This paper presents a web based history tool for multicast based e-meeting systems. The tool allow users to see past events and activity graphs of current and past sessions. Video snapshots are stored when events are reported, making it possible to quickly get an overview of the history of a session. This tool has several uses such as a quick and easily accessible way to improve group awareness, monitoring and review of meetings and lectures. 1

ii This thesis presents the use of wearable computers as mediators for human to human communication. As the market for on-body wearable technology grows, the importance of efficient interactions through such technology becomes more significant. Novel forms of communication is made possible due to the highly mobile nature of a wearable computer coupled to a person. A person can, for example, deliver live video, audio and commentary from a remote location, allowing local participants to experience it and interact with people on the other side. In this way, knowledge and information can be shared over a distance, passing through the owner of the wearable computer who acts as a mediator. To enable the mediator to perform this task in the most efficient manner, the interaction between the user, the wearable computer and the other people involved, needs to be made as natural and unobtrusive as possible. One of the main problems of today is that the virtual world offered by wearable computers can become too immersive, thereby distancing its user from interactions in the real world. At

In recent years, broadband networks have come into wide use in many house-holds as the progress of information network technology and the demand for network systems that communicate each other in a large-scale group has in-creased. To achieve such a type of network systems, we need to solve how to keep secure communication among group members. In the future, the demand for such a communication will be increased in the project in which more compa-nies participate. Moreover, there is a possibility that the communicated data becomes large data such as video data.