL 

• 

  1. How Intel Got Its Name

  Intel was founded in 1968 by two ex-Fairchild Semiconductor employees, Gordon E. Moore and Robert N. Noyce.

  The company was originally called "N M Electronics." Legend has it, their preferred name — "Moore Noyce Electronics" — sounded too similar to "more noise," not a great brand message in that industry.

  "Integrated Electronics" was considered as a possible name, but was taken, so the first syllables of each word were used instead.

  "Intel," described by Noyce as "sort of sexy," was eventually agreed upon. The pair then purchased the "Intel" trademark from the Intelco hotel chain for just $15,000.

  Image courtesy of Flickr, keitamiyoshi

• 

  2. Intel Once Made Watches

  In 1972, Intel moved into the jewelry market with the acquisition of digital watch maker Microma.

  At the time, digital watches were considered seriously high-tech, selling for hundreds of dollars, so the move was not a surprising one. The anticipated market for such high-tech timepieces was 200 million units.

  However, when competition saw watch prices drop to the $10 mark, Intel decided to apply its tech expertise to other areas, selling the Microma brand and assets in 1978.

  It's reported that Gordon Moore still wears his Microma watch, stating: "It is to remind me, if I ever find myself thinking of getting into other consumer products, of the trouble we'd be getting into."

  Image courtesy of Flickr, Marcin Wichary

• 

  3. Intel's BunnyPeople

  You may recall in 1997, Intel created a fun, iconic advert for the Super Bowl, which featured colorful, dancing Intel technicians in special suits.

  These were nicknamed (and in fact trademarked) "BunnyPeople." The characters frequently appeared in advertising campaigns for the Pentium microprocessor series from this date on.

  However, the origin of the "BunnyPeople" dates much further back to 1973, when the "bunny suit" became standard Intel cleanroom attire.

  Worn by Fab technicians, it was a dramatic change from the more relaxed procedures predating 1973.

  One Intel employee recalls the suits were such a novelty that people used to find excuses to visit the Fab labs just so they could put a bunny suit on.

  The bunny suit is now a part of Intel's company culture. One year it even made for a classic April Fool's joke: Employees were informed they would be able to choose from new designs, like "Camouflage Comfy," "Polka Dot Parka" or "Miss Kitty."

• 

  4. Intel's Customized Champagne Tradition

  As a company tradition, Intel has customized bottles of champagne made to celebrate special occasions and milestones.

  The tradition dates back to the company's early days, "when a circuit finally worked or a product was shipped for the first time, the news was announced over the paging system. Then, someone would break out the bubbly."

  One Intel employee recalls a time when so many corks were popped against the acoustic tile ceiling in the cafeteria that it had to be replaced.

  In 1973, when Intel hit its first $3 million month, the then director of marketing ordered bottles of "Domaine d'Intel."

  The Museum of Computing also houses bottles in its collection that celebrate a Fields Sales Force success and the first $250 million quarter.

  Image courtesy of Computer History Museum

• 

  5. The 8080 Intel Asteroid

  While Intel can claim many firsts, one of the most seminal was 1974's 8080 microprocessor, the first 8-bit true general purpose microprocessor, which soon became an industry standard.

  In 1987, the CERGA Observatory named a Caussols main belt asteroid "8080 Intel" in honor of the invention.

  Today, Intel's main Santa Clara phone number is (408) 765-8080, surely no coincidence.

  Image courtesy of Intel Italia

• 

  6. Intel's Cubicle Culture

  Once forward-thinking about the workplace, Intel is credited with helping to develop corporate America's "cubicle culture."

  "There are no closed doors at Intel. Shoulder-high cubicles separate employees — even top management — from one another so that communication lines are always open."

  However, as younger companies like Facebook, Twitter and Google made changes in workplace culture, Intel's offices were criticized for being a little dated.

  Conan O'Brien had tons of fun at Intel's expense during a visit to the company in 2007. After commenting on the grey-on-grey color scheme, O'Brien said of the cubicle farms, "This is good. It makes people feel that they are basically all the same, that there is no individuality, that there is no hope, there's no sense that life has possibilities."

  Soon after, Intel announced a $10 million workplace revamp to create an "environment that feels more comfortable and energized."

