DTMF

Integrated Services Digital Network Consumer and industry perspectives 1 Normally, a PBX is connected via a T1 with robbed bit signaling to indicate on- hook or off-hook conditions and MF and DTMF tones to encode the destination number

Modulation - List of common digital modulation techniques 1 Dual-tone multi-frequency (DTMF)

History of mobile phones - Radio Common Carrier 1 Other systems used DTMF

History of mobile phones - Emergence of automated services 1 This was a push-button telephone, and used transistors and DTMF signaling to improve its operational reliability

Payment Card Industry Data Security Standard - PCI compliance in call centers 1 The DTMF tones are converted to monotones so the agent cannot recognize them and so that they cannot be recorded

Real-time Transport Protocol - Profiles and Payload formats 1 The profile defines the codecs used to encode the payload data and their mapping to payload format codes in the Payload Type (PT) field of the RTP header. Each profile is accompanied by several payload format specifications, each of which describes the transport of a particular encoded data. The audio payload formats include G.711, G.723, G.726, G.729, GSM, QCELP, MP3, and DTMF, and the video payload formats include H.261, H.263, H.264, and MPEG-4.

Telephone exchange - Historic perspective 1 Exchanges based on the Strowger switch were eventually challenged by other exchange types and later by crossbar technology. These exchange designs promised faster switching and would accept pulses faster than the Strowger's typical 10 pps—typically about 20 pps. At a later date many also accepted DTMF "touch tones" or other tone signaling systems.

Telephone exchange - Historic perspective 1 A transitional technology (from pulse to DTMF) had DTMF link finders which converted DTMF to pulse, to feed to older Strowger, panel, or crossbar switches. This technology was used as late as mid

Telephone exchange - Early automatic exchanges 1 The telephone exchange automatically senses an off-hook condition on the telephone when the user removes a handset from the switchhook and provides dial tone to that phone to indicate to the user that the exchange is ready to receive dialed digits. The pulses or DTMF tones generated by the telephone are processed and a connection is established to the called telephone within the same exchange or to another distant exchange.

Telephone exchange - Electromechanical signaling 1 In Bell System trunks, it was common to use 20 pulse-per-second between crossbar switches and crossbar tandems. This was twice the rate of Western Electric/Bell System telephone dials. Using the faster pulsing rate made trunk utilization more efficient because the switch spent half as long listening to digits. DTMF was not used for trunk signaling.

Telephone exchange - Electromechanical signaling 1 Multi-frequency (MF) was the last of the pre- digital methods. It used a different set of tones sent in pairs like DTMF. Dialing was preceded by a special keypulse (KP) signal and followed by a start (ST). Variations of the Bell System MF tone scheme became a CCITT standard. Similar schemes were used in the Americas and in some European countries including Spain. Digit strings between switches were often abbreviated to further improve utilization.

Telecom switch - Historic perspective 1 Exchanges based on the Strowger switch were eventually challenged by Panel switch|other exchange types and later by Crossbar switch|crossbar technology. These exchange designs promised faster switching and would accept pulses faster than the Strowger's typical 10 pps— typically about 20 pps. At a later date many also accepted DTMF touch tones or other tone signaling systems.

Telecom switch - Electromechanical signaling 1 Multi-frequency|Multi-frequency (MF) was the last of the pre-digital methods. It used a different set of tones sent in pairs like DTMF. Dialing was preceded by a special keypulse (KP) signal and followed by a start (ST). Variations of the Bell System MF tone scheme became a ITU-T|CCITT standard. Similar schemes were used in the Americas and in some European countries including Spain. Digit strings between switches were often abbreviated to further improve utilization.

Telephone - Details of operation 1 The keys control a tone generator circuit (not shown) that makes DTMF tones that the exchange receives

Interactive Voice Response 1 'Interactive voice response' ('IVR') is a technology that allows a computer to interact with humans through the use of voice and dual-tone multi-frequency signaling|DTMF tones input via keypad.

Interactive Voice Response - History 1 DTMF telephones enabled the use of in- band signaling, i.e., they transmit audible tones in the same 300Hz to 3.4kHz range occupied by the human voice

Interactive Voice Response - History 1 The mature technology allowed clusters of 96 channels of high-density digital phone interface gear (terminating four T1 lines of twenty four channels each) to each be controlled by one application processor, running individual applications, one per channel, accepting DTMF touch tone inputs, accessing a large stored vocabulary for output, recording and playing back user speech when necessary.

