“I have recently been researching  new cell phone service providers and have noticed that some companies use GSM technology and some use CDMA. What do these mean and is one necessarily better than the other?”

-- Suzy R.

Hey Suzy,

Cell phone carriers have two different ways to provide you with your cell phone service, Code-Division Multiple Access (CDMA) or Global System Mobile (GSM). Realistically, neither system has any significant advantage over the other but there are some personal preferences to take into consideration when choosing your service provider. Let’s start with an overview of each technology.

CDMA phones are generally considered faster than GSM phones, though not by much, and are also less likely to drop your phone calls. This technology uses a “spread spectrum” technique where data and voice signals are separated and then widely transmitted throughout the spectrum. This allows multiple users to send their data simultaneously and spreads the data through multiple cell towers, which acts as a safety net for each of your phone calls. If one tower drops your data it will instantly be picked up by another tower, protecting your calls through a process called a “hand-off”. This also allows more space for either signal, making it initially very appealing during the 3G era because of the excess space for data. However, GSM phones have made recent strides in improving their speed and are now able to compete almost evenly in terms of download and bandwidth speed.

GSM phones are developed using digital technology, which allows for a more streamlined process of sending data. All of the data leaving your phone is digitally encoded and then effortlessly streamed into the network. When data needs to be sent back to your phone, it is digitally decoded through the same system. By digitally encrypting this data, it takes up much less space and is able to be sent back and forth through the network with ease and is able to serve a much larger area of service. This technology is also able to utilize “roaming” more efficiently, allowing you to use your cell phone in any area where GSM service is available, no matter where you are in the world.

Making your decision relies heavily on your own personal preference. For example, if you frequently travel, especially overseas, you may want to consider purchasing a cell phone from a GSM carrier. GSM technology is much more prominent worldwide and these phones are able to work outside of your standard service area. CDMA phones are not able to be used overseas, as the United States is one of the few countries with prominent CDMA phone service; there is about a 50/50 market share here in the states. GSM phones also utilize Subscriber Identity Module (SIM) Cards, which are removable and can be replaced into any GSM phone to transfer personal information and reactivate/switch phones without having to go through your service provider. Some may see the SIM card system as a disadvantage; if you were to lose your phone you would also lose the majority of your data and have to purchase a new SIM card from you wireless carrier. Obviously, there are advantages and disadvantages to each system, so overview these technologies carefully to see which would best benefit your lifestyle.