Drug Release Management for Dynamic TDMA-Based Molecular Communication

In this paper, we design a drug release mechanism for dynamic time division multiple access (TDMA)-based molecular communication via diffusion (MCvD) in case of having multiple transmitter units and a single receiver. In the proposed scheme, the communication frame is divided into several time slots in which a transmitter nanomachine is scheduled to convey its information by releasing the molecules into the medium. To optimize the number of released molecules and the time duration of each time slot (symbol duration), we formulate multi-objective optimization problems whose objective functions are the bit error rate (BER) of each transmitter nanomachine. Based on the number of released molecules and symbol durations, we consider four cases, namely: “fixed-time fixed-number of molecules” (FTFN), “fixed-time varying-number of molecules” (FTVN), “varying-time fixed-number of molecules” (VTFN), and “varying-time varying-number of molecules” (VTVN). For the channel model, we consider a 3-dimensional diffusive environment with drift in three directions. Simulation results show that the FTFN approach is the least complex one with BER around <inline-formula> <tex-math notation="LaTeX">${10}^{-2}$ </tex-math></inline-formula>, but, the VTVN is the most complex scenario with the BER around <inline-formula> <tex-math notation="LaTeX">${10}^{-8}$ </tex-math></inline-formula>.