  The $6j$-symbols for representations of the $\mathrm{SU}(2)$ quantum group
are given by Hahn-Exton $q$-Bessel functions. This interpretation leads to
several summation identities for the $q$-Bessel functions. Multivariate
$q$-Bessel functions are defined, which are shown to be limit cases of
multivariate Askey-Wilson polynomials. The multivariate $q$-Bessel functions
occur as $3nj$-symbols.
