Saturday, April 29, 2017

What do all those networking terms mean? Network nerdery for dummies

Making sense of those acronyms and abbreviations.

"Hey, man. Did you hear that Qualcomm's new X20 modem is rated for cat 18 LTE, carries 12 spatial streams and is 4x4 MIMO capable? Isn't that cool?"

Maybe that's cool, but really how is a regular person with a regular job or who goes to regular school and has regular hobbies supposed to know? It sounds like a secret code with all the abbreviations and acronyms, and the companies who want us to buy it aren't any better at explaining: "10 times faster" "5G" "Gigabit". Those words may convey the right message — that things will be fast — but take no time to say why or how.

A lot of tech talk is this way. Engineers are lazy when it comes to typing or writing. Things like "power over Ethernet" instantly become PoE, or "impedance" becomes Z (I is for current. Of course it is.). That's why you hear words and phrases like QAM that don't mean a thing unless you stop and look them up. And usually, the answer is filled with other acronyms and abbreviations. Did I mention that engineers are lazy typists?

Because Qualcomm and some of their partners are working on changing the whole game when it comes to better wireless networking, you'll be hearing or reading this kind of stuff a lot. Here's some help so you know wtf those nerds are talking about!

  • 4G stands for fourth generation wireless. 3G was the third generation, and so on. There are standards, but companies like AT&T are allowed to just use the G as a marketing term.
  • LTE stands for Long Term Evolution. It's based on the old standards but has evolved to be faster and better at carrying data.
  • cat usually follows LTE when talking about wireless. It simply stands for category. Higher numbers are faster.
  • Carrier aggregation (sometimes LTE CA) is part of the advanced LTE standards that lets a network combine LTE signals. More radio waves equal more and faster data. You'll see it expressed as "5x20MHz" which is not an acronym and means five 20MHz signals.
  • QAM is short for Quadrature amplitude modulation. It's a method to take two different instances of the same shape signal wave and put them 90-degrees out of phase. Modulation and demodulation use both amplitude and phase to process the signal. Wireless networks and phones (and cable boxes and HDTV tuners) are designed to use Quantized QAM because square waves offer more bits per symbol with a lower SNR.
  • The entire section above this one is because I know there are some budding engineers that will read this and want that explanation. For everyone else, QAM is a way to send a signal that carries more data with less noise than there would be if you amplified a single "regular" signal. A higher number means more data and faster speeds.
  • MIMO stands for multiple inputs, multiple outputs. It's an antenna design that has both the device sending a signal and the device receiving the signal using more than one antenna at the same time, This means the signal can carry more data and have fewer errors.
  • Spatial streams are how a MIMO setup carries different signals on each antenna. The receiving device (your phone) puts them all together into one signal with lots of data. This is also called multiplexing. The more streams that can be sent at the same time, the more data is in the stream when they are put back together. 12 streams are better than 10.

This is a good start. You won't turn into a wireless engineer by reading it and there are a lot of technicalities not included here. That's by design — someone has to try and turn all this stuff into something everyone reading about it can understand.

And there a a lot more abbreviations, acronyms, and insanity when it comes to telecom terms, Toss out the ones you know in the comments so we all can have a better understanding of why our stuff is supposed to be faster in the 5G future.



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