Cellular network

The term wireless network is the technical infrastructure on which occurs the transmission of signals for mobile communication. The mobile network essentially comprises the mobile switching network, which hosts the transmission and switching of signals between the fixed facilities and platforms of the mobile network and the access network, where the transmission of signals between a mobile radio antenna and the mobile phone ( colloquially phone ) takes place; the access network is also referred to as air interface.

Proliferation of mobile networks

In Germany currently operates four mobile networks. The oldest still operating networks are the D-net and the E-net, which were introduced in Germany in 1991 and 1993 and based on the GSM standard. At this time, the voice transmission, the most common form. However, the mid-90s won the data transmission in importance and made ​​the modernization of GSM. For this purpose, the GPRS standard has been developed and introduced. Here, the mobile switching network is extended to include the ability for packet-oriented data transmission, the radio network but not changed. The introduction of data- optimized 3G networks ultimately aims to increase data transmission rates and also eliminates capacity problems in voice transmission. Advanced functions, such as multimedia, follow the expansion of 3G networks. The most important standard is the 3G Universal Mobile Telecommunications System ( UMTS). With the launch of " smartphones ", reinforced support data applications, continued to increase the capacity of the networks, resulting in the development of the Long Term Evolution standards (LTE ) led. LTE uses only data transmission and differs from the older networks which also use circuit switching.

In Switzerland mobile networks operated since 1993.

→ Main article: History of mobile networks in Switzerland

Construction

Mobile networks are divided as the fixed network in a core and multiple access networks. The function of the core network is the connection of the individual access networks, which allow the end users to access the network. The distinction between mobile and fixed network consists mainly in the access network that builds wireless communication links in wireless networks, thus ensuring the movement of participants. The access networks are wireless networks in general and are often referred to by their English term, Radio Access Network (RAN ). Depending on the standard there are also other components and subnets, which will ensure the provision of the services.

Global System for Mobile Communications (GSM)

→ Main article: Architecture of GSM network

The separation adopted from the landline is most pronounced in the GSM system. The base station subsystem (BSS), which consists of the base stations, provides all of the functions that are necessary for the connection between the network and mobile stations, and so corresponds to the traditional access network. The Network Subsystem (NSS ) then coordinates the BSS. It contains all the components for the switching of telephone calls and therefore corresponds to the core network. The third component of the architecture is the Intelligent Network Subsystem (IN), which contains databases that provide additional services. This includes, for example, the administration of pre-paid services.

General Packet Radio Service (GPRS)

→ Main article: network architecture of GPRS

GPRS GSM expands the ability of the data transmission. Both systems use the same base stations, so that no changes were made in the access network with the exception of a software update. The core network was, however, extended to include the ability to build a packet-switched communication links forming. This allows for flexible bandwidth and thus improving the efficiency of the transmission capacity of the channels. For this purpose, the network, the Packet Control Unit (PCU ) for the reservation of time slots in the base station, the Serving GPRS Support Node (SGSN) for routing of data packets between the radio network and the gateway GPRS support node (GGSN ) for connecting the mobile radio network Added to the Internet.

Universal Mobile Telecommunications System (UMTS )

→ Main article: Network architecture of UMTS

UMTS represents the evolution of the GSM / GPRS architecture and was designed from the outset for data transmission. At the beginning of the core network was hardly changed and adjusted only by means of software update. However, the structure of the access network is a newly developed UMTS Terrestrial Radio Acces Network ( UTRAN) is called.

UTRAN is used in contrast to the GSM / GPRS no division multiplex for data transmission, but assigns the signals on individual codes to the subscribers. Later, new architectures, such as the Bearer Independent Core Network ( BICN ) have been developed and implemented in the core network, who led the previously separate transmission of voice and data connections together into a common IP-based transmission methods.

Long Term Evolution ( LTE)

→ Main article: network architecture of LTE

In LTE, the classical method of signal transmission have been completely replaced by packet switching and data transmission. One of these separate voice no longer exists. At the same time, the hierarchical structure has been flattened. The actual traffic is by joining and core network only passed, support services, such as mobility management or paging will be taken over by the Mobility Management Entity, which communicates both with the interconnection network called LTE evolved UTRAN ( EUTRAN ), as well as the core network.

Technical operations in mobile networks

Mobile networks are attributable to the communications networks and are primarily for message transmission. Due to the mobility of the subscriber, the signal transmission compared to other networks such as the landline is difficult. Therefore, there are some specific processes to enable the mobile communication. These include the transmission over the air interface, the mobility management, paging, or handover. Depending on the architecture and art, these functions are provided by other modules and is partially organized differently (→ see the sections on the architectures above).

Security

In case of failure of a network are often affected many people. The following are some major mobile network failures are listed in Germany:

Plans to switch off the mobile radio

The police should be able to require in Saxony-Anhalt from any service provider to prevent the communication links, if this is necessary to avert an imminent danger to the existence or security of the Federation or of a country or to life, limb or liberty of a person.