HDMI is the abbreviation for High Definition Multimedia Interface, a digital video/audio interface technology. HDMI cable is the abbreviation for the connection cable between multiple high definition multimedia, which can transmit uncompressed high definition video and multi-channel audio data in high quality. HDMI cable mainly transmits digital signals, the quality of HDMI cables on the market varies, many HDMI cables in the transmission distance of more than 10 meters after the degree of attenuation is more serious, and in the choice of HDMI cable must buy a suitable length for their own, not too long, otherwise it is not conducive to transmission. Attenuation is the HDMI cable receiving device in how many meters can maintain the signal transmission. In fact, attenuation in the case of higher frequencies, the signal will be more attenuated. When using HDMI cables, the main thing to look at is the quality. If the quality is good, pure copper HDMI cables can generally transmit up to 60 meters. Generally speaking, for best results, the recommended HDMI connection length is usually within 15feet (about 4.6m), and certain better quality HDMI cables can do up to 30feet (about 9m). If the quality control of the cable itself is done well (although not necessarily expensive), there are HDMI cables that can achieve 50feet (about 15m) can also work properly. But when it is this long, the situation will become more delicate, you will probably see the display device side of the "flicker" phenomenon. You may also experience a more serious "handshake problem" - a straight black screen. Of course, then again, if you buy a poor quality informal manufacturers produced by the cable, even if the short distance transmission may still encounter these problems. First: HDMI transmission through the network cable An effective solution to extend the HDMI transmission distance is to transmit via Ethernet cable. Try special adapter devices at home or in the office environment to connect the HDMI signal to the router's Cat5, 5e, 6 and Cat7 network cables, which can also be used to pass audio and video signals in the home theater system. Second: Wired Solutions Active Optical HDMI Cable Extending HDMI transmission via network cable, optical fiber, coaxial cable plus converter is a viable approach. There is also an "active fiber optic HDMI cable" that integrates the fiber optic converter into the HDMI connector. This cable is the same as the ordinary HDMI cable, plug and play, no additional power supply. One end is connected to the signal side, and the other end is connected to the device side, so you can plug it in and use it. Third: Wireless HDMI solutions There is another method of wirelessly connecting HDMI devices. This solution can be achieved in large rooms completely without the use of long distance HDMI cable, usually can support up to 9 to 18 meters. However, some devices may provide coverage of 50m or even longer. The wireless HDMI solution is similar to the solution of extending HDMI through network cables, fiber optic and coaxial cables, also through a short HDMI cable to the source to the transmitter side, through the wireless solution to the receiver side, the receiver side then connected to the display device side through a short HDMI cable.