Data Transmission Record

The Internet is widely spreading around the world today. Due to the development of technologies like wi-fi or 3G issue of providing the Internet becomes less topical. Developers are now thinking how to make the Internet faster by increasing the speed of data transmission. One common approach is usage of the optical fiber.

Fotonic Group's Record

In July of 2014 Fotonic research group at the Technical University of Denmark (DTU) has come with remarkable result of providing 43 terabits of data per second (Tbps) over a single optical fiber. This world data transfer record was broken after the three years of previous 26 Tbps result set by German team at the Karlsrune Institute of technology. The result achieved by the DTU group is really important for the Internet development and makes the optical fiber technology even more vital. Let's now try to inderstand why. 

Optical Fiber

It would be impossible to break the record without existance of the optical fiber. Optical fibers are strands of very pure glass no thicker than a human hair that are used to transmit data over a long distance. They generally consist of three main parts:

• Core – central part made of thin glass 
• Cladding - layer that surrounds the core and is made of special optical material. 
• Buffer coating – outer layer made of plastic coating that protects the fiber from damage 

How does it work?

Imagine that you are standing in the long corridor which has a bend. You need to pass a flash of light through this corridor. One of the solutions is to place a mirror on the corner, so that light is reflected to the right direction. In case when corridor has not one, but many bends more mirrors can be placed on the walls of the corridor. Passing the light under the certain angle we make it reflect from one wall to another and travel successfully through all the bends.

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The same principle is used to transfer the data in the optical fiber. Light (our data) travels through the core which acts like corridor. The cladding plays role of the mirrors that keep the light inside the core. Material of the cladding is a special glass with high refractive index. This index describes the ability of the material to refract the light. High index is needed for total reflection of the light without any absorption. In such case light will bounce back to the core without any losses each time it meets the cladding. So, we can successfully transmit the huge amount of data without using much resource. (Such phenomenon is called total internal reflection in science). For better understanding, speed of 43 Tbps of data means that we can transmit 300 hours of a good quality video in one second.

What is special about the Fotonic team record?

To be honest, there have been experiments in which hundreds or even thousands of terabits of data was transmitted per second using the optical fibers. However, all these experiments were based on the concurrent usage of multiple fibers. Such technique can be used in the laboratories for the research, but is not applicable in real life. It is too complex from technical side and commercially unprofitable as more resources are used.

Fotonic group used a new type of optical fiber produced by the Japanese telecom company NTT. This fiber has seven cores, not one as in the usual type described here. Seven cores greatly increase the amount of data that can be transmitted, but as they are very thick they do not require any more space. As the companies like NTT began manufacturing such multi-core fibers for commercial use, DTU record becomes practical in real life. That’s what makes this record so special.

The dramatic growth of data traffic on the Internet (40-50 per cent annually) requires a technology that somehow can accommodate it. From another side, Internet demands a great amount of energy. It was estimated that emissions connected with the Internet consumption of energy is nearly the same as carbon emissions caused by transport industry. That is why it is so important to find a way to deal with an increasing amount of information and reducing the energy consumption at the same time. It seems like the record of the DTU’s researches can be a good solution for this problem.

References:

1) Chris Woodford. "Fiber Optics." http://www.explainthatstuff.com/. N.p., 18 June 2014. Web. 21 Oct. 2014.
2)Craig Freudenrich, Ph.D. "How Fiber Optics Work."http://computer.howstuffworks.com/ N.p., 17 Feb. 2012. Web. 21 Oct. 2014.
3) Lotte Krull. "World Data Transfer Record Back in Danish Hands."http://www.dtu.dk. N.p., 30 July 2014. Web. 21 Oct. 2014.
4) Sebastian Anthony. "43Tbps over a Single Fiber: World’s Fastest NetworkWould Let You Download a Movie in 0.2 Seconds."http://www.extremetech.com. N.p., 31 July 2014. Web. 21 Oct. 2014.

Operating system for 'Internet of Things'

Recently, BBC published an article written by Leo Kelion titled “ARM creates operating system for ‘internet things’”. Article is devoted to a new project of the well-known British computer chip designer ARM.

At the moment technology companies are creating and using different code for each of their products. ARM aims to create free operating system (mbed OS) that will make the development of internet-connected devices easier. OS will combine already existing Internet Protocols, various technologies like Bluetooth, 2G, 3G, Wi-Fi, etc. and create one solution that can be used on a big range of devices. Designers expect the first devices with their operating system to be launched in the second half of 2015.

This news is very important as it can change our usual lifestyle. To clarify it, we should understand the concepts of operating system and ‘Internet of Things’.

Internet of Things

Today not only computers can access Internet. Everyday objects like some cars or even light bulbs are now connected to World Web. IoT concept refers to technology that allows connecting these objects to the Internet and to each other with controlling and monitoring their later status.  

