A mobile cellular phone, mobile phone, cell phone or simply hand phone, sometimes abbreviated to just cell, phone or hand, phone, can make and receive phone calls via a wireless phone service while the user is traveling within a specific phone service area. There are typically three methods through which to make mobile phone calls. These include the CDMA system, GSM systems and TDMA systems. With the advent of newer systems such as HSDPA, EDGE and other technology upgrades, today mobile cellular phones can be capable of making calls from even a major credit card terminal.

The CDMA system is the primary system used in the United States for mobile cellular phone use. It uses a demodulated sound signal, which is a digital representation of the voice data sent out by the mobile cellular phone user. In order for a call to be properly delivered, a bit rate must be negotiated with the local phone service company. The downside is that the bit rate is not constant and varies according to what networks the mobile cellular phone has been used with.

GSM stands for Global System for Mobile Communication. This system has a SIM card that allows a user to make mobile phone calls from a major credit card terminal using an appropriate connection. It also employs the EDGE technology, which is less reliable than CDMA and TDMA. This system can allow a signal to be generated, but is usually a weaker signal. Because of this, GSM is not widely used outside of the United States.

The third variety is the TDMA system, which was introduced in the United States in 1996. The TDMA system works on the same premise as CDMA, which operates on the same principal of allowing signals to be delivered when the signal is stronger than the cell phone reception. However, it does not employ the TDMA technology within the mobile cellular phone itself. As opposed to GSM, TDMA cell phones are not able to connect to other cell phones via their connections. There is no doubt that this type of mobile phone is ideal for individuals who live in rural areas, since most cell phone companies do not offer this service in densely populated areas.

Another type of mobile cellular phone is the ATM phone or AT&T phone. These phones use the GSM or Global System for Mobile Communication technology as well, but they also have their own SIM cards and allow connectivity to other GSM-enabled phones. They are not, however, widely available. This is because they are considered to be of higher quality than the others and they require the use of an additional sim card.

The mobile cellular phone is used for a multitude of purposes. Some of these are more for fun, while others are more practical, such as communication or safety features. Whatever the use, they are becoming more popular each day, especially with younger people. As the world becomes a smaller place, staying in touch with friends or family members is easier than ever.