Phone Call Recorder

frequency division multiple access

FDMA is an access technology and stands for Frequency Division Multiple Access. FDMA is used by radio systems to share the radio spectrum. The terminology "multiple access" implies the sharing of the resource amongst users and the "frequency division" describes how the sharing is done - by allocating users with different carrier frequencies of the radio spectrum. In FDMA given RF bandwidth is divided into smaller frequency bands called subdivisions. Each subdivision has its own IF carrier frequency. A control mechanism is used to ensure that two or more earth stations do not transmit in the same subdivision at the same time. Essentially, the control mechanism designates a receive station for each of the subdivision. In demand assignment systems, the control mechanism is also used to establish or terminate the voice-band links between the source and destination stations. Consequently, any of the subdivisions is used by any of the participating earth stations at any given time. If each subdivision carries only one 4-KHz voice-band channel, this is known as a single-channel per carrier (SCPC) system. When several voice-band channels are frequency-division multiplexed together to form a composite baseband signal comprised of groups, supergroups, or even mastergroups, a wider subdivision is assigned. This is referred to as multiple-channel per carrier (MCPC). FDMA also supports demand assignment besides fixed assignment. Demand assignment allows all users continuous an equal access of the entire transponder bandwidth by assigning carrier frequencies on a temporary basis using a statistical assignment process. The first FDMA demand-assignment system for satellite was developed by Comsat for use on the Intelsat series IVA and V satellites. In contrast to this methodology with Time Division Multiple Access TDMA, where users are separated in time, Code Division Multiple Access CDMA where users are separated by codes and other multiple access schemes: SDMA - Space division multiple access, CSMA - Carrier sense multiple access, and MF-TDMA - Multi-Frequency TDMA

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