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Smart houses are good example of how things can be web controlled.  Temperature, lightning and security system control by the means of the Internet are popular functions used in smart houses at present. IoT technology’s target is to expand these available functions. Imagine that all household items at your house are connected with each other and, for example, with your smart phone via Internet. You then will be able to manage and secure your house from any place with sufficient Internet connection. As the map provided by World Bank illustrates, currently little places are remained without Internet access, so it is practically possible to implement the idea into the real life.

Data from WorldBank

However, there is another problem rises. According to the forecast from ABI Research posted on their official site, “the installed base of active wireless connected devices will exceed 16 billion in 2014, about 20% more than in 2013.” They forecast 40.9 billion devices to be a part of IoT by 2020 and yet there is no straight way to connect things that are so different from each other. How to design system that can deal with fridge and garden sprinklers at the same time? ARM offers their operating system as a solution.

Operating System.

Operating system is the most important program installed on the computer. Think about it as a big project's chief manager. He gives tasks to other workers, monitors that everything is going in a right way and in a right time, works as a channel between client and people working on the project. Operating system works in the same way. It gives base for other programs to be installed, manages these programs and provides the interface for user to give commands to computer and see the outcome.

ARM is creating such “manager” for the devices of IoT. The main principles that company used are represented in the figure below.

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The first principle is connectivity. As it was written in the article this operating system “is no longer a differentiating technology. It’s enabling one”. Many unlike devices could be connected together by the means of the OS. System will be efficient as very little memory is needed to use it (few hundred kilobytes) and productive as producers will not spend much time on creating new codes for each product anymore. Developers also include security tools that  are necessary in the global network with many participants and a lot of information in it.

ARM are those who actually started the project, but other companies like IBM and Ericsson are now their partners in the IoT area.  According to article more than 3 million developers will be involved in the IoT activities by 2019. With an assumption that all the stated ideas will be implemented into the real life, we can expect that soon our lifestyle will greatly change and technology actually will surround us everywhere.

References and useful links

• Kelion, Leo. "ARM Creates New Operating System." BBC News. N.p., 1 Oct. 2014. Web. 03 Oct. 2014.
• Internet of Things - Cisco article, Forbes article
• ARM official site

Recursion

Welcome to blog about Computer Science!

My name is Kamilya Altynbekova and I am a first year student at Nazarbayev University. Since the childhood I was interested in computers and at high school began attending programming classes. Simple interest has grown up to passion and this passion brought me to Computer Science (CS) department of my university.

As a student I often face a problem of finding resources that provide short and simple explanation of needed material. Some concepts are either explained in a very complex way or too simply for true understanding. Here I will try to explain some concepts that are very useful not only for CS majors, but for all science students. 

General definition

This blog is going to be about recursion. I have chosen this concept from my "Fundamentals of Programming" syllabus, but it is widely used in other sciences besides CS.

First of all, let’s take a look at the image on the right. Notice, that each inner image is just a repetition of the initial image.  This picture is a simple example of the recursion. According to Cambridge University Press Dictionary term recursive is “involving doing or saying the same thing several times in order to produce a particular result or effect”

There are many other examples. Physicist can probably think about two mirrors placed towards each other. The recursion occurs as the mirrors infinitely reflect each other. Example from Math is the Fibonacci sequence. We constantly repeat summing up the last two numbers in the sequence to obtain the next one.  

Often recursion is difficult to understand because it has a specific meaning in a variety of areas and disciplines. However, the main idea of repetition always remains the same.

Recursion in Computer Science

Most commonly recursion is used in computer science and programming where it has very specific definition. Recursion in programming is “a technique involving the use of a procedure or function that can call itself”. 

The classical example of problem requiring such technique is a factorial function. Factorial of some number x is simply the product of all integers from 1 to this number x. Factorial of number 10 is 10!=1*2*3*4*5*6*7*8*9*10, where “!” is the notation used for factorial. Notice that it is possible to rewrite it in the form 10! = 10*9! It is true for any factorial, so generally x! = x*(x-1)!

Now it is possible to see how this problem relates to our topic.  In order to find a factorial of 5, it should be multiplied by factorial of 4 which is 4 multiplied by factorial 3 and so on. We use factorial to find factorial, so the recursion is useful here. 

Now when we can see the pattern algorithm for a program can be developed. Recursive function usually consists of two main elements: base step and recursive step. Base step sets condition for function to stop calling itself. It prevents program from running infinitely and crashing. In our example with factorial such condition is reaching the number 1. In recursive case function is allowed to call itself. While x more than 1 the formula obtained above is simply used. (click here for more details)

Despite the existence of the alternative solutions recursion makes the solution much simpler and cleaner.

We considered the general algorithm without any actual code because our goal is just to understand the general concept. I hope that we achieved this goal and you have an idea of what is recursion.

Visit my blog for new blogs and feel free to comment!

References:

Explanation of Recursion. (n.d.). Retrieved September 23, 2014, from http://www.programmerinterview.com/index.php/recursion/explanation-of-recursion/