  Image courtesy of Flickr, Paulo Ordoveza

• 

  7. Intel's "Red X" Marketing Campaign

  Intel played a major part in making PCs consumer-approachable, asking both business customers and consumers to learn what's inside their PCs, per the infamous "Intel Inside" slogan.

  Before "Intel Inside," though, was the "Red X" campaign. Created by Intel marketing guru Dennis Carter, the commercials were controversial, not just for the graffiti graphics, or for targeting end-users, but for actively dissing an existing Intel product.

  Intel wanted to promote the 386 SX processor over the 286, so the company ran ads with a red "X" through the numbers 286, suggesting the 386 was a better option.

  Competitors soon caught on to this pioneering marketing, and Intel, assuming the "386" and subsequent "486" processors were protected trademarks, tried to block similar numerical names for processors from other brands.

  In 1991, this block was ruled out by the courts, so Dennis Carter came up with the now infamous "Intel Inside" slogan as a blanket alternative.

  Carter's work was a success. Alongside the likes of Coke, Disney and McDonald's, the Intel brand is now one of the top 10 known brands in the world.

  Image courtesy of Flickr, Intel Photos

• 

  8. Intel's Logo Evolution

  Intel has kept its corporate branding very tight over the years, with little change to its iconic logo.

  The original logo featured an unusual dropped "E," which was used for 37 years.

  In fact, Intel's dropped "E" logo was so familiar that Apple made a visual pun about it during Steve Jobs' 2005 WWDC keynote.

  After the announcement that Apple would make the switch to Intel processors, Jobs showed a slide that read "It's true!" The "E" in "true" was dropped to resemble Intel's branding.

  Soon after the "Intel Inside" design was introduced, it remained for 15 years until the creation of the current logo.

  Intel said, "With deep respect for the Intel heritage, the new logo embodies the Intel of the past, the present and into the future. Its dynamic forward motion captures Intel as a catalyst for positive change and as a driving force toward newer technological leaps."

• 

  9. Intel on the Endeavour

  In 1995 Intel announced some of its kit had been used in the "first ever real-time, PC-based personal conference from space."

  Astronauts on the Space Shuttle Endeavour used the ProShare Personal Conferencing software to share info with NASA flight coordinators at the Johnson Space Center in Houston, Texas.

  During the call, they "shared photographic images on the PC and annotated shared information with words and drawings," which must have been pretty impressive for 1995 technology.

  Image courtesy of Tinker Northwest

• 

  10. Intel's Infamous "Bong"

  Finally, the Intel "bong" is known as a sonic logo, or "sonic branding" exercise.

  The trademark five-note sound was created by Austrian-born composer Walter Werzowa in 2004. It is used heavily in the chip maker’s advertising and branding campaigns.

  The bong has been heard more than a billion times since. It is estimated the tune is played somewhere around the world every five minutes.

10 Best Tools For Photo Editing EASY TO USE

With modern cameras, digital photography can seem very easy with the basic models producing clear and crisp photos. However, there are some issues, such as white balance, lighting and red-eye among others that may not produce the image you’d desire. This is why it’s a good idea to have a photo editor which can help resolve such issues.
You’d also want your photos to stand out but don’t want to splurge money on some expensive software. If so, keep your worries away as there is no dearth of such free tools-both Web-based and installed software-which can do a lot of photo-editing besides enhancement without burning a hole in your pocket.
Check out this amazing collection of 10 best free photo editing software. Click on each link for getting the full details.

1. GIMP

GIMP is often regarded as the best alternative to Photoshop. It’s an open-source application that depends on a bunch of willing developers who are responsible for the maintenance and improvement of the product. The software is available for PC and Mac. With this tool, you can get editing done on the professional level besides some great re-touching tools. It’s ideal for designers who are incapable of splurging money on Adobe or even for those who don’t want higher expenses.

After starting the program, you’ll find a window that shows the image along with separate windows for proper organization of the layers and toolbox. GIMP resembles Photoshop in many ways-however, it has a unique feel and look.

