A wireless Analogy to Speaking/Hearing

In recent months, I have been delving deeper into Wireless Networks. And only now,have I started to have a good intuitive understanding to the whole business. I do not claim that all the thoughts expressed here are original, but I think they are interesting enough to find a mention in the blog. It also shows that most things in Computer Science are Common Sense...unlike transistors (whose working amazes me every time I read about how it works :) )

The way Wireless Networks (at least the kind we come in contact with, after all satellite communications is wireless too, but then how many of us set that up in our home? ) work is like the action of speaking/hearing for people. Just like air is a broadcast medium for sound, so it is for radio frequency as well.

If one person in a group speaks, any other (polite) person should shut up to allow the first person's voice to be heard. Of course, if the second person is far enough from the first person, they can speak concurrently without affecting each other. One of the most interesting problems in wireless is to figure out how far is far enough for nodes to be able to talk concurrently.

Clearly, how far is far enough depends a lot on how loud the speakers are. Ditto in wireless: it depends on the transmit power of nodes. Also, imagine a person speaking near heavy machinery: He'll have to be much louder than a person who is speaking in a quiet room, to be heard. So noise and interference also affect how far far enough is..In wireless, unfortunately, because many instruments apart from wireless talk at the same frequency ranges (because they are the ones that are freely available), and interference is a major problem. Microwave Ovens slow down the Internet in many a homes :).

Thats about the similarities, but there are some aspects of wireless which make it harder than hearing/speaking.. Imagine being in a noisy room and listening to a person. After every sentence being uttered, the speaker has some clue about whether the listener has heard what he said; these are because of the out-of-band signals that you get in form of change of expression of the listener, nodding etc. Imagine how annoying it would be for the listener and the speaker if the listener was forced to acknowledge that he heard the speaker right after every sentence..but thats precisely state-of-the-art in wireless these days. One good intuition looks to be that if we can exploit other out-of-band ways of acknowledging what we hear, we'll communicate better. This is difficult given the rigid capabilities of what our nodes can or cannot do, but I would have to think that when designing specific networks where you know the effect of what you communicate should be,significant gains can be made by looking out for such out of band actions..

Also, it would help a lot, if we all know what volume to talk at rather than shouting at the top of our voices or in a constant monotone (which is precisely what wireless does now, though they are moving towards changing that..). We're still primordial as far as this evolution is concerned -- its an exciting time for an interesting field!