Remote control 3rd paragraph #0004

BACKGROUND OF THE INVENTION 3rd paragraph

The bottleneck caused by modems can have a significant effect on the speed of remote control operations.
To boost performances, remote control programs try to reduce and minimize the amount of data that needs to be transmitted over the communication lines (LAN or telephone cables).
The refresh of the video image on the display screen of the target PC, which should be duplicated on the controller PC, constitutes the main point in the transmission speed, due to the big quantity of information which has to be transferred.
In the past, remote control programs worked by sending and refreshing the entire image of the target PC screen to the remote PC every fraction of a second.
The constant rate at which the screen images were sent to the controller PC was called the screen refresh rate.
The controller PC screen accurately reflected the target PC screen as changes at the target PC would be included in the next screen refresh.
This approach was, of course, not very satisfactory in term of speed, because of the enormous amount of data to be transmitted at each refresh.
To be continued  #0005
- Anfossi, et al. Screen remote control. U.S.Patent 6,141,022. October 31, 2000.