Systems and methods for encrypting the output of a card reader in a card authentication system are provided. A roof assembly is provided with first and second roofs that are spaced apart such that the outer roof acts as a heat shield for the inner roof to ensure the interior of the dwelling is a minimum temperature. The TPC information may be applied to a power control process related to a first subframe set, to which the subframe index i belongs, among the plurality of subframe sets.