What is a cell phone and how does it work? Simply put, cell phones are hand held devices with keyboards that are powered by rechargeable batteries. A single line of code (that’s probably stored in your phone’s memory) allows the user to make and receive phone calls. In other words, the phone is a miniature computer complete with keypads, buttons, dialing numbers, and whatnot.
Cell phones work with radio waves, a type of electromagnetic energy found on the electromagnetic spectrum just below visible light. When a cell phone receives a signal, it amplifies the transmitted signal using a demodulation device. This allows a single cell phone to send and receive signals at a much higher bandwidth than could be achieved with the older analog signals. In other words, the signal strength of the cellular network is far greater than what a landline could provide. The strength of the signal increases as the distance from the cell phone tower increases. In other words, wherever you are, you can get good reception.
Most people associate cell phones with long-distance calling because it’s the only practical way to utilize cellular technology to communicate over great distances. There is another advantage to using mobile phone services beyond long distance communication; this is the ability to use the same type of signals for email and other Internet applications as well. Many of the old-style landlines used radio frequencies to communicate; this meant that each time you refreshed your page or sent a message, your computer would also have to re-download the newest data.
The problem with this is that every time your computer refreshed the page, it had to also download new radio wave data, thus slowing everything down. This makes it very difficult to do things like send email or browse the Internet. Luckily, in the last few years, cell phones have started using something called GSM, which stands for Global System for Mobile Communication. This technology allows mobile phones to transmit radio waves instead of radio frequency waves, thus increasing overall communication speed, allowing users to access email and other applications more quickly.
How is this accomplished? Basically, these radios broadcast a code that is readable by nearby mobile devices. This basic form of GSM uses a triangulating algorithm to figure out which of two numbers is the closest to the user’s number that also falls within the service provider’s area. Once the service provider and the user have agreed to use this system, all they need to do is select a code to call that has been preloaded into the phone, and then place the phone next to their ear.
Modern cell phones are equipped with much larger antenna arrays than were traditionally used, usually around the outside of the device, or even inside. These antennas are typically made from some type of semiconductor, such as silicon carbide or gallium arsenide. Silicon carbide and gallium arsenide are the most commonly used materials, but other types of semiconductors are sometimes used, depending on the manufacturer and the application. The antennas are actually connected to an amplifier, which transfers the electrical energy from the signals to the circuits within the phone, amplifying the signal and allowing it to be dialed into the appropriate frequency.
The amount of electrical energy transmitted through any given antenna will vary, depending on the strength of the antenna as well as various other factors such as the atmospheric pressure, the temperature of the surrounding air, and other factors. In some cases, the signal strength may drop when the antenna is subjected to increased atmospheric pressure, resulting in lower bandwidth. In other cases, there may be an unnatural frequency component to the signal, which is called ” spurious emission” and has the potential to cause problems for the phone user. Wireless phones use their own antenna to receive the radio signal, rather than relying on the antenna on the phone tower. This allows them to circumvent some of the drawbacks inherent in older portable phones.
Cell phones using wireless technology are distinguished from “normal” phones by the presence of a separate transmission device, called the cellular network (ISP). The ISP transmits these signals to base stations, which handle the call and handle reception. The base stations receive signals from various cells via their antennas, and then translates these signals into voice frequencies that are ultimately sent to the user’s phone.