The development of digital mobile communications in Germany
Nowadays, mobile communications is a widely used technology. The opening up of the telephone market in Germany and the development of ever more affordable mobile phones have led to a boom in the mobile communications sector. In 2006, the number of mobile phones in Germany has overtaken the number of inhabitants. In 2010, there were 107 million subscriptions for 82 million people. Today, more than one in ten households or over nine percent of German households use a mobile phone instead of a landline.
The history of mobile communications goes back to the first half of the 20th century. Even before the launch of the so-called ‘A network’ at the end of the 1950s, mobile telephony was available in Germany.
As early as 1918, the German National Railway, the Deutsche Reichsbahn, carried out the first experiments with mobile telephony. In 1926, first class rail passengers on the route between Berlin and Hamburg could make calls from the moving train for the first time. The first real mobile service in Germany was the maritime mobile service. Further mobile network services, such as port, train and city services were set up during the 1950s. Most of them used long-wave and later medium-wave bands.
The A network
In 1958 the Federal Post Office merged all the existing networks to create the “public land mobile network A” („Öffentliches, bewegtes Landfunknetz (öbL) A“). This was the launch of the first national mobile phone network – the A network. At the end of the 1950s, the A network was the largest public mobile phone network worldwide. In 1968, it covered about 80 % of the country, which meant that on four-fifths of West Germany’s territory it was possible to make mobile calls.
Mobile telephony, however, remained an exclusive communication technology. The A network had only about 10,500 subscribers due to the high costs of terminal devices and services. A “standard device” alone cost between 8,000 and 15,000 German marks, with a basic charge of up to 270 marks per month. By comparison, a brand-new Volkswagen Beetle at that time cost about 5,000 marks. Additionally, at a weighty 16 kilograms, terminals were extremely heavy compared with today.
The B network
The A network was followed by the B network in 1972. Users of this new mobile network no longer had to rely on the operator to connect them manually. Instead, they could dial themselves if they could assign the location of the party they wished to call to the corresponding zone. The 150 zones that existed in West Germany reached a diameter of up to 150 kilometres. The B network for the first time also allowed customers to make calls abroad, in the Netherlands, Austria and Luxembourg.
Although mobile telephony remained expensive, even with the B network, the number of subscribers grew quickly towards the end of the 1970s. This growth meant that network operators had to use additional frequencies from the A network that had been discontinued in 1977. In 1986, when there was no further capacity in the network, no new subscribers were accepted. By this time, the number of subscribers had almost reached 27,000. By now, the new and modern C network had become available and the B network was finally closed in 1994.
The C network
The new C network was launched on 1 September 1985. It transmitted at a radio frequency of 450 megahertz and was the first digital – at least partially – mobile network in Germany. Speech was transmitted via analogous radio technology, just as in the A and B network, but switching and control information were already digital.
This meant that the location of each subscriber could now be determined automatically – this was the prerequisite for the introduction of a single dialling code (0161). All C network subscribers in the whole of West Germany could now be reached with this code. For the first time, the network was also able to deal with handovers: the transfer of calls when the mobile phone user moved from one radio cell to the next during a call.
The C network marked the transition from car phones to portable mobile phones but devices were still considerably larger than today’s mobile phones. The monthly service charge for the C network fell from 120 marks to only 19 marks. The C network at times almost reached its capacity limit, with up to 800,000 subscribers, and its operation was terminated in 2000.
In mid 1992, Germany entered the age of the digital “Global System for Mobile Communication” (GSM). This second-generation mobile telephone technology (2G) comprised the D and E mobile networks. The A, B and C networks together are considered the first generation.
The D and E mobile networks made mobile communication accessible to the general public in the 1990s. For the first time, mobile phones were small and handy (hence the German term “Handy” for a mobile phone). As GSM technology developed further, it provided good quality speech transmission, data services such as text messages, fax or notebook-PC connections and even mobile internet access with a low transmission rate. The huge success of the second-generation networks led to almost complete network coverage.
