Note that HDMI Cables with RedMere are directional. One end must be connected to the source device (e.g., blu-ray player) and the other end to the sink/display (e.g., HDTV). Hooking them up backwards will not damage anything, they just won't transmit a signal. Also note that these cables are fully compatible with switches, splitters, matrix devices, etc. They can be used in any application in which a normal HDMI cable can be used and many applications where HDMI extenders would otherwise be required!
If it is only one-way then how can my TV send the HDMI-CEC signal to my receiver ?
Because it isn't only one way. An HDMI cable wouldn't work if it only allowed one way communications. On Redmere cables, the high speed audio and video can only go in one specific direction since it is recovered at the sink, while the rest of the lower speed data flows in the direction it was meant to flow.
Since it is lower speed data it is less prone to have errors at longer distances.