GSM vs 3G Network Technology
GSM (Global System for Mobile Communication) and 3G (3rd Generation mobile technology) are both mobile communication technologies that have been evolved over the time. GSM was introduced as a standard in 1989 while 3G was proposed by 3GPP (3rd Generation Partnership Project) in year 2000.GSM and 3G uses different multiple access technologies for mobile stations to access the network, which also introduced architectural changes in the network as well.
In general, GSM, considered as a (2G) 2nd Generation mobile technology is based on the digital cellular technology. GSM was the most popular 2G technology when compared with other 2G technologies introduced in the same decade, like IS-95 in North America and PDC (Personal Digital Communication) in Japan. After founding of the ETSI (European Telecommunication Standard Institute) in 1989, GSM became the popular technical standard in most countries. GSM air interface uses separate time slots in separate frequency channels for each user, so that, there will be less interference between two separate users accessing the network. GSM reuses same frequency channels in non-concentric cells so that inter cell interference is mitigated between neighbour cells. Circuit switched data rate supported in GSM is 14.4 kbps.
3G is based on the IMT-2000 (International Mobile Telecommunication) specifications published by International Telecommunication Union. Different 3G technologies evolved from different continents and European standard was called as W-CDMA (Wideband – Code Division Multiple Access), North American one is called as cdma2000 while TD-SCDMA (Time Division – Synchronous CDMA) standard was used by China. Currently, 3GPP released different versions of 3G standardisations with the release numbers R99, R4, R5, R6 and R7. 3GPP release 8 and 9 are considered as 4th Generation Technologies which leads to LTE (Long Term Evolution). 3G technologies such as WCDMA and cdma2000 use Frequency Division Duplexing while TD-SCDMA uses Time Division Duplexing. Telecommunication systems should deliver peak data rates of up to 200kbps to comply with the IMT-2000 standard whereas as per the 3GPP R99 standard peak data rates should be 384kbps.
GSM vs 3G
When comparing GSM and 3G technologies, 3G allows much higher data rates (bandwidth) to the end user than the GSM. Also, 3G technologies uses packet switched technology for data while GSM uses circuit switched data.
Multiple access method used in GSM is TDMA (Time Division Multiple Access) and FDMA (Frequency Division Multiple Access), whereas, in 3G it is WCDMA. Therefore in 3G each user spread its signal in entire bandwidth, so that, other users see it as pseudo white noise (WCDMA) whereas, in GSM, each user select separate frequency channel and separate time slot in that channel to communicate. GSM is considered as a 2nd Generation technology while 3G is the 3rd Generation latest technologies standardized by 3GPP.
When comparing the architecture, 3G introduced new nodes called Node-B and RNC (Radio Network Controller) to replace the existing BTS (Base Transceiver Station) and BSC (Base Station Controller) respectively. These architectural changes forced most of the mobile operators to invest again (less opportunities to upgrade) in 3G technology on top of the existing GSM network, because of the incompatibility of technologies. Also, mobile devices are evolved to support both technologies simply because of above reason.
One of the most important goals of evolving from GSM to 3G, is the powerful and efficient mobile access to the internet. 3G offers higher data rates when compared with GSM by the efficient use of the existing spectrum which is considered as a scares resource in most countries. Even though, 3G compelled higher investment from the mobile operators, it has given a considerably higher data rates which cannot be delivered with GSM.