AM2048

The AM2048 is used to provide reliable high speed transmission links over copper. Where range allows, existing telephone grade copper infrastructure can be given a new lease of life and used to carry high speed data traffic.

Where variable rate interfaces are used at both ends, such as V.35 or X.21, rate adaption allows the units to automatically find the maximum operating data rate for a given line.

The E1 interfaces are typically used to provide inter PBX connections between corporate locations. Where range does not allow the full 2Mbps data to be transmitted, then E1 interfaces can still be used, but only selected timeslots are transmitted.

Typically, the modems are used to provide leased line circuits over rented copper pairs (e.g. in the UK, BT EPS8 and EPS9 baseband circuits.) Telcos also use AM2048 in their own networks to extend E1 interfaces out from the exchange SDH equipment to the customer premises.

Technical Details
The AM2048 is available as a desktop unit, or as a 19 inch rackmount version if many circuits are terminated at the same point.

The transmission system uses the CAP line code. This is an adaptive echo cancelling system that allows the transmission and reception of data on a single pair of wires. The line coding is designed to shape the transmitted power spectrum to minimise the interference with other systems, particularly ADSL.

The system is symmetric, i.e. the upstream and downstream data rates are the same. This is particularly important for business users where peer-to-peer connections are needed and the same volume of traffic is flowing in both directions.

Two pair transmission mode splits the payload data evenly between each of the pairs thus reducing the transmission rate required on each pair. Reducing the transmission line rate extends the range that can be reached for a given user rate.

The line circuit contains special fast acting devices that provide protection against high voltage and current surges. Because copper transmission networks are prone to induced voltages from ground currents caused by external events such as lightning, mains protection switching, mains contact, RF etc. the protection devices maximise the availability of the circuit.