Interactive Voice Response - History 1 With improvements in technology, systems could use speaker-independent voice recognition of a limited vocabulary instead of requiring the person to use DTMF signaling.

Interactive Voice Response - Technologies used 1 DTMF decoding and speech recognition are used to interpret the caller's response to voice prompts. DTMF tones are entered via the telephone keypad.

Interactive Voice Response - Technologies used 1 In telecommunications, an 'audio response unit' (ARU) is a device that provides synthesized voice responses to DTMF keypresses by processing calls based on (a) the call-originator input, (b) information received from a database, and (c) information in the incoming call, such as the time of day.

Mobile radio telephone - Radio Common Carrier 1 Other systems used DTMF

Media server - Media Servers in Telephony 1 Conferencing servers may also need other specialized functions like loudest talker detection, or Transcode|transcoding of audio streams, and also interpreting DTMF tones used to navigate menus

Area code - History 1 Such numbering strategies became less important when the Bell System introduced Dual-tone multi-frequency (DTMF) signaling in its Touch-Tonereg; service starting in 1963, where all digits were generated in the same amount of time.

Origins 1 Additionally, telephone systems used pulse dialling instead of later DTMF tones; briefly activating the hook once has the same effect as dialling 1, so repeatedly pushing the hook might result in calling

Nokia Lumia Diagnostic Tool 1 On this diagnostic tool, a user can run tests on the following: Accelerometer, ALS, audio loopback, camera, battery status, DTMF, gyroscope, hardware buttons, headset detection, LCD white, lights, life timer, magnetometer, power source, proximity, speaker, touch and vibration. It's also possible to perform all the tests in one run.

ISDN - Consumer and industry perspectives 1 Normally, a PBX is connected via a T1 with robbed bit signaling to indicate on- hook or off-hook conditions and Multi- frequency|MF and Dual-tone multi- frequency|DTMF tones to encode the destination number

Improved Mobile Telephone Service - Terminal 1 These were essentially modified walkie- talkies with a DTMF (dual tone multi- frequency) keypad attached on the front panel, which fooled the terminal into believing an IMTS mobile was using the system

Intelligent network service - SS7 architecture 1 * 'Specialized Resource Function (SRF)' or 'Intelligent Peripheral (IP)' This is a node which can connect to both the SSP and the SCP and delivers additional special resources into the call, mostly related to voice data, for example play voice announcements or collect DTMF tones from the user.

Speex - Features 1 In practice, the best trade-off is between complexity 2 and 4,[ x- manual/node4.html#SECTION Codec Description] though higher settings are often useful when encoding non-speech sounds like DTMF tones, or if encoding is not in real-time.

Premium-rate telephone number 1 One variant, targeted at children too young to dial a number, enticed children to hold the phone up to the television set while the DTMF tones of the number were played

Nokia Lumia Diagnostic Tool 1 On this diagnostic tool a user can run tests on the following: Accelerometer, ALS, audio loopback, camera, battery status, DTMF, gyroscope, hardware buttons, headset detection, LCD white, lights, life timer, magnetometer, power source, proximity, speaker, touch and vibration. It's also possible to perform all the tests in one run.

WebRTC - Design 1 As of March 2012 the IETF WebRTC Codec and Media Processing Requirements draft requires implementations to provide PCMA/PCMU (RFC 3551), Telephone Event as DTMF (RFC 4733), and Opus (audio format)|Opus (RFC 6716), along with a number of video codec minimum capabilities. The Peerconnection, Data channels and a media capture browser APIs are detailed in the W3C.

G Dual-tone multi-frequency signaling (DTMF), fax transmissions, and high- quality audio cannot be transported reliably with this codec. DTMF requires the use of the RTP Payload for DTMF Digits, Telephony Tones, and Telephony Signals as specified in RFC

Nuance Communications - Nuance history prior to the 2005 merger with ScanSoft 1 designing and developing speech solutions requires a different skill-set and mind-set to that of traditional DTMF solutions.

