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WORKING WITH OPERATING SYSTEM

Posted by Unknown Rabu, 08 Februari 2012 0 komentar

WORKING WITH OPERATING SYSTEM

We all know what a “computer” is, it’s one of those very useful electronic devices that perform a variety of operations in accordance with a set of instructions called program. By now all mid-aged teenagers might know that a computer, in fact all electronic devices work on a simple cycle called I-P-O cycle. Also it’s crystal clear that I/O would obviously stand for Input and Output. Now what is P? P stands for “processing”. Processing actually is what the computer does and displays the output in response of the input. Being a computer science engineer we must know that, whatever this system does is actually what generally we humans do. So then how does it make a difference? The difference is that the computer works on a set of rules and these rules are called protocols. It has some syntax i.e. conventions which it is bound to follow. Since the processor is responsible for processing, it must be faster than what our human brain is capable of doing and, it’s always faster.

Thus if computer processes just in the same way we humans solve a problem then, it should practically use the same formulas we work on, then what is going to make this system run on the same formulas? Well if we can control the flow of signal as per our wish and compel the system to do what we instruct then we can get the desired output, isn’t it? But that too doesn’t seem pleasing as it’s not as easy as it seems to appear. To compel it to do something we must have certain rules which it should follow. These rules are nothing but “software”.

Software, another very complex but important term in computing that is to be understood in depth. Software represents the set of programs that governs the operation of a computer system and make the hardware run. Technically software is a man-made program that can control the flow of information depending on what we have coded it for. It’s just like an object designed for particular work (Pencil’s work is to write where Eraser’s work is to erase).

Software can be subdivided into two basic types:

• System Software.

• Application Software.

System Software:

As we observe the word “system” appears here so it obviously has got something to do with the controlling of system. System software primarily focuses on managing the hardware run properly, flow of information in and out and governs the working of Application software.

It can be further divided into two types, viz. Operating System and Language Processors.

Ex. of Operating system: Windows, Macintosh, UNIX, Linux, etc.

Ex. of Language processors: Assembler, Interpreter, Compiler.

Application Software:

Set of programs necessary to carry out operations of specific application. These are the programs that are written as well as used by the humans. These programs are written to fulfill the personal requirements of human like an application for playing games. Does neither good nor any bad to humankind or machines, just for our entertainment we have made the software. Similarly there are several applications.

Ex. of the Applications: AutoCAD, MS-Word, etc.

OPERATING SYSTEM:

An operating system can be defined as a program which acts as an interface between a user and the hardware (i.e. all computer resources).

A simple way to understand the operating system is:

The above shown sketch depicts the interaction starting from User till the Hardware/C.P.U.

To understand the Operating system (here onwards OS), we compare it with real world. Our duty is to study and excel. For that we go to different institutions. Now we are nothing but the ‘End User’. Teachers act as application software, each expert in their field, conveying us the knowledge. Here the Principal has no work practically i.e. they don’t consult us directly but, they still control the institution and its proper functioning. Here hardware is the classrooms, benches and other tools we use in school. The Principal who they act as OS over here has to maintain proper conditioning of the hardware, functioning of application software and also control the interaction between the three.

In the same way OS acts as a guide, one that has been designed such that it maintains a correct balance between user and applications used by them, and the proper flow of data between the applications and hardware.

Now as I have mentioned that an OS looks on both the hardware and the user, the OS must have to separate units to do so. Thus OS has two parts: Kernel and the Shell.

Kernel is responsible for interacting with the hardware and the Shell is responsible for interacting with the user.

Types of OS:

Real-time

A real-time operating system is a multitasking operating system that aims at executing real-time applications. Real-time operating systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The main objective of real-time operating systems is their quick and predictable response to events. They have an event-driven or time-sharing design and often aspects of both. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.

Multi-user vs. Single-user

A multi-user operating system allows multiple users to access a computer system concurrently. Time-sharing system can be classified as multi-user systems as they enable a multiple user access to a computer through the sharing of time. Single-user operating systems, as opposed to a multi-user operating system, are usable by a single user at a time. Being able to have multiple accounts on a Windows operating system does not make it a multi-user system. Rather, only the network administrator is the real user. But for a Unix-like operating system, it is possible for two users to login at a time and this capability of the OS makes it a multi-user operating system.

