The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 21, 1999
Filed:
Aug. 29, 1997
Richard C Waters, Concord, MA (US);
David Anderson, Belmont, MA (US);
Mitsubishi Electric Information Technology Center America, Inc., Cambridge, MA (US);
Abstract
A system for fast, efficient and reliable communication of object state irmation among a group of processes combines the use of a fast, but lossy and thus unreliable communications channel to the group of processes and a server coupled to the group for providing data which has been lost in the multicasting. In one embodiment, a central server supports reliability and rapid joining while using UDP multicast messaging to achieve rapid interaction and low bandwidth. Differential messages are sent over the lossy channel to compactly describe how to compute the new state of an object from any of several previous states. Such a description can be interpreted even if some number of prior descriptions were not received, greatly reducing the need for explicit, round-trip message repairs while also conserving bandwidth. In one embodiment, the central server communicates with each member of the group over a reliable channel to robustly detect and repair objects affected by lost messages.