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Publication of JPS5034404ApublicationCriticalpatent/JPS5034404A/ja
H04M9/00—Arrangements for interconnection not involving centralised switching
H04M9/001—Two-way communication systems between a limited number of parties
G—PHYSICS
G08—SIGNALLING
G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
G08B25/00—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
G08B25/01—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium
G08B25/016—Personal emergency signalling and security systems
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Engineering & Computer Science
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Signal Processing
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Computer Security & Cryptography
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Business, Economics & Management
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Emergency Management
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Physics & Mathematics
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General Physics & Mathematics
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Interconnected Communication Systems, Intercoms, And Interphones
(AREA)