Velbus cable

I will install velbus in a single-family house.
The channels provided for the velbus cable is star-shaped in which each branch is about 15m long. The channels are independent of the power lines. In those circumstances what are the minimum characteristics recommended for velbus cable?
Best Regards.

To interconnect the Velbus modules the use of twisted-pair cable (EIB 2x2x0.8mm2, UTP 8x0.51mm - CAT5 or equivalent) is recommended.