<FONT face=Verdana>We consider an orthogonal relay channel

where the channel from the source to the relay and the channel from the source and the relay to the destination are orthogonal on time. Firstly

the upper bound and the lower bound of the capacity are proposed

and converge to the capacity

where the lower bound is based on partial decode-and-forward. Secondly

to maximize the capacity for Gaussian orthogonal relay channel

the resource allocation is studied. The simulations show that optimizing the time only brings very little loss about capacity compared to maximize all the possible parameters. The optimal time allocation is given analytically when optimizing the time only.