2. Google’s Picasa

Google’s Picasa is a free software which is widely used. It has a thrilling effect with its smoothness and the way with which it allows you to import and regulate your digital images besides rendering them to perfection. It’s available for Linux, Macs and Windows.  Picasa is an excellent photo application, with the new version adding a host of creative new effects.

Its effects, geo-tagging, text overlay, face recognition and user-friendly options are all adorable. The continuation of Picasa by Google is thought by many to be a desktop application.

3. Photoscape

Photoscape is a free easy and fun photo editing software that allows you to fix your photos besides enhancing them. On digging deeper into this wonderful tool, you’ll soon realize why so many readers recommend photoscape as a photo editing software. It has plenty of features, yet is easy to use.

The software provides various modules like editor, viewer, Raw converter, batch processor, print layout tool, file renamer, color picker and screen capture tool among others. The program is restricted to working with a single document at a time. Hence, if you want to change an image on which you are working, you’ll have to save the current file and close it.

4. Light Box Image Editor

LightBox free image editor is a powerful and simple editor used to enhance your images and make them look outstanding with some professional touch. It has an appealing user interface which is straight forward and simple. It also offers perceptive slide-bar attunements for the images.

Make a comparison of your pictures before and after the corrections with split screen views. The software has simple tools for correction of red-eye, crop, sharpen, print, add borders and re-size. You can also move to the paid version if you want where you can get some very handy extras.

5. Paint.Net

Paint.Net is a pixel-based image editor which can be used on PCs running Windows. It has become a very powerful application and offers a wide range of features and tools for enhancement of your images along with creative editing. It’s powerful with respect to image editing basics and has options to rotate or resize your photos besides some special effects.

Paint.Net, however, does not have adjustment layers nor any feature of native layer mask. This indicates that you won’t find easy options for editing that is non-destructive.

6. Serif Photo Plus

Serif Photo Plus was created by Serif as a free version from its premium software suite so that users could have access to fundamental tools for editing their photos. All the basics of image editing have been covered by this software. It has tools that allow you resize, cut down red-eye and apply filters and effects. However, since it lacks some essential features of the premium version, it has some amount of restrictions-the first one being a dearth of keyboard shortcuts.

Nonetheless, Serif Photo Plus can be used by anyone wanting to make his image standout. It’s ideal for graphic design jobs and has an intuitive interface.

7. iPhoto ’11

The new iPhoto ’11 appears pretty amazing-which is something great for photographers wanting to make the most out of their pictures. It allows you to do some great things with the aid of those pixels. With iPhoto’11, you can import, arrange, enhance and produce classy output from your digital images.

The software allows you to browse albums, events, projects, places and faces. It shares albums and photos easily to Flickr and Facebook, even though you don’t get galleries hosted by Apple.

8. LazPaint

LazPaint is a free and open-source raster image editor targeted at users who want a relatively easily accessible application compared to GIMP. The latter may offer a wide range of strong features but is associated with a steep learning curve which is often a hindrance for inexperienced users.  This indicates there are people who want a less powerful but a user-friendly application and LazPaint does exactly this.

The application is at present offered for Linux and Windows machine. It is, however, not a strong tool for image enhancement and adjustment.

9. Phoxo

Phoxo is a free and robust image editing software, which is tiny, speedy, user-friendly and can be described as a mini Photoshop. Some essential features of this software include undo, layers, batch processing and around 50 special effects. It also has handy and strong tools for crop, selecting, painting, navigation, measuring and retouching. Text effects can be easily added to images like ripple text, shadow text and gradient color text.

10. Funny Photo Maker

With Funny Photo Maker , you can have your face attached to the body of a celebrity or combine with attractive natural sceneries. You can also get your family picture on a photo calendar or photo billboard.  It does not have smart selection tools or layer support but still you can achieve a scintillating range of effects.

Some options of this free software include transforming still images into animations, adding snow or rain to an image, applying some elegant frames and transforming your images into a collage.

click on software name for download >>>>>>>

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Simple Way to Repair your Corrupted Pen drive /Memory card/USB

Scanning for Problems (Windows)

1. 
   1
   Insert the drive into the USB port on the computer.
2. 
   2
   Open My Computer and right click on the Removable Disk Icon. Choose the Properties option.
   
   
3. 
   3
   Click on the Tools tab.
   
