  A complete classification of the regular representations of the relations
[T,X_j] = (i/k)X_j, j=1,...,d, is given. The quantisation of RxR^d canonically
(in the sense of Weyl) associated with the universal representation of the
above relations is intrinsically "radial", this meaning that it only involves
the time variable and the distance from the origin; angle variables remain
classical. The time axis through the origin is a spectral singularity of the
model: in the large scale limit it is topologically disjoint from the rest. The
symbolic calculus is developed; in particular there is a trace functional on
symbols. For suitable choices of states localised very close to the origin, the
uncertainties of all spacetime coordinates can be made simultaneously small at
wish. On the contrary, uncertainty relations become important at "large"
distances: Planck scale effects should be visible at LHC energies, if processes
are spread in a region of size 1mm (order of peak nominal beam size) around the
origin of spacetime.