Pager - History 1 The Bell System Bellboy radio pagers each used three tuned reed receiver relays, each relay tuned to one of 33 different frequencies, selectively ringing a particular customer when all three relays were activated at the same time -- a precursor of DTMF.

Modulator - List of common digital modulation techniques 1 **Dual-tone multi-frequency (DTMF)

PCI DSS - PCI compliance in call centers 1 The Dual-tone multi-frequency signaling|DTMF tones are converted to monotones so the agent cannot recognize them and so that they cannot be recorded

Phreaking - Switch hook and tone dialer 1 It is notable that the two methods can be combined: Even if the exchange does not support DTMF, the key lock can be circumvented by switch-hooking, and the tone dialer can be then used to operate automated DTMF controlled services that can't be used with rotary dial.

Jingle (protocol) - Clients supporting Jingle 1 * Yate (telephony engine)|Yate/YateClient supports Jingle in both client and server mode, audio and file transfer, also call transfer and DTMF.

Jitsi - Features 1 * Dual-tone multi-frequency signaling|DTMF support with SIP INFO, Real-time Transport Protocol|RTP (RFC 2833/RFC 4733), In-band

Voice browser 1 A voice browser presents information aurally, using pre-recorded audio file playback or text-to-speech synthesis software. A voice browser obtains information using speech recognition and keypad entry, such as DTMF detection.

Microsoft Speech Server 1 The 'Microsoft Speech Server' is a product from Microsoft designed to allow the authoring and deployment of Interactive voice response|IVR applications incorporating Speech Recognition, Speech Synthesis and Dual-tone multi- frequency|DTMF.

Dual-tone multi-frequency signaling 1 DTMF is standardized by ITU-T Recommendation [ Q.23]

Dual-tone multi-frequency signaling - Multifrequency signaling 1 Prior to the development of DTMF, numbers were dialed on automated telephone systems by means of pulse dialing (dial pulse, DP, in the United States|U.S.) or loop disconnect (LD) signaling, which functions by rapidly disconnecting and re-connecting the calling party's telephone line, similar to flicking a light switch on and off

Dual-tone multi-frequency signaling - Multifrequency signaling 1 Other vendors of compatible telephone equipment called the Touch-Tone feature Tone dialing or DTMF, or used their own registered trade names such as the Digitone of Northern Electric (now known as Nortel Networks).

Dual-tone multi-frequency signaling - Multifrequency signaling 1 The DTMF system uses eight different frequency signals transmitted in pairs to represent 16 different numbers, symbols and letters - as detailed below.

Dual-tone multi-frequency signaling - Multifrequency signaling 1 As a method of in-band signaling, DTMF tones were also used by cable television Broadcasting|broadcasters to indicate the start and stop times of local commercial insertion points during station breaks for the benefit of cable companies. Until better out-of-band signaling equipment was developed in the 1990s, fast, unacknowledged, and loud DTMF tone sequences could be heard during the commercial breaks of cable channels in the United States and elsewhere.

Dual-tone multi-frequency signaling - Multifrequency signaling 1 Based on this prior success with using MF by specialists to establish long-distance telephone calls, Dual-tone multi-frequency (DTMF) signaling was developed for the consumer to signal their own telephone- call's destination telephone number instead of talking to a telephone operator.

Dual-tone multi-frequency signaling - Multifrequency signaling 1 DTMF, as used in push-button telephone tone dialing, was known throughout the Bell System by the trademark Touch-Tone

Dual-tone multi-frequency signaling - Multifrequency signaling 1 Multi-frequency signaling is a precursor of modern DTMF signaling (TouchTone), now used for subscriber signalling. DTMF uses eight frequencies.

Dual-tone multi-frequency signaling - #, *, A, B, C, and D 1 DTMF tones are also used by some cable television networks and radio networks to signal the local cable company/network station to insert a local advertisement or station identification. These tones were often heard during a station ID preceding a local ad insert. Previously, terrestrial television stations also used DTMF tones to shut off and turn on remote transmitters.

Dual-tone multi-frequency signaling - #, *, A, B, C, and D 1 DTMF signaling tones can also be heard at the start or end of some VHS (Video Home System) cassette tapes. Information on the master version of the video tape is encoded in the DTMF tone. The encoded tone provides information to automatic duplication machines, such as format, duration and volume levels, in order to replicate the original video as closely as possible.

