Multiplex communications – Fault recovery – Bypass an inoperative channel
Patent
1995-07-17
1997-05-20
Safourek, Benedict V.
Multiplex communications
Fault recovery
Bypass an inoperative channel
371 682, 455 8, H04L 122
Patent
active
056318960
ABSTRACT:
A hitless path switching method without a bit loss. The same digital line signals on a working path and a protection path are continuously monitored independently for bit errors. If a bit error occurs in the working path and no bit error occurs in the protection path, a switching trigger is produced and a switching operation from the working path to the protection path is performed on a data block basis. Only correct data are transferred to downstream apparatuses. Reliable hitless switching is achieved not only in response to a failure in a path, but also in response to a bit error. Using data blocks of one frame length with an indicator for bit error checking placed at its beginning or top makes effective switching possible.
REFERENCES:
patent: 4246656 (1981-01-01), Wood et al.
patent: 4349914 (1982-09-01), Evans
patent: 5051979 (1991-09-01), Chaudhuri et al.
patent: 5481549 (1996-02-01), Conti et al.
"General Aspects of Digital Transmission Systems; Terminal Equipments," International Telegraph And Telephone Consultative Committee, vol. III--Facsimile III.4, 14-25 Nov. 1988, pp. 109-174.
NTT Network Systems Development Center, p. 3-235, "A Study of Hitless Switching Function on SDH Network", Kenji Gotoh et al.
NTT Network Systems Development Center, p. 3-338, "Protection System for SDH Optical Fiber Transport Module", Yukio Kobayashi et al.
N. Kawase et al, "Route diversity with hitless path switching", Electronics Letters, vol. 30, No. 23, Nov. 10, 1994, pp. 1962-1963 (Engl. & Japanese).
Kazuhiro Nishihata, "Current Status of the Trunk Transmission System and Future Development", NTT Review, vol. 5, No. 2, Mar. 1993, pp. 53-58.
Ralph Ballart et al, "Now It's the Standard Optical Network", IEEE Communications Magazine, Mar. 1989, pp. 8-15.
R. Kawamura, "A Failure-resistnat Virtual Path Scheme for ATM Networks", Technical Report of IEICE, Inst. of Electronics, Information and Communication Engineers, CS94-196, DSP94-118 (1995-01), pp. 47-54 (Engl & Japanese.
Kawase Nobuyuki
Uematsu Yoshihiko
Yamabayashi Yoshiaki
Nippon Telegraph and Telephone Corporation
Safourek Benedict V.
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