- 産業: Telecommunications
- Number of terms: 29235
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ATIS is the leading technical planning and standards development organization committed to the rapid development of global, market-driven standards for the information, entertainment and communications industry.
A pseudobinary-coded signal in which a "0" ("zero") bit is represented by a zero-level electric current or voltage; a "1" ("one") bit is represented by a positive-level current or voltage if the quantity of "0" bits since the last "1" bit is even, and by a negative-level current or voltage if the quantity of "0" bits since the last "1" bit is odd. Note 1: Duobinary signals require less bandwidth than NRZ. Note 2: Duobinary signaling also permits the detection of some errors without the addition of error-checking bits.
Industry:Telecommunications
A pseudoternary signal, representing binary digits, in which (a) successive "marks" are of alternately positive and negative polarity and the absolute values of their amplitudes are normally equal and (b) "spaces" are of zero amplitude. Synonym bipolar signal.
Industry:Telecommunications
A public all-digital cellular network using TDMA techniques for multiplexing and using a transmission band around 900 MHz. GSM formerly identified the Groupe Speciale Mobile of the European Telecommunication Standards Institute (ETSI); today it is a worldwide standard. A GSM network can provide, besides telephony services, short messaging services (SMS) and data communication, in circuit- and/or packet mode. GSM signaling uses specific channels and protocols; voice is compressed at about 13 kb/s and error correcting algorithms (FEC) are used. The core network is based on a 64 kb/s circuit-switching technology. A more recent version uses an 1800 MHz band; modern terminals currently used in Europe can access both networks depending on traffic conditions and other parameters. A GSM version using a 1900 MHz access network is available in the United States.
Industry:Telecommunications
A public radio service rendered by fixed stations on frequencies below 1000 MHz used to provide (1) Basic Exchange Telecommunications Radio Service, which is public message communication service between a central office and subscribers located in rural areas, (2) public message communication service between landline central offices and different exchange areas which it is impracticable to interconnect by any other means, or (3) private line telephone, telegraph, or facsimile service between two or more points to which it is impracticable to extend service via landline.
Industry:Telecommunications
A public, all-digital cellular network that is standardized worldwide and that uses (a) TDMA techniques for multiplexing at approximately 900 MHz, (b) compressed voice at about 13 kb/s, (c) 16 kb/s circuit-switching technology, and (d) error-correcting algorithms.
Industry:Telecommunications
A publicly available implementation of a public-key encryption system using no trusted third party. Note: PGP can be used to apply a digital signature to a message without actually encrypting the text of the message. This is normally used in public postings where the user wants all readers to be able to see the message text and also wants the reader to be able to confirm that the message is unaltered from its original form. Once a digital signature is created with PGP, it is impossible for anyone to modify either the message or the signature without the modification being detected by PGP.
Industry:Telecommunications
A pulse free from the effects of the other pulses in the same signal. (A suitable testing signal is a repetitive pattern of one "one" and seven "zeros". )
Industry:Telecommunications
A pulse that has a waveform described by the gaussian distribution. Note: In the time domain, the amplitude of the waveform is given by where A is the maximum amplitude, and is the pulse half-duration at the 1/e points.
Industry:Telecommunications
A pulse used to achieve or maintain synchronism. Note: The term "synchronization pulse" is usually applied to analog signals, whereas the term "synchronization bit" is usually applied to digital data streams. Synonym sync pulse.
Industry:Telecommunications
A pulse used to achieve or maintain synchronism. Note: The term "synchronization pulse" is usually applied to analog signals, whereas the term "synchronization bit" is usually applied to digital data streams. Synonym sync pulse.
Industry:Telecommunications