Dual-tone multi-frequency signaling - #, *, A, B, C, and D 1 DTMF tones are sometimes used in caller ID systems to transfer the caller ID information, but in the United States only Bell 202 modem|Bell 202 modulated Frequency-shift keying|FSK signaling is used to transfer the data.

Dual-tone multi-frequency signaling - Keypad 1 The DTMF keypad is laid out in a 4times;4 matrix in which each row represents a low frequency and each column represents a high frequency. Pressing a single key sends a sinusoidal tone for each of the two frequencies. For example, the key 1 produces a superimposition of tones of 697 and 1209 hertz (Hz). Initial pushbutton designs employed levers, so that each button activated two contacts. The tones are decoded by the switching center to determine the keys pressed by the user.

Dual-tone multi-frequency signaling - Special tone frequencies 1 As with other multi-frequency receivers, DTMF was originally decoded by tuned filter banks. Late in the 20th century most were replaced with digital signal processors. Although DTMF can be decoded using any frequency domain transform (such as the popular Fast Fourier transform), the Goertzel algorithm is a common algorithm to consider due to its high performance for DTMF.

Sign-on - Sign-on sequence 1 # A signal to turn on remote transmitters may be played—this is usually a series of DTMF|touch tones.

Softphone - Features 1 A typical softphone has all standard telephony features (DND, Mute, Dual-tone multi-frequency|DTMF, Flash, Hold, Transfer etc.) and often additional features typical for online messaging, such as user presence indication, video, wide-band audio. Softphones provide a variety of audio codecs, a typical minimum set is G.711 and G

Western Electric - Technological innovations 1 DTMF was generally referred to by the trademarked name, Touch-Tone.

Ekiga - Technical features 1 * Dual-tone multi- frequency|DTMF support (SIP and H.323)

Caller ID - Operation 1 Instead of sending the caller ID in between the first and second ring, some systems use a line reversal to announce the caller ID, or caller ID signals are simply sent without any announcement. Instead of Bell 202, the European alternative V.23 is sometimes used, (without the 75-baud reverse channel) or the data is sent using DTMF signalling.

Caller ID - Notes 1 Some providers use frequency-shift keying|FSK, others use the DTMF protocol.

✆ 1 Until approximately the 1970s most telephones used a rotary dial, which was superseded by the modern Dual-tone multi-frequency signaling|DTMF push- button dial, first introduced by ATT in 1963.Dodd, Annabel Z., The Essential Guide to Telecommunications

List of algorithms - Digital signal processing 1 * Goertzel algorithm: identify a particular frequency component in a signal. Can be used for DTMF digit decoding.

Push-button telephone 1 On 18 November 1963 the Bell System in the United States officially introduced dual- tone multi-frequency (DTMF) technology under its registered Touch-Tone® mark

Push-button telephone 1 Although DTMF was the driving technology implemented in push-button telephones, some telephone manufacturers used push- button keypads to generate pulse dial signaling. Before the introduction of Touch- Tone telephone sets, the Bell System sometimes used the term push-button telephone to refer to key system telephones, which were rotary dial telephones that also had a set of push-buttons to select one of multiple telephone circuits, or to activate other features.

Push-button telephone - Touch-Tone 1 The international standard for telephone signaling utilizes dual-tone multi-frequency (DTMF) signaling, more commonly known as Touch-Tone dialing

Push-button telephone - Touch-Tone 1 The Touch-Tone system uses audible tones for each of the digits zero through nine. Later this was expanded by two keys labeled with an asterisk (*) and the pound or hash sign (#) to represent the 11th and 12th DTMF signals. These signals accommodate various additional services and customer-controlled calling features.[ g/?id=3625 Great Achievements- Telephone Timeline]

Push-button telephone - Touch-Tone 1 The DTMF standard assigns specific frequencies to each column and row of push-buttons in the telephone keypad; the columns in the push-button pad have higher-frequency tones, and rows have lower-frequency tones in the audible range. When a button is pressed the dial generates a combination signal of the two frequencies for the selected row and column, a dual-tone signal, which is transmitted over the phone line to the telephone exchange.