Multi-tasking vs. Single-tasking

When only a single program is allowed to run at a time, the system is grouped under a single-tasking system. However, when the operating system allows the execution of multiple tasks at one time, it is classified as a multi-tasking operating system. Multi-tasking can be of two types: pre-emptive or co-operative. In pre-emptive multitasking, the operating system slices the CPU time and dedicates one slot to each of the programs. Unix-like operating systems such as Solaris and Linux support pre-emptive multitasking, as does AmigaOS. Cooperative multitasking is achieved by relying on each process to give time to the other processes in a defined manner. MS Windows prior to Windows 2000 and Mac OS prior to OS X used to support cooperative multitasking.

Distributed

A distributed operating system manages a group of independent computers and makes them appear to be a single computer. The development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system.

Embedded

Embedded operating systems are designed to be used in embedded computer systems. They are designed to operate on small machines like PDA’s with less autonomy. They are able to operate with a limited number of resources. They are very compact and extremely efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems.

Kernel

With the aid of the firmware and device drivers, the kernelprovides the most basic level of control over all of the computer's hardware devices. It manages memory access for programs in the RAM, it determines which programs get access to which hardware resources, it sets up or resets the CPU's operating states for optimal operation at all times, and it organizes the data for long-term non-volatile storage with file systems on such media as disks, tapes, flash memory, etc.

User interface

Every computer that is to be operated by an individual requires a user interface. The user interface is not actually a part of the operating system—it generally runs in a separate program usually referred to as a shell, but is essential if human interaction is to be supported. The user interface requests services from the operating system that will acquire data from input hardware devices, such as a keyboard, mouse or credit card reader, and requests operating system services to display prompts, status messages and such on output hardware devices, such as a video monitor or printer. The two most common forms of a user interface have historically been the command-line interface, where computer commands are typed out line-by-line, and the graphical user interface, where a visual environment is present.

Most of the OS today run in Graphical User Interface or commonly called GUI.

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Mobile Computing: The Story Of G's

Posted by Unknown Selasa, 31 Januari 2012 0 komentar

THE STORY OF G's

Computing is defined as the use of computers or any such device which works on some program or set of programs. Now as we had already started a discussion on Cloud Computing, these are the techniques on which this computing implicated.

Present day, we would have come across these terms like- GSM, GPRS, CDMA, TDMA, EDGE, 3G, 4G, etc. Now being the “End-User”, we hardly try to know what they are, nor bother to know how these things differ. What we bother about, is that how to use them.

Now where’s the fun in watching a movie when you can’t even remember a scene or a punch dialogue. The same applies in everything we do. Thus, my motive from writing and spreading this article is that we try to know the slightest of details about the various “G’s”.

Now going way back to the past, when inventions of devices like radio, TV, Telephone, W-Phone (Wireless Telephones) were at its work. Now it’s not a joke to convert one form of energy into other, it takes great understanding. Thus, many inventions were combined to achieve what we understand as Wireless communication. The concepts used were the idea behind working of radio and that of a telephone. With this they came to know that sound energy captured from one end can be converted to electrical signals with help of magnets and routed to a desired location in the form of waves through a transmitter. Also it can be received at the other end by a receiver and converted back to electrical coding which can be further converted to sound. All this was possible because of the common factor “frequency” between electricity, magnetism and sound. Now the factor of differentiating signals from one device to other was an issue i.e.: making a device unique. We all are familiar with the quantum theory, and various electromagnetism phenomenons. Now this helped us in relating various factors like speed of light, frequency of signal, bandwidth, wavelength of signal, amplitude of signal etc. Then, a particular electrical coding was assigned to each device which differentiated them from each other.

That was a bit of history of how things began. Now we head straight away to what is this “G”. ‘G’, in computing stands for “Generation”.

0G:

It all began with zero-generation mobile systems called the Mobile Radio Telephone System (MRTS).

The image shown above is a MRTS based device, a predecessor of the modern telephone. In MRT System the technologies used were as follows:-
PTT: Push to Talk.
MTS: Mobile Telephone System.
IMTS: Improved Mobile Telephone System.

AMTS: Advanced Mobile Telephone System.

Each of them differed in frequency range i.e.: kept increasing from one technology to other. This MRTS/ 0G, system of communication started as early in 1940’s and ended up by mid 80’s.

1G:

During early 80’s researches on the first generation (1G), communication systems had been started up. This was surely the best invention in field of communication technology. Instead of converting a single frequency into electrical signal a packet of data was converted into a particular signal and it was analog in nature. Thus, 1G speed varied between that of a 28k modem (28kbit/s) and 56k modem (56kbit/s), meaning actual download speeds of 2.8KBytes/s to 5.6KBytes/s.

2G:

With the beginning of 1G marked the evolution of present day Mobile Cellular Systems. 2G, or the Second Generation system works on a GSM standard. Now GSM stands for Global System for Mobile communication. This is based on TDMA i.e.: Time Division Multiple Access. The only difference between 1G and 2G is the signals were analog then and digital in the later.

