a mobile computing device to the als infrastructure of the classroom or presentation hall in order to access the networked resources participate in an interactive lecture or presentation session and view the interactive multimedia contents of an als infrastructure of a classroom or presentation hall a participant must first authenticate and have his her registered mobile computing device join the als infrastructure in accordance to various embodiments participants are divided into two groups lecturer or presenter group and student or audience group the processes of participant authentication and joining of a mobile computing device to an als infrastructure are different for these two groups of participants referring to fig3 a the participant authentication and joining of a mobile computing device to an als infrastructure for a participant in the lecturer or presenter group comprises 301 the mobile computing device entering the coverage area of the als infrastructure 302 launching and executing the als application in the mobile computing device 303 the mobile computing device connecting to the als infrastructure 304 a first processing server in the als infrastructure recognizing the mobile computing device has been registered and instructing the mobile computing device to prompt its participant for authentication 305 if the participant of the mobile computing device has a nfc enabled personal security access card the participant can motion the personal security access card.