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page: [[Cellular technology]]
==Generations==
Significant advances in cellular technology are generally used to mark "generations" of the system.
===First generation (1G)===
First deployed in Tokyo in 1979, 1G cellular technology transmitted analogue audio signals using 150MHz and 900MHz bands. These mobile phones were bulky, and were initially used mostly in cars.
===Second generation (2G)===
2G cellular technology made a significant change to this system, by changing over to a fully digital audio stream. Among the benefits of this change was the new ability to send text messages, rather than just voice calls. These messages were limited to a size of 1120 bits, which 7 bits being used for each character. This resulted in the well-recognized message limit of 160 characters. When launched, 2G supported transfer speeds of up to 9.2kbps. It used the 1.8GHz and 900MHz bands.
==="2.5G"===
Although not a formal title, so-called "2.5G" offered significant improvements to the original 2G system. A new protocol called General Packet Radio Switching (GPRS) was responsible enabling speeds of up to 200kbps on 2G networks.
===Third Generation (3G)===
3G offered further performance improvements, with transfer speeds of 144kbps to 2Mbps. This used frequencies between 1.6GHz and 2.0GHz.
===(H+)===
===Fourth generation (4G)===
This generation utilizes frequencies between 2GHz and 8GHz, and offers speeds ranging from 100Mbps to 1Gbps.
===Fifth generation===