Push-button telephone - Touch-Tone 1 When announced, the DTMF technology was not immediately available on all switching systems

Push-button telephone - Touch-Tone 1 While a tone-to-pulse converter could be deployed to any existing mechanical office line using 1970s technology, its speed would be limited to pulse dialling rates.[ TE/DTMF/MSAN-108.PDF Mitel Application note MSAN-108]: Applications of the MT8870 integrated DTMF receiver, Page A50, Figure 2 (MT8870 DTMF receiver, MT4325 Pulse dialler), June

Push-button telephone - DTMF keypad layout 1 This research resulted in the design of the DTMF keypad that arranged the push- buttons into 12 positions in a 3-by-4 position rectangular array, and placed the 1, 2, and 3 keys in the top row for most accurate dialing

Push-button telephone - DTMF keypad layout 1 The DTMF keyboard layout broke with the tradition established in cash registers (and later adopted in calculators and computers) of having the 0 key at the bottom and the remaining keys increasing in rows above.[ 2019/why-do-telephone-keypads-count-from-the- top-down-while-calculators-count-from-the-bottom- up Why do telephone keypads count from the top down, while calculators count from the bottom up?] This was due to research conducted by Bell Labs using test subjects unfamiliar with keypads

Push-button telephone - Pulse dialing 1 Historically, not all push-button telephones used DTMF dialing technology. Some manufacturers implemented pulse dialing with push-button keypads and even Western Electric produced several telephone models with a push-button keypad that could also emit traditional dial pulses. Sometimes the mode was user-selectable with a switch on the telephone. Pulse mode push-button keypads typically stored the dialed number sequence in a digit collector register to permit rapid dialing for the user.

Push-button telephone - Features 1 Most analog telephone adapters for Internet-based telecommunications (VoIP) recognise and translate DTMF tones but ignore dial pulses, an issue which also exists for some Private branch exchange|PBX systems. Like cellular handsets, telephones designed for voice- over-IP use out-of-band signalling to send the dialled number.

Automated attendant - Feature Description 1 Callers who have a touch tone (DTMF) phone can dial an extension number or, in most cases, wait for operator (attendant) assistance

Amateur radio repeater - Repeater networks 1 This feature is typically done with DTMF tones to control the network infrastructure

Professional Mobile Radio - Introduction 1 When private- or professional-mobile-radio (PMR) first started the systems simply consisted of a single base station with a number of mobiles that could communicate with this single base station. These systems are still in widespread use today with taxi firms and many others using them for communication. Now facilities such as DTMF and CTCSS provide additional calling selection.

Professional Mobile Radio - Selective calling 1 Many systems operate with the remote or mobile stations being able to hear all the calls being made. This may not always be satisfactory and a system of selective calling may be required. There are several ways of achieving this, including Dual Tone Multiple Frequency (DTMF) signalling and Continuous Tone Coded Squelch System (CTCSS).

Professional Mobile Radio - Selective calling 1 DTMF is a system that is widely used for telephone signalling and is almost universally used for touch tone dialing for landline telephones today. It uses set pairs of tones that are used to carry the information. The eight frequencies used are 697, 770, 852, 941 Hz which are termed the low tones and 1209, 1336, 1477, and 1633 Hz which are high tones. One high and one low tone is used together and the various combinations are used to represent different numbers and symbols.

Professional Mobile Radio - Selective calling 1 The disadvantage of this system is that if the receiver does not pick up the code at the instant the DTMF signalling takes place then it will not respond to any of the message

Professional Mobile Radio - Modulation 1 Base stations must be located sufficiently far apart so that interference is not experienced, and also selective calling techniques such as CTCSS and DTMF are used to ensure that as many mobiles as possible can use a given channel.

Signaling (telecommunications) - In-band and out-of-band signaling 1 In the public switched telephone network (PSTN), in-band signaling is the exchange of call control information within the same channel that the telephone call itself is using. An example is dual-tone multi- frequency signaling (DTMF), which is used on most telephone lines to customer premises.

Signaling (telecommunications) - Line versus register signaling 1 Finally, starting in the second half of the century, address signaling is by DTMF.

