Blu-ray: The King of Optical Storage Technology

Let's turn towards the era of multimedia. IT has played a very leading role in digital multimedia, movies, music etc. The chief requirement in this field is 'storage'. This storage must be rich, reliable, secure, easily available and easy to handle. The first handy storage for computers was 'floppy disc' invented by IBM in 1971. The floppy had a little data storage capacity of 1.44 MB which was not fit to store multimedia files.
Later in 1982, Sony Inc. of Japan invented a new medium to store a huge information. This was 'Compact Disc' simply called as CD. CD was originally invented for storage and playback of digitally recorded sound. CD was later allowed to store other digital files. CD is still used as standard physical medium for storage of digital sound. The capacity of CD is 700 MB. It can store 80 minutes of uncompressed digital audio with high bitrate of 1441 kbps. CD is still very popular and widely used medium for data. Sony also developed a special format of CD to store video also. This format was VCD (Video Compact Disc) which is still used. VCDs contain 80 minutes of moderate-quality video with CIF resolution and MPEG-1 as video codec. VCDs also got popular all over the world.

In the same time, the capacity of computers was highly increasing and it was found that CD cannot store this much data. Also, it was not possible to watch full-length high-quality movies on CD due to its insufficient capacity. So, there was a need of new invention. So, technicians developed a new media similar to CD in dimensions but 7 times high storage capacity. This media was DVD (Digital Video/Versatile Disc). DVD was primarily developed for storing high-quality full-length movies or videos with 4CIF resolution and MPEG-2 as video codec. DVD is now used for delivering high-quality movies. DVD has a capacity of 4.7 GB with a single layer and it almost completely fulfills all the technical requirements.

Let's turn towards our main subject. Why there was the need of new invention though DVD fulfills all requirements sufficiently? This is because of the invention of HDTV (High Definition Television) sets. These HDTV sets began to appear in 1999. HDTVs are the television sets that can support video signal of very highest resolution with improved picture, sound clearity and frame-rate. HD video files require very high memory space for storage and playback. Even though this much resolution is not available on some screens, this resolution is included as a part of signal. So, it was found that DVDs are really unable to store this HD video which requires a much more as compared to space on DVDs.

This new invention was done in 2004 by Toshiba. They invented a new media similar to CD and DVD. This invention was HD DVD. It had a capacity of 15 GB per layer. So, it could store HD movies. But at the same time, the similar invention was being done by Blu-ray disc association. This association developed a similar optical disc to CD and DVD having a rich data storage capacity of 25 GB per layer which is also much higher than HD DVD. This was 'Blu-ray Disc' officially called as BD.
So, the battle between HD DVD and Blu-ray Disc began to get permanently located in market. This battle is called as 'Optical Disc Format War' which got ended in 2008. So, BD was the winner of this war. The commercial Blu-ray Disc Player was released in 2010.


Let,s discuss about specifications of Blu-ray Disc. We will simply call it as BD throughout the rest of this article. As discussed earlier, BD can store 25 GB of data per layer. It can store this much data because it uses a laser of very shorter wavelength or color as compared to CD or DVD. In CD/DVD, the red laser of wavelength 650 nanometer is used to read/write. On the other hand, BD uses a laser of 405 nanometer. Though the name suggests 'Blue' color, the actual color of laser comes in 'Violet' region of spectrum. Due to this mechanism, BD stores 5 times more data than that allowed by DVD.











The writing speed of BD varies from 1x (4.5 MB/s) upto 12x (54 MB/s). It has the same dimensions as that of CD/DVD. BD has been released in two formats namely, recordable and rewritable. Recordable or blank BDs are called as BD-RE's. Rewritable BD's are especially developed for HD camcorders.
BDs are primarily developed to store High Definition full-length movies. They can store 1080p HD video with new and efficient codec MPEG-4 AVC or H.264. This is very popular and commonly used video codec now a days. It is also used on streaming videos of YouTube. Its official media container is .MP4.
All the Hollywood movies are nowadays delivered in both DVDs and BDs and many PC or notebook vendors are including Blu-ray Disc Drive in-built in their products.

