The next wave of digital throughout the home will likely be whole-house distribution of high-definition (HD) signals to multiple displays in multiple rooms. The only problem is that it can’t be done without stepping on some land mines.

HDMI (high-definition multimedia interface) and DisplayPort, for example, were developed to handle single-point distribution and limited to about 30 feet. Digital extenders such as EDID (extended display identification data) can help, querying the display as to its native resolution and adjusting the source accordingly. CEC (consumer electronics control) is a device control protocol that will shut down a display if it no longer senses a signal from the last source. But if the user is just switching to a different source, the display may be shut down anyway, prompting an unnecessary service call. Then there’s HDCP (high-bandwidth digital content protection) that can’t readily distribute Blu-ray signals throughout the house thanks to authentication issues, and the fact that Blu-ray only allows up to eight authentication keys maximum. That limits the number of displays it can be distributed to and shuts the player down if it’s directed to send to a ninth location.

Crestron says it has a solution with its Digital Media series of products that started shipping earlier in 2009. Crestron communications director Jeff Singer points out one of the central ironies of the digital era: technology solutions that become technological booby traps. “HDCP was developed to prevent illegal distribution of high-def content, and now it can potentially prevent distribution of all HD signals in the home,” he says. “EDID can tell the [signal] source what the native resolution of a particular display is, but what if the source doesn’t support one of those native resolutions? That can result in a degraded picture. It’s complicated.”

The bottom line for builders, for whom home high-definition capability will be important in the very near future, is to emphasize Ethernet cabling as part of the structured wiring package.