   
4. 
   4
   Click on the Check Now button.
   
   
5. 5
   
   Click on both “Automatically fix file system errors” and “Scan for and attempt recovery of bad sectors” check boxes. Click Start.
   
   
6. 
   6
   Wait for the scan to complete. Click Close when finished.
   
   

Method 3 of 3: Reformatting the Drive

1. 
   1
   Format with NTFS instead of FAT32.
2. 
   2
   After this, format again with FAT32.

OSI model and Layers Complete Description

Definition: The OSI model defines inter networking in terms of a vertical stack of seven layers. Upper layers of the OSI model represent software that implements network services like encryption and connection management. Lower layers of the OSI model implement more primitive, hardware-oriented functions like routing, addressing, and flow control.
Data communication in the OSI model starts with the top layer of the stack at the sending side, travels down the stack to the sender's lowest (bottom) layer, then traverses the physical network connection to the bottom layer on the receiving side, and up its OSI model stack.

The OSI model was introduced in 1984. Designed to be an abstract model and teaching tool, the OSI model remains a useful for learning about today's popular network technologies like Ethernet and protocols like IP.


The Open Systems Interconnect (OSI) model has seven layers. This article describes and explains them, beginning with the 'lowest' in the hierarchy (the physical) and proceeding to the 'highest' (the application). The layers are stacked this way:

• Application
• Presentation
• Session
• Transport
• Network
• Data Link
• Physical

PHYSICAL LAYER

The physical layer, the lowest layer of the OSI model, is concerned with the transmission and reception of the unstructured raw bit stream over a physical medium. It describes the electrical/optical, mechanical, and functional interfaces to the physical medium, and carries the signals for all of the higher layers. It provides:

• Data encoding: modifies the simple digital signal pattern (1s and 0s) used by the PC to better accommodate the characteristics of the physical medium, and to aid in bit and frame synchronization. It determines:
  
  
  • What signal state represents a binary 1
  • How the receiving station knows when a "bit-time" starts
  • How the receiving station delimits a frame
• Physical medium attachment, accommodating various possibilities in the medium:
  
  
  • Will an external transceiver (MAU) be used to connect to the medium?
  • How many pins do the connectors have and what is each pin used for?
• Transmission technique: determines whether the encoded bits will be transmitted by baseband (digital) or broadband (analog) signaling.
• Physical medium transmission: transmits bits as electrical or optical signals appropriate for the physical medium, and determines:
  
  
  • What physical medium options can be used
  • How many volts/db should be used to represent a given signal state, using a given physical medium

DATA LINK LAYER

The data link layer provides error-free transfer of data frames from one node to another over the physical layer, allowing layers above it to assume virtually error-free transmission over the link. To do this, the data link layer provides:

• Link establishment and termination: establishes and terminates the logical link between two nodes.
• Frame traffic control: tells the transmitting node to "back-off" when no frame buffers are available.
• Frame sequencing: transmits/receives frames sequentially.
• Frame acknowledgment: provides/expects frame acknowledgments. Detects and recovers from errors that occur in the physical layer by retransmitting non-acknowledged frames and handling duplicate frame receipt.
• Frame delimiting: creates and recognizes frame boundaries.
• Frame error checking: checks received frames for integrity.
• Media access management: determines when the node "has the right" to use the physical medium.

NETWORK LAYER

The network layer controls the operation of the subnet, deciding which physical path the data should take based on network conditions, priority of service, and other factors. It provides:

• Routing: routes frames among networks.
• Subnet traffic control: routers (network layer intermediate systems) can instruct a sending station to "throttle back" its frame transmission when the router's buffer fills up.
• Frame fragmentation: if it determines that a downstream router's maximum transmission unit (MTU) size is less than the frame size, a router can fragment a frame for transmission and re-assembly at the destination station.
• Logical-physical address mapping: translates logical addresses, or names, into physical addresses.
• Subnet usage accounting: has accounting functions to keep track of frames forwarded by subnet intermediate systems, to produce billing information.

Communications Subnet

The network layer software must build headers so that the network layer software residing in the subnet intermediate systems can recognize them and use them to route data to the destination address.