Right now, the only drawback of BDs is that they are very costly and not affordable to common man. I think their market prices will get down very shortly. But, still we have to wait for its arrival and let's enjoy with our traditional DVDs!

Thanks and regards,
Nitish R. Muley

A conversation between a Soldier and Software Engineer in Shatabdhi Train

Hi! This post is the very much interesting to you even if you're not from IT field. Must read!
The content has been taken from Notes of a Facebook page Service Selection Board of Indian Military.


Vivek Pradhan was not a happy man. Even the plush comfort of the air-conditioned compartment of the Shatabdhi express could not cool his frayed nerves. He was the Project Manager and still not entitled to air travel. It was not the prestige he sought; he had tried to reason with the admin person, it was the savings in time. As PM, he had so many things to do!!
He opened his case and took out the laptop, determined to put the time to some good use.
"Are you from the software industry sir," the man beside him was staring appreciatively at the laptop. Vivek glanced briefly and mumbled in affirmation, handling the laptop now with exaggerated care and importance as if it were an expensive car.
"You people have brought so much advancement to the country, Sir. Today everything is getting computerized. "
"Thanks," smiled Vivek, turning around to give the man a look. He always found it difficult to resist appreciation. The man was young and stockily built like a sportsman. He looked simple and strangely out of place in that little lap of luxury like a small town boy in a prep school. He probably was a railway sportsman making the most of his free traveling pass.
"You people always amaze me," the man continued, "You sit in an office and write something on a computer and it does so many big things outside."
Vivek smiled deprecatingly. Naive ness demanded reasoning not anger. "It is not as simple as that my friend. It is not just a question of writing a few lines. There is a lot of process that goes behind it."
For a moment, he was tempted to explain the entire Software Development Lifecycle but restrained himself to a single statement. "It is complex, very complex."
"It has to be. No wonder you people are so highly paid," came the reply.
This was not turning out as Vivek had thought. A hint of belligerence crept into his so far affable, persuasive tone. "
Everyone just sees the money. No one sees the amount of hard work we have to put in. Indians have such a narrow concept of hard work. Just because we sit in an air-conditioned office, does not mean our brows do not sweat. You exercise the muscle; we exercise the mind and believe me that is no less taxing."
He could see, he had the man where he wanted, and it was time to drive home the point.
"Let me give you an example. Take this train. The entire railway reservation system is computerized. You can book a train ticket between any two stations from any of the hundreds of computerized booking centers across the country.
Thousands of transactions accessing a single database, at a time concurrently; data integrity, locking, data security. Do you understand the complexity in designing and coding such a system?"
The man was awestruck; quite like a child at a planetarium. This was something big and beyond his imagination.
"You design and code such things."
"I used to," Vivek paused for effect, "but now I am the Project Manager."
"Oh!" sighed the man, as if the storm had passed over,
"So your life is easy now."
This was like the last straw for Vivek. He retorted, "Oh come on, does life ever get easy as you go up the ladder. Responsibility only brings more work.
Design and coding! That is the easier part. Now I do not do it, but I am responsible for it and believe me, that is far more stressful. My job is to get the work done in time and with the highest quality.
To tell you about the pressures, there is the customer at one end, always changing his requirements, the user at the other, wanting something else, and your boss, always expecting you to have finished it yesterday."
Vivek paused in his diatribe, his belligerence fading with self-realization. What he had said, was not merely the outburst of a wronged man, it was the truth. And one need not get angry while defending the truth.
"My friend," he concluded triumphantly, "you don't know what it is to be in the Line of Fire".
The man sat back in his chair, his eyes closed as if in realization. When he spoke after sometime, it was with a calm certainty that surprised Vivek.
"I know sir.... I know what it is to be in the Line of Fire......."
He was staring blankly, as if no passenger, no train existed, just a vast expanse of time.
"There were 30 of us when we were ordered to capture Point 4875 in the cover of the night.
The enemy was firing from the top.
There was no knowing where the next bullet was going to come from and for whom.
In the morning when we finally hoisted the tricolour at the top only 4 of us were alive."
"You are a...?"
"I am Subedar Sushant from the 13 J&K Rifles on duty at Peak 4875 in Kargil. They tell me I have completed my term and can opt for a soft assignment.
But, tell me sir, can one give up duty just because it makes life easier.
On the dawn of that capture, one of my colleagues lay injured in the snow, open to enemy fire while we were hiding behind a bunker.
It was my job to go and fetch that soldier to safety. But my captain sahib refused me permission and went ahead himself.
He said that the first pledge he had taken as a Gentleman Cadet was to put the safety and welfare of the nation foremost followed by the safety and welfare of the men he commanded... ....his own personal safety came last, always and every time."
"He was killed as he shielded and brought that injured soldier into the bunker. Every morning thereafter, as we stood guard, I could see him taking all those bullets, which were actually meant for me. I know sir....I know, what it is to be in the Line of Fire."
Vivek looked at him in disbelief not sure of how to respond. Abruptly, he switched off the laptop.
It seemed trivial, even insulting to edit a Word document in the presence of a man for whom valor and duty was a daily part of life; valour and sense of duty which he had so far attributed only to epical heroes.
The train slowed down as it pulled into the station, and Subedar Sushant picked up his bags to alight.
"It was nice meeting you sir."
Vivek fumbled with the handshake.
This hand... had climbed mountains, pressed the trigger, and hoisted the tricolour. Suddenly, as if by impulse, he stood up at attention and his right hand went up in an impromptu salute.
It was the least he felt he could do for the country.
PS:- The incident he narrated during the capture of Peak 4875 is a true-life incident during the Kargil war. Capt. Batra sacrificed his life while trying to save one of the men he commanded, as victory was within sight. For this and various other acts of bravery, he was awarded the Param Vir Chakra, the nation's highest military award.

