A webcast virtual laboratory on a frequency modulation experiment

A number of Internet remote experimentation has been successfully developed for teaching and research purposes in the National University of Singapore (NUS). As only one user can assume control of the apparatus in any physical or remote experiment, the access to these experiments has hitherto been only been limited to single users one at a time. Without any increase in the hardware experimental apparatus needed, this paper presents a new webcast based approach for remote experimentation that allows several observing users to view an existing remote experimental session while it is being conducted by a main user. Multicast, the state of the art technology, is being adopted to implement the webcasting capability for remote experimentation purposes with some degree of reliability provided. In multicast, only one copy of the same data is sent to a group address, reaching all the observing users in a particular remote laboratory session. Thus, the system can be accessed by as many users as possible without overloading network and server resources. This is particularly useful as the number of users that may want to observe the experiment cannot be predicted in advance. The webcast virtual laboratory can be accessed at the following web site, http://vlab.ee.nus.edu.sg/vlab 1/freqmod/index.html.