Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberCA2062841 A1
Publication typeApplication
Application numberCA 2062841
Publication date16 Sep 1992
Filing date12 Mar 1992
Priority date15 Mar 1991
Also published asCA2062841C, DE69217096D1, DE69217096T2, EP0503663A1, EP0503663B1, US5475675
Publication numberCA 2062841, CA 2062841 A1, CA 2062841A1, CA-A1-2062841, CA2062841 A1, CA2062841A1
InventorsRyuichi Kondo, Haruo Yamashita, Tomohiro Ishihara, Toshiyuki Sudo, Takaaki Wakisaka
ApplicantRyuichi Kondo, Haruo Yamashita, Tomohiro Ishihara, Toshiyuki Sudo, Takaaki Wakisaka, Fujitsu Limited, Nippon Telegraph & Telephone Corporation
Export CitationBiBTeX, EndNote, RefMan
External Links: CIPO, Espacenet
Apparatus and method for non-stop switching in asynchronous transfer mode
CA 2062841 A1
Abstract
According to the present invention, when a current system is switched to a spare system in a transmission system in an asynchronous transfer mode, empty cells transmitted in the current and spare systems are detected, and thereby a timing for switching the current system to the spare system is determined. When no phase difference is existent between the current and spare systems, an empty cell is detected in both the current and spare systems at the same time. Therefore, the current system is switched to the spare system, when an empty cell is detected in both the current and spare systems at the same time. When a shade difference is existent, if an empty cell is detected either in the current or spare systems, another empty cell is inserted in to the systems. Then, the data of the empty cell in a spare system is saved. After the empty cell in a current system passes, the current system is switched to the spare system. When a phase difference of at least one cell is existent, and if an empty cell comes earlier in current system, empty cell are kept inserted form when the empty cell is detected in the current system until an empty cell is detected in the spare system.
After that, the current system is switched to the spare system. When an empty cell comes earlier in a spare system, the data of the cell in the spare system is saved from when the empty cell is detected until an empty cell is detected in the current system. After that, the current system is switched to the spare system.
Description  available in
Claims  available in
Classifications
International ClassificationH04L12/70, H04J3/00, H04L1/22
Cooperative ClassificationH04L49/552, H04L2012/5627, H04L2012/5674
European ClassificationH04L49/55A
Legal Events
DateCodeEventDescription
12 Mar 1992EEERExamination request
14 Mar 2011MKLALapsed