ELF (Extremely Low Frequency)

ELF radio has a frequency of 30–300 Hz and a wavelength of

10,000–1,000 km. ELF radio has application in submarine radio communications. See also electromagnetic spectrum, frequency, Hz, and wavelength.

• selector
• selenium
• self-healing
• self-learning bridge
• semiconductor
• send and pray
• sender
• Sequenced Packet Exchange (SPX)
• serial communications
• serial communications
• serial-in, parallel-out (SIPO)
• Serial Line Internet Protocol (SLIP)
• serial line protocol
• Serial Storage Architecture (SSA)
• server
• service
• service access point identifier (SAPI)
• service creation element (SCE)
• Service Level Agreement (SLA)
• service management system (SMS)
• service mark (SM)
• service node
• service-oriented architecture (SOA)
• service profile identification (SPID)
• service set identifier (SSID)