Five-Dimensional Mechanics as the Starting Point for the Magueijo-Smolin   Doubly Special Relativity
  We discuss a way to obtain the doubly special relativity kinematical rules (the deformed energy-momentum relation and the nonlinear Lorentz transformations of momenta) starting from a singular Lagrangian action of a particle with linearly realized SO(1,4) symmetry group. The deformed energy-momentum relation appears in a special gauge of the model. The nonlinear transformations of momenta arise from the requirement of covariance of the chosen gauge. 
B. F. Rizzuti and A. A. Deriglazov
hep-th gr-qc