TDMA works by dividing a radio frequency into time slots and then allocating slots to multiple calls. In this way, a single frequency can support multiple, simultaneous data channels.

GSM uses a narrowband TDMA, which allows eight simultaneous calls on the same radio frequency.

The other standard for 2G system is CDMA or Code Division Multiple Access. This uses a spread- spectrum technique where data is sent in small pieces over a number of discrete frequencies available for use. Each user’s signal is spread over the entire bandwidth by unique spreading code. At the receiver end, the same unique code is used to recover the signal.

Now both of the above techniques i.e. the entire 2G system was built mainly for voice services and slow data transmissions.

Thus there was a need of modification. But the modification though should have been considered as 3G, did not match up to the uplink/downlink speed.

2.5G:

This is nothing but GPRS or General Packet Radio Service. It is used to describe 2G-systems that have implemented a packet-switched domain in addition to the circuit-switched domain. It does not necessarily provide faster services because bundling of timeslots is used for high speed circuit-switched data services (HSCSD) as well. GPRS could provide data rates of 56 kbit/s - 115 kbit/s. It can be used for services such as Wireless Application Protocol (WAP) access, Multimedia Messaging Service (MMS), and for Internet communication services such as email and World Wide Web access

2.75G:

GPRS networks evolved to EDGE networks with the introduction of 8PSK encoding. Enhanced Data rates for GSM Evolution (EDGE), Enhanced GPRS (EGPRS), or IMT Single Carrier (IMT-SC) is a backward-compatible digital mobile phone technology that allows improved data transmission rates, as an extension on top of standard GSM. EDGE was deployed on GSM networks beginning in 2003—initially by Cingular (now AT&T) in the United States.

EDGE is standardized by 3GPP as part of the GSM family and it is an upgrade that provides a potential three-fold increase in capacity of GSM/GPRS networks. The specification achieves higher data-rates (up to 236.8 kbit/s) by switching to more sophisticated methods of coding (8PSK), within existing GSM timeslots. Presently EDGE is known as Enhanced Data rates for Global Evolution.

Mixture of GSM/ GPRS/ EDGE is considered to be the modern day 3G.

3G:

LTE or 3GPP in Long Term Evolution is what should be considered as modern day 3G. As it matches the required data rates of 2 Mbit/s for stationary or walking users, and 384 kbit/s in a moving vehicle, but does not actually clearly specify minimum or average rates or what modes of the interfaces qualify as 3G, so various rates are sold as 3G intended to meet customers expectations of broadband data i.e.: 2.5G and 2.75G are used as 3G.

3.5G:

UMTS or Universal Mobile Telecommunication System is a standard and the higher version of 3G. It is called 3.5G as it doesn’t match up the requirements of 4G but can be appreciably close. It is based on W-CDMA i.e.: Wideband CDMA (increased bandwidth).

Mobile-WiMax also happens to match up the requirements as 4G but the technique used and the data rates are much closer to 3G thus often termed under ‘3.5G’.

3.75G:

HSPA or High Speed Packet Access is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA) that extends and improves the performance of existing WCDMA protocols.

A further 3GPP standard, Evolved HSPA (also known as HSPA+), was released late in 2008 with subsequent worldwide adoption beginning in 2010.

HSPA supports increased peak data rates of up to 14 Mbit/s in the downlink and 5.76 Mbit/s in the uplink. It also reduces latency and provides up to five times more system capacity in the downlink and up to twice as much system capacity in the uplink, reducing the production cost per bit compared to original WCDMA protocols. Many HSPA rollouts can be achieved by a software upgrade to existing 3G networks, giving HSPA a head start over WiMAX, which requires a dedicated network infrastructure.

Evolved HSPA (also known as: HSPA Evolution, HSPA+, I-HSPA or Internet HSPA) is a wireless broadband standard defined in 3GPP release 7 and 8 of the WCDMA specification. Evolved HSPA provides data rates up to 84 Mbit/s in the downlink and 22 Mbit/s in the uplink (per 5 MHz carrier) with multiple input, multiple output (MIMO) technologies and higher order modulation. It utilises multiple base stations to potentially double the channels available utilising MIMO principles.

MIMO or Multiple Input and Multiple Output is the use of multiple antennas at both the transmitter and receiver to improve communication performance. It is one of several forms of smart antenna technology. Note that the terms input and output refer to the radio channel carrying the signal, not to the devices having antennas.

