Move Over, Moore: It's Shannon's Law

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A few weeks ago, an engineering elder called to pose this bit of industrial wisdom: “For the last 20 years, we’ve seen the monetization of Moore’s Law. From here on out, we’ll see the monetization of Shannon’s Law.” Haven’t heard of Shannon? Welcome to this week’s translation.

First off, one important distinction: There are laws, and then there are “laws.” Think laws of gravity, motion, thermodynamics and physics here. Not legal laws, or laws of unintended consequences, or marketing lingo that sounds peppier with “law” in the title.

In that sense, Moore’s Law isn’t technically a law; Shannon’s Law is a law of physics. It’s a physical law, meaning it’s true, universal, simple, absolute and stable.

Moore’s Law is more of an economic observation, named for Gordon Moore, co-founder of Intel Corp., who wrote a paper in 1965 stating that the number of transistors (processing power) within chips was doubling about every 18 months. It’s still true.

By contrast, and more relevant every “connected” day, is Shannon’s Law. It’s named for Claude Shannon, who did his work in the 1940s, 20 years before Moore’s.

Shannon’s Law defines “the theoretical maximum rate at which error-free digits can be transmitted over a bandwidth-limited channel in the presence of noise.” (It comes with an equation, but we’ll spare you the math.)

In other words, Shannon figured out a way to calculate how much stuff can be crammed over a broadband network, without problems, even when there is noise, which there always is.

The dramatic rise in broadband usage - upwards of 50% compound annual growth - is true on fixed and mobile networks. In London last week, some social media outlets got bogged down because of all the gadgetry trying to send pictures and videos. We are gunking up networks.

Which is why it’s important to be able to calculate throughput maximums on data networks. And to be able to ease the situation - by adding spectrum or mitigating noise.

In cable tech circles, invoking Shannon usually means you’re having a conversation about upstream (home to headend) signaling. It’s why there’s so much talk about advanced modulation and finding ways to make that slender spectral area carry more stuff.

Will Shannon’s Law get monetized like Moore’s Law did, with a fury of investment and development that lasts a half century? Let’s hope so, for the sake of clear connections and unclogged networks.



Stumped by gibberish? Visit Leslie Ellis at www.translation-please.com or www.multichannel.com/blog.

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