Tests on the D network started in July 1991 and in the summer of 1992 it went into service. At that time, only a few terminal devices were available. The first calls were made from 8 watt fixed car phones; mobile devices appeared for the first time in autumn 1992.
In the summer of 1994, the first GSM 1800 network (E1) was launched in Germany. GSM 1800 is a variation of the GSM 900 mobile phone standard that transmits in the 1710 to 1880 MHz frequency range. In October 1998 a second E network was launched in Germany.
From the mid 1990s on it was possible to send faxes via GSM networks and to transmit data via mobile phones. 1995 saw the test run of the Short Message Service (SMS) that allowed the digital transmission of text messages. Within a very short time, this service developed into the most-used service for mobile phones after telephony. Mobile phone rates were reduced considerably. In 1996 the basic charge dropped from 50 marks to about 30 marks. Prepaid cards were introduced the following year. At the end of the 1990s, the enhanced full rate was introduced – a speech coding standard that improved the quality of speech transmission by eliminating technical defects.
GPRS: Data goes mobile
Now data followed speech and went mobile. This became possible with the introduction of the “General Packet Radio Service” (GPRS), which separated data communication from speech communication. This technology permitted the creation of direct interfaces to the internet, which accelerated data streams enormously. GPRS divides digitized data into small packets that are all provided with the exact address of the recipient. These packets are sent to the recipient via any available capacity on the mobile network and all the packets destined for this recipient can only be reassembled and decoded once they arrive. This technology is similar to the transmission technology used by the internet. It makes better use of capacities and is therefore able to increase transmission speed.
The third-generation mobile telephone technology (3G) of UMTS introduced a completely new technology. It required the development of independent UMTS networks and the design of new mobile phones that could use UMTS in addition to GSM.
UMTS is comparable to GPRS in some aspects; it differs by transmitting speech, as well as data, in packets. UMTS is therefore also called broadband technology, which merely means that a very broad frequency range is available for data and speech.
To give a visual example: If the frequency ranges were roads, a GSM mobile network connection would always need one entire lane (frequency) between sender and recipient. This is not necessary for UMTS. Here, the data packets “slide” along beside each other in a disorderly fashion, taking the fastest way to their target. Once they have reached their destination, they are sorted, decoded and reassembled into speech or data. Coding ensures that everyone can only decode the data intended for them. This procedure is efficient and fast. The only disadvantage is that delays ensue if too many packets use the “slide” at the same time.
The data capacity of UMTS of up to 384 kbit per second opens up new opportunities: video conferences, TV programmes and downloading data from the internet transform the mobile phone into a digital mobile information medium. UMTS allows speech and data to be transmitted at the same time. This makes it possible to make calls while surfing the internet or writing or receiving emails.
As smart phones, tablet PCs and new types of applications expand the use of the mobile internet, demand is rising for even faster and more powerful transmission. Technical developments in the UMTS networks, such as HSDPA (High Speed Downlink Packet Access), now allow a transmission rate of up to 7.2 mbit/s.
The development of LTE not only focused on further increasing bit rates but also on developing a worldwide standard. International committees discussed numerous options and in September 2006 a simulated LTE connection with live applications was presented for the first time. Two months later, the first public demonstration of LTE took place in Hong Kong.
Scandinavia leads the way
First commercial LTE networks were launched at the end of 2009 in Stockholm and Oslo. LTE reached Germany in May 2010 when the Federal Network Agency auctioned the LTE frequency bands.
Digital dividend benefits rural areas
LTE technology will specifically be used to supply rural areas with fast broadband internet via mobile phone networks. The 800 MHz frequency range that was freed-up when broadcasting was digitized (the so-called “digital dividend”) has excellent physical propagation properties. Individual base stations can serve large areas. This frequency range is therefore especially well suited to providing wireless broadband to sparsely populated areas.
The Federal Network Agency has developed clear rules for the development of the LTE network. Municipalities without broadband connection (“white spaces”) and with fewer than 5,000 inhabitants have top priority. More densely populated areas can only follow once 90 percent of these municipalities in each Federal State have been connected. This will ensure that all white spaces will soon disappear from Germany’s broadband map.