MIMO technology has attracted attention in wireless communications, because it offers significant increases in data throughput and link range without additional bandwidth or increased transmit power. It achieves this by spreading the same total transmit power over the antennas to achieve an array gain that improves the spectral efficiency (more bits per second per hertz of bandwidth) or to achieve a diversity gain that improves the link reliability (reduced fading). Because of these properties, MIMO is an important part of modern wireless communication standards such as IEEE 802.11n (Wifi), 4G, 3GPP Long Term Evolution, WiMAX and HSPA+.

3.9G:

LTE-Advanced is termed as 3.9G. 3.9G because it is closest to 4G but differs in the desired data rates. Also the technology adopted in LTE-Advanced is a combination of W-CDMA, MIMO & Evolved UMTS Terrestrial Radio Access (E-UTRA).

LTE Advanced (Long-term-evolution Advanced) is a candidate for IMT-Advanced standard, formally submitted by the 3GPP organization to ITU-T in the fall 2009, and expected to be released in 2012. The target of 3GPP LTE Advanced is to reach and surpass the ITU requirements. LTE Advanced is essentially an enhancement to LTE. It is not a new technology but rather an improvement on the existing LTE network. This upgrade path makes it more cost effective for vendors to offer LTE and then upgrade to LTE Advanced which is similar to the upgrade from WCDMA to HSPA. LTE and LTE Advanced will also make use of additional spectrum and multiplexing to allow it to achieve higher data speeds. Coordinated Multi-point Transmission will also allow more system capacity to help handle the enhanced data speeds. Release 10 of LTE is expected to achieve the LTE Advanced speeds. Release 8 currently supports up to 300 Mbit/s download speeds which is still short of the IMT-Advanced standards.

Data speeds of LTE Advanced
	LTE Advanced
Peak Download	~1 Gbit/s
Peak Upload	300-500 Mbit/s

4G:

Fourth Generation Tele-communication system uses the HSOPA High Speed OFDM Packet Access, i.e.: OFD Multiplexing.

OFDMA or Orthogonal Frequency Division Multiple Access is the latest research field. It is a multi-user version of the popular Orthogonal frequency-division multiplexing (OFDM) digital modulation scheme. Multiple access is achieved in OFDMA by assigning subsets of sub-carriers to individual users as shown in the illustration below. This allows simultaneous low data rate transmission from several users.

Data speed rate of 4G systems:

Peak Download- 1Gbit/s. Not less than this.

Peak Upload- 500Mbit/s. Not less than this.

Benefits of OFDM:

► Over CDMA/W-CDMA.

•OFDM can combat multipath interference with more robustness and less complexity.

•OFDMA can achieve a higher MIMO spectral efficiency due to providing flatter frequency channels than a CDMA rake receiver can.

•No cell size breathing as more users connect.

► Over TDMA.

•Allows simultaneous low-data-rate transmission from several users.

•Pulsed carrier can be avoided.

•Lower maximum transmission power for low data rate users.

•Shorter delay and constant delay.

•Contention-based multiple access (collision avoidance) is simplified.

•Further improves OFDM robustness to fading and interference.

OFDMA is still a theory, as there has not been any practice of it till now. America claims to run on 4G but in some areas only. That can be considered LTE-A.

That’s not it researches have been started already for “5G”. Something that would give a promising of 750 Mbit/s uplink and a downlink of 1 Gbit/s even when used by someone in a moving vehicle.

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Apple loses latest round in Android patent fight

Posted by Unknown Sabtu, 28 Januari 2012 0 komentar

Apple came up short in the latest twist in the seemingly endless Android patent saga, as a Dutch court ruled today that Samsung's Galaxy Tab can be sold in the Netherlands and distributed throughout the European Union.

Apple came up short in the latest twist in the seemingly endless Android patent saga, as a Dutch court ruled today that Samsung's Galaxy Tab can be sold in the Netherlands and distributed throughout the European Union.

Essentially, the Gerechthof's-Gravenhage appeals court in the Hague upheld an earlier decision made by a lower Dutch court that ruled Samsung's Galaxy Tab tablets did not infringe upon Apple's patents related to the iPad and could thus be sold in the Netherlands.

TIMLINE: Patent madness! A timeline of the Android patent wars

BACKGROUND: Dutch court slams brakes on Samsung Android phone sales in Europe

Although the ruling means the Galaxy Tab will continue to be sold in the EU, it does not affect the EU-wide preliminary injunction against the Samsung Galaxy smartphone that a lower Dutch court issued last year. Patent blogger Florian Mueller noted today that the latest ruling in favor of Samsung comes just a week before a German court is slated to rule on whether to lift that preliminary injunction and thus clear the Galaxy smartphone to be sold throughout the EU. Mueller also said that the upcoming rulings will be crucial in determining just how much protection Apple will get from competitors that design products similar to its own.

