This book mainly focuses on the design of intelligent and effective frame transmission strategies used in the MAC layer of wired or wireless networks. The first introduced strategy is an enhanced genetic algorithm (GA), named hyper-generation GA (HG-GA). It is a scheduler to quickly obtain the near optimal transmission sequence of data frames for dense-wavelength-division-multiplexing (DWDM) optical networks. The second introduced strategy is an M-time inheriting transmission strategy (MITS), and the last is an ACK-based polling strategy (APS). Both MITS and APS can effectively alleviate the degree of transmission contention and then improve the transmission efficiency of wireless networks.