Cellular Telecommunication – GSM, CDMA

From my last post, I have written about telecommunication in general. Here I will write more about cellular telecommunication and its technologies particularly GSM and CDMA. Both are 2G technology.

Most people now associate telecommunication with modern technologies that provide mobile communications to users both in the form of voice and data transmissions. There are a number of different standards that telecommunication companies use to provide cellular services.

Cellular telecommunication was conducted over analog system that transmits waveforms which can degrade over long distances. Because of that, cellular telecommunication has transformed to digital converting the signals into groups of numbers that could not be broken down over time and distance. As a result of this digital transformation, cellular telecommunications are based on many different standards. Phones and systems that operate on the same standard can usually work with each other.

The most popular of the digital standards are Global System for Mobile Communication (GSM) and Code Division Multiple Access (CDMA). GSM is the standard used in much of the world. In Malaysia, GSM is most common, while CDMA and PHS (PHS) mobile phone is also very popular.

In terms of data transfer speed, both technologies continue to rapidly leapfrog one another. Both provide “3G” standards or 3rd generation technologies. CDMA2000 is CMDA’s answer to need for speed. GSM’s answer is EDGE (Enhanced Data Rates for GSM Evolution) with added technologies that include UMTS (Universal Mobile Telephone Standard) and HSDPA (High Speed Downlink Packet Access) This technology is also known as W-CDMA, but incompatible with CDMA networks.

GSM phones uses SIM cards that allow phones to be instantly activated, interchanged, swapped out and upgraded, all without carrier intervention. The SIM itself in tied to network, rather than the actual phone. CDMA carriers on the other hand require proprietary handsets that are linked to one carrier only. When upgrading a CDMA phone, the carrier must deactivate the old phone then activate the new one and the old phone becomes useless.