Tuesday, May 8, 2018

Transmitting your message over a lossy channel

Late at night, I was tweeting random stuff and then the below tweet came.
Since I worked on wireless sensor networks in a previous life, I had things to say here.

Here are the ways to deal with a lossy channel, and what those mean for your writing.

A straightforward and easy way to deal with a lossy channel is to add redundancy. Repeat the message a number of times, and one transmission will make it. In writing, this corresponds to: "Tell them what you are going to tell them, tell them, then tell them what you told them."

Another way to deal with a lossy channel is that you increase the signal-to-noise ratio. This can be done via increasing transmission power and/or somehow reducing the noise. This translates to writing more clearly. Use definite, specific, concrete language. And be succinct and to the point. As you review your draft, ruthlessly cut out frivolous parts and divergence. Read the text as if you are an outsider, empathize with the reader, and try to reduce any misunderstandings this reader could have.
Kill your darlings, kill your darlings, even when it breaks your egocentric little scribbler’s heart, kill your darlings.
-- Stephen King
Another way  to deal with a lossy channel is to send a preamble. In computer networks, a syncword, sync character, sync sequence or preamble is used to synchronize a data transmission by indicating the start of data transmission.  Sending preambles also achieve frame synchronization permitting the data bits within the frame to be extracted for decoding or retransmission. In writing, this corresponds to giving advance warning and building up to where you are leading the reader.

Ok, this is pushing it a bit too much, but here it is. You can also use TDMA to deal with a lossy channel. The transmitter establishes a rythym/cadence, and the receivers are able to receive at those predetermined times the clear transmission. In writing, this corresponds to using a parallel structure, so that the reader can follow your points easier.

That's all folks.

MAD questions

1. Did you know that the receiver can also amplify its power to reduce transmission loss?

I wrote about this earlier.
Most people have an incorrect model of how radios and wireless radio communication work. The layman thinks radios are simple. The transmitter does all the heavy lifting, and puts the signal on the air. Before the signal fades away completely, if the receiver device is in communication range, it will pick up the signal by listening. This naive understanding suggests that the receiver is a passive device, as listening is perceived mostly as a passive activity. But, nothing can be further from the truth. The receiver spends considerable energy to power its radio and amplify the signal in order to receive it.

So, this thing is very symmetrical. If a text is hard to understand, you can power up your reading game to decipher it better. Similar techniques help here also for dealing with the lossy transmission channel as well.

But this has a limitation. "When the receiver powers its radio to amplify signals, it is also amplifying noise. The signal to noise ratio (SNR) determines successful reception: if the signal has not faded, it will get amplified more, stand out, and decoded correctly. This gives raise to an interesting question: When there is no signal in the channel, what does the receiver radio hear?" To learn the answer you should read that post.

2. Is that all you got? 5 lousy writing analogies from radio transmission?
No analogies to MIMO, RFDI, or software defined radio? My analogy game must be getting weak.

3. What are your analogies to writing?
Another analogy I often use for writing is that of showcasing a garden. You are a gardener, you cultivated a great garden, and you are exhibiting it to visitors. How do you showcase your garden and lead them to the ? Initially, you will need to guide the visitors which paths to take, without guidance they will take arbitrary paths and get lost. So, take care to prune frivolous paths lest they get distracted, gently guide them toward the centerpieces and highlights of your garden. Give them a tour. Don't be too pushy either.

Related links

How I write
How to write your research paper
How I read

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