B-Netz

B-Netzwas ananalog,commercialmobile radio telephonenetwork that was operated by theDeutsche BundespostinGermany(at first onlyWest Germany) from 1972 until 1994. The system was also implemented in neighboring countriesAustria,The NetherlandsandLuxembourg.TheBrefers to the fact that it was the country's second public mobile telephone network, following theA-Netz.

As opposed to its predecessor, it featured direct-dialing (so that human operators were not required to connect calls). Thefrequency planoriginally included only 38channels(with one call possible perfrequencychannel), 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 theB2-Netz.

A major limitation of system was that, in order to reach a subscriber, one had to know his location since thehandsetwould assume the localarea codeof the base station serving it.Handoffwas not possible and calls weredroppedwhen cells were switched.Roamingwas possible between the implementing countries.

At its height in 1986, the network had 158base stationsand about 27,000 subscribers in Germany and 1,770 inAustria.At the end of 1988, there were 1,078 participants inWest Berlinalone. The network was vastlyoversubscribedand finding an available channel could prove difficult.

The connection between base station and handset wasunencrypted,soeavesdroppingwas easy and common. In rare cases, additional devices were added by both participants to encrypt conversations (such as discussions of important politicians).

TheB-Netzwould eventually be superseded by the technically superiorC-Netz,which was put into operation on May 1, 1985.

Technical details

• Multiple xing:Frequency division multiple xing
  • Bandwidthper channel: 14kHz
  • Channel spacing:20 kHz
• Duple xing:Frequency-division duple xing ing
  • Duplex distance: 4.6 MHz
• Transmitting power
  • 20wattsfor stationary stations
  • 10 watts for mobile stations
• Frequency ranges

Frequencies	First set	Second set
OriginalBfrequencies	148.41–149.13 MHz	153.01–153.73 MHz
AugmentedB2frequencies	157.61–158.33 MHz	162.21–162.93 MHz

See also

• C-Netz