Finding an effective distance between T-cell and B-cell using S/W ARQ in an immune system communication

In this paper, we present the effective distance between T-cell and B-cell in an immune system using Stop and Wait (S/W) Automatic Repeat Request (ARQ). The concentration of the molecules can be increased by increasing the transmitting number of molecules but it may reduce the performance of communication due to higher collision or interference with other molecules. It is also reported in the literature that the concentration of the emitted molecules reduces if the distance from Transmitter (Tx) to Receiver (Rx) increases. Thus, this paper mainly focuses on enhancing the receiver's capture probability and higher successful complete transmission of the desired molecules by obtaining the effective distance from T-cell to B-cell. In order to find the effective distance, T-cell transmits the molecules 1 (Interleukins-2) to B-cell, upon successful reception of molecules 1, antibodies (molecules 2) transmit back to T-cell. Then, the effective distance of an immune system can be obtained after T-cell detects the concentration of the molecules 2 with respect to time. Different schemes of S/W ARQ protocols have implemented in Molecular Communication (MC) but it requires retransmission of duplicate copies due to the lack of addressing an effective distance. Thus, the simulations are performed in MATLAB and the results obtain higher capture probability and also successful complete transmission of the desired molecules.