Signaling (telecommunications) - Classification 1 *E and M signaling (EM) is an out-of-band channel-associated signaling system. The base system is intended for line signaling, but if decadic pulses are used it can also convey register information. EM line signaling is however usually paired with DTMF register signaling.

In-band signaling 1 In telecommunications, 'in-band signaling' is the sending of metadata and control signal|control information within the same band or channel used for voice (e.g. DTMF tones) and can be heard by the callers, as opposed to out-of-band signals (e.g. Signalling System No. 7|SS7 control signals) which cannot be heard as they are on a different channel or band.

In-band signaling - Telephone 1 For example, when dialing from a land-line telephone, the telephone number is encoded and transmitted across the telephone line in form of dual-tone multi- frequency signaling (DTMF)

In-band signaling - Non-telephone 1 As a method of in-band signaling, DTMF tones were also used by cable television Broadcasting|broadcasters to indicate the start and stop times of local insertion points during station breaks for the benefit of cable companies. Until better, out-of- band signaling equipment was developed in the 1990s, fast, unacknowledged, and loud DTMF tone sequences could be heard during the commercial breaks of cable channels in the United States and elsewhere.

In-band signaling - Non-telephone 1 These DTMF sequences were sent by the originating cable network's equipment at the uplink satellite facility, and were decoded by equipment at local cable companies. A specific tone sequence indicated the exact time that the feeds should be switched to and away from the master control feed, to locally-broadcast commercials.

In-band signaling - Non-telephone 1 An example of a cable company DTMF sequence code would communicate the following to the cable company's broadcast equipment:

In-band signaling - Non-telephone 1 DTMF signaling in the cable industry went away because it was distracting to viewers, it was susceptible to interference when DTMF tones were sounded by characters in television shows (a character dialing a Touch-Tone telephone in a television show might convince the cable company computers to switch away from a hot feed to dead air), and the cost of human-imperceptible signaling technologies decreased.

Fantasy football (American) - History 1 Trading and other game interactions took place via DTMF (touchtone) phone technologies

Auto dialer - Modem versus telephony boards 1 Traditional advantages of using telephony cards over simple modems include detecting DTMF|touch tones and transferring calls directly through to the caller.

Audio Messaging Interchange Specification - Technical background 1 AMIS is completely in-band and analog, meaning that the control commands to indicate who the message is from, the time received and from mailbox or caller ID information is all sent as a series of DTMF (Touch tone) digits - along with the message itself, which is transmitted (played and re-recorded by the target system) in real time.

Multi-frequency shift keying - 2-tone MFSK 1 It is possible to combine two MFSK systems to increase the throughput of the link. Perhaps the most widely used 2-tone MFSK system is dual-tone multi-frequency (DTMF), better known by its ATT trademark of Touch Tone. Another is the Multi-frequency (MF) scheme used during the 20th century for in-band signalling on trunks between telephone exchanges. Both are examples of in-band signaling schemes, i.e., they share the user's communication channel.

Multi-frequency shift keying - 2-tone MFSK 1 Symbols in the DTMF and MF alphabets are sent as tone pairs; DTMF selects one tone from a high group and one from a low group, while MF selects its two tones from a common set. DTMF and MF use different tone frequencies largely to keep end users from interfering with inter-office signaling. In the 1970s, MF began to be replaced by digital out-of-band signaling, a conversion motivated in part by the widespread fraudulent use of MF signals by end users known as phone phreaks.

Multi-frequency shift keying - VHF UHF communications 1 DTMF was initially developed for telephone line signaling. It is frequently used for telecommand (remote control) applications over VHF and UHF voice channels.

Voiceportal 1 In telecommunications circles, Voice portals may be referred to as Interactive Voice Response (IVR) systems, but this term also includes DTMF services.

Telephone banking - Operation 1 To access telephone banking, the customer would call the special phone number set up by the financial institution. The service can be provided using an automated system, using speech recognition and Dual-tone multi-frequency signaling|DTMF technology or by live customer service representatives.

