Communications system
aspect of study in telecommunications
trunked radio system
telecommunications network
emergency communication system
design language
Law Enforcement Online
Imperial Wireless Chain
simplex communication
intercom
Tracking and Data Relay Satellite System
semaphore line
signal box
Automatic Transmitter Identification System
1MC
C2000
AN/ARC-34
C2k
paging service
duplex communication
transmission line
European Data Relay System
Universal Mobile Telecommunications System
General Packet Radio Service