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Tone Signaling
A signal tone or signalling tone is a steady or pulsating periodic signal typically in the frequency range of sound for indicating a condition, communication protocol state, or serve as an audible warning. It may be composed of multiple frequency components, or could be a pure tone. In telephone systems, signaling tones are used as call progress tones for in-band indications to subscribers or operators. Certain telephone switching systems used tones, in-band or out-of-band, for signaling on trunks. Typical well-known call progress tones are dial tone, ringing tone, busy tone, and the reorder tone. A loud stutter tone is used to alert subscribers of a handset left off-hook, effectively disabling the circuit for receiving calls. Telephone service subscribers may subscribe to services, such as call forwarding, which may indicate function by a stutter dial tone. See also * Musical tone * Dual-tone multi-frequency signaling (DTMF) * Signaling (telecommunications) In telecommunica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periodic Function
A periodic function, also called a periodic waveform (or simply periodic wave), is a function that repeats its values at regular intervals or periods. The repeatable part of the function or waveform is called a ''cycle''. For example, the trigonometric functions, which repeat at intervals of 2\pi radians, are periodic functions. Periodic functions are used throughout science to describe oscillations, waves, and other phenomena that exhibit periodicity. Any function that is not periodic is called ''aperiodic''. Definition A function is said to be periodic if, for some nonzero constant , it is the case that :f(x+P) = f(x) for all values of in the domain. A nonzero constant for which this is the case is called a period of the function. If there exists a least positive constant with this property, it is called the fundamental period (also primitive period, basic period, or prime period.) Often, "the" period of a function is used to mean its fundamental period. A funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound
In physics, sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the brain. Only acoustic waves that have frequency, frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of to . Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges, allowing some to even hear ultrasounds. Definition Sound is defined as "(a) Oscillation in pressure, stress, particle displacement, particle velocity, etc., propagated in a medium with internal forces (e.g., elastic or viscous), or the superposition of such propagated oscillation. (b) Auditory sen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communication Protocol
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics (computer science), semantics, and synchronization of communication and possible Error detection and correction, error recovery methods. Protocols may be implemented by Computer hardware, hardware, software, or a combination of both. Communicating systems use well-defined formats for exchanging various messages. Each message has an exact meaning intended to elicit a response from a range of possible responses predetermined for that particular situation. The specified behavior is typically independent of how it is to be Implementation, implemented. Communication protocols have to be agreed upon by the parties involved. To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pure Tone
In psychoacoustics, a pure tone is a sound with a sinusoidal waveform; that is, a sine wave of constant frequency, phase-shift, and amplitude. By extension, in signal processing a single-frequency tone or pure tone is a purely sinusoidal signal (e.g., a voltage). A pure tone has the property – unique among real-valued wave shapes – that its wave shape is unchanged by linear time-invariant systems; that is, only the phase and amplitude change between such a system's pure-tone input and its output. Sine and cosine waves can be used as basic building blocks of more complex waves. As additional sine waves having different frequencies are combined, the waveform transforms from a sinusoidal shape into a more complex shape. When considered as part of a whole spectrum, a pure tone may also be called a ''spectral component''. In clinical audiology, pure tones are used for pure-tone audiometry to characterize hearing thresholds at different frequencies. Sound localization is often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Call Progress Tone
In telephony, call progress tones are audible tones that provide an indication of the status of a telephone call to the user. The tones are generated by a central office or a private branch exchange (PBX) to the calling party. Telecommunication equipment such as fax machines and modems are designed to recognize certain tones, such as dial tone and busy tone. The ITU-T E.180 and E.182 recommendations define the technical characteristics and intended usage of some of these tones. ToneScript is a tone description format that may be used to specify the tone. Many European systems follow the recommendations of the European Telecommunications Standards Institute (ETSI). Types * Busy tone (or busy signal) * Comfort tone *Conference call tone *Confirmation tone *Congestion tone *Dial tone * Disconnect tone *End of three-party service tone ( three-way calling) *Executive override tone * Holding tone *Preemption tone *Queue tone *Recall dial tone *Record tone * Recorder warning tone *R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In-band
In telecommunications, in-band signaling is the sending of control information within the same band or channel used for data such as voice or video. This is in contrast to out-of-band signaling which is sent over a different channel, or even over a separate network. In-band signals may often be heard by telephony participants, while out-of-band signals are inaccessible to the user. The term is also used more generally, for example of computer data files that include both literal data, and metadata and/or instructions for how to process the literal data. Telephony 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). The tones control the telephone system by instructing the telephone switch where to route the call. These control tones are sent over the same channel, the copper wire, and in the frequency range (300 Hz to 3.4 kHz) as the audio of the tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signaling (telecommunications)
