C-Netz
The Radio Telephone Network C (German: Funktelefonnetz-C), abbreviated as C-Net (German: C-Netz), was a first generation analog cellular phone system deployed by Germany's DeTeMobil (formerly Deutsche Bundespost Telekom, currently T-Mobile) utilizing the C450 cellular standard. [1] It was the third and last update of a series of analog mobile phone systems used primarily within Germany, superseding the former B-Net analog mobile standard. It has been decommissioned, replaced by both the newer D-Net (GSM-900) and E-Net (GSM-1800) systems.
Timeline
The C-Net was officially introduced in 1985 (with unofficial trials in 1984) to replace the existing B-Net and B2-Net systems used in Germany at the time. Due to the cumbersome operation of existing B-Net mobile networks, early adoption of C-Net was very high, especially in rural areas which had lacked prior B-Net coverage.
By December of 1988, the service had grown to nearly 100,000 customers. It remained popular throughout the 1990s as a preferred system for mobile car phones. However, the system was loosing customers quickly by 1999, dropping from 230,000 customers in October to 210,000 customers in November. [2]
Eventually, Germany's C-Net service was shut down on December 31, 2000. Some cells near the German-Dutch border remained active for several more months but were eventually discontinued as well.
Technical Information
The C450 standard was developed by Siemens in 1980. [1] It is a 1G analog cellular standard that utilized non-audible in-band signaling, audio scrambling via band-inversion and cell network call queuing when congested. Cellular nodes varied in size, supporting a primary cell size of 15-20 km and micro-cells of 2-3 km in size. Channel bandwidth was typically 20 kHz, although it could be operated in a narrow-band mode of only 12 kHz. As its name implies, it was designed for the 450 MHz UHF frequency range.
Roaming
The C-Net's C450 standard was a heterogeneous cellular system that inhibited International roaming. France used the RadioCom 2000 analog standard while Denmark, the Netherlands and Switzerland used the NMT-450 analog standard.
Austria's own C-Net system utilized the NMT standard, not C450. [1] This differs from previous systems used in Austria (A-Net, B-Net) that were based on German standards.
Future Use
The C-Net radio spectrum in Germany has been reallocated for use with Flarion's Flash-OFDM mobile networking standard. It will primarily be used to service Germany's rail service with Internet connectivity under the name Railnet.