GSM technology features

When you hear the buzzword “GSM,” what comes to mind? If you’re not sure, don’t worry. Cell phone technology may not be at the top of your list, particularly if you live in the U.S. However, GSM (Global System for Mobile communications) is important and the rest of the world would agree. GSM technology is the standard for more than 200 countries.

Why is it important to you? Consider some features that GSM offers you.

• When using cell phones for business outside of the U.S., you can often use your GSM-enabled cell phone without needing to buy or rent another and pay expensive per minute charges.
• GSM uses a SIM (Subscriber Identity Module) as its “brain”. This smart card is removable and often transferable to another phone, with your contact numbers preserved.
• Built-in security is not infallible, but is generally considered better than some other network technologies.
• GSM cell phones, unlike some of their competition, are totally digital, providing excellent voice and text messaging quality.
• GSM pioneered SMS (Short Message Service). You are probably more familiar with its common name, "text messaging." Most of its competition has adopted this service, but “purists” often consider GSM to be better.

Considered original second generation technology, the newest cell phones using GSM with some enhancements are often considered “3G,” state-of-the-art third generation systems. The network itself is rather complex, but has a wonderful reputation for reliability and quality.

CDMA technology features

CDMA (Code Division Multiple Access) technology is sometimes preferred to GSM by hardware experts. Voice and data signals are separated and transmitted using a wide range of frequencies. The hardware gurus believe this leaves “more room” for data transmissions, making CDMA more efficient. They will further argue that CDMA is the real 3G (third generation) technology, although GSM often gets equal credit.

While GSM is used in more countries, particularly throughout Europe, than any other, CDMA technology is quite popular in Asia as well as the U.S. CDMA is often considered the wonderfully enhanced version of TDMA (Time Division Multiple Access).

Although they share similar words and accomplish the same goal, they are different and distinct methods of transmitting bits of information. Yet most cell phone network experts agree that CDMA will eventually replace TDMA totally as a preferred provider of voice and data, leaving GSM as its primary competition.

Along with the predominance of GSM in Europe, CDMA has sometimes been compared unfavorably to the wonderful SIM (Subscriber Identity Module) offered by GSM technology. The SIM card allows you to store your “phone book” and contact information in a removable and transferable format to other GSM cell phones.

CDMA is combating this disadvantage with the ability (from some servicers) to store your important contact information on a database. This gives you the advantage of not worrying about the condition of a SIM card or even accessing your phone book if your cell phone is stolen as your data resides on a large server, not a tiny memory card.

iDEN technology features

Integrated Digital Enhanced Network (iDEN) technology, originally designed by Motorola, is used with the Sprint/Nextel service in the U.S. iDEN technology is also offered in countries as diverse as Canada, Argentina, Japan, and Israel. Nextel and iDEN were made famous by their ability to combine the features of a two-way radio – push to talk to people in your radio network – and true cell phones.

Since Sprint purchased Nextel, there is uncertainty about the long-term use of iDEN with this company, as Sprint uses CDMA technology to service its cell phone users.

Another feature of iDEN technology that many users like is its use of a SIM (Subscriber Identification Module) just as GSM phones do. Should you switch from iDEN to GSM, your SIM card, containing your entire phone book and contact information, can often be used in your new GSM phone to eliminate the tedious re-entry of your saved data.

While the real possibility of Sprint/Nextel converting all service to CDMA, iDEN still projects no other service changes. iDEN technology continues to be supported and improved. The other countries and private cell phone systems in the U.S. that use iDEN remain committed to continue using this technology with success.

Match carriers with their technology

Different cell phone carriers use different technology to deliver your calls and data. They all try to convince you they are the best, which is understandable.

All current technology achieves the same goal, routing your voice and data transmissions from origin to receiver. They accomplish this objective with different transmission methods and protocols, but all seem to work successfully.

