HUT Comms Lab., Timo O. Korhonen
Some features of PSTN of ´60 (cont.)
nNetwork
intelligence and value-added services
nnot
supported as such
noperators
were anyhow intelligent :)
nvalue
added services by tracking what happens in the area!
nInter-exchange
signaling
ncall setup
took about 15 seconds
nchannel-associated
signaling (CAS: No.5, R1,R2*)
nabout 10% of
trunk line capacity was taken by signaling
nOperation
and maintenance
nusing local
info-bases and local workforce
nnetwork
maintenance was based on on-field check-ups
*nowadays in ISDN & PLMN: common channel signaling
(CCS): SS7