Fig. 2From: Geographical model-derived grid-based directional routing for massively dense WSNs \(\tilde {f}_{{i},{j}}\) and . The definition domain of f (e.g., T or D) is divided into equally spaced grids with a grid size h. is the grid point located at the ith column and the jth row. \(\tilde {f}_{{i},{j}}\) is the value of f at . The set of grid points, marked by black circles, in A is denoted as . The grid points marked by white circles are not in Back to article page