Diffusion MRI based microstructural imaging is used to estimate voxel wise intra/extra-cellular volume fraction and compartment diffusivities. Previously proposed techniques like NODDI, SMT models are used to estimate intra/extra-axonal volume fraction, axial and radial diffusivity for each voxel. TEdDI is a framework to estimate intra/extra-axonal T2 in human brain. The proposed TEdDI model requires multiple sets of diffusion dataset varies with echo time. In this study we are proposing SMT based formulation to estimate intra/extra-axonalT2. We also used this formulation to design numerical algorithm that approximate T2 and other parameters for a typical multi-shell diffusion acquisition.