Markdown

DVB

DVB is the Acronym for Digital Video Broadcasting

Broadcasters and network operators use this family of open standards to send television as digital data instead of an analog color picture. In much of Europe the analog system it replaced was Phase Alternating Line (PAL), and the same digital family is used in many other regions as well. The specifications are published so manufacturers can build interoperable receivers, and they cover satellite, cable, and terrestrial delivery.

A tuner, built into the television or placed in a separate receiver, locks onto one slice of spectrum or cable bandwidth. That slice carries a multiplex: several programs sharing the capacity, along with the listing data the receiver needs to name them.

Delivery Paths

Picture and sound can be prepared once and then adapted to the route. What changes is the modulation and the equipment at the household.

PathHow It ArrivesHousehold Equipment
SatelliteRelayed from a broadcast satellite to a dishA dish and a tuner for that satellite signal
CableSent through the operator’s cable plantA cable feed and a tuner for that plant
TerrestrialRadiated from broadcast towersAn antenna and a tuner for the local transmission

What the Signal Carries

  • Programs: Video and sound for more than one service share the multiplex, so a single satellite, cable, or terrestrial channel can hold a lineup rather than one analog station.
  • Listing data: Service names, schedules, and channel numbers travel with the programs so the receiver can build a guide.
  • Access control: A distributor can mark a pay service so only an authorized receiver presents it, while other services in the same multiplex remain open.

Later Editions

The first editions moved each route from analog color to a digital multiplex. Later editions keep satellite, cable, and terrestrial delivery and use the available bandwidth more carefully, so the same kind of path can hold more services or a finer picture. The household does not change routes to gain that. The tuner has to match the edition the broadcaster or operator is actually sending.