GSM is a digital mobile telephone system widely used in Europe and other parts of the world. GSM uses a variant of time division multiple access (TDMA) and is the most widely used of the three digital wireless telephony technologies (TDMA, GSM, and CDMA). GSM digitizes and compresses the data, then sends it along a channel with two other streams of user data, each in its own time slot. It works on the 900 MHz or 1800 MHz frequency band. A GSM network consists of the following components: Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get Original EssayA mobile station: It is the mobile phone which consists of the transceiver, display and processor and is controlled by a SIM card which works on the network.Base station subsystem: It acts as an interface between the mobile station and the network subsystem . It consists of the Transceiver Base Station which contains the radio transceivers and manages the communication protocols with mobile phones. It also consists of the base station controller which controls the base transceiver station and serves as the interface between the mobile station and the mobile switching center. Network Subsystem: Provides basic network connection to mobile stations. The key part of the network subsystem is the mobile service switching center which provides access to different networks such as ISDN, PSTN etc. It also consists of the home location log and the visitor location log which provides the call routing and roaming capabilities of GSM. It also contains the Equipment Identity Register which maintains an account of all mobile equipment where each mobile is identified by its IMEI number. IMEI stands for International Mobile Equipment Identity. GSM module features: Improved spectrum efficiency International roaming Integrated services digital network (ISDN) compatibility Support for new services SIM directory management Fixed dial number (FDN) Real-time clock with phone management alarmsHigh quality speechUses encryption to make more secure phone callsShort message service (SMS)Base Station Subsystem (BSS) The Base Station Subsystem (BSS) section of the GSM network architecture that is fundamentally associated with communication with mobile phones on the network. It consists of two elements: Base transceiver station (BTS): the BTS used in a GSM network includes radio transmitter receivers and their associated antennas that transmit and receive to communicate directly with mobile phones. The BTS is the element that defines each cell. The BTS communicates with cell phones and the interface between the two is known as the Um interface with its associated protocols. Base Station Controller (BSC): The BSC is the next stage in the GSM network. He controls a group of BTS and is often co-located with one of the BTS in his group. It manages radio resources and controls things like handover within BTS's group, allocates channels, and the like. It communicates with BTS via what is called the Abis interface. Network Switching Subsystem (NSS) The GSM system architecture contains a variety of different elements and is often referred to as the core network. It provides the main control and interface for the entire mobile network. The main elements within the core network include: Mobile Services Switching Center (MSC): The main element within the core network area of ​​the overall GSM network architecture is the Mobile Switching Services Center ( MSC). The MSC acts as a normal switching node within a PSTN or ISDN network, but also provides additional functionality to meet a user's needs..