In telecommunications, signaling is the use of signals for controlling communications. This may constitute an information exchange concerning the establishment and control of a telecommunication circuit and the management of the network. Classification Signaling systems may be classified based on several principal characteristics. In-band and out-of-band signaling In the public switched telephone network (PSTN), in-band signaling is the exchange of call control information within the same physical channel, or within the same frequency band, that the message (the callers' voice) is using. An example is dual-tone multi-frequency signaling (DTMF), which is used on most telephone lines to customer premises. Out-of-band signaling is telecommunication signaling on a dedicated channel separate from that used for the message. Out-of-band signaling has been used since Signaling System No. 6 (SS6) was introduced in the 1970s, and also in Signalling System No. 7 (SS7) in 1980 whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dial Tone
A dial tone (dialling tone in the UK) is a telephony signal sent by a telephone exchange or private branch exchange (PBX) to a terminating device, such as a telephone, when an off-hook condition is detected. It indicates that the exchange is working and is ready to initiate a telephone call. The tone stops when the first dialed digit is recognized. If no digits are forthcoming, the partial dial procedure is invoked, often eliciting a special information tone and an intercept message, followed by the off-hook tone, requiring the caller to hang up and redial. History Early telephone exchanges signaled the switchboard operator when a subscriber picked up the telephone handset to make a call. The operator answered requesting the destination of the call. When manual exchanges were replaced with automated switching systems, the exchange generated a tone to the caller when the telephone set was picked up, indicating that the system was ready to accept dialed digits. Each digit w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ringing Tone
Ringing tone (audible ringing, also ringback tone) is a signaling tone in telecommunication that is heard by the originator of a telephone call while the destination terminal is alerting the receiving party. The tone is typically a repeated cadence similar to a traditional power ringing signal (''ringtone''), but is usually not played synchronously. Various telecommunication groups, such as the Bell System and the General Post Office (GPO) developed standards, in part taken over by the European Telecommunications Standards Institute (ETSI) and other standards bodies. With modern cell phone and smartphone technology ringing tone can be customized and even used for advertising. Purpose and description When a telephone user initiates a telephone call, typically by dialing or selecting a telephone number on a telephone, the progress or status of the call attempt is indicated to the user audibly by several types of call progress tones. For example, during the period of routing the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Busy Tone
A busy signal (or busy tone or engaged tone) in telephony is an audible call-progress tone or audible signal to the calling party that indicates failure to complete the requested connection of that particular telephone call. The busy signal has become less common in the past few decades due to the prevalence of call waiting and voicemail. Reasons for a busy signal An otherwise unspecified busy signal indicates that the called number is occupied: * The called number is talking with another caller on the phone * The number is calling out * Someone else has called the number or is calling the number at the same time * The other line was left off-hook * It is otherwise unavailable The standard busy signal sometimes occurs (sometimes with an intercept message played over the busy) at the end of a call to indicate the other party has hung up (see Disconnect tone), but mostly the off-hook tone is used. In some phone companies in the United Kingdom, the busy signal is played after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reorder Tone
The reorder tone, also known as the fast busy tone, or the congestion tone, or all trunks busy (ATB) tone is an audible call progress tone in the public switched telephone network (PSTN) that is returned to a calling party to indicate that the call cannot be processed through the network. The tone characteristics vary by country or telephone administrations. In North America it is a dual-frequency tone of 620 Hz and 480 Hz interrupted 120 times per minute at a cadence of 0.25 seconds on, 0.25 off, i.e., two beeps per second. In EU countries and those following ETSI (European Telecommunication Standards Institute) recommendations, the cadence is the same as North America, i.e. 0.25 seconds on / 0.25 seconds off, but with a 425 Hz tone. The UK reorder tone uses a 400 Hz tone with a cadence of 0.4 seconds on, 0.35 seconds off, 0.225 seconds on, 0.525 seconds off. In some instances the Number Unobtainable Tone may be used instead. This is a continuous, uninterrup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musical Tone
Traditionally in Western classical music, Western music, a musical tone is a steady periodic function, periodic sound. A musical tone is characterized by its duration (music), duration, pitch (music), pitch, amplitude, intensity (or loudness), and timbre (or quality). The Musical note, notes used in music can be more complex than musical tones, as they may include aperiodic aspects, such as attack transient (acoustics), transients, vibrato, and envelope modulation. A ''simple tone'', or ''pure tone'', has a Sine wave, sinusoidal waveform. A ''complex tone'' is a combination of two or more pure tones that have a periodic pattern of repetition, unless specified otherwise. The Fourier theorem states that any periodic waveform can be approximated as closely as desired as the sum of a series of sine waves with frequencies in a harmonic series (mathematics), harmonic series and at specific phase (waves), phase relationships to each other. The common denominator frequency, which is al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
