I've previously posted about the world of acronyms in the cellular industry (see it HERE) that's so over the top I call it "acronymania."  You can hardly read a story, enter a store or order a product without hearing about GSM, TDMA, CDMA, SIMs, mini-USB, Li-Ion, NiCad, etc., etc.  It's maddening to figure out what they all stand for, much less what they mean.  In the end it's like learning to speak another language – except this one is "wireless" instead of French, Italian or Mandarin. 

Once you learn what the acronyms stand for, though, the fun really begins when you try to figure out what it means and how the technologies work.  Over the course of the next few postings here I'm going to make an attempt to explain the inner machinations of wireless technology and standards in terms that we can all – hopefully – understand.  I've taught thousands of people around the world how this stuff works and even written a book about it (you can download it free HERE or buy bound copies for your staff HERE), so maybe this can help you, too. 

By far the most mysterious issue to many people is why their phones won't work on other carrier's networks.  In other words, if you've got a Sprint phone why can't you use it on an AT&T system, or vice-versa?  If you've got a T-Mobile phone, why can't you just move it over to Verizon's system?  The answer lies in the fact that long ago the Federal Communications Commission decided to allow each of the licensees that provide cellular service (also occasionally referred to as "PCS" for "Personal Communications Service") to choose whichever of the various available technologies they wanted to deploy for their own networks. 

This is undoubtedly a fine example of the free market at work, but in this case it created a crazy quilt of various technologies around the country that are largely incompatible with each other.  They break down to two fundamentally different technologies:

• CDMA – Code Division Multiple Access
  

• TDMA (also mistakenly referred to as GSM, which is a standard, not a technology) – Time Division Multiple Access
  

Now, GSM – the Global System for Mobile Communications (or, more properly "Groupe Speciale Mobile" – see my other post HERE) is a standard and it uses TDMA to get its work done so most people refer to GSM as a technology.  It's technically incorrect, but colloquially accepted, so we'll just run with that here. 

The real issue at hand is how these two technologies – GSM and CDMA – work.  GSM, by the way, is the technology upon which AT&T, T-Mobile and most carriers in Europe and Asia utilize.  CDMA is used by Verizon, Sprint and several carriers around the world (notably a very large one in South Korea). 

I have, at various times, used the analogy of a cocktail party to describe the difference between the two technologies (as well as analog, which is the predecessor to all digital technologies including CDMA and TDMA/GSM) and will use that here as well.  In addition, with a tip of the hat to Uyless Black, author of the wonderful book "Mobile and Wireless Networks" I will also use the description of how frogs – and in particular one tiny variety called the "coqui" – communicates, which provides one of those weird real-world animal functions that either inspires a technology or easily describes it. 

In the next post we'll delve into the Wireless Cocktail Party and describe how three different parties – the analog, CDMA and TDMA/GSM parties – all differ and how the coqui (a truly diminutive creature at only about 30 MM, or about 1.5 inches) communicates by using a natural version of CDMA and TDMA combined. 

By the end, you'll know enough to explain to your friends how the technology works and will be a certifiable Wireless Wizard Apprentice.