This layer relieves the upper layers of the need to know anything about the data transmission and intermediate switching technologies used to connect systems. It establishes, maintains and terminates connections across the intervening communications facility (one or several intermediate systems in the communication subnet).

In the network layer and the layers below, peer protocols exist between a node and its immediate neighbor, but the neighbor may be a node through which data is routed, not the destination station. The source and destination stations may be separated by many intermediate systems.

TRANSPORT LAYER

The transport layer ensures that messages are delivered error-free, in sequence, and with no losses or duplications. It relieves the higher layer protocols from any concern with the transfer of data between them and their peers.

The size and complexity of a transport protocol depends on the type of service it can get from the network layer. For a reliable network layer with virtual circuit capability, a minimal transport layer is required. If the network layer is unreliable and/or only supports datagrams, the transport protocol should include extensive error detection and recovery.

The transport layer provides:

• Message segmentation: accepts a message from the (session) layer above it, splits the message into smaller units (if not already small enough), and passes the smaller units down to the network layer. The transport layer at the destination station reassembles the message.
• Message acknowledgment: provides reliable end-to-end message delivery with acknowledgments.
• Message traffic control: tells the transmitting station to "back-off" when no message buffers are available.
• Session multiplexing: multiplexes several message streams, or sessions onto one logical link and keeps track of which messages belong to which sessions (see session layer).

Typically, the transport layer can accept relatively large messages, but there are strict message size limits imposed by the network (or lower) layer. Consequently, the transport layer must break up the messages into smaller units, or frames, prepending a header to each frame.

The transport layer header information must then include control information, such as message start and message end flags, to enable the transport layer on the other end to recognize message boundaries. In addition, if the lower layers do not maintain sequence, the transport header must contain sequence information to enable the transport layer on the receiving end to get the pieces back together in the right order before handing the received message up to the layer above.

End-to-end layers

Unlike the lower "subnet" layers whose protocol is between immediately adjacent nodes, the transport layer and the layers above are true "source to destination" or end-to-end layers, and are not concerned with the details of the underlying communications facility. Transport layer software (and software above it) on the source station carries on a conversation with similar software on the destination station by using message headers and control messages.

SESSION LAYER

The session layer allows session establishment between processes running on different stations. It provides:

• Session establishment, maintenance and termination: allows two application processes on different machines to establish, use and terminate a connection, called a session.
• Session support: performs the functions that allow these processes to communicate over the network, performing security, name recognition, logging, and so on.

PRESENTATION LAYER

The presentation layer formats the data to be presented to the application layer. It can be viewed as the translator for the network. This layer may translate data from a format used by the application layer into a common format at the sending station, then translate the common format to a format known to the application layer at the receiving station.

The presentation layer provides:

• Character code translation: for example, ASCII to EBCDIC.
• Data conversion: bit order, CR-CR/LF, integer-floating point, and so on.
• Data compression: reduces the number of bits that need to be transmitted on the network.
• Data encryption: encrypt data for security purposes. For example, password encryption.

APPLICATION LAYER

The application layer serves as the window for users and application processes to access network services. This layer contains a variety of commonly needed functions:

• Resource sharing and device redirection
• Remote file access
• Remote printer access
• Inter-process communication
• Network management
• Directory services
• Electronic messaging (such as mail)
• Network virtual terminals

How to take Backup of Android Phone Contacts and SMS

In our daily usage of mobile we may loose our Contacts or important SMS which is not really a good thing to be happen. So, we need to get back those lost details If you are using an Android Phone here we are delivering you the best methods to Backup your Android Phone Contacts and SMS in this post.

The methods which we share here are Offline and Online methods, they have their own importance and I recommend these two. So read along these methods and if u face any problem in accessing these methods feel free to comment below.

Backup Your Android Contacts And SMS – Offline Method

The Offline method is very simple and easy method, Many Android users don’t know about this method which is quite easier. In this we are making a copy of our Contacts or SMS on memory card which can also be deleted so I recommend you to save this back up on your Computer or Laptop.

How to Make a Backup of Android Contacts:

• Open your Contacts.
• In the Contacts Click on the Menu.
• You will find a option like “Export To SD” there.
• If you are asked for permission To create a Vcard, Click YES.
• Then a copy of contacts will be created on memory card.
• I recommend you to save a copy of this on PC.

