Friday, January 20, 2012

Where is the Spectrum

In 1999, we were attending a training in job for a large Indian corporation. A group head on wireless systems was conducting the training. With infectious enthusiasm, he asked us if we know what the next big thing is. We listened with rapt attention.

"It is WAP - Wireless Application Protocol". You can find the details here. It sounded uncannily similar to the movie Graduate's famous one-word dialogue "Plastics".

We, few undergrads at Jadavpur University, studying at pre-final year had a very similar plastic moment, too. Upon hearing the guest lecture of a industry big-shot, where the word VHDL was introduced, a Professor sitting in front row looked backwards and with hush hush tone told us - "VHDL - it is very important". Without figuring what exactly to do, a fellow student jotted VHDL quickly on a note pad - the single note that he took during the entire presentation.

Technology is all about this plastic moments. Technology insiders look around to grab the next big thing and make big out of it. In techno-jargon, it is known as riding the technology wave.

Sometimes, the next big thing also becomes the crux of a hot political debate to make it further interesting. Take energy for example. Solar energy, energy scavenging, energy harvesting are as much important technology milestones as in political races, too. You need to reduce power to retain power, as reflected in the high-priority agenda of Barack Obama.

In Indian political scenario, we got used to the term 2G spectrum. While there are potentially millions of outlets to inform you about Raja, Karunanidhi and Chidambaram, a few notes can be found about what a spectrum is. I thought of summarizing my ideas here.



The innovation began with the discovery of radio - that you can send information through air. The information is encoded with 0s and 1s and then, those are converted into a wave. The antenna, which is cleverly hidden in mobile phones, can send and receive the waves. Now, the waves have a property called frequency, which in plain words mean how many times the waves rise and fall within a period. When the information is carried, the sender and the receiver needs to agree on a particular frequency of wave. It is similar to two conversations in a room. One in a soft tone and another in a loud, harsh tone. Both can go on in parallel. To better use the total available wave, we need to separate the frequency zones between different communicating groups. For example, emergency fire service will use a particular frequency and two talkative friends will use another frequency. The total available wave is called frequency spectrum. For building practical radio (i.e. mobile receiver and transmitter), we have to limit the frequency within a certain zone. Therefore, frequency spectrum for mobile communication cannot be expanded like elastic. And that's the crux of the problem why, allocating spectrum is crucial. Following is a spectrum distribution chart for USA.


Now what is with 1G, 2G and so on ? Realizing that there are so many issues with building a good radio, people thought of working together would help. Like, if a person calling from a wave frequency wants to talk to a receiver receiving in different wave frequency - how to convert that ? Or if the radio receiver can detect the information even if the waves got distorted on the way ? So, all the large telecommunications operators in the world came under the same umbrella called International Telecommunication Union (ITU) and started charting the path with new release of standards. Alongwith the standards, came the agreements on which frequency spectrum the standard will be used. To make room for new standards, old standards are systematically phased out.

Naturally, when a new standard is drafted, much is promised - like improved connectivity, improved video and audio quality. Telecommunication service providers make sure that these are realized by developing equipments according to the specifications in the standards. In parallel, what happens is the allocation of frequency spectrum license.

There is where everything went wrong and well, you can find the rest of the story in daily news.

2 comments:

  1. Anupam, I found your article ends abruptly without touching upon what is spectrum usage, why is there bandwidth crunch, and what is spectrum controversy all about!!! Anyway, over and above the technical issues involved, the genesis of the controversy lies in technology politics. Yes, in a country, as big and populous as India, this high-end technology has been hijacked by politics. Technology is a boon to humanity when it is useful to the greater section of the society. However, when technology serves more to fill in the pockets and pander to the vested interests of some greedy politicians who understand not even the 'a-b-c' of technology, it becomes more of bane than a boon to this world. And it takes the form of techno-economical cliche, like "spectrum controversy" - a big contemporary buzzword having more of a negative than a positive connotation, that's only adding more fuel to the fire of corruption that raging the nation at large!!!

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  2. @PsD, I tried to keep it as simple as possible - here is the line "Therefore, frequency spectrum for mobile communication cannot be expanded like elastic. And that's the crux of the problem why, allocating spectrum is crucial."

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