On bounded degree plane strong geometric spanners

Given a set P of n   points in the plane, we show how to compute in O(nlogn) time a spanning subgraph of their Delaunay triangulation that has maximum degree 7 and is a strong plane t-spanner of P   with t=(1+2)2⁎δ, where δ is the spanning ratio of the Delaunay triangulation. Furthermore, the maximum degree bound can be reduced slightly to 6 while remaining a strong plane constant spanner at the cost of an increase in the spanning ratio and no longer being a subgraph of the Delaunay triangulation.