Sunday 7 August 2011

Arun Netravali: Father of HDTV

Matunga to Murray Hills

ARUN NETRAVALI, (President-Bell Labs, CTO- Lucent)

Shivanand Kanavi

Business India, January 22, February 4, 2001
Arun Netravali was a very busy man when we tried to meet him in Murray Hills, the headquarters of famed Bell Labs. He kept changing the appointment. Finally, we had to do a telephonic interview. He was definitely keen to meet us, but probably other corporate priorities came in the way. The temporary woes of Lucent; falling revenues, bad debts to networks, falling stock price, which has taken a massive 80 percent erosion in the last nine months; all of which finally led to the CEO being sacked in late October, might have kept Netravali busy at Lucent.

We missed an opportunity to have a spin around the famed Bell Labs, where one is said to run into a Nobel Laureate in every corridor. Handling all this talent and channelising some of their energy into commercially useful directions is obviously a challenge for its President, Arun Netravali. Bell Labs has been the mother of several inventions in fibre optics, telecommunications, computer languages, lasers and, of course, semiconductors, including the transistor. But largely, others have reaped the benefits of inventions in Bell Labs, as in the case of Palo Alto Research Centre (PARC), owned by Xerox on the West Coast.

Amidst the current boom in networking startups, mergers and acquisitions, Lucent has had a dubious distinction. It has been a nursery for many ideas, which come to fruition outside of it and when it acquires companies it is unable to retain a large percentage of key personnel from the acquired companies. Thus, Netravali and his colleagues have their work cut out.

When we asked him about optical networking and its prospects he said: "There is no question, optical is the technology of choice for long-distance communications. Today, the same fibre is carrying a larger number of bytes. Similarly, in the metro segment optical is quite established. At an enterprise level or backbone level, there is an increasing use of fibre. What has multiple possibilities is the access network. Fast optoelectronic switches and routers have to be used, since there is no optical logic or memories still. Till then, pure optical networks cannot become a reality. So, hybrid technologies are being used. What we have now are lambda routers which do not route individual packets but entire wavelengths."

Netravali does not deny the fact that there is a slow-down in the economy, which is affecting all corporations. "But it is far less than what is made out. As far as telecom spending goes, several CLECS which came as competitors to local phone carriers have suffered revenue losses or have gone down, but ILECS involved in long distance are ordering new equipment," he says. He agrees with Desh Deshpande of Sycamore that in the crunch time there is an acceleration in switching to new technologies, since you want a bigger bang with the same buck.

He warms up when you talk about video compression in which he has several patents and research papers. Netravali led the work in establishing MPEG standards and the HDTV initiative. "High Definition TV could not take off due to several reasons, one of them being the high cost of the tube and not enough investments in research worldwide. But I think it will make a comeback with convergence. Instead of TVs, you will have computer screens giving you HD pictures, once enough bandwidth becomes available," he says.

Born in a small town, Ankola in Karnataka, Netravali grew up in Matunga, Mumbai. After five years in a municipal school, he joined King George High School and later Elphinstone College. After a brilliant career in IIT Bombay, where he graduated with a BTech in Electrical Engineering in 1967, Netravali went to Rice University, Houston for his PhD. After his graduate school, he joined NASA for two years before he landed up in the Mecca of research, Bell Labs, in 1972. Since then he has steadily risen to now become its president.

To Arun family still comes first. He loves tennis and travel, but "my priority is spending time with my family," he emphasises. Arun Netravali holds over 60 patents in the areas of computer networks, human interfaces to machines, picture processing and digital television. He has been an adjunct professor at the Massachusetts Institute of Technology. He has also served on the editorial board of the IEEE, and is currently an editor of several journals.

Netravali's is an impressive story of a journey from the impoverished municipal schools of Mumbai to the highest levels of engineering research.

From Sand to Silicon: The amazing story of digital technology—By Shivanand Kanavi, Tata-McGrawHill (2004), Rupa &Co (2006)
(See: )

Pages 106-108 from Rupa & Co 2006 Edn

Netravali, currently chief scientist at Lucent Technologies, contributed enormously to digital video in the 1970s and 1980s. His work in video is widely recognised and used in media like DVD, video streaming and digital satellite TV. “In the 1970s and 1980s we had all the algorithms we needed, but the electronics we had was not fast enough to implement them,” says Netravali. Then the microchip brought a sea change. It is good to see some of the technologies we worked on get commercialised.” The Indian government honoured Netravali in 2001 with a Padma Bhushan, and the US government also in 2001, with the National Technology Award—the highest honour for a technologist in America.

Is compression a modern concept? No. That is how people have packed their baggage for centuries. Even your grandmother would say, “Keep the essentials and don’t leave any free space.”


This is not a politically correct sequel to Mel Gibson’s movie, What Women Want, but an example of how perceptual studies have advanced communications. Netravali and Jayant’s work is highly technical, but even laymen can understand some of the ideas used by them. They discovered that human perception, aural and visual, is remarkably inured to certain details. For example, Jayant and his team found that almost ninety per cent of the frequencies in high quality audio can be thrown away without affecting the audio quality, as perceived by listeners, because they get masked by the other ten per cent, and the human ear is none the wiser. This was great news for music companies, as they could now store hi-fi sound in a few megabytes of memory instead of a hundred megabytes.

Netravali also found that just applying coding algorithms would not provide enough compression to transmit full motion video. So he studied the physiology of the human eye and the cognitive powers of the viewer. What he found was this: if we are transmitting, say, the image of a person sitting on a lawn, then clearly we want good pictures of the person’s face and body but not necessarily the details of the grass. Our eye and brain are not interested in the grass.

Similarly, when we transmit a head-and-shoulders shot of a person in motion, the motion makes only a small difference from frame to frame. What we need to do is calculate the speed with which different parts of the body are moving and estimate their position in the next frame, then subtract it from the actual signal to be sent in the next frame and instead send only the difference along with the coding algorithm. If we can do that, then we can achieve a lot of compression. Jayant and Netravali did this. They also studied the reaction of the eye to different colours and used the knowledge in coding colour information. The key factor in their approach was the analysis of perception.

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