  We define a q-analog of the modified Bessel and Bessel-Macdonald functions.
As for the q-Bessel functions of Jackson there is a couple of functions of the
both kind. They are arisen in the Harmonic analysis on quantum symmetric spaces
similarly to their classical counterpart.
  Their definition is based on the power expansions. We derive the recurrence
relations, difference equations, q-Wronskians, and an analog of asymptotic
expansions which turns out is exact in some domain if $q\neq 1$. Some relations
for the basic hypergeometric function which follow from this fact are
discussed.
