HUT Comms.
Lab, Timo O. Korhonen
30
Public
switched telephone network (PSTN)
nThe oldest (1876) bearer network (other: ISDN, ATM, frame
relay, The Internet)
nAfter 1960 has got many renovations: data, fax, processor exchanges,
PCM, satellite communications, network intelligence
nPrimary characteristics
nAnalog access 300-3400 Hz
nCircuit switched connection
nSwitched bandwidth 64 kbit/s (Digital exchanges)
nImmobility (or very limited mobility)
nIntegrated nowadays especially with N-ISDN