The three different types of GSM are RAN (radio access network), core network, and mobile switching center (MSC). The RAN includes the base station (BSC), Mobile Switching Centre (MSC), and Home Location Register. The two types of networks differ slightly in their functions and communication protocols. Both mobile operators and GSM network operators have roaming agreements with foreign operators. If you’re traveling abroad and need to make calls in a foreign country, it’s possible to switch your SIM card to metered local access (MLA), which can help you reduce the costs associated with roaming.
FDMA is the most common type of GSM. In FDMA, a single carrier frequency is divided into 124 bits, the first four of which act as parity bits. This data block is then spaced out across the two bands, with the first four blocks of 57 bits serving as a guard band between GSM and other services. TDMA, on the other hand, divides each carrier frequency into eight bursts of two or four bits. This creates more data, but the interleaving process makes it easier to correct errors.
UTRAN used the core network from GERAN, but added several components to support the different types of cellular service. It included interfaces that allowed for both packet and circuit-switched access. It represented a major paradigm shift in the way mobile terminals operated. The first two types of GSM used the A interface, while UTRAN was designed to handle both. The second type, GSM, uses the UTRAN interface to support packet and circuit-switched connections.
NSS manages communications between mobile and fixed users. This includes data bases on subscribers and mobility management. MSC is the switch of the network and performs switching functions. It also provides connections to other networks. A gateway acts as an interface between the mobile cellular network and the PSTN. The GMSC routes calls from the fixed network to the GSM user. These are the three major types of GSM.
Lastly, the GSM standard supports supplementary services. These services are revenue-generating features that supplement telephony services. Call waiting and call hold are two of the most common supplementary services. Call waiting lets the caller know that there is an incoming call. These services are available to both subscribers and operators. All GSM telecommunications systems support call waiting and multiparty service. The latter two types allow you to communicate with up to six people at the same time.
The GSM standard is a digital technology that has made cellular networks possible. Its specifications were designed to be compatible with the ISDN network. The digital technology also allows for future improvements and changes to the characteristics of the GSM system. They were standardized in 1989 by the European Telecommunications Standards Institute. The result was a high level of compatibility among the different types of GSM. They are a common and vital part of cellular communication.