Cellular technology
Cellular technology is a term used to describe the basic cell tower and radio cells technology behind all wireless phones regardless of the specific communications protocol they use, such as GSM, CDMA, or TDMA.
This term derives from the cell-like design of the system's base stations that receive and transmit calls. Both cellular and PCS phones use cellular technology.
Contents
Generations
Significant advances in cellular technology are generally used to mark "generations" of the system.
First generation
First deployed in Tokyo in 1979, what could now be called "1G" cellular technology transmitted analogue audio signals using 150MHz and 900MHz bands. These mobile phones were bulky, and were initially used mostly in cars.
General Packet Radio Service (2G)
2G cellular technology made a significant change to this system, by changing over to a fully digital audio stream. A new protocol called General Packet Radio Switching (GPRS) was responsible for these improvements on 2G networks. 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.[1]
Edge ("2.5G")
Edge offered significant improvements to the original 2G system.[1] IT was generally considered to offer downlaod speeds of about 400 kbit/s but in ideal conditions, it could reach 1 Mbit/s.[2]
Third Generation (3G)
3G offered further performance improvements, with transfer speeds of about 384 kbit/s. However, depending on how it was implemented, speeds could go much higher.[2] This used frequencies between 1.6GHz and 2.0GHz.
HSDPA ("3.5G")
HSDPA (typically bearing the flag of "H") offered significant download speed improvements over 3G. It's maximum sppeds differed greatly depening on numerous factors, but reports indicate it ran somewhere between 7.2 Mb/s download,[1] and 14 Mbit/s for download and 5.76 Mbit/s for upload.[2]
HDSDPA+ ("3.75G")
HDSDPA+ (typically bearing the flag of "H+") offered another download speed increase over 3G, at 21 Mb/s.[1]
LTE/4G (4G)
This generation utilizes frequencies between 2GHz and 8GHz, and offers speeds of up to 150 Mb/s.[1]
LTE-A/4G+ (4G+)
LTE-A/4G+ (typically bearing the flag of "4G+") doubled theoretical download speeds, at a new maximum of 300 Mb/s.[1]
Fifth generation
Please see the main article on this topic here
5G offers theoretical download speeds of over 1000 Mb/s. This requires a connection to one of the network's small base stations, running in a high-frequency band.[1]
