If we look at the means of communication that human beings use, we find that there are different categories of how we determine the receiver of a message. If we speak, everyone who is at the same location will get the message. If we write a letter, we address someone specific and only that person will get the message. Finally, if we publish something, then everyone who is interested in it can get that information. These ways of communication are also reflected in the Internet. We can send messages to a specific receiver using unicast. If we use multicast, everyone who is interested in the information can tune into the group and receive the messages. Finally, as an equivalent to speech, which is a location-specific way of communication, we find GeoCast.