SHORT SUMMARY:

Analog and TDMA Digital Cell Phones are obsolete and should no longer be purchased.

CDMA provides the best service and should be considered by people who do not often travel outside of the USA. CDMA has a more reliable network and fewer dropped calls.

GSM is the standard through out Europe and most of the world. People who often travel internationally will find that GSM phones with both US and international frequency capability are a very convenient choice because a traveler can use his phone almost anywhere.

DETAILED SUMMARY:

Analog Cell Phones are obsolete and should be replaced.

Analog is the original cell-phone technology and has many disadvantages:

1. The battery life (especially talk time) is about a fourth of that of a digital phone. For most people, this is the most significant disadvantage of these phones.

2. They are more susceptible to noise, disturbances, and dropped calls; and the voice quality is not quite as clear as digital.

3. Many new features such as date, time, text messaging, web access, etc. are not available on analog Cell Phones.

4. They need much more power and thus can potentially disturb other electronic equipment, for example PaceMakers.

If reliable service is important choose CDMA

CDMA drops fewer calls and generally has better reception and stronger signals. CDMA has the best noise immunity, is the least susceptible to multipath (fading), and can talk to more than one cell at a time so that cell-to-cell handovers (a critical cause of dropped calls) are a soft exchange and not a hard switch.

Service Providers: ALLTEL, Amp'd Mobile, Cricket Wireless, ESPN, Quest, Sprint, Verizon, Virgin Mobile.

If you travel a lot internationally, consider GSM.

GSM is the international cell-phone standard and is used by almost all of the countries in the world except the U.S. and a few countries in the far east.

If a U.S. service provider has roaming agreements with foreign service providers and if the phone is World or tri- or quad-band, it is possible to carry one GSM cell phone and use it almost anywhere. When one arrives in a foreign country, the frequency of the phone must be switched using the menus in order for it to work. (Most phones now do this automatically.) There are two choices: using the U.S. SIM card already in the phone, or buying one locally. If the SIM card is not changed, roaming applies and callers must call a U.S. number to reach it. Also the rates are roaming rates and therefore much higher. If a new SIM card is purchased, it will have a local telephone number and all calls to and from the cell phone in the country of purchase will be local calls. Cards with additional air time may be purchased at almost any newspaper kiosk. They contain a code which will add the minutes purchased to the SIM card by calling a special number. If SIM cards are to be switched, the phone must be unlocked, and most manufacturers have a 30 to 90-day waiting period before a phone can be unlocked, but on the web one can find stores who will unlock the phone for a fee.

Service Providers: AT&T, Cingular, Nextel, T-Mobile.

If having a local network (friends, family, employees, etc.) is important, consider iDEN.

Service Providers: Nextel, Boost Mobile (Pay as you go).

TDMA is the original digital technology and is now being phased out.

Service Providers: AT&T, Cingular.

Reference: Wall Street Journal, Wednesday, March 10, 2004, page D1.

It is possible for a business to have only Cell Phones for its employees.

By using a Virtual PBX, a business can organize all of its communications around Cell Phones.

This has the advantage that the company need not purchase a hardware PBX and employees can be anywhere, at their desk, in the lab, on the road, at home, traveling on business, etc.

Talk Times and Phone Size for CDMA vs. GSM

Theoretically CDMA should have much longer talk times than GSM because CDMA can operate with much weaker signals than GSM, but this is not the case. GSM phones generally have longer talk times. CDMA needs less power because the code used in CDMA can select the signal out of the noise. So why then does GSM have longer talk times? My guess is that the CDMA phones also have an Analog backup whereas the GSM phones do not. Even when it is not being used, the Analog circuitry has some battery drain. Furthermore, the CDMA phones are slightly larger due to the Analog circuitry and the extendable antenna. The FCC requires that the Analog networks be maintained until February 16, 2008. It is unlikely that CDMA phones will keep the Analog backup mode after this date, and a CDMA phone with no Analog circuitry may have increased talk times and battery life. In at least one case, however, this is not true. The Motorola Razor has no analog circuitry but the GSM version has longer talk times.