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May 30, 2024

What is a Cellular Device?

A cellular device is any handheld wireless phone that operates on the radio frequencies of a mobile network. A cellular phone can make and receive calls while the user is moving within a service area, unlike a landline telephone that requires a wired connection to a phone company's central office to work. Cellular devices can also connect to the Internet over Wi-Fi or a cellular network, which allows them to send and receive large amounts of data like emails, movies and music, as well as perform e-book reading and Web browsing. A smartphone is a more powerful cellular phone that can run complex apps and provide advanced features beyond simple calling, voicemail and text messaging.

The first handheld cellular phones were developed by engineers at Motorola in the early 1970s and used analog technology. The first commercially available cellphone was introduced in 1983 and called the Motorola DynaTAC 8000x, which cost $3,995. Since then, there have been several upgrades to the basic features of mobile communications.

A cell phone uses a radio frequency to transmit data, including call and SMS messages, between a base station and the handset. These radio frequencies are on the electromagnetic spectrum between FM radio waves and the microwave oven waves used by radar and satellite stations. Each cellular system is divided into areas, called cells, that are supposed to be uniform but frequently overlap. Each cell has a central base station and two sets of assigned transmission channels; one set is used by the base station, and the other by handsets. When a phone moves into a new cell, the phone's antenna listens for a specific identification signal (SID) on a control channel and then signals the handset to switch to its assigned frequencies.

As demand for mobile communication services increased, more and more base stations were installed in cities to increase capacity. The next big advance came with the implementation of digital cellular systems, which allow a single frequency to host multiple simultaneous calls. This required sophisticated modulation and encoding techniques to convert the analog signal from the base station into digital information that can be transmitted over the air to the handset.

These systems also use short-range Wi-Fi infrastructure to offload data from the cellular network, reducing strain on the mobile transmission networks. The introduction of 3G, or third generation cellular communications, in 2001 ushered in faster and more flexible data services, such as mobile broadband connections capable of downloading large e-mail messages, sending high-definition video and watching online television and movies.

In addition to speedy data transfers, 3G technology supports voice calls in stereo, which makes it easier for people to converse while walking down the street or driving a car. The 4G, or fourth generation, standard will support even more advanced multimedia services. For example, wireless service providers will likely team up with music and movie rights holders to offer downloads of songs and videos directly to smartphones, bypassing traditional cellular networks.