System and method for reducing latency in software modem for high-speed synchronous transmission
US6233250A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1998 |
| Grant date | May 15, 2001 |
| Priority date | — |
| Expiry date | Nov 13, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2012/5682
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An ADSL physical transmission layer retrieves data to be transmitted from either a transmit data buffer, or a dummy cell buffer in the case when no actual data is being transmitted to maintain a continuous data stream in an ADSL data link. The ADSL physical transmission layer and an associated ATM protocol layer are implemented as an interrupt service routine and delayed procedure call respectively in an ADSL software modem application. Because the ATM protocol layer does not fill the transmit data buffer with dummy cell data, it is simpler and faster. Moreover, latency is minimized, and overall system throughput enhanced since the maximum latency is independent of any operating system latency, and is no greater than the size of the cell stored in the dummy cell buffer. The invention has significant potential for beneficial use in an ADSL based software modem where wide variations in performance and latency of computing systems pose engineering challenges in maintaining a continous data link between a real time transceiver and a non-real time operating system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.