One common method involves Alice not using the noisy channel to transmit source states directly but instead preparing a large number of Bell states, sending half of each Bell pair to Bob. The result from transmission through the noisy channel is to create the mixed entangled state p , so that Alice and Bob end up sharing m copies of p . Alice and Bob then perform entanglement distillation, producing m ⋅ ⋅ D ( p ) almost perfectly entangled states from the mixed entangled states p by performing local unitary operations and measurements on the shared entangled pairs, coordinating their actions through classical messages, and sacrificing some of the entangled pairs to increase the purity of the remaining ones. Alice can now prepare an m ⋅ ⋅ D ( p ) qubit state and teleport it to Bob using the m ⋅ ⋅ D ( p ) Bell pairs which they share with high fidelity. What Alice and Bob have then effectively accomplished is having simulated a noiseless quantum channel using a noisy one, with the aid of local actions and classical communication.