Backup Your Android Contacts And SMS – Online Method

The Online method of backup Android Contacts and SMS can be done in two ways one is through by an available App in Play store or by Gmail.

1. How to Backup Android  SMS Using the App:

Backup through an App is a quick and straight process, They are many Apps available in the Play store of Android but i recommend this SMS Backup & Restore. This is the best app and it is available for free of cost. This App helps you to store your Contacts and SMS in a directory. Follow the below steps

• Download the App from Play store or from the below link.
• After Installing the app
• Open the App Click Backup button and it will be backup
• Click on the restore for restoring and follow the process.

Download Here: Android

2. How to Backup Android Contacts Online

Android OS was created by Google, it is a known fact and Google had made forced or compulsory to Android users to use an Google account with that device. This Google Account can be used to access all other Google Products Like Gmail, YouTube, G drive and many more and from this Gmail can use to Backup your contacts Online. Follow the below steps.

• Open Settings option from your Menu.
•  You can find “Account And SYNC” or “Google Account” click on it.
• And Click on “SYNC Contacts” once you found it.
• After clicking on it your Contacts will be saved on Gmail Online.
• You can access your Contacts from Gmail when ever you needed.
• If you changed your device you can use this account and Sync your contacts to that respective device.

IPHONE FireChat Messaging App: Look Ma, No Internet!

FireChat, an iPhone app designed for anonymous hyperlocal communication, could change the way we connect with one other: It does not require an Internet connection or even a cell signal to work.

FireChat takes advantage of the Multipeer Connectivity Framework in iOS 7. This feature allows developers to connect devices to each other using Bluetooth, WiFi, and peer-to-peer connections.
Users must be within a maximum of 100 feet of another to use the Nearby feature (though they can connect with other users around their countries through the Internet in the "Everyone" chat room); it works best when users are within 30 feet of each other. However, if there are many people using the app within a close range of each other, the network becomes larger and more robust.

'Limited by Distance'

"You may be connected to a person by Bluetooth or WiFi that is less than 30 feet away from you, but chatting with others that are outside that radius because of the network created by all the connections combined," Jim McGregor, principal at Tirias Research, told TechNewsWorld. "The advantage is that you don't worry about cellular or Internet connectivity, but you are limited by distance and the number of people that are logged into the application at the time."
This type of connectivity is also called a "mesh network," where all the devices in a network relay data to the others.
"We thought that FireChat would provide a great example of what's possible with P2P mesh networks," Christophe Daligault, head of sales and marketing at FireChat developer Open Garden, told TechNewsWorld. "This demonstrates that you don't need the Internet for everything."
FireChat users can chat and share photos with either one person or a group. Users choose a screen name and need not use their Facebook account or email address to login. There are no passwords to remember, which adds to the idea that people use the app anonymously. Open Garden also promises that the app has no significant impact on battery consumption.
Users have flocked to the app, with around 1.4 sign-ups per second, according to Daligault.

'Sweet Spot'

"FireChat seems to keep on exploding in countries when it hits the sweet spot in terms of density," he said. "It has reached the top 10 amongst social networking apps in more than 80 countries, ahead of Facebook and WhatsApp. Right now it is No. 1 in Spain, for example."
Open Garden had privacy in mind when creating FireChat.
"Many apps provide great person-to-person communications," Daligault noted. "At the same time, there are growing concerns for privacy and perhaps general Facebook fatigue. So this seems like the best way to bring a new way to communicate to the iPhone."

Music Festivals, Sporting Events

The app would seem to have a deeper impact at events where many people are gathered. At music festivals, for instance, people have trouble finding a cell network connection due to traffic density.
The Burning Man festival, meanwhile, takes in the middle of the desert, where connectivity is often at a premium. Conferences, sporting events, and conventions are also events where the app might prove useful, while travelers who get separated in a crowded market might use it to find each other again.
It is not quite clear what features Open Garden will add to FireChat. For now, the company is focused on removing bugs and doing a better job of explaining how the app works, according to Daligault. However, Open Garden is planning to launch an iPad app, and those interested in an Android version can sign up to be notified.