FDMA, CDMA, TDMA/GSM Cell Phone Technology – A Simple Explanation Of The Differences

We all love our cell phones for sure, but what about all that FDMA CDMA TDMA GSM cell phone technology anyway? Saying “I just couldn’t live without my phone” is the trifle overdramatic perhaps statement aired by many that nonetheless gives voice to the enthusiasm and importance with which we regard our little cellular friends (if not the companies who provide the service). But what technologies are employed in cell phones anyway, and how do they differ?

First came technologies like analog cellular phones, known as Frequency Division Multiple Access (FDMA) where each cell phone call was allocated an entire channel of two frequencies (one for transmitting, the other for receiving) to itself. This proved to be wasteful as digital cell phones arrived in the early nineties; now cell phones could sample, compress and process data thanks to binary codes, all in a fraction of a second.

And with today's advanced technologies, cellular phones can do other things too, like be used for text messaging, email and cameras, later MP3 players, and JAVA gaming all because of digital technology.

One problem with analog technology is that an FDMA cell phone stakes claim to the frequencies for the full duration of the call, so this cuts down on the numbers of cell phones that can be operating at the same time in the same cellular area. And cellular analog also suffered from greater interference and less clarity than digital cell phone technology does, of whatever type; as well as being more battery thirsty and less secure from eavesdropping.

It’s All About Numbers

But, Code Division Multiple Access (CDMA), which works by assigning a code to each call and simultaneously spreading all the calls out wide in packets over a frequency range; and Time Division Multiple Access (TDMA) which sends and receives signals by splitting up the calls into time slots on shared frequencies; were soon competing to be the top "digital dog technologies" in the cellular phone world.

And they still are today, as the new cell phone champion of TDMA, which was always wider used than CDMA in North America anyway, GSM arrives from Europe. (Though albeit the American version of GSM is slightly different from that elsewhere - basically though it does the same thing the same way, it does it speaking a different cellular language and on a different frequency, known as both 1900PCS and GSM1900 in the USA - not to be confused with the carrier Sprint PCS which uses CDMA technology - just to make things simple)!

CDMA technologies were originally more secure and had greater capacity than TDMA, if less coverage. But rival technologies have now closed the gap, and TDMA adherents claim that GSM is smarter in how voice calls are encrypted. The critics of CDMA also state that a lot of the rival’s claims are theoretical as TDMA and related cellular systems like GSM are cheaper to install and operate by the hundreds of carriers in countries around the world and used much more in daily life.

Claim and counter-claim will always be with us, with the areas where one currently lags behind always stating that development will improve things. But in truth both are amazing cellular technologies which can allow us to do more with our lives and be more mobile and independent than ever before.

More than half of all Europeans own a digital cell phone (known as a mobile phone around the world) and while only around a fifth of Americans currently own a cell phone, with the coming of 3G cellular telephone technology, we’ll be relying on our cell phones even more than before for a whole raft of new and improved services.

Also see; cell phone FAQ.

Author Notes:

Matt Jacks contributes and publishes news editorial to http://www.cell-phones-n-plans.com. A cell phone industry resource that features service plan comparisons, cellular phone reviews and articles.