CDMA Cell Phones Now Getting Rid of Irritating Interference

With some 4.6 billion cell phone subscribers the world over, the cellular networks erected by cell service providers like Verizon or ATT&T are burdened by a substantial amount of traffic. With so many people constantly transmitting data - voice traffic, text messages, pictures, etc - over a shared network, the process can be likened to a room full of people shouting at the top of their lungs.

So how can any one user manage to communicate with another specific user in the middle of all that constant noise? The answer is CDMA cell phones. Code Division Multiple Access or CDMA cell phones operate by allowing multiple users to communicate over a single physical channel by assigning two connected users a unique code. Alternative channel access methods including Time Divided Multiple Access - TDMA - and Frequency Divided Multiple Access or FDMA.

An analogous scenario describing the differences between each method would be a room at a crowded party, where the room in question is the shared cellular network. With so many people talking all at once, it would be difficult to concentrate on talking to any one person. In order to isolate communication, each conversation between two people could occur one at a time - this would be TDMA. Or, each conversation could be held at a different pitch or volume, which would be similar to FDMA.

CDMA would be equivalent to each conversation in the room being spoken in a different language. Because every other language would be indistinguishable, those conversations would simply be ignored as background noise, allowing one to concentrate on whichever conversation was in their language. This is what CDMA cell phones do - when two callers are connected, they are each assigned a shared code so that data transmitted between them is channeled to that code and only that code.

Since every other user has been assigned their own unique code, data can be isolated between intended callers while still traveling along shared physical channels. Otherwise, every someone using the same network made a call, the data would be transmitted to every user connected to that network.

Another advantage to this method is that many unique codes can operate over the same channel simultaneously - as opposed to TDMA where network capacity imposes a limit on the number of active calls, meaning a much greater amount of call traffic can be handled by a single cell site. In fact, compared to TDMA, even smaller amounts of network capacity or bandwidth can handle an even greater amount of traffic, handling the massive transmission of data much more efficiently. And with 4.6 billion cell phone subscribers, a number that is swelling each year, the ability to handle all of that traffic is essential to maintaining the infrastructure of mobile communication.