The present invention relates to a terminal device and a communication method for radio communication or communication over the Internet.
At present, content or other information is generally downloaded from the Internet by using portable terminals, such as personal computers or mobile phones. However, when servers that store the content and the like distribute them to data terminals, such as personal computers or mobile phones, larger server systems are required as the number of data terminal users increase. Since the number of data terminals that can access one server is limited, many more server systems must be provided in order to overcome this limitation and therefore a lot of investment is required. Additionally, a high-speed and high-capacity communication network is required in order for these data terminals to simultaneously access the server.
Network technologies for solving the problems described above include a multicast technology. With the multicast technology, data is simultaneously transmitted to a number of data terminals. The multicast technology distributes information within a predetermined bandwidth of an information network without specifying the receivers of the information. In contrast, unicast technology transmits data in one-to-one correspondence, in which a server only transmits data to one data terminal. The larger the number of data terminals, the heavier the load on the server with unicast technology.
However, even in multicast communications, it is difficult to say whether the operating method at the data terminals that receive the content and other information, for example, the operation of various buttons on a mobile phone or a portable terminal, is intuitive for people. Furthermore, although current personal computers and the like are becoming easy to use, mixed operations of a keyboard and a mouse make it difficult for beginners or elders to operate personal computers.