In the home network, transmission media are classified into cable systems and wireless systems. Although optical fiber and metal cable can transmit data at high-speed and with stability, installation between rooms is not as easy as that of wireless systems. The use of electrical power lines and telephone lines which have already been installed in the home is also being examined despite its smaller transmission capacity. A wireless home network system has the significant advantage of easy installation, in comparison with cable systems. Since infrared beams do not pass through walls, their use is limited to within the room.
Radio waves are capable of supporting mobile communication between rooms.
They, however, might suffer from radio attenuation caused by the walls and other obstacles, resulting in unstable transmission. This method might also raise concern over security issues, since the transmitted data could be intercepted by others. Transmission methods Transmission method Table 1 shows individual systems connected to a home network and their transmission methods. The major transmission methods for cable systems using metal cables are Ethernet or USB2.0 for information appliances, such as personal computers, and IEEE1394 for either information appliances or AV equipment. Wireless system transmission methods include IrDA, which is designed for AV equipment and information appliances using infrared beams, and Bluetooth for information appliances using radio waves.