Dro

Dielectric Resonator or Dielectrically Stabilized Oscillator. Highly stable oscillator circuit employed by LNBs and BDCs (block downconverter).

DTCP

Dynamic Tunnel Configuration Protocol. The DTCP protocol is a lightweight datagram protocol.

DVB

Digital Video Broadcasting. A group of over 200 organisations from 23 countries which developed system specifications for the transmission of MPEG-2 digital signals by satellite, cable and terrestrial links. These specifications were passed through the European Telecommunications standards Institute to form an ETSI standard.

DVMRP

Distance Vector Multicast Routing Protocol. A protocol for gateways that uses a dense mode IP multicast scheme. It is based on RIP and uses IGMP to exchange routing datagrams with neighboring gateways. (see RFC 1812).

Encapsulation

Taking data formatted for one protocol and enclosing it within another protocol in order to transmit the data successfully accross a type of network the original protocol was not designed for.

Encrypt

Using cryptography to encode data for security purposes for transmission over a public network. The original text, or plain text, is converted into a coded equivalent called ciphertext via an encryption algorithm. The ciphertext is decoded (decrypted) at the receiving end with the use of a decryption key.

Ethernet

Ethernet is the most widely used local area network (LAN) technology. The original and most popular version of Ethernet supports a data transmission rate of 10 Mb/s. “Newer versions of Ethernet called fast“Ethernet and Gigabit Ethernet support data rates of 100 Mb/s and 1 Gb/s (1000 Mb/s). An Ethernet LAN may use coaxial cable, special grades of twisted pair wiring, or fiber optic cable. Bus and Star wiring configurations are supported. Ethernet devices compete for access to the network using a protocol called Carrier Sense Multiple Access with Collision Detection (CSMA/CD).

FEC

Forward Error Correction. A technique for improving the robustness of data transmission. Excess bits are included in the outgoing data stream so that error- correction algorithms can be applied upon reception.

Firmware

A category of memory chips that hold their content without electrical power and include ROM, PROM, EPROM, and EEPROM technologies.

Flash card

A type of memory storage device approximately the size of a matchbox, capable of recording several megabytes of (usually compressed) digitized audio files or data files.