A mobile phone, short for mobile phone or cell phone, sometimes shortened to just cell or just mobile phone, is generally a small portable phone that will make and receive telephone calls over a wireless telephone network while the user is traveling within an interexchange area. Many countries around the world have developed a comprehensive public switched telephone network or PSTN system which provides telephone service to nearly all of their citizenry. This service has become quite expensive in recent years as more people move out to cities or rural areas where there is no public switched telephone network. The public switched telephone network is being replaced by a mobile or cell phone service which is more economical and more reliable than the older PSTN system.
There are several different types of mobile phones and they are differentiated by their base frequency as well as their overall size, design and other factors. Basic hand held phones that have a keyboard on the front and a touch screen are categorized as PDAs (personal digital assistants), smart phones or mini laptops. These phones generally run on either a single or two gSM channels and can be placed in one ear or both. These phones are very small and are capable of storing only a small amount of information and can be placed easily in one ear.
Next, there are Walkman phones which have three main components: a built-in receiver for reception and transmission, a speaker with adjustable sound levels, and an amplifier for power and signal processing. Handheld devices such as the Walkman also have a miniature CD player with two ears, although these types of cellular systems are not true walkman phones in the true sense of the word since they lack an amplifier. These devices can hold about thirty songs and can detect music from at least nine different audio channels. Mobile phones with a cellular system such as these are often referred to as Pocket PCs. Mobile phones with cellular systems such as these are sometimes marketed as Pocket PC’s since the device itself is essentially a handheld personal computer.
Next, we come to the Mini PC or the Micro PC. The Mini PC was designed specifically to function as a portable work station with the ability to access the Internet. This type of mobile phone has the ability to access both the Internet and a host of other features, most importantly, the MTSO (Mobile Telephone System). The MTSO works in conjunction with the PC to allow data to be exchanged between the computer and the handheld receiver.
Mobile phones used for business purposes typically have the ability to send and receive calls and text messages. Some of these mobile phones used for business use even have the ability to play videos and to play music CDs. Most of these mobile phones used for business purposes have the ability to work in a variety of different data transmission formats such as GPRS, EDGE and PCMC.
As far as the Cellular Systems go, there are two types of frequencies that these mobile phone companies will sell you. There is the base frequency, which is the most commonly used, and then there is the USB based frequency. The USB based frequency can work in conjunction with other telephone systems and will allow the use of alternate frequencies between the computer and the handheld. The advantage of using a combination of base and USB based frequencies is that if the primary frequency is interrupted or changed by an active signal from another source, the frequency used by the other source will continue operating normally.