Jaringan telepon umum: Béda antarrépisi
Konten dihapus Konten ditambahkan
m Ngarapihkeun éjahan, replaced: rea → réa (5), ngarupakeun → mangrupa (2), ea → éa (6), eo → éo |
m →Digital Channel: Ngarapihkeun éjahan, replaced: modern → modérn |
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Baris ka-27:
The basic digital circuit in the PSTN is a 64-[[Kbit/s|kilobits-per-second]] channel, originally designed by [[Bell Labs]], called Digital Signal 0 ([[DS0]]). To carry a typical phone call from a [[calling party]] to a [[called party]], the audio sound is digitized at an 8 kHz sample rate using 8-bit [[pulse code modulation]] (PCM). The call is then transmitted from one end to another via telephone exchanges. The call is [[circuit switching|switched]] using a [[Signaling (telecommunication)|signaling]] [[protocol (computing)|protocol]] ([[SS7]]) between the telephone exchanges under an overall [[routing in the PSTN|routing strategy]].
The DS0s are the basic granularity at which [[circuit switching|switching]] takes place in a [[telephone exchange]]. DS0s are also known as [[timeslot]]s because they are multiplexed together using [[time-division multiplexing]] (TDM). Multiple DS0s are multiplexed together on higher capacity circuits into a [[DS1]] signal, carrying 24 DS0s on a North American or Japanese [[T-carrier|T1]] line, or 32 DS0s (30 for calls plus two for framing and signalling) on an [[E-carrier|E1]] line used in most other countries. In
The timeslots are conveyed from the initial multiplexer to the exchange over a set of equipment collectively known as the [[access network]]. The access network and inter-exchange transport of the PSTN use [[synchronization|synchronous]] optical transmission ([[SONET]] and [[Synchronous digital hierarchy|SDH]]) technology, although some parts still use the older [[PDH]] technology.
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