Here is the menu of major carriers in the U.S. and the technology they use:

There are many smaller wireless carriers, using both GSM and CDMA, in the U.S. The majority of cell phone carriers in Europe use GSM technology. Wireless providers in all countries publish the networks they use and data on the number of subscribers they service. This information is available from a variety sources over the Internet.

The differences in technology are typically “transparent” to the average user. If you frequently travel outside the U.S., you might consider a wireless carrier that uses GSM technology, as it is considered to be the global standard, particularly in Europe. Yet, other popular technologies, like CDMA and iDEN, are also used in many countries and territories.

Using your cell phone overseas

Overseas use of your cell phone presents challenges that don’t normally exist when you’re traveling throughout the U.S. Just as you face difficulties using a Verizon-enabled cell phone on a T-Mobile network, you will encounter similar, but more troubling challenges using your U.S. phone in many other countries. Here is what you should know to avoid most problems.

Throughout most of Europe (actually in over 200 countries), the standard technology is GSM (Global System for Mobile communications). In the U.S., wireless carriers that use GSM technology include AT&T (formerly Cingular) and T-Mobile.

The other major cell phone carriers, like Sprint/Nextel and Verizon use different technology. Therefore, if you use a U.S. network that employs GSM technology, you have an advantage, but you still need to do more.

You still probably need an “unlocked” GSM phone to allow overseas use. Many cell phones are “locked”, dedicated to the wireless carrier that services them. Changing carriers may not be possible, even in the U.S., with a locked phone. Unlocking separates the cell phone from any particular carrier and permits its use on a comparable network. Unless you’re a cell phone hardware guru, have a third party perform the unlocking procedure for you.

Assuming you have a GSM phone, you may be able to activate your handset for international use. However, just connecting to a foreign network typically results in overly expensive usage charges, sometimes up to $5.00 per minute.

There is a way to save a lot of money, however. GSM phones use a SIM (Subscriber Identification Module) card that stores pertinent data and phone numbers. Buy a prepaid SIM card for the country you’re visiting. Your usage fees will be reasonable, incoming calls (even from the U.S.) are often free, and you’ll have great budgetary control for your overseas use and trip.

See also: Using a cell phone overseas

Cell phones and domestic use

While Traveling Around the U.S., except in the most mountainous and sparsely populated areas of the U.S., your cell phone should work perfectly. If you’re traveling in the mountains, you should understand that cell phone signals enjoy moving in a straight line, not bouncing around off hills.

Sparsely populated areas may cause the same result – no service – for a different reason. Many wireless carriers shy away from constructing communication towers in areas that don’t have enough users to support their networks.

Be aware of long distance calling issues when traveling in the U.S. Remember, your phone number has an area code and calls made outside of that code normally incur long distance charges. Some people forget that if they are from Dallas, but find themselves in San Diego calling a local number, this call is still long distance since their cell phone number is a Dallas exchange.

If you travel frequently, you should consider cell phone deals that include free domestic long distance calls. You’ll never have to worry about a disturbing surprise on your cell phone bill after a trip.

Roaming charges is another issue that you should address. While traveling, should you need to access a roaming network, you may be subject for some unpleasantly large charges for the privilege of using these "foreign" communication towers. Once again, wireless carriers often offer plans that include free roaming service.

Learn whether this includes calls placed through their own towers, but outside of your “home” service area or if it also includes calls placed through totally different carriers, as well.

Comparison of digital and analog technology

Just as nationwide TV networks have always broadcast with analog technology, land line telephones and most cell phones historically used analog signals. From a technical perspective, the differences from digital are significant. As a user, you will enjoy the benefits and capabilities of digital networks greatly, but voice quality improvements may or may not be discernible.

Analog technology uses changes in amplitude and/or frequency to transmit voice or data signals. Relying on a continuous electronic signal, employing increases or decreases in amplitude or different frequencies, analog technology has served us well in TV, telephone, and original computer communications.

