The three types of mobile phone service.
Feb 26 '01
The Bottom Line All cellular service providers are not created equal.
There are so many different providers and so many different handsets (the phones themselves) to choose from, it's easy to get confused. In fact, if you don't think you're confused about cellular service then you're either an industry insider, or you're fooling yourself.
Cellular service providers fall into one of three categories: TDMA, CDMA or GSM. Then each one has a catalogue of handsets available with which to use their service. For example, if you like the extremely popular Nokia 5100 series handset, you can get one that uses TDMA service -- the 5120 (single band) or the 5160 (dual band), CDMA service -- the 5180 or GSM service -- the 5150 or 5190. Are all these phones the same? They look and operate the same. The difference you'll notice is in the quality of service.
TDMA
TDMA stands for Time Division Multiple Access. It is the oldest digital cellular technology. It allows 3 callers to access what used to be a single frequency for analog users. The advantage of TDMA is that it is the most widespread type of service in North America. The disadvantages include lack of wideband features such as outbound text messaging and web browsing. If you intend to use your phone only as a phone, TDMA is probably still your best choice, as the other types simply don't have enough towers to provide good coverage. AT&T uses TDMA technology.
CDMA
CDMA stands for Code Division Multiple Access. The advantage of CDMA over TDMA is that its signal is more uniform and quality stays pretty much level. It is aso gaining wideband capabilities, although you will need to purchase a special handset to use these advanced features. Web browsing is text only, and only a select few sites are available. Still, if you absolutely need those stock updates on demand, and still need somewhat decent cellular coverage, this is probably going to suit your needs. Verizon uses CDMA technology.
GSM
GSM stands for Global System for Mobiles. It is the newest technology in land-based cellular phones. It is very advanced in terms of bandwidth (you will never find yourself unable to make a call because there are too many users on the system), as well as having text messaging and web browsing capabilities. GSM networks are also designed to be backwards compatible, so as new technologies emerge, GSM will be able to keep up. GSM is widely used in Europe and Asia. Unfortunately, there is very little coverage in North America, and even large cities have spotty coverage. Before buying one of these phones, research the area and find out whether other GSM users are getting a decent signal in the area you intend to use this phone. If you travel around the country, don't buy GSM. A note of caution: GSM transmitters are so tiny in comparison to their TDMA and CDMA counterparts, that many stores selling GSM phones will actually have a transmitter in their store! This way the salesman can show you how strong the signal strength is in this area. The problem is that when you leave the mall, you've left the service area too.
The job is half done
Now you should have a better idea which type of cellular service (and therefore which service provider) is right for you. All that's left is to select a handset. Fortunately, Epinions is a wealth of knowledge on the subject. Find out which models your local cellular store stocks, copy down the model numbers and research them thoroughly before making your final decision.
A final word of caution on another subject -- read the contract thoroughly before signing it. If the salesperson seems impatient and wants you to sign right away, ask him or her to help other customers while you read. If he or she persists, leave the store.
 |
|
|
|
|
|
|
Epinions.com ID:
livewire_
|
|
Member: Live Wire
Location: Vancouver
Reviews written: 80
Trusted by: 17 members
|
|
|
© 1999-2009 Shopping.com, Inc.