#	 cost	range	 time [µs]
USB	  0.5	  5.0	  500   10
SL	  0.5	100.0	  300   10
RF	  2.0	 30.0	 1800   80
PL	 30.0	 50.0	25000 1300

# cost function explanation:
# Let 'a' be the per-hop cost, and 'r' the range.
# The cost function 'c(x)' at a distance 'x' is:
#
# c(x) = a * (1 + 2 * (x / r)²)
#
# so that c(r) = 2 * c(r / 2)
# i.e., the range is the distance above which
# an intermediate hop is sought for.