Line card 1 In some telephone exchange designs, the line cards generate ringing (telephony)|ringing current and decode DTMF signals

Broadcast automation - Early analog systems 1 Satellite programming often used audible dual-tone multi-frequency (DTMF) signals to trigger events at affiliate stations. This allowed the automatic local insertion of ads and station IDs. Because there are 12 (or 16) tone pairs, and typically four tones were sent in rapid succession (less than one second), more events could be triggered than by sub-audible tones (usually 25Hz and 35Hz).

Walkie-talkie - Contemporary use 1 Some units (especially amateur HTs) also include DTMF keypads for remote operation of various devices such as repeaters

Switching center - Early automatic exchanges 1 A telephone exchange automatically senses an off-hook condition of the telephone when the user removes the handset from the switchhook or cradle. The exchange provides dial tone at that time to indicate to the user that the exchange is ready to receive dialed digits. The pulses or DTMF tones generated by the telephone are processed and a connection is established to the destination telephone within the same exchange or to another distant exchange.

G Use 1 G is mostly used in Voice over IP (VoIP) applications due to its low bandwidth requirement. Music or tones such as DTMF or fax tones cannot be transported reliably with this codec, and thus some other method such as G.711 or out-of-band signaling|out-of-band methods should be used to transport these signals. The complexity of the algorithm is below 16 MIPS. 2.2 kilobytes of RAM is needed for codebooks.

Voice-based marketing automation - Functionality 1'Hosted IVR' (interactive voice response) is a Cloud computing|cloud- based technology that allows a computer to interact with humans through the use of voice and Dual-tone multi-frequency signaling|DTMF tones input via keypad

Centrex - Birth of Centrex 1 Among other changes, the Phase 3 consoles used DTMF rather than multifrequency pulsing

Telephone keypad 1 The contemporary keypad is laid out in a 4times;3 grid, although the original dual- tone multi-frequency|DTMF system in the new keypad had an additional column for four now-defunct menu selector keys

Telephone keypad - Letter mapping 1 On certain BlackBerry devices, a user can press the Alt key, followed by the desired letter, and the device will generate the appropriate DTMF tone.[ le.asp?article=articles%2F2005%2Ft0310 %2F35t10%2F35t10.asp Blackberry Tips], PC World, October

Loop around 1 *Using uncommon DTMF tones (A through D) in the telephone number

Sign-off - Sign-off sequence 1 # A signal to turn off remote transmitters may be played—this is usually a series of DTMF|touch tones. Once the transmission has been cut off there will usually only be Noise (video)|video static on television stations or Noise (radio)|radio static on radio stations.

D-STAR - Criticisms 1 With P25 designed for Govt and Federal Emergency use, it lacks Amateur-centric features for example, P25 amateur radio implementations do not use call sign routing, and they cannot control linked reflectors or repeaters but do have DTMF, telegrams, phone patch, MDC1200, TMS messaging, any many more signalling facilities, including several advanced security features.

Civil defense siren - Sirens in integrated public warning systems 1 Commonly used are DTMF broadcasts over phone lines (direct connection or standard PSTN) or over radio broadcast

Pulse dialing - Successor technologies 1 In 1963 the Bell System introduced dual- tone multi-frequency (DTMF) technology under the name Touch-Tone (a trademark in the U.S

Quik Call I 1 Selective calling is akin to the use of a lock on a door. A radio with carrier squelch is unlocked and will let any signal in. Selective calling locks out all signals except ones with the correct 'key', in this case a specific digital code. Selective calling systems can overlap; a radio may have (group call) and DTMF individual calling.

Savage Love - Other abbreviations 1 'DTMFA': Dump The Mother-Fucker Already (used at a closing of a response to indicate that immediately ending the writer's abusive or worthless relationship is advised).

Nokia Calls 1 The phone featured the ability to make conference calls, hold calls and send DTMF tones

History of The Weather Channel - The Live By It era: June 2001–August The Weather Star III was also discontinued from service as it did not meet DTMF tone and weather warning regulations