"[T]he two companies need the courts in various jurisdictions to clarify where Apple's exclusive scope of protection ends and Samsung's freedom to compete begins," Mueller writes. "There's no mathematical formula based on which they could simply agree that Samsung's products are allowed to have a degree of similarity of up to (for example) 70%. Instead, they need guidance from judges."

This week's court ruling was a big win for Samsung, which had already voluntarily agreed to stop selling its Galaxy Tab 10.1 in Australia last year until it resolved its patent disputes with Apple. In a statement issued today, the company said that the ruling "again demonstrates that Apple's products simply do not warrant the intellectual property protections it believes."

Apple, Microsoft and other big tech companies have been suing manufacturers that create and sell devices based on Google's Android operating system for alleged patent infringement since 2010. Apple got the ball rolling by filing a lawsuit against HTC for allegedly infringing on 20 Apple patents in March 2010 and Microsoft followed shortly after by announcing it had reached a licensing agreement with HTC where the company would pay Microsoft royalties in exchange for the right to sell Android-based devices.

To combat these patent suits against Android vendors, Google has attempted to boost its own patent portfolio through both its failed bid to acquire valuable tech patents formerly held by Nortel and its announcement that it intends to pay $12.5 billion to acquire Motorola Mobility and its portfolio of 24,500 patents.

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Cloud computing: Taste The Cloud

Posted by Unknown Rabu, 25 Januari 2012 0 komentar

In our daily working with computers, its not uncommon to come across software that provide such obivous benefits that it becomes hard to live without them.of late, with cloud computing, this has also become the case of web services. Below are some utilities that will make your life simpler.

Use IFTTT to build bridges between diferent services
we are well versed with the concepts of 'events' and 're-sponses'. when a phone rings, we pick it up; if the oven's timer goes off, we check on our baking. the web services 'if this, then that' (IFTTT) now brings this concepts of events and responses to the internet.
         The resource lets you pick from large number of event sources e-mail services, social networks, online storage sites, photo sites, RSS feeds, etc and supports myriad action and responses that cab be carried out automatically in case a certain condition is met. Take Facebook, for instance. it has a feature that lets people tag in photos. this means your photo collection will not only the pictures you take, but also those in which your tagged. now consider the cloud storage service called Dropbox. Using IFTTT, you can set up an "if-then" condition that will automatically store the picture in which you are tagged to your dropbox account.
So whether its automatically updating your Twitter image when you update your Facebook image, or something more useful as getting an SMS notification of stock/currency rate updates, IFTTT can handle nearly everytning.
The resource offers numerous "channels" which can serve as source of events (most popular web services are included) and also as recipients of actions to be performed.
Website:http://ifttt.com

Use Attachments.me to search within your Gmail attachments
Gmail might have brilliant search system, but unfortunately, it doesn't search within your attachments. The creators or Attachments.me understand this need, and have built a system to index the content of your attachments.
        To use the service, create an Attachment.me account by signing up with your existing Google account. It will then being indexing as many as the last 10,000 messages in your inbox. Once it is done crawling through your email, you will be able to search through them through their website or even in Gmail itself if you install add-on (available for Firefox and Chrome).
   If you're bothered about privacy, don't worry. Attachments.me downloads a copy of your attachments in order to index them, but it stores them in an encrypted form on a secure server - and your account information can only be accessed by you. Additionally, if you remove your account, Attachments.me deletes all your data from their server. The only thing they maintain are statistics on the kinds of terms people search for so as to improve their systems.
Website: http://attachments.me

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Throwable Panoramic Ball Camera

Posted by Unknown Kamis, 17 November 2011 0 komentar

The Throwable ball camera shoots amazing 360-degree photos.

John pfeil of the Berlin Technical University holds a throwable panoramic ball camera in Berlin October 28,2011.

Throwable Ball Camera :

This boll camera will show all possible camera angles during a sporting event.

Device contains,

36 fixed-focus 2 megapixel mobile phone camera modules. This modules are mounted in a robust, 3D-printed, ball shaped enclosure.
This device is handles just like a ball.
It will shows 360 degree, all possible angle photos.
An accelerometer, it is used to measure launch acceleration.
Integration lets us to predict rise time to the highest point, where we trigger the exposure.

After shooting the ball camera, pictures are downloads in seconds using USB. This camera device automatically shown in our spherical panoramic viewer.

Panoramic Camera Pics :