  It is shown that a realistic, controlled bidirectional remote state
preparation is possible using a large class of entangled quantum states having
a particular structure. Existing protocols of probabilistic, deterministic and
joint remote state preparation are generalized to obtain the corresponding
protocols of controlled bidirectional remote state preparation (CBRSP). A
general way of incorporating the effects of two well known noise processes, the
amplitude-damping and phase-damping noise, on the probabilistic CBRSP process
is studied in detail by considering that noise only affects the travel qubits
of the quantum channel used for the probabilistic CBRSP process. Also indicated
is how to account for the effect of these noise channels on deterministic and
joint remote state CBRSP protocols.
