Some systems fulfil requests a long time after they are submitted so they cannot expect the user to wait around. Once such system is the Bradford Robotic Telescope - a remote telescope developed at the University of Bradford. The system is equipped with many weather sensors. If it is a clear night then jobs are scheduled according to which areas of the sky are visible, how long a job has been waiting and what priority the user has. An e-mail confirmation is telling the user where to find their pictures on the telescope s web site.
Users have control over some equipment and receive feedback from it.
For example, a remote robot might allow the user to drive it around and see where it is going. If several people want to use the robot then they have to queue and take turns, just as in a real lab. The simplest way of queuing is to rely on social protocols. Another option is to use a queue at the server end that alerts users when it is their turn. Some remote labs require re-initialising between users.