A Small Attempt to Make You Look Into the Future: 4G

The vision of mankind is always beyond the future. The communication technology has developed very rapidly since last few decades. The mobile phone has became the window to the world of information. While 3G is revolutionary thing that man has achieved. The attempts are being made to develop 4G that is the fourth generation communication technology. Very soon within a year the 4G will be ready for deployment. I explained you briefly about 1G, 2G & 3G. This post is targeted towards all the technical predications about 4G.

Although 3G was revolution and just like extension to existing 2G services, 4G is a evolution. 4G is entirely new thing distinct from 2G and 3G telephony. 4G is chiefly aimed to enable users to have uninturruptible and and amazingly high-speed internet access which is give rise to several new features, for example real-time HD video conferencing, streaming, live TV, online gaming, telepresence etc. The whole mobile network architecture is redesigned to achieve high-speed connectivity.

The air interface used in 4G, as explained before is LTE (Long Term Evolution). Just like 2G uses TDMA, 3G uses WCDMA, 4G uses a new technology known as OFDMA (Orthogonal Frequency Division Multiple Access). The core network of 3G is WCDMA. Similarly the core network in 4G is referred as SAE (System Architectural Evolution). This core network is flat all IP network. The major advantage of SAE is that it is designed in such a way to accommodate all networks such as GSM, CDMA, Wi-fi (IEEE 802.11) , Wimax (IEEE 802.16) . That is the device supported with Wi-fi, Wimax etc. can be also supported by SAE. 4G uses MIMO (multiple-input and multiple-output) technique to achieve this much data rate. MIMO is the use of multiple antennas at both transmitter and receiver to improve communication performance and efficiency.

The 4G is totally devoted to data communication and there is no support for traditional voice calls. You cannot dial a phone number directly. Thus, all voice calls are VoIP calls. Your voice after dialing any number gets routed towards the IP network and not PSTN network. By the way, there is also support for IP video calls with much higher quality and less image and voice distortion as compared to 3G video call.

Considering speeds, there is peak download speed upto 1 Gbps and upload speed upto 0.5 Gbps in 4G SAE if the operator has reserved spectrum of 20 MHz.

That's all! Verizon in USA and Vodafone in Germany have successfully launched 4G services. Probably in India the, 4G will arrive after 2015 considering the interest of operators and people. I think my small attempt to make you look into the future will be indeedly successful!

Thanks and regards,
Nitish R. Muley