ADTRAN ISU 2X64 user manual TE1

Glossary

synchronous

1.The condition occurring when two events happen in a specific time relationship with each other, both under control of a master clock. 2. A method of data trans- mission requiring the transmission of timing pulses to keep the sender and receiv- er synchronized in their communication used to send blocks of information.

Synchronous data transmission is used in high-speed data circuits because there is less overhead than asynchronous transmission of characters which contain two ex- tra bits per character to affect timing.

T1

Also T-1. A digital transmission link with a capacity of 1.544 Mbps. T1 uses two pairs of normal twisted wires. T1 normally can handle 24 voice conversations with each conversation being digitized at 64 kbps. With more advanced digital voice encoding techniques, it can handle more voice channels. T1 is a standard for digi- tal transmission in North America.

TA

Terminal Adapter. A DCE that connects to the ISDN S-Interface and enables non- ISDN terminal equipment to communicate over ISDN.

TE1

terminal equipment type 1. ISDN-compatible terminals.

TE2

terminal equipment type 2. Non-ISDN terminal equipment linked at the EIA-232, RS-449, or V.35 interface.

transmission

The dispatching of a signal, message, or other form of intelligence by wire, radio, telegraphy, telephony, facsimile, or other means. A series of characters, messages or blocks including control information and user data. The signalling of data over communications channels.

transmission level

The power of a transmission signal at a point of a transmission facility. It may be measure in absolute terms (dBm) or in a ratio to its level at some reference point (dB).

twisted pair

Two wires twisted around each other to reduce induction (interference) from one wire to the other. Several sets of twisted pair wires may be enclosed in a single ca- ble. Twisted pair is the normal cabling from a Central Office to your home or of- fice, or from your PBX to your office phone. Twisted pair wiring comes in various thicknesses. As a general rule, the thicker the cable is, the better the quality of the conversation and the longer cable can be and still get acceptable conversation qual- ity. However, the thicker it is, the more it costs.

142 ISU 2x64 Dual Port ISDN Service Unit User Manual 61200051L1-1D