Introduction

Before deciding which technology is superior, let's talk a little more about these two tecnologies:

• CDMA: stands for Code Division Multiple Access. Both data and voice are separated from signals using codes and then transmited using a wide frequency range. Because of this, there are more space left for data transfer (this was one of the reasons why CDMA is the prefered technology for the 3G generation, which is broadband access and the use of big multimedia messages). 14% of the worldwide market goes to CDMA. For the 3G generation CDMA uses 1x EV-DO and EV-DV. It has a lot of users in Asia, specially in South Korea.
• GSM: stands for Global System Mobile. Even though it is sold as "the latest technology" in several countries, this technology is older than CDMA (and also TDMA). But keep in mind that this doesn't mean that GSM is inferior or worse than CDMA. Roaming readiness and fraud prevention are two major advantages from this technology. GSM is the most used cell phone technology in the world, with 73% of the worldwide market. It has a very strong presence in Europe.

TDMA technology is the less used from the three main digital technologies (GSM, CDMA and TDMA) and we think it will gradually be replaced to CDMA or GSM. That's why the GSM vs CDMA war. At one corner, GSM operators say it is better "because it uses a SIM chip, it is the most used technology worldwide, it is more secure and it is more advanced". On the other corner, CDMA followers say it is better "because it is the 3G generation chosen technology and GSM will migrate to CDMA since CDMA is more advanced..."

But which one of these statements are correct? Acordingly to Nokia, "this discussion is not about technology anymore, but about market". We think this is the best way to describe the war between these two cell phone technologies.

In the beginning, GSM was in fact superior. It had more services and allowed more data transfer. But CDMA, facing the advantages of the competitor standard, soon delivered the same features found on GSM. Nowadays, it is not possible to say that GSM services are better than CDMA. Multimedia messages, video, high-speed Internet access, digital camera and even PDA function are some of the features we can found on both technologies. The new CDMA 1XRTT technology, which previews what G3 cell phones will bring, is more advanced than EDGE, technology from the beginning of 3G generation, allowing higher transfer rates.

Even the GSM SIM card advantage, that allows you to change your cell phone and keep your phone list, is being surplaced by some CDMA operators with a service that allows you to store your phone book on the operator's database, allowing you to recover your phone book even if your cell phone is stolen (which is not possible with GSM, since if your cell phone is stolen, your SIM card will be stolen together). Notice that recently a new accessory called SIM backup was released, which allows you to backup the data stored in your SIM card. Also some GSM operators are offering a similar backup service.

So, nowadays both technologies are equiparated in technology, but this picture won't be like that in the future. Afterall, CDMA evolution ground is wider and in a few years it will be superior than GSM. This means that GSM operators will disapear? Not at all. They will migrate over CDMA and the war will continue, because the existing CDMA operators chose to use 1xEV-DO and1XEV-DV technologies for their 3G network and the existing GSM operators have opted for a different technology, called WCDMA. Also, even though the current GSM operators will migrate to WCDMA, they still can use their existing GSM network. So users won't feel anything special when the operators shift to the new cell generation (3G), independently from the technology they choose.

Alphabet Soup: What are GSM, CDMA, and TDMA?

How do you pick wireless phones for your business? The secret is in the letters.

The technology may seem dense, but what helps is to understand that there are three main categories of cell phones represented by an alphabet soup of foreboding anagrams: GSM, TDMA and CDMA. GSM is a type of TDMA. And, if that isn't confusing enough, GSM and CDMA are the main competing cell phone technologies.

In order to make the right decision on cell phone technology for your business and employees, it's important to understand the basics. Here's a rundown on what the letters stand for and how the technology works:

GSM IS MOST WIDELY USED

GSM stands for Global System for Mobile Communications. If you are making a phone call, it almost certainly is on GSM, the de-facto cell phone technology standard today. More than two billion customers worldwide use GSM phones, an estimated 80 percent of mobile phone users globally, according to the GSM Association, the London-based trade group that represents 690 GSM mobile phone operators in 214 countries and territories. GSM uses several different frequency ranges to connect calls. Like radio stations, each region has a different band of frequency that GSM networks utilize. The Americas use 850 or 1900 MHz, and other continents use 900 or 1800 MHz. A few countries -- in Scandinavia, for example -- use 400 and 450 MHz.

GSM is known as 2G (second-generation) technology, meaning it is part of the second major upgrade in modern cell phone technology. "GSM differs from first-generation wireless systems in that it uses digital technology and time division multiple access [TDMA] transmission methods," says the GSM Association.

• Advantages: The technology is mature. The network is stable. The features are robust. This leads to more consistent service and less signal deterioration inside structures, such as buildings.
• Disadvantages: GSM transmission has a pulse nature which can interfere with some electronics, including pace makers and hearing aides, according to the GSM Association. This is why hospitals require people to turn off their cell phones.

GSM IS A TYPE OF TDMA

TDMA stands for Time Division Multiple Access. A common radio technology, TDMA is the foundation of GSM. As the name suggests, time division multiple access takes designated broadcast frequencies and divides them up so multiple users can use them.

• Advantages: This technique frees up other broadcast signals for other uses.
• Disadvantages: A well-noted challenge is the interference caused by multiple users sharing the same bandwidth. The new 3G Wireless technology, which uses CDMA, provides less call interference.

CDMA IS THE FOUNDATION FOR 3G WIRELESS

CDMA stands for Code-Division Multiple Access. Originally invented during World War II in England to thwart German wire interference, CDMA splits each phone conversation into pieces that follow unique but random routes. The Costa Mesa, Calif.-based CDMA Development Group describes it as a "'spread spectrum' technology, allowing many users to occupy the same time and frequency allocations in a given band/space."

Other technologies use one particular wireless frequency to transmit information. CDMA uses multiple paths (hence the name code-division multiple access) on each transmission, making it difficult to stop or eavesdrop on a particular conversation.

Qualcomm brought CDMA technology to cell phones in the late '80s and currently owns the patents to code-division multiple access. Thus, when you use CDMA, Qualcomm is making a profit. More recently, CDMA became the foundation for the newest cell phone technology, 3G Wireless.

• Advantages: CDMA can accommodate more users in a frequency range than other cell phone technologies. It uses less power while covering larger areas. Less likelihood of dropped calls.
• Disadvantages: Most CDMA technology must be licensed from Qualcomm, limiting the number of competitors offering service. Service may, at times, be inconsistent. As the number of subscribers rises, the range drops.