Typical connections from an HDMI source such as a Blu-ray player or satellite box to an HDMI display would be an HDMI cable. Unfortunately, the downside to an HDMI cable is there is a limit to how far HDMI data can be transmitted. The theoretical limit is 50 feet, and it’s incredibly rare to find an HDMI cable over 25 feet. In addition, Longer HDMI cables can be pretty expensive.
The solution is to use an HDMI extender. These devices will convert the HDMI signal to something that can sustain the high bandwidth required over a longer distance. One of the most accessible transmission methods is using serial communication over Cat 5, 6 or 7 Ethernet cable. HDMI would be transported over Ethernet Cat 5e / 6 / 7 cables using an HDMI Extender over Cat cable. An HDMI Extender over Cat 5e / 6 / 7 cables consists of a Transmitter and a Receiver. Additionally, you can extend other signals such as IR remote control commands, USB and RS-232. You can also buy an HDMI splitter extender over Ethernet and use it for viewing the HDMI source on several televisions.
It is recommended that you use the best quality cable available. Cat 6, Cat 7, and Cat 8 cables all look the same on the outside, but there is some significant internal differences between them. The higher the number, the more twists there are in the cabling. Basically, the higher number cable would help to provide better performance and farther in distance. Cat 6 shielded and Cat 7 yields the best performance and most immune to interference.