Complete Communications Engineering

VOCAL Technologies continues to provide telephony software solutions to support legacy telecommunications systems even as these systems are supplanted by IP-based communications.

As the public telephone network evolved from simple analog to multiplexed analog carriers to digital carriers and optical carriers, many new conventions and standards were added. And as is typical in this field, very few standards have been successfully deprecated and eradicated. In today’s systems, even though IP-based communications is now the de facto implementation, support of the legacy telecommunications standards is essential.

Low Speed Digital Carrier Systems (DS1) – Multiplexed voice/data carried over twisted pair copper wires.

High Speed Digital Carrier Systems (DS3/4) – Multiple DS1 carriers delivered over fiber optic (SONET) links with local coax cable connections.

Analog Systems (DS0) – Analog circuits/termination found at each end of a twisted pair copper wires.

Terminal Devices – Analog or digital circuits used to support a human-machine interface (HMI) or machine to machine interface (MMI).