The speed of light under the IST and Lorentz Transformations
  We expand the IST transformation to three-dimensional Euclidean space and derive the speed of light under the IST transformation. The switch from the direction cosines observed in K to those observed in K-prime is surprisingly smooth. The formulation thus derived maintains the property that the round trip speed is constant. We further show that under the proper synchronization convention of K-prime, the one-way speed of light becomes constant. 
Chandru Iyer