For HD cameras, see Gennum's&nbsp;<a href="http://www.gennum.com/newsroom/pdfs/Aviia_Release_02252009.pdf">HD over Coax for Surveillance</a>&nbsp;announcement from a few months ago. The solution is called&nbsp;Aviia [link no longer available].&nbsp;
Avilia offers 1080p / 30 fps Serial Digital video up to 100 meters with Power and data over Coax. However, maximum distance specified for this solution using RG-59 is 100 meters compared to 300 meters for traditional analog CCTV.
Gennum is manufacturing transmitters (<a href="http://www.gennum.com/video/products/gv7600">GV7600</a>) and receivers (<a href="http://www.gennum.com/video/products/gv7605">GV7605</a>) for this solution.

Gennum's HD Offering