Phone Call Recorder

carrier wave

A carrier wave, or carrier is a waveform (usually sinusoidal) that is modulated (modified) to represent the information to be transmitted. This carrier wave is usually of much higher frequency than the modulating signal (the signal which contains the information). Carrier waves are used when transmitting radio signals to a radio receiver. Frequency modulation (FM) and amplitude modulation (AM) signals are both transmitted with the help of carrier waves. In the case of single-sideband modulation (SSB) the carrier is suppressed (and in some forms of SSB eliminated). The carrier must be reintroduced at the receiver by a beat frequency oscillator (BFO). The frequency for given radio station is actually the carrier wave's center frequency. Newer forms of radio communication, such as spread spectrum and ultra wide band, do not transmit a conventional carrier wave, nor does the European standard for HDTV, known as COFDM. COFDM should be thought of as an array of symmetrical carrier waves. The rules governing carrier wave propagation affect COFDM differently than 8VSB. Some forms of spread spectrum transmission and most forms of ultra wide band transmission are mathmatically defined as being devoid of carrier waves. The U.S. HDTV broadcast standard, 8VSB, does include a carrier, but at much lower relative power levels than the older NTSC standard.

List of telephony terms:

3gpp - a-law - abbreviated dialing - adsl - ani - answering machine - apn - automatic ring back - b-channel - baud - bell 202 modem - bit rate - bonding - bri - busy signal - cable modem - call-progress tones - call accounting - call capture - call forwarding - call originator - call park - call pick-up - call transfer - call waiting - call waiting deluxe - called party - caller id - caller id spoofing - calling party - carrier wave - cbr - ccitt - cdma - cdma2000 - cellular repeater - celp - channel - clec - clock rate - codec - collect call - conference - conference call - crc - csd - d-channel - data compression - device driver - dial-up - dial - dial tone - direct-inward-dialing - direct distance dialing - distinctive ring - dnis - dsl - dsp - dtmf - dtr - duplex - echo cancellation - edge - extension - fax - fcc - fdma - fidonet - follow-me - g.711 - g.723.1 - g.723 - g.726 - g.lite - gprs - gps - gsm - h.323 - harmonic - headphones - hscsd - hspda - iad - idsn - internet call waiting - isp - ivr - jack plug - local loop - long distance - microcontroller - mobile phone - modem - modulation - mu-law - music-on-hold - night service - off-hook - on-hook - pabx - pager - payphone - pbx - pcm - pots - prank call - precise tone plan - pstn - pulse dialling - push to talk - ring modulation - ring tone - ringback - ringing signal - rj11 - roaming - serial communications - serial port - signal noise - sim - simplex - sit - sms - softmodem - switchboard operator - tapi - tdma - telecommunications - telemarketing - telephone - telephone call - telephone card - telephone company - telephone exchange - telephone line - telephone number - telephone numbering plan - telephone operator - telephone switchboard - telephony - tts - twisted pair - umts - v.32 - v.32bis - v.34 - v.42bis - vbr - vertical service code - voicemail - voip - vox - wap - wav - wi-fi - wimax - wire