T1 channel bank control process and apparatus
US5768368A · kind A · utility
Inventors
Key dates
| Filing date | Jan 10, 1997 |
| Grant date | Jun 16, 1998 |
| Priority date | — |
| Expiry date | Jan 10, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/02
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A technique for powering telephone lines using an unbalance current source and current sink; and a technique for improving attenuation/frequency distribution and return loss (impedance matching) of transformer-coupled wire-line communications circuits by using secondary series capacitance and an AC current pump signal source; and a generation of ringing voltage as positive voltage pulses with respect to a negative power supply voltage; and a technique for removal of AC power ripple by using an active linear floating filter for the purpose of powering telephone line circuits, and a technique for injection of real time tone samples into T1 transmissions circuits by use of a T1 framer idle code register. The combination of the above five circuit techniques provides for the hardware implementation of a single printed circuit board embodiment (Line Interface Unit LIU) of a plurality of communications functions including a T1 channel service unit, a ringing generator, power converters, a ringback tone generator, and a channel bank controller. The LIU supports selectable T1 standards of communications. Dual 12-channel telephone line voice cards plug into the LIU card to provide a complete…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.