Error detection/correction and fault detection/recovery – Pulse or data error handling – Error/fault detection technique
Reexamination Certificate
1998-12-22
2001-08-21
Decady, Albert (Department: 2784)
Error detection/correction and fault detection/recovery
Pulse or data error handling
Error/fault detection technique
Reexamination Certificate
active
06279139
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a transmission system which connects communication devices with a transmission path and a receiving path, and performs bi-directional data communication synchronizing the transmission path and the receiving path.
2. Description of Related Art
In a transmission system which performs bi-directional data communication, transmission quality may deteriorate on transmission paths. A transmission error is an example of transmission deterioration. Quality deterioration, such as a transmission error, is caused, for example, by an age-based change of characteristics of an amplifier and a timing regeneration circuit equipped on a transmission path, and the alteration of transmission data caused by an accident.
An operator of a transmission system must maintain the transmission system by constantly detecting the degree of transmission errors.
Parity check is one method to detect a transmission error. In parity check, a “0” or “1” parity bit is added to transmission signals to regulate the transmission signals, and a communication device at the receive side detects a transmission error by judging whether this regularity is maintained after transmission.
Another method to detect a transmission error is to return data from the communication device at the receive side to the communication device at the transmission side, comparing the transmission signals and returned signals by the communication device at the transmission side.
In parity check, the communication device at the receive side can detect transmission quality in real-time, however the communication device at the transmission side cannot detect the transmission quality. That is, with known methods, it is impossible for the communication device at one end to detect transmission quality of both the transmission path and receiving path.
The method for returning receive signals, on the other hand, decreases transmission speed substantially because primary communication is stopped during the return of data.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a transmission system which can detect the transmission quality of both a transmission path and a receiving path, without dropping transmission speed substantially.
The transmission system related to the present invention comprises the first operation means installed in a master communication device for computing a parity bit of a data constellation including main data, the second operation means installed in a slave communication device for performing parity check of main data received from the above mentioned master communication device, the third operation means installed in the slave communication device for computing a parity bit of a data constellation including the main data and output signals of the second operation means, and the fourth operation means installed in the master communication device for performing parity check of the main data received from the slave communication device.
In a system having this configuration, if the result of parity check by the second operation means indicates error generation, the result of parity check by the fourth operation means always indicates error generation. Therefore, the master communication device can detect error generation in the data which the master communication device transmits to the slave communication device.
REFERENCES:
patent: 4947366 (1990-08-01), Johnson
patent: 5136594 (1992-08-01), Sharp
patent: 5349683 (1994-09-01), Wu et al.
patent: 5392424 (1995-02-01), Cook
patent: 5515507 (1996-05-01), Byers et al.
patent: 5784393 (1998-07-01), Byers et al.
patent: 6098179 (2000-08-01), Harter, Jr.
patent: 3-74946 (1991-03-01), None
patent: 5-88995 (1993-04-01), None
Eu, H.J. et al. (A new performance estimation technique for digital transmission systems using a single parity check code; IEEE, Mar. 18, 1988).*
Matsuoka, S. et al. (Classified path restoration scheme with hitless protection switching for large-capacity trunk transmission networks; IEEE, Nov. 17, 1995).*
Tzeng, F.F et al.(Error protection for low rate speech transmission over a mobile satellite channel; IEEE, Dec. 5, 1990).*
Dhawan, S.; et al.(Design of self-checking sequential machines; IEEE, Oct. 1988).*
Redinho et al.(Multi-bit Correcting Data Interface for Fault-Tolerant Systems;IEEE, Apr. 1993).*
Sharp et al.(Detection of Variable Message Lengths for NATO Improved Link Eleven Using CRC Codes; IEEE, Nov. 1991).*
Napolitano et al.(Fault-Tolerance in a High-Speed 2D Convolver/Correlator: Starloc; IEEE, Jun. 1989).
Burdett James R.
De'cady Albert
Frank Robert J.
Lamarre Guy J
OKI Electric Industry Co., Ltd.
LandOfFree
Transmission system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Transmission system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transmission system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2504704