User:DavidB4/workspace
The following is personal workspace. Once content is ready, I will migrate it to the appropriate location. I may use this for any number of purposes, but generally it will be used for drafts.
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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.