B-Netz
Encyclopedia
B-Netz was an analog
, commercial mobile radio telephone network that operated by the Deutsche Bundespost
in Germany
(at first only West Germany
) from 1972 until 1994. The system was also implemented in neighboring countries Austria
, The Netherlands and Luxembourg
. The B refers to the fact that it was the country's second public mobile telephone network, following the A-Netz.
As opposed to its predecessor, it featured direct-dialing (so that human operators were not required to connect calls). The frequency plan originally included only 38 channels
(with one call possible per frequency
channel), but it was upgraded to incorporate the A-Netz frequencies when that network was retired in 1980. The upgraded network had 78 channels and is sometimes referred to as the B2-Netz.
A major limitation of system was that, in order to reach a subscriber, one had to know his location since the handset
would assume the local area code
of the base station serving it. Handoff was not possible and calls were dropped when switched cells. Roaming
was possible between the implementing countries.
At its height in 1986, the network had 158 base station
s and about 27,000 subscribers in Germany and 1,770 in Austria
. At the end of 1988, there were 1,078 participants in West Berlin
alone. The network was vastly oversubscribed
and finding an available channel could prove difficult.
The connection between base station and handset unencrypted
, so eavesdropping
was easy and common. In rare cases, additional devices were added by both participants to encrypt conversations (such as discussions of important politicians).
The B-Netz would eventually be superseded by the technically superior C-Netz
, which was put into operation on May 1, 1985.
Analog signal
An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...
, commercial mobile radio telephone network that operated by the Deutsche Bundespost
Deutsche Bundespost
The Deutsche Bundespost was created in 1947 as a successor to the Reichspost . Between 1947 and 1950 the enterprise was called Deutsche Post...
in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
(at first only West Germany
West Germany
West Germany is the common English, but not official, name for the Federal Republic of Germany or FRG in the period between its creation in May 1949 to German reunification on 3 October 1990....
) from 1972 until 1994. The system was also implemented in neighboring countries Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...
, The Netherlands and Luxembourg
Luxembourg
Luxembourg , officially the Grand Duchy of Luxembourg , is a landlocked country in western Europe, bordered by Belgium, France, and Germany. It has two principal regions: the Oesling in the North as part of the Ardennes massif, and the Gutland in the south...
. The B refers to the fact that it was the country's second public mobile telephone network, following the A-Netz.
As opposed to its predecessor, it featured direct-dialing (so that human operators were not required to connect calls). The frequency plan originally included only 38 channels
Channel (communications)
In telecommunications and computer networking, a communication channel, or channel, refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel...
(with one call possible per frequency
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
channel), but it was upgraded to incorporate the A-Netz frequencies when that network was retired in 1980. The upgraded network had 78 channels and is sometimes referred to as the B2-Netz.
A major limitation of system was that, in order to reach a subscriber, one had to know his location since the handset
Handset
On a telephone, the handset is a device the user holds to the ear to hear the audio sound. Modern-day handsets usually contain the phone's microphone as well, but in early telephones the microphone was mounted directly on the telephone itself, which often was attached to a wall at a convenient...
would assume the local area code
Telephone numbering plan
A telephone numbering plan is a type of numbering scheme used in telecommunications to allocate telephone numbers to subscribers and to route telephone calls in a telephone network. A closed numbering plan, such as found in North America, imposes a fixed total length to numbers...
of the base station serving it. Handoff was not possible and calls were dropped when switched cells. Roaming
Roaming
In wireless telecommunications, roaming is a general term referring to the extension of connectivity service in a location that is different from the home location where the service was registered. Roaming ensures that the wireless device is kept connected to the network, without losing the...
was possible between the implementing countries.
At its height in 1986, the network had 158 base station
Base station
The term base station can be used in the context of land surveying and wireless communications.- Land surveying :In the context of external land surveying, a base station is a GPS receiver at an accurately-known fixed location which is used to derive correction information for nearby portable GPS...
s and about 27,000 subscribers in Germany and 1,770 in Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...
. At the end of 1988, there were 1,078 participants in West Berlin
West Berlin
West Berlin was a political exclave that existed between 1949 and 1990. It comprised the western regions of Berlin, which were bordered by East Berlin and parts of East Germany. West Berlin consisted of the American, British, and French occupation sectors, which had been established in 1945...
alone. The network was vastly oversubscribed
Erlang unit
The erlang is a dimensionless unit that is used in telephony as a statistical measure of offered load or carried load on service-providing elements such as telephone circuits or telephone switching equipment. It is named after the Danish telephone engineer A. K...
and finding an available channel could prove difficult.
The connection between base station and handset unencrypted
Encryption
In cryptography, encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information...
, so eavesdropping
Eavesdropping
Eavesdropping is the act of secretly listening to the private conversation of others without their consent, as defined by Black's Law Dictionary...
was easy and common. In rare cases, additional devices were added by both participants to encrypt conversations (such as discussions of important politicians).
The B-Netz would eventually be superseded by the technically superior C-Netz
C-Netz
The Radio Telephone Network C , was a first generation analog cellular phone system deployed and operated in Germany by DeTeMobil...
, which was put into operation on May 1, 1985.
Technical details
- MultiplexingMultiplexingThe multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred...
: Frequency division multiplexing- Bandwidth per channel: 14 kHz
- Channel spacingChannel spacingChannel spacing is a term used in radio frequency planning. It describes the frequency difference between adjacent allocations in a frequency plan. Channels for mediumwave radio stations, for example are allocated in internationally-agreed steps of 9 or 10 kHz: 10 kHz in ITU Region 2 and 9 kHz...
: 20 kHz
- DuplexingDuplex (telecommunications)A duplex communication system is a system composed of two connected parties or devices that can communicate with one another in both directions. The term multiplexing is used when describing communication between more than two parties or devices....
: Frequency division duplexing- Duplex distance: 4.6 MHz
- Transmitting power
- 20 wattWattThe watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s for stationary stations - 10 watts for mobile stations
- 20 watt
- Frequency ranges
Frequencies First set Second set Original B frequencies 148.41 MHz - 149.13 MHz 153.01 MHz - 153.73 MHz Augmented B2 frequencies 157,61 MHz - 158,33 MHz 162,21 MHz -162,93 MHz