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Revision as of 19:51, 2 August 2024 edit Pol098 (talk \| contribs) Extended confirmed users, Pending changes reviewers 118,732 edits →See also: * Special information tone, e.g. "all network circuits busy" ← Previous edit		Latest revision as of 22:58, 13 September 2024 edit undo Kvng (talk \| contribs) Extended confirmed users, New page reviewers 108,221 edits m avoid unnec redirect. tag engvar.
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Line 1: {{Short description\|Type of call-progress tone}} {{other uses}} {{Use American English\|date=September 2024}} {{listen \|filename=NorthAmericanBusySignal.ogg Line 17 ⟶ 19: \|title5=Example of a United Kingdom busy signal \|description5=Listen to a busy signal from the United Kingdom.}} A '''busy signal''' (or '''busy tone''' or '''engaged tone''') in [[telephony]] is an audible [[call-progress tone]] or audible [[~~Signalling~~Signaling (~~telecommunication~~telecommunications)\|signal]] to the [[calling party]] that indicates failure to complete the requested [[Telecommunication circuit\|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]]. Line 41 ⟶ 44: Countries have different signaling tones that act as busy signals, in most cases consisting of a tone with equal on/off periods at a rate of between 60 and 120 interruptions per minute (i.p.m.). In [[North America]], the [[Precise Tone Plan]] used today employs two tones of 480 and 620 [[Hertz\|Hz]] at an amplitude of -24 dBm with a 0.5 [[second\|s]] on/off cadence. Prior to the adoption of the PreciseTone system, the busy signal generally had the same frequency as the [[dial tone]]. Until frequencies began to be standardized in the 1960s, telephone signals varied from telephone exchange to exchange. The [[ETSI\|European Telecommunications Standards Institute]] (ETSI) recommendation<!-- meaning 'ETSI guide', as opposed to an ETSI standard --> for busy tone is a 425 Hz tone at -20[[dBm]] in a 0.5 s on/off cadence. This sequence was already in use in Portugal, Spain, The Netherlands, (West-)Germany, Italy, Greece, Switzerland, Lichtenstein, Iceland, Norway, Andorra, Monaco, San Marino, and Vatican City prior to publication of the ETSI recommendation. ~~{{br}}The ETSI recommendation is now followed by all countries of the European Union. Historical oddities within the EU are:~~ * [[Republic of Ireland\|Ireland]] follows theThe ETSI recommendation ~~for~~is ~~the~~now ~~busy~~followed ~~tone,~~by ~~but~~all ~~the~~countries ~~ringback tone is~~of the ~~same~~European asUnion. ~~that~~Historical ~~used~~oddities inwithin the ~~[[United~~EU ~~Kingdom\|UK]].~~are: * [[Republic of Ireland\|Ireland]] follows the ETSI recommendation for the busy tone, but the ringback tone is the same as that used in the UK. * A few networks in France continue to use a 440 Hz/0.5 s sequence in place of the ETSI recommended 425 Hz/0.5 s sequence, but this is gradually being replaced. The ETSI recommendation is also the default (i.e. non-localized) busy tone generated by mobile phones that follow the [[3GPP\|GSM & 3GPP family of standards]]. {{br}}The ETSI recommendation is also followed by some [[ISDN]] equipment and [[Business telephone system\|PBX/office systems]] found outside Europe.▼ {{br}}Most countries of the former Soviet Union, including Russia, are not members of the ETSI. These former Soviet republics employ a 425 Hz busy tone with a 0.4 s on/off cadence.▼ ▲~~{{br}}~~The ETSI recommendation is also followed by some [[ISDN]] equipment and [[Business telephone system\|PBX/office systems]] found outside Europe. In the [[United Kingdom]], the busy tone is a single 400 Hz tone with equal 0.4 s (technically: 0.375 s) on/off periods. This was the case even when the UK was still part of the EU. The current 400 Hz/375ms tone was adopted in the mid to late 1960s and replaced the older busy tone, which was the same 400 Hz signal but at half the interruption rate (i.e. 0.75 s on, 0.75 s off).▼ ▲~~{{br}}~~Most countries of the former Soviet Union, including Russia, are not members of the ETSI. These former Soviet republics employ a 425 Hz busy tone with a 0.4 s on/off cadence. ▲In the [[United Kingdom]], the busy tone is a single 400 Hz tone with equal ~~0.4 s (technically:~~ 0.375 s) on/off periods. This was the case even when the UK was still part of the EU. The current 400 Hz/375ms tone was adopted in the mid -to -late 1960s and replaced the older busy tone, which was the same 400 Hz signal but at half the ~~interruption~~pulse ~~rate (i.e.~~duration, 0.75 s on, 0.75 s off). == See also ==