1245011L2 (ADTRAN)

The ADTRAN E1 HDSL LTU is the Exchange Office Transceiver Unit which works with the NTU and/or REG to establish E1 (2.048 Mbps) data rates over a local loop. The LTU plugs directly into the ADTRAN Enhanced 220 (E220) shelf. When deployed in an E220 shelf, this LTU becomes part of a larger HDSL system configuration. Through the backplane of the E220 shelf up to 13 LTUs can communicate with an ADTRAN shelf controller known as the HDSL Fuse/Alarm Control (HFAC) unit. Up to 100 shelf controllers can communicate to a single system controller known as the HDSL Central Office Terminal Controller (HCOTCTL). This architecture provides a single point of interface to as many as 1299 HDSL E1 circuits. HDSL local loop operation is independent of the shelf chosen to deploy the LTU units. The E1 LTU Housing is capable of performing loop termination and designed to accept any standard Type 220 plug-in card. For non-loop powered units, the E1 LTU Housing can provide power to the circuit card through an external power supply.