We investigate the global structure of the advection dominated accretion flow around a Schwarzschild black hole where the accretion disc is threaded by toroidal magnetic fields . We consider synchrotron radiative process as an effective cooling mechanism active in the flow . With this , we obtain the global transonic accretion solutions by exploring the variety of boundary conditions and dissipation parameters , namely accretion rate ( { \dot { m } } ) and viscosity ( \alpha _ { B } ) . The fact that depending on the initial parameters , steady state accretion flows can possess centrifugally supported shock waves . These global shock solutions exist even when the level of dissipation is relatively high . We study the properties of shock waves and observe that the dynamics of the post-shock corona ( hereafter , PSC ) is regulated by the flow parameters . Interestingly , we find that shock solution disappears completely when the dissipation parameters exceed their critical values . We calculate the critical values of viscosity parameter ( \alpha ^ { cri } _ { B } ) adopting the canonical values of adiabatic indices as \gamma = 4 / 3 ( ultra-relativistic ) and 1.5 ( semi-non-relativistic ) and find that in the gas pressure dominated domain , \alpha ^ { cri } _ { B } \sim 0.4 for \gamma = 4 / 3 and \alpha ^ { cri } _ { B } \sim 0.27 for \gamma = 1.5 , respectively . We further show that global shock solutions are relatively more luminous compared to the shock free solutions . Also , we have calculated the synchrotron spectra for shocked solutions . When the shock is considered to be dissipative in nature , it would have an important implication as the available energy at PSC can be utilized to power the outflowing matter escaped from PSC . Towards this , we calculate the maximum shock luminosity and discuss the observational implication of our present formalism .