ICS Field
33.040.01 Telecommunication systems in general
33.040.20 Transmission systems
Including synchronization, cable systems, integrated cabling, pathways and multiplexing
33.040.30 Switching and signalling systems
Including telecommunication call charging and billing aspects
33.040.35 Telephone networks
Including Public Switched Telephone Networks (PSTN), Private Telecommunication Networks (PTN) and Private Integrated Service Networks (PISN)
33.040.40 Data communication networks
Including Packet Switched Public Data Networks (PSPDN) and Ethernet
ISDN, see 33.080
OSI local, wide and metropolitan area networks, see 35.110
Modems, see 35.180
33.040.50 Lines, connections and circuits
Including access networks and network elements
33.040.60 Powerline telecommunications
Power transmission and distribution, see 29.240.01
33.040.99 Other equipment for telecommunication systems