Nov 14, 2004 05:31 PM
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(Updated Nov 14, 2004 05:31 PM)
GSM, CDMA, TDMA
What do all these acronyms CDMA, TDMA and GSM mean?
Which is Better?
Digital cellular systems arose as a direct result of the growing popularity of mobile voice services. Analog and digital phones operate on opposite ends of the radio wave spectrum, making neither type of phone compatible with the other's calling network.(Except Dual mode phones, work with both analog and digital networks). Although the analog cellular system worked well, by the late 1980s, demand was exceeding capacity in many regions. To minimize the possibility of congestion on the cellular network, digital cellular services were developed.
There are a number of different standards and technologies for wireless phones. This combination of standards and technologies can become very confusing for anyone. For a phone to work in an area other than the ''home'' area, it must be in a system that supports the technology used by that phone and in the frequency which the phone is designed to work.
Wireless system Carriers have selected one or two of these technologies which best serve their target customers. All of these technologies can serve individual subscribers well with pros and cons for each of them.
CDMA
CDMA stands for Code Division Multiple Access and incorporates spread spectrum, works by digitizing multiple conversations, attaching a code known only to the sender and receiver, and then dicing the signals into bits and re-assembling them.
TDMA
TDMA stands for Time Division Multiple Access and is a digital technology that allows multiple users to share the same voice channel by having each conversation transmitted alternately over short lengths of time.
GSM
GSM stands for Global System for Mobile communication. GSM is a TDMA digital system that converts voice and access information to digital data, and communicates those data in bursts during brief time slots allocated to multiple subscribers sharing a radio channel. This system is being used by some of the PCS operators here in the country.
PCS
PCS stands for Personal Communications Services is the name adopted by the new, wireless service providers who have been awarded licenses to operate new phone systems in the 1900 MHz frequency range. The term ''PCS'' is often used in place of ''digital cellular,'' but true PCS means that other services like paging, caller ID and Email are bundled into the service. Those same technologies are called ?digital cellular? if they are transmitting at 800 MHz. There are two ''types'' of PCS services namely narrowband and broadband.
For all of the historical and technological reasons outlined above, it appears that GSM, or some combination of GSM and CDMA, will become the long sought after grail for a global wireless standard. A universalization of wireless technologies can only stand to benefit the compatibility and development costs and demands on all wireless commerce participants.
If you are presently in the market for a new phone, my advise to you is to ignore the hype surrounding the technologies and look at service provider instead. Judge each with an eye to price, phone choice, coverage, and reputation. Technology should play a very small roll in your choice. If you follow this advice, you'll probably be much happier with the phone and service you inevitably wind up with.
