In the literature, various terminologies are used for describing remote accessible or virtual online experiments. To avoid confusion this article discusses these terms before the principal section.
A Distance Lab is a web platform offering any kind of online accessible experiment. This can be a remote or a virtual lab. These two kinds of labs are described next. In my case, the term DistanceLab is used for a web platform including several labs accompanied by booking and user management modules.
A remote lab (or online lab) enables actors (such as students or employees) to carry out experiments over the Internet which are normally performed in real-time physical studies in educational laboratories. Compared to a normal laboratory, additional equipment is needed to prepare traditional labs for online access.
The following figure illustrates these necessary changes.
In a conventional laboratory environment, the actor uses the equipment with his or her own hands, getting direct feedback to any actions performed. When pressing a button the actor will see what the „reaction“ of the lab is, without any delay. In a remote lab, the actor is connected by a personal computer (or any other device, like a smart phone or tablet pc) to the Internet. The actor is performing by utilising specific software or just by accessing a web application running in any common web browser. The user’s actions are transmitted to a receiver system (in most cases a computer system) with a public IP address. Naturally this receiver system is preceded by a user/laboratory management system, dealing with access rights and booking issues. This case is not illustrated here. The receiver system is directly connected to the laboratory equipment, enabling the actor to perform those standard actions to the hardware which are common for that specific kind of experiment.
Advantages of remote labs compared to traditional ones
In a common lab course, mostly during practical work sessions as defined in the engineering curriculum, learners are encouraged to perform their exercises at a specific time, usually in a group of students, during the opening hours of their institution. There is often no consideration for disabled learners or for individual time constraints of the participants. Another problem is the availability of sufficient lab places. Especially, poor institutions may not offer costly experiments. Due to the nature of remote labs there is the possibility of sharing equipment, not only between students at the home institution but also between institutions themselves.
Virtual and Simulation Labs
The integration of virtual labs (see the following figure) into a lab management system is generally easier than integrating remote hardware based labs. Some of the literature uses the terms „remote lab“, „online lab“, „cyber-enabled lab“ and „virtual lab“ synonymously but, while the first three are the same, „virtual lab“ may not be used interchangeably. A virtual lab is a „laboratory“ consisting of a specific piece of software. This software may be a proprietary one but also can be a web service or simulated hardware. The common case for all virtual labs is that real experiments are virtualised or simulated in this software, in most cases dealing with a challenge close to reality.
A virtual lab can be accessed like a real hardware lab. The actor is performing his actions from a distance by using an ordinary computer system sending his input over a network (in most cases involving Internet transmission) to a receiver system which will be in most cases linked directly to the virtual lab. In specific cases a virtual lab may involve different virtual machines (as in a network experiment, where students have to set-up a network infrastructure from a distance) or additional server systems (database systems among others) which are necessary for the virtual lab. The system itself directly sends the feedback over the communication channel back to the actor’s personal computer. All computations are done in the virtual lab and only feedback to the user input is sent back.
Advantages and disadvantages of virtual labs
Virtual labs have some advantages compared to real hardware labs. If the virtual lab is a software service then once the lab is set up it can be used by many students simultaneously, restricted only by the computational power of the host computer. It is also more robust than real equipment; a student cannot destroy the hardware whilst adjusting some settings or failures in programming. Another benefit is monetary. The system can be easily duplicated without paying additional costs. Of course, virtual labs also have disadvantages in comparison to real (remote) ones. A virtual lab can never perform exactly the same as real hardware in all cases. As it is impossible to include all environmental parameters in the virtualisation, a virtual lab will sometimes react differently to a real one.
The best solution seems to be a combination of virtual and remote labs to get benefits from both of them.
A general approach, also used in our consortium, is to use the virtual devices for basic education to teach basic system thinking and to get familiar with the hardware. In later steps the learners switch to real hardware.