2G mobile telephony

The second generation of mobile telephony is known as 2G mobile telephony. It is characterized by being digital and reducing the size to improve portability. 2G mobile telephony is not a standard or a protocol, but rather a way of marking the change from analog to digital mobile telephony protocols.

The arrival of the second generation of mobile telephony was around 1990 and its development derives from the need to be able to have better call handling in practically the same radio frequency spectrums assigned to mobile telephony, for this purpose protocols were introduced digital telephony that, in addition to allowing more simultaneous links in the same bandwidth, allowed the integration of other services, which were previously independent, in the same signal, such as sending text messages or pages in a service called Short Message Service (SMS) and a greater capacity to send data from fax and modem devices.

2G encompasses several different protocols developed by various companies and incompatible with each other, which limited the area of use of mobile phones to regions with carriers that support them.

In Mexico, the 2G network of the operator Movistar was completely turned off on January 1, 2021. Its use is not possible from that date.

2G telephony protocols

• GSM (Global System for Mobile Communications).
• Cellular PCS/IS-136, known as TDMA (also known as TIA/EIA136 or ANSI-136) System regulated by the Telecommunications Industry Association (or TIA).
• IS-95/cdmaONE, known as CDMA (Code Division Multiple Access).
• D-AMPS (Digital Advanced Mobile Phone System).
• PHS (Personal Handy-phone System) System used at first in Japan by the company NTT DoCoMo in order to have a standard focused more on data transfer than the rest of the 2G standards.

2.5G / 2.75G telephony

As such, there is no standard or technology that can be called 2.5G or 2.75G, but some 2G mobile phones that incorporate some of the improvements and technologies of the 3G standard are usually called that, such as GPRS and EDGE on 3G networks and with data rates higher than regular 2G phones but lower than 3G.

Although until now a new generation of mobile phones has coexisted with its predecessor technology (only the first analog generation has disappeared), the arrival of 5G will mean the disappearance of 2G and 3G networks to use the spectrum they occupy. While there are features that allow spectrum to be shared between technologies (spectrum sharing), we must keep in mind that 2G/3G networks will eventually shut down.