Hendrik van Rheede - Biography 1 They visited Simon van der Stel in Cape of Good Hope, and Groot Constantia; the area Drakenstein Local Municipality|Groot Drakenstein was named after him.[ articleid=61:a-different-history-of-franschoek-and-the-drakenstein- district-submitted-by-alan-montgomery-march-2010catid=6:latest- news A DIFFERENT HISTORY OF FRANSCHOEK and the DRAKENSTEIN DISTRICT] Van Rheede recommended measures for forestry and viniculture.[ UddDDtMF20Cpg=PA70lpg=PA70dq=Hendrik+van+Rheede+Drake nsteinsource=blots=DM4wpanlQnsig=wpdGJ69G4jwwad3_JXXrnKd MvIUhl=enei=CwgfTZqGBoWx8gO715yXBQsa=Xoi=book_resultct= resultresnum=6ved=0CDAQ6AEwBTgK#v=onepageqf=false New Scientist 25 Jun 1987] In 1687 Governor Van der Stel opened this region to farmers.[ ns_Cape_of_Good_Hope/introduction_english/39.htm Intro (English) to the Resolutions of Cape of Good Hope / Places named after members of the Council of Policy]

Blue box - Frequencies and timings 1 This set of MF tones was originally devised for Bell System switchboard operator|long- distance operators placing calls manually and predates the 1963 DTMF Touch-Tone system used by subscribers; in some 1950s and 1960s ATamp;T archive films, operators are shown asking callers for the number and pressing KP + area code + seven-digit number + ST manually to complete individual toll calls. The leading 1- trunk prefix was not dialled as the operator was already on a Long Lines trunk at this point.

Disney's Fantillusion 1 It features Float (parade)|floats and live performers covered in thousands of electronically controlled lights and a synchronized soundtrack controlled by a Dual-tone multi-frequency signaling (DTMF) tone broadcast along the parade route

Telephone interpreting - Access 1 * 'Automated': an Interactive voice response|Interactive Voice Response (IVR) application is employed to convert spoken or keyed Dual-tone multi- frequency|Dual Tone Multi Frequency (DTMF) data into a request for connecting to an interpreter in a specific language (identified by Language code|unique language-codes)

History of the Israeli–Palestinian conflict war: Yishuv Vs Palestinian Arabs and volunteers 1 [ FWXAOICpg=PA27lpg=PA27dq=un+partiti on+riots+molotov+cocktailssource=blots=q MlEAsb0mfsig=DVoapyubfD72AT- z3VspY_AgRaohl=ensa=Xei=3LDBUon_C Y_moASJqoHQBQved=0CCkQ6AEwADg U#v=onepageq=un%20partition%20riots% 20molotov%20cocktailsf=false The Arab- Israeli Conflict: The 1948 War.] Google Books'

Scansoft - Nuance history prior to the 2005 merger with ScanSoft 1 designing and developing speech solutions requires a different skill-set and mind-set to that of traditional DTMF solutions.

Novation CAT - The Apple-CAT II 1 Several specialized applications such as TSPS, The Cats Meow and Phantom Access were used to mimic standard telephone sounds such as standard numeric DTMF dial tones as well as blue box tones, ringing (both American and International), dial tones, call waiting alerts, busy signals, 2600Hz tones, and other effects such as payphone sounds

TuVox 1 'TuVox' is a company that produces VXML-based telephone speech- recognition applications to replace DTMF touch-tone systems for their clients.

FXO - Function 1 A similar FCO service provided no difference in local calling area (the distant exchange is in the same rate centre). Historically, it was a means to obtain features not available on the local exchange (such as DTMF tone dialling when first introduced in 1963) or keep an existing business telephone number operational after a cross-town move.

Tip and ring - Polarity 1 When Touch-Tone service was introduced in the 1960s, the dual-tone multi-frequency signaling (DTMF) tone generator also required correct polarity as it depended on the line power for operation

Model 500 telephone - Development 1 The model 1500 only had push buttons for the 10 digits, while the model 2500 used 12 keys and included the '*' and '#' DTMF signals to allow for extra signaling needed in advanced service features, such as voice response systems and call management.

Lineman's handset - Components 1 Originally, lineman's handsets featured a rotary dial, but modern sets use some variant of the standard 12-button Dual- tone multi-frequency|DTMF Telephone keypad|keypad

Lineman's handset - Components 1 * DTMF|Tone/pulse dialing selection switch

Telecommunications device for the deaf - Other legacy protocols 1 Other protocols used for text telephony are European Deaf Telephone (EDT) and Dual-tone multi-frequency signaling (DTMF).

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