“3G” stands for “Third Generation.” The distinction of the 3G mobile phone system is that it used sufficient capacity of digital transmission to allow Internet access at a rate comparable to that offered by broadband services over landlines. A 3G SIM will work in a non-3G phone as long as that phone uses the same network as the SIM and operates with digital signals.
The first generation of mobile phones transmitted and received analogue signals. This means that a 3G SIM would not work in a 1G phone, because 3G uses digital technology. The defining feature of 2G phones was that they used a digital signal. A smaller step exists between 2G and 3G technology. This is called EDGE and is often referred to as 2.5G. This is also a digital service and so a 3G SIM will work in 2.5G phones. The fourth generation of mobile phones emerged in 2010. This technology emulates the Internet’s method of data transmission by splitting all data into packets.
The switch from first generation to second generation did not allow for any backwards compatibility. The methods the two systems use are so different that the introduction of 2G represented a clear break. However, 3G uses the same underlying method as 2G. The International Telecommunication Union, which defines mobile transmission standards, specifically required that 3G devices should be compatible with 2G devices. This is because 3G services are not always available everywhere in the world. 3G phones were made to cope with 2G transmissions. Owners of 3G phones can turn off the phone’s 3G capabilities when not using it for Internet access to extend the battery charge, so 3G SIM cards are often expected to work as a 2G service. A similar requirement of backwards compatibility was also specified for 4G devices, which is why your 3G SIM will also work in a 4G phone.
Apart from generational considerations, the SIM card and the phone must both be designed to work with the same network. However, the likelihood of this is high because 79% of the western hemisphere uses the same mobile phone network -- which is GSM. GSM stands for “Global System for Mobile Communications” and has more than six billion subscribers in the world.
The dominance of GSM will end as the 4G rollout progresses. There is no unity of choice of network technology among network providers for the type of network they use. That means that your 3G SIM card will only work with certain 4G phones.
- 20 of the funniest online reviews ever
- 14 Biggest lies people tell in online dating sites
- Hilarious things Google thinks you're trying to search for