Collaborative Multimedia Annotation using a Centralized Document Server (01-Sep-1995)

Collaborative Multimedia Annotation using a Centralized Document
Server

      A centralized document server contains hardware and software to
efficiently ship files to users on demand.  All members in a group
session communicate directly with the server which acts as a clearing
house for information and control.  The server's tasks include
distributing documents as needed and tracking future document needs.

      A document server is either a souped-up workstation or a file
server whose central task is to distribute documents and manage the
annotation subsystem of the collaborative desktop viewing system.
Let us assume that a dedicated machine is available, which will
henceforth be referred to as the server.

      Traditionally collaborative efforts have implied that the
members of a joint session exchanged information and data.  This
exchange has always been between peer workstations.  The inherent
weakness of this system is that it handles new entrants to the
session and temporary absences of users from the system inadequately.
Document and files containing the contents of the annotations
(annotation files) have to be sent to every new user by a user
nominated for this task.  While this process is satisfactory for
small files sizes it is very inefficient for large files.  The
transmission time of files is a function of the size of the files
involved.  For this period of time collaboration among the members of
the group is suspended.

      The use...