Local area network modem
US5115451A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 14, 1988 |
| Grant date | May 19, 1992 |
| Priority date | — |
| Expiry date | Oct 14, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/00
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A local area network modem which meets the stringent signalling requirements of the IEEE 802.4 standard. The modem supports loopback commands by insuring that the receiver and transmitter portions are in phase-synchronism, regardless of the physical distance between the modem and upper layer control circuitry. The transmitter also uses only two digital signal wires to specify which of a number of functions are to be performed by the transmitter analog components. An automatic gain control (AGC) circuit is included which eliminates a number of problems associated with prior designs. In particular, the modem's receiver monitors itself to automatically correct drift in phase and gain control adjustment, without intervention from the upper layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.