Its limitations, however, are many. Among the more important are its susceptibility to outside interference (thereby causing problems with transmissions), tendency for quality downgrades over greater distances from the sending point, lack of ability to send high volumes of information, and, sometimes, sporadic voice and data reception.

Digital technology eliminates most, if not all, of the shortcomings of analog transmissions. Digital networks send “pulses” instead of a constant stream of electricity. These pulses are in digital format, just as your computer works and thinks.

This feature eliminates most of the potential outside interference, maintains quality signals over long distances, allows data to be “compressed” so huge amounts of information can be sent quickly, and delivers a much more consistent signal quality most of the time.

Cell phone voice quality is improved and all forms of other PDA services (text messaging, Internet connections, e-mail, etc.) are now available to you from your wireless carriers. There are still cell phones and networks that use analog technology for cost and reliability reasons. Yet, in the future all will eventually be digital.

Roaming and when it may concern you

Roaming is classically defined as using your cell phone when outside of your “home” service area, as defined by your wireless carrier. If you have a wireless plan that clearly defines your “home” service area as your county or state, every time you use your cell phone outside of this jurisdiction, you will typically pay “roaming charges”. Understand that these fees can be both annoying and, at times, quite expensive.

These extra charges exist because when you’re roaming you’re using cell towers not defined as home transmitters, or you are using another carrier’s roaming network, for which they demand a fee. Therefore, while you may be disappointed in your wireless carrier, they may simply be passing through a charge they incurred by the other network.

For example, you use network A and are based in New York. You travel to Arizona and need to access network B to make or receive cell phone calls. You are not a subscriber of network B, but you are using their towers to communicate. They want to be paid for this use of their network.

There are now many wireless carriers that offer plans without roaming fees. Another option is to opt for a plan that has a wide “home” service area. For example, you live in Boston and your business or pleasure travels typically involve all of New England, but few other areas. Having a “regional” service area plan that covers the Northeast might save you all but the most unusual roaming charges; beware of that trip to New Mexico.

Peak and off-peak minutes explained

The difference between peak and off-peak cell phone usage used to be a serious concern for most wireless users. New programs offered by many cell phone carriers in recent years have lessened this issue. You should still have a good understanding of the difference, however.

Peak minutes are those applied to the highest usage time of the typical business day, generally from around 6:00 a.m. to 9:00 p.m. Eastern Time. While you certainly hope that your normal business day doesn’t often extend through this entire time period, understand that the U.S. has four major time zones.

While you may be watching your favorite TV show at 9:00 p.m. in Boston, your peers in Seattle may still be working at 6:00 p.m. Pacific time.

Off-peak minutes generally apply to the lowest wireless carrier usage, typically after 9:00 p.m. until very early morning and most weekends. “Social” callers often become clock-watchers, waiting for the strike of 9:00 p.m. to become chatty. The cost of off-peak cell phone minutes is often 50% (or more) less than peak per minute charges.

However, many plans now offer a fixed rate for both types of minutes, include 1,000 or more off-peak minutes, or even unlimited off-peak and Nights/Weekends usage. You’ll pay a bit more per month for these plans, but they often can save you hundreds of dollars if you are an active cell phone user.

About calling circles

Some wireless calling plans offer the use of personal networks or calling circles. The idea of a calling circle is that you can designate a certain amount of phone numbers as part of your personal calling circle and any calls to and from these numbers will be of no charge to you.

You choose which telephone numbers are in your calling circle and change them as often as once a month. Sometimes, you are not even limited to mobile numbers or cell phone numbers within your network. In these cases, the numbers can be to any phone – landline or cellular.

As of November 2007, one of the most commonly known calling circle program is T-Mobile’s "MyFaves." You can designated five phone numbers as "MyFaves" and calls to and from these numbers are free.

One thing to keep in mind is that cellular phone plans that include calling circles can be more expensive per month than standard plans. Be sure to research to make sure that the additional monthly cost of the plan is worth the money you’d save by calling the people in your circle without the plan.