GSM
or Global System for Mobile Communications
is a standard and infrastructure used for mobile phone communication. GSM is a standard which is created by the European Telecommunications Standards Institute
(ETSI). It is also called as second-generation or 2G.
GSM History
GSM has a history of about 29 years where it is first deployed in Finland in December 1991 and became a global standard in 2010 with %90 market shares and implementation over 193 countries.
- In 1983 the standard of the standard development with the name of Groupe Special Mobile.
- In 1987, 13 European countries signed to deploy and operate a common cellular telephone system across Europe which is the GSM standard.
- With its open and unified form, GSM is then deployed in the USA.
- In 1986 the 900 MHz band is reserved to be used for the GSM standard and deployment.
- The first GSM call made by Finnish prime minister Harri Holkeri on July 1 1991 where the network was built by Nokia and Siemens.
- In 1993 the 1800MHz is used for GSM in the UK.
- In 1995 fax, data, and SMS messaging services were launched commercially.
- Worldwide GSM subscribers passed 100 million in 1998.
- GPRS (internet access) first launched in 2000 commercially.
- GSM usage exceeded 1 billion in 2004.
- HSPA or High-Speed Packet Access technology provided for GSM users to connect the internet with high speeds.
- The GSM subscribers exceeded 3 billion in 2008.
- Counties like Australia, United Stated, Singapore started to shutdown GSM or 2G networks with the popularity of the new generation mobile networks like 3G and 4G in 2016.
GSM Architecture and Components
GSM consist of a complex architecture with multiple components. Followin picture depicts a genetic GSM architecture with different components like Mobile Equipment, SIM, BTS MSC etc.

Mobile Station
or MB
consist of multiple components like User Equipment
,SIM Card
, Mobile Equipment
.
Mobile Equipment
is the mobile devices which is generally a mobile phone but alternatively a table ot laptop.
SIM
is the SIM card which is used to connect the GSM network BTS.
Base Transceiver Station
or BTS
is the first hop to connect a GSM network which is located densly to provide the GSM network to the Mobile stations or mobile phones.
Base Station Controller
is the second hop whre BTS connected to the core phone network.
GPRS
is used to provide internet access for the GMS network for the Mobile stations.

GSM vs CDMA
GSM and CDMA generally compared with each other. Both are used to connect mobile devices into a mobile phone network with internet connection. Below we will compare similarities and diffrencies between these two standards GSM and CDMA.
- GSM is called as 2nd generation or 2G where CDMA is called as 3rd generation or 3G.
- GSM provides lower internet connection speed where CDMA provides higher internet connection speeds.
- In GSM standard the mobile phone number is linked into SIM card where in CDMA standard mobile phone number is embedded into the mobile phone.
- GSM standard provides better international roaming where CDMA is less flexible for roaming in different countries.
- Network covarage is the same for both GSM and CDMA standard which is mainly realted with the BTS count and density. But GSM is mostly vanished by the mobile phone network operators.